i, i apeeeee teri ets tpt ib et nT ny tT RRL Te ait ithe teh fee hale ae Tidetoe tea Hit | tHe 1 if ; bithas 4; hin pee 8. bese “une F ‘ eet Hit 1 i : it H ; ini HA Pe REE y iMag ating ehed 1G eee ta tat he ihe eat eabe + Tt ie " ; . ta eis ty re ~_ , = Ale ring YAY es ne ee rae 4 cs, ory ~. id Gy a 7 — ~ ™ ‘ “or wit i J th = usa ae cs REPORT ee : \ TENTH MEETING BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE; HELD AT GLASGOW IN AUGUST 1840. LONDON: JOHN MURRAY, ALBEMARLE STREET. 1841. PRINTED BY RICHARD AND JOHN E. TAYLOR, RED LION COURT, FLEET STREET. a Ta, & *% * ¢ \ Ce ee CONTENTS ——>—— > Page Ossects and Rules of the Association ...........2.205 005 v Sreicere and Gounigil) fais vip eaiit ie (es ashes Vorweals } Hac Vili Places of Meeting and Officers from commencement ........ ix Table of Council from commencement ..................4. z ' Officers of Sectional Committees, and Corresponding Members xii PESTO Gi MREIOUER Niel cte inten lars ¢ere ielam aia GRIMS Se ee Ss xiv Reports, Researches, and Desiderata..............ee00000: XVi Recommendations for Additional Reports and Researches in INES Mee Nias bis ol, Quai a, aay Eicon atin ot nlm mois (Lccheig Xxili Synopsis of Money Grants ..................4.. UEFA. s XXxil Arrangements of the General Evening Meetings............ XXxiv Address of the General Secretaries .............. 000.000. XXXV REPORTS OF RESEARCHES IN SCIENCE. Report on the recent progress of discovery relative to Radiant Heat, supplementary to a former Report on the same subject inserted in the 1st volume of the Reports of the British Associa- tion for the Advancement of Science. By the Rev. BapEN Powe tt, M.A., F.R.S., F.R. Ast. S., F.G.S., Savilian Professor of Geometry in the University of Oxford.................. 1 Supplementary Report on Meteorology. By James D. Forsgs, Esq., F.R.S., Sec. R.S. Ed., Professor of Natural Philosophy in ene University Of Edin buteititins vapisiecc. cas < os ve nage wens 37 Report on Professor Whewell’s Anemometer, now in Operation at Plymouth. By Wm. Snow Harris, F.R.S., &c. .......... 157 a2 lv CONTENTS. Page Report on “The Motions and Sounds of the Heart.” By the London Committee of the British Association, for 1839-40... 163 An Account of Researches in Electro-Chemistry. By Professor Scu6nBeEtn, of Basle . Second Report upon the Action of Air and Water, whether fresh or salt, clear or foul, and at various temperatures, upon Cast Iron, Wrought Iron, and Steel. By Ropert Matter, M.R.LA., prose iing. OE. 23/67. b tie eeeed Report on some Observations on Subterranean Temperature. By BOBERTAWERE Pox, Jaq... .. . »., anes), 08)43 4s 5 yas) cet mee - 309 Report on the Observations recorded during the years 1837, 1838, 1839, and 1840, by the Self-registering Anemometer erected at the Philosophical Institution, Birmingham. By A. FoLLertr PSL ER MAR n ator, 5) so UU Ae tRits aewiein ss 6 a .5'ha 321 Report respecting the Two Series of Hourly Meteorological Ob- servations kept at Inverness and Kingussie, at the Expense of the British Association, from Nov. Ist, 1838, to Nov. Ist, 1839. By Sir Davin Brewster, K.H., F.R.S., &. ......... 200 0 349 Report on the Fauna of Ireland: Div. Vertebrata. Drawn up, at the request of the British Association, by W1LL1Am THompson, Esq. (Vice-Pres. Nat. Hist. Society of Belfast), one of the Com- mittee appointed for that purpose................022-008- 353 Report of Experiments on the Physiology of the Lungs and Air- tubes. By Cuarzes J. B. Witiiams, M.D., F.R.S......... 411 Report of the Committee appointed to try Experiments on the Preservation of Animal and Vegetable Substances. Drawn up by the Rev. J. S. Henstow, F.L.S., Professor of Botany in the University: ef Cambridge so. 4 0.0 Soha. 2 eben hae 421 Provisional Reports, and Notices of Progress in Special Researches entrusted to Committees and Individuals OBJECTS AND RULES OF THE ASSOCIATION. OBJECTS. Tue Association contemplates no interference with the ground occupied by other Institutions. Its objects are,—To give a stronger impulse and a more systematic direction to scientific inquiry,—to promote the intercourse of those who cultivate Sci- ence in different parts of the British Empire, with one another, and with foreign philosophers,—to obtain a more general atten- tion to the objects of Science, and a removal of any disadvan- tages of a public kind which impede its progress. RULES. MEMBERS. All Persons who have attended the first Meeting shall be entitled to become Members of the Association, upon subscri- bing an obligation to conform to its Rules. The Fellows and Members of Chartered Literary and Philo- sophical Societies publishing Transactions, in the British Em- pire, shall be entitled, in like manner, to become Members of the Association. The Officers and Members of the Councils, or Managing Committees, of Philosophical Institutions, shall be entitled, in like manner, to become Members of the Association. All Members of a Philosophical Institution recommended by its Council or Managing Committee, shall be entitled, in like manner, to become Members of the Association. Persons not belonging to such Institutions shall be elected by the General Committee or Council, to become Members of the Association, subject to the approval of a General Meeting. SUBSCRIPTIONS. The amount of the Annual Subscription shall be One Pound, to be paid in advance upon admission; and the amount of the composition in lieu thereof, Five Pounds. vi RULES OF THE ASSOCIATION. An admission fee of One Pound is required from all Members elected as Annual Subscribers, after the Meeting of 1839, in addition to their annual subscription of One Pound. Members are entitled to receive copies of any volume of the Transactions for two-thirds of the price at which it is sold to the public ; or by one present payment of Five Pounds, as a fixed Book Subscription, to receive a copy of all the volumes of Transactions published after the date of such payment. Subscriptions shall be received by the Treasurer or Secretaries. If the annual subscription of any Member shall have been in arrear for two years, and shall not be paid on proper notice, he shall cease to be a Member. MEETINGS. The Association shall meet annually, for one week, or longer. The place of each Meeting shall be appointed by the General Committee at the previous Meeting; and the Arrangements for it shall be entrusted to the Officers of the Association. GENERAL COMMITTEE. The General Committee shall sit during the week of the Meeting, or longer, to transact the business of the Association. It shall consist of the following persons : — 1. Presidents and Officers for the present and preceding years, with authors of Reports in the Transactions of the Association. 2. Members who have communicated any Paper to a Philo- sophical Society, which has been printed in its Transactions, and which relates to such subjects as are taken into considera- tion at the Sectional Meetings of the Association. 3. Office-bearers for the time being, or Delegates, altogether not exceeding three in number, from any Philosophical Society publishing Transactions. 4. Office-bearers for the time being, or Delegates, not ex- ceeding three, from Philosophical Institutions established in the place of Meeting, or in any place where the Association has formerly met. 5. Foreigners and other individuals whose assistance is de- sired, and who are specially nominated in writing for the meet- ing of the year by the President and General Secretaries. 6. The Presidents, Vice-Presidents, and Secretaries of the Sections are ex officio members of the General Committee for the time being. SECTIONAL COMMITTEES. The General Committee shall appoint, at each Meeting, Committees, consisting severally of the Members most conver- sant with the several branches of Science, to advise together for the advancement thereof. RULES OF THE ASSOCIATION. vil The Committees shall report what subjects of investigation they would particularly recommend to be prosecuted during the ensuing year, and brought under consideration at the next Meeting. The Committees shall recommend Reports on the state and progress of particular Sciences, to be drawn up from time to time by competent persons, for the information of the Annual Meetings. COMMITTEE OF RECOMMENDATIONS. The General Committee shall appoint at each Meeting a Com- mittee, which shall receive and consider the Recommendations of the Sectional Committees, and report to the General Com- mittee the measures which they would advise to be adopted for the advancement of Science. All Recommendations of Grants of Money, Requests for Special Researches, and Reports on Scientific Subjects, shall be submitted to the Committee of Recommendations, and not taken into consideration by the General Committee, unless previously recommended by the Committee of Recommendations. LOCAL COMMITTEES. Local Committees shall be formed by the Officers of the Asso- ciation to assist in making arrangements for the Meetings. Committees shall have the power of adding to their numbers those Members of the Association whose assistance they may desire. OFFICERS, A President, two or more Vice-Presidents, one or more Se- cretaries, and a Treasurer, shall be annually appointed by the - General Committee. COUNCIL. In the intervals of the Meetings, the affairs of the Association shall be managed by a Council appointed by the General Com- mittee. The Council may also assemble for the despatch of business during the week of the Meeting. PAPERS AND COMMUNICATIONS. The Author of any paper or communication shall be at liberty to reserve his right of property therein. ACCOUNTS. The Accounts of the Association shall be audited annually, by Auditors appointed by the Meeting. vili REPORT—1840. OFFICERS AND COUNCIL, 1840-41. ——E—— Trustees (permunent).—Francis Baily, Esq. R. 1. Murchi- son, Esq. John Taylor, Esq. President.—The Most Noble the Marquis of Breadalbane. Vice-Presidents.—The Very Reverend Principal Macfarlane. Major-Gen. Lord Greenock. Sir David Brewster. Sir Thos. Macdougall Brisbane. President elect.—Rev. Professor Whewell, F.R.S., V.P.G.S. Vice-Presidents elect.—The Earl of Mount Edgcumbe. The Earl of Morley. Lord Eliot, M.P. Sir C. Lemon, Bart., M.P. Sir T. D. Acland, Bart., M.P. General Secretaries.—R. I. Murchison, Esq., F.R.S. Major Sabine, F.R.S. Assistant General Secretary.—John Phillips, Esq., F.R.S., York. Secretaries for the Plymouth, Devonport, and Stonehouse Meeting in 1841.—Wm. Snow Harris, F.R.S. Col. Hamilton Smith, F.L.S. Robert Were Fox, F.R.S. Richard Taylor, jun., Esq. : General Treasurer.—John Taylor, Esq., F.R.S., &c. 2, Duke Street, Adelphi, London. Treasurer to the Meeting in 1841.— Henry Woolcombe, Esq. cil Dr, N. Arnott. R. Brown, Esq. Rev. Dr. Buck- land. J. C. Colquhoun, Esq., M.P. Dr. Daubeny. Sir P. G. Egerton, Bart., M.P. Professor T. Graham. J. EK. Gray, Esq. G. B. Greenough, Esq. W. J. Hamilton, Esq. Dr. Hodgkin. R. Hutton, Esq., M.P. H.B. Jerrard, Esq. C. Lyell, Esq. Professor Miller. Professor Moseley. The Marquis of North- ampton. The Very Rev. Dr. Peacock. E. Pendarves, Esq., M.P. Professor Powell. Lord Sandon, M.P. H. E. Strick- land, Esq. Lieut.-Col. Sykes. H. Fox Talbot, Esq. N. A. Vigors, Esq., M.P. James Walker, Esq. Captain Washing- ton. Professor Wheatstone. Secretary to the Council—James Yates, Esq., F.R.S. 49, Upper Bedford Place, London. Local Treasurers.—Dr. Daubeny, Oxford. Professor Hens- low, Cambridge. Dr. Orpen, Dublin. Charles Forbes, Esq., Edinburgh and Glasgow. William Gray, jun., Esq., York. William Sanders, Esq., Bristol. Samuel Turner, Esq., Liver- pool. Rev. John James Tayler, Manchester. James Russell, Esq., Birmingham. William Hutton, Esq., Newcastle-on- Tyne. Henry Woolcombe, Esq., Plymouth. se eee eeerescesesees ‘Tin “qeg ‘puepy ‘a ‘L ag “bsg “unt ‘ophey, preyory | .......... sees Ory Sue ‘Moma “9 | 44 “SW ‘XOq a0 AA JrIGoOy “S'T'd ‘UUIg uoyrUETy “10D "oH a “bsy ‘sturep] MoUg “UIA, ssccesencevevecseesnssenesssosees «rer faQtir TSI ‘a Ame ‘HooowaTg at haga Bh eal oO” “SUA ‘TTIMAHM YOSSTAOUd “AT OU, See eeererscceee Stesssesseees AayIoyL jo peq auL sev eoeseesesces aqumosp aq qunoy, jo peq ou, : messeecee sess PAT al “a7eg ‘queqstig i “T: ig py a Be ssraseaseaneeareones gmap GOISMOTE PIAVC. AIG . seco eeerrecay® é = ‘bag ‘Teppry Moxpuy US Wad ‘yooussryg poy Terouey-solew *bsq ‘19[8Q 39°T104 "su “bsqy ‘uosSpoyy ydosor "CW ‘aoystye[g u0rkog ‘omy “bsq ‘1axseg 81005 ‘SU “VI ‘Woysuyor tossazorg OFS8T ‘ZT Joquiajdag ‘monsvTy ‘ANVATVGVaUd JO SINDUVIN AHL AIAON LSOW 24L serreeeereoeres guprrepoRyy [edioumg ‘aay £10, ES soe osieniseas sky eis some necrny “bey ‘91109, at seeeaeeeesesses ‘ad “MOSuIqoyy "YL Ap “AOY ouL “6E81 ‘92 IsNSnY ‘WVHONIWUIG ‘V'W ‘INNOOUVH NONYAA “A ‘ADH ONL terrerees TMOMIPA(] JO [IVY OU, treresseeeee TOIdUIeyIION JO Stnbaeypy OI, eecesesese TSW “Ds ‘£q1eg uyor xnvoplig "SOY ‘MOJINTT “UM P07 “SY “JaMoore PY wouI9A “A “AST OUT, ‘om “ST ‘Wosmepy uyor J “WS “Sad ‘ey jo doysig oyy, *joodxaary Someones sancesssseeceee SW TOMO A "M *ADY ‘rouniysuy yedoy ‘soig ‘xexTeA ‘N Ydesor | 's'O a “SW a “Meg ‘uoj103q ger) dityg ig "LES ‘II saquosdag OGgaEADy "bsg ‘aru aovype ay “ULAA [ erettetseeeeesee oar orTO'g ‘moxeq uyor ( ‘uoT ‘ATEN “URYQ “Sod “SL ‘NOLONITYNG JO TUVA CML “CIN ‘WAL tossajorg J" “SOT “S"T'd ‘WotMsion Jo doystg oyy, ee eeeetaseessesses 8CyenTe beg ‘ . . “WapuoAOT “A “A SUd “AW prey *D “f "E81 ‘0g IsNeNY ‘ANAJ-NO-aTESVOMaN, ‘OR “SOU “SU ‘GNVIUAINNHLYON JO TING UL Roper seers cern oir tecvaty ntl SCTE SAAN) ‘OE8I ‘zz 3snsny ‘Toisiug ‘og “SW “CW “Auaqned rossoyorg eRe A eas pee ad ‘09 “SU “'T'O'd ‘ANMOCSNYV JO SINDUVIN OAL OWT ‘pkoyT TOSSOJOIg “AY | eeeetttsteseeses cop Gonty TeMOT AA. “AA AQT "CES ‘OT qsnSny ‘NITEAG “op ‘puejery jo [eAoy “uosy ‘uoyTUMEH “YM IS J “SW “SU ‘UMojUeUIXO JUNODSTA ‘A'TT ‘GAOT LSOAOUd “ATH UL “ASH (099 ‘TOsIqoy UYOL Tig ] ersersssseestseeeees seg ‘TOSUIqO TL ah ‘PEST ‘8 raquiandag § HDYAGNIGT 099 “TY "TSS Wd ‘Seqiog rossagorg J ssstsss**** 029 “Sy | “ajsmarg preg ig f “Gy'T SS’ TOA“ a'0'N ‘INVASINA TVINOGOVIN LAS ‘Wad TTaMoT AA, “AN CAOYE) Lantc ester cee tens Feeececeays a “TOC ‘owed uyor "CORT ‘ez oune ‘TO aIuaNVO 'SO'd “ST “VW ‘Mo[suaxy Iossazorg “soy J ***'029 ‘TeAoy soMOUONsY “S"y'y ‘AUTY "g “YD ‘SOMA “SUA “VIN ‘MOIMDGUS WVGV ‘AT PUL 2” “SYA “VW ‘ea0g rossayorg *Aay | *** ‘00g "[09H “Sarg “O'Y WT ‘TIAMOT AA “AA “AOY ‘CEST ‘61 aun ‘au0rxG 29 “Saad “CW ‘Aueqneg rossajorg f°" "099 “2 TSS ‘TeysMorg preg ag 09 “S'D'd “SW “CC ‘ONVTIMONG “MATH PUL ‘soa “Sua ‘sdtad pe ae ee a BO wad { "LEST ‘2% requiaidag ‘au0X ‘gyrg Cunt erg wenn, [SOAS Wa VW Fmoorey WOUII A” AA *AOY 08 “SOE “Sd “TOG WVITIMZLIA HVE UL *SOLIVJIAIIGG [vIO"y *sqUOpIsarg-201A4 *squepIsoig *JUIUIIDUIUIMNOD S}I WOT ‘SoLe}aIIIG 90] pur ‘syuapiserg-a01, ‘syuapIsarg Yy1M ‘UoIyeLOOssy YsHiig, ay} Jo 3 Sayja2qql JO soul], pue soovq oy} Surmoys oqey, “[ . eT 78. 2) x REPORT—1840. II. Table showing the Members of Council of the British Association from its Commencement, in addition to Presidents, Vice-Presidents, and Local Secretaries. Rev. Wm. Vernon Harcourt, F.R.S., &c. 1832—1836. [ Francis Baily, V.P. and Treas. R.S. ......1835. R. I. Murchison, F.R.S., F.G.S. .......- 1836—1840. Rev. G. Peacock, F.R.S., F.G.S., &c. ...1887, 1838. Major Sabine, V.P.R.S. .......0eeeseeeeeeee 1839, 1840. General Treasurer. John Taylor, F.R.S., Treas. G.S., &c. ...1832—1839. Charles Babbage, F.R.SS.L. & E., &c. (Resigned.) T, R. I. Murchison, F.R.S., &c. rustees(permanent).. John Taylor, F.B-S., &c. Francis Baily, F.R.S. General Secretaries. Se ehay | } Professor Phillips, RS, Be. --..-¢c10. 1832—1839. ecretary. Members of Council. G. B. Airy, F.R.S., Astronomer Royal ...... 1834, 1835. Wewl Arnott M.D. od edccssasecidesseoes 1838, 1839, 1840. Francis Baily, V.P. and Treas. R.S. ......... 1837—1839. George Bentham, F.L.S. .......0csscccsesseeeees 1834, 1835. Robert Brown, D.C.L., F.R.S. .....ceseeeeees 1832, 1834, 1835, 1838-1840. Sir David Brewster, F.R.S., &C. .....seceeseeee 1832. M. I. Brunel, F.R.S., &c. ...csseeeees Bvcecaetn 1832. Rev. Professor Buckland, D.D., F.R.S., &c. .1833, 1835, 1838, 1839, 1840. The Earl of Burlington .........:.ceeseseeeees 1838, 1839. Rev. T. Chalmers, D.D., Prof. of tele pee Mdinbure bh tersescecedsstecsssessateresessse> Professor Clark, Cambridoeiiics.9...50css0.0~ 5 fa Professor Christie, ORGS i: Q0C! neces sceeses Sones 1838—1837. William Clift, F.R.S., F.G.S. ........ceseeseees 1832—1835. J.C. Colquhoun, Esq., M.P. .........0000 -- 1840. John Corrie, F.R.S., &. ..ccsceeeeeeeeeees ae 1832. Professor Daniell, F.R.S. .........cccceeeeseeeees 1836, 1839. ID ie) DERM SET foenececeAaoout jon s= ceenoonannececce 1838, 1839, 1840. Jepte WVINK WALL jon cecclescacasedesscwisacessoese. 1834, 1835. Sir P. G. Egerton, Bart., M. :P.. 1840. The Ear! Fitzwilliam, D.C Ss F. R.S. S "&c....1833. Professor Forbes, F. R. Ss. Le rd OA ae 1832. Davies Gilbert, D.C.L., V.P.R.S., &. ...... 1832. Professor R. Graham, M.D., F.R.S.E......00. 1837. Professor Thomas Graha ay ERS ee 1838, 1839, 1840. John Edward Gray, F.R.S., F.L.S., &c....... 1837—1839, 1840 Professor Green, F.R. s. gv Ge St teccasei reece 1832, G. B. Greenough, F.R.S., F.G.S. .....s0eeee 1832—1839, 1840. Henry Hallam, F.R.S., F.S.A., Sie. weee 1836, Sir William R. Hamilton, Astron. Royal of Nirelandine sa, 2ects.seeces cocscte naceadaectee ..1832, 1833, 1836. W. J. Hamilton, See. GiSi vet a séssebenwenoeen 1840. Rev. Prof. Henslow, M.A., F.L.S., Ee S....1837. Sir John F. W. Herschel, P. R.SS. L. & E., F.R.A.S., F.G.S., ASE, sata see 1832. Thomas Hodgkin, M.D. Sane csderesgcensesteceee 1833—1837, 1839, 1840. Prof. Sir W. J. Hooker, LL.D., FR. S., &e. .1832. MEMBERS OF COUNCIL. x1 Rey. F. W. Hope, M.A., F.L.S.........000000+ 1837. Robert Hutton, M.P., F.G.S., &c. ............1836, 1838, 1839, 1840. Professor R. Jameson, F.R.SS. L. & E....... 1833. Rev. Leonard Jenyns) .. ........sseceeseeeceeeee 1838. H. B. Jerrard, Esq. ...c000...ccsesceeeeesecosnes 1840. ermine GCE. cecasredaccctctescacanssseresscesaeaane 1839, Sir C. Lemon, Bart., M.P. ......... eeueeicase 1838, 1839. Hiewa Dr wMavdner...;sccescasscavcccccocweccsdaews 1838, 1839. Professor Lindley, F.R.S., F.L.S., &c. ......1833, 1836. Rev. Professor Lloyd, D.D.............s.ses0e0 1832, 1833. J. W. Lubbock, F.R.S., F.L.S., &c., Vice- Chancellor of the University of London 1833—1836, 1838, 1839. Rev. Thomas Luby .0......sseeceeeveres Saesac 1832. Charles Lyell, jun., FLR.S. ........ceseeseeeeees 1838, 1839, 1840. William Sharp MacLeay, F.L.S............. ... 1837. Professor Miller, F.G.S..........ssceeeeeeees wees 1840. Professor Moseley ........sessesesseeseescseneesees 1839, 1840, Patrick Neill, LL.D., F.R. a ae oeegsee 1833. The Marquis of Northampton, ERS. endaactns 1840. Richard Owen, F.R.S., F.L.S. ...... .....00 ....1836, 1838, 1839. Rev. George Peacock, M.A., F.R.S., &c......1832, 1834, 1835, 1839, 1840. E. Pendarves, Esq., M.P........ss-sesesecseeseeees 1840. Rev. Professor Powell, M.A., F.R.S., &c...... 1836, 1837, 1839, 1840. J.C. Prichard, M.D., F.R.S., &c....ccccescecees 1832. George Rennie, F.R.S. .cs.ccesecececscscscecsaees 1833—1835, 1839. Sir John Rennie...........02+000+ Sb haee a Ay die 1838. Rev. Professor Ritchie, F.R.S. ..........ceceeeee 1833. Sir John Robison, Sec. R.S.E, .........eceeeeeee 1832, 1836. P. M. Roget, M.D., Sec. R.S., F.G.S., &c....1884—1837. Major Sabine ...........c00. ecedaeg macs vend “SeAHeee 1838. Bord Sandon, M PY c.5cansesecsncceceesosnvescessoes 1840. Rev. William Scoresby, B.D., F.R.SS. L. & E.1832. H. E. Strickland, Esq., F.G. BRO... teal 1840. Lieut.-Col. W. H. Sykes, F.R.S., F.L.S., &e. 1837—1839, 1840. H. Fox Talbot, Esq., F.R.S. .......ececeeeneceeese 1840. Rev. J. J. Tayler, B.A., Manchester............ 1832. Professor Traill, M.D. ...... ata Mae See son Boe oe 1832, 1833. N. A. Vigors, M.P., D.C.L., F.S.A., F.L.S.. 1832, 1836, 1840. James Walker, Esq., P.S.C. a aa a 1840. Captain Washington, GANG Beecwratans tes sp sansa .. 1838, 1839, 1840. Professor Wheatstone ......s+-ss+ceccseeesseeoneee 1838, 1839, 1840. Rev. W.. Whewell..2: cbata.tho.o,de ls ieteh sacotecee 1838, 1839. William Yarrell, F.L.S. scsccescsccscccscceeceeen 1833-1836. Secretaries to the { Edward esd M.D. ae F.R.SS. L. & E.1832—1836. Council. James Yates, F.R.S., F.L.S., F.G.S. 1831—1840. xil REPORT—1840. OFFICERS OF SECTIONAL COMMITTEES AT THE GLASGOW MEETING. SECTION A.—MATHEMATICAL AND PHYSICAL SCIENCE. President.—Professor Forbes, F.R.S. Vice-Presidents.—G. B. Airy, Esq., F.R.S., Astron. Royal. Rev. Professor Whewell, F.R.S. Professor James Thomson, LL.D. Secretaries.—Professor Stevelly. Rey. Dr. Forbes, F.R.S. Arch. Smith, Esq. SECTION B.—CHEMISTRY AND MINERALOGY. President.—Dr. Thomas Thomson, F.R.S. Vice-Presidents.—Professor Thomas Graham, F.R.S. _ Pro- fessor Johnston, F.R.S. Secretaries.—Dr. R. D. Thomson. Dr. Thomas Clark. Dr. L. Playfair. SECTION C.—GEOLOGY AND PHYSICAL GEOGRAPHY. President for Geology.—Charles Lyell, Esq., F.R.S. President for Physical Geography.—G. B. Greenough, Esq., F.R.S. Vice- Presidents.—Rev. Professor Buckland, F.R.S. H. T. De la Beche, Esq., F.R.S. James Smith, Esq., F.R.S. Capt. Washington, R.N. Secretaries. —W. J. Hamilton, Esq., F.R.S. H. E. Strick- land, Fisq., F.G.S. D. Milne, Esq., F.G.S. John Scoular, Esq., M.D. Hugh Murray, Esq., F.R.S.E. SECTION D.—ZOOLOGY AND BOTANY. President.—Sir W. J. Hooker, LL.D. Vice-Presidents.—The Rev. Professor Fleming, D.D. Sir William Jardine, Bart. Professor Graham, F.R.S.E. P. J. Selby, Esq., F.L.S. Secretaries.—Professor William Couper. Robert Paterson, Esq. Edward Forbes, Esq., M.W.S. SECTION E.—MEDICAL SCIENCE. President.—James Watson, Esq., M.D. Vice-Presidents.—J. Hodgkin, Esq., M.D. Dr. Andrew Buchanan. Dr. John M‘Farlane. Secretaries.—Professor Couper. Dr. James Brown. Pro- fessor Reid. OFFICERS OF SECTIONAL COMMITTEES. Xili SECTION F.—STATISTICS. President.—Lord Sandon, F.R.S., M.P. Vice- Presidents.—Mr. Sheriff Alison. Rev. Dr. Chalmers. Lieutenant-Colonel Sykes, F.R.S. Secretaries.—Professor Ramsay. R.W. Rawson, Esq. Charles R. Baird, Esq. SECTION G.—MECHANICAL SCIENCE. President.—Sir John Robison, Sec. R.S. Edin. Vice-Presidents.—His Grace the Duke of Argyll. The Rev. T. R. Robinson, D.D. John Taylor, Esq., Treas. B.A. James Walker, Esq., Pres. Inst. Civ. Eng. Secretaries.—J. Scott Russell, Esq. Charles Vignoles, Esq., C.E. James Thompson, Esq., C.E. James Tod, Esq., Sec. Soc. of Arts. CORRESPONDING MEMBERS. Professor Agassiz, Neufchatel. M. Arago, Secretary of the Institute, Paris. A. Bache, Principal of Girard College, Phi- ladelphia. Professor Berzelius, Stockholm. Professor De la Rive, Geneva. Professor Dumas, Paris. Professor Ehrenberg, Berlin. Professor Encke, Berlin. Baron Alexander von Hum- boldt, Berlin. M. Jacobi, St. Petersburgh. Professor Liebig, Giessen. Professor Link, Berlin. Professor Girsted, Copen- hagen. M. Otto, Breslau. Jean Plana, Astronomer Royal, Turin. M. Quetelet, Brussels. Professor Schumacher, Altona. BRITISH ASSOCIATION FOR THE ~ SS SS eee eae TREASURER’S ACCOUNT from RECEIPTS. 3 GSopaniae ete, o:. a Balance in hand from last year’s ACCOUNT ......scssesseeseeeeeers 460 13 4 Compositions from Members at the Birmingham Meetin and el duet dann. Lk.can co recevecasee aC one Subscriptions, 1839. ........ccccccccscecsscvecsessescscscnceeerescosces 1023 1 0 Ditto MRA erctemccsseses dak n2 cova doncadesewasesseacaaces 20 0 DItLOPNTN CATH ECO crcagearedsedress:occcccsrcucdsssciarpecserastes ia. Oo x — 1555 2,0 ividend on £5500 in 3 per cent. consols, 6 months to ee ealie eeer eere eee) steeeurs. itr satay’ Ditto £5000 ditto 6 months to July last 75 0 0 157 10 0 Received on account of Sale of Reports, viz. Ist Vol., 2nd. Edition ...:c0sscsercseccececscrcecennses 1614 0 Pru Oliaseriaceusiots oss: scsntaesrteesasaveddes dees paane s 1216 0 BEGUN Olea noxcsstes sede custacgh eons tsoas osneas sadee weston Papal AK aa ADI WOlewweneavsroncetcadagenscodetsneasvecersurscersaeess 26 2 0 Ebb) ivOlesiacacas'ep ence cacddanwammeneercerederacssteaatmere 27 4 0 Gtilt WO)-ccous accccacdccnsscentcdevscacessscéessosarsn . 83 6 O AULD VO): dccocseccesoseccesetnestecass see ssuesasde mec swenss 160 15 0 344 7 0 Lithographs sold.......... sodbh ae lviachbeuspacietes MANERA 110 0 MPublin, Report Sold ssa.ctsesseaesaset csv estemeen te scsena da ccsentsesestes 0 2 3 Compositions for future publications........scseresssesescecereresess 75 0 0 Sale of £500 3 per cent. consols ...... Peete Pas rarccnnveen? iwesesoas 460 13 6 i £3054 18 1 W.H. SYKES, LEONARD HORNER, }AvpiTors. WILLIAM YARRELL, ——- ADVANCEMENT OF SCIENCE. 16th AucusT 1839 to the 3lst Aucust 1840. PAYMENTS. & 3. d. £ os. d. Expenses of Meeting at Birmingham.............sssescsscesseeerees 250 0 0 Disbursements by General and Local Treasurers.........+0s0e00 103 11 #1 Salaries to Assistant Secretary, Accountant and Clerk .......... 247 10 0 Grants to Committees for Scientific purposes, viz. for Reduction of Stars in Histoire Céleste ........sssccecssceersncees 242 10 O Do. do. Lacaille.........s.scsceceseeeeeene 415 0 Catalogue emi ck intestine dena ate one scacaccaanorcectennce cates 264 0 0 Tides’ Discussions at Bristol, 1838. ..........cssccecscoeceee .-. 100 0 0 Do. dO. ....00e Sarecennatecene ces saviah sn Sean eases . 50 0 0 Subterranean Temperature.......ssseccsscesscccssssssccesceeseeees . 1818 6 Land and Sea Level ......... 1838. 611 1 Atmospheric Air...... Shes sane Roa cnea rece necats econwceacees set ece eat 1515 0 Action of Water on Iron .........00008 . 10 0 0 Do on Organic matter 7 0 0 Foreign Scientific Memoirs, 1838. ............ £100 0 et 11216 Do. do. VSBOl + x esses 12 1 6 Working Population, Le aye ee CERO AME Aa Sea San ee ees 100 0 0 School Statistics, USSG doe cvcaceevatexe dons: ugveoncscact 50 0 0 Forms of Vessels, WSS rescerscsccceresteveaceeeee vacryas 184 7 O Meteorological Observations at Plymouth ..........csseseeeees 40 0 0 Mr. Osler’s Anemometer Ot Mes ciedees ste .. 380 0 0 Professor Whewell’s do. (OS Sad An nee caseenoatecatnedigny 10 0 0 Meteorological Observations in Scotland (Hourly) sees 5217 6 Magnetical Observations (Instruments) ..........0.sesseseeenes 185 13 9 Chemical and Electrical Phenomena —.............seceeeereeees 40 9 0 Experiments on the Heart ..........cssssscescscceceecscsecsecsceees 18 19 0 Do. TSH Sh a wsalesachesdasscstcenest eds scscoraces shee 813 0 Reduction of Meteorological Observations ........0...ssssevees 18 0 1548 4 4 Paid for Printing Reports, 7th vol............cseseees per ceeen sehen eat 447 15 0 _ Do. Engraving for RUS Wiest aee vacate des fens chat sineni-ncieuteak 74:4 6 —— 52119 6 Printing List of Members .............cssesseccnsccsccsscensccescens 31 0 2 Do. and Advertising, &C..........ccsscsscsseceecceccesenssavaseces 20 9 6 Sundry Expenses in Publishing Reports .........ccssecsessereeeens 22 12 0 Balance in hands of Bankers..........sscescsseesseneers ease ca 205 17 0 Do. Treasurer and Local Treasurers ...... 103 14 6 — 309 11 6 £3054 18 1 ——— ae xvi REPORT—1840. The following Reports on the Progress and Desiderata of dif- ferent branches of Science have been drawn up at the request of the Association, and printed in its Transactions. ° 1831-32. On the progress of Astronomy during the present century, by G. B. Airy, M.A., Astronomer Royal. On the state of our knowledge respecting Tides, by J. W. Lubbock, M.A., Vice-President of the Royal Society. On the recent progress and present state of Meteorology, by James D. Forbes, F.R.S., Professor of Natural Philosophy, Edinburgh. On the present state of our knowledge of the Science of Ra- diant Heat, by the Rev. Baden Powell, M.A., F.R.S., Savilian Professor of Geometry, Oxford. On Thermo-electricity, by the Rev. James Cumming, M.A.., F.R.S., Professor of Chemistry, Cambridge. On the recent progress of Optics, by Sir David Brewster, K.C.G., LL.D., F.R.S., &c. On the recent progress and present state of Mineralogy, by the Rev. William Whewell, M.A., F.R.S, On the progress, actual state, and ulterior prospects of Geology, by the Rev. William Conybeare, M.A., F.R.S., V.P.G.S., &c. Onthe recent progress and present state of Chemical Science, by J. F. W. Johnston, A.M., Professor of Chemistry, Durham. On the application of Philological and Physical researches to the History of the Human species, by J. C. Prichard, M.D., F.R.S., &c. 1833. On the advances which have recently been made in certain branches of Analysis, bythe Rev. G. Peacock, M.A.,F.R.S., &c. Onthe present state of the Analytical Theory of Hydrostatics and Hydrodynamics, by the Rev. John Challis, M.A., F.R.S.,&c. On the state of our knowledge of Hydraulics, considered as a branch of Engineering, by George Rennie, F.R.S., &c. (Parts I. and II.) On the state of our knowledge respecting the Magnetism of the Earth, by S. H. Christie, M.A., F.R.S., Professor of Ma- thematics, Woolwich. On the state of our knowledge of the Strength of Materials, by Peter Barlow, F.R.S. On the state of our knowledge respecting Mineral Veins, by John Taylor, F.R.S., Treasurer G.S., &c. On the state of the Physiology of the Nervous System, by William Charles Henry, M.D RESEARCHES IN SCIENCE. XVii Onthe recent progress of Physiological Botany, by John Lind- ley, F.R.S., Professor of Botany in the University of London. 1834. On the Geology of North America, by H. D. Rogers, F.G.S. On the philosophy of Contagion, by W. Henry, M.D.,F.R.S. On the state of Physiological Knowledge, by the Rev. Wm. Clark, M.D., F.G.S., Professor of Anatomy, Cambridge. On the state and progress of Zoology, by the Rev. Leonard Jenyns, M.A., F.L.S., &c. On the theories of Capillary Attraction, and of the Propaga- tion of Sound as affected by the Development of Heat, by the Rev. John Challis, M.A., F.R.S., &c. On the state of the science of Physical Optics, by the Rev. H. Lloyd, M.A., Professor of Natural Philosophy, Dublin. 1835. On the state of our knowledge respecting the application of Mathematical and Dynamical principles to Magnetism, Electri- city, Heat, &c., by the Rev. Wm. Whewell, M.A., F.R.S. On Hansteen’s researches in Magnetism, by Captain Sabine, F.R.S. On the state of Mathematical and Physical Science in Bel- gium, by M. Quetelet, Director of the Observatory, Brussels. 1836. On the present state of our knowledge with respect to Mine- ral and Thermal Waters, by Charles Daubeny, M.D., F.R.S., M.R.1.A., &c., Professor of Chemistry and of Botany, Oxford. On North American Zoology, by John Richardson, M.D., F.R.S., &c. ; Supplementary Report on the Mathematical Theory of Fluids, by the Rev. J. Challis, Plumian Professor of Astronomy in the University of Cambridge. 1837. On the variations of the Magnetic Intensity observed at dif- ferent points of the Earth’s Surface, by Major Edward Sabine, R.A., F.R.S. On the various modes of Printing for the use of the Blind, by the Rev. William Taylor, F.R.S On the present state of our knowledge in regard to Dimor- phous Bodies, by Professor Johnston, F.R.S. On the Statistics of the Four Collectorates of Dukhun, under the British Government, by Col. Sykes, F.R.S. 1838. Appendix to Report on the variations of Magnetic Intensity, by Major Edward Sabine, R.A., F.R.S. 1840. b XVlii REPORT—1840. 1839. Report on the present state of our knowledge of Refractive Indices for the Standard Rays of the Solar Spectrum in dif- ferent media, by the Rev. Baden Powell, M.A., F.R.S., F.G.S., F.R.Ast.S., Savilian Professor of Geometry, Oxford. Report on the distribution of Pulmoniferous Mollusca in the British Isles, by Edward Forbes, M.W.S., For. Sec. B.S. 1840. Report on the recent progress of discovery relative to Radiant Heat, supplementary to a former Report on the same subject inserted in the first volume of the Reports of the British Asso- ciation for the Advancement of Science, by the Rev. Baden Powell, M.A., F.R.S., F.R.Ast.S., F.G.S., Savilian Professor of Geometry in the University of Oxford. Supplementary Report on Meteorology, by James D. Forbes, Esq., F.R.S., Sec. R.S. Ed., Professor of Natural Philosophy in the University of Edinburgh. —— —____—. The following Reports of Researches undertaken at the request of the Association have been published, viz. 1835. On the comparative measurement of the Aberdeen Standard Scale, by Francis Baily, Treasurer R.S., &c. On Impact upon Beams, by Eaton Hodgkinson. Observations on the Direction and Intensity of the Terrestrial Magnetic Force in Ireland, by the Rev. H. Lloyd, Capt. Sabine, and Capt. J. C. Ross. On the Phenomena usually referred to the Radiation of Heat, by H. Hudson, M.D. Experiments on Rain at different Elevations, by Wm. Gray, jun., and Professor Phillips. Hourly observations of the Thermometer at Plymouth, by W.S. Harris. On the Infra-orbital Cavities in Deers and Antelopes, by A. Jacob, M.D. On the Effects of Acrid Poisons, by T. Hodgkin, M.D. On the Motions and Sounds of the Heart, by the Dublin Sub-Committee. On the Registration of Deaths, by the Edinburgh Sub- Committee. 1836. Observations on the Direction and Intensity of the Terres- RESEARCHES IN SCIENCE. XIx trial Magnetic Force in Scotland, by Major Edward Sabine, R.A., F.R.S., &c. Comparative view of the more remarkable Plants which cha- racterize the Neighbourhood of Dublin, the Neighbourhood of Edinburgh, and the South-west of Scotland, &c.; drawn up for the British Association by J.T. Mackay, M.R.LA., A.L.S., &c., assisted by Robert Graham, Esq., M.D., Professor of Botany in the University of Edinburgh. Report of the London Sub-Committee of the Medical Section of the British Association on the Motions and Sounds of the Heart. Second Report of the Dublin Sub-Committee on the Motions and Sounds of the Heart. Report of the Dublin Committee on the Pathology of the Brain and Nervous System. Account of the Recent Discussions of Observations of the Tides which have been obtained by means of the grant of money which was placed at the disposal of the Author for that purpose at the last Meeting of the Association, by J. W. Lubbock, Esq. Observations for determining the Refractive Indices for the Standard Rays of the Solar Spectrum in various media, by the Rev. Baden Powell, M.A., F.R.S., Savilian Professor of Geo- metry in the University of Oxford. Provisional Report on the Communication between the Arte- ries and Absorbents, on the part of the London Committee, by Dr. Hodgkin. Report of Experiments on Subterranean Temperature, under the direction of a Committee, consisting of Professor Forbes, Mr. W.S. Harris, Professor Powell, Lieut.-Colonel Sykes, and Professor Phillips (Reporter). Inquiry into the validity of a method recently proposed by George B. Jerrard, Esq., for Transforming and Resolving Equations of Elevated Degrees; undertaken, at the request of the Association, by Professor Sir W. R. Hamilton. 1837. Account of the Discussions of Observations of the Tides - which have been obtained by means of the grant of money which was placed at the disposal of the Author for that purpose at the last Meeting of the Association, by J. W. Lubbock, Esq., E.R.S. ; On the difference between the Composition of Cast Iron produced by the Cold and the Hot Blast, by Thomas Thomson, M.D., F.R.SS. L. & E., &c., Professor of Chemistry, Glasgow. On the Determination of the Constant of Nutation by the ~ XX REPORT—1840. Greenwich Observations, made as commanded by the British Association, by the Rev. T. R. Robinson, D.D. On some Experiments on the Electricity of Metallic Veins, and the Temperature of Mines, by Robert Were Fox. Provisional Report of the Committee of the Medical Section of the British Association, appointed to investigate the Com- position of Secretions, and the Organs producing them. Report from the Committee for inquiring into the Analysis of 7 Glands, &c. of the Human Body, by G. O. Rees, M.D., aG.8. Second Report of the London Sub-Committee of the British Association Medical Section, on the Motions and Sounds of the Heart. Report from the Committee for making experiments on the Growth of Plants under Glass, and without any free communi- cation with the outward air, on the plan of Mr. N. I. Ward, of London. Report of the Committee on Waves, appointed by the British Association at Bristol in 1836, and consisting of Sir John Robi- son, K.H., Secretary of the Royal Society of Edinburgh, and John Scott Russell, Esq., M.A., F.R.S. Edin. (Reporter). On the relative Strength and other mechanical Properties of Cast Iron obtained by Hot and Cold Blast, by Eaton Hodgkinson, Esq. On the Strength and other Properties of Iron obtained from the Hot and Cold Blast, by W. Fairbairn, Esq. 1838. Account of a Level Line, measured from the Bristol Channel to the English Channel, during the Year 1837-38, by Mr. Bunt, under the Direction of a Committee of the British As- sociation. Drawn up by the Rev. W. Whewell, F.R.S., one of the Committee. A Memoir on the Magnetic Isoclinal and Isodynamic Lines in the British Islands, from Observations by Professors Hum- phrey Lloyd and John Phillips, Robert Were Fox, Esq., Cap- tain James Clark Ross, R.N., and Major Edward Sabine, R.A., by Major Edward Sabine, R.A., F.R.S. First Report on the Determination of the Mean Numerical Values of Railway Constants, by Dionysius Lardner, LL.D., FE.R.S., &c. First Report upon Experiments, instituted at the request of the British Association, upon the Action of Sea and River Water, whether clear or foul, and at various temperatures, upon Cast and Wrought Iron, by Robert Mallet, M.R.I.A., Ass. Ins. C.E. RE SEARCHES IN SCIENCE. Xxi Notice of Experiments in progress, at the desire of the British Association, on the Action of a Heat of 212° Fahr., when long continued, on Inorganic and Organic Substances, by Robert Mallet, M.R.I.A. Experiments on the ultimate Transverse Strength of Cast Iron made at Arigna Works, Co. Leitrim, Ireland, at Messrs. Bramah and Robinson’s, 29th May, 1837. Provisional Reports, and Notices of Progress in Special Re- searches entrusted to Committees and Individuals. 1839. _ Report on the application of the sum assigned for Tide Calcula- tions to Mr. Whewell, ina Letter from T. G. Bunt, Esq., Bristol. Notice of Determination of the Arc of Longitude between the Observatories of Armagh and Dublin, by the Rev. T. R. Robinson, D.D., &c. Report of some Galvanic Experiments to determine the existence or non-existence of Electrical Currents among Stra- tified Rocks, particularly those of the Mountain Limestone formation, constituting the Lead Measures of Alston Moor, by H. L. Pattinson, Esq. Report respecting the two series of Hourly Meteorological Observations kept in Scotland at the expense of the British Association, by Sir David Brewster, K.H., LL.D., F.R.SS. L. and E. Report on the subject of a series of Resolutions adopted by the British Association at their Meeting in August 1838, at Newcastle. Report on British Fossil Reptiles, by Richard Owen, Esq., F.R.S., F.G.S., &c. Third Report on the Progress of the Hourly Meteorological Register at the Plymouth Dock-yard, Devonport, by W. Snow Harris, Esq., F.R.S. 1840. Report on Professor Whewell’s Anemometer, now in opera- tion at Plymouth, by W. Snow Harris, Esq., F.R.S., &c. Report on the Motions and Sounds of the Heart, by the London Committee of the British Association for 1839-40. An Account of Researches in Electro-Chemistry, by Pro- fessor Schénbein, of Basle. Second Report upon the Action of Air and Water, whether fresh or salt, clear or foul, and at various temperatures, upon Cast Iron, Wrought Iron, and Steel, by Robert Mallet, M.R.I.A., Ass. Ins. C.E. Report on the Observations recorded during the Years 1837, Xxil REPORT— 1840. 1838, 1839, and 1840, by the Self-registering Anemometer erected at the Philosophical Institution, Birmingham. By A. Follett Osler, Esq. Report respecting the two series of Hourly Meteorological Observations kept at Inverness and Kingussie, at the Expense of the British Association, from Nov. Ist, 1838, to Nov. 1st, 1839. By Sir David Brewster, K.H., F.R.S., &c. Report on the Fauna of Ireland: Div. Vertebrata. Drawn up, at the request of the British Association, by William Thomp- son, Esq. (Vice-Pres. Nat. Hist. Society of Belfast), one of the Committee appointed for that purpose. Report of Experiments on the Physiology of the Lungs and Air-tubes. By Charles J. B. Williams, M.D., F.R.S. Report of the Committee appointed to try Experiments on the Preservation of Animal and Vegetable Substances. By the Rey. J. S. Henslow, F.L.S. The following Reports and Continuations of Reports have been undertaken to be drawn up at the request of the Association. On Salts, by Professor Graham, F.R.S. On the Differential and Integral Calculus, by the Rev. Pro- fessor Peacock, M.A., F.R.S., &c. On the Geology of North America, by H. D. Rogers, F.G.S., Professor of Geology, Philadelphia. On Vision, by Professor C. Wheatstone, F.R.S. On the application of a General Principle in Dynamics to the Theory of the Moon, by Professor Sir W. Hamilton. On Isomeric Bodies, by Professor Liebig. On Organic Chemistry, by Professor Liebig. On Inorganic Chemistry, by Professor Johnston, F.R.S. On Fossil Reptiles (continuation), by Professor Owen, F.R.S. On the Salmonide of Scotland, by Sir W. Jardine. On the Caprimulgide, by N. Gould, F.L.S. On the state of Meteorology in the United States of North America, by A. Bache. On the state of Chemistry as bearing on Geology, by Pro- fessor Johnston. On Molluscous Animals:and their Shells, by J. E. Gray, F.R.S. On Ornithology, by P. J. Selby, F.R.S.E. On the Specific Gravity of Steam, by a Committee, of which Mr. B. Donkin is Secretary. On the Temperature of the deep Mines of Cornwall, from his own observations, by W. J. Henwood, F.G.S. RESEARCHES IN SCIENCE. XXlil On the recent progress and present condition of Electro- Chemistry and Electro-Magnetism, by Professor de la Rive, of Geneva. ; Recommendations for Additional Reports and Researches in Science adopted by the General Committee ut the Glasgow Meeting. ADDITIONAL REPORTS ON THE STATE OF SCIENCE REQUESTED. Resolved— That Professor Airy be requested to furnish a second Report on the progress of Astronomy during the present century. The date of the former Report, presented by Professor Airy, is 1831-32. That a Committee, consisting of the Astronomer Royal, Professor Lloyd, Major Sabine, and Professor Phillips, be appointed to report on the publication or other disposal of Hourly Meteorological Observations now in possession of the Association. : The Report to be presented at the next meeting of the As- sociation. That Professor Willis be requested to furnish the Report on the state of our knowledge of the Phenomena of Sound, for- merly requested. The Report to be presented at the next meeting of the As- sociation. That Dr. Peacock be requested to furnish the Report on the Differential and Integral Calculus, formerly requested. The Report to be presented at the next meeting of the As- sociation. That Professor Wheatstone be requested to furnish the Re- port on Vision, formerly requested. The Report to be presented at the next meeting of the As- sociation. That Professor Sir W. Hamilton be requested to furnish the Report on the application of a General Principle in Dynamics to the Theory of the Moon, formerly requested. The Report to be presented at the next Meeting of the As- sociation. That Professor Kelland be requested to draw up a Report on XXIV REPORT—1840. the History and present state of the Theory of the Undulations of Fluid and Elastic Media. The Report to be presented at the next meeting of the As- sociation. That Professor Kelland be requested to furnish a Report on the relative state of our experimental and mathematical know- ledge on the subject of the Conduction of Heat; to point out ‘the experiments already made which require repetition, and those which are necessary to complete the comparison of Theory and Experiment. The Report to be presented at the next meeting of the As- sociation. That Professor Bache be requested to furnish his Report on the Meteorology of the United States for the next meeting of the Association. That a Committee, consisting of Mr. Lubbock, Sir J. W. Herschel, Dr. Robinson, Professor Forbes, Professor Whewell, Professor Miller, Sir David Brewster, and Major Sabine, be requested to report to the Association how far the Desiderata in our knowledge of the condition of the upper strata of the Atmosphere may be supplied by means of ascents in balloons or otherwise ; to ascertain the probable expense of such experi- ments, and draw up directions for observers in such circum- stances. The Report to be presented at the next meeting of the As- sociation. That Professor Johnston be requested to furnish the Report on Inorganic Chemistry, formerly requested. That Professor de la Rive, of Geneva, be requested to furnish the Report on the recent progress and present condition of Electro-Chemistry and Electro-Magnetism, formerly re- quested. The Report to be presented at the next meeting of the As- sociation. That Professor Johnston be requested to continue his re- searches upon Chemical Geology, and to direct his attention particularly to the effects of igneous rocks. That Dr. Daubeny be requested to prepare a Report on the connexion of Chemistry and Agriculture, formerly requested. RESEARCHES IN SCIENCE. XXV That Sir John Graham Dalyell be requested to prepare a Report on the habits of the Radiate Animals. That the following be a Committee to inquire into and report on the experiments made by Mr. C. W. Williams, of Liverpool, on the Combustion of Coal and other Fuels, with the view of obtaining from them the greatest ‘calorific effect, and avoiding the generation of smoke, viz. Mr. Vignoles, Mr. Fairbairn, Mr. Grantham, and Mr. Spence. That Mr. Hodgkinson be requested to complete his experi- ments on the resistance of the Atmosphere to Moving Bodies, and to report the result to the next meeting of the British Association. That the following be a Committee to make experiments for ascertaining the comparative efficiency of the Turbine and Common Water Wheels, and to report at the next meeting :— Mr. Smith, of Deanston, Professor Gordon, Mr. W. Fairbairn. Recommendations of Researches in Science involving Grants of Money for Scientific Purposes, adopted by the General Committee at the Glasgow Meeting. Resolved— That Sir D. Brewster and Professor Forbes be requested to revise and continue the Hourly Observations at Inverness and Kingussie, and that a sum not exceeding 85/. be placed at their disposal for the purpose. That a Committee, consisting of Professor Whewell, be re- quested to superintend calculations on the Tides at Leith b Mr. D. Ross, and that the sum of 50/. be placed at the dis- posal of Professor Whewell for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Professor Whewell, be re- quested to superintend calculations on Tides at Bristol by Mr. Bunt, and that the sum of 50/. be placed at the disposal of Professor Whewell for the purpose. The Report to be presented at the next meeting of the As- - sociation. That Major Sabine be requested to provide a good mountain XXV1 REPORT—1840. barometer and a thermometer for the assistance of Mr. M‘Cord in his Meteorological Observations, the sum of 201. to be placed at the disposal of Major Sabine for the purpose. The Report to be presented at the next meeting of the As- sociation. That the grant of 100/. for the reduction of Meteorological Observations, under the superintendence of Sir J. Herschel, be continued. The Report to be presented at the next meeting of the As- sociation. That the Committee already appointed for the revision of the Nomenclature of Stars, consisting of Sir John Herschel, Mr. Whewell, and Mr. Baily, be re-appointed, and that the sum of 500. be placed at the disposal of the Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That the Committee already appointed for the reduction of the Stars in the Histoire Céleste, consisting of Mr. Baily, the Astronomer Royal, and Dr. Robinson, be re-appointed, and that the sum of 150/. be placed at the disposal of the Com- mittee for the purpose. The Report to be presented at the next meeting of the As- sociation. That the Committee already appointed to extend the Royal Astronomical Society’s Catalogue, consisting of Mr. Baily, the Astronomer Royal, and Dr. Robinson, be re-appointed on the condition originally stipulated, that the Catalogue be called the British Association Catalogue, and that 150/. be placed at the disposal of the Committee for that purpose. The Report to be presented at the next meeting of the As- sociation. That the sum of 40/. be granted to Mr. Osler for the pur- pose of completing the Anemometer in the course of erection at Edinburgh, and also for Tabulating the Observations from the above instruments, in conjunction with those in Birming- ham and Plymouth. The Report to be presented at the next meeting of the As- sociation. That a sum of 60/. be placed at the disposal of Sir D. Brew- ster, Mr. Osler, and Professor Forbes, for erecting an Ane- RESEARCHES IN SCIENCE. XXVii mometer on Mr. Osler’s construction at Inverness, to connect these Observations with others already established there. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Major Sabine and Sir J. Herschel, be requested to provide two Actinometers, for Ob- servations on the intensity of Solar Radiation, to be made by Professor Agassiz, at considerable heights in the Alps, and that the sum of 10/. be placed at the disposal of the Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That the sum of 75/. be placed at the disposal of Sir D. Brewster, for the purpose of an Inquiry into the action of Gaseous and other Media upon the Solar Spectrum. The Report to be presented at the next meeting of the As- sociation. That the Committee already appointed to superintend the reduction of Lacaille’s Stars, consisting of Sir J. Herschel, the Astronomer Royal, and Mr. Henderson, be re-appointed ; and that the sum of 184J. 5s. (the balance of former grant) be placed at the disposal of the Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That a sum not exceeding 20/. be placed at the disposal of Mr. Snow Harris, for repairing and observing Whewell’s and Osler’s Anemometers. That a sum of 351. be placed at the disposal of Mr. Snow Harris, for defraying the expenses of the Hourly Register of the Barometer and Thermometer at Plymouth. That the sum of 20/. be placed at the disposal of Professor Forbes, for Tabulating Experiments on Subterranean Tem- perature. That a Committee, consisting of Sir J. Herschel, Professor Whewell, Dr. Peacock, Professor Lloyd, and Major Sabine, be appointed for conducting the co-operation of this Association in the system of simultaneous Magnetical and Meteorological Observations, and that a sum of 50/. be placed at their dis- posal. That a Committee, consisting of Major Sabine, Dr. R. Brown, XXVili REPORT—1840. Dr. Robinson, Sir J. Herschel, Professor Wheatstone, Sir D. Brewster, and Mr. Owen, Professors Thomas Graham and Miller, Sir W. Jardine, and Professor Robert Graham, be ap- pointed to superintend the Translation and Publication of Foreign Scientific Memoirs; and that the sum of 1002. be placed at the disposal of the Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That Mr. Mallet be requested to continue his experiments on the Action of Salt and Fresh Water on Iron, &c., and that 50/. be placed at his disposal for that purpose. That a Committee, consisting of Dr. Prout, Dr. J. Thomson, Professor Owen, Professor Graham, and Dr. R. D. Thomson, be requested to undertake a series of Researches on the Che- mistry and Physiology of Digestion, and the sum of 200/. to be placed at the disposal of the above Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of .Mr. Bryce, Mr. De la Beche, and Major Portlock, be requested to continue their Re- searches on the Mud of Rivers, and that the sum of 20/. be placed at the disposal of the Committee for that purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of the President of the Royal Society, the President of the Geological Society, R. I. Mur- chison, Esq., John Taylor, Esq., H.'T. De la Beche, Esq., and C. Vignoles, Esq. (with power to add to their number), be re- quested to take measures for procuring coloured drawings of Railway Sections before they are covered up; 200/. to be placed at their disposal for the purpose. _ The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of the Marquis of Northamp- ton, R. I. Murchison, Esq., and the Rev. W. Buckland, be re- quested to enable M. Agassiz to collect materials for a Report on the Fossil Fishes of Scotland, and particularly those of the Old Red Sandstone ; 100/. to be placed at their disposal for that purpose. - The Report to be presented at the next meeting of the As- sociation. | RESEARCHES IN SCIENCE. XXix That Captain Portlock be requested to institute a set of Experiments on the Temperature of Mines in Ireland, and that the sum of 10/. be placed at the disposal of Captain Portlock for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Lord Greenock, Mr. Milne, Professor Forbes, Mr. Paterson, Captain Portlock, and Mr. Bryce, be requested to Register the shocks of Earthquakes in Scotland and Ireland, and that the sum of 20/. be placed at the disposal of the Committee for that purpose. The Report to be presented at the next meeting of the As- sociation. That Professor Johnston and Mr. Jeffreys be a Committee to repeat Mr. Jeffreys’s experiments on the Solution of Silica in water of a high temperature, and that the sum of 25/. be placed at the disposal of the Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That Professor Henslow be requested to continue his Re- searches on the Preservation of Animal and Vegetable Sub- stances, and that the sum of 6/., being the unexpended portion of the former grant, be placed at the disposal of the Committee, The Report to be presented at the next meeting of the As- sociation. That the Committee already appointed for the purpose of preparing Maps for the illustration of the Geographical Distri- bution of Animals and Plants, have the sum of 25/. placed at their disposal for the completion of their arrangements. That the Committee already appointed for the purpose of in- vestigating, by means of the dredge, the Marine Zoology of Britain, be requested to continue their researches, and that the sum of 50/. be placed at the disposal of the Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Sir William Jardine, Mr. Selby, Mr. Yarrell, and Dr. Lankester, be requested to super- intend the application of the sum of 50/. towards the augmenta- tion of our knowledge of the Anoplura Britannie. That a Committee, consisting of Dr. Lankester, Dr. Arnott, XXX REPORT—1840. Dr. Greville, and Dr. Fleming, be requested to draw up a Report on the Plants and Animals existing in natural Thermal Springs and Mineral Waters, and in solutions artificially pre- pared, and that the sum of 6/. be placed at the disposal of the above-mentioned Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Mr. Hugh Strickland, Mr. Babington, and Professor Lindley, be requested to institute a series of experiments with a view to determine the longest period during which the Seeds of Plants can retain their vege- tative powers, the species or families of Plants in which these powers are of the longest duration, and the circumstances most favourable for their preservation, and that the sum of 10/. be placed at the disposal of the Committee for the purpose. The Report to be presented to the next meeting of the As- sociation. That the Committee already appointed for preparing a series of questions on the Human Race, be requested to complete and distribute the questions, and that the sum of 15/. be placed at the disposal of the Committee for the purpose of printing and distributing the queries. The Report of the Committee to be presented at the next meeting of the Association. That the Committee already appointed for conducting Ex- periments on Acrid Poisons be requested to continue their labours, and that the sum of 25/. be placed at the disposal of Dr. Roupell for the purpose. The Report to be presented at the next meeting of the As- sociation. That the Committee already appointed for Improvements in Acoustic Instruments be requested to continue their labours, and that the sum of 25/. be placed at the disposal of Dr. Yel- loly for the purpose. The Report to be presented at the next meeting of the As- sociation. That the Committee already appointed for the investigation of the Communication between Veins and Absorbents be re- quested to continue their labours, and that the sum of 25/. be placed at the disposal of Dr. Roget for the purpose. The Report to be presented at the next meeting of the As- sociation. RESEARCHES IN SCIENCE. ‘XxXXI That a Committee, consisting of Sir Charles Lemon, Mr. Porter, Mr. Hallam, Colonel Sykes, and Mr. Heywood, be re- quested to encourage Inquiries into the actual state of Educa- tion in Great Britain, considered merely as to numerical ana- lysis, and that the sum of 100/. be placed at the disposal of the above-named Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Colonel Sykes, Lord San- don, Mr. Porter, Mr. Heywood, Dr. Alison, Dr. Cowan, Mr. Chadwick, and Mr. Watt, be requested to inquire into Vital Statistics, and that the sum of 100/. be placed at the disposal of the Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Professor Johnston, Mr. Wharton, Mr. Wilson, Mr. William Murray, Mr. Chas. Baird, Mr. Thomas Edington, jun., Mr. De la Beche, and Mr. D. Milne, be requested to inquire into the Mining Statistics of the British Coal Fields, and that the sum of 25/. be placed at the disposal of the Committee for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Mr. John Enys, Mr. John Taylor, Mr. Fairbairn, Mr. Hodgkinson, Mr. Simpson, and Mr. Scott Russell, be requested to obtain a set of Experiments on the Temperature of maximum effect in the Condensers of Steam Engines, and that the sum of 25/. be placed at their disposal for the purpose. The Report to be presented at the next meeting of the As- sociation. That a Committee, consisting of Sir John Robison and Sir Thomas Brisbane, be requested to procure, and to hold at the disposal of the Association, a set of Roberts’s (of Paris) Mea- surers of short intervals of Time, to be employed, in the first instance, in completing the Experiments on Waves and on-the Forms of Vessels; and that the sum of 30/. be placed at their disposal for the purpose. The instruments to be presented at the next meeting of the Association. That a Committee, consisting of Professor Moseley, Mr. Enys, and Mr. Hodgkinson, be requested to procure the dyna- XXxli REPORT—1840. mometric apparatus of Mr. Poncelet, and to obtain a series of Experiments on the duty of Steam Engines by means of that apparatus ; the sum of 100/. to be placed at their disposal for that purpose. The apparatus to be presented at the next meeting of the Association. That the Committee already appointed on the Forms of Vessels, be requested to complete their experiments; the sum of 100/. to be placed at their disposal for that purpose. The Report to be presented at the next meeting of the As- sociation. Synopsis of Sums appropriated to Scientific Objects by the General Committee at the Glasgow Meeting. Section A. Hourly Meteorological Observations at Kingussie £ s. d. and Thnverness! Gu AAR Sy Sas Ls Oe re) Tide Discussions: “het ee os ORO) Pee aaa Tide Discussions: Bristol . . . . ice & “APs Mountain Barometer and Pherihonietsr™ JO Oe) ee Reduction of Meteorological Observations. . . 100 O O Nomenclature of ‘Stars. 2.00%): ': 3. 3 co. .. Re Stars in Histoire Céleste . . . se es. SOO British Association Catalogue of Stars ets ose Reduction of Anemometrical Observations . . 40 0 O Erection of Anemometer at Inverness . . . . 60 0 0 Two Actinometers . Seat as sc od oc age een ee Action of Gases on Light be ig) ey MEP RESTING Lacaille’s Stars... eee. Meteorological Observations at Plymouth c+ eo Anemometer at Plymouth . . .. . o! Se i ee Tabulation of Experiments on Subterranean Tem- perature wim. eee sty RR Ge See 20 0 0 Magnetic Co-operation ty tees ogtetoGhe ds 1) TSOSERRIone £1149 5 O SEcTION B, Sereutiic Memoirs .. .. sc |: sass eelea, =) Action of Water on Iron . . ove se OPaORS® Chemistry and Physiology of Digestion he ts 20s £350 0 0 : : SYNOPSIS. Section C, XXXiii SEWERS or a A ak tne « £20, 0 O Beemeections ws) ois Ye PD eo gggg? oO Fishes of Old Red Sandstone. . . . . 7) RO eh Subterranean Temperature in Ireland . . . . 10 0 0 Barthquake Registration . ...... 2. #20 0 0 Solution of Silica in Water at High Temperatures 25 O O £375 0 O Section D. Preservation of Animal and Vegetable Substances Oo -8 tern Mipsis ek eit) TOR ar tol Marine Zoology . . . Eg IE Tali oh aa ce EES BK al Seeanura Britannia’ 4.6 0° OS ee igo 6 Plants and Animals in Mineral Waters . . aA ae! ee 2) Vegetative power of Seeds. . . . . .. . +10 0 0 mer Oe OE Ce OTP LE YTS sunt ee eae £162 60 0 Section E. meme Puisons Ye y P2haye) eh oo Sagan, S102 LOSER Acoustic Instruments .... . GRO Moy Da LOUNG Veinsand Absorbents ........ + bn) BROOUNG £75 O O Section F, Statistics of Education . . . catia Sgr Pog) EG Qo ae Wital Statistics . °° YS, oe ee ote ee eEOG: KOLO meoamie Statistics: LDN ope Yolehwege puri gehe 0 £225 0 O Section G. Temperature of maximum condensation of Steam 25 O O Roberts’ Chronometers . . . .” AS EAs SOF O20 Dynamometric Instruments... . . . . 100 0 0 Forms of Vessels . . . . . Peredial: Ure Lene NMA Oy £255 Oo O Total of Money Grants . . . £2591 5 0 1840, c XXXIV REPORT—1840. Extracts from Resolutions of the General Committee. Committees and individuals, to whom grants of money for scientific purposes 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 dis- posable on each grant. Grants of pecuniary aid for scientific purposes from the funds of the Association 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., 2, Duke Street, Adelphi, 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 continuation of Researches at the cost of the Association, the sum named shall be deemed to include the specified balance igh may remain unpaid on the former grant for the same object. On Thursday evening, September 17th, the President, the Most Noble the Marquis of Breadalbane, took the Chair in the Theatre. Mr. Murchison read the Address of the General Secretaries (see next page). On Wednesday, at 3 p.M., the Conctupine GENERAL Meet1nNG of the Association took place in the Theatre, when an account of the ProcEEDINGS OF THE GENERAL ComMIT- TEE was read by Major Sabine. ADDRESS RODERICK IMPEY MURCHISON, F.RS., F,.G.S. AND MAJOR EDWARD SABINE, V.P.R.S. In entering upon the duty assigned to us, we heartily congratulate our associates on this our second assembly in Scotland. As on our first visit we were sustained by the intellectual force of the metropolis of this kingdom, so now, by visiting the chief mart of Scottish com- merce, and an ancient seat of learning, we hope to double the numbers of our northern auxiliaries. Supported by a fresh accession of the property and intelligence of this land, we are now led on by a noble Marquis, who, disdaining not the fields we try to win, may be cited as the first Highland chieftain who, proclaiming that knowledge is power, is proud to place himself at the head of the clans of science. If such be our chief, what is our chosen ground ?—raised through the industry and genius of her sons, to a pinnacle of commercial gran- deur, well can this city estimate her obligations to science! Happily as she is placed, and surrounded as she is by earth’s fairest gifts, she feels how much her progress depends upon an acquaintance with the true structure of the rich deposits which form her subsoil; and great as they are, she clearly sees that her manufactures may at a moment take a new flight by new mechanical discoveries. For she it is, you all know, who nurtured the man whose genius has changed the tide of human interests, by calling into active energy a power which (as wielded by him), in abridging time and space, has doubled the value of human life, and has established for his memory a lasting claim on __ the gratitude of the civilized world. The names of Watt and Glasgow _ are united in imperishable records! - In sucha city, then, surrounded by such recollections, encouraged c2 XXXV1 by an illustrious and time-honoured university, and fostered by the ancient leaders of the people, may we not augur that this Meeting of the British Association shall rival the most useful of our previous as- semblies, and exhibit undoubted proofs of the increasing prosperity of the British Association ? Not attempting an analysis of the general advance of science in the year that has passed since our meeting at Birmingham, we shall re- strict ourselves, on the present occasion, to a brief review of what the British Association has directly effected in that interval of time, as re- corded in the last published volume of our Transactions, From this straight path of our duty we shall only deviate in offering a few gene- ral remarks on subjects intimately connected with the well-being and dignity of our Institution. One of the most important—perhaps the most important service to science—which it is the peculiar duty of the Association to confer, is that which arises from its relation to the Government,—the right which it claims to make known the wants of science, and to demand for them that aid which it is beyond the power of any scientific body to bestow. In the fulfilment of this important and responsible duty, the Association has continued to act upon the principle already laid down in the Address of the General Secretaries at the meeting at Newcastle in 1838, namely, to seek the aid of Government in no case of doubtful or minor importance ; and to seek it only when the resources of indi- viduals, or of individual bodies, shall have proved unequal to the de- mand. The caution which it has observed in this respect has been eminently displayed in the part which it has taken with reference to the Antarctic expedition, and to the fixed magnetical observatories. It abstained from recommending the former to the Government until it had called for, and obtained from Major Sabine, by whom the im- portance of such an expedition was first urged, a report in which that importance was placed beyond all doubt; and it withheld from urging the latter, although its necessity was fully felt by some of its own members, until the letter of Baron Humboldt to the Duke of Sussex gave authority and force to its recommendation. The delay which has in consequence occurred, has been productive of signal benefit to each branch of this great twofold undertaking. Since the time alluded to, our views of the objects of investigation in terrestrial magnetism have been greatly enlarged, at the same time that they have become more distinct. Major Sabine’s memoir on the Intensity of Terrestrial Magnetism has served to point out the most interesting portions of the surface of the globe, as respects the distri- XXXVil bution of the magnetic force, and has indicated, in the clearest manner, what still remained for observation to perform; and the beautiful theory of M. Gauss, which has been partly built upon the data af- forded by the same memoir,—while it has assigned the most probable configuration of the magnetic lines of declination, inclination, and intensity,—has done the same service with respect to all the three elements. In another point of view, also, delay has proved of great value to both branches of the undertaking, but more especially to the fixed ob- servatories. Our means of instrumental research have, since the time of their first projection, received great improvements, as well in their adequacy to the objects of inquiry, as in their precision; and finally, the two great lines of inquiry—the research of the distribution of Ter- restrial Magnetism on the earth’s surface,—and the investigation of its variations, secular, periodic, and irregular,—have been permitted to proceed pari passu. Last of all, the prudent caution, and vigilant care, which the two great scientific bodies, the Royal Society and the British Association, have exhibited, both in the origin and progress of the undertaking, have naturally inspired the Government with confidence ; and while on the one hand science has not hesitated to demand of the country all that was requisite to give completeness to a great design, so on the other, the Government of the country has not hesitated to yield, with a liberal and unsparing hand, every request the importance of which was so well guaranteed. But while we thus enumerate the benefits which have resulted to magnetical science from the delay, it must be also acknowledged that something has been lost also, not to science, but to British glory. Al- though terrestrial magnetism stood forward as the prominent object of the Antarctic expedition, yet it was also destined to advance our knowledge of the “ physique du globe,’ in all its branches, and especially in that of geography. Had the project of an Antarctic expedition been acceded to when it was first proposed, viz. at the meeting of the British Association, in Dublin, in 1835, there can be no reasonable doubt, that a discovery of coast, which by its extent may almost be de- signated as that of a Southern Continent, situated in the very region to which its efforts were to have been chiefly directed, must have fallen to its lot ; and the flag of England been once more the first to wave over an unknown land. But while, as Britons, we mourn over the loss of a prize which it well became Britain and British seamen to have made their own, it is our part too as Britons, as well as men of science, to hail the great discovery—one of the very few great geographical dis- XXXViil coveries which remained unmade ;—and to congratulate those by whom it has been achieved, those whom we are proud to acknowledge as fellow-labourers, and who have proved themselves in this instance our successful rivals in an honourable and generous emulation. The caution which has characterized the British Association in the origination of this great undertaking, has been followed up by the Royal Society in the manner in which it has planned the details, and in the vigilant care with which it has watched over the execution. Of the success which has attended this portion of the work, the strongest proof has been already given in the unhesitating adoption of the same scheme of observation by many of the continental observers, and in the wide extension which it has already received in other quarters of the globe. All that yet remains is to provide for the speedy publication of the results. The enormous mass of observations which will be gathered in, in the course of three years, by the observatories esta- blished under British auspices, and by the Antarctic expedition, will render this part of the task one of great expense and labour. To meet the former, we must again look to the Government, and to the East India Company, who will certainly not fail to present the result of their munificence to the world in an accessible form. The latter can only be overcome by a well-organized system. The planning of this system, will, of course, be one of the first duties of the Royal Society ; and it is important that it should be so arranged, that while every facility in the way of reduction may be given to those who shall hereafter engage in the theoretical discussion of the observations, care is taken at the same time that the data are presented entire, with- out mutilation or abridgement. The Council of the Royal Society, will, doubtless, be greatly assisted in this duty by the eminent indivi- dual who has had in every way so large a share in the formation of these widely scattered magnetic establishments, and whose own obser- vatory, founded by the munificence of the Dublin University, has nearly completed a twelve months’ magnetic observations on that en- larged and complete system of which it set the first example. In referring, as we have done, to those most valuable services which the Royal Society have rendered, and are continuing to render, in di- recting and superintending the details of this great undertaking, in both its branches, it is right that, on the part of the British Association, we should express the cordial satisfaction and delight with which we have witnessed their exertions, united with our own in this common cause ; nor should we omit to recognize how much this desirable con- currence has been promoted by the influence of the noble President of the Royal Society, the Marquis of Northampton, whom, as on so many XXKIX former occasions, we have the pleasure of seeing amongst us,—one of our warmest supporters and most active members. In the volume of our Transactions now under notice, is contained the memorial presented to Lord Melbourne by the Committee of the British Association, appointed to represent to Her Majesty’s Govern- ment the recommendations of the Association on the subject of Ter- restrial Magnetism. This memorial is one of many services which have been rendered to our cause by Sir John Herschel, whose name, whose influence, and whose exertions, since our meeting two years since at Newcastle, have largely contributed to place the subject where it now stands. The devoted labour of other of our members has long been given to an object which they have had deeply at heart, viz. the advancement of the science of terrestrial magnetism ; but the sacrifice which Sir John Herschel has made of time, diverted from the great work, in which his ardent love of astronomy, his own personal fame, and his father’s memory are all deeply concerned, the more ur- gently demands from our justice a grateful mention, because the science of magnetism had no claim on him, beyond the interest felt in every branch of science, by one to whom no part of its wide field is strange, and the regard which a national undertaking such as this de- served, from the person who occupies his distinguished station amongst the leaders of British science. The advancement of human knowledge, which may be reckoned upon as the certain consequence of the Antarctic expedition (should Providence crown it with success), and of the arrangements connected with it, is of so extensive a nature, and of such incalculable importance, that no juster title to real and lasting glory than it may be expected to confer, has been earned by any country at any period of time; no- thing has ever been attempted by England more worthy of the place which she occupies in the scale of nations. When much which now appears of magnitude in the eyes of politicians has passed into insig- nificance, the fruits of this undertaking will distinguish the age which gave it birth, and, engraved on the durable records of science, will for ever reflect honour on the scientific bodies which planned and promoted it, and on the Government which, with so much liberality, has carried it into effect. Were the value of this Association, Gentlemen, to be measured only by the part which it has taken in suggesting and urging this one ob- ject, there might here be enough to satisfy the doubts of those who question its utility. To overlook such acts as these, and the power of public usefulness which they indicate, to scrutinize with microscopic xl view the minute defects incidental to every numerous assemblage of men, to watch with critical fastidiousness the taste of every word which might be uttered by individuals amongst us, instead of casting a master’s eye over the work which has been done, and is doing, at our meetings, is no mark of superior discernment and comprehensive wis- dom, but is evidence rather of a confinement to narrow views, and an indulgence of vain and ignoble passions. But to proceed with our useful efforts,—one of the principal ob- jects of our Annual Volumes, is the publication in the most authentic form of the results of special researches, undertaken by the request, and prosecuted in many instances at the cost, of the Association. It is a trite remark, that if a man of talent has but fair play, he will soon secure to himself his due place in public estimation. We fully admit the truth of this in many instances, and above all where the points of research are connected with commerce and the useful arts ; but many also are the subtile threads of knowledge, which, destined at some future day to be woven into the great web in which all the sciences are knit together, are yet not appreciable to the vulgar eye, and if simply submitted to public judgment, would too often meet with silent neglect. Numberless, we say, are the subjects (and if your Association exceeds a centenary, still more numerous will they be) with which the retired and skilful man may wish to grapple, and still be deterred by his want of opportunity or of means. Thenis it that, adopting the well-balanced recommendations of the men in whose capacity and rectitude you con- fide, you step forward with your aids, and bring about these recondite researches, the result of which, in the volume under our notice, we now proceed to consider. The first of these inquiries to which we advert, you called for at the hands of Professor Owen, upon “British Fossil Reptiles,” one of the branches of Natural History, on a correct knowledge of which the development of geology is intimately dependent. The merits of the author selected for this inquiry are now widely recognized, and he has, with justice, been approved as the worthy suc- cessor of John Hunter, that illustrious Scotchman who laid the founda- tion of comparative anatomy in the British isles. That this science is now taking a fresh spring, would, we are persuaded, be the opinion of Cuvier himself, could that eminent man view the progress which our young countryman is making towards the completion of the temple of which the French naturalist was the great architect. It is therefore a pleasing reflection, that when we solicited Professor Owen to work out this subject, we did not follow in the wake of Europe’s praise, but xii led the way (as this Association ought always to do), in drawing forth the man of genius and of worth; and the value of our choice has been since stamped by the approval of the French Institute. If Englishmen* first perceived something of the natural affinities of Paleosaurians, it was reserved for Cuvier to complete all such preli- minary labour. The publication of his splendid chapters on the os- teology of the crocodile and other reptiles, drew new attention and more intelligent scrutiny to these remains ; and it ought to be a sub- ject of honest pride to us to reflect, that the most interesting fruits of the researches of that great anatomist were early gathered by the English paleontologists, Clift and Hume. One of our leaders}, whose report on geology ornaments the volumes of this Association, formed the genus Plesiosaurus, on an enlarged view of the relation subsisting between the ancient and modern forms of reptile life; while shortly after Buck- land established the genus Megalosaurus, and Mantell, Jguanodon and Hyleosaurus, worthy rivals of the Geo-Sauri and Moso-Sauri of Cu- vier. The other Englishmen who have best toiled in this field, are De la Beche, Hawkins, and Sir Philip Egerton. Yet although this report is on British reptiles, we are fully alive to the great progress which this department has made, and is making, on the Continent, through the labours of Count Minster, Jager, and Hermann Von Meyer. The last-mentioned naturalist has been for some time preparing a series of exquisite drawings of very many forms unknown to us in England, most of which have been detected in the ** Muschelkalk,” a formation not hitherto discovered in the British isles. Yet despite of all that had been accomplished in our own country or elsewhere, Professor Owen has thrown a new light of classification on this subject, founded on many newly discovered peculiarities of osse- ous structure, and has vastly augmented our acquaintance with new forms, by describing sixteen species of Plesiosauri, three of which only had been recognisably described by other writers; and ten species of Ichthyosauri, five of which are new to science. Such results were not to be obtained without much labour ; and previous to drawing up his report, Professor Owen had visited the principal depositories of Ena- hosauri described by foreign writers, as well as most of the public and private collections of Britain, This, the first part of Mr. Owen’s re- port, concludes with a general review of the geological relations and extent of the strata through which he has traced the remains of British Enaliosauri. The materials which he has collected for the second and concluding portion of his report on the terrestrial and crocodilean * Stukeley. + Conybeare. xlii Sauria, the Chelonia, Ophidian, and Batrachian reptiles, are equally numerous, and the results of these researches will be laid before the Association at our next meeting. Deeply impressed as we are with the value of this report, we cannot conclude a notice of it, without again alluding to its origin, in the words of Professor Owen himself. “TI could not,” says he, “ have ventured to have proposed to myself the British Fossil Reptilia as a subject of continuous and systematic research, without the aid and encouragement which the British As- sociation has liberally granted to me for that purpose.” Mr. Edward Forbes, whose labours in detecting the difference of species and varieties among the existing marine testacea of our shores, have been most praiseworthy, has on this occasion given us a valuable report on the pulmoniferous mollusca of the British isles. The varia- tions in the distribution of the species in this class of animals, are shown by him to depend both upon climate and upon soil, the structure of the country (or geological conditions) having quite as much share in such varied distribution, as the greatest diversity of temperature. The Association has also to thank the author for most useful tables, which show the distribution of the pulmoniferous mollusca in our is- lands, and their relations to those of Europe generally. One of the most interesting fruits of modern experimental research is the knowledge of the fact, that electrical currents are in continual cir- culation below the surface of the earth. Whether these currents, so powerful in developing magnetical and chemical phenomena, are con- fined to mineral veins and particular arrangements of metal and rock, or generally capable of detection by refined apparatus well applied, ap- peared a question of sufficient importance to deserve at least a trial on the part of the Association. Our present volume records the result of such a trial on the ancient and very regularly stratified rocks of Cum- berland, consisting of limestone, sandstone, shale, and coal, so super- imposed in many repetitions as to resemble not a little the common arrangement of a voltaic pile. ~Varied experiments, with a galvano- meter of considerable delicacy, failed, however, to detect, in these seemingly favourable circumstances, any electrical current. The extensive and rapidly increasing applications of iron to public and private structures of all kinds in which durability of material is a first requisite, have made it highly desirable to possess accurate informa- tion respecting the nature of the chemical forces which effect the de- struction of this hard and apparently intractable metal. The preser- vation of iron from oxidation and corrosion is indeed an object of para- mount importance in civil engineering. The Association was, there- fore, anxious to direct inquiry to this subject, and gladly availed itself xiii of the assistance of Mr. Mallet, a gentleman peculiarly qualified for such investigations, both from his knowledge as a chemist, and from his opportunities of observation as a practical engineer. An extensive series of experiments has accordingly been instituted by him, with the support of the Association, on the action of sea and river water, in dif- ferent circumstances as to purity and temperature, upon a large number of specimens of both cast and wrought iron of different kinds. These experiments are still in progress, and the effects are observed from time totime. They will afford valuable data for the engineer, and form the principal object of the inquiry; but a period of a few years will be required for its completion. In the mean time, Mr. Mallet has fur- nished a report on the present state of our knowledge of the subject, drawn from various published sources, and from his own extensive ob- servations. In this report he examines very fully the general condi- tions of the oxidation of iron, and how this operation is greatly pro- moted, although modified in its results, by sea water; also in what manner the tendency to corrosion is affected by the composition, the grain, porosity, and other mechanical properties of the different com- mercial varieties of iron. The influence of minute quantities of other metals, in imparting durability to iron, is also considered. Mr. Mal- let devotes much attention to the consequences of the galvanic asso- ciation of different metals with iron, a subject of recent interest from the applications of zinc and other metals to protect iron, which are at present agitated. He concludes this, his first report, by recommend- ing a series of inquiries, ten in number, which will supply the desiderata immediately required by the engineer and by the chemist. We have next to notice a report by Professor Powell, on the present state of our knowledge of refractive indices for the standard rays of the solar spectrum in different media. The difficulty which the fact of the dispersion of light has offered to the universal application of the undulatory theory, has been in a great measure removed by the ana- lysis of Cauchy and others, who have considered the distances of the undulatory particles as quantities comparable to the length of a wave ; velocities of propagation of the different rays of the spectrum are made to depend upon the length of wave which constitutes a ray of a given colour, and upon certain constants proper to the medium; these constants being obtained from observations on refractive indices for certain definite rays (or dark lines) of the spectrum, the refrangibility of any other definite ray (whose wave-length has been ascertained by examining an interference-spectrum) becomes known, and may be compared with observation as a test of theory ; such experiments have been made by Frauenhofer, Rudberg, and Professor Powell, who has xliv given a tabular view of the various results, without, however, insti- tuting the comparison between theory and observation, which it would be desirable to extend further than has yet beendone. It would be important also to elucidate the disturbing effect of temperature, which prevents even existing observations from being rigorously com- parable. The calculations respecting the tides, which have been prosecuted by the aid of the Association ever since its institution, have been con- tinued this year by Mr. Bunt, under the directions of Mr. Whewell. These calculations have now reached such a point, that the mathemati- cian, instead of being, as at the beginning of this period, content with the first rude approximations, is now struggling to obtain the last de- gree of accuracy. The country in which we are now assembled, has always been con- spicuous for attention to meteorology, a branch of physical science, in which the British Association, with its power of combining the efforts of many observers in distant quarters of the globe, may hope to be especially useful. In Scotland, Leslie opened a new train of inquiry, by examining the earth’s temperature at different depths; and his successor in the Uni- versity of Edinburgh, is now directing, at the request of the Associa- tion, a large and complete course of experiments on that interesting subject. Framed in conformity with the plans adopted for similar ob- jects by Arago and Quetelet, these researches of Professor Forbes contain also the means of determining the power of conducting heat, which different sorts of rock possess; and may thus throw light on some of those peculiarities in the distribution of temperature at greater depths below the surface, which have become known by experience, but are not explained by theory. In Scotland, Sir David Brewster was the first to obtain an hourly meteorological journal for a series of years, and to draw from that fer- tile source new and important deductions, which have had a powerful influence on the progress of scientific meteorology. How gratifying to receive, through the same hands, after the lapse of nearly 15 years anadditional contribution of the same kind, and from the same country ; but embracing new conditions, on a new line of operations, in order to obtain new results! By the observations now in progress at Inverness and at Kingussie, the influence of elevation in modifying the laws, which have been found to govern the hourly distribution of heat near the level of the sea, may be discovered, and thus a great addition be made to the experimental results, for which science has long been grateful to the distinguished philosopher we have named, and which xlv have been described as “the highest value to meteorology, and as the only channel through which any specific practical information can be obtained in this most interesting department of physics.” This is no ordinary praise. It is the just tribute of one who is worthy to offer it; one, who at the call of the British Association, has conducted at Plymouth a still more extensive series of similar obser- vations, and has added to them hourly comparisons of the temperature and moisture of the air, and an hourly record of barometric oscillations. Mr. Snow Harris has presented in a few pages of our last report, the precious results of (70,000) observations, and thus rendered them immediately available in the foundations of accurate meteorology. The documents thus patiently collected, are, however, not yet ex- hausted in value; they may be again and again called into the court of science, and made to yield testimony to other, and as yet, unsuspected truths. They must not be lost. Shall we lay them by in manuscript among other unconsulted records of the past labours of men, or by un- dertaking their publication, do justice to our workmen, and establish a new claim on the imitation of the present, and the gratitude of future days? This question is of serious import. Already, stimulated by success in thermometric registration, we have set to work on a more perplexing problem; we have resolved to bind even the wandering winds in the magic of numbers. While we speak, the beautiful engines of our Whewells and Oslers are tracing at every instant of time, the displacements of the atmosphere at Cambridge, at Plymouth, at Bir- mingham, in Edinburgh, in Canada, in St. Helena, and at the Cape of Good Hope ; and ere long we may hope to view associated in one dia- gram, the simultaneous movements of the air over Europe, America, Africa, India, and Australia, recorded with instruments which we have chosen, by men whom we have set to work, Amongst the causes which tend to retard the progress of science, few, perhaps, operate more widely than the impediment to a free and rapid communication of thought and of experiments, occasioned by difference of language. It appeared to the British Association, that this impediment might in some degree be removed, as far as regards our own country, by procuring, and causing to be published, transla- tions of foreign scientific memoirs judiciously selected. Accordingly at each of the meetings at Newcastle and Birmingham a grant was placed at the disposal of a committee appointed to carry this purpose into effect. Aided by several contributions which have been gratui- tously presented to them, the committee have been enabled in the two last years, to publish translations of fourteen memoirs on subjects of ’ xvi prominent interest and importance in the mathematical and physical sciences, bearing the names of some of the most eminent of the con- tinental philosophers. In concluding this imperfect review of our recent proceedings, we are led to observe, that in two essential respects the British Association differs from all the annual scientific meetings of the Continent; no one of which has printed Transactions or employed money in aiding special researches. We also differ from them in the communications which, in the name of the representatives of science assembled from all parts of the United Kingdom, we feel ourselves authorized to make to our Government, on subjects connected with the scientific character of the nation. On our first visit to Scotland, for example, we felt it to be an opprobrium, that this enlightened kingdom should, in one essen- tial feature of civilization, be still behind many of the continental states; and we prepared an address to his late Majesty’s Government, urging the necessity for the construction, without delay, of a map of Scotland, founded on the trigonometrical survey. Representations to the same effect have since been made by the Royal Society of Scotland, and by the Highland Society, and the subject has now engaged that atten- tion, which will, we trust, soon procure for this country the first sheets of a large and complete map. Should it then be asked, why are the men of highest station happy to associate and mingle with us in official duties ?—why have the heads of the noble houses of Fitzwilliam, Lansdowne*, Northampton, Bur- lington, Northumberland, and Breadalbane, alternated in presiding over us, with our Bucklands, our Sedgwicks, our Brisbanes, our Lloyds, and our Harcourts ?—why indeed, on this very occasion, has Argyll himself, overlooking the claims due to his high position, and his ancient lineage, come forward to act with us, and even to serve in asubordinate office ? may we not reply, that it is, we believe, a consequence of the just ap- preciation on the part of these patriotic and enlightened noblemen, of the beneficial influences which this Association exercises in so many ways on the sources of the nation’s power and honour ? If we have hitherto dwelt almost exclusively on the value of our transactions, researches, recommendations, and the good application of our finances, let it not, however, be supposed, that we are not also * The Marquis of Lansdowne, who had accepted the office (1836), was prevented from attending by deep domestic affliction, and the Marquis of Northampton cheer- fully supplied his place, xlvii alive to the advantages which flow from the social intercourse of these meetings, by bringing together, into friendly communion, from distant parts, those who are struggling on in advancing experimental science. This principle of union.(which we are proud to have borrowed from our German brethren) has indeed been hitherto found to work so well amongst our own countrymen, that we cannot but doubly recognize its value when we see assembled so many distinguished persons from foreign countries. In the presence of these eminent men*, we forbear to allude to individual distinctions, conscious that any brief attempt of our own would fall far short of a true estimate of merits, the high order of which is known to every cultivator of science. Well, how- ever, may we rejoice in having drawn such spirits to our Isle ; valuable, we trust, may be the comparisons we shall make between the steps which the sciences are making in their countries and in our own. That advantages, indeed, of no mean order arise from such social intercourse, is a feeling now so prevalent, that foreign national associa- tions for the promotion of natural knowledge, have rapidiy increased. Germany, France, and Italy have their annual Assemblies, and our allies of the Northern States hold their sittings beyond the Baltic. In all this there is doubtless much good, but an occasional more exten- sive intercourse of a similar nature, to be repeated at certain intervals, is greatly to be desired. It has therefore appeared to us (and we say it after consultation with many of our continental friends, who equally feel the disadvantage), that the formation of a general congress of science might be promoted at this meeting, which, not interfering with any assemblies yet fixed upon, or even contemplated, may be so arranged as to permit the at- tendance of the officers and active members of each national scientific institution. Should the British Association take the first step in proposing a measure of this kind by soliciting the illustrious Humboldt to act as President, we are sure that scientific men of all nations would gladly unite in offering this homage to a man whose life and fortune have been spent in their cause, whose voice has been so instrumental in awakening Europe to the inquiry into the laws of terrestrial mag- netism, and whose ardent search after nature’s truths has triumphed over the Andes and the Altai. If such be your suggestion, then will a fresh laurel be added to the wreath to this city. She who, through the power bequeathed toher by * Encke, Link, Jacobi, &c, xl vili her illustrious offspring, conveys with rapid transit her inventions and her produce to the remotest lands, well can she estimate the value of an union of men whose labours can but tend to cement the bonds of general peace. In such a body the British representatives would, we trust, form no inconspicuous band; and with minds strengthened by the infusion of fresh knowledge, they would, on re-assembling for our own national ends, the better sustain the permanent and successful career of the British Association. REPORTS ON THE STATE OF SCIENCE. Report on the recent progress of discovery relative to Radiant Heat, supplementary to a former Report on the same sub- ject inserted in the \st volume of the Reports of the British Association for the Advancement of Science. By the Rev. BapeEn PowsE tt, M.A., F.R.S., F.R.Ast.S., F.G.S., Savilian Professor of Geometry in the University of Oxford. Havine been one of those whoat the first institution of the British Association were applied to, to prepare reports on the state and progress of the different branches of science, and ha- ving in consequence laid before the Association at the Oxford meeting in 1832 such a review of the subject of Radiant Heat, I have felt peculiar satisfaction in being again honoured by a request from the Council to furnish a second report supplement- ary to the former, embracing the progress of knowledge in that department from the period to which the first report extends, up to the present time. Such a supplementary account has been rendered peculiarly necessary, from the great number and high importance of the results which have been arrived at by several eminent experi- meuters in the interval which has elapsed: and though much is still required to be done before we attain complete and satis- factory grounds for an unexceptionable theory of radiant heat, yet the discoveries recently made have at least tended greatly to modify all our previous conceptions, and to enable us to refer large classes of the phenomena to something like a simple and common principle. In my former Report I divided the subject under various heads, derived from what appeared, in the existing state of our know- VOL, 1x. 1840. B by REvPoRT—1840. ledge, well-marked distinctions between several kinds of effects ascribed to radiant heat. The more recent discoveries have in a great degree so changed our views of the subject, that these divisions cannot with any advantage or convenience be adhered to. One grand principle of arrangement, however, has been newly supplied in the capital discovery of the polarization of heat; so that all the researches we have to describe will be conve- niently classed under two heads, as they relate—first, to radiant heat in its ordinary or unpolarized state ; and secondly, to its polarized condition. Division I.—Unpotarizep Heat. Transmission and Refraction of Heat : Melloni. Since the period to which my former report extends, various notices have from time to time been given to the British Associa- tion relative to the more important discoveries connected with radiant heat. My former report includes a statement of some of the first researches of M. Melloni. At the Cambidge meet- ing, in 1833, Prof. Forbes gave some account of the further investigations in which M. Melloni was then engaged, including a brief abstract by M. Melloni himself of the chief results he had then obtained*. The full details were subsequently embo- died in his several memoirs. In the earlier part of these researches, M. Melloni had found that the quantity of calorific rays which traverses a screen, is proportional to the temperature of the source: but the difference constantly diminishes as the thickness of the screen is less, until with very thin laminz it is insensible. This proves that the resistance to the passage of heat is not exerted at the surface, but in the interior of the mass. With the solar rays, he observed that with various thicknesses of sulpliate of lime, water and acids, the increase of interception, owing to increased thickness, is greater for the less refrangible rays of the spectrum. With terrestrial sources he found that a plate of glass, 2 mm. in thickness, stops, out of 100 rays, from flame 45, from copper at 950° cent. (incandescent) 70, from boiling mercury 92, from boiling water 100. Comparing the transmissive powers of a great number of substances in a crystallized state, he concluded that the diather- maneity for the rays of alamp was proportional to their refrac- tive powers ; but in uncrystallized bodies no such law could be traced. * See Third Report, p. 381-2. REPORT ON RADIANT HEAT, 3 It was in the course of these researches that the author made the important discovery of the singular property possessed by Rock Sa tr, viz. that it is almost entirely permeable to heat even from non-luminous sources. He found its transmissive power six or eight times greater than that of an equal thickness of alum, which had nearly the same transparency and refractive power. He also discovered that (unlike other diathermanous media) it is equally diathermanous to ail species of heat, 7. e. to heat from sources of all degrees of luminosity or obscurity; or that it transmits in every case an equal proportion of the heat incident. Thus he found a plate of 7 mm. (*28 inch) in thickness trans- mits about 92 out of 100 rays, whether from flame, red-hot iron, water at 212°, or at 120° Fahrenheit. A plate 1 inch thick gave a similar constant ratio. M. Melloni’s ** Memoir on the Free Transmission of Radiant Heat through Solid and Liquid Bodies,” was presented to the Academy of Sciences at Paris, Feb. 4, 1833, and published in the Ann. de Chimie, No. liii. p. 1 ; a translation of it is given in Taylor’s Scientific Memoirs, Part I. The author commences with a slight sketch of the researches of previous experimenters, but omits to notice any distinctions between the characters of the heat from different sources, or the different Ainds of heat from one and the same source, when lu- minous, especially as indicated by my experiments published in the Phil. Trans. for 1825. He then proceeds to some “ general considerations on free transmission of caloric through bodies, and the manner of mea- suring it by means of the thermo-multiplier.”” This, in fact, con- stitutes a supplementary and more enlarged portion of his for- mer researches. He goes into extensive details on the precau- tions necessary to be used in such investigations ; especially for guarding against the interference of secondary radiation: as this changes with the change of place of the screen, he thus al- lows for its effects. He also gives some general observations on the use of the galvanometer, and the correct estimation of the forces acting upon it. The next subject of inquiry is the effect due to “the polish, thickness, and nature of the screens.’’ The source of heat being a lamp, screens were employed of glass rendered of different de- grees of opacity by grinding, &c.; and the effects by transmis- sion through them were found to be in proportion to the trans- parency, or that the heat follows the same proportion as the light. The effect of liquids between glass plates was then tried; and more rays were found to be absorbed in proportion to the increase B2 4 3 REPoRtT—1840. of thickness. Different numbers of glass screens were also em- ployed in combination ; the same conclusion also held good. The results with a numerous series of screens of various me- dia, solid and liquid, were then tried, and are stated in a series of tables :— Table I. Various kinds of uncoloured glass. Table II. Liquids: to give a general sketch, the order of transmission was as follows, beginning with the greatest :— Carburet of silver. Chlorides. Oils. Acids. Water. Table III. Crystallized bodies, transparent and opake; the results follow no relation to transparency: the following is the general order :— Rock salt. Various crystals. Alum. Sulphate of copper—no effect. Table IV. Coloured glasses. Red and violet transmitted most—yellow, green and blue, least—heat. The author concludes, in general (the source being a lamp), that the diathermancy is not proportional to the transparency ; and makes some general remarks on these results as related to those of Seebeck on prismatic dispersion. A supplement to the last paper was presented by the same author to the Academy, April 21, 1834, entitled ‘ New Re- searches on the immediate Transmission of Radiant Heat through different Solid and Liquid Bodies.”’ It is published in the Ann. de Chimie, lv. 337, and translated in Taylor’s Scien- tific Memoirs, Part I., p. 39. The author first investigates ‘‘the modifications which calo- rific transmission undergoes in consequence of the radiating source being changed.”’ He employs four sources of heat. 1. A Locatellilamp. 2. Incandescent platina. 3. Copper heated by flame to about 730° Fahrenheit. 4. Hot water in a blackened copper vessel. The heat from each of these sources was first compared as transmit- ted through plates of glass of different thicknesses, from *07 millims. to 8 millims. The results are given in a table, from which it appears that with copper and hot water the diminution of effect is rapid, with an increase of thickness in the screen; with water it is nothing beyond a thickness of 5 mm. A second ta- ble gives results for about 40 solid media of different kinds, of REPORT ON RADIANT HEAT. 5 the same thickness; most of them were wholly impervious to dark heat ; the most remarkable exceptions being fluate of lime and rock salt. In another table are the results with black glass and black mica; these substances, though diathermanous to the lamp and incandescent platina, are wholly impervious to the rays from hot water, and nearly so to those from heated copper. The discovery of.the entire diathermancy of rock salt has been before referred to, and has furnished the means of prose- cuting the author’s yet more remarkable researches on the RE- FRACTION OF Hear. Tothisimportant point M. Mellonidevotes a pertion ofthe same memoir. After a sketch of previous attempts to establish this property, he describes his successful experiment by concentra- ting to the focus of a rock-salt lens the rays of dark heat from hot copper and hot water. 4 similar lens of alum produced no effect; this proves that the effect is not due to the mere heat- ing of the central part of the lens. He next advances to the refraction of heat by a rock-salt prism ; describing an apparatus for the purpose. That the ef- fect is not due to secondary radiation, is shown by turning the prism on its axis into a different position, when no effect is roduced. He then discusses the “ properties of the calorific rays imme- diately transmitted by different bodies.’’ Under this head are detailed one of the most remarkable species of effects which the whole range of the subject presents. _The rays of the lamp were thrown upon screens of different substances in such a manner, that either by changing the di- stance, or by concentration with a mirror, or a lens of rock salt, the effect transmitted from all the screens was of a certain con- stant amount. This constant radiation was then intercepted by a plate of alum, and it was found that very different propor- tions of heat were transmitted by the alum in the different cases. This very singular result is established by numerous detailed experiments, of which a tabular statement is given, and the au- thor states it in the following terms: “‘the calorific rays issuing from the diaphanous screens are therefore of different qualities, and possess, if we may use the term, the diathermancy peculiar to each of the substances through which they have passed.” _ He next investigates the effects of different colours in glass on the absorption of heat. He infers in general that the colour- ing matter diminishes the power of transmission, and examines. the question, does it stop only rays of a definite refrangibility analogous to what happens in the absorption of light ? 6 REPORT—1840. With this view (following a similar mode of operation to that adopted in the last instance) he used successively glasses of different colours, for each of which the distance of the source was varied till a standard effect (about 40° deviation of the needle) was produced on the galvanometer. In this position, in each case, a plate of sulphate of lime was then interposed, and diminished the deviation to about 18° for all the coloured glasses except green, in which case it was to about 8°. When alum was substituted the deviations were reduced in the first case to 8°, in the second to 1°°6. Hence he concludes that all the co- loured glasses, except green, produce no “‘ elective action”’ on heat; green glass, on the contrary, transmits rays more easily stopped than the others. Connecting this with his other inference, that rays are stopped in proportion to their refrangibility, he instituted another series of experiments to put this to the test. The sources of heat compared were an argand lamp and incandescent platinum, the rays of heat from the former being the more refrangible. The quantities of heat from the lamp and the metal transmitted by the green glass were nearly equal; by all the others, nearly in the ratio of 2 to 1. Hence he infers that green glass is more diathermanous for rays of less refrangibility. Again, the rays transmitted by citric acid and some other substances, are those only of the greatest refrangibility. They should, therefore, be the least transmissible by green glass. This was found to be the case. Of 100 rays passed through citric acid, all the other glasses transmitted various preparations, from 89 to 28, while green glass transmitted only from 6 to 2. Without the citric acid, the rays from incandescent platinum were more copiously transmitted by the green glass than by the others. The whole of the rays of low refrangibility emitted by the platinum, and for which alone the green glass is transparent, had been stopped by the interposition of the plate of citric acid, which had, as it were, sifted it free from these rays. Hence the author concludes, that “ green glass is the only kind which possesses a COLOURATION for heat (if we may use the expression), the others acting upon it only as more or less transparent glass of uniform tint does upon light.” In a subsequent part of the memoir, M. Melloni gives a tabular view of the effects observed in the same manner, of the constant radiations emitted from six different substances, each intercepted successively by 24 minerals and 10 coloured glasses ; from which it appears that the transmission is very different, according to the nature of the first medium. REPORT ON RADIANT HEAT. yw ‘He afterwards describes an experiment with the solar rays transmitted by a green glass, and then intercepted by other media. They pass copiously through rock salt, but feebly through alum. Hence he concludes, that there are among the solar rays some which resemble those of terrestrial heat ; and in general, that “ the differences observed between solar and terrestrial heat, as to their properties of transmission, are therefore to be attributed merely to the mixture in different proportions of these several species of rays.”’ In a note to this memoir, M. Melloni refers to my original experiment (Phil. Trans. 1825), in which the action of the rays on surfaces is observed in connexion with their transmissi- bility. He confirms the accuracy of my result, by a careful repe- tition of the experiment with the thermo-multiplier, but makes no reference to the conclusion I had drawn, viz. the co- existence of two distinct sorts of heat in the radiation from luminous sources, one of which is the same as that from dark sources. He explains the result by supposing the transmitted rays to acquire, in and by the act of transmission through the glass screen, new properties in their relation to the surfaces on which they fall, 7. e. to the degree of absorption they undergo respectively on a black and a white surface. He extends the investigation by a table of results of the same kind with a series of screens, both transparent, and of various degrees of opacity. The ratio of the effects on the black and white surfaces is nearer to equality as the screen is more opake. On this subject there appears a short paper by M. Melloni in the London and Edinburgh Journal of Science, vol. vii. p- 475; to which I replied in the same journal, Jan. 1836. While referring to my own experiments, I may be allowed to add, that in Dr. Thomson’s Treatise on Heat, &c., first edition, the bearing of my investigation was incorrectly represented; and accordingly I pointed this out in the London and Edinburgh Journal of Science, Nov. 1830. In the second edition of Dr. Thomson’s work, which has lately appeared, the author omits all mention of the subject whatever. Transmission and Refraction of Heat: Forbes. The subjects of transmission and refraction of heat were taken up by Prof. Forbes; and Melloni’s experiments repeated and extended by him; the details being given in the first and part of the second sections of his first Memoir “on the Refraction 8 REPORT—1840. and Polarization of Heat,’’ read to the Royal Society of Edin- burgh, Jan. 5th and 19th, 1835, and published in their Trans- actions, vol. xiii.; also in the London and Edinburgh Journal of Science, vol. vi. The first section contains an account of various experiments with the thermo-multiplier. The principal object was to verify the several points already stated, and especially to determine the degree of accuracy of the instrument. From a comparison of its sensibility with that of air-thermometers, the author concludes that 1° of deviation of the needle corresponds to an effect indicated by about =,th of a centigrade degree, Without increasing the dimensions of the instrument, by which its sen- sibility would be impaired, he has been enabled, by the adapta- tion of a small telescope, readily to measure ;pth of its degrees ; that is, about >3,th of a centigrade degree. One of the most interesting points to which the author directed his attention, was the possibility of detecting heat in the moon’s rays. These rays, concentrated by a polyzonal lens of 32 inches diameter, and acting on the thermo-multiplier, gave no indication of any effect; so that Prof. Forbes con- siders it certain that, if there be any, it must be less than sonssoth of a centigrade degree. He repeated Melloni’s experiment of the refraction of heat by a rock-salt prism, and was enabled to obtain some approxi- mate quantitative results, giving the index of refraction for heat in this substance, which was a little less than that for light. In the course of his second section he describes further experiments relative to the question discussed by Melloni, of the separation of the effects due to heat and light, especially the peculiarity (before mentioned) attending green light: he tried flames variously coloured with salts—giving red, yellow, green, and blue light; but found the proportions of rays trans- mitted by alum, glass, and rock salt to be nearly constant for each substance. To this part of the subject Prof. Forbes again directed his attention, in a later series of experiments, in which ke has obtained numerical results of the highest value. These are detailed in the last part of his third series of Researches on Heat, read before the Royal Society of Edinburgh, April 16, 1838, and published in the Transactions of that body, vol. xiv. To the earlier portion of this memoir we shall refer, under another division of this report. The third section relates to the Index of refraction for heat of different kinds, as compared with that for light in the same REPORT ON RADIANT HEAT. 9 medium. The method of observation adopted is indirect, turn- ing upon the determination of the critical angle of total inter- nal reflexion. This was ascertained in a rock-salt prism, having two angles of 40°, and one of 100°. The sentient surface of the pile is so placed with regard to the prism, that it continually receives rays coming from the source of heat, after undergoing two refractions and one reflexion, whatever be the angle of incidence, which is effected by a very simple but ingenious mechanical construction. Every kind of precaution to avoid error was adopted. And in this way the author obtained a series of indices “ for the mean quality of the heat most abun- dantly contained in the rays obtained from various sources.”’ These values are given in a table, and are professedly but ap- proximate. Prof. Forbes has, however, subsequently favoured me with an unpublished communication, in which he states, that while the numbers may be regarded as relatively correct, in order to become absolutely so, they must all be reduced by about ‘05. This will give the corrected series of results as follows :— Index of refraction for Rock Salt. POC AAU ee ee ia te ee LOT Do. transmitted through alum. . . . 1°548 —_—- BIASS. aise vero LO ———-—--—— opake glass . . 1°543 eee on Sere Incandescent platina Dee RES ee a IH Do. transmitted by glass . . . . . 1°538 aS a a Opake mica... 1:534 (2 BIRSE STRIVE da ap le Soden aman aaiaarenimara F259 I Do. transmitted by clear mica . . . 1°527 PCTCUEY Be Abe Tee ae a a OD Source of Heat. Mean luminous rays . . . . . « « 1°552 From the experiments described in this section, the follow- ing general conclusions are deduced :— 1. The mean quality, or that of the more abundant propor- tion of the heat from different sources, varies within narrow limits of refrangibility. 2. These limits are very narrow indeed, where the direct heat of any source is employed. 3. All interposed media (including those impermeable to light), so far as tried, raise the index of refraction. 4. All the refrangibilities are inferior to that of the mean luminous rays. 10 REPORT-—-1840. 5. The limits of dispersion are open to further inquiry 3 but the dispersion in the case of sources of low temperature ap- pears to be smaller than in that from luminous sources. Reflexion of Heat: Melloni. A short paper, by M. Melloni, entitled ‘“ Note on the Reflexion of Heat,’”’ was read to the Royal Academy of Sciences, Nov. 2, 1835, and published in the Ann. de Chim. ix. 402, of which a translation appears in Taylor’s Sci. Memoirs, Part III. p. 383. After referring to the experiments of Leslie, to show that the reflexion of heat depends materially on the texture, polish, &c. of the reflecting surfaces, he proceeds to consider what takes place in diathermanous substances, as in rock salt ; where, there being no absorption, the difference of the heat trans- mitted gives the quantity reflected at the first and second sur- faces. With other media—as glass, rock crystal, &c.—very thin plates exercise no sensible absorption : hence heat, after traversing a thick plate, being intercepted by a very thin plate, the loss which this occasions is due solely to the two reflexions. These considerations afford the means of estimating the inten- sities of reflected heat from different substances; and the author, in conclusion, gives a comparative statement of the reflexions from rock crystal and copper. Analogies of Light and Heat: Melloni and Forbes. M. Melloni’s “ Observations and Experiments on the Theory of the identity of the Agents which produce Light and Heat,” were read to the Academy of Sciences, Dec. 21, 1835, pub- lished in the Ann. de Chimie, No. 50, p. 418, and translated in Taylor’s Scientific Memoirs, Part III. p. 388. In this paper the author combats the views of M. Ampére, who had proposed some ingenious speculations for explaining, on the theory of undulations, the identity of light and heat, the difference of effect being dependent solely on the different wave-lengths ; those producing heat being supposed longer than those giving rise to light. Athermanous media, such as water, intercept the longer waves, but not the shorter. Thus the aqueous humour of the eye prevents the retina from being affected by heat as well as light. The author admits that many phenomena may be sufficiently accounted for by the mere supposition of the difference of wave-lengths; but he mentions some experiments in which he thinks decisively that this will not hold good. The spectrum formed by a rock-salt prism gives the maxi- mum of heat considerably beyond the red end. On interposing REPORT ON RADIANT HEAT. 11 water of increasing thickness, the maximum successively occurs in the red, and thence upwards to the green. A similar effect is produced by colourless glasses; but with colowred glasses, whilst the Jwmtnous spectrum is variously absorbed and altered, the place of the maximum of heat remains unaltered, and the decrease from it quite regular. Another experiment consists in interposing a diaphanous body, which absorbs all the calorific, but only a part of the luminous rays. On using in this way a peculiar species of green glass coloured by oxide of copper, the greenish light transmitted “‘ exhibits no calorific action capable of being ren- dered perceptible by the most delicate thermoscopes, even when it is so concentrated by lenses as to rival the direct rays of the sun in brilliancy.” On these points Prof. Forbes has made some remarks in the London and Edinburgh Journal of Science, March, 1836. Such experiments as these, he justly observes, and indeed many more simple, clearly show that heat is not light, but nothing more. It is a question, then, what is the point really aimed at in these speculations. The author agrees with Mel- loni in the result, “ that one and the same undulation does not invariably impress the senses of sight and feeling at once. The great difficulty is this—to account for the equal refrangibility of two waves having different properties.” New Phenomena of Transmission: Melloni and Forbes. It appears by the Comptes Rendus, that on September 2nd, 1839, M. Arago communicated to the Academy of Sciences a letter by M. Melloni, containing some new and highly interest- ing experiments on the transmission of radiant heat. He found that rock salt acquires, by being smoked, the power of transmit- ting most easily heat of low temperature, or of that kind which is stopped in the greatest proportion by glass, alum, and (ac- cording to his view) all other substances. Upon this point, Prof. Forbes was led to some further con- siderations, and thence to fresh series of researches ‘* On the effect of the mechanical Textures of Screens on the immediate Transmission of Radiant Heat,’ an account of which he com- municated to the Royal Society of Edinburgh, Dec. 16, 1839. Upon the above-mentioned result of Melloni, Prof. Forbes remarks, that according to the conclusions indicated in his own Researches (third series), Melloni’s view of the interception of heat of low temperature by all substances alike, is equivalent to saying that substances in general allow only the more refrangi- ble rays to pass, or that while rock salt presents the analogy of white glass, by transmitting all rays in equal proportions, every 12 REPORT—1840. other substance hitherto examined acts on the calorific rays, as violet or blue glass does on light, absorbing the rays of least refrangibility, and transmitting only the others. And to this tule Melloni now makes out the first exception, or the first ana- logue of red glass, to be rock salt, having its surface smoked. Now Prof. Forbes, in his third series, had also pointed out another substance having the same property, viz. mica split by heat. In March, 1838, he had established, by repeated experi- ments, that the previous transmission of heat through glass, far from rendering it less easily absorbable by mica in this state, had a contrary effect ; and also that heat of low tempera- ture, wholly unaccompanied by light, was transmitted almost as freely as that from a lamp previously passed through glass. Mica not laminated possesses no such property; hence the effect is due to the peculiar mechanical condition of the sub- stance: and hence it occurred to the author, that the effect of smoking the rock salt was owing merely to a mechanical change in the surface ; he therefore proceeded to try the effects of sur- faces altered by mechanical means. The surface of rock salt being roughened by sand-paper, it transmitted non-luminous heat more copiously than luminous. Mica similarly scratched showed the same result. This effect is not attributable to differences in the proportions of heat reflected, for in this respect, at a polished surface, all kinds of heat are alike, as he had before shown; whilst by direct experiment, he found that, at least for the higher angles of incidence, reflexion is most copious from rough surfaces for heat of low temperature, or the same kind which is most freely transmitted ; proving incontestably, that the stifling action of rough surfaces is the true cause of the inequality. That there is a real modification of the heat in passing through a roughened surface, as well as through laminated mica, and the smoky film, appears from some direct experiments on heat sifted by these different media; which, when transmitted by any one of these, is found in a fitter state to pass through each of the others ; and this modification is the more perceptible as the cha- racter of the heat is more removed from that which these media transmit more readily ; that is, as the temperature of the source is higher. The following results were stated :— Heat from lamp through Rays out of 100 smoked rock salt. transmitted. Pirectinge 5020s cement tis oo) codes eee Previously sifted by another plate of smoked rock salt. 44 do. do. laminated mica . 44 do. do. roughened salt . 403 REPORT ON RADIANT HEAT. 13 The author then proceeded to try the effect of fine wire gauze and fine gratings of cotton thread ; but no difference could be de- tected corresponding to the different kinds of heat ; in every case the interception was proportioned to the fineness of the gauze. When fine powders were strewed between plates of rock-salt, or fine lines were ruled upon the surface, or the surface tar- nished by mere exposure to the air, the easier transmission of heat of low temperature was rendered apparent. These effects the author considers as evidently pointing to phenomena in heat, resembling diffraction and periodic co- lours in light. Such was the general sketch of his researches which Prof. Forbes gave at the period above-mentioned. Subsequently (up to March 1840) he continued engaged on the same subjects, and on May 15, 1840, laid before the council of the Royal So- ciety, Edinburgh, a more extended account of the entire inves- tigations, which appears in vol. xv. Part I. of their Transac- tions, under the title of ‘*A Fourth Series of Researches on Heat.”’ Some remarks by M. Melloni appear in the Comptes Rendus, March 30, 1840, on the same subject. For obtaining a general view of these results, the main point to be kept in sight is the relation which the transmissibility of each sort of heat appears to bear to its refrangibility ; and hence the analogy of diathermanous media, which transmit the less re- frangible heat, to transparent media, which transmit the red rays of light, the transmission of the more refrangible heat being analogous to that of violet light. Upon this important point Prof. Forbes enlarges in the in- troductory part of his memoir; he justly observes that such a generalization carries us forward a step, by teaching us to refer to the quality of refrangibility certain properties of heat, which before were connected only with certain vague characters in the nature of the source whence it was derived. Among other things, we find, what was long suspected, but what Melloni first conclusively proved, that it does not essentially depend on the presence or absence of light. This refers to his singular dis- covery of the change produced by the intervention of certain screens. Heat from any source, if it admit of transmission at all through glass, alum, or water, will ultimately have the character of glass-heat, alum-heat, or water-heat, just as light from the sun, or from a candle, becomes red, blue, or green, by trans- mission through glasses of those colours. The author gives, as an illustration, the following scale of different kinds of heat, in the order of refrangibility, beginning with the lowest :— 14 REPORT—1840. 1. Heat from ice. 2. ———— the hand. 3. ———— boiling water. 4. — avesselof mercury underits boiling temperature. 5. ————— metal smoked ;—wholly non-luminous in the dark, heated by an alcohol-lamp behind it. 6. Heat from incandescent platina (over a spirit-lamp). : an oil-lamp (direct). 8. Otl-lamp heat transmitted by common mica. a glass (argand lamp). 10. ——_—__——_———————-. citric acid. Vl. —_—_ —_——— alum. 12. ———— ice. Melloni having shown that a portion of the heat from a lumi- nous source is transmitted through certain screens, which are wholly opake to light, it became natural to inquire whether the rays so passed possessed the properties of heat from dark sources. This he found to be partly the case, and partly not. The direct test of examining the refrangibility of the heat- rays issuing from the screen occurred to Prof. Forbes, who found that opake glass and mica act as clear glass and mica do in ele- vating the mean refrangihbility of the transmitted heat, an ac- tion analogous to that of yellow glass upon light. (See 3rd Series, Art. 73, 81, &c.) But in all this there was nothing exactly equivalent to the action of red glass; this, however, was discovered by Melloni, by the happy suggestion of covering the surface of rock salt with smoke. These remarks introduce more clearly the main object of Prof. Forbes in following up the inquiry. In the present paper the details of many series of experiments are given, and the more precise results now established may be stated as follows : I. The peculiar character of the film of smoke on the surface of a diathermanous medium, analogous to redness in glass for light, was found to be possessed by—1. The simple powder of char- coal. 2. Some other dull earthy powders. 3. Surfaces simply dull, or devoid of polish. 4. Surfaces irregularly furrowed, as with emery or sand-paper. 5. Polished surfaces, on which fine distinct lines have been drawn. 6. Transparent mica, when mechanically laminated, which, as a continuous medium, pos- sesses opposite properties. I]. All kinds of heat (i.e. of all refrangibilities) seem affect- ed indifferently by the following media :— 1. The thinnest leaf-gold, which is impervious to any kind of heat. 2. Fine metallic gratings, which transmit all kinds of heat — _ —— REPORT ON RADIANT HEAT. 15 in a proportion probably exactly that of the areas of their inter- stices. 3. Thread gratings. 4. Most crystalline bodies in a state of powder, in which case they approximate to a condition of opacity for heat. Ill. The following substances, in addition to those before known, transmit most heat of high temperature or high refran- gibility, analogous to violet light :— 1. Several pure metallic powders. 2. Rock salt, in powder, and many other powders. 3. Animal membrane. IV. Heat of low temperature is most regularly reflected at imperfectly polished surfaces. It is also, as has been shown above, most regularly transmitted. These facts are in them- selves very remarkable, and especially so with reference to the theory of heat, and its analogies to that of light, particularly with respect to absorption. Some of these considerations, which bear on the undulatory doctrine, are noticed by the author in 24, : The curious question relative to the analogies of the action of gratings, &c., to the parallel cases in the interference of light, has been recently illustrated by some mathematical in- vestigations by Professor Kelland ; and the author concludes his memoir with some highly ingenious and interesting suggestions for further inquiry bearing on these topics. Radiation of Heat : Hudson. At the meeting of the British Association, 1835, Dr. Hudson, of Dublin, communicated some researches on radiant heat, of which notices appear in the Report of that Meeting (p.163, and Proceedings of Sections, p.9.). A paper by the same author on the subject is printed also in the London and Edinburgh Jour- nal of Science, vol. viii. p. 109. In the paper last mentioned, besides making some critical re- marks on the results of Melloni and others, the author describes a very simple and effective mode of arranging the apparatus for experiments on diathermancy with the thermo-multiplier, so as completely to exclude the influence of secondary radiation. The source of heat is a canister of hot water, which can be so placed in two different positions that it is exactly at the same distance, and presents the same surface ; but in one case the pile receives the heat both direct and secondary; in the other only the se- condary, derived from the heating of the screen. In his communication to the British Association the same author examines principally certain questions bearing on the supposed radiation of cold, and the theory of Leslie. These 16 REPORT—1840. were performed by a differential thermometer, and a concave reflector, with a hollow back, so that the mirror itself could be heated to any required point, by filling the hollow with hot water. The source of heat was a canister of water, with one surface varnished, another metallic. The main results were as follows :— 1. The mirror being at the temperature of the air, and the canister cooled below it, the varnished side produced a greater cooling effect on the focal bulb than the plain, in the same ratio as that in which it produced a greater heating effect when the canister was heated whove the air. 2. The mirror being heated to 200° Fahrenheit, and the ca- nister at the temperature of the air, both bulbs were so placed as to be equally affected by the heat of the mirror; when the ca- nister displayed a cooling effect, the varnished side being the most efficacious. 3. Again, with the same conditions, except that the canister was heated 10° or 12° above the air, it was placed at different distances ; at near distances it showed a cooling effect ; at a cer- tain point this ceased, and beyond it, it began to produce a slight heating effect. 4, Some attempts were made to try the effects while the bulb was kept cool by evaporation; the canister being also cooled below the air, the cooling of the bulb was increased beyond what took place when the canister was at the temperature of the air. These experiments were confessedly imperfect, from the difficulty of regulating the evaporation. The author considers them as favourable to the theory of the radiation of cold; he also refers to them as in some degree con= firmatory of Leslie’s view of pulsation. The most remarkable result is that of Case 2; it seems to prove that a mirror, when heated, will still reflect rays of heat, thrown upon it from a source of much lower temperature. The results are viewed by the author as supporting the theory of the radiation of cold. I believe the doctrines of that theory may in all cases be equally well expressed in other language, in conformity with the view to which I referred in my former re- port, p. 262. Dr. Hudson has speculated with much ingenuity on another point of great interest, the different radiating powers of different surfaces. Understanding by the surface a certain physical thickness, he conceives the radiating power to depend on the capacity for heat of the substance of the lamina, which seems perfectly conformable to the general law of the equilibrium of temperature. REPORT ON RADIANT HEAT. 17 Influence of surfuce and colour on Radiation : Stark and Bache. The influence of the colour of a surface on its powers for absorbing and radiating heat, is a question which has long attracted notice, and has often been involved in no small con- fusion, from false analogies. The sun’s rays, and, in general, what is called luminous heat, are absorbed by surfaces (ceteris paribus) in proportion to the darkness of their colours ; but it has been too hastily assumed that the same would hold good with non-luminous heat, and still more groundlessly, that the colour would influence the rudiating power of the surface ; the texture of the surface, however, is known to exert a powerful influence. These distinctions are fully insisted on in my former report. Since that period, however, the subject has been taken up by Dr. Stark, who, in an elaborate paper in the Phil. Trans. for 1833, details a number of ingenious experiments, which he con- ceives support the doctrine of the influence of colour, not only on the absorption of dark heat, but even on odours, miasma, &c. The object of the present report is not controversial ; I will therefore merely state, that I discussed in detail Dr. Stark’s reasonings, in a paper published in the Edinburgh New Philo- sophical Journal, October, 1834, where, though allowing the value and accuracy of the experiments, I have expressed my objections to the inferences made from them. It appears in general that the texture and nature of the sur- face most unquestionably exert a great influence. Now, where- ever there is a difference in the colour, there must be either a difference in the mechanical structure of the surface, or some new matter added or abstracted. When therefore we consider the changes which thus occur, we cannot infer that the effect is not owing to these instead of to colour as such. The ques- tion, however, is a highly curious one, and worthy the most accurate investigation. Having in some measure called attention to it in my former report, it was with no small gratification that I found the sub- ject had excited interest not only in this country, but also in America ; and to Professor Bache (since appointed principal of Girard College) we owe by far the most extensive and valuable series of experiments on this important but difficult point of inquiry : they are given at length in the Journal of the Franklin Institute, November, 1835. The notices of these experiments which had been pub- lished in this country, not appearing to convey adequate notions of their nature or value, I endeavoured to bring them VOL. 1x. 1840. Cc 18 REPORT—1840. more prominently forward by some remarks in the Physical Section of the British Association at Liverpool in 1837*. In my former report I had thrown out some suggestions both as to the want of such a series of experiments, and as to the fundamental difficulty arising from the variety of causes which must influence the results; but more especially the differences of thickness in the coatings, which in the ordinary mode of operating could not be estimated, yet must greatly modify the effects. With reference to the necessity of equalizing the coatings, Mr. Bache refers to an important observation of Leslie, viz. that radiation takes place not merely from the actual surface, but from a certain depth, or lamina of the surface, the thickness of which is quite appreciable in good radiators, and differs for different substances. Proceeding upon this fact, the author justly observes, that ** the radiating powers of substances would not be rightly com- pared by equalizing their thicknesses upona given surface, nor by equalizing their weight; but by ascertaining for each sub- stance that thickness beyond which radiation does not take place.” It is then on the original application of this fundamental idea that his whole series of experiments is conducted. Upon this principle the first object was to obtain some data as to thicknesses of different pigments necessary to be employed. The method adopted throughout was to employ tin cylinders of the same size, filled with hot water, and having thermome- ters inserted through a hole in the top; while their surfaces were coated with the different substances under trial. The ra- diation was estimated by the observed rates of cooling. To find the critical thickness of the coating just spoken of, the time of cooling a certain number of degrees was accurately observed, first with a thin coating, then with an additional layer of the pigment, and so on, until it was found that addi- tional thickness did not increase the rate of radiation, but began to diminish it; thus each coating was adjusted precisely to that thickness at which it produced its maximum effect. Every precaution to ensure accuracy appears to have been most diligently taken, and several series of preliminary experiments are recorded for the purpose of ascertaining the limits within which the precision of the results may be relied on. A standard cylinder, coated with aurum musivum (as being found not liable to tarnish or alteration), was used inall the experiments, and the effect of each coating compared with this under similar circumstances. * See Report, 1837. Sectional Proccedings, p. 20. REPORT ON RADIANT HEAT. 19 The results of different sets of experiments are given in the tabular form, and apply to coatings of a great variety of sub- stances differing in their chemical nature, as well as in rough- ness, texture and colour. The following table is extracted as fully exhibiting the general result of all the experiments; the substances being arranged in the order of their radiating powers, beginning with the highest. Nature of Coating. Colour. Surface. Litmus blue. Blue. Prussian blue. Blue. Rough. Ammon. sulphate Greenish blue Rough of copper. : SM Peroxide of manga- Brothiat black. ie ot shining, but nese. uniform, India ink. Black. Not smooth. ‘ @Streaked: Bichromate of potash. Brown. si thn chteales India ink. Black. Smooth. Alkanet. Crimson. Not shining, bu uniform. Carb. of lead in oil White. Smooth, not of lavender. shining. Sulphuret of lead. Black. Alkanet blue. Blue. Carb. magnesia. White. Rough. Carb. lead in gum. White. Smooth. Carb. of lime. Dingy white. Medium. Vermilion. Red. Smooth. Sulph. baryta. White bluish. Rough. Golden sulphuret of B Smooth, in é rown. antimony. streaks. Indigo. Blue. Smooth. -Cochineal. Crimson. Smooth. Red lead. Orange. Smooth. Sulph. baryta. White. _Medium. ‘ Plumbago. Black. Bre ven tp ; but uniform. -Chrom. lead. Yellow. Smooth, ‘ . Smooth, in Gamboge. Olive green. ays Se _Bisulphuret of tin. Yellow. Smooth. c2- 20 REPORT— 1840. It thus distinctly appears, that through so extensive and varied a range of differences in the state of the radiating sur- face, no determinate relation subsists between the radiating power, end either darkness of colowr, or any other distinctive character of the coating employed; not even its roughness or smoothness. Repulsive Power of Heat: Powell. Closely connected with the radiation of heat is its property of exerting or exciting a repulsive force between particles or masses of matter at small though sensible distances. Such a property was first announced by Libri in 1824; and was further examined by Fresnel (dun. de Chim., xxix. 57. 107.) and Saigey (Bull. Meth., xi. 167.), but their results seem to have been open to some doubt. A new interest attached to the subject from the reference made to this property by Prof. Forbes (in a paper read to the Royal Society of Edinburgh, March,1833, and since published in their Transactions, vol. xii.) in explanation of certain vibra- tions of heated metals first observed by Mr. Trevelyan. A paper from me was read to the Royal Society, June 19,1834, and printed in the Philosophical Transactions, 1834, Part II. containing an account of experiments on a different principle from any of the preceding, which appeared to furnish a deci- sive proof of the fact of repulsion. The essential principle is the employment of the colours of thin plates, as a measure of the separation produced between two surfaces, by the repulsive action of heat applied to one of them. I also made observations on several particulars attending the mode of action, both in that paper, and in a communication to the British Association at the Edinburgh meeting*. Formation of Ice: Farquharson. An interesting case, in which the principles of the theory of radiant heat are related to the explanation of natural phenomena, occurs in the instance of the formation of ice exclusively at the surface of still water, but occasionally at the bottom of running water. This point excited attention some years ago, and was par- tially discussed by Mr. Knight in the Philosophical Transactions, 1816. Mr. MacKeevor and Mr. Kisdale subsequently investi- gated the theory, and M. Arago gave a discussion of the whole question in the Annuaire, 1833, and in the Edinburgh New Phi- losophical Journal, vol. xv. p. 128 ; lastly, a highly curious paper appeared in the Philosophical Transactions for 1835, Part II. * See Report, 1834, p. 549, and Dr. Thomson’s Records of Science. REPORT ON RADIANT HEAT. aM © On the ice formed under peculiar circumstances at the bottom of running water’, by the Rev. J. Farquharson, F.R.S. of Al- ford, Aberdeenshire. In this paper the author details various new and highly interesting particulars as to the mode of the formation of the spongy masses of spiculz of ice at the bottom of certain rivers in his neighbourhood, and the peculiar cir- cumstances under which alone it is formed. He examines acutely the several explanations which have been suggested, which he shows are all insufficient to explain the whole of the circum - stances, and then proceeds to suggest his own theory, which is grounded essentially on the assumption that the radiation of heat from substances at the bottom goes on through the water ; and partly also on the supposed greater radiation from dark- coloured surfaces. Neither of these assumptions, it appears to me, are admissible ; the former especially is directly at variance with the experiments of Melloni. Some suggestions at least towards a theory not open to these objections, are given by an anonymous writer in the Magazine of Popular Science, vol. i. p- 157. Division [I].—Pouarizep HEAT. Polarization of Heat: Forbes. The original statement by Berard, of the polarization of heat by reflexion, and the attempts to verify it, are mentioned in my former report*. In 1833, Melloni tried to repeat the experiment with tourmalines, but unsuccessfully+. In 1834, Nobili attempted it by reflexion, employing the thermo-multiplier, but without success t. The disbelief in such aresult, at least with dark heat, seems now to have prevailed generally. Mrs. Somerville, in the second edition of her “‘ Con- nexion of the Sciences ’’ (in 1833), speaks of it as altogether without experimental proof. Prof. Forbes took up the inquiry in November, 1834; and in his first memoir, already referred to in Section 2, announced his complete success, after having in the first instance failed from ee influence of secondary radiation, which disguised the real effect. (1.) He proved distinctly the stoppage of a considerable pro- portion of heat when the tourmalines were crossed, not only with a lamp, but with brass heated below luminosity. (2.) In the third section of the same memoir, he details his * British Association Report, vol. i. pp. 262. 276. + Second Memoir, dnn.de Chim. 55. Taylor’s Scientific Memoirs, Part I, p. 59. t Biblioth. Univ., Sept. 1834. 22 REPORT—1840., researches on the polarization of heat by refraction and re- flexion. In the former he employed piles of mica, and through these, found even dark heat very freely transmitted at the polarizing angle. Without (in this stage of the inquiry) aiming at quantitative results, he found in general that the pro- portion of heat polarized varied with the source in the following order, begining with the highest :— Argand lamp. Locatelli lamp. Spirit lamp. Incandescent platina. Hot brass, about 700° Fahrenheit. Mercury, 500° in crucible. Water under 200°. (3.) The polarization of heat by reflexion at the surface of a pile of plates of mica was also established; and with regard to the reflexion from glass, Prof. Forbes has also remarked,that from the known proportions of heat reflected, the quantity, even at the maximum which would reach the thermoscope after two reflexions, would be so extremely small, that no difference of effect in the two rectangular positions could really have been perceptible in the form of the experiment adopted by Berard. (4.) In the fourth section the author enters on the modifications which polarized heat undergoes by the intervention of crystal- lized plates between the polarizing and analysing parts of the apparatus ; an inquiry suggested by the obvious analogy in the case of light. In the crossed position, when polarized heat is stopped (if the analogy hold good), the intervention of a plate of double refracting crystal would restore the effect. This apparently paradoxical result was fully verified with plates of mica, and subsequently with selenite and other substances, not only in the case of luminous sources, but even with water be- low the boiling temperature. Of 157 experiments with three different mica plates, only one gave a neutral and one a negative result. Of these 157, 92 were made with heat below luminosity. The apparent paradox was increased by the circumstance that a thin plate of mica which “‘ depolarized’ but feebly seemed to stop more heat than a thick plate which depolarized more completely. The main fact was ascertained for the first time on Decem- ber 16, 1834. The Professor justly censures the use of the term “‘ depolarize,”’ and suggests ‘‘ dipolarize”’ as preferable. (5.) From the result thus unequivocally established, a train of highly curious consequences follow. We have hence, as direct corollaries, the dowble refraction of the rays of heat by REPORT ON RADIANT HEAT. 293 the mica, and their interference according to the same laws as those of light. Hence also follow the constancy of the sum of the intensities of the rays in the rectangular positions, or their complementary character, agreeably to the formulas of Fresnel for light. This again involves their retardation, ac- cording to the well-known principles of the undulatory theory ; and hence from Fresnel’s formulas we are assured theoretically of the existence of circular and elliptic polarization in the rays of heat, under the appropriate conditions: we have thus also the means of deducing the length of a wave of heat. The whole of this most important series of investigations was completed between November 1834 and January 1835, and their originality and priority are thus placed beyond dispute. The main practical improvement (which led to all the rest of the discoveries) was the employment cf the piles of mica for polarizing the heat. In the summer of 1835, Prof. Forbes was at Paris; and finding both M. Biot and M. Melloni sceptical as to his results, he exhibited them with mica piles, which he himself prepared on the occasion, and which he left in M. Mel- loni’s hands. In these experiments the utmost care was taken to guard against all the sources of fallacy from secondary radiation, &c. ; but as Prof. Forbes observed, these always tended to disguise and not to exaggerate the results. One consideration of this kind arising from the mere mathematical question of the dif- ferent amount of heat which might be radiated from one pile to the other in the two rectangular positions (regarded merely as a mathematical problem), was proposed by myself at the Dublin meeting of the British Association, 1835, but was completely shown to be inapplicable as a practical objection by Prof.Forbes, in a short paper in the London and Edinburgh Journal of Sci- ence, November, 1835 ; and further by direct experiment de- scribed in the same Journal for March, 1836. Circular and Elliptical Polarization of Heat: Forbes. On the Ist of Feb. 1836, Prof. Forbes announced to the Royal Society of Edinburgh, that he had that day succeeded in esta- blishing the circular polarization of heat, even when unaccom- panied by light, by direct experiment. It has been already noticed, that theoretically this would follow from the laws of depolarization. But in the present instance, Prof. Forbes, fol- lowing up the analogies of Fresnel with regard to the internal reflexion of light, found the very same thing verified with heat by similar internal reflexion in a rhomb of rock salt, where the 24 REPORT—18-0. plane of reflexion is inclined 45° to the plane of primitive polarization. A short notice of this discovery appears in a paper by the author, in the London and Edinburgh Journal of Science, March, 1836, in which he also states the inference from the same considerations, that the waves are of the same kind as those of light, viz. formed by transverse vibrations. In a paper reported in the Proceedings of the Royal Society of Edinburgh, March 21, 1836, and printed along with the second series of Prof. Forbes’s Researches in the London and Edinburgh Journal of Science, vol. xii., that philosopher de- scribes some additional results which he has obtained respect- ing the polarization of heat. These are briefly as follows :— 1st. Heat polarized in any plane, and then reflected from the surface of a refracting medium, changes its plane of polariza- tion in a manner similar to what obtains in light ; that is, the plane is on one side of the plane of reflexion up to the maxi-~ mum polarizing angle, and on the other side after passing that limit. This mode of determining the polarizing angle offers some advantages over the more direct methods. 2ndly. Metals polarize heat very feebly by reflexion. Yet the effect is perceptible, and increases, through a considerable range of incidences, but it does not seem to attain a maxi- mum; in this respect it seems to agree with what Sir D. Brewster has remarked in light, viz. that the maximum is greatest for the least refrangible rays, heat being less refrangible than light. 3rdly. Heat polarized in a plane inclined 45° to the plane of reflexion at silver, has its nature changed, as in light, and pre- sents the conditions of elliptic polarization, though the ellipse is much more elongated. 4thly. Two reflexions from silver increase the polarizing effect of metals, and an increased tendency to circular polariza- tion under the conditions of the last case. The effect increases with the obliquity of incidence. All these results have been verified in the case of obscure as well as luminous sources of heat. On the 15th Feb. 1836, the Keith prize was awarded to Prof. Forbes by the Royal Society of Edinburgh; the Vice- President, Dr. Hope, stating, in the course of a most able address delivered on the occasion, that several members of the council, as well as himself, had personally witnessed the satis- factory verification of the main facts announced, before the medal was adjudged. REPORT ON RADIANT HEAT. 25 Polarization of Heat from different sources: Melloni. M. Melloni’s first memoir ‘ On the Polarization of Heat,”’ was read to the Academy of Sciences in Jan. 1836; it appears in the Ann. de Chim. |xi. April, 1836 ; and is translated in Tay- lor’s Scientific Memoirs, Part II. p. 325. The author commences with a fair review of the previous in- vestigations on the subject, admitting Prof. Forbes’s discovery, but remarking the very small amount of the effect in the case of obscure heat. He adopts the supposition, that “‘ the different temperatures of the calorific rays are to radiant heat what the different colours of the luminous rays are to light.’’ The latter, he observes, are all equally polarizable, and thus he is led to regard the difference of polarizability in the rays of heat as rather apparent than real. His object then, in this memoir, is to examine the question of the reality of the polarization of heat, and of the equality of the effect in different sorts of heat. After some considerations on the general nature of the appa- ratus to be employed, and overcoming the difficulty arising from the small total intensity of the rays, by concentrating them by means of a rock-salt lens, he proceeds to detail his several series of experiments, the results of which he gives in the form of tables :— Table I. gives the different indices of polarization obtained with nine sorts of tourmalines of different colour, the source of heat being a locatelli lamp. He then tried the experiment, taking that pair of tourmalines which gave the greatest effect in the last set, with plates of various substances interposed between the lamp and the appa- ratus. Of these, opake black glass rendered the effect nearly insensible ; other solids and liquids of various degrees of trans- parency produced effects of different magnitude. In Table II. these results are registered, and the properties of the media, in this respect, were found to follow the same pro- portion as their diathermancy. The author considers the difference of the tourmalines in this respect as referrible to the same cause. Table III. gives similar results with another pair of tourma- lines, in which case the proportions are found to differ. In Table IV. are given the indices of polarization with four different pairs of tourmalines, each employed with different sources of heat; viz. the locatelli lamp, argand lamp, incan- descent platina, and copper at 400°. The effect in the latter Case was very small. 26 REPORT—1 840. In recapitulating his views, the author refers to the wnequal absorption of the two pencils in different tourmalines, as cau- sing the differences observed. A further paper by the same author, on Tourmaline, &c., in the dnn. de Chim., April, 1836, displays much ingenuity, but nothing of peculiar novelty or fundamental importance. From the Comptes Rendus, 1836, i. 194, it appears, that on the 15th Feb. 1836, M. Arago communicated to the Aca- demy of Sciences a letter from Prof. Forbes, announcing his discovery of the circular polarization of heat of the rock-salt rhomb. At the next meeting of the same body (Feb. 22), MM. Biot and Melloni stated, that in following up Prof. Forbes’s experi- ment, they had found that quartz possessed the same “‘rotative”’ quality for heat as for light. Dr. Thomson, in the second edition of his Treatise on Heat, &c. (1840), while giving an outline of the discoveries of Forbes and Melloni, has by no means clearly distinguished the share borne by each of those philosophers in the investigation. In particular, with respect to the fact of polarization, he has not given Prof. Forbes the credit so unquestionably due to him for the priority of the discovery. He observes (p. 139), ‘ In the earlier experiments of Melloni, he did not find that the rays of heat were polarized when passed through the tourmaline. But he afterwards found that this conclusion was hasty, and that the tourmaline polarizes heat as well as light. The truth of this statement is shown very clearly by Prof. Forbes. They also polarized heat by plates of mica, and also by reflexion,”’ &c. These expressions certainly assign the priority to Melloni, as well as an equal share in the subsequent results ; both of which we have seen are greatly at variance with the truth. Further Researches: Forbes. Prof. Forbes’s second series of Researches on Heat was read to the Royal Society of Edinburgh, May 2, 1836, and printed both in the Edinburgh Transactions, vol. xiii., and in the London and Edinburgh Journal of Science, vol. xii. 1838. The author remarks at the outset, that in his former memoir he had confined himself to the establishment of the general facts of the polarization and dipolarization of heat, without pre- tending to accurate quantitative results ; he now proceeds, there- fore, to a more detailed investigation of the subject, with a view to more precise numerical determinations. The first section relates to the methods of observation em- ployed, and the examination of the values of the degrees of the REPORT ON RADIANT HEAT. 27 galvanometer, which, for the most part, do not indicate equal increments of force. Two tables are given. By the first, the statical deviations of the needle are reduced, so as to be mea- sures of the force producing them; by the second, the dynami- cal effect, or arc, moved over by the initial disturbing action, is reduced to the final or statical effect, and thence to the true measure of heat. Several peculiarities attendant on the use of the galvanometer are likewise discussed. In section 2, the observations formerly published on the polarizing action of tourmaline are confirmed, including the case where heat, entirely unaccompanied by light, was em- ployed. In this case, the author allows, the greatest difficulty was to be encountered. The third section treats of the laws of the polarization of heat by refraction or transmission. Prof. Forbes expressly observes, that his former results were not held out as numeri- cally precise ; and with reference to Melloni’s conclusion, “ that all kinds of heat are equally polarizable at the same incidence,” he confirms his former view of the incorrectness of this infer- ence by a great number of experiments, which show that the heat from non-luminous sources is less polarizable by a given plate of mica, at a given angle of incidence, than that accom- panied by light. These experiments were performed with plates of mica, pre- pared in a way discovered by himself, to which reference is made (though without describing the process), in a paper before quoted in the London and Edinburgh Journal of Science, March, 1836. The method consists in applying sudden heat to a thick plate of mica, which splits into an infinity of extremely thin films, so thin as to be incapable of retaining heat; these form polarizing piles of great energy. With one pair of such plates the author obtained the following per centages of heat stopped, when the planes of refraction of the two plates were in the rectangular position :-— Source of Heat. Rays out of 100 Polarized. Parma VOM | Fil) he) ps.) me - (2to 74 Incandescent platina . . . . . . 72 Brass about 700° . . . Baresi Do. with glass screen. . . . . . 72 Mercury in crucible at 410° . . . 48 Bae, SAME oe) toy eaves rience ny A These observations were repeatedly made, and verified by others with other pairs of plates. The results agree with the analogy of light ; those lowest in the scale being the cases of the least refrangible rays. 28 REPORT—1840. In the fourth section the law of polarization by reflexion is discussed. A number of reflecting surfaces were tried, and split mica was preferred. The amount of polarization by re- flexion at a given angle, is shown to vary with the source of heat ; and it is probable that the kinds of heat do not rank in the same order when the angle is changed. This is the case with light. The change of the plane of polarization by subse- quent reflexion, is similar to that which occurs when light is used. The circular polarization of heat by total internal reflexion, is discussed in the fifth section. This, as before remarked, is a phanomenon really produced in the experiments on dipolari- zation, if the mica be of a suitable thickness. The direct ex- periment with rhombs of rock salt, has been already mentioned also. The author here gives a detailed account of them, and . the laws of the phenomena deducible, in which the precise analogy with those of light is preserved. Equal Polarizability of Heat from different sources : Melloni. Melloni’s second memoir on the Polarization of Heat appears to be founded on the second part of his communication to the Royal Academy of Sciences in January, 1836. It is printed in the Ann. de Chim. lxv. May, 1837, and the translation in Tay- lor’s Scientific Memoirs, Part VI. The principal points of these extensive researches may be reduced to the following heads :— (1.) Referring to Prof. Forbes’s Researches, first series, Mel- loni. contends that the differences of polarizability in the heat from different sources there exhibited, are in fact due to differ- ences of secondary radiation from the heating of the mica piles, and subsequently appeals to Forbes’s second series, in which he conceives the approach to equality is much nearer, as this source of error was more avoided. At lower temperatures of the source, he observes, that mica _ transmits less heat in proportion, and therefore absorbs more : thus the secondary radiation is greater, and the apparent dif- ference in the two positions, or index of polarization, is less. (2.) He remarks, that Prof. Forbes had found the heat from a dark source, after transmission through glass, to become as po- larizable as that from incandescent platina; whereas he considers that the glass plate absorbed the greater part of those rays which otherwise would have heated the piles, and that thus the apparent polarization was increased. (3.) Melloni describes his apparatus, and the precautions for REPORT ON RADIANT HEAT. 29 avoiding secondary radiation, &c., employing piles of split mica, and throwing parallel rays on them by means of a rock- salt lens, having its principal focus at the source of heat. He then enters upon the details of his results, in several series, with piles of different numbers of lamine, and at dif- ferent inclinations to the axis (the source of heat being a lamp), giving in each case the calorific transmissions in the rectangular positions, or proportions of heat polarized. These are com- prised in a series of eight tables, from which the author derives the following conclusions :— I. The proportion of heat polarized increases as the inclina- tion of the piles is diminished. II. It attains a maximum at a certain inclination. III. This inclination is greater as the number of lamine is increased. He points out the close agreement of these results with the phenomena of light according to Brewster and Biot. (4.) The author pursues a further series of experiments on polarization by reflexion, and arrives at the conclusion that the angle of complete polarization by refiexion is very nearly the same for light and for heat. (5.) If any diathermanous substance be interposed between the luminous source and the piles, the index of polarization does not vary with the substance employed. This, he contends, proves that the nature of the heat does not alter its polarizability. But also from direct experiment with the radiations from different sources, he makes the same inference, employing, in- stead of a lamp, incandescent platina, metal heated to 400°, or boiling water, with the same results of uniform polarizability. He maintains that the difference of polarizability by refrac- tion, arising from the different refrangibility of the rays of heat, is too minute to be sensible. And for all experiments on obscure heat he proposes to sub- stitute as the source a black glass heated by flame. (6.) On the depolarization he refers to Forbes’s experiments, in which he contends the difference in the rectangular position is very small, but nearly equal with different sources. He repeats the experiment, with black glass interposed, and finds the effects much greater, and nearly equal in the different cases. He endeavours to explain Forbes’s result of the difference with different sources, by secondary radiation. Further, by the same method (of interposing a black glass), he finds the equal depolarizability of every kind of heat. 30 REPORT—1840. In an attempt to pursue the analogy of the tints of depolar- ized light, he acknowledges a failure, and thence considers the interference of calorific rays as not yet proved. Upon these investigations the following remarks may be offered :— Under the first head, it should be recollected that Prof. Forbes’s first memoir, was avowedly only directed to ascertain general facts, not numerical values; while, with regard to the more precise results of the second memoir, it would appear from the details there given, that the secondary radiation could not affect the results. The screen between the source and the piles was removed only during the few seconds required for observing the first or impulsive arc of vibration, the time of which was wholly insufficient for the conduction of heat; besides, such an effect was disproved by direct experiment, as mentioned above (p. 23). 3 Of the second point, we shall presently have to notice a com- plete investigation by Prof. Forbes. As to the third, with this construction, the heat absorbed by the mica was very trifling; but by the more improved process since used by Prof. Forbes, (p. 27), we have seen this source of error is wholly got rid of. The employment of a pencil of parallel rays does not seem, upon consideration, materially to increase the intensity. The fourth point is no more than what had been already established by Prof. Forbes. With respect to the fifth head (including the most important part of these researches), it must be observed, that the differ- ences in the nature of the heat obtained by the intervention of diathermanous substances, are not the same as those between heat from luminous and dark sources. And further, in the experi- ments mentioned with radiations from different sources, no numerical results are stated. On this point we shall presently notice some more detailed researches of Prof. Forbes. The sixth point, on the subject of depolarization, is confess- edly one of the most delicate in the whole inquiry; but for the same reasons as before, the effect of secondary radiation cannot be referred to as capable of having produced the differences observed. Unequal Polarizability of Heat from different sources : Forbes. Prof. Forbes’s third series of Researches of Heat appears in vol. xiv. of the Edinburgh Transactions, having been read before the Royal Society of Edinburgh, April 16, 1838. It is also REPORT ON RADIANT HEAT. St printed in the London and Edinburgh Journal of Science, vol. xiii. In the first section the author discusses the variable polariza- bility of the different kinds of heat. The establishment of this fact was his object in one portion of his second memoir. But these investigations having been objected to by some, and oppo- site results (as we have seen) obtained by Melloni, the author now repeated the inquiry with every precaution. He rendered ‘the rays parallel by a rock-salt lens, as Melloni had done, and operated at a sufficient distance from the pile: still the differ- ences in the rectangular positions, when different sorts of heat were employed, were as unequal as formerly. - Having varied the experiments in every possible way, he still comes to the same conclusion as before, and gives the following results :— Source of Heat. Rays out of 100 Polarized. PERL LAD, . 5... gieeloe st» “marittn Mie dig PEO 1 eee ean Bey 5% 7 be Wy f Incandescent platina . Se ee Ge tO. 16 —_—_———. with glass screen 80 to 82 Weledhel hamelres tind, oo ¢ sale be ri7S RCE CU ce nw sn es eS Do. with mica screen mG? Al. ph. 6:SO Mercury in crucible at 450° . . . 48 PROMI WERREM A Teh che) lias (fel 44 Melloni’s opposite result of apparent uniform polarizability, the author then shows must necessarily arise from the use of mica piles, consisting of a number of distinct plates super- posed. Such a thickness of mica modifies heat from dark sources in such a way as to give the portion which it trans- mits the same character as to polarizability as luminous heat. Whereas Mr. Forbes’s results were obtained by the use of mica split by heat (as before described), which includes so many sur- faces within a very small thickness, that the polarized heat is comparatively unaltered in its character. He shows directly, that these piles transmit heat from a lamp sifted by glass, and from brass at 700°, in nearly equal proportions, while mica 016 inch thick transmits five times less of the latter than of the former. The second section relates to the dipolarization of heat. Pursuing the methods given in the first series, the author ascer- tained the proportion of heat dipolarized by five different thick- hesses of mica. From the numerical results thus obtained, he deduces the value of the expression in Fresnel’s formula, for 32 REPORT—1840. the retardation divided by the wave-length, either of which quantities being assumed, the other becomes known. In pursuing this calculation, the author finds, that if the numerator (or difference of paths) be assumed to be the same as in light, the length of a wave of heat would result three times as great as that for red light. Upon this he is led into some important considerations bear- ing on the theory of undulations as applicable to heat. Almost exactly similar numerical results were obtained for the heat from an argand lamp, from incandescent platina, and from brass heated to 700°. At the Anniversary Meeting of the Royal Society of London, Nov. 30, 1838, the Rumford Medal was adjudged to Prof. Forbes, “ for his discoveries and investigations of the polarization and double refraction of heat.’’ And in the report of the council announcing the award, a brief but appropriate testimony is given to the value of these researches. Intensity of Reflected Heat: Forbes. On March 18, 1839, Prof. Forbes communicated some re- marks to the Royal Society of Edinburgh on the Intensity of Reflected Light and Heat. The theoretical law for the intensity of reflected light, ori- ginally proposed by Fresnel, has been confirmed on quite differ- ent grounds by the mathematical investigations of Mr. Green and Prof. Kelland. Yet scarcely any attempt has been made toward its verification by direct experiment, except in the cri- tical cases for polarized light originally assumed as the basis of — the formula, and a few intermediate photometrical determina- tions by M. Arago. The uncertainty attending all photometry, led Prof. Forbes to conceive (about the end of 1837) that per- haps some confirmation might be obtained by ascertaining the law which prevails with respect to the intensities of heat in the corresponding cases ; an analogy which seemed extremely pro- bable from the facts already ascertained, relative to the change of polarization, &c., before noticed. In December, 1837, he made some first attempts, which were not altogether satisfactory. In the following winter he resumed the subject, and by a suitable apparatus for measuring the angles of incidence, he endeavoured to measure the intensity of heat reflected from surfaces of glass, steel and silver ; and though the results can hardly be yet considered completely accurate, yet in the case of glass the approximation to Fresnel’s law is closer than any as yet exhibited by photometrical observations : while REPORT ON RADIANT HEAT. 38 the observations accord much better with the law of Fresnel than with that deduced by Mr. Potter. In the instance of me- tals, Prof. Forbes considers Mr. Potter’s discovery verified, that the reflexion is less intense at higher angles of incidence : he has not yet been able to verify Prof. Maccullagh’s ference, that it has a minimum before reaching 90°; and lastly, he observes that the quantity of heat reflected from metals is so much greater than Mr. Potter’s estimate for light, as to lead him to suspect that all that gentleman’s photometric ratios are too small; this would nearly account for their deviations from Fresnel’s law. He has also made some attempts for verifying that law by ob~ servations on heat polarized in opposite planes. Mr. Potter, it is well known, mainly founds his objections to the undulatory theory on the discrepancy between Fresnel’s law for the intensities of reflected light and his own photometrical determinations. He has therefore naturally been led into some controversial remarks on Prof. Forbes’s results in a paper in the London and Edinburgh Journal of Science, to which Prof. Forbes has replied. Considering that the whole inquiry is as yet confessedly in an incomplete state, any further observations upon it in this place would be premature. Conclusion. In thus reviewing the different points of inquiry which have been of late pursued relative to radiant heat, and the several important discoveries with which that research has been re- warded, I have for the most part preserved, under each head, the chronological order. The progress of discovery is here, I trust, too clearly marked to allow any real ground for these questions as to priority and originality, which have given rise to so much unhappy contro- versy between rival philosophers; or to the less open, but equally lamentable manifestations of jealousy, in ambiguous ex- pressions of claims, into which men of science have been some- times betrayed. The dispassionate reviewer of the history of dis- covery at once best avoids all such controversial topics, and ful- fils the demands of critical justice, by a simple but careful statement of facts. In the present instance it appears to me that the share of cre- dit due to the distinguished parties respectively, who have co- operated to introduce the discoveries above reported, is sufli- ciently well-marked, and certainly ample enough in each in- stance to confer the highest celebrity on those who have borne the chief portion of the labour. VOL, 1x. 1840. D 34 REPORT—1840. To the continental philosophers belongs the first invention of the instrument, without whose aid none of these investigations could have been accomplished ; while all the earliest and most im- portant discoveries of the varying diathermancy of substances ; the knowledge of the singular constitution of rock-salt, (which has placed a new instrument in the hands of the experi- menter) ; and the capital fact, disclosed by means of it, the 7e- fraction of heat from dark sources; together with the very sin- gular phenomena of the changes in the nature of heat, by trans- mission through certain substances; the remarkable effect of smoked rock salt; the circularly polarizing power of quartz for heat;—all these important discoveries (besides others of minor value) are imperishably associated with the name of Melloni. Our own country as fairly and incontestably boasts, besides im- provements in the apparatus and methods, many important re- sults connected with the transmission of heat, accurate measures of its refraction, together with some indication of phenomena analogous to those of diffraction. In addition to these, the sole and undisputed credit of first unequivocally establishing the grand facts of the polarization of heat, even from non-luminous sources, by transmission through mica, through tourmaline and by reflexion ; together with the peculiar and invaluable property of mica split by sudden heating (a fact holding a parallel rank with that of the diathermancy of rock salt); the dipolarization of beat; its consequent double refraction and interference ; its circular and elliptic polarization; its length of wave, and the production of that wave by transverse vibrations ; the confirma- tion of the circular polarization by the rock-salt rhomb, and the peculiar effects of metallic reflexion; these constitute the unquestionable claims of Prof. Forbes. On the main point in controversy between these two philoso- phers, the equal or unequal polarizability of heat from different sources, I have endeavoured to place the facts and arguments clearly before the reader; but must confess my own conviction to be in favour of the wneqgual ratio of polarizability in the radi- ations from luminous and from obscure sources, while in some instances the apparently opposite results seem distinctly traced to known causes, and in others the equalization of the effects appears to depend on some of those modifications which the in- tervention of screens produces in the nature of the rays of heat. The very remarkable class of phenomena just referred to, is perhaps of all the recent discoveries that which seems most sin- gular and anomalous : that the same ray should acquire an entire change of property and nature by and in the act of simply pass- ing through certain media, seems little in accordance with any REPORT ON RADIANT HEAT. 35 conception we can form of such radiation. Is this, we may ask, a real change of constitution, or is it a separation or analysis of the ray into its components ? I have elsewhere remarked, that the terms ‘* luminous” and * dark’’ heat are of somewhat barbarous appearance; and the objection is more than etymological, especially 'as' we now find the luminosity of the source is not the essential characteristic of the qualities of the rays. And again, in the compound radia- tion from luminous sources, there is included a considerable por- tion of “dark” heat as disclosed by its relation to surfaces in absorption. The relations of heat to swrfaces in absorption, and in the cor- responding inverse effects of radiation, are among the most im- portant portions of the subject ; and I have in consequence been desirous to draw particular attention to the very valuable inves- tigations of President Bache. The properties which characterize the different species of heat (as we have seen) have been most remarkably developed, and principally studied, in the phenomena of transmission. A wide field is open to the experimenter in connecting these properties with those belonging to the conditions of surface which produce the absorptive powers of bodies for different species of heat ; and these again with those which mark the differences in con- ductive power, and perhaps also capacity for heat. With regard to the establishment of a theory of the nature of radiant heat, we have seen that the hypothesis of undulations certainly supplies a clue to a vast range of phenomena, especially those connected with polarization. The question of the identity of the heating and illuminating radiations seems clearly negatived by many experiments, if we mean it to apply in the sense of one physical agent. But if we refer to the possibility of accounting for the different effects by sets of undulations of the same etherial medium differing in their wave-lengths, this probably presents fewer difficulties than any hypothesis of peculiar heat. We may perhaps suppose some other element besides the wave-length to enter into the explanation: or while we find that the heating effect is due to waves of greater length, it may also be true that the intensity or accumulation of waves, which is necessary for producing the sensation of light, follows a very different and much higher ratio than that requisite for producing heat ; and that this latter effect may be produced in the highest intensity by longer waves of the same etherial medium, but not sufficiently accumulated to impress our visual organs. The difference in the polarizability of heat from different D2 36 REPORT—1840. sources is not explained by the slight difference of refrangibility ; and Prof. Forbes is of opinion that we must in consequence look for its solution to a mechanical theory of heat in some re- spects at least different from that of light. It is even a ques- tion of some difficulty, why any portion of the heat should not be subject to the law of polarization which the rest obeys, unless we suppose the heating effect to be of so complex a nature, that some part of it only is properly due to rays analogous to those of light, while the other part of the effect is produced by a mode of action altogether different. To any such questions, however, we are hardly yet in a condi- tion to give a satisfactory answer; but among the numerous points open to inquiry, I have dwelt more particularly on those which appear to me pre-eminently to require more extended in- vestigation before we can hope to obtain materials for construct- ing any substantial and unexceptionable theory. 37 Supplementary Report on Meteorology. By Jamzs D. Forses, Esq., F.R.S. Sec. R.S. Ep., Professor of Natural Philo- sophy in the University of Edinburgh. [A Summary of the Contents will be found at the end of this Report. ] 1. Tne present Report on Meteorology is intended to be sup- plementary to a former one on the same subject, drawn up by me eight years ago, and printed in the Second Report of the British Association. 2. It was in the contemplation of those persons who assisted in organizing the Association at York in 1831, that the reports on the progress of science should be essentially progressive,— that the same authors, or others, should be engaged to continue from time to time their sketch of the ever-varying point of - view which each science presents, not merely with the intention of registering something like a compendious history of facts, but likewise of philosophizing in some degree upon the new character which, during the elapsed period, science may have assumed,—of indicating the success, or not less instructive failures which may have occurred in attempts to carry forward our knowledge in the lines of direction indicated in previous reports, as the most hopeful or important, and of calling atten- tion to new fields of discovery, new instruments of research, or the collateral suggestions which may often be derived from the progress of the affiliated sciences. 3. My aim in the following report will be—/frst, to sketch the broad features of the science as it stands; secondly, to give the bibliography of the subject within a definite period of years ; and thirdly, to point out the more conspicuous deficiencies of our knowledge, and the kind of observation, experiment or rea- soning by which these blanks may be supplied. In fulfilling this last and responsible duty, the reporter does not lay himself open to the charge which has sometimes been very needlessly preferred, that he is only attempting to stimulate where there is more than energy enough,—that the tide of science is in such full flow, that any external or partial impulse does no more than propagate a local disturbance; that the grand prime- movers,—the wants, ambition, and restless curiosity of men,— would act just as strongly, without assistance or direction, in 38 REPORT—1840. urging the mighty mass steadily forward in its regulated course ; and that at the same height precisely, and at its ap- pointed hour, will its proud waves be stayed. Let us remem- ber that, even admitting the sufficiency of labourers and of enterprize, it is necessary that this power should receive a use- ful direction, that it may not be wasted by misapplication, en- feebled by diffusion, and degraded to unworthy ends. He who points out distinctly where energy may be usefully applied, —who concentrates scattered and disunited forces,—who holds up continually to view the demands of science as worthy of in- dividual pursuit and national encouragement, in opposition to the popular call for the bare quantum of information gleaned from desultory experience, which may penuriously supply the exigency of the moment,—he it is who contributes to the ulti- mate economy of mental labour, to the advancement of sub- stantial knowledge, and, it may be, to raise the intellectual cha- racter of his country. 4. Impressed with these views of the possible utility of re- ports, such as those which the British Association has from time to time required of its members, I attempt the task of continuing my report with more reluctance than I felt in com- mencing it; and, lest more may be expected than I am at all prepared to fulfil, I will premise, that I shall feel myself at liberty to select, for fuller illustrations, those departments of the widely ramified science of meteorology on which I may have some matured suggestions to offer, without in the least degree inferring a depreciation of those topics which the limits, both of time and space, to which I am confined, prevent me from dwelling upon in equal detail. 5. It is not proposed, then, in this report, to supply nearly all the deficiencies which, I am very sensible, exist in the pre- vious one, nor yet to enter at length upon subjects which in it were comparatively untouched, but rather to select such topics as bear most upon general principles, and afford room for prac- tical suggestions; giving, as far as may be, a bibliography of meteorological science in its wider acceptation, particularly during the last eight years. 6. And here I would acknowledge the useful suggestions and information which I have received from the excellent Ger- man edition of my former report, translated and most materi- ally amplified by Mahlmann*, in which many involuntary omis- sions have been ably supplied, and subjects purposely passed * Abriss einer Geschichte der neuern Fortschritte und des gegenwdartigen Zustandes der Meteorologie, &c. iibersetzt und erginzt von W. Mahlmann. Berlin, Liideritz, 1836, pp. 248. SUPPLEMENTARY REPORT ON METEOROLOGY. 39 over with little notice, copiously illustrated. To this work (which is to such a degree original, that I may be allowed to recommend it,) I shall frequently be indebted in the course of these pages. 7. The useful Repertorium (or Analytical Index to Scientific Literature) of Fechner, has been succeeded by the ably-conducted work of Dove and Moser, under the same title, in which it is proposed, somewhat after the manner of the British Association Reports, to analyse the various publications connected with physical science, so as to present, in a cycle of five or six years, a digest of all that has appeared on each subject in the preceding period. The third volume of Dove’s Repertorium*, which has lately appeared, contains a valuable analysis of works on one portion of meteorology. 8. To Professor Kamtz of Halle, beyond all comparison the most devoted meteorologist of the present day, we are indebted for the most laborious systematic compilation which has yet ap- peared upon the subject; ; a compilation, however, which in- cludes many important contributions and generalizations of his own, and which is as much distinguished by copious references to the works of all who have preceded him, as many works of the English and French schools are by the total omission of such literary justice. In the first volume we have the subject of Temperature generally discussed, and that of Wind and of Rain. In the second, is the most complete collection of facts anywhere to be found, on the laws of diurnal and annual changes of temperature, on isothermal lines, and the proper temperature of the globe, followed by a chapter on barometric oscillations, and another on atmospheric electricity. The third volume is chiefly devoted to optical meteorology and terrestrial magnetism. This is the only work we have which can pro- perly be considered as a system of meteorology (with the ex- ception, perhaps, of the article Meteorology in the Encyclopedia Metropolitana, mentioned in the former report). 9. The attempt to systematize and direct meteorological ob- servations within the last eight years, is in nothing better shown than in the various “ Instructions for Observers,’’ which have appeared during that time from various and very influential sources. Some of the special contents of these instruments we shall have occasion to notice, as well as the spirit which they are likely to impress upon future systems of observation, and * Berlin, Veit & Co., 1839, 8vo. + Lehrbuch der Meteorologie, 8vo. 3 Bande, 1831—1836. The saine au- thor has more lately published Experimental Physics, and Lectures on Meteor- ology. 40 REPORT— 1840. on national undertakings ; in the mean time we may enumerate the principal ones by their titles. I. Instructions pour faire des Observations Météorologiques et Magnétiques, par A. T. Kupffer. St. Petersbourg, 1836, 8vo, pp. 77. Chiefly instrumental details ; including, however, a theory of the wet bulb hygrometer. II. Instructions for making and registering Meteorological Observations in Southern Africa. Drawn up under the direc- tion of Sir John Herschel*. III. Instructions pour le Voyage de la Bonité; Physique du Globe, par M. Arago, Comptes Rendus de l’Académie des Sciences de Paris, I. 380. Annuaire du Bureau des Longi- tudes, 1836. IV. Instructions pour |’Expédition d’Algérie, 1838. Par le méme, Comptes Rendus, VII. 206. V. Report of the Committee of Physics and Meteorology of the Royal Society, on the Objects of Scientific Inquiry in those Sciences ; drawn up for the Antarctic Expedition of 1839. Instructions for making Meteorological Observations, pp. 53— 79; with an appendix of Tables. 10. But of all periodical literature, the work which gives the fairest representation of the progress of physical science north of the Alps, is Poggendorff’s dnnalen der Physik, which, even as a bibliographical compendium, is invaluable. In the nu- merous volumes of this admirably edited work, are to be found the best papers published on meteorology, and all the kindred sciences, whether in Germany, France, or Britain. The edi- torial skill and impartiality with which this work is conducted, render it most deserving of support in every country; whilst the high scientific standard, according to which articles are ad- mitted or selected, is highly creditable to Germany ; where alone, perhaps, in Europe, so learned a work would find ade- quate support}. 11. I regret very much that, from the difficulty of procuring * These instructions, printed by the South African Institution, have, I be- lieve, been republished in the Journal of the Royal Geographical Society. See also Instructions for Observation, and Suggestions for Meteorological Inquiry, in the first volume of the Transactions of the Meteorological Society of Lon- don, 8vo. + M. Poggendorff, not satisfied with translating the best foreign memoirs of the day (to facilitate which he has recently added an annual supplementary part), has, on various occasions, published, for the first time in German, older memoirs, of considerable length and difficulty, for the purpose of presenting his readers with a complete view of the progress of any science, without searching further than his own pages. Thus, he has lately translated Fresnel’s Memoir on Diffraction, and Sir James Hall’s papers on the Consolidation of Strata. SUPPLEMENTARY REPORT ON METEOROLOGY. 41 with the least regularity the periodical literature of Italy, I am unable to present any connected view of what has lately been effected in that country for meteorological science. The obser- vations of Sig. Cacciatore, of Palermo, on a uniform system of standards for meteorological observations*, are among the few that have come to my knowledge. Let us hope that the re- cently founded Association of Italian Philosophers will do something towards supplying the want of information under which we labour of the actual progress of science in that countryt. 12. Since the last Report on Meteorology, Mr. Luke Howard has published a second greatly enlarged edition of his Climate of London{, which deserves to be considered, not as a mere journal of observations, but in some degree as a systematic work. Professor Stevelly, of Belfast, promises an elementary treatise, the first in our language. M. Quetelet, of Brussels, has published a full account of the history of Meteorology in the Pays Bas§, to which, however, his own contributions are by far the most important. 13. This might appear the natural place for enumerating the public establishments lately founded for cultivating (amongst »ther things) the practical part of meteorology. When, however, we shall have considered a little minutely the condition of the science in its several branches, we shall be bet- ter able to appreciate their value, and suggest measures for their extension. (See Suggestions at the close of this Report.) 14. I proceed now to the different departments of meteor- ology, nearly in the order in which they were discussed in my former report||. I have already stated (4.) why I shall hold myself at liberty to enlarge more upon some topics than others, or even restrict myself occasionally to a mere enumeration of * De redigendis Observationibus Meteorologicis. Panormi, 1832. + In the Bibliotheque Universelle de Généve, is generally to be found a fuller notice of Italian papers than in other journals published north of the Alps. This practice might, with advantage, be yet further extended. Since this was written, I made it my particular business, during a visit to London, to search for Italian Scientific Journals. In none of the public libra- ries where I made application, as most likely to obtain such works, could I find that Italian Journals are regularly subscribed for or received! A new Tuscan Scientific Journal is recently announced, with the names of Amici and Savi amongst the editors. f 3 vols. 8vo, Lond. 1838. § Apercu Historique des Observations de Météorologie, faites en Belgique jusqu’a ce jour, 4to, Bruxelles, 1834. || I take this opportunity of returning my thanks generally for the commu- nication of valuable meteorological papers, in a detached form, from the respect- ive authors, which, for the most part, will be found cited in the following pages. 42 REPORT—1840. memoirs, which may assist the researches of others, and en- able them to draw their own conclusions. I.—TEMPERATURE. 15. Meteorology may, in some sense, be considered as a mere branch of the science of heat in its widest application. Were our globe and atmosphere in a uniform state with re- gard to heat, and not subjected, by astronomical and cosmical laws, to perpetual and material changes in the distribution of temperature in its solid, fluid, and gaseous parts, the simplest considerations would suffice for the solution of the few pro- blems which could then be called meteorological. 16. It is to the different inclination of the solar rays, that we trace the effect of climate varying with latitude, and of cli- mate varying with season. It is to the unequal absorption and radiation of heat by seas and continents, that we ascribe the curious inflections of the isothermal lines, and the characters of moderate and excessive climates. It is to the combination of these causes with the rotation of the globe, that we attribute all the phenomena of wind, from the steady monotony of the Trades, to the capricious changes of higher latitudes, the Tor- nados of America, and the Typhoon of the Chinese seas. It is to the mechanical transport of great masses of air due to change of temperature and consequent expansion, that we look for the explanation of most of the irregular, and several of the periodical barometric fluctuations. Lastly, it is to the varying conditions of temperature proper to the day and night, to one sea- son and another, in high latitudes and low, that we look for prin- ciples to guide us in the difficult, but important determination of the hygrometric elements of our atmosphere, the ceaseless mo- difications of that fluctuating ocean of vapour which floats in- dependent of, and unobstructed by, the permanently elastic envelope of our globe, which (though comparatively unheeded by us) is subject to all the variations of pressure and tempera- ture of the common atmosphere, but through limits far wider, and to changes of physical condition, which the other, from its permanent character, never presents. 17. If we choose, then, to consider the grand meteorological problem for a moment synthetically, instead of analytically— T mean, by regarding the known causes which influence cli- mate, and applying to these the laws of distribution and com- munication of heat, which are deduced from laboratory experi- ments, and from the first data or experimental axioms of that science,—we have, at least, the advantage of perceiving the magnitude, interest, and definitiveness of the problems with SUPPLEMENTARY REPORT ON METEOROLOGY. 43 which meteorology, in the philosophical sense of the term, is conversant. Those who limit themselves to a few daily mecha- nical observations of the barometer and thermometer, or who even apply the results of these simple, but (if wel! conducted) important observations, are little aware that the science they cultivate is capable of giving definite answers to questions which might seem further removed from human apprehension than even the problems of physical astronomy, such as the con- dition of the interior of our globe with respect to temperature,— and in some degree its history as regards periods of geological convulsion,—the whole measure of solar heat received by our globe in a given time,—the condition of the highest, and for ever inaccessible parts of our atmosphere,—the temperature which reigns in the vast regions of space, remote from the influence of any planet or satellite, however small, whose presence and pro- per heat would yet influence such an experiment ;—these are amongst the great cosmical problems which we do not mean to say have been solved, but which there is little reason to doubt that we are in the fair way of one day being able to solve by instruments such as we now possess, with the aid of theoretical investigations identical in kind with many which have been completely mastered. 18. Of Instruments, those which are most called for are such as acquaint us with certain physical constants, or approximate constants, which determine for our globe and its atmosphere the particular application of the general laws of the Conduc- tion and Radiation of Heat. Of theoretical Investigations, WG require such as shall solve with sufficient generality the problems with which we have to deal, but stripped of those exuberant claims to mathematical precision which cramp their application and discourage those who know how far we are from even the chance of ever attaining to a degree of accu- racy which such niceties pre-suppose. The theoretical in- vestigations of most use, then, are those which, taking the pro- blem in a general way, show exactly upon what arbitrary con- stants the determination (for instance) of the climateric condition of any point of the globe at any moment depends. This is a task of no smal] difficulty, even in the simplest form in which it can be put. 19. It infers a knowledge (1) of the fundamental laws or axioms of the science of heat (such as the law of expansion, variation of specific heat with density, conduction, radiation). (2) Of all the physical circumstances which can possibly influence the temperature of our globe, that is, the communication of heat to, or abstraction from it (1 mean their existence, not their de- 44 REPORT— 1840. termination), such as solar radiation, the proper heat of the earth, the proper heat of the atmosphere, the proper heat of space. (3) Supposing these preliminaries rightly assigned, next comes the arduous mathematical investigation of the way in which the unknown constants which represent these various energetic sources of modification, enter into the final expression of atmo- spheric temperature, or whatever be the particular problem under consideration. (4) For the determination of the constants (which are supposed to be reduced to the least number of inde- pendent elements), the analyst is further bound to mould his formule into such a shape as to insulate a certain number of the constants in such a way that they may be determined by direct physical experiment ; whence the others not so determinable may be inferred by the principle of exclusion, which assigns the difference between the sum of effects due to causes already esti- mated, and the observed effect, to a remaining cause (such as the temperature of space) which does not admit of such direct estimation. 20. The duty of the experimentalist is thus clearly defined. Perhaps the most important observations which man can make for furthering the theory of the universe, are such as no general sagacity, no patient attention to mere facts as they are presented in the course of nature, could possibly have indicated. And it is the most satisfactory and encouraging proof that such a syn- thetic mode of treating the problem is not an injurious or an illusory one, when we find many concurrent observations set on foot in the way which theory has indicated, leading under vary- ing circumstances to a common result. Such instances are not uncommon, and will fall to be noticed hereafter*. 21. It is plain, then, that there are three departments of sci- ence which must go hand in hand to perfect a mixed science like that of meteorology. First, the experimental philoso- pher must advise generally on the experimental axioms, and on the modifications which they are to receive in order to allow for causes which yet do not admit of nice numerical estimation ; he must further be fully persuaded that »o energetic cause of modification has been left out of account; for in so delicate an inquiry, where the principle of exclusion is to be acted upon, enormous errors would result from any oversight in this stage * Such, for instance, as the geometrical diminution of the range of animal temperature beneath the surface of the ground, as we descend in arithmetical progression : the wniform retardation of epoch in the same circumstances, and perhaps we might have added a few years ago, the agreement of several different methods of approximation to the actual temperature of space. See former Re- port, p. 203, and Mahlmann’s Translation, p. 14. SUPPLEMENTARY REPORT ON METEOROLOGY. 45 of the process. Secondly, the mathematician requires the ut- most resources of his analysis to obtain in a definite and tangi- ble form the resultant action (we will suppose that tempera- ture is the question) of all the heating and cooling influences upon acertain point, whose coordinates are given (including elevation in the atmosphere, or depression below the surface), and at a particular instant of time. And in this investigation he will, as we have said, chiefly show his skill in the precision which he gives to his results, the judgement with which he intro- duces needful approximations at that stage of the investigation which shall tend most to simplicity, and in the exhibition of his results in forms adapted to experimental verification. Then follows the duty, in the third place, of the observer, or practical meteorolegist, which is to follow the indications which theory assigns for the determination of data, and for which the me- thods will be indicated by a competent knowledge of experi- mental philosophy, and even by prolonged tentative researches in the laboratery. It is not unoften the provoking result of the labour expended by the two first sections of investigators, that the whole problem is found to turn upon certain quantities, whose nature is perfectly well understood, but which are, and threaten for ever to remain perfectly unknown. I need hardly stop to point out that such a threefold division of labour is to be found in many other sciences, and notably at present in that of magnetism. A right appreciation of the steps leading to the solution of such complex mixed problems, which in fact involve a whole science, is the first step to their solution; and we commonly find that this is performed by the appearance of some master mind, capable of seizing the question in all its ex- tent and under every one of these forms—depending on a ver- satility of mental endowment of no common order. This is what Newton did for the science of gravitation, what is now being done by the union of many for the science of optics, and what Gauss has pre-eminently done for the science of mag- netism. 22. It will conduce to clearness if it is understood, that so far as possible, in what follows, we shall keep in view these different aspects of meteorological science ; and combining, as on a for- mer occasion, the bibliography with the general detail, I shall proceed to the different parts of the science of Temperature somewhat in the order adopted in the last report. 46 REPORT— 1840. A. Thermometers* . 23. Fired Points.—Legrand+ has studied once more the vexed subject of the rise of the thermometric zero point. He finds that the pressure of air has no influence, thus confirming the observations of Bellani; the molecular change in the form of the bulb is therefore the remaining cause, and this is confirmed by finding that it depends on the nature of the glass; not oc- curring (according to the author) in Crystal. Now if by Crystal is meant, as I believe to be the case, Flint Glass, this obser- vation is at variance with that of other observers, flint glass being generally used for thermometers in this country. Since writing the last report, I have myself found the following dis- placement of zero in thermometers all warranted standards by the following makers—Troughton and Simms(two), Adie, Crich- ton, Collardeau :— + 0°°56, + 0°°33, + 0°41, + 0°54, + 0°35, Fahrenheit. 24. Correction of Scale. When the points are fixed and the thermometer graduated, the degrees may be examined by the method of Bessel{. Rudberg has proposed another founded on similar principles§, and I have given an account of a method employed by myself, and attended, I think, with considerable practical advantages, in the introduction to a paper on the Tem- perature of Hot Springs]. 25. Every one must have noticed the difficulty of reading ther- mometers quickly and correctly when the tube projects much in front of the scale, owing to an evident error of parallax, which it requires some experience to avoid. A particularly ingenious method of correcting it has been communicated to me by M. Valz, the eminent astronomer of Marseilles, which though un- published, I trust he will forgive me for mentioning. By plun- ging two-thirds of the diameter of the tube into the material of the scale so that the plane on which graduation is made is ad- vanced in front of the mercurial column to the amount of one- third of the radius of the tube, it may be shown that the error of refraction will exactly correct the error of parallax. 26. For self-registering thermometers for maximum tempe- ratures, such as are now in demand for experiments on deep Arte- sian Wells, we have the overflowing principle of Cavendish and * See last Report, p. 208. Mahlmann, p. 25. t Comptes Rendus (Paris), iv. 173. t Berzelius, Jahresbericht, xv. 70, quoted in Poggendorff's Annalen, xxxvii. 376. § See a full illustration of Bessel’s method in Kupffer’s * Instructions,” p. 5. || Philosophical Transactions, 1836, p. 571. SUPPLEMENTARY REPORT ON METEOROLOGY. 47 Magnus* revived by Walferdin, and his instruments are usually employed in Parist. The overflowing principle has been used (in the same way as in Wollaston’s thermo-metrical barometer) for constructing a thermometer sensible to small change of ani- mal heat by Dr. Marshall Hallt. Jurgenson, the chronometer- maker of Copenhagen, has proposed a clock for estimating the mean temperature of limited periods, in which the compensation shall be inverted, and the natural effect of temperature on the rate of an uncompensated clock exaggerated§. 27. Several other methods or new applications of known principles have been proposed for the measure of temperature besides that of expansion commonly employed. The extensive introduction of the thermo-electric pile of Nobiliand Melloni, in delicate researches on radiant heat, has suggested the use of the same principle in other cases. Indeed it seems peculiarly adapted for ascertaining the condition of inaccessible points in respect of temperature. M. Peltier, of Paris, I believe, first pro- posed the application of long wires of heterogeneous metals to ascertain at a distance the temperature of their point of junction, however distant. The method is briefly this: suppose two wires of copper and iron respectively, and of equal lengths, laid side by side and soldered at each end. Let one of the wires be cut, and a galvanometer introduced into the open circuit thus made. It is well known that the galvanometer needle will not stand at zero under these circumstances, unless both solderings have a common temperature. As the temperature of one ex- ceeds or falls below that of the other, the index will move in one or other direction, and in a well-constructed instrument the de- viations will be almost exactly as the variations of temperature ||. Thus, one junction of the wires being plunged in water of known temperature, and the positive or negative deviation of the galva- nometer being known and converted into thermometric degrees, the temperature of the other soldering (which may be inaccess- ible and removed to a considerable distance) becomes known. This very ingenious arrangement was shown to me in June, 1835, by M. Peltier, whose acquaintance I owe to the attention of M. Elie de Beaumont. 28. The application of the thermo-electro-magnetic princi- ple becomes easy in very many cases. It has been proposed for pyrometers by M. Pouillet, who has compared the march of such * First Report, p. 209. + Comptes Rendus (Paris), ii. 505, 619. { British Association Reports. § Comptes Rendus, iii. 142. Compare First Report, p. 213. || I am aware that this position has been controverted. I am satisfied, how- ever, of its general truth from careful experiments. 48 REPORT—1840. an instrument at high temperatures with that of an air pyrome- ter*, and at very low temperatures obtained by means of M. Thilorier’s happy discovery of the solidification of carbonic acid with air and alcoholt. 29. MM. Becquerel and Breschet have employed the same method for the determination of the temperature of water at great depths by sinking the experimental junction of the wires. As may be supposed, however, in such cases, great attention is requisite to prevent the slightest chemical action, which would develope its proper current. They made their observations on the Lake of Genevaf. 30. The same ingenious experimenters have applied this me- thod of measuring temperature to the living animal fibre, by thrusting a compound needle into the muscular tissue, and with very curious results§. M. Dutrochet has lately applied the same method to ascertain the proper temperature of plants, a yet far more difficult inquiry||. His experiments haye been fully corroborated by MM. Van Beek and Bergsma]. 31. I have applied M. Peltier’s apparatus for the very obvious purpose of checking the zero point of thermometers sunk in the ground to such a depth that their scale can never be re-examined. For this purpose, along with a thermometer 24 French feet long**, I sunk a thermo-electric pair of iron and copper, com- pletely defended in all its length with a casing impervious to water, and its indications have been generally satisfactory. I had hoped that, by the use of wires of sufficient thickness, the thermo-electric current might be communicated from great depths. From experiments which I have made, I am inclined to think that their use must be very much limited in this respect, on account of the rapidity with which the energy of the circuit * Comptes Rendus (Paris), iii. 782. + Ibid, i. 513. Professor Muncke, of Heidelberg, has investigated with great care the law of dilatation of alcohol, and the result gives for ordinary atmospheric temperatures, a value very sensibly different from the mean dilata- tion commonly received from Dalton’s experiments. He has also given the result of several series of observations on other fluids, and given formule of ex- pansion for each.—Petersburg Transactions—Paper read 5th Sept. 1834. M. Rudberg has re-examined the expansibility of dry air and gases (Poggendorfi’s Annalen), and he finds an expansion of only 364 or 365 between freezing and boiling water instead of °375, as was given very nearly both hy Dalton and Gay Lussac. ‘The scientific world will, no doubt, hesitate a little to adopt the new determination of this important element, even with all possible respect for M. Rudberg’s known skill as an experimentalist. + Bibliotheque Universelle, Nouvelle Série, vii. 173 (1837). § Comptes Rendus (Paris), i. 28, iii. 771. || Ibid, viii. 695, 741, 907. ix. 613. Temp. of Insects, ix. 8]. q Ibid, ix. 328. * #** See below. Art. (96.) SUPPLEMENTARY REPORT ON METEOROLOGY. 49 diminishes with the Jength of the conducting wire. Some ad- vantage is undoubtedly gained by using two or three pairs, acting simultaneously, instead of one. Wherever distant com- parisons are intended, it is of great consequence to have a standard thermo-electric combination, by which any change in the sensibility of the galvanometer may be tested. 32. A method of determining the temperature and pressure of the atmosphere depending on very different principles, has lately been proposed by M. Arago*. It depends on the known optical principle, that if a pencil of light radiating from a small and distant source be divided into two parts, and one of these be in the least degree retarded more than the other, coloured fringes will appear when the two pencils are re-united and suf- fered to fall upon a screen or received on an eye-piece. If by any arrangement, whether of reflexion or refraction, these bands have been already formed, their breadth and aspect will be changed by such a retardation of either component pencil. Now air rarefied, whether by heat, diminished pressure, or the intermixture of vapour, acts less energetically in retarding light ; consequently a tube with glass ends, filled with such modified air made to transmit one pencil, whilst the other passes through a precisely similar tube of standard air, will exhibit by the pro- duction of movement of the fringes very minute changes in its physical condition. It remains to be shown, however, by what mechanical adaptations M. Arago proposes to make this delicate experiment susceptible of general application. This he pro- poses to point out in a future memoirf. 33. The comparison of ordinary thermometers with standards is often a matter of great importance, and too little attended to. The increasing demands of science require a proportionable in- crease in the consistency of instrumental indications; not so much indeed for ascertaining the temperature, as in many other experiments connected with the temperature of the ground, rivers and hot springs. Travellers should seize every oppor- tunity to verify the freezing points of their instruments, and this is an easy matter ; but to compare thermometers at temperatures above 100° F., is a practical problem of far greater difficulty than is commonly imagined. Plunging them together in laboratory vessels of hot water is a most unsatisfactory process, even if the sensibilities of the instruments be pretty equal. If they are very unlike, it is all but impossible, although the correction for the gradual cooling of the medium becomes then a pretty mathe- matical problem{. Where the investigation is an important one, * Comptes Rendus (1840). + Ibid. t Fourier, Théorie de la Chaleur, p.357, and Kelland’s Theory of Heat, p. 84, 1840, E 50 REPORT—1840. or many instruments are to be compared, constant sources of heat, natural or artificial, cannot be too carefully sought. Bark pits, natural hot springs, even the waste hot-water of steam- engines, and the boiling point of some liquids, such as alcohol, may be usefully employed*. B. Atmospheric Temperaturet. 34. Under this head we consider the temperature of a given spot at different times. These variations are diurnal, annual, and those of long period. 35. A summary of valuable facts on this subject may be found in Kamtz’s Meteorologiet and Dove’s Repertorium§. We can only point out a few general facts of especial importance. 36. The general practice in Germany of expressing periodic changes of temperature by series of the form T=A + Bsin(#+ C) + Dsin (2a + KH) + &c., where x is the hour angle, or the fraction of a year, is attended with considerable advantages, especially for the purposes of in- terpolation ; and if this has sometimes been carried perhaps too far, yet the reductions are on the whole very superior to those in use in this country, 37. The value of hourly observations of temperature seems now to be fully admitted, and the two-hourly meteorological observations connected with the recent magnetic expeditions fitted out by the English government, are likely to be of the highest importance for science. In the mean time we may quote the following important contributions, in addition to those spe- cified in the former report. 1. Goldingham’s hourly observa~- tions, three times a month at Madras ||. 2. Brandes’s observa- tions at Salzuflen (lat. 52° 3! N.), made every hour in the year 182894. 3. The observations which, at the earnest suggestion of the Meteorological Committee of the British Association at its first meeting at York, have been so ably and zealously car- ried on hourly for seven complete years, under the direction of Mr. Snow Harris at Plymouth. The means have been regularly - * T have found by the most careful experiments that the temperature of the vapour of impure alcohol remains surprisingly steady, which was before re- marked by Hugi (Alpenreise, Solothurn, 1830), but it is not the same with zther. There are some interesting experiments on the constancy of the tem- perature of vapour from saline solutions in the late volumes of Poggendorff’s Annalen, especially by Rudberg, xxxiv. 527. + See former Report, p. 210. Mahlmann, p. 31. t Vol. iii. p. 342. -§ Vol. ii. p. 1. || Madras Observatory Papers, calculated by Dove. §| Archiv der Pharmacie, Reihe ii. Bd. xi. 1, quoted in Poggendorff, xli. 635, and Poggendorff’s Remarks, xli. 630. Compare Comptes Rendus (Paris), i. 264, and Dove’s Repertorium, iii, 345. ed SUPPLEMENTARY REPORT ON METEOROLOGY. 51 calculated and communicated to the Association in two reports on the subject*. 4. A most interesting series of observations made every two hours in the inhospitable regions of Nova Zem- bla, has been published by M. von Baer of St. Petersburgh, to whom I am indebted for a copy of his paperst. Some of his results we will immediately mention. 5. Dr. Richardson has undertaken the most laborious but most useful task of reducing into order, and into their mean results, the extensive series of two-hourly observations made in various years in the arctic regions of America by the expeditions of Parry and Franklin t. This has also been partially done by M. von Baer, in the me- moirs last-cited, so that we have in some measure a more com- plete meteorological knowledge of the climate of these desolate regions than we can be said to possess of that of our own coun- try. Dr. Richardson has carefully compared his diurnal curves with those of Leith and Plymouth, and we find the constancy of the interval between the hours of mean temperature§ here remarkably reproduced, and also in a remarkable manner, Brew- ster’s law of the correspondence of the mean temperature of two hours of the same name for the whole year with the mean tem- perature of the year||._ The latter fact comes out exceedingly well also from the tropical observations of M. Freycinet], and from the table of Brandes already referred to**. 38. All these observations go a long way towards the il- lustration of those general laws of climate which may be con- sidered in some measure independent of local causes. It is not easy perhaps to conceive a more violent contrast of climate than the continental one of arctic America, and the insular one of Plymouth. It were undoubtedly to be desired, however, that these observations were extended to tropical regions; and the expeditions recently fitted out to St. Helena, the Cape of Good * British Association, Fifth Report, p. 181; Eighth Report, p. 26. + Ueber das Clima von Nowaja-Semlja und die Mittlere Temperatur insbe- sondere ; Ueber den Jahrlichen Gang der Temperatur in Nowaja-Semlja. Von K. E. v. Baer.—Bulletin de ? Acad. Imp. de St. Pétersbourg, t. ii. No. 19. t Journal of the Royal Geographical Society, 1839. § See First Report, p. 211. || Richardson, p. 39. From a communication made by Mr. Harris at Bir- mingham in 1839, it appears that hourly observations have been made at Phi- ladelphia (United States) and in Ceylon ; but the results are not published. {| Poisson, Théorie de la Chaleur, p. 465. ** To these may now be added two sets of hourly observations in Inverness- shire, made at the expense of the British Association under the direction of Sir D, Brewster. From the communication made by that gentleman to the Meeting of the Association in 1840, since this report was written, it appears, that in these observations also, the constancy of the interval between the hours of mean temperature mentioned in the text, is well preserved. EQ? 52 REPORT—[840. Hope, and the possessions of the East India Company, will doubtless ere long afford this information*. 39. The interesting tables of Von Baer and Richardson illus- trate most remarkably the different progress of solar heat in arctic and temperate latitudes. The maximum daily range which occurs in the end of July at Padua, and exceeds 9° cent., occurs in March in Boothia (North America), and at Felsen Bay (Nova Zembla), in Aprilf, the values being about 7° cent. At Leith the range is nearly uniform from April to July, and does not reach 6° cent., a proof of a temperate or insular climate. When the sun is always below the horizon, the diurnal curve is, as may be supposed, very uncertain, and wavering. In winter in Nova Zembla there is a sensible increase of temperature towards midnight, at both stations}; and something of the same kind is visible in several of Dr. Richardson’s winter curves. 40. The dependence of the form of the annual curve upon the insular or continental character of a locality, does not need here to be insisted on. But it is interesting to observe the contrast between the climates of arctic Asia and arctic Ame- rica, both so rigorous, yet so unlike :— The mean temp. of Nova Zembla is 16°F. Of Fort Franklin 17-6 Mean temp. three summer months 36°5 # 50-4 + three winter months —3 is —17°8 Nova Zembla, therefore, is a climate of wretched mediocrity ; one of the most dreary in the known world; the summer tem- perature scarcely rises above the freezing point! whilst arctic America enjoys a European warmth for at least some weeks. The warmest month at Nova Zembla (August) has a temperature (39° F.) less than that of January in Shetland. The warmest month at Fort Franklin reaches 52°, or almost that of July in Shetland. The extremes are not less surprisingly different :— Extreme heat at Nova Zembla 49° F. At Fort Franklin 80° F. $5 cold “ —53§ " —58§ Range 102 138 * Since this report was written, I had the satisfaction of seeing, at the Tenth Meeting of the British Association, the admirable observations of Mr. Calde- cott, at Trevandrum, in lat. 8° 30’ N., which it may be hoped will soon be published. They are on the thermometer, barometer, and hygrometer, made hourly for three years. + The reason, of course, being, that as the sun approaches perpetual appa- rition, the daily variation diminishes. There is an approximation to this at Leith. + Von Baer, Taglicher Gang., p. 9. § The extreme of —53 appears to be a very uncommon one at Nova Zembla, much more so than —58 in North America. Captain Back observed so great a cold as —70°. SUPPLEMENTARY REPORT ON METEOROLOGY. 53 Enormous as both these ranges are, we cannot but observe that the Asiatic extreme warmth does not approach within 30° of the American one! and yet the mean temperature of both sta- tions is nearly alike. 41. The determination of the diurnal curve of temperature and its variations may be almost called complete, in comparison with that of the annual curve, which, notwithstanding, is a matter in some respects of still more important concern. Even the mean temperature of a place, at any period, is very difficult to fix, owing to the great discrepancies of successive seasons. Thus 29 years, from 1806 to 1834, during which comparable observations have been statedly made at the Observatory at Paris, give a mean of 10822 cent., with a variation between one year and another from 12%10c. in 1822, to 9°35c. in 1829, the difference being almost 5° of Fahrenheit*. It is evident that many years must be required to fix even this comparatively simple datum; how much more to determine the form of the annual curve which, in every region, is doubtless characterized by peculiar inflections ! 42. The study of the annual curve is very much retarded by the want of simple, permanent, and comparable meteorological observations. These, which require little expense and little time, pre-suppose, from the extent of years over which they must extend, a kind of co-operation to which too little attention has been directed. The Paris observations are perhaps the only ones to which we can look with any degree of confidence in this respect, even for the comparatively short period of thirty years. Professor Brandes, of Breslau, has, with praiseworthy industry, collected and reduced a vast number of observations, continued at various stations for eight, ten, or more years, and has compared them and projected the annual curves, which he obtains by finding the mean temperature of successive periods of fivedayst. The chief stations are Petersburg, Stockholm, Cux- haven, Zwanenburg, London, Mannheim, Vienna, St. Gotthard, La Rochelle, and Rome. In these curves, imperfect as they are, are well shown the peculiarities of insular and continental climates, and those of plains and mountains. Some points of agreement may probably be found in all, for which sufficient reasons may be assigned; such as the more rapid increase of temperature than its decline, which applies equally to the diur- nal curve. This is, I conceive, chiefly owing to two causes, * Poisson, Théorie de la Chaleur, p. 463. + Beitrage zur Witterungskunde, von H. W. Brandes. 8vo. 1820. Unter- metuungen uber den mittleren Gang der Warme-Aenderungen durchs ganze ahr. 54 REPORT—1840. which I will simply indicate: first, that by its nature the absorption of heat due to direct radiation from the sun must go on more rapidly than the dissipation of it by cooling; and secondly, that some influence may be attributed to the different distribution of vapour during the rise and decline of tempera- ture. 43. Owing to these causes, thermometric curves, if they can be assimilated to symmetric geometrical curves at all, such as parabolas, must be regarded as having their axes oblique and not vertical. An erect parabola cannot even, generally speak- ing, be employed for finding the maximum with exactness on this account. But, in point of fact, no one parabola can repre- sent all the parts of the thermometric curves which, in their least complicated forms, approach more nearly to the curve of sines. 44, From the tables of Brandes and others, we may infer the probability of discovering special inflections of the annual curve which characterize particular regions of the globe. The European curves point, for instance, with great distinctness to a check in the progressive rise of temperature, owing to the increasing power of the sun, which occurs almost invariably in the middle of February. This inflection of the annual curve, which in Europe always bends it towards horizontality, and sometimes produces distinctly a second minimum in March, is a circumstance which has attracted too little attention, and as an indication of other general inflections deserves notice. This circumstance has lately been insisted on by M. Erman, in a letter to M. Arago*, who ascribes it, I think, with unwarrant- able boldness, to the interception of the solar rays by the pas- sage of the meteors of November between the earth and sun! I believe that it can be very easily accounted for, as occurring in Europe (which is all we know at present), by the periodic easterly winds of spring, caused by an unequal effect of tem- perature which we shall presently notice, and which almost invariably set in for a time at that season, bringing masses of cold air, from the continental regions of Europe and Asia, to the western shores +. * Comptes Rendus (Paris), x. 21. (1840.) ¢ Since these pages were written, I have received from Prof. Dove of Ber- lin his elaborate Memoir “ on the non-periodic changes of the Distribution of Temperature on the Earth’s Surface,” in which he has collected the most com- plete series existing of authentic observations of monthly mean temperature for fifty-nine stations. One of his conclusions is remarkable, viz. that when a large portion of the earth’s surface is taken into view, the apparent irregularities of particular seasons counteract one another, so as to give no countenance to the idea, that more heat falls on the earth generally one year than another. SUPPLEMENTARY REPORT ON METEOROLOGY. 55 C. Isothermal Lines*. 45, We will despatch very quickly what is to be said on the very important subject of climatology, because no material step whatever has been made since the publication of the last report. A considerable number of detached observations, of various degrees of merit, on the mean annual and monthly temperatures of many points of the earth’s surface, have no doubt been added, and a list of many of these monographs may be found in Dove’s Repertorium+, and in the Transactions of the Meteorological Society. M. Kamtz has performed the use- ful labour of amassing all the trustworthy observations of mean temperature which he could discover, and presenting the monthly means, in the second volume of his Meteorology. The German translation by Mahlmann of my former report, embraces figures on different projections of the isothermal and isogeothermal lines. Both of these, especially the last, require still the greatest attention, even to give an approximation to truth; but we have not yet obtained the roughest sketch of the variations which these lines undergo with change of season; in other words, of the isocheimal and isotheral lines { ; yet these are of the greatest practical importance. The distribution of animal and vegetable life materially depends on them; the boundary of some plants being determined by the minimum winter temperature, and the advantageous cultivation of most by the extreme heat of sum- mer; the limits of the vine, maize, and olive depend on these circumstances ; and the region of barley so exactly coincides with the isotheral line, that (according to Wahlenberg) barley ripens wherever the mean temperature of ninety consecutive days rises to 48° Fahr. 46. Professor Dove has not inaptly compared the annual variations of the form of the great system of isothermal lines to those which the Lemniscates formed in some biaxal crystals seen by polarized light undergo by changes of temperature§. 47. These variations (to which we would particularly direct the efforts of meteorologists) are the more important, because, as we have already seen in treating of the form of the annual curve, places may have the same mean temperature, and yet their climates may have no real resemblance whatsoever (as when we compare the climates of Nova Zembla and Fort Franklin in North America, and those of Unst in Shetland and Copenhagen); and these characters may depend in a good measure upon local circumstances. Those who argue about * Last Report, p. 214, &c. Mahlmann, p. 45. } iil. 266. t Last Report, p. 218. § L’Institut, No. 325. 56 REPORT—1840. the constancy or inconstancy of climates from ancient times to the present*, would do well to recollect that their criteria are almost all drawn either from extreme temperatures, or from the facts of botanical geography, neither of which give true indi- cations of the mean annual temperature of a climate. 48. From various remote regions we continue to receive in- teresting reports of the mean temperature, which seem gene- rally to be more carefully and consistently made than in stations of easier access. It is indeed surprising, in how few points of the civilized parts of Europe the mean temperature can be said to be known with any degree of exactness, to which the verifi- cation of thermometers is an indispensable preliminary. We may mention, as particularly interesting amongst observations in the most inhospitable regions of the globe, the observations at Nova Zemblat, Dr. Richardson's reduction of those of Parry and Franklin, the observations of Beechey, Ross, and Back, in their respective voyages, the last of whom observed the greatest natural cold yet registered}; Kupffer and Brewster§ on the temperatures observed on the north-west coast of America, and Arago upon similar observations by Macloughlin ||. Mr. Web- ster has given a list of extreme winters observed in North America ¥ ; and Dr. Daubeny some observations on the climate of that country** ; Mr. Trevelyan has reprinted his paper on the Climate and Vegetation of Farve, with additions+7. 49. We have already observed, that it appears, by a reference to the Paris Tables, that a long series of years of observation is required to obtain with certainty the mean temperature of a place t{. It is probable that the temperature of the ground is not liable to so great fluctuation, and therefore that kind of obser- vation should be made wherever practicable. This does not, how- ever, supersede the necessity of long-continued meteorological observations with verified instruments made under proper pre- cautions ; and we hope to see the Plymouth observations, and those conducted at the various magnetic stations fixed upon by * See on this interesting subject Arago, Annuaire, 1834; Schouw on the Climate of Italy (Ed. Phil. Journal, July 1840), and an anonymous paper in the Phil. Mag., Aug. 1840. t+ Supra Art., 37—40. t Ibid. § Phil. Mag., 3rd Series, i. 427. || Comptes Rendus (Paris), i. 266. q Silliman’s Journal, xxviii. 183. The valuable Meteorological Reports from the State of New York are still continued, and, through the kindness of Dr. Romeyn Beck, I have received them down to 1837. ** Brit. Assoc., Eighth Rep., Sect. p. 29. tt 4to. Florence, 1837. +¢ The longest extant series of meteorological observations worthy of any confidence is probably that at Berlin, printed in Dove’s paper on Non-periodic Variations of Temperature (Berlin, 1840). It extends from 1719 to 1839; the greatest annual temperature was 9°69 R. in 1756: the least 4°°38 R. in 1740. SUPPLEMENTARY REPORT ON METEOROLOGY. be the British government, continued for a series of years on this account. M. Boussingault has remarked, that at the Equator the mean temperature of any place may be found at any time of the year, and at any hour of the day, by digging a pit in a shady spot a foot deep, and observing the temperature at the bottom of it*. M. Poisson considers this result as conform- able to theory}. It is, at all events, a most convenient fact, and adds one to the many encouragements which nature affords to the prosecution of meteorology in tropical regions, where hitherto it has been most neglected. 50. The improvement of our knowledge of terrestrial tempe- rature is a most important branch of science. It may be doubted whether it has hitherto been cultivated in the right way, and whether local and minor anomalies have not been allowed to conceal the general laws which we should first seek to attain. It is quite certain, that the causes producing the inflexions of the isothermal lines are of the most irregular and unmathe- matical character, such as the boundaries of coasts and the like. Still we think that the time may not be far distant when we shall have isothermal charts as superior to those now existing, as Gauss’s magnetic charts, deduced by skilful artifices from a limited number of good observations, are to those of Halley in the last century. D. Decrease of Temperature with Height}. 51. Part of what properly belongs to this head will be more conveniently treated of in considering the general question of the temperature of the globe and its appendages. 52. There is little doubt that the decrement of temperature is not uniform, but slower as we ascend. It is to this, pro- bably, that we are to ascribe the greater values of the height due to 1° of decrement in equatorial than in temperate climates: thus, Boussingault found 26° c. of decrement for 4800 metres of ascent in the tropics, or . . 1°c. for 184 met. Col. Sykes, in India, on a height of 8500 ft., finds 1° F. for 332 ft. of ascent §, or . . : 5 RP gore a =) Whilst Saussure’s mean value in the Alps is : § j erie yy 154 -'53 Eschmann on the Rigi. F Sede Copibet ag Wy Uae As * Ann. de Chim. liii. Annuaire, 1836, p. 263. + Théorie de la Chaleur, p. 508, &c. t See First Report, p. 218, and Mahlmann, p. 53. § British Association, Fourth Report, p. 568. 58 REPORT—1840. M. Boblaye in Greece. d - 1%. -for=150!met: 38 observations collected by Ramond 1°c. ,, 164:7,, And for Gay Lussac’s aérostat alone 1°c. ,, 184 ,, as we might expect, from its great elevation*. 53. We have reason to believe, that in high latitudes the decrement is less rapid than in low ones; and M. Aragof has called particular attention to cases in which an actual inversion of the usual law occurs in the latitude of Spitzbergent, and on Arthur’s Seat, near Edinburgh, during extreme cold§. 54. The decrement of temperature in the atmosphere, with reference to its constitution, has been considered in a lengthened series of papers, of which we cannot attempt an analysis, by M. Biot, lately published in the Comptes Rendus de ? Académie des Sciences de Paris, and in the Connaissance des Tems. 55. It has been considered in a more restricted point of view by Prof. Challis|], who has deduced from the properties of air, with regard to specific heat, a fall of 1° Fahr. for 186 feet, which is about a half too rapid. Mr. Lubbock, on the other hand, proceeding @ posteriori from Gay Lussac’s aérostat, has generalized the connexion of temperature and pressure so as to find the height of the atmosphere]. 56. Any attempt, however, to connect the temperature and density of the atmosphere by laws such as regulate a laboratory experiment, must fail, in consequence of the incompleteness of the data. The increased specific heat of rarefied air is by no means the only cause of the diminished temperature of the higher regions of the atmosphere**. The higher the stratum, the more transcalent the medium which separates it from the planetary spaces, and therefore the freer will be the radiation in * To convert metres for 1° cent. into English feet for 1° Fahr., use the con- stant factor 1°8227 [log. 9:26072]. + Comptes Rendus, vii. 206. t Observed by Captains Sabine and Foster. § Observed by Dr. Lind, 31 Jan. 1776. Phil. Trans. 1777. || Cambridge Transactions, vol. vi. q On the Heat of Vapours, p.21. Lond. 1840. ** On the specific Heat of Gases, see Dr. Apjohn’s experiment by the use of the moist bulb hygrometer, (Brit. Assoc., Sixth Rep., Sect. Proceedings, p. 33,) and Suerman’s Thesis, De Calore fluidorum elasticorum specifico, 4to. Trag. 1836, for which I was indebted to the ever-ready kindness of our late associate Dr. Moll. In these essays we find a new proof of the inexhaustible ingenuity by which philosophers have endeavoured to make amends for the practical dif- ficulties of the direct problem: it is curious to see one and the same question treated, now by the aid of the calorimeter, now by observing the tone of an organ-pipe, and now by a dew-point experiment! Unfortunately, we cannot add that these various methods give the desired concordance of result. Re- gnault’s are the latest experiments on the specific heat of simple{bodies. Ann. de Chim. \xxiii. 1. (1840.) SUPPLEMENTARY REPORT ON METEOROLOGY. 59 that direction. Besides, the atmosphere is no doubt a medium of that description, which permits solar radiation to pass much more freely than heat which has combined with the materials of the globe at a low temperature; hence the surface of the globe may be considered as a true accumulating source of heat, the further we recede from which the greater will be the cold*. 57. A just apprehension of these circumstances will serve to explain the modifications of this phanomenon, as well as the phenomenon itself. This I have lately endeavoured to do, and to show the accordance of the theory with factst. It is known, from experiment, that the decrement of temperature is most rapid in spring, and least so in autumn. This appears, both from the reduced observations on the Pentland Hills, near Edinburgh, alluded to in my last Report (p. 219), and from those on a great scale, conducted so long at Geneva and the Great St. Bernard{. I have shown that this arises from the following peculiarities of the annual curves at two stations at different elevations; (1.) the curve at the upper or colder station stands wholly below that at the warmer one. Hence were these two curves similar, and their epochs the same, the difference would be constant. But (2.) the range at the upper station is less than that at the lower one; hence the summer difference of temperatures is on the whole greater than the winter difference, which we know to be the fact§. (3.) The maxima above occur later than those below, so that the whole colder and flatter curve is shifted to the right hand, and hence the epoch of maximum difference precedes the epoch of maximum tempera- ture, according to a law which I have investigated in the paper referred to. 58. The diurnal curves correspond to the annual curves in the two first particulars, but not in the last. I have attempted to explain the cause of this difference, and to show that, in point of fact, the epoch of the diurnal curve at the higher station is (up to a certain height at least) accelerated upon the lower one instead of the reverse, and that consequently a re- tardation of the maximum difference upon the maximum tem- perature occurs, which is really the case||.. A clear apprehen- sion of the progress of temperature in the atmosphere and * See on this subject Fourier, Mém. de l’ Académie des Sciences, tom. vii.; Ann, de Chim. xxvii. 155 ; Saussure, Voyages dans les Alpes, 4to, tom. ii. § 932, &e.; Kamtz, Lehrbuch, ii. 128; Pouillet, Comptes Rendus, vii. 49. {+ Edinburgh Transactions, xiv. 489 (1840); and Jameson’s Journal, October 1840. { Dove’s Repertorium, iii. 337. § See First Report, p. 219. Kamtz, Lehrbuch, ii. 140. || Saussure, Voyages, iv. § 2050. Kamtz in Poggendorff, xxvii. 345. 60 REPORT—1840. earth leads to many interesting and important practical con- clusions, upon which we cannot now dwell. 59. Whilst we admit the phenomenon of the decrease of temperature with height to be the normal one, and other cases exceptions, we must not omit to mention an important class of real exceptions, which deserve particular study. 60, The superior radiating power of Earth to Air is the cause of the seemingly preternatural depression of the tempera- ture of the ground in clear evenings observed by Six, Wilson, and Pictet, and so well applied by Wells to the theory of dew. It is evident, that under the circumstances which favour the development of the cause (viz. Radiation), the effect must extend more or less above the surface; and, consequently, up to a certain point the temperature will zzcrease with height. This question has lately been treated of in an interesting paper by Prof. Marcet*, who has arrived at the following con- clusions :—1. It is a constant phenomenon about the time of sunset, except in the case of violent winds. 2. It attains a maximum immediately after sunset. 3. The increase of tem- perature with height extends to 100 or 110 feet at the most. 4. It is most conspicuous when the ground is covered with | snow. 61. This leads us directly to the important subject of E. Radiationt, whether solar or terrestrial; in its bearings, perhaps, the most important and interesting at present connected with Meteoro- logy. We speak now principally of instruments and primary results; in the next section, of conclusions to be drawn from them in connexion with great cosmical questions. 62. The earth acts by absorbing radiant heat from the sun and (perhaps) other heavenly bodies ; and it radiates it again according to new laws towards space. Each of these effects, and the modifications which circumstances introduce into them, may be made the subject of separate experiment. 63. Since a thermometer with a blackened ball absorbs more solar heat than a bright or transparent one, it was natural to suppose that the difference of indication of two such instru- ments might be considered as a measure (at least a relative indication of the force) of solar radiation. ‘The stationary dif- * Mémoires de la Société de Physique, &c. de Généve, tom. viii. (1838). + See First Report, p. 222; Mahlmann, p. 64. I think it unnecessary to say anything of the progress of our knowledge of Primary Physical Laws of Radia- tion, because that is to be made the subject of a special report by Professor Powell. SUPPLEMENTARY REPORT ON METEOROLOGY. 61 ference of such instruments was therefore observed by Lam- bert*, Lesliet, and others. 64. It is plain, however, that this indication can only be con- sidered to be comparable with itself so long as all external cir- cumstances besides solar radiation remain the same. ‘This Saussure well showed by one of his admirable experiments f, in which, by properly defending the thermometer from wind and common radiation, he raised its temperature in the sun to 190° Fabr. Sir John Herschel first pointed out that the momentary effect of the sun and other combined causes, in affecting the temperature of a thermometer, diminished by the momentary effect of those other causes acting separately, is the true relative measure of the force of the sun’s rays. The first notice I have met with substantiating Sir John Herschel’s claim to the ap- plication of this principle (which has since been rather un- scrupulously adopted abroad with a slight change of form), is in a paper by the late Dr. Ritchie, in the Edinburgh Journal of Science for 1825 §, where he gives an extract from a letter of Sir John Herschel, who, ina few words, sufficiently describes the instrument and its principle. Full instructions for its use have lately been printed by the Royal Society ||; it is called an ac- tinometer. 65. The actinometer scale is an arbitrary one, obtained by direct comparison of one instrument with another; and so satis- factory is this kind of observation, that, from direct experiment, I am satisfied that the value of the actinometric degrees may be obtained within ;1,th of the amount of solar radiation. It is very singular, that Sir John Leslie, with his marked sagacity, should not have perceived that his mode of graduating photo- meters, by first converting them into hygrometers ], is radically erroneous; and accordingly I have found that, when his instru- ments are compared, after being constructed with the utmost care, they do not even approach to agreement except at 0°, unless they are of the same dimension, and in every respect similar ; but absolute identity in size, material, and arrange- ment, it is beyond the power of art to obtain. Careful experi- ments, which I have likewise made with this elegant instrument under different skies and in different climates, compel me to conclude, that though in certain very uniform circumstances its relative indications may be really of value, yet in a wider * Pyrométrie, p. 158. 4to. Berlin, 1779. + Essay on Heat. Lond. 1804. + Voyages dans les Alpes, § 982. § Vol. iii. p. 107. | Report of Committee of Physics, &c. 1840, p. 61. q Essay on Heat, p. 421. 62 REPORT—1840. point of view they do not even afford the slightest approxima- tion to the truth. 66. It does not, however, follow that the indications of the photometer are of no value, or that observations with it should be discontinued. There are some constant peculiarities in its action, so remarkable, as to suggest very interesting investiga- tions. The effect of the reflected light of the sky is always exceedingly intense; so much so, as to give rise to the most paradoxical effects with regard to the intensity of solar radia- tion, if neglected. Thus I have found the whole effect of the sun and sky in a bright April day in this country, when many white clouds were present, not very inferior to that of the most piercing sunshine of the most sultry day of the south of Europe, unaccompanied by a single cloud. What would be the indica- tions of the actinometer in these circumstances I am unable to state. M. Kamtz found, on the summit of the Faulhorn, that the direct solar effect on Leslie’s photometer was equalled, and often exceeded, by that of the diffuse atmospheric in- fluence*. 67. Sir John Herschel has lately proposed to render his scale an absolute one, denoting by an actine ‘‘ the intensity of solar radiation, which, wholly absorbed at a vertical incidence, would suffice to melt a sheet of ice one-millionth of a metre in thick- ness in one minutet.”’ With an actinometer, which marked 29°5 as the maximum effect which he had observed in Europe, Sir John Herschel found the solar radiation at the Cape of Good Hope to attain 48°°75 of the same scale, the intensities being in the exact proportion of those numbers f. 68. M. Pouillet, of Paris, described, some years ago, an ap- paratus for measuring solar radiation, in which the errors of other statical contrivances were in a good measure avoided, by en- closing the thermometer in an envelope maintained at 0° c., with the exception of a small hole, which exactly admitted the direct rays from the solar disc§. Since that time, however, he has adopted Herschel’s dynamical method, which he has applied to a modification of the actinometer, which he terms a pyrhelio- meter; reserving (rather unfortunately I think) the term acti- nometer, which was already so fitly appropriated, to a separate apparatus for measuring nocturnal radiation. These instru- ments and their applications are described in an ingenious and interesting memoir read to the Academy of Sciences 9th July, * Lehrbuch, iii. 14. + Poggendorff, xli. 559. Royal Society’s Report, p. 67. + Comptes Rendus (Paris), iii. 506. § Elémens de Physique, 1832, tom. ii. p. 703, fig. 356. i ST SUPPLEMENTARY REPORT ON METEOROLOGY. 63 1838, printed in the Comptes Rendus*, and also privately cir- culated. 69. A question of very great importance in meteorology, and one of the first which radiation experiments were employed to determine, is the proportion of incident solar heat which is absorbed in its vertical passage through the atmosphere. In the acute, learned, and original work of Lambert on Photo- metry, published in 1760, (and now, I know not why, extremely scarce,) this question is fully discussed; formule are investi- gated for the total loss of light at any altitude, according to an assumed law of density, (which had already been done by Bou- guer ft, who first suggested the method,) and from a comparison of intensities at two elevations, the total loss in the atmosphere by a vertical transit is ingeniously deducedt. From experi- ments made at Coire with blackened thermometers, Lambert deduced the loss of light or heat by a vertical transit through a clear atmosphere to be about ;4ths of that incident on the ex- terior boundary§. Bouguer had estimated the loss of light at only one half as much. ; 70. Laplace || investigated the law of extinction of light in the atmosphere, and showed that it may be made to depend ap- proximately on the measure of refraction at any angle, bya very simple formula. He employed Bouguer’s constant for 0° of zenith distance. ; 71. Sir John Leslie made experiments on the principle of Bouguer and Lambert, with his photometer placed in a position which equalized as much as possible the cooling causes, and admitted the direct heat of the sun4. The results are con- tained in the article Climate, in the Encyclopedia Britannica, from which it appears that he estimates the loss of heat by absorption at {th of that vertically incident. 72. Professor Kamtz, who has done full justice to Leslie’s ele- * Mémoire sur la Chaleur Solaire, sur les pouvoirs rayonnants et absorbants de l Air Atmosphérique, et sur la Température de l’ Espace.— Comptes Rendus, vii. 24, t+ Traité d'Optique, &. 4to. 1760, p. 306. Bouguer restricted his method to Be cioparicon of the intensity of lunar light at different elevations with wax candles, t Lambert, Photometria, sive de Mensura et gradibus Luminis, Colorum, et Umbre, p. 392, &c. § Photometria, p. 397. Compare Pyrometria, § 283. || Mécanique Céleste, iv. 282. {] Sir John Leslie himself gives no account of the circumstances under which the observations were made, but I learn from his assistant, that the photometer was placed under the revolving dome of the Edinburgh Observatory, the slit being turned towards the sun, and that it was observed very frequently at dif- ferent hours. 64 REPORT—1840. gant instrument*, and who has endeavoured to separate from its indications that part which is due to reflexion from the at- mosphere, finds by it, that at the summit of the Faulhorn, nearly 9000 feet above the sea, 30 per cent. of the vertical rays are already lost. With Herschel’s actinometer (calculating al- ways observations at different elevations by Lambert’s formula), he obtains only 26 per cent. of loss at the Faulhorn, or 32 per cent. at the level of the sea. This was in perfectly clear weather. 73. M. Pouillet, employing likewise Lambert’s formule, and the modification of the actinometer already mentioned, finds, at different seasons of the year, an absorption varying from 21 to 28 per cent., at a vertical incidence at Paris. 74. Saussure seems first to have thought of comparing directly the intensity of solar heat at the top and bottom of a mountain, and he contrived a heliothermometer for that purpose; and by experiments on the Cramont, to the south of Mont Blanc, he actually proved the increased intensity of the solar rays as we -ascend, notwithstanding the diminution of temperature; un- doubtedly a very remarkable experiment for the period +. - 75. In 1832, Sir John Herschel kindly pointed out this pro- blem to my attention, and furnished me with two actinometers. I had the rare. good fortune to obtain the aid of Prof. Kamtz in making directly comparative experiments at the top and bottom of a column of air 6500 feet high, of known density, tempera- ture, and humidity, under the most unexceptionable circum- stances in point of weather. A provisional reduction of these experiments has given me 29 per cent. for the vertical loss at the level of the sea, a near agreement with the 32 per cent. in- dependently determined by the method of Bouguer and Lam- bert with the same instrument at the same time. 76. Collecting these various results, we have for the absorp- tion of incident solar heat traversing the atmosphere vertically in clear weather, the following fractions (incident heat = 1) :— BORNE \ sh, ena) ata Goh csp he ata eri ee ete ae he ae HS EER ais OR GONE aE con nae MRC ee aes er ee rene LR LL oUt a oh ee aS ae” Kamtz and Forbes”, , . -: . s@9 bE OR ie Me Mae ems Mean, omitting the two first . °277 * Lehrbuch, iii. 10, &c. + Saussure, Voyages, 4to. iti, 310, and note. + It appears from the remark of M., Pouillet, p. 8 of his Memoir, that he would make the fraction even lower for a perfectly pure sky. SUPPLEMENTARY REPORT ON METEOROLOGY. 65 77. Another method of measuring, or at least comparing the intensity of solar radiation, would be by the use of photographic aper*, 78. The next problem which radiation experiments may be expected to solve, is the quantity of heat actually received from the sun in a year on the surface of the earth. According to Pouillet’s Jast estimate, this amounts to a quantity of heat capable of melting 31 metres’ thickness of ice all over the globet+. Such estimates must be received with considerable diffidence. 79. The excess of heat received during the day is given off at night, or rather there is a perpetual radiation of heat from the globe towards the celestial spaces, which, granting the con- stancy of climate from age to age, must exactly equal the quan- tity of heat received. Observations of this kind may be made in various ways. The simplest is by exposing a thermometer to the aspect of the open sky, laying it on some freely radiating substance, such as snow, wool, or swandown. In this manner were conducted the experiments of Six, Wilson, and Wells. Wells noticed a difference of two thermometers, one in air, the other placed on swandown, amounting to 8°3 centigrade de- grees{ (15° F.). Boussingault, in his observations amidst the- Andes, has recorded a depression of 6°1; but the radiating thermometer was laid simply on turf, the other was suspended in the air at a height of 1°6 met. (5 ft. 4in.)§. His observations were carried to a height of 4600 metres, where we should expect the effect of nocturnal radiation to be greatly increased, owing to the excessive transparency of the atmosphere. The same author mentions the curious fact, that to defend their crops from the intensity of the nocturnal cold, the natives of South America often make artificial clouds by means of smoke. 80. Leslie applied his differential thermometer to the measure of radiation by exposing one ball in the focus of a parabolic mirror, which he then called an ethrioscope. The conduct of systematic experiments of this kind is a matter of considerable difficulty. The only continuous series with which I am ac- quainted were made at Geneva during several years succeeding 1836, and published amongst the regular and excellent obser- vations preserved in the Bibliotheque Universelle, a journal in * See Herschel, Phil. Trans. 1840, p. 46. “‘ Description of an Actinograph or self-registering Photometer for Meteorological purposes.” ¢ Mémoire sur la Chaleur Solaire, p. 9. His former estimate was 14 metres only (see First Report, p. 222). £ Arago, Annuaire, 1836, p. 261. See also Annuaire, 1838, p. 214, &c. § Ann. de Chim. lii. 260. VOL. 1x. 1840. F 66 REPORT—1840. which, during its long existence, marked attention has been given to the science of meteorology*. It does not appear, from the writings of Sir John Leslie himself, that he had ever obtained any very definite results by the use of the ethrio- scopet. ‘The action of the reflecting mirror seems not to be fully understood, at least so M. Pouillet assertst{. I am unable, from experience, to verify his statement, which leaves, however, some ambiguity. M. Pouillet employs a vessel stuffed with swanskin (peau de cygne), capable of having its orifice directed at pleasure, and having a radiating thermometer in its centre. By ascertaining the effect upon this apparatus of a surface artificially maintained at a given temperature, he deduces the mean radiating temperature of the atmosphere considered as an indefinite concave. But this brings us to general questions of great interest and importance. F. Proper Temperature of the Globe and of Space§. 81. I forbear to repeat what I have formerly said respecting the proofs of the proper temperature of the interior of the earth. I confine myself to a statement of the very important advances since made, both in experimental researches and in the induc- tion of laws. 82. A few fundamental experiments are sufficient to maintain Fourier’s position, that the interior heat of the earth exercises no perceptible influence on its present climate; we are there- fore left to consider the effects of heating and cooling influences wholly external. 83. The imperfect transparency of the atmosphere stops a not -inconsiderable share of the solar rays, which are therefore ex- pended in heating it directly. But the major part reach the surface, and their effect being there concentrated (whilst in their transit through the atmosphere it is spread over a vast mass of air), the effect is incomparably more intense than else- where. The bounding surface of the earth (or ocean) and air is therefore to be considered as a true source of heat. From thence it is distributed progressively downwards by CoNDUC- TION||, upwards by RADIATION and CONVECTION. The warmth * Bib. Univ., N.S., iii. 209, and subsequent volumes. Since the publication of the former report, we have to regret the loss of the late amiable Mr. George Maurice, principal editor of that journal. + Articles Curmate and Metecoroxoey, Encyclopedia Britannica, New Edit. t Mém. Chal. Sol., p. 32. § First Report, p. 221; Mahlmann, p. 67, &c. || Even in water. See the interesting and conclusive experiments by M. Despretz, Comptes Rendus, vii. 933. SUPPLEMENTARY REPORT ON METEOROLOGY. 67 of summer and the winter’s cold are gradually propagated both upwards and downwards; and, in either case, with a diminishing intensity according to known laws. The annual curve of temperature in the ground is rapidly retarded and flattened, until, at a moderate depth, (60 to 100 feet, depending upon the conducting power and specific heat of the soil,) it sensibly coincides with a straight line, or the influence of seasons disappears ; and the same takes place in the atmosphere at a great and unknown elevation. 84. The general principles of the communication of heat have led to the conclusions, 1. that the annual range should diminish geometrically as the depths below the surface increase arith- metically ; 2. that the retardation of epochs increases uniformly with the depth*. 85. Both these conclusions of theory have been very satisfac- torily verified by the experiments mentioned in the former re- port t, and extended since. And what is still more important, the verification of these two simple laws includes the introduction of certain constants, which may thus be determined a posteriori, and the general solution of problems of terrestrial conduction obtained. 86. Instead of merely citing the formule in which the ex- pressions of the constants of our globe and system are involved, and which are found to express approximately the thermo- metric conditions of the strata of our globe near enough to the surface to be directly influenced by climateric changes, we will endeavour to trace, very generally, the Aind of process by which mathematicians have attempted to reduce to law these most complicated and involved series of causes. In doing so we have a twofold object, which seems peculiarly congenial to the nature of such reports as the present; first, to extricate from a chaos of symbols (which would deter most persons from even tracing the connection of the data assumed, with the results announced), such results as apply immediately to the physical investigation ; and secondly, to consider how far the really fundamental conditions of the problem have, or have not, been sacrificed to render the mathematical investigation practi- cable at all. * See the original works on Heat of Fourier (particularly Mém. de l'Institut, 1821-22, p. 168) and Poisson, the elementary work of Prof. Kelland, and the Report by Prof. Whewell, on the Mathematical Theory of Heat. British Association, Fifth Report. + P. 221. The experiments on buried thermometers, near Edinburgh, were made in the grounds of Mr. Ferguson, of Raith, by his permission, but were suggested and directed by the late Sir John Leslie. See Whewell’s Re- port, p. 30; see also article Cuimarr, Encyclopedia Britannica. F2 68 REPORT—1840. 87. The work in which the rigorous comparison of theory with experience in this most intricate inquiry has been most insisted on, is that of M. Poisson, of whose mathematical attainments it would be equally unnecessary and unbecoming in me to speak ; any criticisms I have to offer will therefore be confined to the second of the heads I have noticed above; and to his writings * I will chiefly confine my attention. 88. So far as the effect of soLAR HEAT is concerned, the a pri- ort solution of the problem of the temperature of any part of the earth’s surface may be thus imagined :—(1.) The whole quantity of sunshine which falls on any part of the earth’s surface in the course of a year is to be found, and also the law of its variation of force at different seasons. (2.) The part of this heat which becomes effective in heating the earth’s crust is to be found by multiplying the amount by a constant depending upon the absorbent power of the surface. (3.) This quantity of heat thus reduced is propagated towards the interior, accord- ing to the laws of conduction, which again pre-suppose the knowledge of two constants proper to each soil, namely, the Conductivity and the Specific Heat. 89. (1.) The measure of the quantity of sunshine received by any place in a year, and its distribution at different seasons, has been a favourite problem with mathematicians+. In ultimate analysis, it depends of course on the astronomical elements which affect the progress of the seasons, viz. the obliquity of the ecliptic(y), the latitude of the place(u), the excentricity of the earth’s orbit(a), and the longitude of the sun’s perigee(a) ft. But there are also elements quite as important as any of these ; the imperfect transparency of the air and its varying thickness, owing to differences of obliquity of the transmitted rays, and the condition of opacity depending on the weather. Neither of these are insignificant, neither of them compensatory; both may be considered as functions of the hour-angle and fraction of the year, and the second is besides subjected to the most capricious changes. Yet of these elements theory has hitherto taken no account, and consequently the expression for the quantity of sunshine obtained, in terms of astronomical con- stants, with so much labour, we must hold to be nearly useless as a physical datum. It is vain to say, with M. Poisson§, “Les lois d’absorption de la chaleur solaire 4 travers l’at- mosphere, les variations diurnes et annuelles sont également * Théorie Mathématique de la Chaleur, 4to. Paris, 1835, chap. xii. Sup- plément, 4to, 1837, and Comptes Rendus, iv. 137. + See a list in Kamtz, Lehrbuch, i. 60. t In Poisson’s Notation. § Théorie, p. 475. SUPPLEMENTARY REPORT ON METEOROLOGY. 69 inconnues, et l’on peut seulement supposer qu’elles sont peu considérables.’ We know, on the contrary, that they are so considerable, that, estimating the loss of radiant heat by a vertical passage through the atmosphere (7 6.) at only twenty- five per cent., at an angle of elevation of 25° the force of the solar rays would be reduced to ahalf, and at 5° to one-twentieth part. We know, indeed, that the difference of the direct effect of a vertical and a horizontal sun is due to this cause alone, exag- gerated, of course, immensely by the variable meteorological state of the atmosphere, which again is a function of the lati- tude. 90. (2.) The receptive power of the surface is a datum which we find it very difficult directly to determine, and which, since the quantity of sunshine cannot (as we have seen} possibly be directly computed, must be inextricably mixed up with it. It might be a question, whether, by covering a tolerably extensive surface of soil, in which thermometers are inserted, with a com- position of known superficial conductivity, this element might not become known. 91. (3.) The specific heat (c)and conductivity (4) of the soil are also inextricably mixed up together in the analysis; but either becoming known, the other may be inferred from thermometric observations carried below the surface. The specific heat seems that best adapted for laboratory experiments ; M. Elie de Beau- mont has assigned 0°5614 for the value of ¢ (that for an equal bulk of water being = 1)*, proper to the soil at the Observatory of Paris. 92. To obtain the conductivity of the soila@ posteriort, it is for- tunately not necessary that the preceding theoretical estimation of the distribution of sunshine should be correct ; but there are other estimates into which it essentially enters, and which must therefore be received with corresponding caution. To facilitate reference to M. Poisson’s work, I will show how the simple and very satisfactory observation of maximum and minimum tempe- rature of the earth’s crust at given small depths (above the inva- riable stratum) may be made to yield a knowledge of some of the constants above referred to. 93. Let the excess of annual maximum above annual minimum temperature at a depth p be expressed by A, 5 then log A, = A+ Bpt In which A of course denotes the log. range when p = 0 or * Poisson, Supplement, p. 4. + M. Quetelet puts under this form M. Poisson’s equation.—See the memoir referred to below. 70 REPORT—1840. at the surface, and B determines the common ratio of the geo- metrical progression according to which the range diminishes. From observations with two thermometers at different depths, A and B may be obtained @ posteriori. 94. Now when we consult M. Poisson’s work, we find that his equation (23.), page 497, whichis equivalent to the preceding one, is thus composed. The quantity A, on which the superficial range depends, contains (1) astronomical constants of climate y, &, &, @ already mentioned; (2) a temperature A depending on the mean force of the solar rays which have traversed the atmo- sphere and entered into combination with the earth’s surface by absorption at a given place*; (3) the constant of conductivity 4, and of specific heat ce. 95. The co-efficient B, on which the rate of diminution of the range depends, is fortunately a very simple quantity, involving neither astronomical constants, nor those proper to the superficies. It is, in fact, an absolute number multiplied by, / a. and from a knowledge of it (by observations with two or more thermome- ters) this quantity may be very readily and accurately deter- mined ; and it affords the only unexceptionable manner of ascer- taining the conductivity of the earth’s crust on a large scale. Observations to this effect have, from time to time, been made by thermometers plunged more or less below the soil; first, by Ott of Zurich, in 1762+; secondly, by Leslie near Edinburgh ; thirdly, by Herrenschneider at Strasbourg}; fourthly, by Muncke at Heidelberg§; fifthly, by Rudberg at Upsala; sixthly, by Arago at Paris; seventhly, by Quetelet at Brussels. An ad- * Poisson, p. 480, where the definition of / is “ Une température constante proportionelle & l’intensité de la chaleur solaire, telle qu'elle est a la distance moyenne de la terre au soleil et aprés avoir traversée l’'atmosphére pour arriver au point O.” It must not, however, be forgotten, that it includes ¢, a constant of superficial absorption, and therefore varies from one point to another. See Poisson, p. 500. The quantity / is one of the most troublesome clearly to ap- prehend, and the dispersion (and sometimes permutation) of symbols throughout so large a work contributes to the ambiguity. I will therefore add, that in the ce SET: = x) a? ¢ is a constant of absorption for a given soil, but which may vary with the incidence of the rays (p. 474) ; S is the product of an element of surface, and a quantity of heat in the condition in which the atmosphere has transmitted it (p. 475); a and a, denote the proper superficial radiating power of the point O under consideration, and the cooling effect due to the contact of air (p. 849). The product of h by Q (see Art. 105, note) measures the thermometric efficiency of the solar rays in raising the climateric temperature of the spot (p. 518). + Lambert's Pyrométrie, p. 356. } Imperfect; only one thermometer. § Gives only the epochs. value of h, page 480, namely, SUPPLEMENTARY REPORT ON METEOROLOGY. 71 mirable abstract and analysis of all these observations has been made by the last-named indefatigable observer, in a special me- moir on the subject*, which we could hardly abridge without transcribing, and will therefore state chiefly the results with respect to the quantities A and B mentioned above. The fol- lowing are the principal results in a tabular form, it being un- derstood that in most of these cases no correction has been ap- plied for the temperature of the liquid in the stem of the ther- mometer and between the bulb and the surface of the ground. or uo | 3 Ss| ig eaene| de. oss an < — Place 5 #| 2 | Extreme | 33~ 3 g|° aS pk — Sen . Be|/m2| Depth |sSegs| 528 — const. ess 35/8 Brees | Bam Ny gee r=] L23aa Po [-7as) & ga a 4 feet. feet. days Zurich .......0000- 8 | 43 | 6(Fr.?) 71 1-217 — 038 5 Edinburgh ...... 4 |2 | 8(Eng.)} 58 1-068 — 052 7 Strasbourg ...... 1 | 3 {15 (Fr.?) 81 1:279 — -040 4/3 1-292 — 053 4 . Ae 96. The following observations have been made at Edinburgh, under my direction, at the expense of the British Association{, which, as well as those at Brussels, are completely corrected for the temperature of the liquid in the stems :— Edinburgh In Trap Tufa.| 4 | 3 | 24(Fr.)| 55 1-141 — 057 6:8 — Loose Sand.| 4 oa] PS ee 66 1-192 — 048 6:2 — Sandstone..| 4 | 3 | — 96 1-080 — ‘032 4:0 97. These latter observations show very clearly the effect of soi/ in determining the velocity of propagation of heat which mainly depends upon the value of B, from which too the conductivity for heat of three very different geological formations may be accu- rately determined, so soon as the specific heat shall be known. 98. Observations of the same kind with the preceding have * Mémoire sur les Variations Diurne et Annuelle de la Température, &c., 4to, Bruxelles, 1837. (From the Mémoires del Académie de Bruxelles, tom. x.) + These observations have now been continued for three additional years, and the partial results are contained in the Bulletin de l’ Acad. de Bruxelles, and the Annuaire de l'Observatoire. Since this report was read, I have received M. Quetelet’s Systematic Reduction of the Observations at Bruxelles for 1837, 1838 and 1839. The results agree extremely well with those of previous years, and establish the formula of Art. 93. with remarkable precision. Jém. de V Acad. de Bruxelles, tom. xiii. 1840. t See Eighth and Ninth Reports, and Atheneum for September 1839. 72 REPORT—1840. been instituted at Bonn by Prof. Bischoff*, and at Freiburg in Saxony by Prof. Reicht; but of these, so far as I am aware, only imperfect notices have yet appeared. 99. The epochal retardations for the annual curves at the depth of a few feet follow, generally speaking, asimple law, for they are propagated uniformly downwards with a velocity which is easily connected with the constants proper to the soil determined from the range at two given depths, as justexplained{. It must not be concluded, however, that the epochs of earth-temperature at the surface coincide with those of air-temperature in the ad- joining stratum. The difference of epoch may be obtained in terms of the conductivity and superficial characters of the solid stratum§. But the complete expression for the epoch at any depth in terms of the dates of maximum and minimum at some other depth, and of the constants of conductivity and surface, derived from two observed ranges, is so complex, that so far as I know, no attempt has been made to verify M. Poisson’s for- mule except in a single example by himself, taken from M. Arago’s observations]|. 100. It is a matter of some practical difficulty to find the precise period of maximum and minimum temperature from ob- servations at or near the surface, on account of the accidental fluctuations which occur, especially near the time of minimum, and which, even at a depth of three feet, produce in this climate an uncertainty sometimes of a week or more. 101. I have already stated, in the preceding table, the results * Warmelehre von G. Bischoff, 8vo, 1837, pp. 100, 392,507. The observa- tions were not made with long-tubed thermometers having their scales above ground, but by sinking bottles of water in-wooden tubes to a certain depth, drawing them up rapidly, and observing their temperature. The observations were carried to a depth of 36 feet. + Bischoff, ibid, p. 512. t Poisson, p. 432. If X be the range at a depth x, and X! at depth a!, and a the retardation of epoch due to the increased depth from a to a’, the following relation holds, X'=Xer™ r m being a constant and e the base of Napier’s logarithms. Ibid. iP. 502-3. The coincidence is not so remarkable as a cursory inspection would suggest; there are not four coincidences but only two—the data and quesita being reversed. The coincidence, such as it is, perhaps proves too much ; for M. Arago’s observations are not corrected for the temperature of the stem (‘afin de pouvoir faire usage des observations non corrigées que M. Arago m’a communiquées, je supposerai que ces corrections soient peu considérables, ” p- 500); it is certain, however, that for the larger thermometers, where the range is /east, and the correction greatest, the epochs must be (perhaps most materially) affected. The scientific world anxiously looks for the extended and reduced observations of M, Arago. SUPPLEMENTARY REPORT ON METEOROLOGY. 73 of different observations on the rate of progress of heat into the soil, especially as depending on its geological character, a com- pact sonorous sandstone transmitting heat at the rate of one foot in four days, whilst in loose sand (the same ingredient) it required 6:2 days. The following tables illustrate the varying retardation and proportionate diminution of amplitude (or range) at different depths*. s8 a Maximum. Minimum. Range. Se eae ee eel Bayt d Delos bye ifs te dowiasne ed BS oa | Sab Babe tenes tecgt Ki Trap. Sand. Sandst. Trap, | Sand. Sandst. Trap. ;} Sand, | Sandst. 3 | Aug. 5| Aug. 2| Aug, 7 || Mar. 6] Feb. 28! Feb. 23 ||9° -67c|11°-03c|9° -67c 6 | Sept. 1| Aug. 25| Ag.19 | Mar. 20 | Mar. 22 Mar. 3 \6° "12 | 8°-05 |7° -68 12 | Oct. 15| Oct. 8] Sept.14 || Apr. 25 | Apr. 22 | Mar. 26 |/2° -85 | 4°-03 |5° -01 24 | Jan, 6} Dec.31| Nov. 6 | July 15} July 1} May 12 |/0°-75 | 1°-00 |2° -20 102. What we have now stated respecting annual variations of temperature, is found to be true, mutatis mutandis, for diurnal ones. Theory shows that the depth at which periodic fluctua- tions sensibly vanish should be (ceteris paribus) as the square roots of their periods, and this is found to be nearly the case in point of fact; the diurnal oscillation being nearly as insen- sible at a depth of three or four feet, as the annual one is at nine- teen (or / 365) times the depth, or at 60 or 70 feett. M. Que- telet has made a most extensive series of observations at small depths, and he finds the diurnal heat-tide to penetrate at the rate of 1 decimetre (4 inches) in 2°8 hours nearly, in the month of Marchf. 103. We now hasten to state a few other conclusions which have been attempted to be drawn from the very important class of observations of which we have recently spoken. Did we possess, in the actinometer or any other instrument, the means of measuring the actual force of sunshine in any place at a given moment, insuperable difficulties would yet arise to the determination of the very important questions, “‘’To what extent does the direct solar influence actually contribute to produce the climate we enjoy?” and “ What would be the temperature of our globe without the sun?’’ It is difficult or impossible for us to take cognizance of the perpetually fiuctuating amount of solar heat, and to sum up the discontinuous amount of it du- ‘ting the year, allowing for intervals of darkness, atmospheric _ * These numbers are (excepting the epochs of minima, which are but two years) amean of three years. The temperatures are centigrade. + Quetelet, wt supra, p. 72. { Ibid, p. 68. 74 REPORT—1840. opacity, and cloudy weather; and even could this be accom- plished, we should yet want data for knowing what portion of the incident heat combines with the earth so as to affect the climate. M. Pouillet, we have seen, has estimated the total quantity of sunshine incident on our globe*, but this was irre- spective of modifications of weather, and of the variable quantity of sunshine in different latitudes. 104. A practical @ posteriori determination of this most im- portant meteorological element of the total quantity of effective solar heat, affecting the thermometric mean of any climate, has been suggested by M. Poisson. It seems well established by observations in the Caves at Paris, and by observations on the temperature of the earth at Geneva, that the mean air-tempera- ture and mean superficial earth-temperature agree at these places, though their extremes differ both in amount and epoch. If, then, we can by any means find the ¢otal effect of the solar rays on the superficial earth stratum, we may assume that to be the effect due to the direct action of the sun in raising the temperature of the place. 105. M. Poisson has accordingly attempted most ingeniously to connect the climateric effect of the solar rays with the indica- tions of thermometers sunk to small depths in the ground. From the value of the superficial range (whose logarithm is A in the expression of art. 93.) one of its factors 4 may be discovered, entering into combination with known or determinable quanti- ties, and this quantity A ist, for any given spot, a number pro- portional to the direct climateric effect of the sun’s rays which may be deduced from itt. Now let us admit the mathematical accuracy of this very intricate investigation, and the admissibility * Art. 78. t See art. 94, note. + The value of A of art. 93, 94, is the following (in Poisson’s Notation, 2bh : f page 497) : log D 37 sinwsiny — 2«Q), where a, y, #% are astronomical constants already mentioned. his the constant of art, 94. note. b is a constant depending on the superficial character of the soil, and also on its conductivity. D is a function of 6, of the specific heat of the soil, and of the longitude of the earth's perihelion. Q is a very complicated function of the astronomical constants which deter- mine the length of the day, and is one of a series of definite integrals of which the succeeding terms are neglected. By the combination of two observed values of A + B p (art. 93.) 6 and B are eliminated; the above expression contains only / and known quantities (Poisson, p. 499); and the product 4 Q expresses (p. 518) the number of degrees by which the annual mean temperature of the given place is affected by direct solar radiation. SUPPLEMENTARY REPORT ON METEOROLOGY. 75 of the approximations of calculation*, still we find little reason to trust implicitly to the results, however ingeniously obtained. We have seen (69.) that the effective action of solar radiation cannot be expressed simply by the quantity of heat which would fall on a square foot of the earth’s surface were the atmosphere removed ; but the absorption is very great even in the clearest weather, and therefore (even admitting a uniform distribution of vapours over the whole year, so that their opacity need not be considered as a function of the time) the quantity of solar heat depends on the thickness of the atmosphere traversed, and is therefore a function both of the hour angle and of the fraction ofa year. The integrals, therefore, expressing the discontinu- ous quantity of sunshine, are wholly unadapted to the physical conditions of the problem. 106. That 4 cannot thereby be rightly estimated, will appear from this consideration: viz. that the whole effect of sunshine can only be deduced from the annual range at a given depth (or at the surface) by the following reasoning. The winter-action of the sun may (it is assumed) be compared a priori with the summer-action of the sun, and the excess of the latter action determined; but the Effect due to this Excess being observed (viz. the annual range), the effect due to either of the constituent actions (summer or winter) may be found, which gives the whole climateric effect of the sun at any season, and hence its mean effect throughout the yeart. Now in applying this principle, it is clear that unless the @ priori estimate of the sun’s relative radiation in summer and winter be made on correct principles, a knowledge of the difference of effect due to the change of the cause will not lead to a correct value of the cause. In point of fact, a neglect of the absorption due to obliquity (not to mention the enormous excess of cloudy weather in the winter half-year) will inevitably lead to an under estimate of the proportion which the summer radiation bears to the winter radiation, and (as the difference between these effects is the quantity known) the value * So involved are these expressions, that the author himself has inadvertently ‘Made use of two identical values of one quantity, this same h, and quoted the coincidence as a proof of the accuracy of the formule and observations (p. 503-4). This he admits in the Supplément, page 72. + This at least is my understanding of the principles of solving the problem. The problem which Fourier has proposed (Mém. de I’ Institut, v. 167, &c.) is _ amuch simpler and also a less important one, viz. to find the quantity of solar heat alternately absorbed and emitted by the earth’s surface in the course of a year, which evidently does not include the permanent or mean heat derived from the sun, and which is subject to no annual change, but which would be dissipated were the sun extinguished. 76 REPORT—1840. of the constituent effects will also be wnder estimated, or the climateric effect of the sun will come out too small. 107. Such, indeed, is almost certainly the case. The climateric effect of the sun at Paris is estimated from the superficial range of temperature (deduced by Poisson from Arago’s experiments) to be only 24° cent.*. The mean temperature of Paris being 11° cent., there remains for the temperature which would re- main if the direct influence of the sun were removed, — 13° c. or + 9° Fahr., a result altogether improbable. Further, the thickness of a sheet of ice over the whole globe which would be melted by the entire annual action of the sun, would be, accord- ing to Poisson, seven or eight metres}, whilst Pouillet supposes it four times as greatf. 108. Fourier, in his remarkable Memoir on the Heat of the Globe§, had clearly shown that its superficial temperature depends on three causes, which may be kept wholly distinct. 1. Solar heat. 2. Temperature of space. 3. Internal heat. To these M. Poisson has added Atmospheric Heat, which, however, is merely that part of the solar heat absorbed by the atmosphere and communicated secondarily to the earth, independent of that received by direct radiation. 109. Since the Report of Prof. Whewell on the Mathematical Theory of Heat, to which we refer for what had been written on these subjects at that time, several new contributions to this interesting branch of science have been made, both theore- tically and experimentally ; I allude particularly to the publica- tion of Poisson’s Theory of Heat, and Pouillet’s Memoir before- cited. 110. Poisson’s Theory of ArmospHeRic Hear has met witha very just criticism, in almost every part of which I entirely agree, at the hands of Prof. Auguste de la Rive, of Geneva. His ob- jections are so ably and clearly stated, that so far as they antici- pate my own, it may be sufficient briefiy to state them, and refer to his article || for details. And first, as to the constitution of the atmosphere: Poisson{], adopting the reasoning of Fourier**, admits that the temperature of any part of the atmosphere must be determined by the equality of the heat directly received from the sun and indirectly from the earth, with that radiated abroad * Poisson, p. 518. + Poisson’s Supplément, p. 7. t Mémoire sur la Chaleur Solaire, p. 9. (See above, art. 78.) § Mémoires de l Institut, vii. 569 ; and Whewell’s Report, in British Associa- tion, Fifth Report, p. 30. \| Bibliotheque Universelle, Nov.—Dec., 1835. 4 Théorie, p. 448, &c. ** Mém. de l'Institut. vii. 584, &c. ee a i eee bee ae SUPPLEMENTARY REPORT ON METEOROLOGY. 17 in space, and in the adjacent atmospheric strata. Proceeding, however, to the mechanical conditions of equilibrium*, he infers that the temperature of the exterior part of the atmosphere must be prodigiously low, in order that it may have a definite termination, which condition of non-elasticity he calls liquefac- tion}, a term, the impropriety of which will sufficiently appear from the observations of M. de la Rive cited below. It is quite certain that an elastic atmosphere may be considered as rigor- ously limited, even wholly irrespective of the diminution of elas- ticity due to cold, and this without necessarily inferring an as- sent to the molecular constitution, from which Dr. Wollaston deduced the limitation as a necessary inference§. Hence, any hypothesis of extreme cold required to produce mechanical equi- librium in the higher parts of the atmosphere is devoid of sup- port. As to the actual extent of the finite atmosphere, this is a question on which experiments both direct and indirect leave us much in the dark; nor can the optical phenomena of twilight be cited with much confidence in such a case, the reflective power of rarefied air being a datum on which we want direct evi- dence ||. 111. The effect of the atmosphere upon the temperature of the globe, as treated of by M. Poisson, is twofold; namely, /irst, the modification of solar heat, which after combination with the air both radiates, and communicates heat by contact, to the earth; if the sun were extinguished, this heat would also vanish, al- * Théorie, p. 459. ’ + Théorie, p. 459, and Supplément, note D. p. 60; Traite de Mécanique, ii. 612. + “ Nous ne pouvons admettre que cet état du fluide soit analogue a l’état liquide, du moins si nous attachons au mot liquide le sens physique dans lequel on l’entend communément, et par lequel on désigne, par exemple, l'état au- quel une basse température et une forte compression aménent la plupart des fluides élastiques. Si M. Poisson n’entend par liquide que cet état des fluides dans lequel la force élastique est disparu, ce n’est plus alors qu'une définition mathématique qui est bonne tant qu’on ne cherche pas a se representer l'état physique du fluide. Toutefois observons que ce n’est pas ainsi qu’on définit les liquides; parceque 1’état liquide suppose non seulement |’absence de force élastique, mais de plus une attraction moléculaire plus ou moins grande entre les particules du fluide, attraction qu’il nous est impossible d’admettre ici.” — Bib. Univ., Nov. 1835. § Phil. Trans., 1822, p. 89. Abstracts, ii. 160. M. Biot appears to give the credit of this remark to M. Poisson; Comptes Rendus, vi. 395. || See on this subject M. Biot’s Memoirs; Comptes Rendus, viii. 91 ; ix. 174; Lambert’sW orks; Lubbock on Heatand Vapours, 1840; also Poisson, Supplément Gla Théorie de la Chaleur, note D, where the author investigates the equilibrium of the atmosphere under certain conditions, but ends with these words: “il ne s’agit dans cette note, que d’un simple exemple de calcul, et vraisemblablement, les hypothéses que nous avons faites pour le faciliter ne sont pas conformes a la nature.” 78 REPORT—1840. though for convenience it is distinguished from the direct. solar heat measured by an actinometer; secondly, the proper low temperature of the higher atmosphere which is communicated to the earth by radiation through the inferior strata. M. Pois- son contents himself with supposing that these two causes neu- tralize one another, or that the latter rather preponderates*, for which he assigns, I think, no sufficient reason ; on the con- trary, from what we have just stated (110.) of the action of the atmosphere, which lets more heat enter than can directly escape, we conceive that the heating effect of the atmosphere is essen- tially positive. . M. Poisson having thus estimated the direct solar effect on the climate of Paris at 24° cent., and the atmospheric in- fluence as nothing relatively to the existing temperature, assigns the temperature which remains, namely, 11°, the actual mean temperature of Paris, diminished by 24°, or — 13° (=8°6 Fahr.) for the heat of space, or the temperature which our globe would take were the sun permanently extinguished. 113. This result must certainly be considered as a very start- ling and improbable one. That the temperature which our globe would take did the sun not heat at all should be actually higher than the mean temperature of many points of its surface exposed to the solar rays during a great part of the year, and nearly 80° of Fahr. above a degree of natural cold actually observedy, is a paradox to which M. Arago drew attention, and which M. Poisson we think did not succeed in rendering plausible{. Fou- rier was distinctly of opinion that the temperature of space must be lower than the mean of any point of the earth’s surface, though he admits that local causes might produce a temporary depression §. The only explanation, indeed, which it can admit of, is that to which M. de la Rive has shown that Poisson’s rea- soning necessarily leads, viz. that the atmosphere is an inde- pendent source of heat|| (or cold, which is the same thing), a conclusion nowhere distinctly admitted by the author. Now this conclusion surely will be very reluctantly adopted, seeing that, even supposing the direct solar influence could be success- fully estimated, the remaining temperature must be derived from (what is called) the heat of space and the heat of the atmosphere. Experiments are, I apprehend, totally wanting which can se- * «Ta partie (namely, of the heat not directly received from the sun by any part of the earth’s surface) provenant de l’atmosphére ne nous est pas connue ; nous pouvons seulement présumer qu’elle est négative.’’— Théorie, p. 520. t Viz.—70° Fahr., by Captain Back. + Comptes Rendus (Paris), i nN. OV. § Mem. de l'Institut, vii. 582. || Bib. Univ., Dec. 1835. SUPPLEMENTARY REPORT ON METEOROLOGY. 79 parate these two united effects ; their relation and absolute in- tensities are therefore, we presume, yet unknown; nor can we understand how it is possible that the higher strata of the at- mosphere can remain permanently colder than the strata be- neath and the sky abeve them, without admitting a paradox of the same kind with a mechanical perpetual motion. 114. Iam aware that M. Pouillet, in his memoir so often cited, has been led to the same conclusion with M. Poisson respecting the low temperature of the aerial coating of the globe, and has actually computed the depression of temperature which might exist in various hypothetical cases. Until, however, M. Pouillet can exhibit an experiment in which so paradoxical a result is actually attained, I am inclined to think that we must consider it as at variance with the fundamental laws of heat as at present received. M. Pouillet has made many ingenious experiments with his instrument designed to measure nocturnal radiation ; and (since the cooling effect of the sky may always be assimi- lated to that of a hollow sphere having a determinate tempera- ture) he has, I believe for the first time, endeavoured to translate into numerical language the indications of his instrument by actually exposing it to the radiating action of surfaces of low temperature, which would have the same effect, whatever be their distance, and that effect being known in thermumetric degrees on his instrument, the eguivadent temperature of the vault of heaven, or what he calls zenithal temperature, becomes known too. All this is very ingenious and clear, and such determina- tions of zenithal temperatures will certainly one day be of great value. But the difficulty is to separate this temperature into that due to the atmosphere, and that due to the temperature of space. As already stated, we are not satisfied that such a sepa- ration has been, or at present can be effected; and the great variations of the assigned temperatures of space strengthen this doubt; for whilst Fourier and Swanberg make it — 40° c.*, Valz, — 45°+, Poisson makes it 13°f, and Pouillet between — 115° and — 175°§. 115. Fourier was the first who distinctly introduced the idea of the proper temperature of space, as well as the first who endea~ voured to assign to it avalue. Our ideas about an absolute zero * See last Report, p. 203, and Fourier, Mém. de l'Institut, vii. p. 598. The grounds on which Fourier’s estimate is made, nowhere exactly appear; Her- schel considers his published statements unsatisfactory (Geol. Trans. III. 297); yet it appears that M. Fourier himself was strongly persuaded of the truth of his estimate, which he thought was not erroneous to the amount of 8° or 10° cent. (Arago’s Eloge de Fourier, p. 55.) + Mahlmann, p. 14, note. t Théorie, p. 520. § Mémoire sur la Chaleur Solaire, p. 38. 80 REPORT—1840. of temperature, far from getting clearer, are perhaps now more unfixed than ever; and what would be the result of a condition of which we can form no very definite physical conception (a body placed in an envelope deprived of heat), it is perhaps too bold to — conjecture. But that the planetary spaces are not exactly in this condition, is not improbable. A body (be it a thermometer ora planet) placed in space may take a temperature, by contact, from a fluid by which it is surrounded, or by radiation from distant stars (being shaded from the sun) ; the latter, we under- stand to be the meaning usually assigned by philosophers to the term Temperature of Space*. This influence may change from age to age, and be variable in different regions of the globe, de- pending on their exposure. M. Poisson supposes that the in- crease of temperature with depth in the earth indicates the effect of an at-one-period-more-intense stellar radiation, and con- sequently that it does not necessarily extend beneath a depth which the epoch of the oscillations of external influence would determine. This is no doubt perfectly unanswerable, as a mat- ter of bare possibility; but it seems hardly worth maintaining an opinion which a million of years will scarcely show to be feasible or the reverset. 116. We have formerly stated {, that Fourier had arrived at the conclusion that the flux of heat from the interior to the surface of the globe did not raise the temperature of the latter above sith of a centigrade degree§, or would melt annually a stratum of ice =3,th of an English inch in thickness ; and in this estimate Poisson nearly coincides ||. The influence of internal heat is quite irrespective of any theory as to the state of the nucleus, and depends only on the rate of increase as we descend, a cir- cumstance which M. de la Rive seems to have overlooked in urging his objections against Poisson’s theory. We proceed to state some important additions which have been made to our knowledge of Facts respecting the thermometric condition of the accessible part of the earth’s crust. * See an interesting notice by Sir J. F. W. Herschel, read to the Royal Astronomical Society, 10 Jan. 1840; Atheneum, Feb. 15; where, as well as in a paper in the third volume of the Geological Transactions, New Series, on Astronomical Causes affecting Geological Theories, are some important sug- gestions on these intricate subjects. + On the subject of the thermometric state of the globe, seea popular article by M. Arago (Annuaire, 1834), and the Eloge of Fourier, by the same author. In the Annales de Chimie, a few years since, Libri has given some results as to the rate of cooling, and the contraction of the earth’s crust, within historic times, chiefly with a view to the supposed explanation which it affords of certain geological phenomena. ¢~ Last Report, p. 221. § Mém. de lV Institut, vii. 590. || Théorie, &c., p. 424. SUPPLEMENTARY REPORT ON METEOROLOGY. 81 117. We have no reason to admit any sensible change in the mean temperature of the superficial part of the globe; at least we are rather disposed to attribute the manifest elevation of temperature observed during twenty years, in the observations in the caverns under the Observatory at Paris, to some permanent alteration in the instrument than to a change of temperature of the earth, a point which we hope the French astronomers will take pains to ascertain. The observations from 1817 to 1835 being divided into four series, give the following results :— FI+7S0 11°°801 11°°857 E950" 118. The mean of 352 observations is 11°834 ; the mean tem- perature of the air at Paris is 10°822+; the difference is to be attributed to the increase of terrestrial heat for 28 metres of descent. 119. Observations on borings, and overflowing or Artesian wells, have been perhaps more unexceptionable of late years than at any former period. We shall give such indications as to record the chief facts observed. Amongst the best obser- vations are those made by MM. De la Rive and Marcet in a boring near Geneva}, under the most unexceptionable circum- stances, which agree extremely well in indicating a uniform increase of heat at the rate of 1° cent. for 32°55 metres of de- scent, or 59 feet for 1° Fahr. The whole depth was 255 metres. 120. A list of Artesian wells and their temperatures has been given by M. Arago, in the Annuaire for 1835; and by Pois- son, on the same authority, in his Theory of Heat§; whence he has deduced: (from fifteen Artesian wells in France, all above 20 metres deep) an increase of 1° cent. for 25°46 metres of descent (46 feet for 1° Fahr.). There appears in these, as well as the Geneva and Paris observations, a remarkable coincidence between the superficial ground-temperature and the observed air-temperature 121. From the comparison of a number of observations, M. Kupffer J deduces an increase of 25°37 metres for 1° Reaumur, or 20°30 m. for 1° cent., or 37 feet for 1° Fahr. 122. A well at Magdeburg gives 1° Reaumur for 100 feet, or 44 feet for 1° Fahr.**, according to Professor Magnus, the inventor of an improved thermometer for such observations. * Poisson, Théorie de la Chaleur, p. 414. + Ibid, p. 467. t Mém. dela Soc. de Phys. de Généve, tom. vi. § P. 420. || It is by no means necessary to infer, however, that this is a general fact. Prof. Reich’s observations, for example, at Freiberg, indicate an excess of 1° c. in the earth-temperature above the air-temperature. Beob. iiber die Temp. des Gesteins, &c., p. 134. §| Poggendorff, xxxii. 284. ** Thbid., xl. 189. See also xxxviii. 593. VOL. Ix. 1840. G 82 REPORT—1840. 123. A very deep experimental bore has been sunk at La Grenelle, near Paris. The latest report* (Aug. 1839) gives a temperature of 27°°5 cent. at a depth of 281 metres, which would infer an increase of about 1° cent. for 164 metres (the su- perficial temperature being under 11°), a result Hardly probablet ; and as the depth of the bore then was between 400 and 500 metres, either the depth of observation has been misstated, or the temperature was raised by water flowing from the bottom. 124. The following are the depths of the most remarkable Artesian wells at present known {:— stentie wisi rencnh feet. La Grenelle, Paris (June 1839) . . . . . . 143671 Neu Salzwerk, near Minden (Sept. 1839) . . . 1434°8 Temperature of brine, 18°°5 R. Nowe Brzesko, Poland (1838) . . . . . ~- 1403°8 Cessingen, Luxembourg (April 1839) . . . . 1646°5§ 125. Perhaps the most interesting, and certainly the most singular observations, on subterranean temperature, are those on the frozen soil of Siberia. At Jakouzk, in lat. 62°, where the mean temperature is —6° Reaum. =18°5 Fahr. (accompanied with such a rigour of climate, that mercury has been known to remain frozen for three consecutive months ||), the heat of summer thaws the soil to an extreme depth of only three feet]. To search for a permanent spring is a matter of great difficulty. A well has been dug to the depth of nearly 400 English feet, with the following most remarkable results as to the tempera- ture of the ground** :— Surface . 9. 2 . . — 6% Reaumur. 77 English feet . . .—5°5 119 cr) . . . oo 4 ‘0 382 ne oh og eee ON5 * Comptes Rendus (Paris), ix. 218. + This result is altogether at variance with that formerly published (Comptes Rendus, vi. 505), where it appears that at a depth of 400 metres the tem- perature was 23°-5 c., giving an increase of 1°. for 31°5 metres, in which also some other springs near Paris very nearly coincide. A still later observation confirms this remark. On the 18th August, 1840, MM. Arago and Walferdin obtained a temperature of 26° 43 c. at 505 metres, giving 32°3 metres for 1° c. (Comptes Rendus, 2 Nov., 1840.) { Poggendorff, xlviii. 382. Notices of some other Artesian wells, Pogg., xxix. 8362. For an a¢count of two Artesian brine springs at Kissengen, see my paper in Jameson’s Journal, April 1839. § It has lately been stated, that the observations of temperature in this Ar- tesian well, at the depths of 180, 230, 280, and 337 metres, give a coincident result of 1°c. for 13 metres of descent, or more than twice as rapid an increase as that usually observed. (L’Jnstitut, 1840, No. 340.) || Erman, Comptes Rendus (Paris), vi. 502. q Bischoff, Warmelehre, p. 137. ** Erman, wé sup. See also Von Baer, in Brit. Assoc., Eighth Rep., Sect. p.96. SUPPLEMENTARY REPORT ON METEOROLOGY. 83 From which it appears that we have a progressive increase of temperature in the frozen soil, which, at a depth of about 400 feet, will give a temperature just freezing. The augmentation would appear to be more rapid than usual, or 1° R. for 60 or 70 English feet. ° ; 126. Of observations in mines we have a most important and extensive series by Professor Reich, of Freiberg*, made under the most favourable circumstances, and with every assurance of their accuracy. They extend to a depth of above 900 feet, and the result of the combination of the whole is an increase of 1° cent. for 41°84 metres, or 1° Fahr. for 76 English feet, with a probable error of only 1-37th partf. 127. Professor Phillips found, in the Monkwearmouth coal- pit, an increase of 25° Fahr. for 1484 feet of descent, or 1° Fahr. for 59°36 English feett. The same gentleman has given valuable instructions for conducting such observations §. 128. Mr. Fox gives 1° Fahr. for 48 or 50 feet as the results of his experiments in Cornwall||._ Mr. Henwood agrees with Mr. Fox in finding a difference in the progression of heat in slate (killas) and granite, and gives the following summary of his experiments J :— 95 observations in slate 1°F,. for 39 feet. 39 a, granite es 41°4 This difference, Mr. Fox thinks, is probably attributable to the action of the mechanical structure of the rocks, in admit- ting superficial water**. * Beobachtungen iiber die Temperatur des Gesteins in verschiedenen Tiefen in den Gruben des Stichsischen Erzgebirges in den Jahren 1830 bis 1832, von F. Reich. 8vo. Freiberg, 1834. t+ P. 181. { Phil. Mag., Third Series, v. 451. § Brit. Assoc., Sixth Rep., p. 291. || Ibid., Seventh Rep., p. 136, &c. §] Ibid., Seventh Rep., Sections, p- 36. ** It will be seen that these experiments have no analogy in their objects with those made at Edinburgh on the influence of the material of the strata > tm the admission of solar beat, as Dove seems to suppose (Repertorium, . 307). A most important question, connected with earth-temperature, yet remains tobe decided. M. Kupffer maintains (see First Report, p. 224), that the super- ficial temperature of the earth exceeds that of the air in high latitudes, and falls short of it between the tropics (as was long ago asserted by Von Buch and others), and he has described Isogeothermal lines to express this fact. Bischoff maintains the contrary (Wdrmelehre, p- 38, &c.), declaring that Kupffer’s lines coincide with those of Humboldt (Isothermal), and that the warmth of springs in high latitudes arises solely from the depth at which they rise (p. 53), and he quotes the observations made by Boussingault, one foot below the surface (where he finds the temperature constant in tropical regions, and equal to the mean air-temperature of the year, dnn. de Chimie, liii, 225), in support of the assertion, that at the equator no difference of air- and earth-temperature exists, G 2 84 REPORT—1840. 129. Most intimately connected with the subject of subter- ranean temperature is that of the temperature of springs, which connects itself so remarkably with chemical, geological, and meteorological considerations. It is impossible not to adopt the idea, that the temperature of spring-water depends on the depth whence it takes its origin, since we now know, beyond any doubt, that up to a certain point at least, the heat of the strata increases as we descend; nor is there the slightest reason to suppose that this progression undergoes any considerable variation down to the (comparatively) moderate depth at which water would boil, however much we may feel the necessity of caution in inferring the actual condition of the earth’s nucleus. The subject is one of so much extent, that we must refer gene- rally to the works which specifically treat of it, amongst which that of Prof. Bischoff, of Bonn*, is the most important in our present point of view. According to him, the temperature of a spring is an index simply of the thermal condition of the stratum whence it takes its origin, or at least derives its chief heat. 130. A very ingenious application of these principles has been made by Prof. Kupffer, and he has illustrated them by an ap- plication to observations of the temperature of two springs at slightly different elevations, near Edinburgh, made at differ- ent seasons of the yeart. By observing the annual range of temperature of the spring, its depth is known by Fourier’s formula, the conductivity of the soil being assumed from Leslie’s experiments. The retardation of epochs is also an index of the depth. Now the actual difference of level of the points of exit of the two springs being given, the difference of temperature due to height above the sea is known. The actual Very contrary results on the latter point, derived from springs, appear in M. Arago’s report on a recent French expedition, under command of Capt. Du- Petit-Thouars (Annuaire, 1840, p. 296), from which the ground would seem to be sometimes 4° cent. colder than the air.— Nov. 1840. * Die Warmelehre des Innern unsers Erdkérpers, 8vo. Leipzig, 1837. Some part of this work has been translated in the Edinburgh Philosophical Journal. It consists of four parts, containing 27 chapters, and is full of re- search and important information. + These observations, published anonymously in Prof. Jameson’s Journal in 1828, were made by me. I have only lately found that they have been sub- jected to an ingenious and searching analysis, first by Kamtz (Météorologie, li. 190) afterwards by Kupffer (Poggendorff’s Annalen, xxxii. 280), and made to yield results which, in making them, I could not have contemplated. This is one instance out of many, for the encouragement of young observers, showing that observations conducted on system, carefully and perseveringly made, and complete so far as they go, may afterwards prove of unexpected importance. SUPPLEMENTARY REPORT ON METEOROLOGY. 85 difference of observed temperatures is not, however, the same, because the one spring rose from a greater depth than the other. The variation due to this cause then becomes apparent ; and the difference of depth from which they rise being known, the rate of increase is found by M. Kupffer to be 1° Fahr. for 41 English feet ; a process which must be admitted, at all events, to be extremely ingenious. He has treated some of Wahlen- berg’s observations in a similar way*. 131. On the subject of hot-springs, or those which have a temperature notably higher than that of the air, (though, as Bischoff has well remarked, there is an insensible gradation,) we cannot now enter; and this is the less to be regretted, as Dr. Daubeny has already presented an ample report to the British Association on the subjectt. M. Arago has published some valuable remarks on the same subject, especially on the curious phenomena of the springs of Aix in Provence{. With a view to direct the attention of naturalists to the secular and annual changes of temperature in hot-springs, I have made some very detailed investigations on this subject, which I have published, as far as relates to those in the Pyrenees§. The central heat theory would require these to be insensible, as indeed they appear to be in the best known instances. IIl.—AtTmosPHERic PREssuRE. A. Barometers||. 132. The standard barometer of the Royal Society of London has two tubes, one of flint, the other of crown glass, adapted to a common cistern, with a view, it is believed, of ascertaining whether any change in the capillary action occurs, depending on the nature of the tube. The scale, according to Dr. Prout’s ingenious construction, is itself moveable, its zero coinciding with a fine agate point, which terminates it, and which may be brought into the nicest contact with the mercurial surface in * In Prof. Kimtz’s Lehrbuch der Meteorologie, ii. 186, &c., is much valu- able information on the subject of springs; also in Dove’s Repertorium, ili. 310, ¢ British Association, Sixth Report, pp. 1—95. { Annuaire du Bureau des Longitudes, 1836, p. 265 ; see also M. Valz’s com- munication, Comptes Rendus, vol. x. § Phil. Trans. 1836. On the subject of hot springs, Osaun’s work in 2 vols. 8vo. (Europa’s Heilquellen, Berlin, 1829), may be consulted in German, Ali- bert’s in French, and Gairdner’s in English ; but the temperature observations seldom afford more than a rude approximation to the truth. || See last Report, p. 225. Mahlmann, p. 77. 86 REPORT—1840. the cistern; the vernier has a proper motion upon the scale, in order to read off the height*. 133. M. Kupffer has proposed a stationary barometer, in which a siphon-tube stands alone, and quite detached from a graduated column, along which a micrometer travels, and reads off the differences of elevation of the two extremities of the mercuryt.. M. Breithaupt has also proposed a plan somewhat similar. It may very safely be affirmed, that the mechanical act of reading off the length of the column is already accom- plished with more accuracy than the otherwise imperfect nature of the instrument requires. 134. Mr. Daniell recommends Newman’s portable barome- ters, with correction for the capacity of the cistern, and such have been supplied to the Antarctic expedition§. Mr. Newman has adapted an ingenious cast-iron cistern to his instrument, which consists of two parts, one of which contains the super- fluous mercury during carriage, the other being always full |]. 135. M. Bunten,of Paris, a most ingenious and excellent artist, has made a great improvement on Gay-Lussac’s portable siphon- barometer, in which a chamber is left in the principal tube, in which any air which may have accidentally left the bend of the siphon is inevitably lodged, and may be expelled at leisure without injury to the vacuum. M. Bunten constructs these instruments himself with peculiar skill, and provides them with excellent portable wooden cases. The same artist has recently contrived a very ingenious, elegant, and simple cistern-baro- meter, with the graduation on the glass, and which can be made at so moderate a price as ought to supersede the rude instru- ments commonly purchased at twice the cost]. 136. Greiner, of Berlin, a most excellent manufacturer of meteorological instruments of the most delicate kind, has con- structed a siphon-barometer, with the material advantage of confining the superfluous mercury (which by frequent shaking becomes oxidated), and yet in such a way, that the expansion by heat cannot possibly endanger the instrument**. His baro- meter, more cumbrous and more expensive than Bunten’s, is well adapted for nice observations, to be pursued for some time at a fixed station, whither the instrument has first to be con- veyed. ‘ * See Mr. Baily’s description, Phil. Mag., Third Series, xii. 204. + Poggendorff, xxvi. 446. $ Ibid., xxxiv. 30. § Royal Society, Instructions, p. 56. {| Brit. Assoc., 3rd Report, p. 417. 4 The defect of this instrument in its present form, is the difficulty of access of the air to the cistern. ** There is a descriptive pamphlet published at Berlin in 1835, SUPPLEMENTARY REPORT ON METEOROLOGY. 87 137. Mr. Harris, of Plymouth, has had the merit of exe- cuting, for the first time, perhaps, with accuracy, a wheel, or circular index-barometer, a matter of very great importance as well as difficulty, because it enables unlearned persons to read off the height without the aid of a vernier; and in fact to this we owe the most valuable and unique series of hourly barome- trical observations, to which we shall presently refer*. 138. Prof. Stevelly, of Belfast, has proposed a self-registering barometer, on the principle of causing a moveable cistern con- taining mercury to rise or fall by the weight of the fluid dis- placed from a fixed barometer tube immersed in it. The tube here may evidently be opaque, as of iron. 139. A water-barometer has been constructed and observed in the Royal Society’s Apartments (London). Some elaborate comparisons of its indications with standard instruments will be found in Mr. Hudson’s paper f. 140. On the still-agitated subject of capillarity, as affecting barometric readings, I refer to some recent essays of Bessel, Dulong, and Bohnenberger §. 141. Of barometers acting on principles different from that of a simple column of mercury, the so-called (not very appropriately) differential barometer of Auguste, as improved by Kopp], is the most ingenious. Its principle, so far as it can be concisely stated without a figure, is this: if air of any density whatever be compressed into a given fraction, say $ths of its natural bulk, it will sustain a pressure equal to the atmospheric pressure, and a certain fraction more, depending on the fraction denoting the compression (in the supposed case its elasticity would be balanced by the atmospheric pressure, and ird more). If, then, this fraction of excess of pressure is known by experiment, the whole pressure is inferred from a knowledge of the construction of the instrument. Thus, instead of a column of 30 inches of mercury being required, one of 15, 10, or any other number may be used and multiplied by the constant factor. In Kopp’s instrument, the experiment is very simply and neatly made. A glass chamber communicates freely with a vertical tube, which is open to the air until mercury forced in from beneath cuts off the communication: the pressure by which the mercury is in- troduced being continued, the air in the chamber is condensed, and the mercury: rises in the vertical tube, so that its pressure, together with that of the atmosphere, may balance the elas- ticity of the air. The compression is continued until the air is * British Association, Third Report, p. 414. + Transactions of the Royal Irish Academy, 1836. { Phil. Trans. 1832. § Poggendorff, xxvi. 451. || Poggendorff, xl. 62. 88 REPORT— 1840. observed to be condensed to a known fraction of its bulk, when the length of the column of mercury is also a known fraction of the total barometric column. I brought one of these instruments to this country two years ago, but I have not yet made trial of it. 142. Mr. Cooper has proposed a barometer acting by the elasticity of the air in a floating vessel regulated by weights, which constantly immerse it to the same depth*. The author considers it capable of showing a difference of elevation of three or four feet. It is intended that the apparatus should in every case be employed at a constant temperature of 75°, to which it is artificially brought: I conceive that this process is attended with inevitable disadvantages. 143. SirJohn Robison has proposed to use tubes or long phials containing air, immersed in water at the top of a hill, instead of an air barometer or sympiezometer. The portion which be- comes filled with water, when re-examined, would indicate the previous rarefaction of the airf. In this and every similar case the temperature of the included air is a matter of great uncer- tainty, and prevents the possibility (as contemplated) of trust- ing such instruments to inexperienced assistants. B. Mean Height of the Barometer. 144. Several considerations would lead us to the inference, that the mean pressure of the atmosphere at the level of the sea should vary with the latitude; but it is to experiment alone that we can look for any indication of a law. Humboldt ap- pears first to have remarked, that the height of the barometer is lower at the equator than in temperate latitudest; and, excepting this fact, little more has been known until the late excellent researches of Schouw§, though the partial observa- tions of occasional navigators indicate this fact, as well as avery considerable depression of the barometer towards the pole|]. 145. M. Schouw’s statement is the following :— Mean pressure at Level Sea, in French Lines. Lat. 0° to 15° high temp. with a rainy season 337—7 >» 15 — 30 very dry; rainsrarely . . . 338—9 9» o0.— 45 temperate. +2. are ee ee ee » 45 — 65 coldandrainy. . .. . . 33753 * Philosophical Transactions, 1839, p. 425. + British Association, Eighth Report, Sections, p. 37. Brunner has de- scribed an air-barometer, Poggendorff, xxxiv. 30. t Tableau Physique, p. 89, quoted by Kamtz. § Annales de Chimie, tome liii. (1833). See also Poggendorff, xxvi. 395. || See the authorities cited in Humboldt’s Note to Arago, Comptes Rendus, ii.570. Some valuable comparisons of barometers at different northern observa- tories are to be found in a late number of the Comptes Rendus (1840. 2me Semestre). SUPPLEMENTARY REPORT ON METEOROLOGY. 89 The maximum appears then to be about the 45th degree, and it diminishes on either hand. 146. The equatorial depression, and the maximum near the 40th degree of latitude, is indicated not only by the fived annual observations given in Schouw’s paper, but also by progressive observations made on board ship by Capt. Beechey*, Sir J. Herschel}, Sir E. Ryant, and Mr. MacHardy+; the latter are important, as showing that the same distribution prevails in the southern hemisphere. Mr. MacHardy’s observations in southern latitudes give Between 0° and 5°S. . . . 29°821 Eng. inches. SER he ou Yaya eh OROM # ines HO a ay Mey OED » pres Meme oe? 30°085 ts 147. Prof. Poggendorff, of Berlin, has very justly remarked ft, that the question of the actual pressure of the air at any point of the earth’s surface, supposes that that pressure is measured upon a constant scale of force ; but owing to the variation of the force of gravity, the weight of a given length of the mercurial column is not constant, and the effect of attending to this correction is to exaggerate the depression at the equator, and diminish some- what (but not annihilate) that in the arctic regions. Such a corrected table, deduced from Schouw’s, will be found in the Comptes Rendus and in Poggendorff’s Journal. The propriety of the correction will be evident (as M. Poggendorff observes), if we recollect that the elasticity of air, and the boiling point of water, may be used, as well as the counterpoise of mercury, for indicating the atmospheric pressure. 148. The height of the barometer, at least in temperate regions, varies with the season of the year. At Paris and Strasburg it appears to attain one maximum in summer and another in winter. M. Kamtz attributes the summer maximum, with great probability, to the pressure of vapour§: when this is allowed for, we have amaximum in February and a minimum in August or September. The prevalence of particular winds (as we shall see) causes temporary elevations of the barometer in particular parts of the earth’s surface, which may lead, and have led, to very erroneous conclusions. _ 149. There seems, however, on the whole, no reason to doubt the existence of such atmospheric valleys as were adverted to in the former report||. * Comptes Rendus, ii. 572. + Second Report of the Meteorological Committee of the South African Institution, p. 2 (for which I am indebted to Sir J. Herschel). t Annalen der Physik, xxxvii. 468. § Lehrbuch, ii. 297. || P. 228. 90 REPORT—1840. 150. There is no instrumental result to be received at all times with more doubt than the absolute height of the barometer. I have had occasion to compare many which have the character of being standard instruments, and have found the most serious inconsistencies. There are few points at which the mean press- ure of the atmosphere can be said to be accurately known. Even at Paris there is some little doubt* ; when reduced to the level of the sea, itappears to be 760°85 millimetres}. From seventeen years of very careful observations at Marseilles, it is 761°61 at 0°, and at the level of the seat, clearly indicating that Paris lies considerably to the N. of the maximum pressure zone. It may be doubted whether we possess in this country any satisfactory evidence of the mean height of the barometer at the level of the sea$. C. Barometric Oscillations ||. 151. The investigation, by Mr. Snow Harris, of the diurnal atmospheric tide by means of hourly observations, continued at Plymouth night and day for three years ], has led to a very satisfactory determination both of the epoch and amount. Ac- cording to him, the maxima occur at 93 4.m., and at 10 p.m., the minima at 445 a.m., and 31" p.m.; and the measures ap- pear to be the following (approximately) :— Rise from 4 a.m. to 10a.M. . . *014 inch al), 20 4.m. to "Ss Pom. >.” oS! "OL ger Rise’ 5, 3°P.M.tolO p.m. . . “O21 ';; Fall ’,, -10' p.m. to 4am...) . *O18~',, The maximum oscillation here appears to be between 3 P.M. and 10 p.M., and amounts to 0°53 millimetres. My formula** gives 0°60. Mr. Harris deduces 29°800 for the mean pressure 60 feet above the level of the sea, which agrees nearly with the observations at Somerset House; but there is some material discrepancy in the observations of mean height for different years. * M. Bouvard gives 755°99 mm. reduced to 0° c. from eleven years’ obser- vation at Paris; M. Arago, 755°43 mm. from nine years’ observation. + Arago. t Kindly communicated to me by M. Valz, of Marseilles. § The Royal Society Observations since Nov. 1837 (see Phil. Mag., xii. 204), may one day afford this, but the period is as yet rather too short. | Last Report, p. 229. _Mahlmann, p. 89. 4 The results were partly communicated to the British Association in 1839 (see Atheneum, 14th Sept.). The following results, which are corrected for — temperature and embrace three years, were communicated to me by Mr. Harris himself. The agreement of the three years is very satistactory, so far as the form of the curves is concerned. See also British Association, Eighth Report, . 22. ** Edinburgh Transactions, vol. xii. SUPPLEMENTARY REPORT ON METEOROLOGY. 91 152. Mr. Caldecott, astronomer to the Rajah of Travancore, has obligingly communicated to me the results of his observa- tions in 80° 30! N. lat., where he finds the oscillation from 10 a.m. to 4 p.m. to be ‘109 English inches = 2°77 millimetres, whilst my formula gives 2°57. There appears to be some anomaly at the Cape of Good Hope, if the reductions with which Sir John Herschel has furnished me represent correctly the series of observations made at the Royal Observatory there. From 58 months’ observations (lat. 33° 56’ S.), the oscillation is “025 mm. = 0°64 mm. The formula would give 1:42 mm., or more than twice as much; a difference altogether improbable, or else indicating some remarkable local anomaly. 153. Colonel Sykes* finds the maximum atmospheric tide in the East Indies (mean lat. 183°, mean elevation 1800 feet), to be between 9-10 a.m. and 4-5 p.M., and to amount to ‘107 inch =2-72mm. by four years’ observations. The formula gives 228mm. Colonel Sykes finds the hours to be unmodified by elevation, and to be the same as in Europe and America. He has also shown such enormous irregularities in the results from different parts of India, and even in the same place at different times, as do not so much militate against any particular for- mula, as they show the impossibility of any one formula embracing such discordant conclusionst. Colonel Sykes has shown that the supposed interruption of the atmospheric tide during the prevalence of the monsoon has no existencef. _ 154. Prof. Kamtz§ has made some interesting observations on the variation of the atmospheric tide with height|| in Switzer- land, on the summits of the Faulhorn and Rigi, compared with Zurich and Geneva. The hours are nearly the same in all Cases, 4 a.m., 10 a.M., 3 P.M., 9 P.M. rd French Lines. The mean oscillation at Zurich and Geneva . 0°398 Panthorn o.oo OYE ri Dy) ~ * Philosophical Transactions, 1835. t Ibid., p. 176. __{ An account has been published (Proceedings of the Royal Society, May 2ist, 1840), since this report was written, of valuable Observations on the Pperometer, by Capt. Thomas, at Alten, in Finn-marken, in lat. 70°; from which it clearly appears that the barometric oscillation is there negative, as my formula would indicate that it ought to be. I am bound to apply to the “Report” on Capt. Thomas’s Observations published as above, the remark which I have made upon Colonel Sykes’s paper, in the text, viz. that it is ' searcely philosophical to expect that any formula should coincide more nearly With observations, than one year’s observations do with another. __§ Poggendorff, xxvii. 345. See also Gautier on the Annual and Diurnal Variations of the Atmospheric Tide. Bibi. Univ., N. S., xxiv. 124, | See former Report, p. 232, and my paper in Edinburgh Transactions, vol. xii. 92 REPORT—1840. Another series gives— Mean oscillation at Zurich . «. . . « « O0°286 os BS HO PRs a eS The two results agree very closely in assigning a value of the oscillation depending on the absolute pressure. M. Kamtz thinks that the diminution with height is as the diminished pressure, and may be expressed by 335th of the change of pressure. Thus, at the equator, the oscillation (according to him) would cease at a height where the barometer falls to 115 lines, and afterwards, no doubt, would become negative, as I have formerly shown. ‘The observations cited by Col. Sykes* confirm the general principle. 155. The cause of the diminution of the diurnal tide with height is no doubt this :—that the great vertical depth of air which exists between Geneva and the Great St. Bernard, for example, becoming heated by the action of the sun commencing at the earth’s surface, a portion of air is raised above the upper station in the afternoon, which in the morning was below it ; consequently this produces a diurnal tide in the higher regions, which has its maximum after the hottest part of the day, and which therefore counteracts the true diurnal tide. 156. On the subject of the lunar influence on the barometer, we may refer, in the first place, to the popular article by M. Arago, in the Annuaire for 1833+; who gives the results of Flaugergues, mentioned in our last report{, which give a de- cided maximum at the last quarter, with which the observations of MM. Boussingault and Rivero, at Santa Fé de Bogota, agree. According to a late and complete reduction of the Paris observations by M. Eugene Bouvard§, we have a first maximum on the 8th day of the moon, and a second or prin- cipal one on the 22nd day; the principal minimum on the 13th, and a second on the 27th day. Here, therefore, we have, as above, a decided maximum about the last quarter. The oscillation is 1*°78mm. Mr. Snow Harris has arrived at the same result as respects the principal maximum||, which may probably be considered as established. We shall return to this subject in treating of the fall of rain, and dependence of weather on the lunar phases. D. Barometric Variation with Height]. 157. I will adda few observations on this subject, especially * Phil. Trans. 1835, p. 176. + P. 178. t P. 234. § Correspondance de l’ Observatoire de Bruxelles, tom. viii. || Athenzum, Sept. 14th, 1839. q Last Report, p. 236. Mahlmann, p. 119. $$ eee——es—SsSsS— = SUPPLEMENTARY REPORT ON METEOROLOGY. 93 in correction or addition to those contained in my former report. 158. M. Bessel has given an Essay on the Theory of Baro- metrical Measurements*. 159. The important question of determining levels by obser- vations of distant barometers, is materially affected by the now- admitted difference of mean barometric pressures at different localities ; and it also appears that, unless these observations are steadily continued for considerable periods, they must be liable to serious errors. Thus M. Galle (the assistant astrono- mer at Berlin) has pointed out, in two interesting communica- tions}, that in certain situations enormous errors of barometric measurements arise at certain seasons, which he ascribes to the influence of local winds. It is very plain, that if, from any cause, the monthly variation of mean pressure of which we have already spoken, follow one course at one station and another at a second, the height deduced from any barometric formula will also depend upon the season. This M. Galle has found to be most remarkably the case between Katherinenburg and St. Petersburg. The calculated difference of height varies with the season, having a maximum in summer and minimum in winter; it depends, in fact, on the Difference of Temperature of the two stations. The height is greatest when the difference of tempe- rature is least ; and when the difference of temperature changes its usual sign, the height becomes greatly exaggerated. Thus we have the following analogies :— Diff. Temp. Katherinenburg above Reaum. St. Petersburg, in Toises. from — 2° to 0° 141 0 ae 103 2 4 93 6 7 82 The differences of temperature again depend immediately on the prevailing wind, and therefore on the season. Such an anomaly is not observed between Kasan and Katharinenburg tf. 160. This anomaly is both important as a physical fact and in its consequences. The vast continental regions of Russia sustain aerial columns, which do not make hydrostatic equilibrium with one another. It affords a fresh reason for re-investigating the much-agitated question of the level of the Caspian Sea§, which may now probably be considered as set at rest by the results of * Schumacher’s Astr. Nachr., No. 279. Poggendorff, xxxvi. 187. + Poggendorff, xlviii. 58. 379. { Humboldt, Ehrenberg, and Rose’s Reise, i. 277, quoted by Galle. § See an elaborate paper by Lenz on this subject, Poggendorff, xxvi. 353. 94. REPORT—1840. the last Russian expedition, by whom the space between the sea of Asov (communicating through the Black Sea and Medi- terranean with the ocean), has been accurately levelled, and the depression of the Caspian found to be real, but amounting to only 81:5 English feet *, instead of 334 feet, as formerly sup- posedt+. But what is interesting is, that the barometrical observations made with the utmost care, and at multiplied intermediate stations (one German mile apart), confirm the older results obtained by the same means. The very same kind of anomaly as observed between Katherinenburg and St. Petersburg, occurs here, and even gives to the elevation of the Sea of Asov a negative sign at certain seasons. The Sea of Asov, though further south and lower than the Caspian, has a climate 30° Fahr. colder in the middle of January f. 161. There seems to be very little doubt that the Dead Sea lies also below the level of the ocean. The very discordant, but almost simultaneous results, obtained by different travel- lers§, lead us to admit the fact as probable, and even to con- jecture that the depression may be considerable. 162. M. Kamtz|| has given some very useful results as to variations of computed height depending on the hour of the day, which acts much in the way in which the season of the ear affects barometrical measurements. The maximum cal- culated height occurs at noon, or soon after; the minimum, about 4a.m. The effect is far greater than the atmospheric tide would produce, amounting to 21— 27 toises upon 1100 (the difference of height of the Faulhorn and Zurich, or Geneva), and to 13 upon 700 (Rigi and Zurich). Hence it appears that Ramond’s rule of employing the noon observations for deducing heights is not in this respect exact]. : 163. We do not of course propose to give any results of baro- metrical measurements. ‘The temperature of boiling water is not unfrequently employed, but seldom with sufficient instru- ments. It has several practical difficulties; amongst others, that of obtaining sufficient heat at great elevations, and in ex- posed situations, to cause water to boil. M. Hugi, of Soleure, in his enterprising Alpine excursions**, has used the boiling point of alcohol with good effect. It may seem surprising that this should be tolerably constant, but such I have assured * Poggendorff, 1840, and Edin. Phil. Journal, July 1840. + First Report, p. 239. t See Galle, ut sup. § Edinburgh Philosophical Journal, 1840. || Poggendorff, xxvii. 345, and Dove’s Repertorium, vol. iii. € On the influence of winds on barometrical measurements, see Brandes, Beitrdge, p. 216. ** Naturhistorische Alpenreise. 8vo. Solothurn, 1880. SUPPLEMENTARY REPORT ON METEOROLOGY. 95 myself by experiment to be the fact. Hugi states (what is very conceivable), that the boiling point of water anticipates the barometric indications by some hours; but he states (what is more difficult to understand), that the boiling point of alcohol harmonizes with the latter*. Il].—Huvumipiry+. A. Hygrometers. 164. No new hygrometer has been introduced of late years, so far as I am aware, at least no important novelty, but very considerable progress has been made in the right interpretation of results ft. 165. By far the completest historical treatise which [have seen on hygrometry and hygrometers, is a learned thesis by Suer- man (different from the one already cited), entitled ‘‘ Commen- tatio de definiendd quantitate Vaporis Aquei in Atmospherd,”’ &c.§, which also contains good figures, and many pertinent original criticisms. 166. As hygrometry essentially turns upon a right knowledge of the relations of heat and moisture, we may first observe, that a considerable number of attempts have been made (without new experiments) to express, by some simple formula, the relation between the temperature and pressure of vapour. The only experiments of any consequence that I am acquainted with are those of the Franklin Institute (America), conducted under the superintendence of Prof. Bache||._ They do not much surpass 10 atmospheres, and even there the difference is 6° Fahr. be- tween them and M. Dulong’s results, a difference which does not seem to be satisfactorily accounted for. M. Dulong’s formula represents observations above 1 or 2 atmospheres better than those below ; and there is reason to think that, whether from the mode of conducting the experiments, or some other cause, there is some solution of continuity in the law which expresses the relation of density and pressure somewhere near the point arbi- trarily called the boiling point. * Naturhistorische Alpenreise, p. 16. , + See last Report, p. 239, and Mahlmann, p. 129. t “Jam vero letior campus arridet quo recentiorum experimenta exponenda veniunt, qui, de vaporis natura longe certiores, multa simpliciorem tutioremque — quam przecedentes physici, ingredi potuerunt.”—Suerman, Commentatio, § 45. § 4to. Lugd. Bat. 1831, p.128. For this, too, I was indebted to the late Prof. Moll. || Report on the Explosions of Steam Boilers. Philadelphia, 1836, p. 76. 4] The formula which the American Committee adopt to represent their re- sults is (for Force corresponding to Degrees of Fahrenheit) e = (-00333 ¢ + 1)°. 96 REPORT— 1840. 167. Spasky* has taken the trouble to ascertain whether the constants in Dulong’s formula (viz. the factor of ¢ and the ex- ponent), might not be altered so as to represent the observations better, but he has obtained a very insignificant change. 168. Egent, writing on the same subject, criticises the different formula, and gives one expressing the temperature in a series of successive powers of logarithms of the force or pressure. 169. Biot ¢, Schmeddink §, and Roche ||, have all written on the same subject recently, and proposed new formule. Mr. Russell has proposed to adopt a modification of Dalton’s scale of tem- perature, by which the elasticities may follow an accurately geometrical progression. Mr. Lubbock** has deduced, from theoretical considerations, a formula sufficiently simple, and which represents, with extraordinary fidelity, the observations of the Commission of the Institute; less accurately those of Southern below 212°. 170. I mention these results as generally connected with the subject; the actual range of hygrometric observations requires such a formula to be used as shall best represent the elasticities under 212°. . 171. The formule in use are (1.) that derived from the obser- vations of Dalton and Ure; (2.) that deduced by Kamtz from his own observations ff ; (3.) the table calculated by Ivery’s formula, founded on Ure’s experiments ; it is that given in the second edition of Daniell’s Meteorological Essays, and adopted in the Royal Society’s Instructions for the Antarctic expedition. Of these, Dalton’s has best stood the test of time. Kamtz’s is recommended by Kupffer{{, but is condemned by Egen§§, Lloyd |||], and Apjohn. In the first place, let us turn for a moment to the data of the problem. 172. The dew-point being obtained by the method of Dalton, or that of Daniell, the quantity of vapour in the air, and the ratio of the contained vapour to what might be contained in * Poggendorff, xxx. 351. Instead of e=(1-+ 0°7153 #)°, he finds (1 + 719 ¢)*-9987 for the elastic force, ¢ being in cent. degrees. + Pogg. xxvii. 9. t L’Institut, No. 26, p. 222. Pogg. xxxi. 42. § Pogg. xxvii. 40. || Silliman’s Journal, xxvili. 363. { Proceedings, Royal Society of Edinburgh, vol. i. p. 227. ** On the Heat of Vapours, p. 7. Lond. 1840. ++ M. Kamtz’s first work on the subject was published at Halle in 1826. In the first volume of his Meteorology, p. 289, he has given an account of original experiments on which his formula is founded, which appears to differ very sensibly from the results incommon use. This formula has had its con- stants more lately modified, as appears by M. Kupffer’s citation of it. See below. tt Bulletin de l’ Acad. de St. Petersbourg, tom. vi. No. 22. §§ Pogg. xxvii. 25. || || Proceedings, Royal Irish Academy, 1840. SUPPLEMENTARY REPORT ON METEOROLOGY. 97 air under the circumstances* (which is the true expression for dampness), is at once obtainable from a table which shows the maximum force of vapour for each degree, and the number of grains in one cubic foot of space. But unfortunately the ex- periment is always a troublesome, sometimes an impracticable, and sometimes a fallacious one. Mr. Harcourt} has pointed out various mechanical circumstances which affect the appearance of a film of dew. To reduce a hygrometric observation to an observation simply, and not to an experiment, is the object of the moist-bulb problem, in which the refrigeration of a wetted surface becomes the index of the dryness. The theory is more troublesome, but the observation has every requisite of sim- plicity and consistency f. 173. The moist-bulb problem was especially pointed out as one deserving careful solution in the recommendations of the first meeting of the British Association at York§, and they have been responded to in more than one quarter, so that we may now consider the moist-bulb problem as practically solved. 174. Even at that time the solution had taken a simple and exact form in Germany, and for the labours of Auguste|l, Bohnenberger§ and Kamtz**, the British Association can- not probably claim any merit. The works of the two former are, | am sorry to say, still as unknown to me (by actual in- spection), as when I wrote my former report. 175. Athermometer having a thin film of water surrounding it will take a temperature depending on the following circum- stances :—The air in contact (whether it move quickly or slowly) gives to the film of water, which is converted into vapour suf- ficient in quantity to saturate the space which the air occupies, just enough of heat to vaporize that water, and the reduction of temperature will be accordingly. Thus, if the air (or space) be very dry, it will take up much vapour, but that vapour must have combined with much heat in order to change its state from water, and the temperature of the air in the (now) saturated * When we speak of vapour contained in air, of course we are not to be understood to infer any combination between them. + Phil. Mag., 3rd Series, vii. 409, and British Association, Fifth Report, Sections, p. 54. { This method was the invention of Dr. Hutton, of Edinburgh, which M. Kupffer has erroneously attributed to Auguste (Instructions, &., p.32), and Mr. Prinsep to Leslie (Journal of Asiatic Society of Bengal, 1836, p. 399.). § Original edition, p. 49. These recommendations were drawn up by the author of the present report. || Uber die Fortschritte der Hygrometrie in der neuesten Zeit. Berlin 1830. q In the second volume of the Tubingen Nat. Hist. Society’s Memoirs. ** Lehrbuch der Meteorologie, i. VOL. Ix. 1840. H 98 REPORT -—1840. space is lowered accordingly. Further, it will be more lowered if the air be rare, or the barometer low, because the air yields less heat. Ail these circumstances may be taken into account, and the elasticity of vapour existing in the air may yet be ex- pressed by the following simple formula* :— ae AL cabo 2 es e =e —m(t—?t) B where ¢ and ¢ are the readings of a dry and a wetted ther- mometer ; é the maximum elasticity of vapour corresponding to 7 ; e! ” 2” » to the dew-point ; b the observed height of the barometer ; B a standard barometric pressure (as 30 inches). The concluding factor is usually small, and except at great heights may be neglected. 176. Whene", the elasticity corresponding to the dew-point, is found, the quantity of vapour existing in the atmosphere is known. 177. The chief value of a dew-point instrument is to enable us to determine directly the value of m, which the direct experi- ments on the specific heat of air leave under some uncertainty. 178. Conversely the specific heat of air may be determined from hygrometric observations. This has been done by Dr. Apjohnt. 179. The value of m manifestly depends upon the unit of elas- ticity, and upon the unit of temperature. 180. Dr. Apjohn, of Dublin, whose attention was directed to the subject by the suggestion of the Committee of the Associa- tion, has, in a series of interesting papers, tested the value of m in a variety of circumstances by his own experiments}, and by those of others§. Assuming De la Roche and Berard’s value of the specific heat of air, he finds m, for English inches of mercury, and for Fahrenheit’s degree, to be gy = °01149: a posteriori he has determined it— (1.) from experiments on the dew-point . . . ‘01151 (2.) es on refrigeration in dry air. °01150)| * This formula, employed by Auguste and Bohnenberger, coincides essen- tially with that of Ivory (Phil. Mag. Ix. 80.), who first gave a proper theory of the moistened bulb hygrometer. His value of m is not far from the truth, being ,1, for cent. degrees, or >, for Fahrenheit. + Irish Trans., Phil. Mag., and Brit. Assoc., Sixth Report. See also Suer- man’s Thesis. +Phil. Mag., 8rd Series, vii. 266. 470. § Ibid., vi. 182. || Prof. Lloyd has ingeniously made this set of experiments the means of testing the accuracy of the tables of the force of vapour, and he prefers Dalton and Ure’s calculated by Anderson.— Proceedings, Royal Irish Academy, 1840. SUPPLEMENTARY REPORT ON METEOROLOGY. 99 (3.) from experiments on refrigeration in air once saturated, then warmed. . .. .. . . ‘01140 nearly coincident with one another, and with the theoretical determination. 181. Bohnenberger* had already obtained a value sensibly identical, which probably was not known to Dr. Apjohn at the time he made his experiments ; for English inches and Fahren- heit degrees, he obtained — First, from 56 observations . ... . m=+°0114 Afterwards, from 45, which he preferred . "011398 182, M. Kamtz, in avery valuable paper on the results of his extensive observations in Switzerland, has given his formula in a slightly different form, but which indicates an almost precise coincidence between theory and experiment, both for the case where the thermometer is above freezing and below ; for in the latter case equally the principle holds, only we must allow for the latent heat absorbed in liquefying as well as vaporizing the water. Including the barometric formula, M. Kamtz writes the second term of the formula for the elasticity thus : — 0°001004475 (¢ — #') b, b being the barometric height in French lines, the standard barometric height 336 lines, by which the co-efficient (which is for Reaumur’s scale) has been already divided. 183. The above expression is the theoretical one above 0° R. The theoretical one below O° R. is — 0:0009375 (¢ — #’) b. 184. These two numbers, deduced @ posteriori from the Swiss observations, give ° Faulhorn . . ‘0010026 34 obs. pene OB rae PS oo doasd. 31 Below 0° Rf en . . 000945014 15 33 Zurich . . . *0009995 11 from direct comparison with the dew-point. 185. I have given these numbers, that their coincidence may be perceived. Again, to compare them with Apjohn’s and others, we may take those at the Faulhorn and reduce them to English measures and a mean barometric pressure, when we shall obtain Above 32° Fahr. . . . m=:0118 Below 32° Fahr. . . . m= ‘0112 * Suerman, p. 88. + Poggendorff, xxx. 33. 2 = tw 100 REPORT—1840. 186. M. Kupfier*, though he adopts Kamtz’s table of elastici- ties, after examining the experiments of Gay-Lussac, Bohnen- berger, Auguste, and Erman, finally prefers this value of m, 1h Vt i ae a eG Hi 8 2 almost coincident with that of Bohnenberger and Apjohn. 187. A most elaborate paper has been published by Mr. Prin- sep, of Calcutta, in the Journal of the Asiatic Society of Bengal7, on the wet-bulb problem, in continuation of the ingenious, but rather obscure ones, alluded to in the former report, as having been published in the ‘* Gleanings of Science’’t. Mr. Prinsep states, that the notice taken of his former labours, in the First Report of the British Association, had stimulated him to re- sume the subject, and he has accordingly furnished us with a great many valuable test-experiments, which can nowhere be so well performed as in warm climates. Mr. Prinsep’s ori- ginal memoir will be consulted by those who wish to avail themselves of his valuable researches for the improvement of theory : it is not necessary to dwell upon those points where he seems to us to be less explicit, or historically not quite exact ; and the great point is to be clearly satisfied that we have now-ub- tained a sufficient interpretation of the indications of the moist- ened thermometer. When we find that Mr. Prinsep once more coincides with Dr. Apjohn’s numbers, only hesitating whether to prefer j; to ,', for the value of m, we are prepared to admit that this problem is, practically speaking, completely resolved ; and this being the case, it is scarcely worth while to disentangle the various imperfect steps by which so happy a consummation has been attained, and the hygrometer rendered as commodious and as accurate as the common thermometer§. The leading steps of the generalization are these :—Hutton invented the method; Leslie revived and extended it, giving probably the earliest, though an imperfect theory; Gay-Lussac, by his ex- cellent experiments and reasoning from them, completed the theory, so far as perfectly dry air is concerned; Ivory ex- * Bulletin de ’ Académie des Sciences de St. Petersbourg, vi. No. 22, for which I ani indebted to Major Sabine. + No. 55, July, 1836. t The “ Gleanings in Science’”’ referred to in the original Report of the British Association, had been lent to me by Sir D. Brewster, to whom they had been sent. I afterwards communicated them to Dr. Apjohn. § In practice, I am inclined to prefer two separate thermometers to the dif- ferential one of Leslie, which requires besides, the use of a common thermo- meter, to take the temperature of the air. It seems preferable to have two thermometers arranged in one pocket-case, and in the event of fracture a single one may still be used. I have formerly adverted to the unnecessary introduc- tion of the term psychrometer to express so simple a combination. SUPPLEMENTARY REPORT ON METEOROLOGY. 101 tended the theory ; which was reduced to practice by Auguste and Bohnenberger, who determined the constant with accuracy. English observers have done little more than confirm the con- clusions of our industrious Germanic neighbours ; nevertheless, the experiments of Apjohn and Prinsep must ever be considered as conclusively settling the value of the co-efficient near the one extremity of the scale, as those of Kamtz have done for the other. 188. Of the papers of Dr. Hudson in the Philosophical Maga- zine*, and of Mr. Meikle, and of an anonymous author, in the Edinburgh New Philosophical Journalt, it is not necessary for me to speak, on the grounds just stated. The experiments of the latter have been compared with theory by Dr. Apjohn. B. On the Distribution of Vapour in the Atmosphere. 189. Now that we have got asimple and intelligible hygrome- ter, we may hope to know more than we yet do respecting the distribution of vapour in the atmosphere. Accurate experiments are at present extremely rare; a few of the most interesting have been obtained by M. Kamtz. The greatest dryness he has observed was on the 28th September, 1832, on the summit of the Faulhorn, the barometer 247°4 French lines. At 9 a.m. the temperature of the air was 6°9 R., the moist thermometer fell to 0°-1 R. The computed dryness is 9 per cent. of satura- tiont. Clouds he has always found to be perfectly damp when fully immersed in them, confirming the result of Saussure, which has been called in question §. 190. It has commonly been supposed that dryness increases as we ascend; yet it is also certain, that at a certain elevation clouds are more common than at any other. Accordingly, Kamtz finds that, whilst in dry weather the higher regions are drier than below, in damp weather the reverse is the case; he finds that, if we consider the absolute elasticity of vapour at a given place, there are two maxima and two minima daily; but if we consider the relative humidity, or proportion existing to the capacity of saturation, there remains but a single maximum of dampness at 4—5 a.m. (in June), and one minimum at 2 P.M, 191. The absolute quantity of moisture existing in the air is greatest at the equator, and diminishes towards the poles. M. Kamtz, from the experiments of Beechey and others, gives the following formula|| for the North Atlantic :— * Phil. Mag., 3rd Series, vii. viii. ix. t+ xv. 273; xvii. 98. 330. t Poggendorff, xxx. 71. § Poggendorff, xxx. p, 53, || Poggendorff, xxx. 59. 102 REPORT—1840. Ey = 0°1370 + 8°9004 cos? ¢ in French lines, where Eg is the elasticity of vapour in lat. ¢. IV.— Winp*. 192. The immediate cause of wind is the inequality of pneu- matic pressure in the atmosphere, occasioned by differences (permanent or variable) of temperature. 193. Of Permanent Differences, the most important is the warmth of the equatorial regions compared to the polar. The combination of this cause with the rotation of the earth is the well-known cause of the trade winds ; and, we may add, of the prevalent west winds in northern latitudes, as well as of the counter currents observed at certain elevations. 194. Of Variable Differences of temperature there are very many ;—as (1) the variable temperature of any spot, occasioned by the annual change of position of the sun respecting it ; (2) a similar variation for different hours of the day or night; (3) a variation due to the continental and insular character of climate affecting the annual temperature curve; (4) a similar influ- ence of the solid or fluid, and more or less heat-absorbing, cha- racter of the surface, in varying the distribution of temperature during twenty-four hours ; (5.) the variable nature of surface depending on elevation, such as the presence of mountains, which receive heat from and part with it to the adjacent plains, according to different laws. 195. All these causes produce their peculiar and local effects, which it may be sufficient to advert to in the most general way. To the first cause is due the variation in the position of the limit of the trade winds at different seasons. ‘To the second, the probable tendency of the warmth at the part of the earth’s surface, on which, in his diurnal course, the sun has just exer- cised its greatest energy, to attract the colder air from the parts of the earth on whose horizon he is just appearing. To the third, are attributable the very important effects of the mon- svons, the local variations of the trades (as on the coast of Africa and Mexicoy), the prevalence of east winds in Europe in spring, and many similar phenomena. To the fourth, the recurrence of land and sea breezes in all climates, especially between the tropics. To the fifth, the very remarkable but little-noticed diurnal phenomena of hill and valley breezes, occurring with great regularity in mountainous countries having a pretty uniform climate (as in the South of Europe), and * See former Report, p. 246. Mahlmann, p. 155. + See Capt. Hall’s Fragments of Voyages and Travels, 2nd Series, ii., and Daniell’s Meteorological Essays, 2nd Edition. SUPPLEMENTARY REPORT ON METEOROLOGY. 103 which, especially in their connexion with moisture, have a most important influence on climate. 196. All these phenomena deserve a more careful examination than they have received, with a philosophical view of referring them to their common cause. What has been done in this way we will presently notice. But first, we will say something as to means of investigation. A. Anemometers. 197. In my former report I remarked, that if anything were to be done in the way of anemometrical observations, it must be by the use of self-registering instruments. Two such have been invented, and pretty extensively used in this country. 198. Mr. Whewell* has described an anemometer proceeding on the ingenious principle, that the meteorological importance of a wind blowing in a given direction is not to be estimated by the number of days or hours that it blows in a given direction, but by the compound ratio of the time and force. This he endeavours to obtain by causing a pencil to describe a vertical line with a velocity proportional to the number of turns of a vane with which it is connected, whilst at the same time the pencil is carried round a cylindric surface by an apparatus like that which guides a windmill, so as to point out the azimuth of the wind. The length of line described by the pencil between two given azimuths shows the integral effect of force and time for that interval. The instrument has been worked with very considerable success at Cambridge, under the directions of Professors Whewell end Challist, at Plymouth by Mr. South- wood{, at Edinburgh by Mr. Rankine§ and myself, and in other places. From its construction (friction being the anta- gonist force or regulator), perfect comparability cannot be ex- pected. 199. Mr. Osler, of Birmingham, has invented and constructed an ingenious but complicated apparatus for measuring the force and direction of the wind at any moment, and for keeping a re- gister of these particulars in the absence of the observer||. It consists of a very powerful vane, which carries round the stalk to which it is affixed ; this stalk terminating in a pinion, moves a rack connected with a pencil, which describes upon paper the * Cambridge Transactions, vol. vi. part ii. + British Association, 7th Report, Sections, p. 32, and Camb. Transactions. t Ibid., 8th Report, p. 28. § Edin. Trans. xiv. 359. || British Association, 7th Report, Sections, p. 33, and “ Description of a Self-Registering Anemometer and Rain-Gauge.” 4to.. Birmingham, 1839, with a plate. Some parts of the apparatus have been more lately modified. 104 REPORT—1840. variations in the direction of the wind, the paper being carried uniformly along beneath the pencil by means of clockwork, so that the pencil describes a Curve of Direction of the Wind. The force is registered by means of a plate one foot square con- nected with the vane-stalk by a jointed parallelogram ; which plate is pressed against a spiral spring in such a manner as to indicate the force of the wind by the antagonist force of the spring in pounds. To indicate this upon the same sheet of paper before mentioned, and with regard to time, a thread con- nected with the pressure plate is conveyed through the axis of the vane-stalk (which is hollow), and then turning over a pulley, pulls a pencil up or down as the intensity increases or diminishes, leaving an intelligible tracing on the paper, from which the mean pressure may be tolerably estimated*. The fall of rain is registered by a peculiar contrivance upon the same sheet, so as to indicate its amount and distribution over the twenty-four hours, The expense of the instrument and its liability to derangement are the chief objections to it; it is evi- dent that so many objects cannot be gained without consider- able complicationt. One of these anemometers has been work- ed for a considerable time at Birmingham, and another at Ply- mouth{. One has just been established at Edinburgh, and others, it is believed, have been sent to Ireland and America. 200. Mr. R. Adie, of Liverpool, has contrived a statical wind- gauge, in which the maximum pressure is pointed out. It is on the principle of a gasometer with a moveable top, over water, and the pressure of the wind is introduced by a tube below. The pressure is indicated by a hand connected with an axis, which is turned as the moveable top rises against a gra- duated resistance §. B. Phenomena of Wind generally. 201. It is rather remarkable that of late years several persons should independently have arrived at partial solutions of the great and complicated problem of aerial currents, their distribu- tion and causes. A few of the simpler admitted facts have al- * As every instrument upon this construction must necessarily act by im- pulsive starts, the statical gradation cannot possibly give the actual force of the wind, but it is difficult to suggest a better measure. + This instrument is in every respect so much more complicated in its parts and delicate in its adjustments than Mr. Whewell’s anemometer, that it is difficult to understand how the latter comes to be described in the Royal Society’s Instructions (p. 71.) as “ more complex in its construction, and prac- tically more liable to derangement.” t See Reports of the Ninth Meeting of the British Association. § See a figure in Dr, Traill’s article on Physical Geography, from the Ency- clopedia Britannica, 8vo, p. 197. SUPPLEMENTARY REPORT ON METEOROLOGY. 105 ready been mentioned, which serve to explain the more formal modifications of wind by a combination of the principles of rarefaction by heat, and the mechanical rotation of the globe. The particle of air, thus drawn toward the equatorial regions by the rarefaction permanently produced there by the sun’s verticality, lags behind the parallel of latitude over which it moves, having the velocity due to a higher latitude from which it has come. That there must be a return current is not only evident to common sense, but its existence is made evident by the drift of clouds in the neighbourhood of the tropics, and by observations at great elevations ; not to mention that the preva- lent S. and S.W. winds of our latitudes appear to be nothing else than portions of this superior return current, which, in this stage of its progress, falls again to the surface of the earth, pos- sessed of the excess of velocity of a more southern parallel. 202. These doctrines are now generally held, but there have been various attempts made to carry out the theory and to ge- neralize the facts further, even as respects the apparently capri- cious changes of wind in this most anomalous region of the earth’s surface. It even appears probable that our forefathers knew more on this subject than is generally admitted now, and the sagacious guesses of the seventeenth century may be brought in support of the probable theoretical conjectures of the nineteenth. 203. Professor Dove, of Berlin, author of several original re- searches in meteorology, optics, and magnetism, and editor of a valuable scientific work of reference*, has published a series of elaborate memoirs more or less connected with the theory of wind}, of which he has more lately published a compend f, but whose labours on this subject seem to be little, if at all, known in this country. This perhaps is to be attributed to the want of a perspicuous analysis of his views by some one who would undertake clearly to state, how far they are original and how far combined from those of others, how far they are to be con- sidered hypothetical and how far founded upon demonstration. We feel the want of some such guide in turning over Prof. Dove’s three hundred and forty-four closely-printed pages, and also in the writings of his countrymen who have acted as commen- tators§. Iam by no means satisfied that I am so thoroughly possessed of his views as to give all that Prof. Dove claims to * Repertorium, of which 3 volumes are published. + Alist of 14 memoirs contained in Poggendorff’s Annals between the 11th and 36th vols. will be found in his “ Untersuchungen,” p. viii. t Meteorologische Untersuchungen, von H. W. Dove. Berlin, 1837. 8vo. § Fechner, in his Repertorium, vol. iii.; Kamtz, in his Meteorologie, i, 254; Mahlmana, in his enlarged Translation of my last Report, p. 155. 106 REPORT—1840. establish, but in stating briefly what I understand to be his fundamental positions, I shall at least have a better chance of rendering myself understood, than if I confined myself to the easier task of translating passages from the original works. 204. Considering first the simple phenomenon of the dzrec- tion of the wind, apart from all others, it appears for ages to have been a belief that when the wind changes it does so ina constant direction, which is that of the hands of a watch, which for brevity we will call a Right-handed Rotation. M. Dove contrasts, not unaptly, the two following passages, one from Bacon, in the commencement of the 17th century, the other from a French physical writer of the 19th. The former says, ‘“‘Si ventus se mutet conformiter ad motum solis, non revertitur plerumque aut si hoc facit fit ad breve tempus ;” the latter, “On a cru remarquer que dans certains lieux les vents se succedent dans un ordre déterminé; mais ces observations présentent encore trop d’incertitudes pour qu’il nous soit per- mis de les discuter ici’’. The clear evidence which Dove pro- duces of the opinion of observers of various countries during a space of two hundred years, that the more freyuent and more per- manentrotations ofthe windare right-handed (in this hemisphere), give much support to his theory*. It is important to add, that the phenomena of the trade winds and monsoons enter as part of the expression of his general law of rotation (das Drehungs- gezets des Windes). 205. It is very remarkable, from its connexion with a different inquiry presently to be noticed, that in the Southern Hemisphere the Law of Rotation is inverted, the movement of direction is Left-handed. In the Northern Hemisphere the order of winds is Peed Vite. Ning Bes In the Southern Hemisphere, sca Nag WY oy ots Of these circuits, the quadrants from S. to W. and N. to E. in the Northern Hemisphere, and from N. to W. and S. to E. in the Southern Hemisphere, are oftener traversed in an inverted order than the opposite quadrants}. 206. This, however, is only a small part of M. Dove’s investi- gation, for he aims at showing that this law of succession thus determined, renders a certain order of meteorological pheno- mena of every kind indispensable, and he has laboured to assign * Meteorologische Untersuchungen, p. 132. Itisimportant to observe, that the direction of rotation here mentioned has no reference to the rotatory movement of the aerial particles themselves, which will be referred to in the next section. + Meteorologische Untersuchungen, p. 129. It is to be observed, that this Law of Rotation especially applies to extra-tropical regions, where the mixture of equatorial and polar currents is most complete. SUPPLEMENTARY REPORT ON METEOROLOGY. 107 for each hemisphere an invariable concomitance of the meteor- ological phenomena of temperature, pressure, humidity and rain for every direction of the wind. This research was indeed by no means new. Von Buch had shown the depend- ence of the barometer on the direction of the wind; even the poets could distinguish the thermal and hygrometric charac- ters of Boreas and Zephyr ; and it is easy to see that as far as the characters of North and South go, these particulars must be altered in the southern hemisphere. In my former report I have shown, from the researches of the German meteorolo- gists, that the mean direction of the wind for the whole year depends on the climate*, and I might have added that the sea- son exerts an important influence :— 207. Thus at Berlin the mean direction of the wind is + Proportion of E. to W. Winds. N. to S. Winds. Winter S. 33° W. ... 100: 137 .. . 100: 190 Spring S. 73° W. ... 100: 132... 100: 113 Summer N. 83° W. ... 100:277... 4100: 85! Autumn S. 50° W. ... 100: 160... 100: 167 Each season therefore has its predominant wind, as it has its characteristic temperature, pressure and moisture. It is Prof. Dove’s object to prove that these follow as cause and effect, and hence that any law affecting the succession of winds must affect the succession of other meteorological phenomena. It must be owned that the following table of one year’s observations at Calcutta give a strong probability to the general mutual de- pendence of these phenomena upon one another in those regions, where atmospheric laws are usually exhibited with vast dis- turbance, and therefore more correctly (at least in proportion to the time that the observations have been continued). Temp. Rain, | Barom. liga ee ticki! NE | ‘mana git Inch. Inch. |Direction reckoned Approx. from S.by W. | Direction. January...| 666 | ..... 30:08 156° N.N.W. February .| 75 2:9 30°02 80 W.S.W. March ...| 79 0-5 29°95 355 Ss. April ...... 82:5 8-0 29°83 337 S.S.E WVTAY, o)s0s20. 86 6:0 29°77 348 S.S.E June ...... 83 24-4 29°58 321 S.E 215 eee 83 12:8 29:59 314 S.E August 83 9:3 29°62 299 E.s.E. September.] 83 117 29°71 285 E.S.E. October ...| 83 1-4 29-91 94 w. November.| 75 0:5 29-98 118 W.N.W. December.| 69 Sets 30°01 1385 N.W. * P. 246. + From the Observations of Beguelin, for17 years. See Kamtz and Mahlmann. 108 REPORT—1840. 208. “Since 1827,” says Prof. Dove, “I have published a series of Memoirs in Poggendorff’s Annals, in which I have sought to prove that the totality of the non-periodic meteorological changes of our latitudes reduces itself to a fundamental pheno- menon, which I have called the Law of Rotation of the Wind. The fact of a regulated variation of the direction of the wind (regelmissigen Ueberganges der verschiedenen Windesrich- tungen) observed centuries ago, yet often disputed, stood iso- lated from the generally acknowledged, if not sufficiently proved, influence of the winds’ direction upon the pressure, tempera- ture and humidity of the atmosphere. If, then, the so-called Irregular Variations are nothing else than the transition or passage of the barometrical, thermal and hygrometrical values of the winds into one another, it is clear that the laws of these variations can only be known by ascertaining the laws which connect the mean variations of the wind’s direction with the distribution of pressure, temperature and moisture for the different points of the compass*”’. Such nearly, in the author’s words, are the objects of his more laborious investigations; and to the construction of a barometric compass-card, a ther- mometric compass-card, and so forth, a series of memoirs is devoted. When by this means any mean series of meteorolo- gical changes becomes interpretable in terms of wind-azimuth, it is easy to see that new checks may be obtained for the fun- damental law of rotation. 209. To pursue the course of M. Dove’s laborious research is out of the question. We must content ourselves by gi- ving a specimen of his conclusionst. In the Worthern hemi- sphere The Barometer falls during E. S.E. and S. winds; passes from falling to rising during S.W. and rises with W., N.W. and N. winds, and has its maximum rise with N.E. wind. The Thermometer rises with E., S.E. and S. winds; has its maximum with S.W., and falls with W., N.W. and N. winds ; its minimum is N.E. The Elasticity of Vapour increases with E., S.E. and 8. winds; has its maximum at §.W., and diminishes during the wind’s progress by W. and N.W. to N.; at N.E. it has — a minimum. 210. What has now been stated for the Northern hemisphere may be transferred to the Southern by changing N. into S., N. W. into S.W., &c., throughout. 211. These views of Dove have not been received altogether * Untersuchungen (Pref.). ¢ Untersuchungen, p. 140. | | ' SUPPLEMENTARY REPORT ON METEOROLOGY. 109 without discussion. The mutual dependence of meteorological phenomena in a general way can hardly be disputed, but the fundamental Law of Rotation has been denied by Schouw, who has made this subject his particular study*. The subject now attracts considerable attention in Germany {, and the indications of anemometers, like Osler’s, are well adapted to put it to the test. C. Phenomena of Stormst. 212. The ingenious observations of Franklin on the travelling of storms opposite to the actual movement of the wind which produced them, led to the supposition of local rarefactions and the sudden rush of wind from all quarters to supply the va- cuity. The enormous linear velocity of the aerial particles re- quired to produce the observed effects, to which might be added the difficulty of conceiving this propagation of disturbance to continue for days together, and to pass over hundreds or thou- sands of miles, with unabated intensity, led Colonel Capper to suggest in 1801 §, that the velocity of the wind at any point was chiefly due to the velocity of rotation of a vortex of fluid, com- bined probably with a progressive motion. Prof. Mitchell, of America, seems to have retrograded when he assigned to the gyration a vertical plane of motion||; but he was speedily fol- lowed by Redfield, who, doing all justice to those who preceded him, established Colonel Capper’s doctrine by a diligent appeal to facts]. Mr. Redfield has been fortunate also in having a Eu- ropean fellow-labourer in the same field, who has been equally candid in his acknowledgements of what he borrowed from Ame- rica. Colonel Reid, in a handsome and elaborate work**, has maintained the same views, and supported them by an examina- * See Kamtz, i., 257, and Pogg. xiv. 546. See also Schouw’s extensive Essay on the Winds of Europe, “ Beitrdge”, &c., p. 1—115. + See Galle’s papers on the Extension of Dove’s Law to the Southern He- misphere. Poggendorff, xxxi. 465 ; xxxviii. 472. ft First Report, p. 248. § Ina work on the Monsoons and periodical winds, quoted by Redfield, Reid, and others. {| Silliman’s Journal, 1831, xix. 248. §] His first paper is in Silliman’s Journal, 1831, xx. 17. There is a reply to him by Mitchell in the same volume. See also London Nautical Magazine, April, 1836, and Jan. 1839, and Silliman, xxx. 115. ** On the Law of Storms. 8vo. London, 1838. An interesting review of this work, and of the previous labours of Redfield, will be found in the Edinburgh Review, Ixviii. 406, to which those readers who wish a popular compend of the subject are referred. Since these pages were written, Prof. Dove has ex- plicitly claimed the credit (Phil. Mag., Nov. 1840,) of having first in recent times asserted the revolving and progressive character of storms, and their op- posite character in the two hemispheres.—Compare Pogg. xiii. 596. 110 REPORT—1840. tion of the courses of many hurricanes recorded in ships’ logs, which he has projected on excellent charts. The theory of Colonel Capper proposed for the storms of the eastern hemi- sphere is found to be not less applicable to the terrific tem- pests of the West Indies, where these gyratory movements ap- pear commonly to take their rise, invariably revolving from right to left, which at the same time progress in a straight or curved path, usually occupying a space of from 100 to 500 miles in diameter. These rotatory movements commence in tropical latitudes usually near the West India Islands; they move at first in a westerly and continually more northerly di- rection, until they reach a latitude of about 30°, when they turn rather abruptly towards the north-east. It is impossible not to believe that the path of these storms is mainly determined by the configuration of the American continent *. 213. The fall of the barometer, especially near the central parts of the storm, is accounted for by the action of centrifugal force. 214. It is very evident that the direction of the wind to a sta- tionary observer, whilst one of these vortices is passing over him, will vary in a manner depending on his position with respect to the axis of the storm. If the centre pass rigorously over his station, he will experience a gale first in one direction and then in a directly opposite one, without any intermediate points of the compass; as an observer is stationed on one side of the axis or the other, a little reflection will clearly show that the appa- rent change in the wind’s direction will follow opposite courses in the one or other position. This and many other deductions are fully made by Redfield and Reid; we only mention it just now in order to point out that this, at all events, must be con- sidered an essential exception to Dove’s law of rotation. 215. There is, however, a remarkable analogy to Dove’s law in one respect, which is, that the direction of rotation of storms is opposite in the two hemispheres, being right-handed in the southern. This important fact was deduced by Redfield from his hypothesis that storms are produced by the mingling and collision of the superior equatorial stream with the polar stream or trade winds. Colonel Reid has given great support to this view by tracing some storms of the southern tropical regions. 216. Not the least important and interesting part of this in- quiry is the deduction of practical rules for steering out of in- stead of into these vortices, an application distinctly pointed out by Col. Capper as well as his successors ; but this does not con- cern us at present. * See Colonel Reid’s Charts, iii., v., vii. SUPPLEMENTARY REPORT ON METEOROLOGY. 111 217. The theory of Capper, Redfield, and Reid has not been received without opposition. Mr. Espy*, in particular, advo- cates the Franklinian doctrine of the progression of wind in radial lines ; and he has received the powerful support of Prof. Bache, of Philadelphia, who has described, in great detail, a tornadot which occurred in New Brunswick in 1835, and from which he finds no proof of rotation. Mr. Milnet has traced, I think satisfactorily, the rotatory character of two remarkable storms which passed over the British Islands in November, 1838, ac- companied with an extraordinary depression of the barometer of a very local character. M. Arago is disposed to admit, that there may be hurricanes of both characters, and, consequently, observations irreconcileable with either hypothesis singly §. V.—C.Lovups—Rain ||. 918. The theory of the suspension of clouds, one of the most interesting in the whole range of meteorology, has received no additions, nay, it can hardly be said to exist. That clouds con- sist of distinct particles is undoubted, from optical phenomena, and from direct observation]; the error seems to be, to con- sider these as so many independent molecules, whereas they are no doubt connected by the most definite laws of force, and con- stitute masses whose density has no necessary connexion with that of their integrant parts. No one can observe the chu- racter of clouds—for instance, the well-formed cauliflower- * Journal, Franklin Institute, October, 1836. Not having been able to pro- cure this journal, I cannot refer to the contents more particularly. Mr. Espy maintains a peculiar physical theory of storms, which, since this report was written, has been brought in several forms before the British public.—See also Silliman, xxxix. 120. Dr. Hare has published, in the American Philosophical Transactions, and in Silliman’s Journal (vol. xxxviii.), some papers respecting tornadoes, in which he appears to assign to them an electrical cause. Major Sabine has referred me to a clear and able analysis of the effects of the storm of the 20th December, 1836, by Mr. Loomis, in the first part of the 7th vol. of the American Transactions (which had not reached Scotland when this report was written), who appears to infer, in that particular case, a rotation round a horizontal axis like that imagined by Mitchell. The paper is highly worthy of consultation. + Trans. American Phil. Soc., v. 407. It seems rather singular, that the name of tornado or whirlwind should be applied, by common consent, to a storm not having the rotatory character. Mr. Redfield denies Mr. Espy’s and Prof. Bache’s conclusions (Nautical Magazine, January, 1839, p. 6.). See also the Report of the Newcastle (Eighth) Meeting of the British Association, where Colonel Reid and Prof. Bache were present. { Edinb. Trans., vol. xiv. § Comptes Rendus (Paris), vii. 707. | Former Report, p. 249. Mahlmann, p. 185. §] Since writing the former report, I have satisfied myself of the existence and some of the phenomena of Saussure’s (so called) vesicular vapours. 142 REPORT—1840. headed cumulus contrasted with the flaky cirrus—without being persuaded of the fact, that clouds are not unorganized assem- blages of watery particles in a state of extreme division. 219. With respect to the fall of rain, by far the most inter- esting contribution to this part of meteorology, took its origin at the rise of the British Association. Prof. Phillips, by his careful experiments on the fall of rain at different elevations at York, and his admirable deductions from them, has (I think) completely established the cause of the diminished fall of rain, as we ascend in the atmosphere (vertically above the soil). M. Boisgiraud ainé, of Toulouse*, was, I believe, the first in recent times} to maintain that this is due to the gathering of the drop as it descends, chiefly in consequence of the cold which it possesses, due to the height from which it has fallen, and also to the considerable dampness of the atmosphere at such times. This, the experiments of Mr. Phillips and Mr. Gray entirely confirm, and I think demonstrate f. 220. For 12 months (1833-34) the fall of rain at York was as follows :— Height above Ground. Rain in Inches. if feet ropes); 2. sai) er ROR Ad: ogy acs is Mellen) oo) ORO DSO, GixwNoad Giese wile om). Wha aine The diminution was, therefore, 41°8 per cent. for 213 feet. 29 22°8 29 44 5, which is pretty nearly as the square root of the height. This proportion does not hold for different seasons ; and though the formula m 7 height, originally proposed by Mr. Phillips (m being a function of the air-temperature), is a tolerable approxi- mation, it does not appear to be an accurate one. Nor indeed have we any reason to suppose that so simple a law should express the effect, on the author’s own hypothesis, since (ad- mitting that the rain-drops have attained a terminal velocity) the deposition on the drop must involve the size of the drop, the dryness of the air, and the decrement of temperature in the atmosphere in a very complicated manner §. 221. Admitting, however, for a moment, Mr. Phillips’s ori- * Annales de Chimie, xxxiii. 417. + Prof. Bache, of Philadelphia, has claimed, with reason, for Dr. Franklin, the merit of first suggesting the explanation, so far as the imperfect science of his time would fairly allow him to do.—Journal, Franklin Institute, vol. xvii. 1836. t British Association, 3rd Report, p. 401; 4th Report, p. 560; 5th Report, pel Writ § The optical phenomena of the rainbow, to which we shall presently ad- vert, confirm, in a remarkable manner, the increased size of drops in falling. —See Arago; Annuaire, 1836, p. 301. SUPPLEMENTARY REPORT ON METEOROLOGY. 113 ginal approximation, we think that he has fully made out his main point ; for he has shown* that the value of the co-efficient m depends upon the dryness of the air, at least that it is very nearly inversely as the mean daily range at any season, a datum which, in a good degree, indicates the relative dryness ; although without direct hygrometrical experiments the investigation must be considered as incomplete. Mr. Phillips desires that these experiments should be further pursued at points where three rain stations, vertically above one another, can be procured, and he has given instructions for making such observationsy{. 222. Prof. Bache, of Philadelphia, has shown the very mate- rial influence which the eddies of air surrounding a station, such as a tower or steeple, exert upon the fall of rain, depending on the position of the gauget. Mr. Phillips is at present engaged in an ingenious series of experiments, to estimate and elimi- nate these disturbances. 223. An admirable list of rain-gauge experiments, in differ- ent parts of the earth’s surface, is given in Prof. Muncke’s ar- ticle on Rain, in Gehler’s Physikalisches Worterbuch§, an elaborate treatise, which appears to exhaust the literature of the subject. 224, It appears from the Report of the Birmingham Meeting of the British Association, as given in the dtheneum journal ||, that doubt has been thrown upon the statement of the remark- able fall of rain cited in my former report]. I was not pre- sent at either of the discussions alluded to ; I therefore take this opportunity of stating the authority upon which these very sur- prising falls of rain were admitted into my report—authority so ample, that, as a historian of science, I could not have omitted them, improbable as they do most certainly appear. 225. The fall of 30 inches of rain within 24 hours took place at Genoa** on the 25th October, 1822. An assertion to this ef- fect having appeared in a Genoese newspaper, the editors of the Bibliotheque Universelle wrote immediately to make the ne- cessary inquiries as to an observation so unprecedented. The reply, which they obtained from M. Pagano, “ observateur exact,” is given at length in this journal}7, and is, I think, by no means the less satisfactory because it was obtained by the most inartificial of rain-gauges :—‘‘ Deux sceaux de bois, presque cylindriques, dont l’un de vingt-quatre et l’autre de vingt- * British Association, Third Report, p. 410. T Ibid., 5th Rep., p. 178. t Ibid., Eighth Report, Sections, p. 25. § Vol. vii. Part Il. p. 1309. Leipzig, 1834. || 31st August, 1839, p. 658. q P. 252. ** Not Geneva, as stated by a printer’s oversight in the former report; the MS. was correct. tt Vol. xxii., Partie Physique, p. 67. VOL. Ix. 1840. I 114 REPORT—1840. six pouces de hauteur, qui m’avoient servi pour quelques expé- riences sur la vendange étoient restés vides dans mon jardin. La pluie de Vendredi 25 Octobre, n’avoient pas encore cessé de tomber, que déja ils en étoient remplis.” He then proceeds to state on what grounds he infers that 4 inches more of rain fell after the largest vessel was filled, making a total of 30 French (32 English) inches, and then adds a statement of several facts, to show that the effects of this delnge in the neighbourhood bore a proportion to the magnitude of the cause. M. Arago, quoting the result, adds, “‘ Ce résultat inoui inspira des doutes 4 tous les météorologistes ; ou soupgonnait une erreur d’impression; mais M. Pagano, observateur exact, a écrit aux rédacteurs de la Bihliothéque Universelle, une lettre qui met le fait hors de toute contestation*.”’ 226. Fortunately, however, this local deluge (for it appears by the letter of M. Pagano to have extended but a very short di- stance), is nearly rivalled by a similar fact recorded in the South of France by an experienced observer (who seems to have been in the practice of measuring the fall of rain for twenty-three years at least), M. Tardy de la Brossy, of Joyeuse, Dép. de VArdéche. M. Arago, who records the observation, and gives it the weight of his authority, does so in these words :—‘ Le 9 Octobre, 1827, dans l’intervalle de vingt-deux heures, il est tombé dans la méme ville de Joyeuse, 29 pouces 3 lignes d’eau (vingt-neuf pouces, trois lignes) ; jécris le résultat en toutes lettres Gfin qu’on ne croie pas a une faute d’impression +.” When I add that these two results, surprising, and perhaps unexampled, as they are in the history of science, have, on account of the testimony by which they are established, been received not only in France{t and Switzerland§, but in Ger- many || and England@, I conceive that they are undoubtedly entitled to stand part of the history of meteorology **. 227. I proceed to add a notice of a few other remarkable falls. * Annales de Chimie, xxvii. 207. Tt Annales de Chimie, xxxvi. 414. } By Arago and Pouillet (Phys. ii. 758.)- § By the Editors of the Bibliothéque Universelle. || By Muncke (Gehler, vii. 1240.), Kamtz (Meteorology, i. 421.), and Mahlmann (Abriss. 200.). J Encyclopedia Metropolitana, Art. Meteorology, p. 120. - ** Mr. Espy has referred me to the fourth volume of Silliman’s Journal for an account of a shower hardly less surprising. At Catskill (U.S.), Mr. Dwight ascertained that on the 26th July, 1819, between half-past 3 p.m. and 11 P.., that is, in seven and a half hours, there fell into an empty barrel placed in an open space eighteen inches of water. A tub 154 inches deep, and nearly cylin- drical, was filled before sunset. Since writing the above, another fact of the same character has come to my knowledge. On the 25th Nov. 1826, thirly-three inches of rain fell at Gibraltar within twenty-six hours. This in- formation I received from Professor Jameson, who believes that he had it from the late Col. Imrie. SUPPLEMENTARY REPORT ON METEOROLOGY. 115 of rain, though there is nothing on record comparable to the two preceding ones. Flaugergues, the eminent meteorologist of Viviers, obtained, on the 6th September, 1801, 13 inches 2°3 lines (144 English inches) of rain in eighteen hours*. On the 20th May, 1827, there fell at Geneva 6 inches of rain in three hourst. At Perth, on the 3rd August, 1829, there fell #ths of an inch of rain in half an hourf. On the 22nd November, 1826, I observed, at Naples, a fall of j4ths of an inch of rain and hail in thirty-seven minutes §. 228. Werethe equatorial records of the fall of rain as minute in respect of distribution as of total amount, we should doubt- less have records of enormous falls within twenty-four hours. None so recorded, that I am aware of, approach the results at Genoa and Joyeuse. From the total quantities measured, it is evident that the result, for particular days, must be enormous. Don Antonio Lago observed, at San Luis Maranham (22° S. lat.) a fall of twenty-three feet, 4 inches, 9°7 lines of rain in a year||. Roussin states§ (his account is confirmed), that at Cayenne (5° N. lat.) in February, 1820, there fell, in ten hours, 10°25 inches of rain; and between the Ist and 24th February, twelve feet 7 inches. From observations in the Ghauts, it ap- pears that in the eastern hemisphere, in lat 18° N., 302-21 inches of rain have been measured**, a quantity exceeding that stated on the authority of Roussin, and which was once considered almost incredible ; and of this quantity (25:2 English feet) nearly 10 feet fell in the month of July alone. 229. I have formerly stated, that the fall of rain increases on mountains}; and the following statement of Schubler, as to the fall of rain at three stations, confirms the facttt : Height. Depth of Rain §§. Wapmeen 7": 1000 feet . 8572 Mchaicuhots 71576" 40° . oo... YB e56 Alp Genkingen 2400 , .. . . 5513 * Bibliothéque Universelle, viii. 132, quoted in Gehler. + Ann. deChim.,xxxvi.414. Themean annualrain at Geneva is only 80 inches. { Edinburgh Journal of Science, New Series, iii. 368. § I donot know whether there exists a record of the fall of rain at Cler- mont, on occasion of the catastrophe of the Valley of Royat, a few years ago; the amount, I presume, must have been very great, judging by the effects. M. Quetelet has recorded a remarkable fall of rain in Belgium (Comptes Rendus, viii. 980.). || Humboldt, quoted by Muncke. {| Silliman’s Journal, iv. 375., quoted by Muncke. ** Communicated by Colonel Sykes, at the Ninth Meeting of the British Association.— Atheneum, p. 658. Prof. Stevelly’s inference from these results must, 1 presume, be erroneously reported. tt Former Report, p, 251. tt In Gehler, vii. 1246. §§ The unit of measure is not stated. 12 116 REPORT—1840. Boussingault finds a contrary result in the tropics*; but this fact admits of easy explanation, for the height to which they were carried had already passed the region of maximum humi- dity, above which, no doubt, increased dryness occurs :-— Metres. Inches. Marmato . . . 1426 171°2—154°4 in 2 different years. Santa Fé de Bogota 2641 100°3 230. Boussingault also notices that, between the tropics, it rains more in the night than in the day, which is the contrary of the case in Kuropet. 231. Where M. Osler’s self-registering gauge is employed, we have the best means of determining the distribution of rain and the intensity of showers. 232. On the somewhat vague subject of the moon’s influence on rain and weather, I must content myself with referring to the recent Memoirs of Aragot, Brandes §, Baumann]|, Eisen- lohr ], Howard**, Kamtztt, Marcet{{, and Schubler§§. |. 233. This subject has made scarcely any progress during the last years. The experiments of Schubler are still the best we possess. M. Arago has collected a number of important facts respecting thunder-storms, and drawn conclusions from them, for which we refer to his popular treatise (J. Colladon, of Geneva, has proposed to make observations on atmospherical VI. ArmosPHERICAL ELeEcrricirTy || * LT’ Institut, No. 148. + See also Schouw on the distribution of Rain.—Edinburgh Philosophical Journal, July, 1836. ~ Annuaire, 1833. § Ueber die Verschiedenen Formen der Wolken, thre Bildung, die Entste- hung des Regens und Hagels, §c.—Beitrage, p. 285. || Untersuchungen iber die Monatliche Perioden in den Verdnderungen unserer Atmosphare.—Tubingen, 1832. q Poggendorff, xxx. 72; xxxv. 141. ** Proceedings of Royal Society, March, 1840. ++ Lehrbuch, iii.411, &c. tt Bibliotheque Universelle, Fev. 1834. §§ Einfluss des Mondes auf die Verdnderungen unserer Atmosphdre. Leip- zig, 1880.—Kastner’s Archiv, v. 169. \||| See former Report, p. 252, and Mahlmann, p. 209, where the subject is very fully treated. I beg again to disclaim any depreciation of the importance of subjects like the present, over which I may pass very lightly, partly on account of the extent of this report, but chiefly because of the difficulty of establishing any general principles, and of offering any definite suggestions for their advancement. q9 Annuaire, 1838. Translated in the Edinburgh Philosophical Journal. SUPPLEMENTARY REPORT ON METEOROLOGY. 117 electricity by means of a multiplier, but with what success we have not heard*. 234. On the subject of hail there is a curious paper by Lecogq, founded on observations made in the neighbourhood of Cler- mont, contained in the Comptes Rendust, and some observa- tions by Beaumont, Buch, and Airy, and on the form of hail- stones in the same work f. VII. Mereors. 235. This subject has occupied by far too much attention during the last few years to be passed over in silence. A very remarkable shower of falling stars attracting general attention in many parts of the world on the night from the 12th to the 13th November, 1832, recalled the attention of philosophers to the fact, that the same night of the year had, on several pre- vious occasions, been similarly distinguished, and especially the 1J—12th November, 1799, when they were observed by Hum- boldt and Bonpland§, as well as in Germany and in Green- land ||. 236. The year 1832 brought a very remarkable occurrence of this kind on the night of the 12—13th November, which was ob- served over the greater part of Europe, to the middle of Russia, and in Arabia. I was at Geneva at the time, and heard much next day of the appearance, which was such as to strike the most heedless person; but as it occurred very early in the morn- ing, I did notsee it. M. Gautier published an account of it]. 237. This attracted attention to the date of the 12th Novem- ber, and several confirmations were soon found of the (at least occasional) periodicity of the meteor on that night. In 1831, they had been observed by M. Berard on the coast of Spain**, and also in Americatt. In 1822 they were seen at Potsdam by M. Kléden; and some other remarkable appearances in No- vember are also mentioned{{. But to return to the order of dates. 238. In 1833 wasa brilliant apparition, especially in America, always on the 12th November ; and these falling stars appeared * See on this subject the Instructions published by the Royal Society, p. 74; and Becquerel’s Work, vol. iv., there referred to; also Kimtz, Meteorologie, ii, 389. t+ Tom. i. p. 324. t iv. 922. On the subject of Hail, see Fechner’s Repertorium, iii. 56. § Voyage, i.519, quoted by Biot. || Arago, Annuaire, 1836, p. 295. q Bibliotheque Universelle, li. 189. See also Arago, Annuaire, 1836, p. 295. Jameson’s Journal, July, 1836. Poggendorff, xxix. 447. ** Annuaire, 1836, 295 note. See, too, Silliman, xxx. 386. Tt Silliman’s Journal, xxvii. 419. tt Poggendorff, xxxviii. 551. 118 REPORT—1840. to radiate from a point in the heavens near y Leonis. They were visible from Mexico to Greenland*. 239. In 1834, the phenomenon was less indubitably marked, for it scarcely appears to have been noticed in Europe; and in America, observers were divided as to its amounting to any- thing unusual; Prof. Olmsted, who was one of the first to sug- gest the periodicity, maintaining that November, 1834, was marked like the previous years}, and Prof. Bache denying itf. 240. The year 1835 must be regarded as a very doubtful one for the November meteors. Still it happens, by what must at least be regarded as a singular coincidence, that a very large meteor was seen in France by M. D’Aubenton, which exploded in the department de ]’Ain on the night of the 13th November, and probably set fire to a cottage§. Sir John Herschel saw a meteor as large as Venus at the Cape of Good Hope on the 14th, but none on the 13th 241. The apparition of November, 1836, was better marked. The meteors were observed in America§]. M. Arago, by ana- lysing various careful observations in France, has shown that, if not comparable to the showers of 1832 and 1833, they were at least numerically above an average**. They were observed in the Oural in lat. 60°++, and their direction was from the constellation Leo ff. 242, It may be doubted whether, in 1837, there was any very decided fall of meteors in November; but I refer below to the recorded observations§§. The weather was not generally very favourable. 243. November, 1838, was not more prolific. Scarcely any notice was taken of the meteors in the Comptes Rendus, and the direct testimony of Quetelet, Herschel, and Benzenberg ||||, show that the phenomenon was, to say the least, not well marked. In America], it was scarcely, if at all, perceptible. 244, In 1839, IT am not aware that any very marked phe- * For 1833. See Silliman, xxv. 354; xxvi. 132; xxix. 376. Poggendorff, xxxi. 159; xxxix. 114 (Greenland). + Silliman, xxix. 167. t Ibid., xxvii. 335; xxviii. 305; xxix. 383. See also Clarke in Silliman, xxx. 869. Poggendorff, xxxiv,. 129. § Comptes Rendus, i. 414. | Ibid., ii. 264. q Silliman, xxx. 386. ** Comptes Rendus, iii. 629. ++ Comptes Rendus, iv.524. }t See also Poggendorff, xxxix. 353; xl. 484. §§ Olmsted in‘Silliman, xxxiii. 379; Sir John Herschel, Transactions of the Meteorological Society, i. 77; Arago, Comptes Rendus, v. 759; Observations at Edinburgh, Philosophical Magazine, Third Series, xii. 85. |\| Bulletin de l Acad. de Bruvzelles, 1838, p. 730. {| Olmsted in Silliman, xxxv. 368. A brilliant fall was seen at many places on the 6th December. See Herrick in Silliman, xxxv. 361; xxxvi. 355. SUPPLEMENTARY REPORT ON METEOROLOGY. 119 nomenon wus observed. Under these circumstances, it is plain that we must use the term periodicity, as applied to these me- teors, with caution. It is quite possible that some cause may determine their recurrence in November in preference to other seasons, and yet that the repetition may not be annual. 245. It is well known that Chladui*, Brandes}, and Ben- zenbergt, have devoted their attention for a long time to these singular meteors; and it is perhaps surprising that we still know so little respecting them. The November periodic me- teor has of course given a fresh interest to these; Biot has pub- lished an astronomical theory §. Bessel has shown that it is improbable that these meteors ever ascend ||. JKirman has given a meteorological hypothesis connected with them, which we have before adverted to§]; and Olmsted** and Wartmann Tf have likewise written memoirs on the hypothesis of their pe- riodicity. 246. But M. Quetelet, of Brussels, examining the records of this subject, has classified the frequency of meteors at different seasons of the year{{; and whilst he finds the middle of No- vember the most prominent period, yet that from the 10th to the 15th August is also well marked. This observation, com- municated to the Brussels Academy 3rd December, 1836§§, was confirmed by M. Arago next year ||||, and, I believe, every subsequent one§jf]. In 1839 they appear to have been very generally observed. M. Quetelet has quoted no less than six- teen years in the present century down to 1837, in which the August meteors have been specially noticed***. * Feuermeteore. See Kimtz, Meteorologie, Band iii. + See an Abstract of his Researches, Silliman, xxviii. 95; and in Quetelet’s Annuaire for 1887. t He has published a new work, which I have not seen, “ Die Sternschnup- pen.” Hambourg, 1839. § Comptes Rendus, iii. 668. || Poggendorff, xlvii. 525. @ See above (44), and Comptes Rendus, x. 21. ¥* Silliman’s Journal, passim. +t Bibliothéque Universelle, N.S. ix. 373. tt Catalogue des principales Apparitions d’Etoiles filantes. Mém. de U Acad. de Bruxelles. §§ Bulletin de V Acad. de Bruxelles, December, 1836 and 1837, p. 79. \|\| Comptes Rendus, v. 183. 347; Silliman, xxxiii. 133; Bulletin de Acad. de Bruvelles, 1838, p. 567. qq Ibid., vii. 443. tom. ix. passim. *et Bulletin, 1837, p. 379. M. Littrow, of Vienna, has observed the me- teors of August, and states that their direction of motion is contrary to that of the earth in its orbit, whilst those of November move parallel to it. (4tt degli Scienzati Italiani, 1839, p. 19.). I learn, by letters from Sir John Herschel and M. Quetelet, that the meteors of August, 1840, have been ob- served both here and in America to radiate from a point.near y Persei. Whilst 120 REPORT—1840. VIII. Aurora Boreauis*. 247. I have little information on this subject to offer in addi- tion to what was formerly given. It is to be regretted, that the system of observation, vigorously commenced by the British Association in 1833, and of which specimens are contained in the report of the Cambridge Meeting, has not been pursued. 1X.—Opricat METEOROLOGY. A. Colour of the Sky and Clouds. 248. The blue colour of the sky has, from a very early period, attracted attention. Leonardo da Vincif, and: many succeeding writers, vaguely attributed it to a mixture of light reflected from the matter of the atmosphere with the darkness of the celestial spaces beyond ; an opinion which Gothe has revivedt. Muncke§ has asserted that the blueness is a mere ocular deception arising from the structure of the eye, but such a doctrine can hardly now be seriously maintained ; and I have elsewhere|| offered an explanation of his fundamental experi- ment. 249. Newton supposed that the blue of the sky is due to very attenuated vapours producing the first tints of the scale of the colours of thin plates. He further attributes the colours of sunset and of clouds generally, as he had done those of most natural bodies, to the varying thickness of such vesicles**. The latter opinion has been revived and illustrated by No- bilitt. 250. Against this theory it may be urged, (1) that the sky appears intensely blue at elevations and under circumstances which forbid us to suppose that vapour can be present at all in a watery or vesicular form (which Newton’s statement di- stinctly supposes), otherwise the hygrometer would attest its existence ; (2) that with respect to clouds, were they coloured by the nature of their surfaces as a soap-bubble is, they would present iridescent bands, and they would not partake, as we see this sheet is passing through the press, I am enabled to add that no decided meteoric appearance has been observed in Noy. 1840 at Paris, or in the West of Europe generally. * See last Report, p. 254. Mahlmann, p. 230. + Traité de la Peinture, quoted in Gehler’s Worterbuch, art. Atmosphare. + Farbenlehre, i. 59, quoted by Humboldt. § Schweigger’s Journal, xxx. 81; and Gehler, wt supra. || Edinburgh Transactions, xiv. 381. { Optics, book ii., part iii., prop. 7. ** Optics, ibid, prop. 5, end. tt Bibliothéque Universelle, 1830, xliv. 337; and Taylor’s Scientific Me- moirs, vol, i. SUPPLEMENTARY REPORT ON METEOROLOGY. 121 them do, of the general glow so common at sunset which is communicated to all objects indifferently, and which ceases when the sun leaves them in the shade; and (3) that the colours of clouds analysed by a prism by Sir D. Brewster* do not appear to be composed as the colours of thin plates are. 251. Mariotte asserted} that the proper colour of air is blue, just as he considers that of water to be green, and as other bodies have peculiar tints. Bouguer revived this doc- trinet, and added to it the consideration, that if air reflect blue light it may be expected to transmit the complementary colour as red (as is stated to be the case with sea-water), and hence he explained the fiery colour of the horizontal sun, and the tints of sunset. This opinion has been adopted by Euler§, Leslie ||, and many later writers, but especially by Brandes, who, in a most ingenious article in Gehler’s Dictionary], has maintained its complete adequacy to the explanation of phe- nomena. 252. This theory must, I think, be considered imperfect rather than erroneous. That the colour of pure air by reflexion is blue, can, I think, hardly be doubted. But that the explanation of the hues of sunset is incomplete, can be doubted by no one who is unable to persuade himself, with Brandes, that the dif- ference of intensity on different evenings is only an ocular deception, or depends on the presence of clouds which receive and repeat the colour. 253. Something more is wanting, then, to the explanation, and many acute writers have supposed that some impurity in the air produces, by its absorptive action and variable quantity, the phenomena in question; and several of these authors com- pare the effect to that of opalescence in turbid fluids, which generally transmit a ruddy beam. Under this head we class Honoratus Fabri**, our countryman Thomas Melvilltt, De- laval{t, Count Maistre§§, and Sir D. Brewster||||. Of these writers, Count Maistre is the only one who suggests that watery vapour, under peculiar mechanical conditions, may be the source of the variable atmospheric hues, ‘‘ producing an * Edinburgh Transactions, xii. 544. Compare Encyclopedia Britannica, art. Optics, p. 510. + Cuvres, i. 299. Leide, 1717. t Traité d’ Optique, p. 365—8. § Letters, ii. 507. || Encyclopedia Britannica, art. Meteorology. 4 Art. Abendréthe, vol.i. p. 4. ** Quoted by Eberhard. Rozier, i. 620. ++ Edinburgh Physical and Literary Essays, p. 81. tt Manchester Memoirs, First Series, ii. 214. §§ Bibliotheque Universelle, November, 1832. \\|| Edinburgh Transactions, xii. 580. 122 REPORT—1840. effect analogous to that of the powder of calcined bones in opaline glass*.” 254. I have endeavoured to show} that the colorific property of watery vapour may not merely be gathered from induction, but demonstrated by direct experiment. MHaving first noticed that high-pressure steam, during a certain stage of condensa- tion, is coloured, and transmits orange-red light, I extended the observation to steam of low pressure. There seems no reason to doubt that the property of vapour, to be coloured in passing from its pure, elastic, colourless state to that com- monly called vesicular (such as it appears in clouds, or in issuing from the spout of a kettle), is a general one, and there- fore that great masses of vapour at any temperature under- going condensation must pass through the colorific stage. Now the development of the brightest atmospheric colours is in- variably attended with change of temperature. And Forster, without the remotest reference to theory, has recorded that the sunset glow is contemporaneous with the dew-point tempera- ture; hence he argues that “ some sudden change produced by the first falling dew is the cause of the simultaneous change of colour in all the clouds then visible{”’.. The application of this doctrine to atmospheric colours, as a prognostic of weather, is likewise evident and satisfactory §. 255. Dry Fogs.—Of atmospheric colours, which may be con- sidered unusual, the blood-red colour of dry fogs, which have occurred at various times over a vast extent of country, is amongst the most remarkable. It is hardly possible to believe that they are not due to the accidental intermixture of foreign matter with the atmosphere. Remarkable fogs of this kind * Edinburgh New Philosophical Journal, vol. xv. Count Maistre explains the colour of water by similar reasoning. He considers it blue for reflected, and yellowish orange for transmitted, light; and the green colour of the sea and some lakes he attributes to diffused particles which reflect a portion of the transmitted tint, and mingle with the blue. This is well confirmed by Davy’s observations (Salmonia, third edition, p. 317). Arago has very ingeniously applied the same reasoning to the ocean, showing that when calm it must be blue, but when ruffled, the waves, acting the part of prisms, refract to the eye some of the transmitted light from the interior, and it then appears green (Comptes Rendus, 23rd July, 1838). Most authors have admitted the intrinsic blue or green colour of pure water, as Newton (Optics, b. i. part ii. prop. 10), Mariotte, and Ever. Humboldt seems doubtful (Voyage, 8vo, ii. 133.). ¢ “On the Colour of Steam under certain circumstances.” ‘ On the Colours of the Atmosphere.”—Edinburgh Transactions, xiv. 371; Philoso- phical Magazine, Third Series, xiv. 121,419; xv. 25; and Poggendorff’s Annalen. + Researches about Atmospheric Phenomena, third edition, p. 87. § Those who wish for fuller details on the history of this part of the sub- jeet, will find them in my papers above referred to. SUPPLEMENTARY REPORT ON METEOROLOGY. 123 occurred in 1783 and 1831; on both occasions they extended from Europe to America; the former lasted a month, and enveloped the highest Alpine summits*. 256. Blue Sun.—At the latter date (1831) the sun’s dise was seen of a blue or green colour in the South of Europe and in America. This extraordinary phenomenon we might be dis- posed to attribute, with M. Aragoy, to an ocular deception arising from the intense contrasted orange of the fog, did we not find that it has been repeatedly observed under circum- stances to which this explanation would perhaps hardly apply. M. Babinet, a skilful observer, has seen it twice himself t. He accounts for it by Dr. Young’s theory of mixed plates, in which colour is produced by the interference of two pencils of light which have passed through unequal thicknesses of a re- tarding medium. This he supposes may be the case in the atmosphere by the union of rays ‘‘ which have passed through vesicles of water or vapour with those which have passed through air only.” Now, though M. Babinet has ingeniously imitated the effect by a thin film of mixed air and water placed between two glasses, there is some difficulty in conceiving an extended medium like the atmosphere, which should present an analogous constitution §. 257. Secondary Sunset Tints.—Many authors have described the appearance of a revival of the sunset glow upon the sum- mits of lofty mountains long after apparent sunset, and ten or fifteen minutes after the tints which accompanied it have dis- appeared ||. The appearance in question was once noticed with extraordinery effect by the writer of this report, in the case of the Jung Frau seen from the profound valley of Lauterbrun- nen, from which the sun had so long disappeared that it was almost night below, whilst the upper half of the snowy moun- tain was illuminated by a delicate but intense red tint, like that of a glowing coal. Prof. de la Rive has offered as an explana- * Annuaire, 1832, p. 244. + Annuaire, p. 249. t Comptes Rendus, viii. 306. Sir D. Brewster communicated at Glasgow an account of this phenomenon, observed by Dr. Harvey at Bermuda. See Athenzeum, 3rd October, 1840. The appearance referred to occurring on the 10th August, 1831, is evidently part of the same widely-extended appearance quoted by M. Arago in the Annuaire for 1832. Dr. Harvey, however, does not appear to have observed the blueness of the swn’s disc, but only that of objects illuminated by it ;—a circumstance, which, had it stood alone, might pro- bably have been accounted for by the doctrine of accidental colours. § The phenomenon of the scintillation of the stars has lately engaged the attention of M. Arago, who states (Comptes Rendus, 1840) that he has disco- vered a complete explanation of it founded on the laws of the interference of light. || Germ. “ Gliihen der Alpen.” See Brandes in Gehler, art. 4lmosphare. 124 REPORT—1840. tion of this phenomenon*, that it occurs when the air is ex- tremely clear and highly charged with humidity (as we should expect from (254.)), and that the rays which then reach the mountain have undergone total internal reflexion in the higher and moister strata of the atmosphere. 258. derial Shadows.—We do not by this refer to shadows of persons thrown on clouds surrounded by coloured glories, of which we will afterwards speak, but of shadows of clouds and other objects projected to a great distance in the air, and which being rendered visible by its imperfect transparency, produce cer- tain remarkable effects of perspective. The diverging rays so often seen proceeding from the sun, when near setting, are of this kind; and the corresponding fact of rays (or clear intervals between the shadows of clouds), which appear to converge to a point diametrically opposite to the sun. This rarer phzeno- menon we have twice seen; once, combined with a rainbow, to whose centre of course the rays were directed ; and lately, from the summit of Goatfell in Arran, whence the rays appeared directed to a point in the sea, and converging from all sides of the circumference. We chiefly mention the circumstance to call attention to a curious and elaborate paper by Professor Necker+, of Geneva, who undertakes to prove that diverging solar rays are sometimes produced by very distant mountains, and that they thus picture forth, to inhabitants of our country, spectral outlines of mountain-chains in another, far removed from direct vision. 259. Polarization of Sky-light.—Sir D. Brewster appears to have been the first to remark that the light of the blue sky exhibits traces of polarizationt. I apprehend that it must be difficult to assert that the blue rays are actually so polarized, for the polarization of the white light, with which no doubt the blue is diluted, would produce the effects observed. I do not, however, doubt that such is the case. 260. M. Arago determined the polarizing angle for air to be 45° nearly §, and the maximum polarization of the sky to be 90° from the sun’s disc, the polarization being in a plane passing through the eye and the sun. It is a singular fact, and one difficult of explanation, that, proceeding to a greater distance than 90° (in a vertical plane), the polarization diminishes, be- comes zero, and reappears in a plane perpendicular to the * British Association, Seventh Report, Sections, p. 10. See too a paper by Prof. Necker, of Geneva, Phil. Mag., 3rd series, i. 335. + Annales de Chimie, Fev. Mars, 1839, and Bibliotheque Universelle, xxiil. 355. t Treatise on New Philosophical Instruments, p. 350. Edinburgh, 1813. § Biot, Traitée de Physique, iv. 289. SUPPLEMENTARY REPORT ON METEOROLOGY. 125 former*. The distance of the neutral point from the sun varies with atmospheric contingencies. The position of this neutral point seems to have been at first inaccurately reported, for we find English observers searching for it in the sun’s neighbour- hood, and not in the opposite quarter of the skyf. The polariscopes of Arago and Savart, used for detecting the minutest quantities of polarized light, are little known in this country ; it is by their aid that the light of the moon is ascer- tained to be slightly polarized. 261. On the phenomena of Mirage we have nothing new to state. The phenomena of Twilight and of Atmospherical Re- fraction, although connected with Optical Meteorology, we shall also omit. B. The Rainbow. 262. There is no step in the progress of science more inter- esting than that which calls in the aid of comparatively abs- truse principles to explain the slighter outstanding variations between theory and observation, which were overlooked in the first unqualified satisfaction with which the announcement of a simple general principle, harmonizing with every-day experi- ence, is invariably received. Amongst such cases may be reckoned the law of double refraction in crystals with two axes, Laplace’s correction for the velocity of sound,—and we may now add, the phenomena of the rainbow, so far as these were not included in Newton’s general explanation. 263. The diameter of the primary rainbow (caused by two refractions with one intermediate reflexion), and of the secondary (caused by two refractions and two reflexions), may be most easily found by the formule which M. Babinet has lately given { for expressing the radii 5, directly in terms of the re- fractive index of water m, viz. _ (4—m’)? 27 m* . & m*+18 m*—2 For the secondary, sin a eee * See Peclet, Zraité de Physique, 4me edit. art. 1448. I am unable to state where M. Arago’s original account of these experiments is to be found. Compare Quetelet’s Notes to Herschel on Light, French Translation, ii. 554. + Airy and Chevallier, Philosophical Magazine, N.S., iv. 312, 313. I must add, however, that a very recent communication by M. Babinet to the French Academy of Sciences (Comptes Rendus, 19th October, 1840) states the exist- ence of a second neutral point, 20° or 30° distant from the sun. $ Comptes Rendus, iv. 646. The demonstration is given in Peclet, Zraiié de Physique, 4me édit. art. 1489. : yao For the primary, sin? > \ 126 REPORT—1840. sy we obtain Pie che ArsEoP sd! Li, os Ee gga For the second . . . . 50°59), 264. The comparison of these theoretical angles with obser- vation is not so easy as might appear, depending (1) on the doubt which ray of the red space we are to consider as the last visible one in the rainbow, and (2) on the gradual shading off depending on the sun’s apparent diameter. There is reason to think that the measures of the rainbow require revision ; but we would rather place the fate of the theory upon other grounds. 265. The first fact which Newton’s theory did not embrace, was the existence of supernumerary or spurious bows ; within the Inner, or Primary Rainbow, and without the Outer, or Secondary one. These were very accurately described by Langwith in 1722 +,—three internal rings of green and purple (with traces of a fourth) associated with the primary rainbow. The much rarer phenomenonof the supernumerary exterior bows of the secondary rainbow has been noticed by Dicquemare { and Brewster§. The supernumeraries have the same order of colours as the bows to which they belong, 7. e. those within the Primary have the Red exteriorly, those without the Secondary the Red interiorly. 266. Pemberton || explained these spurious bows by the colours of thin plates ; and at a much later period Venturi J attempted to account for them by the deviation of the figure of falling drops from sphericity. Such fallacious endeavours show how cautiously we should receive explanations of such phenomena on the grounds of general plausibility. The true explanation had already been given by Dr. Young, who in pur- suing his fertile discovery of interference, pointed out its appli- cation to the rainbow ina manner so clear**, that it is surprising how for thirty years, this, one of its happiest adaptations to phenomena, has been so generally overlooked. 267. In the ordinary geometrical theory of the primary rain- Adopting with Newton * the index m = * Optics, book i. part ii. prop. 9. + Philosophical Transactions, 1723, quoted by Dr. Young. Dr. Young cites Mariotte as the first who mentions supernumerary bows (Chromatics, Encye. Britt.), but without a reference. t Quoted by Young, Lectures, vol. ii. p. 316. § Edinburgh Journal of Science, vol. x. p. 163. || Philosophical Transactions, 1723, quoted by Dr. Young. {| Commentari sopra la Storia et le Teorie dell Ottica. Bologna, 1814. Quoted by Dove and Kamtz (Meteor. iii. 165). ** Phil. Trans. 1804. Read Nov. 24, 1803. Lectures, vol. i. 470; ii. 316. SUPPLEMENTARY REPORT ON METEOROLOGY. 127 bow, it is well understood that a limit of deviation, due to two refractions and one reflexion of the sun’s light within the drop is adefinite and impassible one. The illumination of the bow is produced by the accumulation of rays near the limit of maximum deviation ; an incidence a little greater or a little less than that due to the limit will equally give a smaller deviation ; and as in a shower there are assumed to be drops which shall send rays to the eye in any given direction consistent with the relative position of the observer and the sun, rays more or less approach- ing to parallelism (therefore more or less densely luminous) will reach the eye from drops placed so as to furnish rays at less angles than that of extreme deviation. Confining our attention to a single colour (the red, for instance, which is the outermost in the primary rainbow), we should expect to find a red bow, quite sharply terminated exteriorly, but shading off gradually, though pretty rapidly, towards the interior. When we recollect, too, that this reflexion within the angle of maximum deviation is derived from rays which have fallen at a smaller as well as at a greater angle of incidence than the critical one, and which therefore emerge rigorously parallel, we are surprised at first sight that the insulation of the colours in the successive arcs should be as great as it appears to be. 268. The doctrines of physical optics, as laid down by Dr. Young, enable us to explain this satisfactorily ; for the very re- duplication of the reflected light just alluded to (which a very little reflection will show to be derived from opposite halves of the drop, separated by the position of critical internal reflexion for producing the maximum deviation) reminds us of the funda- mental fact of interference, that annihilation as well as increase of light may attend the union of rays proceeding in a common direction, derived from a common source, but which have tra- versed paths of different lengths. Whilst, then, near the critical angle of reflexion the luminiferous waves necessarily reach the eye in the same, or nearly the same phase, the rays derived from a greater and a less incidence have (though they ultimately coincide in direction) described paths whose difference will soon amount to half an undulation, when their effects will be mutually destructive. Thus by the principle of interference the bow of any colour has its interior boundary far more sharpl defined than if such a cause (which is manifestly modified by the size of the drop) had not existed*. * See Young’s original paper, Phil. Trans. 1804, where he estimates the pos- sible breadth of the diffused zone of light, which otherwise would have shaded off from the rainbow, at 25°. 128 REPORT—1840. 269. Thus, but for interference, we should have had but a feeble andimpure rainbow. But further, the same considerations explain the supernumerary arcs: for it is evident, from what has now been stated, that after destruction of light by opposi- tion of phases has been produced, an equal additional retarda- tion of the one ray upon the other will produce concurrence of phase, and double light ; hence, as in all similar cases, a series of luminous bands rapidly diminishing in breadth and in intensity will be formed with more or less vividness, depending upon the brilliancy of the reflexion and the separation of the bands (which again depends on the size of the drop). The distance between the true and spurious bow gives the data (upon prin- ciples which will be very readily conceived *) upon which the diameter of the drops of rain may be calculated, which Dr. Young finds to be between jth and 4th of an inch. By similar principles it is found that the supernumeraries of the secondary bow will be exterior to it and somewhat broader. 270. The darkness of the space between the primary and secondary bows is equally a consequence.of the common theory and the corrected one t. It is dark compared to the spaces containing the diffused lights (what Dr. Young calls the double lights, or duplicatures) corresponding to the respective bows. This darkness was described by Descartes§. The light of the primary and secondary bows]|, and also of the supernumeraries so far as observed, is polarized in the place of reflexion. 271. Mr. Airy has recently investigated fully the intensity of the light in the neighbourhood of a caustic formed by reflexion * Viz. for the observed deviation of the red ray in the spurious bow, find the angles of incidence and reflexion within the drop for the two rays which com- bine to produce it, and find the difference of the paths of the rays which corre- spond to this in terms of the radius of the drop. Reduce the difference of paths in water to that in air, and equating it to the length of a wave of red light, find the radius of the drop. Dr. Young hasindicated this process in his obscure but ableand comprehensive article Chromatics, in the Encyclopedia Britannica, with which Mr. Potter, who has recently written in support of Dr. Young’s views (Camb. Trans. vi. 141), appears not to have been acquainted. ¢ Philosophical Transactions, 1804, and Chromatics. { It is, however, very imperfectly or inaccurately explained in most popular treatises. Mr. Ainger has given a very detailed account of it in the Journal of the Royal Institution (Feb. 1831), in which he has added nothing material to what was shown by Dr. Young ; nor has he adverted to the cause of the super- numerary bows. § Brandes, art. Regenbogen, in Gehler, p. 1324. Kamtz, Meteorologie, iii. p- 158. It is very singular that neither of these authors seems to be aware of the true theory of the rainbow, or of Dr. Young’s writings on the subject. || First observed by Biot. See Annales de Chimie, xxxix. 430. q Arago, Annales de Chimie, ibid. SUPPLEMENTARY REPORT ON METEOROLOGY. 129 and refraction as in the rainbow*. Computing the intensities rigorously on the principles of the undulatory Theory of Light, he arrives by laborious numerical computations at the following results :— 1. The boundary of the caustic is not a mathematical line ; but the light shades off with extreme rapidity. 2. The radius of the primary bow does not coincide with the geometrical caustic deduced by the common theory. It lies within it at a distance depending on the size of the drops, and on the consequent separation of the interference fringes. 3. To find the radius of the geometrical bow from observation, “Add to the radius of the brightest observed bow 11 of the distance between it and the first supernumerary bow.” __ 4. Between the primary and the first supernumerary there is a space absolutely dark. 272. As several of these results differ quantitatively from those deducible by the simpler methods of Dr. Young, it is of importance to verify them experimentally. For the reasons already stated (264.), it is difficult to obtain satisfactory compa- rative measures from the natural rainbow. Much more deli- cate observations are obtained by an ingenious experiment de- vised by M. Babinet, of allowing a minute stream of water to flow through an opening #,th of an inch, or less, in diameter, and observing the deviation of rays proceeding from a small luminous body}. In this way Professor Miller, of Cambridge, has confirmed Mr. Airy’s result as to the deviation of the prin- cipal bow from the geometrical place of the caustict. 273. The existence and positions of the supernumerary bows and their dependence on the diameter of the refracting cylinder of fluid (and likewise on its index of refraction), have been shown by M. Babinet himself, who has observed no less than sixteen interior, and nine exterior supernumeraries, by means of a streamlet of water of the diameter above-mentioned §. 274. With acomparatively large (;4;ths of an inch) cylinder of glass he obtained the usual theoretical dimensions of a bow for the appropriate index of refraction. The supernumeraries were excluded by the size of the cylinders; but he obtained bows caused not only by one and two internal reflexions, but three and four, up to seven. These, the ternary, quaternary, &c. rainbows have been long theoretically known, though rarely, if ever, observed in nature. The ternary rainbow ought to occur * Camb. Trans. vi. 379. The abstract in the Phil. Mag., Third Series, vol. Xli. p. 452, is inaccurate. + Comptes Rendus, iv. 647. ¢ Phil. Mag., Third Series, vol. xiii. p- 10. This experiment was shown to me by Professor Challis. § Comptes Rendus, ut sup. VOL. 1x. 1840. K 130 REPORT—1840. about 41° from the sun, but is generally stated * to be too faint to be visible. Two observations by Bergmann are the only recorded ones I have met with}. Kamtz observed a ternary bow amidst the spray of the falls of Schaffhausen f. 275. We have said that the appearance of supernumerary bows indicates the presence of rain-drops below a certain size, as well as of considerable uniformity of dimension. It is re- markable that Langwith observed, more than a century ago, that “this effect depends upon some property which the drops retain whilst they are in the upper part of the air, but lose as they come lower down and are more mixed with one another.”’ M. Arago seems inclined to suppose, on the authority of d’Abbadie and the officers of the Venus §, that supernumerary bows are raret in equatorial climates than in ours. It should be recol- lected, however, that Bouguer saw them in South America with an unusual degree of vividness and separation|]._ M. Arago has recommended to the Academy of Sciences of Paris the execu- tion of a good coloured view of the rainbow, as a guide to ob- servers. C. Halos§ and Parhelia. 276. The apparent complication of the phznomena of halos and parhelia has given rise to a great deal of vague speculation and loose though ingenious theory. Observations of facts have been likewise wanting in precision. On these grounds, we will endeavour very briefly to discuss that part of the sub- ject which seems to have been most successfully dealt with, and endeavour to refer the explanations which have been given, to their proper authors; for so much has been written on the matter that the same thing has been produced as new by various writers at different times. 277. What would first be desirable would be a clear state- ment of what is to be considered a complete or normal example of the compound display of halos and parhelia. The phno- menon seen by Hevelius, at Danzig, 20th of February, 1661**, which has generally been considered as a characteristic exam- ple, consisted principally of— * By Young and Babinet. + Abhandlungen der Schwedischen Academie fiir 1759, p. 234. Quoted by Brandes. { Lehrbuch, iii. 160. § Annuaire, 1840, p.305. || Mém. de Paris, 1757, p. 60, quoted by Kamtz. § The halos now spoken of are the great halos of 223° and 46° radius, and have no reference to the small halos or coronz with which they are often con- founded, but which have a distinct origin. ** Tt is figured in almost every work on the subject. See Huyghens’s Op. Reliqua, ii. 38, and Fraunhofer in Schumacher’s Abhandlungen, Heft iii. ere SUPPLEMENTARY REPORT ON METEOROLOGY. 131 (1). Three halos round the sun, having Radii of 223°, 46°, and 90° nearly. The two smaller circles are generally coloured, the red being innermost. The circle of 90° is a rare appear- ance *, and is colourless. (2). A horizontal circle passing through the sun in which the parhelia or mock suns occur, usually at (or rather a little be- yond) the points where the halos intersect the horizontal (or parhelic) circle, and sometimes also in the point exactly opposite to the sun (anthelion). (3). Arcs of circles with reversed curvatures, touching the ha- los of 223° and 46° at their highest and lowest points. Mock suns sometimes appear also in the halos vertically above the true sun. 278. Even more complex phznomena are occasionally re- corded, as that observed at Petersburg, 29th of June, 1790, by Lowitzt. For a history of such appearances we must refer to Brandes’s article in Gehler’s Dictionary, Kamtz’s Meteorology, the article Meteorology in the Encyclopedia Metropolitana (with an excellent plate), Fraunhofer’s paper on the subject {, and to Dr. Young’s invaluable catalogue of references§. In the mean- time we proceed to the theory of the fundamental appearances. 279. In the 17th century Mariotte referred the halos of 224° to refraction through triangular prisms of ice. Minute icy spiculz being conceived to float through the air, or rather to de- scend slowly through it in all possible directions, a diffused re- fracted light must be seen, as is actually the case when the air is in this state; but those prisms which chance to be in a po- sition such as to refract the sun’s image to the eye in the posi- tion of minimum deviation, will (as in the rainbow, where the de- viation is a maximum) affect the eye more intensely on account of their parallelism and accumulation. The least deviated rays (the red) will fall upon the eye at the smallest angle with the sun, and consequently will form the smaller ring of the halo|. 280. Huyghens proposed a different theory 4], which for a time superseded that of Mariotte. He attributed the phenomena to refraction through spherical and cylindrical particles of hail having opake nuclei of determinate magnitudes. But the ar- bitrary nature of his hypothesis is contradicted by the constancy * In fact, the observation of Hevelius was unique in this respect until the circle of 90° was recently witnessed by Erman (see Poggendorff’s Annalen, 1840, xxxix. 255. note.). + Figured by Young (Lectures, i., plate xxix. fig. 483) and by Kamtz. ${ Schumacher’s Astron. Abhandlungen, iii. § Lectures, vol. ii. || Mariotte, Zuvres, 1686, quoted by Young. §| Huyghens, Phil. Trans., 1670, and Opera feliqua, ii. (Young). K 2 132 REPORT—1840. of the radii of the principal halos, which indicates a uniformity of cause incompatible with Huyghens’s assumption. The theory of Huyghens is alluded to by Newton, though without any ex- press approbation, at the close of his Theory of the Rainbow* ; and in another part of his Optics} the principle of refraction through ice-prisms of 58° or 60° is distinctly stated as the pro- bable cause of halos of 221°, which appears to have been New- ton’s own view, as he gives a reason for it (the oval form of some halost{), and does not quote Mariotte. 281. So little reason, then, is there for supporting Huyghens’s theory on the ground that it was maintained by Newton, as M. Biot has done §, even since Mariotte’s theory has been revived by Young, who published it in the second volume of the Royal Institution Journal||, where he states that he had adopted the principle before he knew of Mariotte’s application of it ; and he had even inferred from it that the refractive index of ice is less than that of water, a fact then doubted, but after- wards confirmed by Dr. Wollaston. M. Babinet has therefore no ground for affirming ** that M. Arago was the first to revive Mariotte’s explanation. 282. The most obvious facts in support of Mariotte’s theory of icy prisms are, (1). That the imperfect crystals of ice which alone we can obtain, have a tendency to rhombohedral crystallization, amongst the forms of which are three- and six-sided prisms ; and the minimum deviation of light through an ice-prism of 60° would give the halo of 223°. (2). The constancy of the effect gives a probability to a con- stant cause, such as a crystalline angle. (3). The fact that halos occur most frequently in cold cli- mates and after a sudden fall of temperature, when the moisture of the air is evidently and palpably deposited in icy spicule or hoar frost. In the excellent observations made in the United States, the relation between the sudden fall of the thermometer and the occurrence of halos is very clearly traced{}. * Optics, book i. part ii. prop. 9. + At the end of the second book. t It is rather singular that the same reason which was urged by Newton in favour of the theory of refraction by ice-prisms, should be stated by Arago (Annuaire, 1836, p. 8303; 1840, p. 303) as an anomaly which, on that theory, still requires explanation. It is plain that Newton had some theoretical opinion on the subject which he has not explained, and according to which the upper radius of the halo should be shorter than the lower. § Traité de Physique, iii. 476. || See his Lectures, ii. 306. q Ibid. ** Comptes Rendus, iv. 639. +t Annual reports made to the legislature by the Regents of the Universities of the State of New York. SUPPLEMENTARY REPORT ON METEOROLOGY. 133 (4). The important fact ascertained by M. Arago, that the light of halos is polarized by refraction and not by re- flexion *. 283. But other evidences arise from the application of the same principles to the phenomena which accompany the first halo, and many of which Mariotte pointed out so clearly as to supersede much which has since been written on the subject. 284. The halo of 46° may be ascribed to two refractions with the minimum deviation ti:rough two successive prisms of 63°, or as Cavendish supposes f, to the refracting angle of 90° formed by perpendicular terminations of the ice-prism. Such termina- tions, Dr. Young observes, are rather doubtful, and in his later writings { he inclines to the doctrine of successive refraction through two prisms. Fraunhofer § supposes pyramids with an- gles of 88° to be the cause; and he assigns as an explanation, which appears to him perfectly satisfactory, of Hevelius’s great circle of 90°, the limiting angle of total reflewion in six-sided prisms, which is 89° 56’. Hence this circle is white. 285. Parhelia«.—Mariotte accounted for this phenomenon by the preponderance of ice-prisms in a vertical direction (which he attributed to their being heavier at one end,—Dr. Young, more justly, to the resistance of the air ||), which therefore will form a brighter coloured image of the sun when the plane of re- fraction is horizontal than in any other plane. Mariotte had even the acuteness to see, that as the sun rose above the horizon, the plane of refraction being no longer accurately horizontal in order to reach the eye, the virtual refracting angle of these ver- tical prisms would necessarily be increased, and the deviation being greater, the parhelia would stand out beyond the limit of the halo, a fact remarkably coinciding with experience. Thus an officer of Sir Edward Parry’s Expedition§, observed par- helia distant 24° 40’ from the sun, the halo being at 22° 30). The parhelia are coloured, the red edge being nearest to the sun. 286. The horizontal or parhelic circle is not accounted for by Mariotte, because (he says) he had not an accurate descrip- tion of it. His commentator, Dr. Young, ascribes the horizon- * Bulletin Universel (Ferussac), 1825, Sci. Math. iii. 304. t Young, ut supra, } See the article Chromatics in the Encyclopedia Britannica. But the same doctrine is stated in his earliest papers, to which nothing of any consequence has been added in elucidation of this subject, except M. Arago’s important ob- servation of the plane of polarization. § Schumacher’s Abhandlungen, iii. 77. || Journal R. Inst. and Lectures, ii. 307 (1807). 1 Quoted in art. Meteorology, Encyclopedia Metropolitana, p. *169, 134 REPORT— 1840. tal circle to ‘‘ the reflexion or even the repeated refraction of the vertical facets*’’, an explanation which seems entirely satis- factory ; for though amorphous vertical fibres would produce the same effect (as Fraunhofer showed), yet it is much more natu- ral to ascribe the horizontal circle to the same cause with the parhelia which occur within it, and which are, in fact, merely its most notable points. Young attributes the mock suns occa- sionally observed at an elongation of about 142° to two refrac- tions and one reflexion in the same ice crystals+. 287. Fraunhofer, in his Memoir already cited{, ascribes the horizontal circle to the superposition of diffraction-spectra, which produce an excessively elongated image of a body viewed by reflexion from a striated surface, like that of glass smeared with grease, and then cleaned by rubbing it in one direction, when a whitish reflexion will take place perpendicular to the streaks. A similar view has been given more lately by M. Ba- binet §, who compares the horizontal reflexion to that observed from fibrous crystals, such as topaz and gypsum. 288. Contact-arches||.—The only remaining phenomenon which seems fairly accounted for, is that of inverted ares of lu- minous circles touching the halos, usually at their vertical dia- meter and accompanied by a parhelion, so that Dr. Young de- scribes it as “a bright parhelion immediately over the sun, with an appearance of wings cr horns diverging upwards from the parhelion.”’ This Dr. Young has ascribed with great inge- nuity and probability to very short triangular prisms, which from their flatness fall with their axes and refracting edges in a horizontal position, so that the plane of refraction is vertical. The abundance of such prisms (compared to those which fall obliquely and form the halo) give rise to the vertical parhelia (which Fraunhofer has, I think very unsatisfactorily, explained by diffraction**), Horizontal prisms parallel to the former, lying to the right or left of a vertical plane, passing through the observer and the sun, will evidently refract the solar image in a plane not perpendicular to the axis of the prism (because not vertical), and for which the refracting angle being greater, the so- lar image (formed always at the angle of minimum deviation,) will appear more elevated as the obliquity of refraction is greater, that is, as we proceed to the right or left from a line vertically above the sun. Dr. Young has confirmed his view by actual cal- culation Tf. * Lectures, i. 444. + Chromatics, sect. ii. paPasye § Comptes Rendus ; ut sup. || See art. 277. (3). “| Lect. ii. 807. col. i. See the figure of Hevelius’s halos, and others. ** Schumacher, wt supra, p. 78. tt Lect. ii. 308. col. i. SUPPLEMENTARY REPORT ON METEOROLOGY. — 135 289. Vertical lines passing through the sun and circles con- taining the sun in their circumference have also been described. The former seem to be independent of the existence of ice cry- stals; I shall therefore return to them presently. As to the lat- ter, we can only state generally, that from the wonderful com- plication which the figures of crystallized snow and hoar-frost take, we can conceive circumstances adapted to almost every degree of complication ; and such complication may be aptly illustrated by the curious figures which Sir D. Brewster has given of the wonderful variety of reflected figures observed at the surfaces of disintegrated crystals*. The same ingenious philosopher has illustrated the phenomena of halos by observing a distant light through alum crystallized rapidly on a plate of lass +. “ 290. M. Galle of the Berlin Observatory has lately published an elaborate paper on the subject of halos and parheliat, in which he gives a minute account of those observed by himself during nineteen months. Within this time he saw seventy-eight halos of 223°; of which only two were sensibly elliptical ; and he saw no halo of 46°. He afterwards gives at great length a general view of the theory of refraction by ice-prisms. 291. A remarkable parhelic appearance was observed by Lambert at Wetzler, in 1838, in which there were two hori- zontal circles at greater altitudes than the sun, but none passing through his disc. Besides the usual lateral parhelia there were four others at the points of contact and intersection of the halos of 223°, and 46° with the horizontal circles §. D. Corone: Glories, &c. 292. The coloured rings so frequently seen round the sun and moon when thin clouds pass over their discs, are carefully to be distinguished from true halos, as they may easily be, by the following characteristics, which evidently point to a wholly different origin :— * Edin. Trans., vol. xiv. plate x., &c. + Edin. Phil. Journal, viii. 394. This experiment, which has probably been oftener quoted than repeated, I have more than once attempted without success. t Poggendorff’s Annalen, 1840. xxxix. and 241. § L’ Institut, No. 321, Fev. 1840. M, Moigno, who quotes this description from Poggendorff’s Annalen, claims for M. Babinet the theory of the parhelic circle and vertical parhelia. These are, however, both due to Young; the only addition which, so far as I know, M. Babinet has made, is the very just remark that the horizontal circle will be brighter beyond the first halo than within it, because in the latter case the illumination is derived from reflexion only, by the vertical facets; in the former from refraction likewise. 136 REPORT—1840. (1). They are much smaller, their radii (when several series of their colours appear at once) being from 1° to 6°. (2). The radins of any ring is not constant at different times. (3). The red occupies the owter ring, instead of the inner one as in the true halo. 293. These coloured rings have a manifest analogy to those which bear Newton’s name ; and that great man, in his Optics*, has given an explanation, which, translated into modern lan- guage, would express the interference of the light reflected from the different parts of the drop. In June, 1692, he ob- served three rings or orders of colours round the sun of the diameters of 5° or 6°, 9°20! and 12°; on the 19th February, 1662 (so early had he begun to speculate on these subjects), be had observed the two inner corone round the moon to have di- ameters of 3° and 52°, little more than half the dimensions of the others. 294. The true explanation was unequivocally given by Young in 1802, in his paper “On some cases of the production of colours not hitherto described+,’’ amongst the consequences of the fertile principle of interferences, though in a different way from what Newton had imagined, or Jordan, who had attributed these colours to the inflection of light. Young had practically shown that the interposition of uniform strie or powder be- tween the eye and a luminous object produces coloured images of that object, depending for their position upon the dimensions of such striz or powder ; and he had theoretically given that beautiful explanation which was afterwards put in a more popular form by Fresnel and Fraunhofer. Yet it is remarkable, that the latter author (Fraunhofer), in describing the experi- ments on which he grounds the very same explanation of co- ronz, never mentions the name of Young. 295. The explanation in effect amounts to this,—that on the wave-theory of light, a luminous point is seen only in one direction, because the diverging wave produced propagates from its surface at any moment impulses which, when they reach the eye with any sensible obliquity, have their effect compensated by the opposite displacements caused by the ad- jacent portions of the wave. By the interposition of particles, opake or of a certain refractive power, and of nearly uniform size, portions of light become sensible in an oblique direction, by the stoppage of the other portions whose different length of path would have caused them to annihilate the action of the * Book ii. part iv. obs. 13. +t Philosophical Transactions, 1802. } Entstehung der Héfe kleiner, Art. Schumacher, Astr. Abhandl., iii. 56. SUPPLEMENTARY REPORT ON METEOROLOGY. 137 first. The angle of obliquity in which any light will reappear must depend upon the size of the opake particles; con- sequently, such coloured rings as this cause produces will vary with the size of the interposed globules of water or vapour, and will generally be larger as these are smaller. This was the principle of Dr. Young’s Eriometer for measuring the diameter of fibres and powders*. Thus Dr. Young has shown7, that a Corona, 8° in diameter, corresponds to the existence of drops (or spherules of any kind) 335; in diameter. 296. As might be expected, this dimension varies with the season. It appears, from the careful observations and compu- tations of Prof. Kamtzt{, that the diameter of the spherules is least in May, being then ‘00054 French inch; and greatest in January, when it is *00107 inch. This is one of the most certain data relative to the constitution of clouds. There seems no doubt that these are the “ Vesicles”’ observed by Saus- sure§. 297. The successive orders of colours recur at angular di- stances, nearly, or exactly, in arithmetical progression from the centre||. 298. Glories.—The well-known phenomenon of coloured rings surrounding the shadow of an observer thrown upon a cloud, has an evident analogy with the preceding one; and up to a certain point, the same explanation may apply. But there are peculiar difficulties connected with this appearance, which seem to be yet imperfectly resolved. 299. Bouguer observed in South America his shadow thrown on a cloud, and surrounded by coloured rings of 5° 20', 11°, and 17°, and a white ring of 67° in diameter]. Scoresby observed at sea a similar phenomenon on a thin stratum of fog. The rings had radii of 12° or 2°, 4° 45!, 6° 30!, and a whitish circle extending from 36° 50! to 42°. A larger and still fainter circle was once observed**. Professor Kamtz has seen on the Rigi similar circles of radius 37° 27' on one occasion, and 42° 10! on another, which he considers as true rainbows, very faintly tinged with red outside, and with blue within. At the same * Described in his Introduction to Medical Literature. ¢ Art. Chromatics, Encyc. Britt., Sect. xi. + Lehrbuch der Meteorologie, iii. 102. § See above, Art. (218) and note. || Young. Compare Herschel on Light, Art. 701. Fraunhofer, quoted by Kamtz, iii. 96. Babinet, Comptes Rendus, iv. 643. | Mémoires del’ Académie des Sciences, 1744, 4to edit., p. 264. Each man saw only his own shadow; but the reason assigned is not very clear. ‘“ Chacun de nous vit son ombre projetée dessus (i. e. on the cloud), et ne voyait que la sienne, parceque le nuage n’offroit pas une surface unie.” ** Kamiz, ili. 108. 138 REPORT— 1840. station I have seen a single compound circle, of which the red ring had a diameter of 18°; but when I entered the cloud on the surface of which it had been formed, it contracted to about 10°. In the Jura Mountains I once perceived traces of a faint ring of from 75° to 80° in diameter.* 300. Accompanying the coloured rings, there is an appear- ance of white light, more intense towards the centre (corre- sponding to the prolongation of a line drawn through the sun and the eye of the spectator), which would give evidently the brightest illumination in the middle point, but for the shadow of the observer’s head, which, however, is wonderfully di- minished by the nebulous light. 301. That crystals of ice should have anything to do with these appearances, as conjectured by Bouguer and Scoresby, is altogether incompatible with the circumstances under which other observers have seen them. It is equally impossible to refer these rings to the diffraction of the solar light falling upon particles of vapour surrounding the observer's head, as Fraunhofer supposed, and reflected back to his eye from the surface of the cloud; for I have observed these rings distinctly from a height of fifteen hundred feet above the cloudy screen, under a brilliant sky. But the common theory of diffraction of particles reflecting as well as stopping light, affords a plausible account of some of the phenomena. We have only to suppose the constituent materials of the cloud to be spherules (however composed) of nearly equal size which reflect innumerable images of the sun from their surfaces, backwards to the eye. Some of these must be placed at distances which shall re-inforce each other’s effect, and some which shall annihilate that effect ; and hence periodic colours will result, as in transmitted light (the case of corona). 302. This opinion is confirmed (1) by the order of colours being that of diffraction rings (the red outermost); (2) by the arithmetical progression of the diameters observed by Bouguer and Scoresby; (3) by the curious fact noticed by myself, that on immersion in the cloud the rings suddenly shrink in size (due, no doubt, to an increase in the magnitude of the cloudy particles in the interior); (4) from the comparison made by Professor Kamtz, between the diameter of the Corona by * Haygarth, in the Manchester Memoirs (Ist Series, iii.), gives rather an unsatisfactory account of a glory which must have resembled those seen by Bouguer and others. The greatest faint circle at a distance from the smaller ones, is distinctly shown in the bad plate which accompanies the paper. + Schumacher, Abhandl., iii. 63. SUPPLEMENTARY REPORT ON METEOROLOGY. 139 Transmission, and the Corona by Reflexion, the same stratum of cloud forming both; and he obtains in general a satisfactory coincidence* ; (5) by the curious observation of M. Babinett, of similar rings formed round the shadow formed on the minute particles of gunpowder which had been laid out to dry. 303. On the other hand, it is not consistent with what we know of such phenomena, that the third ring (for instance), that having a diameter of 18°, should be seen so vividly, and sometimes to the exclusion of any other (for it is hardly likely that so large a ring should be one of the first or second order). The great rings of 67° to 84° in diameter, can scarcely be thus explained. 304. Dr. Young seems to have felt the full difficulty of the subject of reflected glories ; and he has unfortunately expressed himself very obscurely upon it. In his earlier writingsf, he contented himself with referring them to the colours of thin plates ; but afterwards he seems to have hesitated whether to consider them as modifications of the corona (by diffraction), or of the rainbow. In his article, “‘ Chromatics §,’’ he has given a singularly perplexed theory, which we have read over many times without clearly understanding ; the reasoning, however, appears to be this :—Supposing a cloud to be formed of drops of water, light, four times reflected within such drops, will furnish rays which will unite in the same phase from both sides of the drop, at a point diametrically opposite to the sun, whilst rays (also four times reflected) ultimately coinciding in direction, and which have undergone reflexion at smaller and greater angles, will unite in different phases, the retardation being nearly as the angular distance from the central point. It is to these supernumerary bows of the fourth order, that he ap- pears to attribute the inner circles, whose diameters were, in the observation of Bouguer, 6°, 11°, and 17°. 305. Having found the size of the drops which would give, by diffraction, rings of this description ||, he proceeds to find the distribution of the colours of a primary rainbow formed by such excessively minute drops (less than z,45 inch). He assigns to the first supernumerary red bow a radius of 24°, of which, however, he inakes nouse. He then observes, that owing to the minute size of the drops, the shading off of the primary colours is very slow on the concave side, so that the red will sensibly oc- cupy a breadth of 73°, the violet of 53°; and as the red and * Meteorologie, iii. 111. t Comptes Rendus, iv. 645. t Lectures, ii. p. 645. col. i. § Encyc. Britt., seventh edit., p. 638. col. i. || Computed, however, for a radius of 5° for the first ring; whereas, in Bouguer’s observation, the diameter was 5° 20!. 140 REPORT—1840. violet arcs are already 2° apart, they will overlap, and form a whitish ring, whose radius will be that of the red ring of the rainbow, or 42°, diminished by 73°, leaving about 35° for the radius of the whitish ring, agreeing sufficiently well with ob- servation. 306. I apprehend, however, that there are many difficulties in this view of the subject. That light, four times reflected, should have intensity enough to produce three or more coronez, seems incredible. Again, the ring of 37° to 42° radius, ob- served by Kamtz and Scoresby, with faint colours, seems to be the rainbow itself, not the superposition of its faded colours, for Dr. Young very obscurely hints* as to the non-appearance of the real bow. The reason of its variable magnitude and faint colour is quite sufficiently explained by Mr. Airy’s in- vestigation (271.), in which the deviation of the maximum of in- tensity from the geometrical caustic is shown to depend upon the size of the drops, and that diminution of size diminishes the radius of the bow, and likewise the sharpness of its definition, though in every case (as it seems to us) the maximum next the caustic must be most intense, and therefore the true bow can never vanish so long as any of its subordinate features remain, which Dr. Young seems to have thought possible. Finally, Dr. Young, in another section of the paper so often referred tot, adopts the theory of diffraction as producing the lesser glories, and calculates the size of the drops on that hypothesis, which size is double that obtained on the other. : 307. Had not this discussion been already extended further than persons more interested in meteorology than in physical optics may think suitable, I should have dwelt at some length upon certain curious phenomena of shadows with luminous borders, and certain vertical trains of light seen in connexion with them, which seem not to have received the attention which their theoretical importance demands. I wil] state very briefly what may serve to instigate further inquiry. 308. Standing on the tower of Carisbrook Castle with a friend one calm hazy summer evening near sunset, I perceived glori- fied shadows as from the Rigi, but without colours. So intense was the concentration of rays opposite the sun, that the shadow of the head of the observer was almost obliterated by the inten- sity of the light which seemed to emanate from it. The shadow of the body was fringed all round by a luminous but colourless border. The shadow of another person standing a short way * Chromatics, p. 625, col. i.; p. 638, col. 1. + Chromatics, Sect. xi. EE EEE a ee eee eee SUPPLEMENTARY REPORT ON METEOROLOGY. 14] off presented to the first observer nothing peculiar. The lumi- nous haze extended but a short way right and left, but in a ver- tical direction it extended through a very considerable angle, producing the very singular effect of a train of hazy light. The same effects I have seen less perfectly in other localities, but generally towards sunset, and only when a considerable space intervened between the observer and his shadow. 309. Similar phenomena have been described by various ob- servers, and variously accounted for*. The vertical train of light which occasionally accompanies halos, has been explained by the reflexion from the bases of vertical crystals;; but as it is seen to occur in circumstances such as those mentioned in the last paragraph, it must evidently be independent of the existence of ice in the air. Fraunhofer has endeavoured to explain it on principles of diffraction, and I conceive that it is most likely to be explained on some such principle, taking into account the abrupt variations of temperature which often take place near the ground towards sunset, and which produce strata of air very variously charged with moisture in various degrees of con- densation, horizontally disposed, and partial reflexion in which would undoubtedly tend to produce a diifuse vertical image, such as we see on water slightly rippled, when looking across the rippled surface. The main cause, however, of this expanded vertical image appears to be, that by looking very obliquely through a thin stratum of cloudy particles, their apparent di- stances will be diminished by the obliquity, and their interstices in the same proportion. Diffraction bands will, therefore, ex- pand in the direction in which the particles are apparently compressed. I have found that such phenomena are accurately reproduced by suffering soap-suds to dry upon a plate of glass, and then looking at a flame obliquely through it: when viewed perpendicularly neither colour nor diffused light appears in one direction more than another. 310. The occurrence of the anthelion itself, or luminous point opposite the sun, is not of so easy explanation as some writers seem to consider it ; and until it is fully understood, we can hardly hope to explain all its modifications. The glory * See the observations of Hevelius, Derham and Young, quoted in Young’s Lectures, ii. 303, as to the vertical train of light; more lately by Mr. Christie, British Association, 7th Report, Sections, p.15. [Mr. Christie’s original commu- nication to the Meeting at Cambridge in 1833, contained in a letter to me, appears to have fallen aside, and is neither published nor in my possession. ] ¢ First by Young, also by Babinet (Comptes Rendus, iv. 640), Galle (Pogg. xxix. 256), and others. ¢ Schumacher, Abhandl., iii. 82. 142 REPORT—1840. observed round the head on dewy grass * is evidently referrible to the reflexion from spherical drops at no great distance from one another. The peculiar luminous fringes observed round the whole shadow (308.), I have assured myself by many trials to arise from no optical deception. There is a space close to the shadow, and following its boundary, more luminous than the fully enlightened space beyond,—a fact which it seems not easy to explain. It appears to have no reference to the nature of the body (as, whether it is bedewed or not) which yields the shadow; nor is it altogether dependent on the body which acts as the recipient screen, but it depends chiefly, I ap- prehend, on the condition of the strata of air very near the ground. We must consider it, I suppose, as an effect of dif- fraction, such as would, in point of fact, be seen where the shadow of a body is thrown upon a screen by a single radiant point at a certain distance ; in this case, however, it is not the smallness of the luminous body, but the cluster of minute globules which reflect small images of the sun that are the cause of the diffraction ; the effect being to produce a luminous band, succeeded by a darker one whose contrast renders it more visi- ble. The effect is no doubt enhanced by the indeterminateness of the surface which reflects these little images. The shadow is seen through the whole depth of the nearly invisible cloud, and the bounding surface of light and shade will be most pro- minently seen when the eye is in a position to follow its course in the interior of the mist. 311. The phenomenon described by Professor Necker}, of the intense illumination of shrubs and trees forming the horizon behind which the sun has just set, is, I conceive, a precisely parallel fact; and M. Babinet t has explained it in a similar manner. But there is still something in this as an optical phe- nomenon which seems to me to require further investigation. 312. It should not be forgotten, with reference to the phzno- mena of clouds, that they have been treated by Young and others on the hypothesis of their being composed of spherical drops of water. Bouguer, Kamtz and Fraunhofer, maintain their vesi- cular structure ; and the last-named author has in his Memoir, so often cited, considered minutely the course of a ray of light through a spherical watery shell. The great modification which the common rainbow undergoes in a cloud, and the rarity of its * Garthe, dbhandlung tiber den Heiligenschein : quoted by Kiémtz, iii. 106. and other authorities there mentioned. t+ Philosophical Magazine, Third Series, i. 332, where two diagrams repre- sent the fact very well, as I remember to have seen it under Professor Necker’s directions. t Comptes Rendus, iv. 644. SUPPLEMENTARY REPORT ON METEOROLOGY. 143 occurrence, seems, to say the least, to give some plausibility to the latter opinion. X. SUGGESTIONS. 313. In conclusion of this report, I propose to offer a few suggestions more definite than I have yet given for the advance- ment of meteorological science. I have glanced at various ques- tions which require elucidation, and which fall within the scope of science in its present state; but amore systematic recapitula- tion of some of these will place them more intelligibly before the reader. 314. It has long been matter of regret, that the labour which every one knows is spent on meteorological inquiries, should be so ill-directed ; but this it is easier to regret than to remedy. It is discouraging to be obliged to declare that meteorological ob- servations, to be of any value, are not so easy as is commonly supposed, and that not only perseverance but intelligence is generally speaking necessary to make such observations as are useful to science. Many registers, however well kept and or- ganized, are redundant; many would be useful were the results reduced and corrected ; many may have a local value, though they do not greatly advance the general progress of science. 315. For the sake of precision I will combine what I have to say under three heads, (1) On Public Observatories, (2) On Private Sedentary Observations, (3) Suggestions to Travellers. A. Public Observatories. 316. It is of little use complaining of the past neglect of me- teorological observations in astronomical observatories. Some attempt is now being made to combine with them a system of meteorological observation, or what is better, to institute mag- netical, meteorological, and generally, physical observatories. The vast sums of money which have been spent in doing over again what has been better done elsewhere in determining as- tronomical data, might have almost created new sciences of ob- servation. 317. The meteorological observations at Paris deserve par- ticular notice, as having been conducted upon a simple and re- gular system, for a considerable series of years. The barometer and thermometer (which, I believe, are kept in good order) are registered four times a day—at 9 a.m., Noon, 3 P.M., 9 P.M., hours evidently selected for the barometic oscillation*. At Brus- sels the barometer, thermometer, hair hygrometer, wind, and * Published in the Annales de Chimie and Comptes Rendus. - 144 REPORT— 1840. state of sky, are registered at 9, Noon, 4, and 9*. At Marseilles a very elaborate register is kept every three hours (I believe) of the day and night, under the watchful superintendence of M. Valz+. At St. Petersburg and other stations of the Russian empire, meteorological and magnetical observations are made eight times a day—viz. at 8,10 a.m., Noon, 2, 4, 6, 8, 10 p.m.f 318. Observations are regularly made at the Milanese Ob- servatory, Palazzo Brera, at 0, 3, 6,9, 12, 18, 21 hours astrono- mical time, and are published in the Biblioteca Italiana. We learn from an article in the Bibliotheque Universelle§, that ex- tensive meteorological observations by Sig. Colla, at Parma, are published, under the title of Giornale Astronomico. Farther, it appears, that at the late meeting at Pisa, it was agreed, on the motion of Sig. Antinori, to concert measures for contemporane- ous and comparable observations throughout Italy|. 319. The observations conducted at the various academies of the Stateof New York, and published annually hy the legislature, are still continued on a uniform plan, and must be productive of considerable benefit to science. Near the equator, at Trevan- . drum, in the Kast Indies, an admirable meteorological register is kept, under the direction of Mr. Caldecott, astronomer to the Rajah of Travancure. During his recent stay in this country, Mr. Caldecott has made arrangements for extending considerably the range of his experiments and observations. 320. The observatories fitted out under the direction of the British Government and East India Coinpany, combine meteor- ological with magnetic observations every two hours of the day and night{. It is matter of regret (though it is to be hoped the regret is a temporary one) that whilst these admirable means of observation have been sent to both hemispheres, and to the Antipodes, none have been established at home**. Iam not aware that there is a meteorological register which can be called au- thentic (in respect of the three following qualifications) conduct- ed in any part of the British Islands. 321. The special objects of public observatories would seem to be— * Published in 4to by M. Quetelet. + Unfortunately it is not published. + Published under the direction of M. Kupffer. § For August 1840. || Atti degli Scienzati Italiani, p. 30. Sig. Cacciatore’s observations have been already referred to (11). q Forms of Register are prepared by the Royal Society. ** Since this was written I am glad to learn from Mr. Airy that arrangements have been made, by which an authentic Meteorological Register will be com- bined with the Astronomical and Magnetical Observations at Greenwich. SUPPLEMENTARY REPORT ON METEOROLOGY. 145 (1). To furnish standards of comparison ; (2). To establish the laws of phenomena ; (3). To fix secular, or normal data. The second of these determinations may be made without the first and third, and conversely ; just as in magnetism one set of instruments serve to measure variations of elements, which yet are incapable of establishing the fundamental values of the ele- ments themselves. 322. In respect to the First point, the instruments must not only be originally good, but they must be preserved in constant repair,—a matter requiring perpetual revision in the case of meteorology. Access, under due regulation, should be permit- ted to instrument makers and observers to have their instruments compared with the standards*. That the instruments be abso- lutely as well as relatively correct, is evidently essential to the determination of the mean pressure at the level of the seat, the actual state of climate with respect to temperature, &c. 323. Secondly.—Thelaws of phenomena can usually be only made out by extended and minute observation, incompatible, generally speaking, with private research. Laws of a certain de- gree of generality have commonly a pretty wide domination, even in a science apparently so capricious as meteorology. The in- stance we have mentioned of the “‘ homonymous hours” (37.), representing the mean temperature of the day, is one of the kind: the constancy of the interval between the hours of mean tempe- rature is another: the mean of diurnal extremes being nearly the mean temperature of the day is a third : the nearly coincident hours of diurnal barometric variation is another :—these, and such laws deduced from sufficient data, clear the way for indi- vidual exertion, and indeed form the only basis for really useful efforts of the kind. A very small number of observatories (comparatively), perhaps three or four in the extent of the Bri- tish islands, would be sufficient to supply these important data. The observations must be made every two hours at least, for with less than this the diurnal curve could not be properly drawn. But such laborious observations would not require to be indefi- nitely continued. Once place the meteorological observations on a proper footing, by ten, or perhaps twenty years’ observation of this kind, and the great difficulty is overcome: there is not a chance of secular changes sensibly affecting these laws; once established, they are like the laws of the solar system. * As is done, for instance, at Paris. + The specific gravity of the mercury should be actually ascertained, and the pressure might be stated in the corresponding height of a column of distilled water at a fixed temperature. 1840. L 146 REPORT—1840. 324. Directions would thus be obtained for prosecuting, under the most favourable circumstances, and at the least possible ex~- pense of labour, all inquiries as to ocal climate in observatories of the second class, and by private individuals. In such ob- servatories, observations might be made twice or thrice a-day, and some even seldomer. The regular observations at public observatories should include the following :— Thermometer, barometer and moistened bulb hygrometer, at least every second hour. Wind may be registered by Whewell’s and Osler’s gauges. The state of the sky may be frequently noted. Rain by Osler’s gauge; other rain-gauges at three vertical stations. Temperature of the earth from the szface down to twenty- four French feet. The shorter thermometers must be ob- served at different hours of the day; the longest once a week. Temperature of the earth at a considerable depth in caverns, wells, or Artesian bores. The thermometers (generally) should have their zero verified from time to time (twice a year). Solar radiation by the actinometer. Nocturnal radiation. Atmospheric electricity and the aurora borealis, with cor- responding magnetic observations. Falling stars, especially in August and November. Other occasional phenomena, of course, will be recorded. Experiments, by means of balloons, on the decrement of temperature above the soil. 325. It would not be too much to expect that the directors of the first class of observatories should be capable of forming a judgement on the great cosmical questions of meteorology (ad- verted to in the section of this report on terrestrial tempera- ture,) and of uniting theoretical and practical knowledge to the important end of obtaining tangible and useful solutions of these great problems. For this purpose, it would be necessary not only to institute observations, but experiments; and, by the trial of many independent plans, to estimate the confidence due to the various methods in so delicate a research. By ascer- taining exactly what data may be obtained a posteriori, a definite problem may then be given to mathematicians to resolve; and we shall then know, and not till then, what investigations are to be regarded as merely speculative, and what of any substantive value. 326. Thirdly.—The laws of phenomena being known by such a limited course of elaborate experiment as has been recom- SUPPLEMENTARY REPORT ON METEOROLOGY. 147 mended, the next business connected with a public observa- tory is to furnish the secular constants of meteorology, such as the mean annual temperature, the mean annual pressure at the level of the sea, the limits of variation of these, the mean ela- sticity of vapour, the mean and total quantity of sunshine, the mean direction and integral quantity of wind, and similar facts, for a given place at a given time. These observa- tions are of a less elaborate kind than the preceding ; but the fate of all volunteer experiments shows, that to determine such quantities with minute precision, is incompatible with any but an official system of registration, which shall be conducted for very many years on exactly the same system, with instruments of the same kind, with unremitting attention not only to the fidelity of the observations, but to the perfect repair and com- parability of the instruments. Even should such a system not be started on the very best possible plan, it is better that it should continue uniform, than undergo perpetual change. If the hours or locality be not the best possible, the diurnal laws being known, the result of any hour may be converted into a mean result; and as to locality, it is much more important to preserve the consistency of results, than to avoid trifling disadvantages. 327. We have seen that it requires very many years’ observa- tions to ascertain the mean climateric state of any point of the earth’s surface. In this country, for no one such point probably is it accurately known. Let the instruments be the simplest, but the best; the observations, however few, perfectly regular; and we have a certainty that we are laying up valuable facts at least for another generation, if not for the present one. 328. Instead of labouring to collect a multiplicity of imper- fect registers, let us begin by laying the foundation of a rational and accurate science. If we can but determine accurately the secular elements of pressure and temperature at a hundred well- chosen points of the earth’s surface, we shall do more than has ever yet been done to draw a proper system of isothermal and isobarometric lines, which shall hand down to posterity the actual mean condition of our globe. 329. Observations must not only be made, but they must be wholly reduced and printed, like the astronomical observations conducted by Mr. Airy*. They must be ready to be applied to the purposes of science, and synoptic tables of results widely distributed. In the deduction of Laws from Results, much use- less labour may be spared (and the remark is especially appli- cable to private observers), by employing graphical projections * For this purpose excellent printed forms have been supplied to the Ant- arctic expedition. L2 148 REPORT—1840. instead of elaborate formule of interpolation, a method which, however valuable in itself, has been carried to excess by the German meteorologists ; and the immense labour they have spent in computing arbitrary constants might, in many cases, have been better bestowed. Anything, however, is better than no reduction at all. The engraving of such charts is well worth doing ; they often afford a check upon the accuracy of the ob- servation, the value of the method, and the consistency of the results, which no other mode of exhibition can possibly do. 330. I would notice the projection of observations on sub- terranean temperature (96), as a signal instance of all the advantages which I have mentioned. Where several simul- taneous but independent observations are made, the comparison, by projection, gives a moral certainty of the fidelity of the ob- servations, whilst the coincidence of one year’s observations with another demonstrates the confidence due to the method of investigation even more satisfactorily than the coincidence of final results. Even in point of accuracy, the maxima and minima cannot be so well determined by a parabolic interpola- tion (as M. Quetelet has done), because the temperature -curves invariably rise faster than they full; consequently, the oscu- lating parabola has not its axis vertical, but inclined to the left upwards ; and if a series of circular functions be used to ex- press the observations, the computation becomes very laborious, and perhaps the result is not more accurate than may be ob- tained in a few minutes in the following way.—A thin stiff wire may, by a little practice, be adapted so as to follow, in a remarkable manner, the sinuosities of the temperature-curves : by changing its form by pinching, then bending it elastically, and varying the inclination of its symmetric axis with the verti- cal, it is easy to lay it so over the curve*, as to satisfy the eye that the inequalities on each side compensate one another. 331. Until national observatories shall be formed, it seems of great consequence that the Plymouth Hourly Observations, made at the expense of the Association, should by no means be discontinued ; that the results, amply reduced, perhaps the detailed observations, should be printed at their expense ; and most particularly, that the condition of the instruments shall be from time to time verified with the utmost care, in order to render these determinations positively as well as relatively ac- curate, for which I do not know whether there is at present any sufficient security. * Or polygon; for in all cases, the actual points of observation should be joined by straight lines. This suggestion I owe to Mr. Babbage, and I have found it attended with great advantage. SUPPLEMENTARY REPORT ON METEOROLOGY. 149 B. Sedentary Observations. 332. Private individuals, fond of science, would find the establishment of such systematic observatories as we have recommended, to add great importance as well as interest to their labours. 333. Their business would then be like that of detailed sur- veying after the great net-work of triangulation has been com- pleted. The local meteorology of a country is often of great practical as well as scientific importance, and the immense dif- ference of climate frequently experienced within a few miles, whilst it shows the embarrassing effect of local causes, and the danger of drawing general conclusions from insulated or im- perfect registers, is itself a curious subject of research. 334. Ordinary thermometrical and barometrical registers may be continued, as has been usual, with additional attention to the construction and repair of instruments, the choice of situa- tion, and the choice of hours. In respect of the latter, 9 a.m. and 9 p.M. are very convenient and fitting hours for thermo- metric observations, to which may be added 3 or 4 P.M. for the sake of the barometric oscillation. But it is one advantage of systematic observation, such as was recommended in the last section, that it will render available observations made else- where at any hour or hours by a general principle of reduction to the mean*. Self-registering instruments (thermometers, rain-gauges, anemometers, and the like) are well adapted for private observation from the little superintendence they require. 335. I would, however, particularly urge the propriety of not confining individual efforts to the mere multiplication of simple registers. The same expenditure of time and money is appli- cable to much more interesting purposes. Special series of observations and experiments on one or more subjects, such as the following, would be of very great interest indeed :— 1, The temperature of the soil at small depths. If the dif- ficulty of procuring long thermometers be an objection, water-bottles may be lowered to different depths in sepa- rate tubes of wood sunk in a well, which is then filled up with earth or sand, and the temperature may be noted by a common thermometer on pulling them up, the opening of the tubes being well stuffed with hay or woolt. (98.) * As was clearly pointed out by Sir D. Brewster, in discussing the Leith hourly observations. It must be remembered that such reductions are correct only within the limits of the region or climate for which they have been ascertained. + A not unimportant modification of these experiments might be made by covering a certain space of the surface of the soil in which the thermometers were sunk, with a composition of ascertained radiating and absorptive power. 150 2. 3. 4, 5. REPORT—1840. Temperature of mines, galleries, deep wells, overflowing or Artesian wells, rivers at various distances from their source and from glaciers; the sea and lakes at different depths and seasons. Modifications of temperature, + or — immediately above the surface of the soil at different hours and seasons. (60.) Decrement of temperature at different heights, and the modification of the annual and diurnal curves due to ele- vation. (51, 57.) A comparison of the different instruments for measuring solar radiation—Leslie’s, Cumming’s, Herschel’s, Pou- illet’s. (61, &c.) 6. Observations on nocturnal radiation in different states of the atmosphere, and towards different regions of the heavens (at the same angular elevation) ; comparison of the ethrioscope (especially the effect of metallic reflectors in increasing cold, questioned by Pouillet); Pouillet’s actinometer ; the thermo-multiplier. (79, 80, 114.) 7. The ascertainment, by barometric measurement, of the elevation of a number of marked points in the neighbour- hood of the observer’s residence. A combination of such local results would give the general configuration of a country. The levelling (by the barometer) of the course of rivers, and a few of the most elevated points of the in- tervening mountain-chains, is most useful*. 8. The relation of the boiling points of fluids, especially water and alcohol, to the barometer, and the supposed anomalies mentioned by Hugi. (163.) 9. The curious anomalies in barometric measurements de- pending on the difference of temperature of the two stations (Lenz and Galle), and perhaps on the direction of the wind. (159.) This is an important, and, in a favourable situation, not a difficult inquiry T. 10. Further comparisons of the dew-point and moist-bulb hygrometer are not necessary. But careful observations with the latter are highly desirable under all possible cir- cumstances. The curves of annual and daily dryness ought to be investigated, and the indications of the instru- ment reduced, not by the computation of the correspond- ing dew-point, but by ascertaining (from Apjohn’s for- * See M. Guerin’s very interesting Mesures Barométriques dans les Alpes Francaises, Avignon, 1829. An excellent specimen of what is here intended is to be found in the Comte de Raffetot’s barometric measurements in the valley of Baréges. See Edinburgh Philosophical Journal, January, 1837. + Ramond’s Mémoires sur la Formule Barométrique cited in the former Re- port may be consulted with advantage on this subject. SUPPLEMENTARY REPORT ON METEOROLOGY. 151 mula, (175, 180)), the absolute and relative dryness of the air, 7.e. the tension of vapour and the ratio to saturation. Experiments would still be desirable to ascertain the effect of a current of air in modifying the indications of the moistened thermometer. 11. To pursue experiments on rain-gauges at three stations vertically above one another, (221) combined with hy- grometric observations. 12. To deduce from phenomena proofs of the revolving or radiating character of storms, or of the existence of both kinds*. (212, &c.) 13. To multiply observations upon meteors, especially in August and November. For this purpose, nothing more is requisite than the combination of several intelligent observers, who should select particular portions of the heavens for observation, having acquired, by the aid of a globe or planisphere a sufficient knowledge of the con- stellations, and who, being each provided with chro- nometers, should note, (1) the time of appearance; (2) the duration of the meteor; (3) its magnitude and phy- sical peculiarities ; (4) its direction and velocity of motion. 14, From what has been said on the subject of atmospheric electricity, it will appear that almost everything remains to be done on that subject; he who proposes to enter on the field must be prepared to cope with the difficulties of original investigation. 15. Auroral phenomena. The division of them into classes (if possible), of which probably the height, nature, and magnetic effects may be very different. 16. Many of the departments of optical meteorology are well fitted for Sedentary Observation. See the particulars spe- cified in the next section. C. Travelling Observations. 336. A traveller is placed in circumstances so eminently fa- vourable for arriving at just conclusions in meteorology and other similarly-conditioned sciences, that he cannot be too frequently reminded of the responsibility which attaches to his situation. All men who have cultivated the valuable art of viewing intel- ligently what passes around them, may arrive at important de- ductions from the observations of the most monotonous and most * Observations of great value may be very simply made by noting the periods of sudden rise of wind, and especially the times when its direction changes most rapidly, and the nature of the change. Barometrical observations add to the value of these recorded facts. 152 REPORT—1840. sedentary life ; but he whose choice or opportunity carries him through many climates and varying circumstances, cannot too zealously watch the occasion of discovering processes which only a happy accident may reveal, and of profiting by the com- parison and contrast of phenomena. Every one knows how indolence and indifference steal upon the mind long habituated to a daily-shifting scene, and how apt opportunities are to be lost through weariness or inattention. The traveller would do well, therefore, to entertain some preliminary considerations as to the sort of observation suited to his peculiar position. Sy- stematic observations are, toa great extent, beyond his reach ; and regular meteorological journals, kept from day to day under continually varying circumstances, are of much less value than those made in one spot, so that such registers may very gene- rally be abandoned, unless in the case of visiting peculiar or little-known climates, where any sort of approximation to sy- stematic observation is valuable. 337. There are, however, certain phenomena which afford such definite conclusions within the range of a few or even of single observations, as ought especially to engage the traveller’s attention ; such, for instance, as 1. The temperature of the superficial soil between the tropics, which, as already stated (128, note), is generally constant at one foot deep, and represents the annual mean. Intimately connected with this is the important general question whether the superficial earth temperature coincides generally with that of the air, which is yet undecided. 2. The temperature of springs, deep wells, and mines. (117, &c.) The elevation of these above the sea should be determined barometrically or otherwise. Where several springs rise near one another, the temperature of severa/ should be recorded. It does not by any means follow, that the largest springs always give the best results. 3. Particular attention should be paid to those springs which appear to have a temperature above or below that of the air at the place. In the case of very hot springs it is very interesting to repeat the observation with the same ther- mometer or instruments which have been compared, in different seasons and years*. (131.) * Having been requested some years ago to draw up instructions for obser- ving springs, I may, in the hope of attracting additional attention to the subject, introduce them here, not having been elsewhere published. HINTS FOR OBSERVATIONS OF THE TEMPERATURE OF HOT SPRINGS. The thermometer used in fixing the temperatures should be originally good, and should besides have its freezing point verified occasionally by plunging it in melting snow. Fractions of degrees should be estimated at least to one-fourth, SUPPLEMENTARY REPORT ON METEOROLOGY. 153 4. Meteorological extremes have always a certain interest which makes them worthy of preservation, whether they be if practicable, to one-tenth, If possible one person should note the results at the instant that the other observes, and to avoid errors the observers should then change places. ‘The stem of the thermometer should be immersed in the water, so that the whole mercurial column may be of the same temperature ; it should be kept there until the reading becomes quite stationary, and the read- ing made whilst so immersed. Hot springs are either uninclosed, or applied to the supply of baths, &c. In the former case great care must be taken in marking distinctly the locality, as springs often occur so near to one another that confusion readily arises: the bearings of any permanent objects near should be given, and the popular name of the spring, if it have one. If the spring be collected (as is usually the case) from a number of imperceptible sources, the fact should be mentioned and the hottest part taken. In the case of the supply of baths, too great care in reaching the real sources cannot be enjoined. ‘The servants of the baths are often ignorant of the true springs, and are unable or unwilling (because they are difficult of access) to point them out. When the real source cannot be reached (from being underground or built up) the nearest bath cock should be tried, having been first opened for some time, and the observer should record the number of the cock, its distance from the spring, and the nature of the con- duit, as well as give an eye-sketch of their relative positions. Where the wa- ter is stopped in its passage by reservoirs, these should be especially noticed, as they render the observation of temperature of little value. Often the spring rises over a great extent of surface into a large piscina or public bath. {n this case the observation is generally unsatisfactory, but the temperature of different points of the basin should be ascertained and the hottest recorded. If gas rises it should be ascertained whether its temperature differs from that of the water. The traveller should repeat his experiment on different days and at different hours, and at as great an interval of time as his stay permits. As many springs as possible (of those which are really independent) should be observed, and to prevent mistakes as to the independence and purity of the springs (for those more esteemed are often mixed with others of inferior quality) the best author- ity (usually the resident physician) should at once be consulted. With a view to comparison with former observers, changes in the management of the reser- voirs, &c., should be inquired for, and their date noticed. No ordinary traveller can undertake an analysis of mineral water, but if the spring be employed medicinally he may probably obtain some information from the resident physician or druggist, which should be preserved (with the authority). He may further, after a little experience, judge (by taste and smell) to what class of springs it is referible, as sulphureous, alkaline, saline, chaly- beate or acidulous. The easier experiments which he might further make would relate to the specific gravity of the water, and to the nature of the gas evolved, which is a very important question. There are cases in which it might be desirable to preserve, well corked, a portion of the water for analysis, but such are comparatively rare. Historical and other information may often be got from physicians and in- telligent proprietors of baths. Such persons might sometimes be induced to undertake observations every week or month on the precise variations of temperature to which a spring is subject. Almost any thermometer would suf- fice for this purpose, as only small variations are wanted, and the absolute error might be found by comparison with the traveller’s standard. But in all cases the authority for every statement not directly verified: by the traveller himself ought to be distinctly given. 154 REPORT—1840. of atmospheric temperature, solar radiation, pressure, hu- midity, fall of rain, force of wind, or electric tension. - Daily observations of the barometer are valuable, especially in tropical regions, because there the calculation of heights may at once be completely made without corresponding observations. By these means a traveller’s route across a tract of country may be traced in section, and the value of many of his local remarks greatly increased. . Observations continued even for a few days in the equa- torial parts of the globe, suffice to determine approximately the diurnal barometric fluctuation. (152, &c.) The hours seem to be everywhere nearly the same. . Optical meteorological phenomena of all kinds admit of being peculiarly well studied, from the varying points of view in which the traveller is placed. The diameters of rainbows, halos and corone, observed with due accuracy, and the abnormal phenomena which occasionally accom- pany these appearances, are facts of which as yet we pos- sess but a slender stock. We may specify the following subjects of inquiry :— (a.) The colours of the sky, their optical composition, and connection with the hygrometric state of the air. (254.) (b.) The polarization of the clear sky, (observed with Sa- vart’s polariscope) the position of the neutral points, its variations, and the cause of the inversion of the plane of polarization. (260.) (c.) The diameter of the rainbow, and contemporaneous measures of the distance of the supernumerary bows from the primary. The distance between the Primary and Secondary rainbow, measured from the brightest part of the Red. [This last is an easy and important observa- tion, especially if accompanied with a measure of the di- stance of the red of the first supernumerary bow from the primary red.] (264, 271.) (d.) The diameters (in different directions) of the Great Halos, (280); the condition with respect to polariza- tion of the parhelic circle, and other rarer appearances. (e.) The phenomena of glorified shadows, (298, &c.) in all their particulars ; and the state of polarization of the suc- cessive rings. ‘To compare the diameters of the direct corone and those by reflection formed in the same cloud. 338. The traveller on lofty mountains possesses peculiar faci- lities for the following kinds of observation :— 8. The decrement of temperature in the atmosphere. (51.) 9. The force of solar and nocturnal radiation at different SUPPLEMENTARY REPORT ON METEOROLOGY. 155 heights. The effect of atmospheric radiation in the day- time, in clear and in cloudy weather. (72.) 10. The improvement of the theory and practice of baro- metric measurements. 11. The dryness of the higher strata of the atmosphere. (190.) 12. The formation of clouds, their structure and tempera- ture (this last point is one of very considerable interest, viz. to compare the temperature of the air within a cloud with that of the comparatively dry surrounding air). 13. The formation of storms, especially thunder-storms, and the origin of hail. Perhaps no mountains in Europe are so well adapted for these observations as the middle and western Pyrenees. 339. Besides these and similar observations which experience will suggest, the traveller may often do something in the way of recommending local researches to intelligent persons situated on the spot. He may at once afford them the knowledge (which is all that many require) how to make their efforts useful,—the stimulus to exertion by undertaking to turn their labours to good account,—and the means by providing them with simple instruments, or by comparing their instruments with his own. Addition to Article 125. A paper by Dr. Richardson on the frozen soil of North Ame- rica appears in Prof. Jameson’s Journal, Jan. 1841. Addition to Article 195, on Wind. Since this was written, Mr. Osler presented at the Meeting of the British Association at Glasgow, perfectly satisfactory proof of the close connection which subsists between the diur- nal curve of Temperature and the Force of the Wind. The same analogy appears to have been made out by Mr. Rutherford, at Kingussie, in Inverness-shire (who has been engaged in hourly observations under the direction of Sir D. Brewster), although, not having an anemometer, he has been unable to give to it the precision of a law, as Mr. Osler has done. ERRATA. Page 39, 2 lines from bottom, for instruments read instructions. — 44, first line of note, for animal read annual. — 137, line 9, for gaz read gygz inch. CONTENTS OF THE SUPPLEMENTARY REPORT ON METEOROLOGY. ART. Pace 1 TET OMUCHIOTU MNS Se Oe Wai Re eee 37 Works of Reference. H5/*T TEMPERATURE (00 UP SoS UES aie ee | | AD 23 A. Thermometers 3:2. 26). el eie rer. 's ae iis eee aE 46 34 B. Atmospheric Temperature ............-.000--- 50 45 G. Isothermal dhines 53. i2i,/s0es ». fs eae «eo pie rep eal 55 51 D. Decrease of Temperature with Height .......... 57 61 Bie HAG TALON errs we. 2.0 Yai Aelia tel el oO ehh oh oka ata -- 60 81 F. Proper Temperature of the Globe and of Space .. 66 88, Solar Heat; 110, Atmospheric Heat; 114, Temperature of Space ; 117, Proper Heat of the Earth ; 129, Springs. II. ArTMosrHERIC PRESSURE. 132 AG RALOTNOUETS, cei sek es. ebtccs. Suniel txt cxoyere mene erene cee Berit of 144 B. Mean Height of the Barometer ..............4- 88 151 (C barometic Oscilationg’ '. 0.22)... as fe os Piel 90 @ 157 D. Barometric Variation with Height.............. 92 Tl. Humipiry. 164 Bi, Ey CPOMBCET He 8 igh si Ys.o: with pais eore. cota syee ieee 95 189 B. Distribution of Vapour in the Atmosphere ...... 101 TOD PTV GR War NE see eee ar Rl cae ee Se ol 102 197 EAS PATICHIOMELEDS: «cbese slecrsiete niche 2 cleuenie Sue veKepedoe ese rinkOo 201 B. Phenomena of Wind generally ................ 104 | 212 Cy Pheenomenayot Storms’ 74). «ts 6is isfcesy sya ree Oia 109 ZQ1Sie PV CLOUDS HAIN FS share a ola ene SRR he hele nee 111 933 VI. ATMOSPHERICAL ELECTRICITY .......+-. 00.0.2 0% 116 22 .5e. Valea ET HORGa cee ches oe aocid Sie etele ots eee clasts ete eran 117 DAT... Ville Ati BORA OREA LIS: 4.5.2 cs) tid.s -stemsecevaseeathe Got anita 120 IX. Orrica, METEOROLOGY. 248 A. Colour of the Sky and Clouds ................ 120 255, Dry Fogs ; 256, Blue Sun ; 257, Secondary Sunset Tints ; 258, Aerial Shadows; 259, Polar- ization of Sky-light. 262 B. The Rainbow ............ shah, 2 iw oS chose 6 ea 125 276 @eHalostand -Parheliati? Sce3 sc... ss ss eee eee tea oD 992 + CoroneyGlories, Ges ee i eee 135 DIGPONG oNUGGES TIONS <.<.0 sheets mistiael fare ars: «ists -ocickae, ah ofex totam ee 143 316 A. Public Observatories ...... tie. wrest aroha ods ik eee eeu ics 332 B. Sedentary Observations .............0.. wate 149 336 Ue bravellng Observatiotis 3352. 0. Se «. 15! Report on Professor Whewell’s Anemometer, now in Operation at Plymouth. By Mr. Snow Harris, F.R.S., &e. [ With a Plate.] Any one who has at all considered the nature and object of Whewell’s Anemometer will readily admit of how great value to Meteorology the results of its indications must prove ;—since they put us in possession of a sort of figurative delineation of the total amount of the aerial current in any direction; and fi- nally enable us to arrive at what Mr. Whewell has not unaptly termed an annual type of the winds for any given place :—by comparing the types of different places with each other, the general annual movement of the atmosphere may be in some degree ascertained. The want of an instrument which could figure at once the di- rection and proportionate velocity of a given current, so as to obtain an integral result, has been long felt in Meteorology. Common anemometers merely register the time of agiven wind from a certain point, and leave its velocity out of the question ; and although others of a more improved kind register also its pressure on a given area, yet there are none, so far as I know, which give the complete aud truly valuable result obtained from Mr. Whewell’s, viz. the total quantity or integral effect of the wind at a given place. Impressed with the great importance of such a result to Me- teorology, I have frequently, since the Anemometer was entrusted to my care, given attention to the difficulties in its practical working, and have endeavoured to render it more easily ma- nageable by ordinary observers. The objections hitherto made to the use of this machine are not altogether without founda- tion. They principally apply to the difficulty of obtaining in- struments which may be taken as sufficiently comparable ; to the want of constancy in the operation of the same instrument, owing to deterioration in the wheel-work from various causes ; to the liability of the machine to become damaged in storms ; and to the difficulty of repair. Mr. Southwood, who attended to the Register of the instru- ment for some time, and who communicated the results at the Meeting of the Association held at Liverpool, in 1837, made seve- ral valuable improvements in its construction. We have not until 158 REPORT—1840. very recently succeeded in correcting the defects attendant on the working of the machine generally. The recent improvements, in effecting which the sum of 10/. granted by the Association at its last Meeting at Birmingham has been expended, I now propose to describe; and as no par- ticular description of the Anemometer by drawings has ever yet appeared in the Reports of the Association, it may not be amiss to give an account of the whole as it now works, since I cannot but think it entitled to considerable attention, and that it must eventually come into general use in Meteorology. For the carrying on these recent improvements, the scien- tific world is indebted to Mr. Kerr of this town, on whose house the machine is now at work, and who has kindly undertaken to attend to the Register. Plate I. AAA, figs. 1 and 2.—is a circular metallic plate, move- able about an axis D, by the action of the wind on a vane V, fig. 2. A small windmill fly W, formed of brass planes and turned at an angle of 5 degrees with a plane perpendicular to the direction of the wind is fixed on this plate. The fly revolves by the action of the wind, against which it is kept by the vane V, and gives motion to an endless screw @; this screw operating on a verti- cal wheel 4 gives motion to a horizontal wheel d, through the intervention of a second endless screw, not seen in the figure, and placed on its axis. This last wheel ¢ is placed at the ex- tremity of a long vertical axis M, figs. 1 and 2, upon this is cut the thread of a fine screw carrying a nut M, figs. 3 and 10. The nut M supports a pencil p, figs. 10 and 3, which acts by means of a balance weight g against a fixed cylindrical barrel D, fig. 3. The vertical axis of the plate A moves by the action of the wind on the vane V through the centre of this barrel, as in fig. 1, and thus by the revolution of the fly, and the action of the vane in turning round the plate, the pencil is caused to de- scend and tracea line on various parts of the cylinder D, fig. 3. There are 16 vertical lines painted on the barrel, corresponding to 16 points of the compass, as in figs. 3 and 12; hence, whilst the vane V by turning the plate A causes the pencil to apply itself to that line coincident with the direction of the wind, the wind- mill W causes it to descend and trace a line proportionate to its velocity for a given time—the motion of the fly being by the toothed wheels and screws fig. 1, so reduced, that for 10,000 revolutions, the pencil only descends ;4,th of aninch. The barrel D is varnished white, and readily receives the trace of the pencil in a thick irregular line, the middle of which indicates the mean direction and velocity of the wind. When the pencil has descended to the bottom, it must be ON MR. WHEWELL’S ANEMOMETER. 159 again replaced at the top and the Register recommenced. The vane V consists of two inclined planes as seen in figure 1, and is placed so as to be nearly in the prolongation of the axis of the fly. This arrangement has been found to preserve the direction more completely and maintain the position of the fiy in direct opposition to the current. The wheel-work just described is effectually defended from wet and other atmospheric damage by means of a close cover C, fig. 4, titted securely and closely over it. In the instrument hitherto in use, the registering apparatus D, fig. 3, is placed within a smali wood cover and the whole exposed to the wind on the ridge of a house or other elevated place. We have found it, however, necessary to set the whole up in a more commodious and permanent manner. A small lantern of wood about 3 feet square and 4 feet high, within which the registering apparatus is placed, fig. 3, has been erected on the top of a house, the circular plate A A in figs. 1 and 2, being moveable over its summit and toward which it con- verges. The vane and fly are thus freely exposed to the wind whilst the registering apparatus descends within. In order to sustain the vertical axis upon which the plate A turns, a small beam BB, figs. 3 and 6, is placed across the bottom of the chamber hollowed at EK, fig. 3, in a half circle. The hollowed part E carries an iron ring R, figs. 3, 6 and 12, of about 4 inches diameter fixed to the beam B by three arms. Within this is a second ring of brass r, fig. 6, forming the nut of a third ring H, fig. 7 and 12, which can be screwed within the former and removed at pleasure by means of a small forked lever L, fig. 8. These rings preserve the position of the register barrel D, fig. 3, and admit of the easy motion of the axis of the plate A in the following way:—the lower extremity of the barrel terminates in a solid cap of brass ¢¢¢, figs. 3 and 5; this cap ¢ fits within the rings Rr, fig. 6, and there is a stud of brass s, fig. 5, projecting from it corresponding to a notch r, fig. 6, in the fixed ring; the position of the lines on the barrel indicating the direction of the wind is hence determined. The barrel D, fig. 3, is passed up through the ring R on the descend- ing vertical axis of the plate D, figs. 2 and 9, until its solid ring ft, fig.3,comes in place. It is then finally secured by screw- ing up the fixing ring H, figs. 7 and 12. When the barrel is thus secured, a screw N, figs. 3 and 5, carrying on its extremity a polished centre, is screwed up through the bottom of the brass cap of the barrel until it reaches the point of the vertical axis D, fig. 9, of the metallic plate A A, figs. 1 and 2. It is then finally secured by a small nut N, figs. 5 and 12, turned up with press- ure against the under part of the cylinder so as to prevent 160 REPORT —1840. any shake. The pencil and descending nut in fig. 3 work about this fixed barrel by means of two supports EH, figs. 2, 3 and 9 attached above to the under part of the plate A, and below to a horizontal clasp of brass P P, figs. 3 and 9. The clasp freely encircles the barrel when closed, and has small friction wheels W W W, fig. 9, inserted in it; the extremity or point of the screw M, figs. 3 and 9, moved by the wind- mill, turns upon this clasp, as at P, fig. 9: this clasp is shown in this figure open, by means of the joints at P P. This arrangement enables the observer when the pencil has descended for any given time, to remove the fixed barrel D and substitute a similar one, on which the register is continued, whilst that just removed is read off and transferred at the observer’s leisure and convenience. ‘The process of tabulation becomes in this way avery simple affair. The removal of the barrel and re- placing of the pencil at the top of the scale is easily effected. The nut N, figs. 3 and 5, is first removed and the screw within withdrawn; the brass ring H, fig. 7, is then unscrewed by inserting the points of the bent lever L, fig. 8, into the small holes of the ring seen in figs. 7, 3, and 12. Finally the barrel is withdrawn from off the axis and another substituted as al- ready described. The mechanism of the pencil is represented in fig. 10. In this figure M represents the nut traversing the screw SS. This nut is made in two parts and is held together by a steadying pin u and a clamp screw C. One of the standards of support E, figs. 3 and 10, passes between this clasp and the steadying pin, by which the pencil is faithfully steadied in the course of its de- scent along the cylinder. There isa small projecting arm on one side of the nut, to which is attached by means of a centre pin a curved piece 0; this piece is moveable about the pin car- rying within the curve a small knob of brass uv set within the curve on an axisa. The pencil p and balance weight q are attached to this knob v, and thus the pencil is gently pressed against the cylinder as shown in fig. 3. The lower part of the thread of the vertical rod s on which the nut travels is left plain and smaller than the screw above, as seen at P, fig. 9, in order to allow the nut to fall freely off ; hence if the instrument has run out at any time before attention is again given to it, da- mage to the fly and wheel work above, by the resistance which would otherwise ensue, is prevented. When the barrel has been replaced we have merely to turn back the screw C, fig. 10, and run the whole up to the head of the cylinder: again clamp the nut, and the Anemometer continues to register on the barrel as before. In order to measure and transfer the amount of wind, there is ON MR. WHEWELL’S ANEMOMETER. 161 a scale fig. 11, graduated into tenths of an inch, and termina- ting in a concave rest G, adapted to the register barrel; this scale is applied accurately along the barrel on which the pencil has registered the amount of wind, as shown in fig. 12. There are two sliding-pieces p p on this scale; these are set so as to inclose the amount of wind in any given direction and the re- sult read off on the scale. This may be also easily effected by a fine pair of compasses and a common scale. The cover C, fig. 4, is so contrived as to be easily removed at any time, being fixed on the plate A by four small studs and a clamp screw; a small trap in the roof enables the observer to inspect the wheel-work frequently, and occasionally apply a little oil to the pivots. The action of the machine is hence preserved in a sufficiently uniform state; and I have little doubt that the velocity of revolution of the fly may be fairly assumed as proportional to that of the wind. The cover C has been found to give the wheel-work the required protection, and the instru- ment now in operation here is preserved so as to be quite con- sistent with itself. It would not be at all difficult to construct anemometers, which if attended to in this way would prove very comparable with each other, especially if they were all made by the same person, or according to the same proportions in every respect; and if the respective rates of motion under the same cur- rent were compared at first with a standard instrument, a fair degree of accuracy must unavoidably be arrived at. The diffi- culties in this respect are not greater than those incidental to any other machine in which the effects of wheel-work and friction have to be considered, as for instance in the rates of different chrono- meters. If the different pivots were set in agates, and the point of the steel axis of the fly allowed to turn against an agate instead of bearing upon a shoulder, the instruments would main- tain a very uniform action. This valuable instrument being now effectively at work, I trust at the next Meeting of the Association, to have completed a graphical delineation of the integral amount of wind at this place for a whole year without any intermission. The sum voted by the Association for the purposes of Osler’s Anemometer has been applied in completing the repairs and al- terations found requisite; in the expense of tabulating the re- sults both of the instrument here and at Birmingham ; and to other expenses incidental to the observations now in progress. Mr. Osler will be prepared to lay some of the results before the Physical Section of the Association. The remaining sum entrusted to my care for carrying on the original hourly series of Meteorological Observations here, has VOL. Ix. 1840. M 162 REPORT—1840. been applied as usual in defraying the expense incurred on ac- count of the Hourly Register of the Barometer, Thermometer, &c. I have included the results of these Registers for the year 1839 in my last Report. Plymouth, September 10th, 1840. 163 Report on ‘‘ The Motions and Sounds of the Heart.” By the London Committee of the British Association, for 1839-40. Tue following Report consists of two distinct portions; the former consisting of experiments performed at King’s College, in 1839, by the London Committee for 1838-9; and the latter detailing the experiments of the Committee for 1839-40, per- formed at the Marylebone Infirmary in the present year. The former series, performed in conjunction by Prof. ‘Todd, Dr. C. J. B. Williams and the Reporter, with occasional assist- ance from Dr. Roget, were commenced but not completed, owing to the difficulty of procuring subjects and other circum- stances beyond the control of the Committee. No report of those experiments was consequently presented at the Bir- mingham meeting, or has yet been published ; and an account of them is therefore now prefixed to the report of the proceed- ings of the Committee for the current year. The experiments of 1838-9 were performed with the view to determine the physical and pathological causes of certain modifications of the motions and sounds of the heart that are presented by disease; a chief object being to ascertain how, by mechanical and other irritations and by displacement of the heart, murmurs could be produced ; how also by inflammation. Whether for example, the pericarditic friction sounds de- pend on deficient lubrication of the pericardium, or on vascu- lar turgescence, or are dependent solely on the effusion of lymph ;—how far also the natural sounds might be impaired by interrupting the action of the valves in the living subject, or by spontaneous or artificially excited abnormal action in the mus- cular parts of the cavities without structural lesion. Another inquiry was this—How far do the motions and sounds of the heart in the lower animals correspond with those of the hu- man subject; whether for example, in birds and other animals that differ more or less from man in their cardiac anatomy, there be not corresponding differences in the cardiac sounds and motions? ‘To these questions the experiments for 1838-9 supply answers in most cases, which are satisfactory in the opinion of the Committee to as great an extent as could be calculated on from so limited a number of observations: they feel however that the experiments were too few finally to decide any point of much difficulty or importance, and that M 2 164 REPORT—1840. further trials under more favourable circumstances are very desirable. The experiments referred to are the following :— Lonpon ComMITTEE.—EXPERIMENTS For 1838-39. OssERvATION I. June 14th.—Present, Doctors Roget, Todd, Williams and Clendinning. Subject, an Ass, about three months old. Pulse about 60, regular. At 8 o'clock a.m. a long fine needle with a silver ca- nula was passed into the chest, at the left margin of the ster- num between the ribs to the depth of two inches. The needle exhibited motions. corresponding to those of the heart. The needle was withdrawn, and aqua ammoniz diluted with four or five parts of water was injected through the canula. The pulsations of heart became immediately weak and very irre- gular with intermissions. 10 o’clock. Heart’s action natural. Pulse 77. 12 o'clock. Pulse 70, occasionally irregularly accelerated for a few beats. 2p.M. Still no abnormal sounds. 5 p.m. Pulse 78. June 15th, 7 a.m. Pulse about 80. At half-past 7, half an ounce more of solution of ammonia was injected as before, after which pulsations weak and irre- gular at first, but afterwards regular. Pulse 96, strong, with clear sounds. 12 o'clock. Pulse 72. Sounds natural and regular; first sound somewhat prolonged, with suspicion of murmur. June 16th. Sounds strong. Pulse 56. Canula introduced at the root of the xiphoid cartilage into the pericardium. Some blood followed the needle. Then some strong solution of salt was injected; whence irregular accelerated action of the heart. 4p.mM. Nomurmur present. Both sounds distinct. Inter- missiui every fourth or fifth beat (Ceg.). 5p.M. Pulse irregular. First sound double; generally in triplets, followed by intermission. The second sound being absent in the weak strokes preceding the intermission but di- stinct and loud at other times. Pulse 56, but variable (Wms.). June 17th, 3 p.m. Pulse 56. Still occasionally retarded. Both sounds now rough; roughness most apparent about the base of the left side, and scarcely audible in the carotids (W 8 i). June 18th, 7 a.m. Dead; but yet warm. Much blood” ON THE MOTIONS AND SOUNDS OF THE HEART. 165 escaped from subclavian vein on opening chest, and coagulated afterwards. A mass of greenish-yellow lymph in the media- stinum. The cellular membrane highly vascular and easily torn. Flakes of lymph on lower anterior left lung. External pericar- dium marked with many straight vessels, and intermediate red strie giving bright redness to the whole. Same in a slight degree on the interior of the pericardium, which contained two ounces of yellow serum. At base of heart most redness. Cel- lular substance here somewhat infiltrated with serum ; whole interior of surface of heart healthy, except some slight thick- ening and opacity of the mitral valve. A wound plugged with lymph found on the anterior face of right ventricle. OsseERvaATIon II. June 19th.—Subject, an Ass ten weeks old. Pulse 48, re- gular and pretty strong. Animal weak. By pressing between the fingers and thumb the cardiac region, the thumb being on the third rib and left side, a loud blowing was excited with the first sound, which ceased on removing the pressure. After se- veral repetitions of this experiment a short filing sound heard (by two members of the Committee) after the second sound, the first being clear. On repeating the pressure more strongly two murmurs were heard (by the same observers), one with tlie first sound and continuing after it, and one with the second sound (which was also weakened) and continuing after it. After being fifteen minutes at liberty, the animal had a deep- toned blowing with the first sound, which soon ceased, but the murmur after the second sound continued. June 20th, 8 a.m. Some murmur or filing after the second sound as before. A long needle was passed two inches and a half deep vertically to the fourth rib along the upper margin three inches from the sternum. A strong double motion was given to the needle, and a blowing, resembling a cooing, accom- panied the first sound. The heart’s action was increased though the animal seemed faint. June 2ist. Pulse 60. The needle again introduced three inches. As before, the needle presented rhythmical movements sternad and dorsad ; that dorsad being slow and forcible, and synchronous with the first sound ; that sternad being sudden, _like a fall back from gravitation, and accompanying the second sound. A murmur of a blowing or whistling kind heard with the systole and diastole also, the latter variously described by different observers. Murmurs and sounds were variously al- tered and impaired by pressing the needle flat in different di- rections ; on withdrawing the needle, murmurs were heard with 166 REPORT—1840. systole and diastole, described as rasping and filing, respect- ively (W. and T.), the natural sounds being distinct. The needle was introduced a second and third time; after the third withdrawal of the needle a loud creaking was heard with both sounds by two observers, but no constant abnormal sound by the third ; the creaking was reported (W. & T.) to continue some minutes, when the natural sounds returned, with only a slight murmur with the second sound. June 22nd. Animal dead, (7 a.m.) and cold. Considerable effusion of bloody serum in right pleura and mediastinum ; some ecchymoses and marks of perforation on left ventricle, with corresponding marks and changes on the pericardium. Perforation three quarters of an inch below, and behind or nearer to the apex than the semilunar valves. The needle had transfixed the left ventricle, slightly wounding the mitral, and penetrating the posterior wall. The anterior lamina of the mitral had ecchymoses, and the posterior lamina was perforated near the edge, with a small fibrinous excrescence on the valve. The wound passed through the opposite posterior wall of left ventricle, around which there was ecchymosis under the peri- cardium. The aortics were healthy. OsseErRvarTION III. June 23rd.—Subject, an Ass ten weeks old. Half-past 7 A.M. Pulse 60; strong and distinct. A canula was introduced about an inch from the xiphoid cartilage and for about an inch in depth, when a sound, first as of rubbing, afterwards as of blowing, accompanied the latter part of the systole; about an ounce of strong brine was then injected, when the pulsations became tumultuous and irregular, and the sounds obscure, with loud gurgling (probably from injection of air). 3 P.M. Sounds obscure, but more distinct towards the base, where a short creaking (Wms. and Tdd.) or blowing (Cg.) ac- companied the first sound, which was not audible in the arte- ries. Pulse irregular. June 24th, 3 p.m. Pulse 90, and regular. Sounds more di- stinct than yesterday; and towards the base of the heart, accompanied by leather or parchment sound. Respiration la- borious. Tender near the heart ; but eats well and is lively. June 25th, 7 a.m. A loud parchment rubbing murmur with each of the sounds, which otherwise were distinct and natural. Pulse 80. 8 a.m. Jugular vein opened. Copious hemorrhage. Heart’s action became rapid, with slight rubbing sound ; soon however ON THE MOTIONS AND SOUNDS OF THE HEART. 167 became slow and strong, with superficial loud grating or rough sound; and becoming gradually weaker, soon ceased. One ounce of serum in left pleura. Two to three ounces in pericar- dium. External pericardium exhibited several striated patches of minute vessels. The cellular tissue was infiltrated with se- rum, and the serous membrane was easily detached. No lymph on the inner surface of the pericardium, but the heart was completely coated with thin membraniform soft lymph, thick- est at the septum, and near the base. On the anterior and po- sterior surfaces numerous minute depressions or lacunz were seen in the lymph. The lymph was easily removed. On the left ventricle near the apex was an oval space of an inch by an inch and a half, of bright red patches, seeming partly vascular, partly ecchymotic, about the middle of which was a punctured wound and aclot in the muscular tissue beneath, and some ecchymoses under the corresponding endocardium. The in- terior of the heart healthy. The serum from the pericardium after standing separated into crassamentum and liquid. OssERVATION IV. June 23rd.—Subject, a stout Ass two months old. Pulse 60-70 ; strong, with sounds very loud. Quarter to 4p.m. A needle was introduced at the upper edge of the fourth rib, three inches from the sternum, and one inch deep. The heart’s action was accelerated, with obscure blowing with the systole. The needle being withdrawn, the heart’s action was slower, with double creaking or leather sound, reported by two obser- vers as accompanying both sounds, which became stronger after a few minutes. Heart’s action varying in regularity. Quarter of an hour after. Leather sound at the site of the puncture, not at all at the apex. Natural sounds there quite distinct. June 25th, 7 a.m. Both cardiac sounds loud, with sounds of friction at the basis cordis. June 26th, 7 a.m. Normal cardiac and friction sounds as before. A long needle three times introduced in different di- rections between the third and fourth ribs, and three to four inches from the sternum, without any marked effect, except sometimes on strongly depressing the handle towards the ster- num, a blowing with first sound was heard, the second sounds being normal (rubbing rather than blowing sound, Cg.). On first introducing the needle a scratching noise was some- times heard with the systole, as if from the point hitching against the heart’s surfaces. 168 REPORT—1840. A fine curved tenaculum about two inches in the curve, was passed two to three inches from the sternum, hehind the third rib, with the point toward the spine ; and when at the greatest depth, the handle was depressed toward the sternum, so as to move the hook outwards toward the ribs; a loud blowing then attended the first sound, which was distinct; the second sound was wanting, when the handle was most depressed, and obscure when the handle was somewhat raised, and restored to full force when the hook was withdrawn. Half an hour after. The first sound was accompanied with blowing between the first and third ribs, while a friction sound accompanied the second sound (the Reporter called it alto- gether friction sound, with both systole and diastole, but vary- ing in hoarseness or roughness) ; it was faintly audible in the carotids. Half-past 3 p.m. Still slight friction and blowing (roughness only of friction, Reporter) increased after the animal struggled. The tenaculum was again introduced and manipulated as before ; and again the second sound was stopped by drawing at the root of the arteries, and restored on releasing the hold; the first sound being accompanied by a loud whizzing, and the hoarse or rubbing sound being indistinct if not absent. On withdrawing the hook, a transitory crackling was heard ; on the introduction of the hook, the heart’s action became tu- multuous and irregular, and on withdrawing it, very rapid. Pulse 112. Half-an-hour after, the pulse still 112, and the first sound accompanied by murmur. ' June 27th, quarter-past 7 a.m. Sounds as before; rough mur- mur as of friction, with first sound especially. The animal then pithed, and artificial breathing established and chest opened. Heart was acting vigorously, with the sounds distinct and normal. First Experiment. On introducing a finger into the right auri-ventricular ori- fice, first sound was accompanied with a whizz, and wanted its flap at the beginning ; the whizz was accompanied by a thrill sensible to the finger introduced ; the whizz ceased and the systolic flap returned on removing the finger. This expcriment was repeated several times with the like results. Second Experiment. The hook was introduced through the auricle with a view to hook up the tendons of the mitral valves, when the flap seemed impaired not suppressed, and the whizz was uncertain. ON THE MOTIONS AND SOUNDS OF THE HEART. 169 Third Experiment. A finger placed on the auri-ventricular opening externally experienced in the systole the same vibratory or jerking motion as would in diastole be felt over the aortics ; and to the eye the same motion was visible in the former during the first sound at its commencement, as at the arterial openings during the second sound (Cg.). Fourth Experiment. A blunt bistoury was introduced into the auri-ventricular opening through the auricle, and the tendons of the septal la- mina of the mitral were cut partially, when the flap of the first sound was impaired but not destroyed. On examining the heart were found several marks of perfo-: ration of the large arteries, anteriorly to the valves, and perfo- rations just at the opening of the coronary artery, but no valve ‘was wounded. There were ecchymoses at the external mouths of the perforations, and attached to one wound was a clot witha fibrinous peduncle. On the surface of the right ventricle cor- responding to the infundibulum, the pericardium was injected and roughened by lymph, with several scratches and punc- tures ; the lymph was small in quantity and granular in appear- ance. A wound in the septum was plugged with lymph, as were all the flesh wounds in the interior of the heart. OBSERVATION V. June 29th.—Subject, a Donkey three months old. Half- past 7 a.m. Heart’s action quite normal. A tenaculum passed four inches from the sternum between the third and fourth ribs ; the handle having been lowered toward the spine, there was a whizzing heard with the first sound; but the second sound was only a little weakened. The whizz or blowing contined after the experiment with the systole, and after the flap of the valves ; but soon became intermittent, and gradually disappeared. June 30th. A fine canula was passed through the sternum an inch from the xiphoid cartilage, and about twelve ounces of warm water were injected; the cardiac sounds became pre- sently apparently distant, especially toward the sternum; on withdrawing the tube, the sounds were still distant with little impulse, but were otherwise normal, except that occasionally the systole was acompanied by blowing during embarrassed respiration. A tumour formed under the integuments of the _ sternum, through which the cardiac sounds were very faintly heard, and without impulse. 170 REPORT—1840. Heart’s action much accelerated. July 4th. Animal pithed, and artificial breathing established. The experiments on the mitral valves then repeated. The left auricle was inverted by the finger and the valves impeded or kept asunder by the finger, in the auri-ventricular opening, when various murmurs accompanied or followed the first sound ; the second sound being simply either much weakened or sup- pressed ; and the normal sounds returned on the withdrawal of the finger. ‘This experiment was often repeated with similar results. A finger being placed on the exterior circumference of the mitral and aortic valves respectively at the same moment, simi- lar jerking motions perceived in each; at the closing of the valves and evolutions of the two cardiac sounds, the finger, when in the auri-ventricular opening, was sensible of something like flapping, pushing and tension, as it were, in and by the valves, and the supposed edge of the valve was felt tense in systole; and, if divided by the point of the finger, the edges of the opposite valves were thought to give a feeling of resistance such as valvular tension must cause, supposing such tension to occur. The first sound was protracted and dull, wanting the sharply defined beginning such as a flap would give when the valvular action was interrupted by the finger. The first sound was obscure, but audible on extraction of the heart, when the organ was irritated to contraction. OssERVATION VI. July 3rd.—Subject, a Turtle, weight 150 Ibs. No distinct pulsation could be heard externally. After decapitation and removal of the callipée the heart was felt by one of the Com- mittee, pulsating regularly, and two distinct sounds were heard (Wms.), with an interval between; the heart ceased beating too soon to allow of the other member of the Com- mittee (Cg.) making any satisfactory observation. OxsservaTion VII. Comparative Observation. The observations of the Committee on the motions and sounds of the Heart had been previously made almost ex- clusively on donkeys and dogs, animals whose cardiac struc- ture and modes of action are generally known to agree with those of the human subject. It was therefore thought very desirable to extend their observations more widely over the scale, as by such means it was thought some useful generaliza- tion might be obtained, and the views of the Committee be at ON THE MOTIONS AND SOUNDS OF THE HEART. 171 the same time subjected to a new and interesting test, and, if sound, fully confirmed, but if defective, corrected; and in any event, that their future conclusions would be based on a greater variety of facts and a more comprehensive induction. The Committee therefore made arrangements for the purpose of yisiting the Zoological Gardens, and examining as many of the animals there as could easily be approached by strangers for the purposes of auscultation, &c. Before visiting the gardens, the Committee met at the Hunterian Museum, for the purpose of inspecting the preparations illustrative of the physiology of the heart that exist in that national collection, and were obligingly assisted in their search by Mr. Owen, Professor of Comparative Anatomy to the Royal College of Surgeons. With the aid of the anatomical data collected at the Royal College of Surgeons, the Committee there entered _at once on their examination of the living animals. Before ‘stating any particulars of our observations, it is proper to say that, in our examination of the wilder animals, we were much indebted to Mr. Youatt, the distinguished veterinary surgeon of the establishment, without whose kind assistance it would have been out of our power even to have attempted anything in several instances. Even with Mr. Youatt’s aid, we found it extremely difficult, in many cases, to make satisfactory ob- servations; so that, in but a portion of the subjects was it found practicable for the whole of the Committee to verify results to their satisfaction. The animals sufficiently examined by all are distinguished in the following enumeration :—They are, 1. The Ostrich. 2. The Ourang-Outang. 3. The Leopard. 4. The Seal. 5. The Balearic Crane. 6. The Common Crane. 7. The Brahmin Bull. 8. The Puma. 9. The Indian Antelope. Other animals examined to the satisfaction of some mem- bers of the Committee, were— 10. The Elephant. 11. The Dromedary. 12. The Antelope. 13. The Water Buffalo. 14. The Giraffe. 172 REPORT—1840. 15. The Lion. 16. The Nylghau. 17. The Wapiti Deer. 18. The Hyzna. In No. 1 (the Ostrich). The pulse at the heart was very vigorous, and about 60 in the minute. The systolic, or first sound, was long and obtuse ; and the second, or diastolic sound, was short, and rather obtuse. In No. 2 (the Ourang-Outang). The pulse was quick, and the cardiac sounds and rhythm like those of the heart of a child very exactly. In No. 3 (the Leopard). The pulse was 60. The first sound normal, but the second rather indistinct, as compared with the human standard. In No. 4 (the Seal). Pulse not materially different from the human. First sound long and obtuse, second sound short and clear. In No. 5 (the Balearic Crane). Pulse 130 to 140. Animal phthisical. First sound long and obtuse, second sound in- distinct. In No. 6 (the Common Crane). First sound short, and no second sound heard. In No. 7 (the Brahmin Bull). Pulse 80. Animal phthisical. First sound long and obtuse, second sound indistinct. In No. 8 (the Puma). Pulse 86. Animal sickly, probably phthisical. Grating murmur with the first sound. In No. 9 (the Indian Antelope). Long obtuse first sound, short flapping second sound. In No. 10 (the Elephant). Pulse 36. Long and obtuse first sound, and relatively short and flapping second sound. In No. 11 (the Dromedary). Pulse 48. Long and obtuse first sound, short second sound. In No. 12 (the Antelope). The first sound longer and duller, the second sound shorter and sharper. In No. 13 (the Water Buffalo). Pulse 60. Blowing murmur after the first sound, no second sound heard. In No. 14 (the Giraffe). Pulse 50. Second sound some- times double. In No. 15 (the Lion). First sound long and obtuse, second sound short and flapping. In No. 16 (the Nylghau). First sound normal, second sound indistinct. In No. 17 (the Wapiti Deer). Pulse 60. First sound long and obtuse, second sound short and flapping. ON THE MOTIONS AND SOUNDS OF THE HEART. 173 In No. 18 (the Hyzna). Long obtuse first sound, short second sound. Some other animals were attempted, but without success ; viz., the Dzagetai or Wild Ass, the Rhinoceros, the Cas- sowary, and some others. As a general observation, the Com- mittee may state, that wherever the two sounds of the heart could be distinguished, the character of those sounds and the rhythm of the heart’s motions appeared to correspond with those of the human heart, due allowance being made for dif- ferences of size in the animals, differences of temperament, and the circumstances of excitement or of disease under which many of the animals laboured, when they were subjected to auscultation, &c. EXPERIMENTS OF THE COMMITTEE FoR 1839-40. In consequence of having been nominated to conduct the experiments on the motions and sounds of the heart for the current year, without being associated with any colleagues, I thought it desirable to avail myself of the assistance of such of my friends, including the other members of last year’s Com- mittee, as could attend, and I accordingly requested the co- operation of a considerable number of gentlemen known to the public; of these, several were enabled to attend on numer- ous occasions, and one of them, Dr. Boyd, on every occasion ; so that every observation and experiment has been participated in or at least witnessed by one, or, in most instances, several of the following gentlemen: Professor C. J. B. Williams. George Gulliver, Esq., F.R.S. John George Perry, Esq. Dr. G. Hamilton Roe. Dr. George Burrows. Charles Cochrane, Esq. Dr. Rutherford. Francis Kiernan, Esq., F.R.S. J. Liddell, Esq. Francis Samwell, Esq. Dr. Edwin Harrison. R. A. Stafford, Esq. Benjamin Phillips, Esq., F.R.S.. Dr. Robert Boyd ; 174 REPORT—1840. and other gentlemen, private friends of the Reporter, and the last four-named gentlemen his colleagues in the medical staff of the St. Marylebone Infirmary. The experiments were performed in a convenient locality immediately adjoining to the Marylebone Infirmary, and prin- cipally on donkey colts of a few months old. In the latter part of the series other animals, and especially dogs, were used, partly for economy, and in order that the limited pecu- niary resources of the Committee might not be prematurely exhausted, and partly because certain experiments contem- plated were expected to prove more easily and decisively practicable on the larger heart of the ass than on any smaller, such as that of the dog; and that, in any event, it was de- sirable to extend the range of observation, as far as practi- cable, over the animal scale. The mode of preparation was in all cases nearly the same. In almost every case sensibility was withdrawn as completely as was practicable by one method or the other. In donkeys we availed ourselves of the stupefying property of the woorara poison, for a packet of which the Reporter had been indebted, since 1838, to the kindness of Sir B.C. Brodie, Bart. The woo- rara was brought into operation by injecting a couple of grains of it, partly dissolved, partly suspended in water, into the exter- nal jugular vein, as practised by Mr. Mayo in an experiment of Dr. Hope’s, and the injection was usually followed in a very few minutes by complete insensibility. In the smaller animals prussic acid was used in several instances; and ina few cases the subject was stunned by a blow on the head. Artificial breathing was used in every warm-blooded subject, by means of a bellows and long flexible tube kept loose in the trachea. The chest was opened nearly as directed by Galen*, and as practised by former Committees ; five or six ribs were sepa- rated from the sternum and broken near the articulations, and bent back over the vertebra. In every case, whether during the preparation or subsequent observation, all convenient means were used, as advised by Galen}, to prevent or lessen hemorrhage, in order to avoid as much as possible the anomalous modes of action attending extreme vascular deple- tion, and to prolong the opportunities of observation and experiment. The observations about to be detailed consist partly of experiments in continuation of the inquiries of former Com- mittees, and partly of experiments made with a view to decide * De Admin. Anat. |. vii. c. 12. + Loc. cit. ON THE MOTIONS AND SOUNDS OF THE HEART. 175 several points in dispute amongst physiologists of authority, which were not investigated by those Committees, and which seemed to the Reporter yet unsettled, and at the same time important enough to call for direct experimental investiga- tion. The following are the principal of those undecided questions :— 1. With respect to the rhythm of the motions of the auri- cles and ventricles, several living distinguished physiological writers appear to hold, that those cavities act in strict alterna- tion with each other, and not continuously or in immediate succession, the auricles being first always in systole and dia- stole, and the ventricular actions being last before the Rest, as described by Steno, Harvey, Lancisi, Haller, Senac, &c., and by Hope, Williams, Carlisle, Pennock, and Moore, and other living authorities. 2. With respect to the share in the circulation due to the auricular systole, it has been held to be active and of much importance, by Hervey, Senac, and others; while several living writers of great weight, adhering apparently to the views of Galen, Vesalius, &c., seem disposed to refuse to the auricles any very influential or positively important share in the cardiac operations; for examples I may cite Dr. Elliotson, Prof. Bouillaud, Dr. Hope, Sir B. C. Brodie, &c. 3. With respect to the shape and dimensions of the ven- tricles in systole, it was held by Galen, Vesalius, Harvey, &c., that the heart is shortened in diastole and lengthened in systole; but the observations of Steno, Lower, Lancisi, Haller, and others, gave currency to opposite views; of late, however, the ancient opinion has been revived, for example, by Prof. Burdach and Prof. Bouillaud, as I understand their observa- tions, and by Drs. Pennock and Moore, the latest experi- mentalists on the subject that I know of, except my friends and myself. 4. With respect to the precordial impulse, the great ma- jority of physiologists, adhering unqualifiedly to the ancient Opinion advocated by Hippocrates and Galen amongst the Greeks, and by Vesalius, Harvey, Lancisi, Senac, Haller, Hunter, and almost all modern writers, ascribe the cardiac pulsation to a blow or stroke (in the popular meaning of those words) given by the heart’s apex in systole to the ribs; while, in opposition to this view, may be cited the experiments of several recent observers, and the arguments of Mr. Carlisle, of hg er in his last edition, of Mr. Bryan*, Dr. Billing, c. &e. 5. With respect to the diastole of the heart, it was held by * Lancet, v. 29. 176 REPORT—1840. Galen and Vesalius to include a strong force of suction, by which the venous current was much forwarded, and the auri- cles were more or less emptied; and this power of inhalation or suction has been adopted by numerous living authorities, ex. gr. Prof. Bouillaud, Dr. Hope and Dr. Copland, and has even been extended to the auricular diastole, ex. gr. by Dr. Alison and Dr. Elliotson. The exertion, however, of any such force has been distinctly refused to the diastolic state by Harvey, Lower, Senac, &c., and appears, Dr. Joy remarks, to rest on no satisfactory experimental evidence whatsoever. 6. In addition to active pulsations observed in certain ani- mals in the veins (as in horses, rabbits, dogs, fowls, frogs, &c.), there have been noted by several experimentalists, of whom it is sufficient to name the great Haller, certain passive pulsa- tions, viz. an abrupt diastole of the vein attending the first part of the heart’s systole or the auricular contraction, and an abrupt systole of the vein attending the first part of the heart’s diastole on the dilatation of the auricle; but the connexion between the venous regurgitation and the auricular systole has been doubted by several apparently, and even denied by Dr. Elliotson. . 7. Reverting to the auricular functions, the systole of the auricles has usually been regarded as unattended by any in- trinsic sound. Dr. Hope denies that any such sound occurs, and on mechanical grounds seems to affirm that it is not pos- sible; and Dr. Joy calls the auricular systole a “ silent” act*. Six months, probably, or more, however, before the Committee for 1840 had even begun their experiments, Drs. Pennock and Moore had, unknown to the Reporter and his friends, detected, as they conceived, an auricular systolic sound, in a series of very interesting experiments, of which an account is pub- lished in the American Journal of Medical Science, Part L., for February, 1840. Some other often-agitated and still unsettled points have appeared to the Reporter, in like manner, to stand in need of further examination; ea. gr. 1. the sizes of the ventricles, &c. with respect to each other; 2. the production of sound by certain muscles, while vigorously contracting ; 3. the rhythm of the cardiac and arterial pulses, &c. &c. Finding on all the preceding points considerable differences of opinion, and per- ceiving that, in many instances, the decision of highly-distin- guished and leading physiological writers was at variance with the best hitherto-recorded experiments and observations, the Reporter found forced on his mind the conviction, that on | all or most of those points further data were wanting, and * Library of Practical Medicine. ON THE MOTIONS AND SOUNDS OF THE HEART. 177 experiments less ambiguous and more pointed and conclusive. Under such impressions, the Reporter felt himself at liberty, if not positively called on, to advert to various questions above alluded to, which had not been handled by former Committees, provided that, by any unlooked-for good fortune, if not through some new and happier experimental combinations, he should succeed in eliciting pertinent and decisive facts. Acting on such views, the Committee has put to the test of experiment, to a greater or less extent, several of those questions, with results now to be stated. It may be proper to state, that the instrument used in auscultation was exclusively the flexible ear tube; the wooden stethoscope, comparatively inconvenient in almost all cases, being found quite unsuited for such experiments. OsserRvATION I. June 11th.—Subject, a Donkey about ten weeks old and sound in all respects. Phenomena: Various spontaneous tr- regularities in the cardiac action and sounds ;—jerking upwards Sc. of periphery of internal valves in systole ;—appearances of auricles in action ;—effect of valvular obstruction on first sound. Heart, when exposed, acting strongly and quickly. Second sound indistinct, and loud murmur with the first sound. S. 1. On placing the finger on the outer periphery of the mitral valves, an upward jerk and thrilling motion sensible, similar to that observed over the arterial valves. 8.2. At the moment of auricular systole, were noted a dimpling of the appendix, and an abrupt contraction in all its dimensions, and a sinking (as it were) downwards and in- wards, followed by a gradual return to the state of promi- nence and distention that characterize the auricular diastole. Several times was observed a slight and partial active contrac- tion of the auricle, followed by relaxation in the intervals of full and complete auricular systole and diastole, as if from transient spasmodic disturbance. S. 3. The second cardiac sound observed at intervals to be for many minutes together wholly wanting, without obvious cause; no operation upon the mitral or other valves having been hitherto attempted. 8.4. The left auricle was inverted successively by the finger and by a probe, so as to impede the action of the mitral valves; the finger was sensible, when placed in the mitral orifice, of an abrupt though gentle concussion in the systole of the ventricle, and (it seemed to me) as if it were VOL. Ix. 1840. N 178 REPORT—1840. pushed by a cord or membrane stretched obliquely across the passage, and brought suddenly to a state of tension; and at the same time the sensation of jerking upwards was much less distinct when a finger was placed over the valve externally. The probe also, when held loosely in the orifice (enveloped, like the finger, in the inverted appendix of the auricle), was felt and seen to be pushed back in each systole between the fingers. S. 5. At the moment of introducing the inverted appendix into the internal opening, the sharp well-defined beginning of the first or systolic sound was wanting or obscure; and that sound seemed to several observers less abrupt and more gradual in its development. OsseErvATION II. June 13th.—Subject, a stout Ass two to three months old. Phanomena: Abnormal murmurs, without structural defect ;—motions of the ventricle in systole, as apparent to the eye and hand ;—same of the auricles ;—rhythm of the motions of auricles and ventricles ;—auricular hemorrhage not sus- pended in diastole, and augmented in systole of auricle. S. 1. Heart acting normally and vigorously before the in- jection of woorara. Immediately after the operation was com- pleted, a murmur was observed with the second or diastolic sound, with a slow cardiac action; the first or systolic sound being normal. S. 2. In systole, motion first distinctly observed at the fundus, especially on the right ventricle, where any phzeno- mena about the arterial orifice are most easily observed in animals lying on the right side; apex almost simultaneously moved with fundus. ‘These systolic motions in the ventricles were preceded by a dimpling and shrinking inwards and downwards of the auricular appendices, but by a very minute interval, so that the auricular motion seemed as it were but the first portion of a more extensive movement affecting the whole heart. S. 3. Before opening the pericardium, needles were passed horizontally through that organ without wounding the heart, and so that they lay exposed to the eye in their whole length, except the minute portion actually penetrating the pericar- dium, and over the following points,—viz. over the auricle, over the periphery of the mitral orifice, and over the apex; and observation was made through a roll of paper employed to limit the field of vision, and a succession of motions was di- stinctly noted; first, about the fundus and insertions of the ON THE MOTIONS AND SOUNDS OF THE HEART. 179 great arteries, and most strikingly over the appendices auri- cularum, and thence propagated as it were toward the free extremity of the heart, being perceived in the body of the ventricles next after the fundus, and at the apex last, as if an impulse in a compressed fluid, or a wave commencing about the insertions of the arteries, had been propagated along the heart from fundus to apex. S. 4. After opening the pericardium, small triangular bits of white card were applied so as to adhere to the left appen- dix, fundus of left ventricle, middle of same cavity, and close to the apex; and observation was made, as in last experiment, through rolled paper, and with like results (as in S. 3.). S.5. And this seeming propagation of motion was per- ceived next in another way, viz. by pressing gently on the fundus and body of the ventricle and on the apex, by which was elicited a sensation, or series of sensations, as of a pro- gressive movement of an undulatory character directed from fundus to apex, and resembling, to a considerable extent, that given by a dropsical abdomen, or hydrocele, &c., when ap- propriately percussed. ; 8.6. During a very vigorous action of the auricles, and at a somewhat advanced period of the observation, the shrinking and dimpling, in its centre, of the appendix in its systole, was likened by several observers to an effect either of suction or of some traction exerted on the appendix from some point about the auri-ventricular opening, more especially because it seemed often separated in time from the ventricular tension, roundness and impulse (2. e. systole) bya scarcely perceptible interval. S. 7. Toward the end of the observation, and during a tolerably regular and vigorous action of the heart, the tip of the left auricle was snipped off; after which the contractions of the appendix became indistinct, those of the ventricle being at first little affected. On the instant of cutting off the appen- dix, a profuse flow of blood occurred in a stream slightly in- creased by a jet during systole of the auricle, and continuous, and without any jet, during diastole. Note.—The heart ceased to beat after about three quarters of an hour of observation, owing to the inflating tube becom- ing obstructed by a clot of blood which escaped timely detec- tion; it was quite healthy ; the ventricles appeared not to differ in size. N 2 180 REPORT—1840. OssErvATION IIi. June 22.—Subject, a Donkey about six months old, in good health. Phenomena: Results of application of pressure in various ways to the ventricles ;—rhythm and manner of motions of fundus and apex in systole and diastole ;—motions in the arteries and over the valvular orifices ;—action of the sinuses in systole of auricles ;—shortening of heart in systole ;—effects of wounding an auricle, §c. §c. S. 1. Callipers were applied to the ventricles, as if to take the diameter of the heart. The legs of the callipers before use had been fastened together by an elastic chord of con- siderable resisting power. In whichever direction the instru- ment so prepared was made to embrace the ventricles, whether exactly transversely or obliquely, the uniform result was, that the legs of the instrument were separated with force, and re- ceded from each other in each systole, and approached each other in each diastole with depression of the part of the parietes they pressed on; which depression wholly disappeared in the systole, giving place to an opposite state of the parts, or toa state of convexity and apparent protrusion. S. 2. The finger and thumb were then applied to opposite sides of the ventricles, and were felt to be abruptly pushed outwards in systole, and to approach each other in diastole, if acted on even slightly by the flexor muscles, and with marked depression of the parietes in diastole, during which no sense of active resistance was experienced. S. 3. A wooden stethoscope was then placed on the ven- tricles, and kept erect by means of a roll of paper large enough to give the instrument full freedom of motion; and the uniform result was, that wheresoever placed on the ventri- cles, the stethoscope was heaved up with a jerk at each systole (to the height of half an inch near the fundus), and subsided at once in diastole, causing in the parietes a deep depression, which was wholly removed by the systole, and succeeded by an opposite shape of the surface. S. 4. To the eye and hand the fundus appeared to become round, hard, and elevated, and to give impulse somewhat sooner than the apex, as if the systole was developed earlier about the fundus than at the free extremity of the heart. S. 5. To the fingers, during the systole of the ventricles, a feeling was communicated, as of an undulation in a com- pressed fluid, very distinct, and directed from fundus to apex, and resembling sensations familiar to physicians in ascites, hy- drocele, &c., when properly percussed and manipulated. ON THE MOTIONS AND SOUNDS OF THE HEART. 181 8. 6. On touching the arteries close to the heart a feeling, as of efflux and reflux, was very distinct, especially in the aorta, the former coinciding with the systole of the ventricles, the latter with the diastole. At the same moment with the out- ward current in the arteries, or during the ventricular systole, a peculiar jerking upwards of the periphery of the auri-ven- tricular orifices,—and a similar eccentric movement was ob- served over the arterial openings during the reflux current or undulation in the vessels, ¢.e. during ventricular diastole. S.7. The sinuses of the auricles were found by the touch to contract vigorously, before the ventricles considerably, and even before the shrinking, &c., or systole of the appendices. S. 8. Small three-triangular pieces of white card were made to adhere to the fundus and apex cordis respectively, and ob- servation was made through a roll of paper sufficiently large to take in, at a convenient distance, both extremities of the organ, and held so that each white object rested on a distinct limb of the tube’s mouth, and every change of distance be- tween the points dotted white was readily detectible,—and the uniform result was, that the apex approached the base in systole and receded again in diastole, and the range of oscil- lation seemed about rd of an inch. S. 9. While the heart still acted, but with much diminished force, a cut was made in the right auricle and a copious flow of blood obtained, having slight jets in the auricular systole, and immediately before the ventricular hardening, elevation, &c., but being continuous during diastole. Note.—The ventricles appeared not to differ in size on care- ful examination—post mortem cordis. OsservaTion IY. dune 27.—Subject, a stout Ass three to four weeks old. Heart acted very vigorously until weakened by hemorrhage, and continued to beat with considerable energy for two hours, when it was extracted, still contracting. Phenomena: Effects of various forms of pressure on the heart ;—rhythm of cardiac and arterial pulses ;—ventricular systole ;—auricular ditto ;— sound of auricular systole ;—pulsation of cava ;—auricular diastole ;—spontaneous or incidental variations in cardiac sounds ;—protrusion of septum into right ventricle in systole. S$. 1. A stethoscope loaded with 2 Ibs. weight of shot in a bag, was placed on the heart before opening the pericardium {as in experiment 3 of last observation), and was raised at each systole with a sudden heave or jerk, and with much 182 REPORT—1840. foree, and subsided immediately on the supervention of dia- - stole, causing a deep depression in the previously convex sur- face of the ventricle. This experiment was repeated toward the close of the observation, and after the heart had been ex- posed for 1 hours and with like results in all respects. S. 2. The pulse of the femoral artery, being compared with that of the heart, was found to follow the latter by a distinctly perceptible interval, but one very minute. S. 3. To the eye the apex and fundus cordis approximated to each other in systole, and receded in diastole. ‘lhe motions of those parts coincided to a great extent, but not entirely, but rather as parts of a series of concatenated movements, of which the former part was the profound undulation, harden- ing and rounding of the fundus, and the latter part the hardening, shortening, and slight elevation of the apex; be- tween these successive appearances, no very distinct interval ; they passed into each other by an undulatory sort of motion, commencing at the fundus, and passing with extreme rapidity along the ventricles to the apex. S. 4. Threads were passed through the appendices of the auricles, and being held tense, so as to impede the auricular systole, were felt to be drawn downwards with much energy immediately before the systole of the ventricles, the auricular contraction being completed, while the ventricles were still developing their systole. S. 5. Toward the close of the first hour of observation, and while the heart in its different parts acted with much energy, the auricles were observed for a time to contract with a rhythm above double that of the ventricles (owing probably to the irritation excited by passing the needle and thread through the appendices, and pulling at them afterwards), and a sound was detected resembling very much, except in volume, the first or ventricular systolic sound, and accompanying the auricular systole. The sound was short, rapid, obtuse, without any jerking motion, and coincident exactly with the auricular systole, and in number double (or rather more) the sound of the ventricular systole. This sound was found to attend the systole of the right auricle as well as that of the left, at a time when the action of the latter was too feeble to give sound. S. 6. The large pectoral veins, especially the cava, were observed to pulsate with the auricular systole, something as the arteries do with the ventricular, but comparatively very feebly ; first came the diastole of the vein and then the systole, and then the Rest, and the former followed immediately on ON THE MOTIONS AND SOUNDS OF THE HEART. 183 the auricular systole, and the latter on the diastole of the auricles, both in the inferior and superior cava; no other motion was noted in the veins. 8.7. The diastole of the auricles was a gradual swelling and enlargement of the visible parts of the cavities in all directions, requiring for its completion as much time as several systoles would do; and followed, on the instant of the full distension of the appendices, by systole of the whole heart,— first in the auricle, and then instantly in the ventricles: during its diastole, the auricle seemed to the eye to emerge, as it were, from the sinus venosus, and to swell out from a state of collapse, such as suction inwards toward the ventricle might cause, if any such force as suction existed in the heart. S. 8. In this, as in every observation, abnormal murmurs were observed at various moments, viz. immediately on the in- jection of the woorara, and at other times, but especially when pressure was made, whether intentionally or otherwise, over the orifices, exterior and interior, of the heart. ‘Toward the close of the observation, a loud musical sound was detected in the pulmonary artery with the diastole. At various times, for short spaces, the second sound of the heart was indistinct or absent, or masked by murmurs, without obvious cause in most instances, other than abnormal modes of action from irri- tation, hemorrhage, &c., exclusively of known structural changes. The first sound of the heart was often modified in various ways, and attended by murmurs, but never was want- ing so long as the heart acted with any energy. Toward the close, however, when the ventricular systole had become slow and gradual from quick and abrupt, the first sound was either very feeble, or not distinguishable at all. S. 9. The pulmonary artery was cut open; after which the first sound was still heard, but rather obtuse. A finger was then passed into the right ventricle, and the septum was felt to project convexly into the cavity, and in each systolic effort to press against the finger. Note.—Post mortem. One valve of the pulmonary orifice was found slightly injured by a puncture made in the course of experiments, in which the parietes cordis had been irritated to abnormal action by means of a needle. Wherever the needle penetrated into a cavity of the heart, there a clot was found, or at least a coloured plug of lymph in the internal opening. Post mortem. The ventricles were found to be of the same dimensions on careful examination. 184 REPORT—1840. OssERVATIONS V. AND VI. July 1st, 1840.—In two observations, one on a Frog and a second on a Rabbit, the following results were obtained :— Rhythm: The first contraction after the pause or cardiac diastole was observed in the vena cava, to which immediately succeeded contraction of the sinus, and afterwards, immedi- ately, of the appendix of the auricles ; to which latter, imme- diately succeeded the ventricular systole; and the diastole, or relaxation of each part, succeeded in like order,—that of the vein first; then of the auricle, of which the appendix seemed later in its diastole than the sinus or body; then of the ven- tricles. Those motions were much slower than in the human subject—somewhere about fifty beats per minute. The series of systoles above mentioned succeeded each other, so that at a little distance they appeared collectively like an undulation commencing at the cava, rather than a series of independent actions.—Systole of ventricle: In diastole the ventricle was round, full, protuberant, and dark in colour; but on the supervention of systole changed rapidly in shape and colour, from purple, becoming pale flesh colour, like veal; and from round and broad, becoming apparently narrower and more conical and depressed ; being obviously lessened in all dimen- sions, but most strikingly in the transverse. The action of the heart lasted for.an hour or more with great regularity ; the auricles acted for some time longer than the ventricle, especially the right auricle. OsservatTion VI. In the rabbit, the heart did not beat at any time very vigorously or regularly, and ceased altogether after 20 to 25 minutes, although respiration was maintained by the bellows with ease. The Rhythm: §.1. The first motion after the Pause or ventricular diastole was observed in the base of the auricles, and on the right side in the expansion of the jugular and sub- clavian veins, which in the rabbit, as Steno has noted, seemed to replace the superior cava. This vessel, whose dimensions were very large compared with the heart, and which wound round the root of the heart in its way to the auricle from above downwards, and from left to right, continued to pulsate for some time after the ventricles had ceased, and even after the adjoining auricle had been for some minutes inert. Nearly, but not quite, at the same instant of time with the vein, the base and then the apex of the auricle were seen to contract; after which (but not so quickly as might have been expected from ON THE MOTIONS AND SOUNDS OF THE HEART. 185 other observations, owing probably to delay in the establish- ment of artificial breathing) the ventricles entered into their systole, and the diastole followed in like order ; first, the venous expansion, next the base and appendix of the auricles, and last of all the ventricle. S.2. In the systole some change of colour was observed in the ventricles, from darker to paler, and the same in the auricles. S. 3. Toward the close of the observations, the auricles acted much more frequently than the ventricles, and especially the right auricle. In the ventricular systole the apex was thought to move slightly outwards and to the left, or away from the septum or central axis of the heart. Oxsservation VII. July 2nd.—Subject, a snake of good size, poisoned with prussic acid, so as to be insensible. Heart beating very slowly and rather irregularly at first, from 15 to 20 beats per minute only. Rhythm of motions: After a long pause, first motion ob- served in sinus of auricle, and then in appendix, being the auricular systole; immediately after which the ventricular systole, but with no complete interval between the end of one and beginning of the other systole. After the systoles re- spectively came the diastoles in like order, and then a long pause, equal sometimes to 3 or 4 or more beats. At each auricular systole, a swelling observed in the cava and pulmonary veins, extending some way down from the heart. This appearance resembled a wave of reflux excited by the action of the auricle. It was not observed in any part beyond a point of the vessels on which pressure was made. In the systole, the ventricle shrank concentrically, being shorter and narrower, but also rounder and more oval, than in diastole ; the ventricle (which might be called bicornute, being obtusely pointed at either extremity,) had either horn or ex- tremity raised slightly in systole, and depressed again, as if by gravitation, in diastole. The cavities systolized and diastolized still after the observation was completed, or for more than an hour, and more regularly than at first. July 2nd.—The ventricle ceased beating after about twenty hours, but the auricles were still pulsating regularly after more than twenty-four hours. The rhythm of the motions of the heart as before, but the reflux wave or diastole of the veins now less distinct, owing probably to the emptiness of the heart. And in lieu of the regurgitation wave marked by a 186 REPORT— 1840. diastole, followed by a systole, and then a pause in the veins, there was observed an opposite order of the motions, viz. 1. venous systole; 2. venous diastole; 3. then the pause. Several times the motions of the veins were observed alone, and not preceded by auricular contraction, or accompanied by it, as, toward the close in other observations, auricular con- traction had often failed to excite or be followed by ventricu- lar systole. OssErRvaTION VIII. July 4th.—Subject, a Donkey nine months old, in good health. Pulse beating well in precordia about 70 or 80. Opera- tion of injection tedious, with considerable hemorrhage ; whole operation lasted kalf an hour, and heart acted for considera- bly more than an hour. When opened, the heart was beating quickly (above 100) but regularly. Second sound indistinct. Phenomena: Effects of pressure on the heart ;—action of threaded auricles ;—no sound, and why ;—manner of auricular diastole ;—resistance to pencil in mitral orifices, and how caused ;—pulsation of cava;—phenomena of ventricular sy- stole ;—mechanism of cardiac impulse ;—valvular jerk over the mitral opening in systole, and modifications of first sound arti- ficially produced ;—hemorrhage from left auricle ;—relative sizes of ventricles. S. 1. The stethoscope, loaded with 4 to 5 lbs. of shot, &c., and placed on the ventricles as before, was jerked up by each systole, and subsided and deeply indented the parietes in each diastole. S. 2. The callipers were applied as before, but with a ten- sion much exceeding that formerly used, and with a similar but not equal result ; the heart being considerably less vigor- ous, as well as the spring much stiffer. The action became much hurried under the pressure of the instrument, but its legs were pushed asunder with force in systole, and a deep indentation was caused by them in the parietes in diastole, which did not wholly disappear sometimes in systole. S.3. The tip of the appendix of the left auricle was threaded as before, and the auricle and ventricle acted nearly but not exactly in alternation, and the thread was felt to be forcibly drawn downwards at the moment of auricular dimp- ling and systole. S. 4. No auricular sound could be distinguished, apparently less attributable towant of energy in the auricle than to the rapid beat of the heart and sudden supervention of the ventricular sy- stole before the completion of the auricular. The left appendix ON THE MOTIONS AND SOUNDS OF THE HEART. 187 was repeatedly inverted with a pencil and with the finger, and on the instant of being let free, by withdrawal of the pencil, &c., recovered its shape and position, appearing to emerge with rapidity out of the auri-ventricular orifice and sinus, appa- rently owing to a continuous and copious influx of venous blood into the appendix, especially during the systole of the ventricles. S. 5. In experiments on the mitral valves, repetitions of former trials, and with inverted auricles, some resistance, as of a hard edge, was repeatedly felt by the finger, and the pencil was pushed outwards with some force, but the edge felt was suspected to be the edge of the interior orifice and not that of a valve. On the inner side, or that next the septum, the resistance in systole was more energetic than on the outer. S.6. The thread that had been passed through the ap- pendix was drawn upwards, to check the systole of the auricle during auscultation, but the operation was with difficulty per- formed, and at all events no perceptible difference resulted ; the first cardiac sound appeared unchanged. S. 7. A slight motion of the cava was observed accompany- ing the auricular systole, viz. a diastole followed by a systole ; both slight. S. 8. In systole the ventricle became rounder, harder, tenser, and shorter; both fundus and apex, but especially the latter, were seen to be elevated, and the apex seemed to turn slightly from left to right. S.9. An eccentric impulse, or abrupt push outwards, was perceived on whatever part of the ventricle we touched, while the heart acted with any energy; and this push or impulse was most striking, though least powerful, just at the apex, on account, as it seemed, of its pointed form. S. 10. An undulatory sort of motion was perceived in systole from fundus to apex, along the parietes. In addition to the general eccentric impulse, there was observed over the orifices, arterial and auricular, a jerking motion not observed elsewhere; and this jerking was indistinct or null over the in- terior orifice, in a subsequent experiment, in which the mitral valves were prevented from closing by a slender instrument something like scissors, the parts of which beyond the joint were introduced, through the auricle, without inverting it, into the auri-ventricular opening; and while the blades were kept separate, the first sound, as heard on the ventricles, was found to begin dull and obtuse; and an obtuse beginning, and a well-defined beginning were heard alternately, according as 188 REPORT—1840. the blades were separated or brought together, and as conse- quently the valves were obstructed or left free. . S. 11. The tip of the left auricle was snipped off and he- morrhage was excited, which was constant but with slight jets at the systoles of the auricles. OssERVATIONS IX. and X. July 7th.—Operated on two Rabbits ; one a large vigorous domestic one, and the other a smaller wild one; both stunned by a blow on the head. The larger one was violently convulsed before death, and when the chest was opened the heart was not beating, and the only result obtained was— S. 1. Distinct beatings in the large vein on the left side which winds round the base of the heart to empty itself in the right auricle ; the actions observed were a systole followed by a diastole, and then a short pause ; there was no auricular sy- stole; the venous beating continued for many minutes. , S. 2. The second heart acted for some minutes with some energy, especially the right cavities; the left cavities were drained by hemorrhage, owing to an accidental wound in the superior great vein in opening the thorax. For some minutes the rhythm of the action of the cavities went on normally ; first, the very rapid and abrupt auricular systole, and then immediately the ventricular systole more gradual and of longer duration, and then the pause. S. 3. When the left ventricle acted, the apex cordis seemed slightly deflected to the left in systole, dragging the apex of the right after it; and when the right ventricle acted alone, no de- flection was observed. 8. 4. For a considerable time after the cessation of the left side, the right cavities acted regularly, but after five to ten mi- nutes, the ventricle especially began to flag, and the auricle then acted frequently without any following ventricular systole. But on one occasion, without obvious cause, the auricle became sluggish, and even for a few moments motionless, while the ventricle acted by itself more than once. S. 5. In the systole, the apex approached the base, and the opposite sides approached the septum cordis, and the whole organ became rounder and more globular. In one direction, viz. the vertical, the heart always, when acting with any energy, became larger, while every other diameter was diminished. S. 6. After cutting out the heart, and before cutting out, but after cessation of spontaneous motion, systole was easily excited by irritating with scissors, etc., and after the left had nearly wholly ceased to answer stimuli, still the right ventricle ON THE MOTIONS AND SOUNDS OF THE HEART. 189 contracted on the point of a scalpel being applied to the left ventricle. OsBsERVATIONS XI. and XII. July 11.—Phenomena: Stroke and sound obtained as if from locomotive force in systole of ventricles ;—rhythm of the heart's motions ;—manner of auricular action ;—same of the ventri- cular-venous motions ;—mechanism of the cardiac throb or im- pulse ;—mode of hemorrhage from a wounded auricle. Subjects, two Donkeys operated on; one about six weeks old, the other about two and a half months; both rather weak from fasting twenty-four hours, owing to being too young to eat or drink properly. Each heart ceased to beat after about half an hour. First animal had his forehead beaten in so as to stun him, and chest then opened. Heart acted quickly and not very regularly. No distinct second sound ; no auricular sound. S.1. Before opening pericardium, a hard flat body, having a piece of lead weighing about a quarter of a pound fixed on it, was placed on the heart, and a stethoscope was held at a short distance over it, z.e. ata quarter to half an inch, and at each systole of the heart the lead rose up abruptly and struck the stethoscope with a tick, audible at some yards distance, and receded with diastole to sometimes nearly half an inch, and again rose up and impinged on the tube in systole, and so on. S. 2. The pericardium was then opened, and the auricles and ventricles observed. No auricular sound could be detected. The auricles acted immediately before the ventricles, and after the pause or rest, and very abruptly and rapidly: the heart acted rapidly, probably considerably above one hundred per minute. S. 3. The auricles were observed in systole to dimple and contract all round from periphery to centre, as in former ob- servations. S.4. The changes of shape in the ventricles were particu- larly plain and striking—the apex moved slightly upwards and to the left, and was drawn toward the base in systole, while the horizontal transverse diameter of the heart, as the animal lay on its right side, was diminished, and the transverse verti- cal diameter, and that alone, was increased, owing to the heart becoming from flattish, inferiorly and superiorly, convex, and from in the centre compressed or depressed, strictly globular or protruding, so that the central longitudinal axis was elevated during systole, and lowered in diastole, while in diastole the apex rather approached the sternum from which it had receded in systole, owing to shortening of the organ. S. 5. The veins were observed, and except perhaps a slight 190 REPORT—1840. undulation downwards during auricular systole evinced by a diastole followed by a systole, both very slight, nothing decided was observed. As in all former observations the ventricles and auricles respectively acted together. OBSERVATION XII. The second and older animal was prepared by injection of woorara, and, after establishment of artificial breathing, the left ribs were cut quite close to the mesial plane, so as to expose fully the apex in every motion. (Note.—The former was opened in the same way and with the same effect.) The pericardium was then opened, and the following results were obtained. S. 1. The hard substance (sole leather) weighted with lead, was applied to the heart, and the same result as in the former experiment obtained, viz., a sudden abrupt elevation or jerk upwards of the lead was obtained, and a stroke against the stethoscope heard distinctly at several yards, and the range of oscillation or motion of the lead was about half an inch. S. 2. On opening the pericardium the auricles and ven- tricles were acting as in the former observation, viz., the auricles first after the rest or pause, and the ventricles imme- diately after the auricles. No auricular sound was detectible ; no distinct second sound heard. Heart acting hurriedly and with varying quickness, but always above the healthy standard. S. 3. The motions of the ventricle very conspicuous, and as in last observation, viz., striking diminution of horizontal transverse and of longitudinal diameters, and increase of trans- verse vertical diameter in systole, and in diastole increase of the two former diameters, and decrease of the last. And in sy- stole the apex was raised, as was the whole body of heart, by an elevation of the central longitudinal axis, which was effected partly by the assumption of a globular form in the previously compressed central inferior surface, and partly by the visible protrusion of the previously depressed central superior surface of the ventricles. So long as this observation lasted both auricles seemed to act with equal pertinacity ; the right auricle being however snipped, and long after the ventricles had ceased, the blood gushed out of the right auricle only when the auricle con- tracted, and the hemorrhage ceased nearly during the diastole of the auricles. S. 5. No other appearances observed in the veins than in the former experiment, viz., a slight diastole with the auricu- lar systole followed by a systole with auricular diastole. ON THE MOTIONS AND SOUNDS OF THE HEART. 191 S. 6. In neither of the two preceding observations did the auricles and ventricles exactly alternate, but in each, whenever observation was carefully made, the auricular systole imme- diately preceded the ventricular; and the ventricular diastole preceded the pause or rest, which last was first interrupted by the abrupt auricular contraction. OsservaTions XIII. and XIV. July 15th.—Subjects, a Donkey {about a twelvemonth old, prepared with woorara ; very little blood lost in opening ; ani- mal not healthy, and weak, so as to be ill able to walk before the operation ; heart acted pretty well)—and a Dog. Phenomena: Donkey—Rhythm of motions ;—character of auricular actions ;—same, of the ventricular ;—double friction between heart and pericardium normally ;—eccentric impulse felt all over ventricles in systole ;—motions of cava. Phenomena: Dog—Normal double frictions of pericardium; —with other phenomena. S. 1. Rhythm of motions of the auricles and ventricles was as in former experiments ; first, the auricular systole, then im- mediately, the ventricular systole, without interval, and as if it were a continuation by undulation of the former motion. S. 2. Then the pause during which the auricle and ventricle became each distended and soft and flaccid, the former sliding its extreme margin downwards on the fundus of the ventricle toward the apex, to retract it suddenly again toward the sinus in systole,—and the latter protruding its apex and sides so as to be enlarged in every direction, except that of the trans- verse vertical diameter, to retract both apex and sides in the following systole, and at the same to rise upwards in its cen- tral parts with an impulse. S. 3. Before opening pericardium the condition of that sac was carefully observed, and it was noted, that while the peri- cardium remained stationary under all circumstances, the heart suffered much change in shape and size, so that there was in every part, and especially over the auricles, a to-and-fro motion of the cardiac pericardium on the external layer of that sac, a friction in one direction in systole and in the opposite in diastole. S. 4. The impulse before observed was obtained by the fin- ger applied to any part of the ventricle in systole. . 5. The cava observed, and a slight action was noted, viz. a diastole followed by a systole, the former with a wave-like sensation of motion from the heart downwards, and accompa- nying the auricular systole, and immediately preceding the ven- tricular. The separator above described was introduced into 192 REPORT—1840. the mitral aperture and a murmur was heard; but the heart ceased too soon, owing to errors in the insufflation, to allow of the experiment being properly followed out. OBSERVATION XIV. Same day. A Dog,small, and perhaps two years old, was poi- soned with prussic acid, and then prepared as usual. The heart acted pretty well for nearly half an hour. S. 1. The stillness or inertness of the free pericardium and constant succession of changes of shape and size in the heart were carefully observed ; the heart being, for the size of the animal, much larger than that of a donkey; the experiment was much less troublesome from that cause as well as from the greater facility of manipulation of a smaller animal. Every sy-- stole of the auricles produced a double friction, viz., one against the external layer of the pericardium and one against the fun- dus of the ventricles, or periphery of the auricular orifices ; and every diastole of course produced friction in the opposite directions ; and every systole of ventricle produced friction longitudinally from apex to fundus, and transversely from side to side, all round the body of the heart; while every ventricu- lar diastole included friction in the opposite directions. S. 2. The rhythm of the heart’s motions was as before, viz., first, the auricular systole,—and secondly, immediately there- after, the ventricular, and without marked interval, but, as if the latter motion were but a continuation of the former, by a sort of continued undulation,—and thirdly, the pause consisting first of auricular diastole, and then including the immediately suc- ceeding ventricular diastole, and interrupted first by the au- ricular systole. S. 3. Cava observed and motion noted, viz., a diastole fol- lowed by a systole, the former synchronous with the auricular systole, the latter immediately following. S. 4. The subclavian artery laid bare unintentionally for several inches, forming an arch more than two inches in length, and observed to lengthen without straightening in the systole of the heart, and to shorten slightly but sensibly in ventricular diastole. S. 5. As in every former distinct observation, the sensation of impulse was perceptible on every portion of the ventricular surface ; the shortening, rounding, hardening, and elevation of the central longitudinal axis, and increase of the transverse vertical diameter alone, of the body of the heart, easily distin- guished,—also the jerking over the orifices, &c., &c. 8. 6. The auricular systoleapparently audible, but the sound . ON THE MOTIONS AND SOUNDS OF THE HEART. 193 not separated by any very distinct interval from the instantly succeeding ventricular sound, which however it preceded ra- ther, and certainly preceded to the senses of touch and hearing together, the hardening and rounding of the ventricle. 8. 7. In the dog, as in the ass, the motions were slow com- paratively in the heart, auricles as well as ventricles. The right ventricle first, and afterwards the left ventricle, were punctured with a slender glass tube drawn out for a couple of inches at the lower end, and the result observed. In systole there was a sudden rise in the tube, and a slight subsidence in diastole. The subsidence was but slight, the greatest not being in the left ventricle more than half an inch, and in the right ventricle still less. The sinking of the blood in the tube in diastole was such as might be caused by a sudden withdrawal of an impulse sufficiently energetic (like that of the systole) to overcome gra- vitation abruptly, and so as to excite a jet in a tube containing a fluid column sustained by a constant pressure (such perhaps as might be produced by the venous influx) from below. S. 8. In both hearts the right cavities were relieved from distension before complete cessation of action, and the areas of the ventricles, judging by apparent extent of walls opened and spread out, seemed in no degree to differ. OxssERVATIONS XY. and XVI. July 18th.—Operated on two Donkeys of from four to eight months old. Phenomena : First donkey— Glass tubes introduced into left auricle and ventricle, and results noted ;—normal pericardial Srictions observed, and several other observations confirmed : Second donkey—Blunt hook and screw, successively interposed between mitral valves with considerable modification of first sound ;—also, spontaneous abnormal sounds ;—auricular SY- stolic sound ;—results of introduction of glass tubes into heart's cavities ;—confirmation of former observations. Woorara injected in each case; in the first, the operation very successful, but in the second, a second dose of two grains required. In the former, much blood lost, viz., probably owing to an accidental cut made in hastily opening the trachea for artificial breathing. The heart found acting rapidly, hurriedly, and with a rhythm unfavourable for observation. Second sound not di- stinct. The experiments intended were two, viz., stopping the mitral valves by an interposed blunt hook introduced through auricle, or by a screw-shaped wire similarly admitted; but owing probably to profuse hemorrhage, the first sound was not suf- VOL. Ix. 1840. o 194 REPORT—1840. ficiently normal for that experiment, and the second experi- ment was made, viz.— S. 1. Glass tubes drawn out at one extremity were pushed, with a rapid rotatory motion, into the auricle and ventricle of left side, and the column of blood observed. That in the auricle gave no satisfactory result, owing to sanguineous exhaustion apparently, and the consequent insufficient distension in dia- stole, and slight amount of contraction in systole in the auricle. But this much was noted, viz., that a very short column that filled the drawn out part, was not drawn in diastole, yet neither was it very strikingly lengthened in systole. ‘The ven- tricle gave better results, viz.,a column rose rapidly by suc- cessive stages, rising some lines at each systole, and continuing almost stationary at each succeeding diastole, and at length overflowing the tube and pouring over in large drops at each systole. S. 2. The friction between the heart and pericardium in systole and diastole of auricles and ventricles; the tension and jerking motion upwards in systole; and softening andsubsidence in diastole of the parietes of the ventricles ; the abrupt jerking over the orifices in systole, followed by subsidence in diastole ; the shortening of the diameters lengthwise, and transversely in systole; the immediate succession as by a continued undu- latory motion of the ventricular systole to that of the auricles; the sensation of an undulation from fundus to apex on the ven- tricles; the dimpling in systole of the left auricle (which only was observed); and the equality, post mortem cordis, of the two ventricles ;—all those former observations were repeated, and former results confirmed. OBSERVATION XVI. S. 1. The second animal's heart when exposed was acting with more regularity than the former, and the blunt hook and screw were successively tried. In each case material modifi- cations of the first sound were repeatedly produced by the in- terposition of the instrument between the valves in left interior — opening; but the modifications were not constant: and in no case was there any attempt made to impede the right interior valves. This much however was noted, that on several occa- sions the interposition of the instrument was followed by mur- — mur in the mitral opening with the systole, and by a more ob- tuse character of the first sound, and particularly by a want of sharpness of definition at its commencement. But it is to be added, that considerable irregularity existed for the greater part of the time in the sounds, viz., the first sound seemed ON THE MOTIONS AND SOUNDS OF THE HEART. 195 sometimes, and without apparent cause, more obtuse than others, and more short and abrupt, and the second was often wholly wanting or too indistinct for observation. S. 2. Further, there was observed a feeble dull sound, very short and rapid, synchronous with the left auricular systole, and somewhat anterior to the ventricular hardening, and up- rising, but scarcely separated by any distinct interval from the ventricular sound, and rather continued into it in a manner re- sembling the apparent passage of the auricular systole into that of the ventricle. S. 3. The glass tubes were in this experiment introduced as before, with similar results. Nothing striking occurred in that passed into the auricle, but a very short column being obtained, and that nearly stationary, owing probably to the auricle having been penetrated in several places by the hook and screw so as to suffer escape more readily by the other orifices. But the ventricle gave like results as in the former case, viz. a column rising in systole, stationary in diastole, and at length reaching the upper end so as to overflow. All the previously observed phznomena of the motions of the auricles and ventricles, in themselves and with respect to each other, and with respect to the pericardium, were confirmed on this subject, so that the description of those given under the head of the former expe- riment of this day, themselves but repetitions of former obser- vations, must be considered to apply to the normal condition without any important restriction or qualification. OssERVATION XVII. July 26th.— Phenomena: Dog—Distension to hardness of auricles during a torpid and as it were semi-paralytic state of ventricles ;—results of a prick in left auricle ;—proofs of active nature of auricular systole, and of negative character of ven- tricular and auricular diastole ;—of venous regurgitation du- ring auricular systole, and of equal size of both ventricles, &c.; —confirmation of other former observations. Subject, a Mastiff-terrier eighteen months old, poisoned —with prussic acid. S. 1. Heart acting regularly but rather feebly, though large and muscular; much distended and on both sides equally. Left ventricle and auricle both much dilated and the auricle quite tense with blood, so that the appendix could not contract for some time until a prick was made in it, when a jet was ob- served coincident with the systole. Some observers thought the jet synchronous with the systole of the ventricle ; but on placing the fingers in contact with the sinus and fundus ven- o 2 196 REPORT—1840., triculorum together, it was plain that the jet coincided with the auricular systole, and preceded by a fraction ofa second the ventricular systole. During the diastole of the auricles a slight shortening of the column, as from diminished impetus from be- low, occurred, and again, in auricular systole, a sudden length- ening of the column, to be followed again by a shortening in diastole. During the systole of the ventricles immediately succeeding that of the auricles, and without distinct interval, no increase of the jet or column occurred, and during the diastole of the ventricles no subsidence, but simply a shortening, as before described, immediately after the auricular systole. During great part of observation of the jet the left auricle was tense and hard almost to the finger, and nearly immove- able, and the ventricular action was dull and feeble, and the ventricles themselves were not fully emptied in systole, the heart appearing to have suffered considerable torpefaction from the poison. S. 2. A glass tube was introduced into the left auricle and ventricle in succession, but a clot soon forming, owing to es- cape of soda solution during the rotatory motion by which the glass was first introduced, no very decided result was obtained. S. 3. After the ventricles had become very feeble and even the left auricle become comparatively inert, some energy of contraction was observed in the right sinus, and with each con- traction a wave of regurgitation down the vena cava inferior, viz. a diastole of the vein immediately preceding the ventricu- lar contraction and coinciding nearly with that of the auricle, and followed by a systole coinciding with ventricular contrac- tion and auricular diastole. The auricles at no time acted with sufficient energy to promise any result from traction by a string, or to yield distinct sound in systole, owing to an extreme dis- tension of the cavities, attributable totorpor of the muscular sub- stance and rapid and copious supply of blood from the veins. S. 4. The ventricles after death seemed not to differ mate- rially in size, having been cut out before complete death, and allowed to contract. S. 5. Several previous observations confirmed on this occa- sion, viz. as to rhythm of motions and cavities ; viz. auricles and ventricles respectively acted exactly together, and the former immediately before the latter, and without distinct interval, but as by continued undulatory motion; elevation of central parts of ventricles in systole and subsidence in diastole ; fric- tions of the pericardium double with each pair of cavities, viz. both in systole and diastole. ON THE MOTIONS AND SOUNDS OF THE HEART. 197 OssERVATION XVIII. Phenomena: Tubes introduced into heart's cavities; results ; —confirmations of former observations asto rhythm, pericardial frictions, changes of shape in the heart, §c., §c.; compara- tive sizes of ventricles. July 50th.—Operated on a Dog between one and two years old by prussic acid. Heart acting feebly, with the normal rhythm however ; the cavities considerably dilated. S. 1. Glass tubes containing strong solution of carbonate of soda, secured during the introduction by corks temporarily fixed in the wide end, were introduced by arapid rotatory mo- tion into the right ventricle and auricle. Owing apparently to awkwardness in the manipulation, the result was not through- out uniform to the eye; but the general character of what was observed was this: Columns of blood rose into the tubes in every case, and were perceived to overflow in each case witha slight jet in the systole of the cavity penetrated, and a slight subsidence in the diastole. At one time, for a minute or two, without interruption, the tubes were observed to overflow steadily together, one being in left auricle and the other in right ventricle, each having a slight jet, or upward undulation, in the systole of the cavity containing it. This experiment was com- paratively very striking, owing to the great difference in colour of the two streams, viz. scarlet, and deep crimson or purple. During the whole observation nothing occurred suggestive of impulse, except of the impulse upwards of the systoles of cavi- ties, and the slight gravitation or subsidence in diastole ; and this latter, though often very distinct in each tube, was some- times quite imperceptible in either. No motion downwards in the tubes, such as suction would explain, was observed. 8. 2. After the observation the heart was cut out, and the _ left ventricle appeared rather larger than the right. _ 8. 3. The rhythm of the motions of the cavities; the auri- cular and ventricular double frictions of the pericardium ; the jerking upwards of the fundus and central parts of the ventricles in systole ; the shortening in systole; the stationary state of the heart amid all its changes of size and shape; the subsidence of the central parts and fundus in diastole, &c., &c., were noted to agree with former observations. OxsservaTions XIX. and XX. Aug. 5.—Operated by woorara on a Donkey two or three years old. Operation tedious, owing to strength and resist- ance of the animal. Also on a Dog. 198 REPORT— 1840. Phenomena: Donkey—Negative character of diastole. Dog—Apex cordis threaded and held tense in the direction of the mesial plane of the subject. Results: change of shape and size of the heart in systole and diastole, and visible mo- tions ;—glass tube passes into cava inferior ; results ;—columne carnee and parietes electrified ; results ;—cavities compared post mortem and found equal. 8.1. Glass tubes introduced into the left ventricle at fundus, and apex, and in each a column rose and at length overflowed, having a slight subsidence at each diastole, and sudden eleva- tion at each systole ; but no well-marked difference between the times of rise and fall in the tubes was detected. 8. 2. The heart acted for some time with considerable energy, notwithstanding great hemorrhage, but soon failed after being perforated. The heart was then cut out while yet contracting vermicularly, and electricity was applied so as to permeate the columnz and parietes, but no satisfactory action was obtained. The cavities of the heart had been for some time much dis- tended, from loss of irritability before excision. OBSERVATION XX. A Terrier-dog, stout though small, was then stunned by a blow on the head ; the chest was rapidly opened, and artificial breathing established. S.1. The apex cordis was then threaded, and at each sy- stole a pull at the chord was observed, followed by relaxation, and the tension and relaxation of the string alternated ; the former coinciding with systole, and the latter with diastole. (Note.—The string was drawn in the line of the longitudinal axis of the heart.) Dr. Boyd at one time kept the string firmly extended and permanently tense, by holding his hand as far away as the string would allow, for a short space, and then maintaining his position, but relaxing his hold so as to allow the string liberty to slide between his fingers when drawn away; and the result was, that before the experiment was suspended, an inch or more of the string appeared to have passed between his fingers, one eighth of an inch at least being pulled through at each systole. S. 2. After this observation had been made and repeated to the satisfaction of all parties, the heart acted still with much vigour, and both sounds were distinctly audible, notwithstand- ing great loss of blood. Also the diminution of the horizontal transverse and of the longitudinal diameter, and the increase of the vertical transverse diameter, with sudden bulging up- wards of the fundus and central parts, were very plain to the ON THE MOTIONS AND SOUNDS OF THE HEART. 199 eye in systole ;—while in diastole the subsidence of the central parts, with sudden increase of the horizontal cross diameter and of the long diameter, were equally striking. No tilting of the apex as an independent part was noted, nor any other motion than such as might be explained fully by the fixity of the fundus through the vessels, and the sudden increase of the cross vertical diameter in systole, causing an elevation of the longitudinal or central axis, which was most sensible at the apex or free extremity. 8.3. A glass tube was introduced into the cava with the termination directed towards the diaphragm, when a column of blood rose gradually without any jet until it reached the upper end nearly, when it ceased to advance, but continued stationary for some time, and at length receded slowly towards the middle of the tube. No sudden motion either upwards (as ex. gr. by auricular contraction) or downwards (as by dia- stolic suction) was observed. A gradual partial subsidence in the tube then followed, owing apparently to failure of impul- sive force in the moving powers of the venous circulation. S. 4. The heart was then cut out while yet contractile, and irritated by electro-magnetism and by pricking with scalpel, and to the satisfaction of every one present the columnz carnes were observed to contract and relax coincidently with the parietés. 8.5. The ventricles were equal in capacity to the eye and hand post mortem cordis. OssERVATIONS XXIJ. and XXII. August 8.—T wo Dogs operated on; one a stout terrier, the other a mongrel bitch, both eighteen months to two years old. Phenomena : Second dog—Glass tube introduced into cava ; results variable, with probabie causations of fluctuation ;—au- ricles cease action first ;—columne carnee irritated alternately with neighbouring paris of parietes, and results ;—confirmation _ of former observations respecting the mechanism of heart's action and the equality of the cavities during life. In the former animal the operation failed, owing to not hay- _ ing established artificial breathing in time. In the dog the following results were obtained. Having been prepared by stunning and tracheotomy, with a view to artificial respiration, the heart was exposed, and found beating with energy, exhibiting the usual motions and sounds. 8. 1. A curved glass tube was introduced into the cava in- ferior, and immediately a column of blood was observed, which, after ascending some way steadily, and during several beats of the 200 REPORT—1840. heart, again descended also steadily and during several beats. After a few moments, the tube being held upright with care, and the lower opening of the tube being toward the abdomen, and pressure being made on the tube through the parietes of the veins, a column of blood ascended slowly and steadily to the top of the tube and poured over at the top. Again, press- ure being withdrawn from the cava, fluctuation occurred, viz. irregular ascents and descents of the column, gradual and slow, and extending each of them over several beats of the heart, there being perhaps as many as half a dozen of each to each minute of the time they lasted. At no time was there any sud- den elevation or subsidence of the column, such as the auricular systole or ventricular diastole might be supposed to produce, supposing the latter to include suction towards the ventricles. The variations of level observed in the tube could be referred with any probability to nothing obvious, except the convulsive agitation of the right thorax, which was intact, and which heaved and collapsed violently for a short time, owing to a partial recovery of the animal from the stunning blow during the operation, in consequence of hemorrhage and artificially sustained breathing. ‘The tube was then introduced into the cava superior, and a column was observed in the whole length of the narrow part of the tube, and nearly an inch in height, and this column suffered no alteration either in systole or dia- stole. The shortness of the column in this case was owing ob- viously to exhaustion of the vascular system, or insufficiency of blood and of vascular tension. ‘There was not any respira- tory effort during this last observation. S. 2. During this last observation (on the cava superior) the unusual appearance was observed of complete quiescence nearly of the auricles, whilst the ventricles continued to act with con- siderable energy. The early death of the right auricle might be referred to withdrawal of supplies from the cava inferior especially; but that of the left auricle is not easily accounted for, since insufflation was duly persevered in. S. 3. The heart was cut out while yet contractile, and the columnz carnez of the right ventricle were observed to act accurately with the parietes, whether the stimulus were applied to the former or latter only. The columne of the left ventricle were become insensible to stimuli, and the parietes nearly so before the left was laid open for observation. S. 4. The elevation of the central cardiac axis, and espe- cially of its free extremity, viz. the apex cordis, was very con- spicuous in systole, and the opposite motions in diastole. Also the flattening and lengthening of the ventricles in diastole, and ON THE MOTIONS AND SOUNDS OF THE HEART. 201 rounding and shortening in systole. And after opening the ven- tricles the left seemed the larger of the two. The wave-like motion, or sensation as of an undulation from fundus to apex in systole, was very distinct. OxgsERVATION XXIII. August 24.—A Dog (bull-dog terrier), one to two years old, stunned, and chest artificially inflated. Phenomena: Results of threading different parts of the ven- tricles, and at the same moment pressing the threaded parts with the finger, and pulling at them by means of the thread, showing the mechanism of the heart’s throb ;—rhythm of cardiac and aortic pulsations ;—results of introducing a tube into the cava ;—respiratory suction ;—venous regurgitation in systole ; —phenomena of the heart’s action out of the body both as to motions and sounds. S. 1. The heart was laid bare and a thread was passed through the apex cordis, and a second through the parietes nearly over the mitral orifice, and traction was exerted on each string in a direction outwards, and away from or vertical to the point of insertion, and the result was that in each systole each string was felt to be pulled and rendered tense, and to become lax in diastole. At the moment of tension in each chord the _ finger was placed on the point at which each respectively had been introduced, and the result was a double sensation, viz. 1. That of traction in the chord, indicating contraction of the heart. and mutual approximations of its extremities, and, 2. that of outward impulse in the point of the parietes under the finger (indicating, as the Reporter conceived, the undulation of the blood reacting against the compressing parietes of the _ ventricles). ' 8.2. The attachments of the vessels or muscular parts in- serted into the roots of the arteries, especially the pulmonary artery, were observed very distinctly to approximate slightly towards the apex in each systole, and to recede from the apex in diastole. _ §.3. A barely perceptible difference in time was detected between the systole of the left ventricle and diastole of the aorta—no distinct interval however. 8.4. A glass tube was introduced into the lower cava, and a column of blood obtained, which oscillated frequently, but not in accordance with the heart’s motions. These oscillations were attributable (the Reporter conceived) to irregular, spas- modic, respiratory efforts, occurring in the right side of the chest, which was still air-tight, the mediastinum being still 202 REPORT—1840.° intact. The oscillations were sometimes short, and rapidly succeeded to each other with a rhythm not differing greatly from that of the heart, but at other times were protracted through several beats of the heart, viz. an ascent continued for several seconds successively, followed by a descent in the tube of similar duration. S.5. The pulsation of the veins was very distinct to the eye in systole, in both the pulmonary veins and cava; but whether owing to the auricular systole exclusively, was not examined into with sufficient care. This much was ascertained, that the visible venous action was a diastole coinciding with the commencement of the general action of the heart, and fol- lowed immediately by a systole. Neither diastole nor systole of vein seemed gradual, but abrupt and almost instantaneous. S. 6. A heavy curved knife was placed on the left ventricle and held erect between the fingers, so as to allow motion up- wards or downwards, and the result was as in former experi- ments, an elevation by sudden heave upwards of the knife in systole, followed by a subsidence in diastole with depression of the surface. S. 7. The heart was cut out while still beating, and con- tinued to beat in the hand regularly, with normal rhythm, for a minute or two, and notwithstanding being shifted from hand to hand amongst three observers. ‘The first sound was very distinct during the whole of the time, but less sharply defined at the commencement. It wanted likewise the jerking motion over the auri-ventricular openings, and the strong eccentric impulse or upward heaving in systole, and strongly-marked subsidence of the ventricle in diastole. The concentric motions and general rounding and shortening in diastole were very distinct. There was no second or diastolic sound. When cut open, the columnz carnez were seen to act along with the parietes. OBSERVATION XXIV. August 26 and 28.—Repeated the experiment on the con- traction of the abdominal muscles, as productive of a sound resembling the systolic sound of the heart, in the presence of Dr. Edwin Harrison, Dr. Hamilton Roe, Mr. Phillips, F.R.S., Mr. Gulliver, F.R.S., and Dr. Robert Boyd. The instrument employed was the flexible ear-tube or ste- thoscope, with which only the experiment is satisfactorily practicable, on account of the strong impulse attending the contraction, and the difficulty of distinguishing the acoustic from the tactual sensations it occasions. ON THE MOTIONS AND SOUNDS OF THE HEART. 203 The end of the instrument was placed in mediate contact with the abdominal parietes, and held firmly down upon the surface, with the intervention of a shirt and thick flannel under-vest; a strong and sudden expiratory effort was then made (in the manner described in the First Report of the London Committee) with the mouth and nostrils closed, so that a strong vibratory action, ending in firm tension of parietal muscles, was sensible to the subject of observation (the Re- porter), and likewise to the observers, and with this result, that a single loud, obtuse, abrupt, short sound was heard, and thought by every gentleman to resemble, more or less, the systolic sound of the heart. S. 2. The same experiment was repeated, with the addition of several folds of a silk handkerchief to the intervening sub- stances; and again, with a double fold of cloth and silk like- wise, in addition to the under-clothing above named, but without any important difference of result. S. 5. Hard substances also were interposed above the under-clothing, viz. a common framed school slate, and small bound books of different sizes; but no important difference was observed, except with the slate, through which the sound was considered to be decidedly less distinct than in any other form in which the experiment had been tried. In all these trials pains were taken to keep the cup of the stethoscope in accurate contact all round, through the substances interposed with the abdomen; and that was easily effected by the use on the part of the Reporter, who was the subject of experiment, of both hands at once in maintaining equable pressure. It is proper to mention, that several observers agreed in stating that similar sounds occurring to show in the cardiac i _ region, would be referred by them to the systole of the heart without any hesitation. _ Conctusions rrom BoTH SERIES For 1838-39 anv 1839-40. | Motions. | : Ist. That the order of the motions of the auricles and | ventricles is by continuous succession rather than by alter- nation of actions. The auricles contract abruptly after the Rest or pause, and the ventricles immediately after the auricles, without any distinct interval between the successive systoles. And the diastoles of the cavities follow in somewhat similar 204 REPORT—1840. order, viz. the auricular diastole coinciding with the ventri- cular systole, and continuing after it; the true Rest or pause being constituted by the diastole of the auricles and ventricles together, and in reality ceasing on the recurrence of the auri- cular systole. This rhythm of the motions seems to be uni- versal and common to cold- and warm-blooded animals. The only exception known to the Reporter from books or observa- tion, seems apparent rather than real, viz. an alternation of action, such as noted by Lancisi, for example, in the chick in ovo, and by several observers in cases of very rapid cardiac action. In such cases the diastoles have been so hurried and short, (owing no doubt to very rapid and copious influx from the veins,) that the systoles have been approximated to each other, and the intervening Rests have been apparently sup- pressed, and an apparent true alternation of systoles and dia- stoles without intervening Rest has been produced. 2nd. That the visible systolic and diastolic motions are first perceived at the bases or fixed parts of the cavities, viz. in the auricles at the sinuses, and in the ventricles at the fundus cordis; and that the apices of the auricles and ventricles (or free parts) are brought into full action after the other parts, and only just before the supervention of the opposite and next succeeding condition of the cavities, whether that condition be systole or diastole. 3rd. That in systole the heart is diminished in all directions (except only in such regions, or parts of the organ, as may have been previously collapsed or compressed during the un- resisting flaccidity of the diastole), and that its long axis in particular is strikingly and invariably shortened. 4th. That the normal systole of the auricles is energetic and almost instantaneous, and quite universal, the manifesta- tions of contraction in the appendix succeeding to those of contraction in the sinus, by a very minute interval; and that the auricular diastole is gradual, continuous, and wholly pas- sive, and is effected by an influx of blood from the cava pro- gressively distending the cavity from sinus to apex, and from the termination of one systole of the cavity to the commence- ment of the succeeding one. 5th. That the systole of the ventricles is gradual in its development, and complex in its phenomena; that those phe- nomena are partly attributable to contraction in the muscular parietes, and partly to resistance on the part of the fluids. By the muscular contraction the heart is made to compress the blood, which resists in all directions alike, and thrusts out ON THE MOTIONS AND SOUNDS OF THE HEART. 205 the depressed or collapsed parts of the ventricles, and favours the systolic shortening of the organ, and the closure of the auri-ventricular valves; and this reaction of the fluids mainly contributes, under various circumstances, to cause the motion that has been described as tilting of the apex; this tilting being principally, if not exclusively, a result of the elevation of the long axis of the heart in systole, owing to the assumption of a convex or globular form in the body of the organ, instead of its superiorly and inferiorly compressed state in the previous diastole. And the ventricular diastole or dilatation is wholly passive, exerting no influence over the venous current or arterial valves, and is effected by a rapid influx of blood from the veins, com- mencing at the moment of relaxation of the ventricles, and continuing until their succeeding systole, and reinforced imme- diately before the latter action by an abrupt discharge from the auricles. 6th. That the pulsations of the veins are of two kinds, at least in some animals, viz. both active and passive; and the latter or passive pulsations (which, on the authority of Haller especially, may be held to exist in all animals), are attributable to reflux from the auricles in their systole. 7th. The precordial throb or pulsation is caused, imme- diately, by the undulation of the blood in its resistance to sudden muscular compression in the systole of the ventricles. This reaction of the fluids is first perceived about the fundus of the ventricles, and last about the apex, towards which it seems to be propagated by a continuous undulation from the fundus with extreme rapidity. In consequence of this re- action of the blood, the heart’s sides are rendered convex, instead of compressed or flattened as in diastole, and are, in the middle parts more especially, heaved outwards from the central axis abruptly and with great force. Thus on all parts of the surface of the organ an impulse is felt in systole, which is greatest there, where, in addition to passive flaccidity of walls, there has been collapse in the diastole (viz. the central parts), and which is least where such collapse has previously been wanting or slight (viz. the apex). This cardiac impulse is usually perceived, in the healthy subject, over the apex only, owing to its being absorbed and neutralized over other parts of the heart by an interposed thick mass of spongy lung. The heart does not oscillate on the aorta, or move to and fro in the chest from systole to diastole, and vice versd ; nor does it suffer any changes in consequence of its own efforts, and exclusively of movements of the lungs and dia- 206 REPORT—1840. phragm, excepting in its shape and size, and in the thickness and tension of its parietes, and the capacities of its cavities. The doctrine, that the precordial pulsation is caused by a blow received by the ribs, in consequence of the heart’s “jumping” (ada, Hippocrates) or “striking” against them (‘ pectus ferit,” Harvey; ‘‘ costam ictu percutit,” Haller, &c. &c.), appears to be superfluous, with a view to explanation of phenomena (notwithstanding the ingenious illustrations of the ancient opi- nion by Senac and Hunter), and to be substantially unfounded in point of fact. 8th. That the arterial diastole or pulse, almost everywhere outside of the pericardium, perceptibly succeeds to the cardiac systole ; though near the heart, the interval between them is very brief, and to unpractised observers difficult to distin- guish. Sounds. 9th. That the first sound of the heart depends partly, but in a slight degree, on the abrupt closure and transitory ten- sion of the auri-ventricular valves, which give to this sound its sharp, well-defined beginning; but that the first sound is mainly attributable to cardiac muscular tension alone, and that its prolonged duration is probably owing to the progressive character of the normal systolic effort from fundus to apex; and that this sound is probably, in no degree or condition, attributable to any blow or stroke of the heart against the ribs. 10th. That the auricular systole is attended by an intrinsic sound resembling that of the ventricles, but more short, ob- tuse, and feeble. ‘This auricular systolic sound is often diffi- cult of detection, even on the naked heart, and with tolerably vigorous action of the auricles, owing to its being, to the inex- perienced ear, absorbed in, or masked by, the immediately- succeeding and vastly louder systolic ventricular sound. 11th. That the sounds of friction in pericarditis may, where well marked and under ordinary circumstances, be expected to be double at least, and they may be, not improbably, triple or more. In its systole, each cavity of the heart moves so as to cause a friction, in one direction, of its attached lamina against the adjacent free lamina of the pericardium; and in its diastole, a pericardial friction is caused by each cavity in an opposite direction; and as the auricles move to and fro in- dependently of the ventricles, the normal pericardial frictions must be quadruple, or double with the auricles and double with the ventricles. If, therefore, those frictions were ren- ON THE MOTIONS AND SOUNDS OF THE HEART. 207 dered sonorous by the interposition of any rough substance between the rubbing surfaces, (as lymph, for example,) and supposing the heart's actions sufficiently vigorous, under ordi- nary circumstances, we might anticipate with confidence a duplication of murmurs at least—one systolic and one dia- stolic ; and this must be the principal element in the acoustic diagnosis of pericarditis, since effused lymph may be of any thickness, consistence, extent, &c., and be situate on any por- tion of the heart’s surface between its nearest part and its furthest; and may therefore cause friction-sounds of the most variable seat, depth, and character. But, of course, another physical means of distinction of great importance remains, viz. the comparatively equable diffusion of the sounds of peri- cardial friction all around the place of attrition, rather than in any one exclusive direction. 12th. The sounds of the structurally-healthy heart are much liable to modification, by deviations from the normal standard in the state of the fluids and in the order and force and equa- bility of action of the carnez columne, and other contractile parts governing or influencing the action of the valves, and the closure and opening again of the orifices of the ventricles; and this dependence of the heart’s sounds on conditions dy- namic or material, wholly excluding structural defect, is so considerable, that the second sound may for a time be very variously modified or masked by strange murmurs, or even apparently suppressed in consequence of changes in the solids, of a purely dynamic character, and caused by humoral defect, in consequence of hemorrhage or from the introduction of poison into the veins. And the first cardiac sound, though never wholly wanting during the active existence of the heart, may still, under similar circumstances to those referred to, present various abnormal features; may, ea. gr., be as short as the second sound, or be attended or followed by anomalous murmurs, or be otherwise strikingly modified. 15th. Other conclusions, more or less satisfactorily de- ducible, as the Reporter conceives, from the facts stated, are,— That the peculiar sounds occurring in pericarditis, and attri- buted to pericardial frictions, are not referable only to vas- cular turgescence or dryness, &c. of the pericardium, but to lymph effused by, and adhering to, that membrane, or other equivalent obstacle to the easy and noiseless gliding over each other of the adjacent parts of the pericardium. 14th. That the ventricles are of equal capacity during life, and that the inequality usually met with after death is an illu- sion, as explained long since by Hervey. 208 REPORT—1840. 15th. That the suction-influence upon the venous circula- tion, attribuied to inspiration by various writers, is well founded. 16th. That the action of the long muscles, and more espe- cially those of the abdominal parietes, is attended with an in- trinsic sound. The notice of this fact by the Reporter has been rendered necessary in consequence of some attempts at verification, and some criticisms on an Experiment of the London Committee for 1837-38, published in the last edition of Dr. Hope’s very valuable work on the Heart. 17th. That the sounds of the heart, like the motions, are governed by the same law in all warm-blooded animals hitherto examined, and probably in all kinds whatsoever in which car- diac sound occurs, viz. that the first sound in all animals is relatively longer and obtuser, and the second shorter and sharper ;—that those sounds are, as in the human heart, respectively systolic and diastolic; that their causation like- wise follows the same law as those of man, the first sound being mainly muscular, and the second probably exclusively valvular ;—likewise, that there is the same causation and mutual relation of the cardiac and arterial pulsations. JouHn CLENDINNING, M.D. Oxon. and Edinb., Fellow of the Royal College of Physicians, Vice-Pre- sident of the Royal Medical and Chirurgical Society, and Physician to the St. Marylebone Infirmary. > = =. h , 209 An Account of Researches in Electro- Chemistry. By Pro- fessor SCHOENBEIN, of Basle. Tue British Association for the Advancement of Science, at their last meeting in Birmingham, honoured me with the charge to undertake a series of experiments, with the view of extend- ing the limits of our knowledge on the connexion which is sup-~ posed to exist between electrical and chemical phzenomena. The memoir which I now take the liberty to lay before the Association contains an account of the results of my late inves- tigations, many of which may perhaps appear as not immedi- ately bearing upon the subject in question; but I think them, nevertheless, closely connected with it. I must, however, not omit to say, that my task is still very far from being accom- plished. It is familiarly known, that a peculiar odour, resembling that of phosphcrus, is developed whenever common electricity passes from metallic or any other conducting points into at- mospheric air; but I am not aware of having seen it anywhere _ Stated, that a similar odour is disengaged during the électro- lysis of water, though there can be no doubt that, besides my- self, more than one philosopher has observed that phenomenon. The complete ignorance in which we still remain of the true cause of the electrical smell, and of the appearance of the latter under circumstances apparently so different from each other, cannot fail to excite scientific curiosity to a high degree, and stimulate philosophers to employ all their experimental means and mental powers to clear up the mysterious phenomenon. My own endeavours to solve the problem have been manifold, and for a long time were fruitless ; at last, however, I sue- ceeded in ascertaining some facts which promise to throw light upon the subject in question. Respecting the disengagement of the electrical odour during the electrolysation of water, as well as during the passage of common electricity from points into atmospheric air, my researches have led ‘to the following results :— 1. The peculiar smell makes its appearance as soon as the electrolysation of water begins, and continues to be perceived for some time after water has ceased to be decomposed. 2. The phosphorus smell is produced at the positive elec- trode only, and under no circumstances whatsoever at the 1840. P 210 REPORT—1840. negative one; for when the gases resulting from the electro- lysis of water are received in separate vessels, the smell is perceived only in that which contains oxygen. 3. The odoriferous principle can be preserved in well-closed vessels for a great length of time, whether mixed with oxygen or with detonating gas. 4. The disengagement of the smelling substance depends— (a) Upon the nature of the positive electrode. (b) Upon the chemical constitution of the electrolytic fluid, and (c) Upon the temperature of that fluid. With regard to the circumstance mentioned under (a), my experiments have shown that it is only well-cleaned gold and platina which are capable of disengaging the odoriferous prin- ciple. The more readily oxidable metals, as well as charcoal, do not possess that property at all. It is worthy of remark that iron, though acting (agreeably to my former experiments) like gold and platina when perform- ing the function of the positive electrode, does not permit the disengagement of the odour. As to the condition mentioned under (4), I have ascertained that the odoriferous principle is obtained from distilled or com- mon water when mixed with chemically pure, or with common sulphuric acid, with phosphoric acid, nitric acid, potash, and a series of oxi-salts. I could not get a trace of it from aqueous solutions of chlorides, bromides, iodides, fluorides, hydro- chloric acid, hydro-bromic acid, hydriodic acid, hydro-fluoric acid, sulphate of protoxide of iron. If to the fluids (above mentioned), which permit the disengagement of the peculiar smell, small quantities of nitrous acid, iron vitriol, proto- chloride of iron or of tin are added, not the least portion of the odoriferous principle will be given out, however actively water may be electrolysed. With regard to the aqueous solution of potash, I have observed the curious fact, that the smell is some- times disengaged from it and sometimes not, the latter case occurring much more frequently than the former. I do not know yet the cause of that anomaly. Concerning the influence which temperature exerts upon the development of the peculiar smell, I have found that a fluid from which the odoriferous principle is abundantly disengaged at a comparatively low temperature, does not yield a trace of it when heated near its boiling point. I must not omit to state, that dilute sulphuric acid is the fluid best fitted for producing the smelling substance, and making the experiments which this memoir refers to. It sometimes happens, however, that even RESEARCHES IN ELECTRO-CHEMISTRY. 211 in making use of that fluid, the disengagement of the cdorifer- ous principle is either suddenly stopped or does not take place at all. In such cases, the surface of the positive gold or platina- electrode is not pure, ?. e. it is covered with some foreign sub- stance; and to cause the reappearance of the peculiar smell, it is necessary to clean that electrode, which, by my experience, is best done by washing it first with pure muriatic acid, and after- wards with distilled water. 5. If some pinches of powdered charcoal, iron-, tin-, zinc-, or lead-filings, or of powdered antimony, bismuth, and arsenic, or some drops of mercury are thrown into a bottle containing the odoriferous principle (mixed with oxygen), the peculiar smell disappears almost instantaneously. Iron and charcoal seem, however, to act more rapidly than the other substances men- tioned do; gold and platina, when strongly heated, also destroy the smell. Small quantities of nitrous acid and aqueous solu- tions of proto-chloride of iron, sulphate of protoxide of iron, and proto-chloride of tin, being put into a vessel containing our peculiar principle, do likewise instantaneously annihilate the phosphorus smell. 6. A gold, or platina plate, after having been kept only for a few moments within a vessel containing the odoriferous prin- ciple (mixed with oxygen), appears to be negatively polarized. To excite that polar state in the metals mentioned, it is a con- dition, sine gua non, (a) That the surface of the plate of either metal be abso- lutely clean and entirely free from moisture. (b) That the temperature of the metal be comparatively low. Heated gold or platina do not assume the negative polar con- dition. The current produced by such a polarized metal is of so short a duration, that it may be considered as instantaneous. Among the metals more readily oxidable than gold and platina, it is only silver and copper that are rendered negative by being put into an atmosphere of the odoriferous principle; but the degree of polarity acquired by these metals is exceedingly slight. 7. Gold and platina having been polarized in the manner in- dicated, maintain their peculiar condition for some length of time when placed in common air. I have found plates which had been exposed to the atmosphere, at least for a couple of hours, still perceptibly negative. 8. A polarized stripe of gold or platina loses, almost instan- taneously, its negative condition, when plunged into an atmo- Sphere of hydrogen. If the metal is kept in hydrogen longer than just required for destroying its negative polarity, it as- P2 22 REPORT—1840. sumes, according to my former experiments, a positive con- dition. It will hardly be necessary to mention, that heat also destroys the polarity in question. 9. Oxygen obtained by the electrolysis of water, and deprived of its peculiar smell by the means indicated under § 5, has alto- gether lost its power of rendering gold and platina negative, and is, in a voltaic point of view, as inactive as oxygen prepared in the usual way. Phenomena of Polarization caused hy common Electricity. 10. A gold or platina plate, having a perfectly clean and dry surface, assumes negative polarity when exposed to the action of a positive electrical brush issuing from a metallic or any other conducting point. The longer the brush is playing upon the surface of the metal, the higher will be the degree of polarity acquired by the gold or platina. A small platina stripe, after having been exposed to the action of a brush produced by thirty turns of my electrical machine, deviated the needle of a delicate galvanometer by 60°; sixty turns, under the same cir- cumstances, caused a deviation of 90°. It seems that the nature of the metal which performs the function of a point of emission also exerts some influence upon the degree of polarity acquired by gold and platina. Ceteris paribus, a point of emission consisting of gold caused a deviation of 170°, a point of brass only one of 60°. As to the metals (more readily oxid- able than gold or platina), I have only succeeded with silver and copper in polarizing them negatively by common elec- tricity. The degree of polarity acquired by the last-mentioned metals is, however, also exceedingly slight. 11. The negative electrical brush produces exactly the same voltaic effects as the positive one does. 12. A platina plate, polarized either by the positive brush or by the negative one, loses its electro-motive power when plunged only for a few moments into an atmosphere of hydro- gen. All the remarks made under § 8 also apply to the case in question. 13. If gold or platina plates are connected with the prime conductor of an electrical machine, 7. e. made points of emis- sion, they will not assume any polar condition, however long and lively a brush may have been issuing from them. 14. Heated or moistened gold, or platina plates, cannot be polarized by the electrical brush. 15. If the points of emission are heated or moistened, the electrical brush issuing from them has no longer any polarizing power. It was impossible to excite in gold or platina even the RESEARCHES IN ELECTRO-CHEMISTRY. > 41153 slightest degree of negative polarity by holding these metals ever so long against a brush issuing from heated or wetted points. 16. The electrical brush proceeding from heated or moistened points does not produce the well-known phosphorus smell. The easiest way of depriving the brush of its smell is to cover the point of emission with a piece of moistened linen. Now in what manner are we to account for the facts above stated, and what are the inferences to be drawn from them ? As to the smell being developed at the positive electrode during the electrolysation of water, we can hardly help drawing, from the experiments mentioned in the first section, any other conclusion than that it is due to some gaseous substance dis- engaged (conjointly with oxygen) from the electrolytic fluid by the decomposing power of the current. But what is the nature of that substance? Is it elementary or compound? With regard to its voltaic bearings, it exhibits the strongest analogy to chlorine and bromine; of which bodies I proved, some time ago, that they possess, toa high degree, the power of negatively polarizing gold and platina. I have also formerly shown, that these metals lose again their negative polarity acquired under the influence of chlorine and bromine, when plunged into an atmosphere of hydrogen; there is, consequently, not the least doubt that, as to its electromotive power, the odoriferous prin- ciple bears the closest resemblance to chlorine and bromine. Now, does not this great analogy between the voltaic properties of chlorine, bromine, and our smelling principle, speak in favour of the supposition, that these three substances belong to the same class of bodies, 7. e. to those which Berzelius called ‘halogenia’? If we take into further consideration the facts, (a) that most metals destroy the peculiar smell, that is, com- bine with the odoriferous principle in a direct manner, and even at a low temperature; (4) that the said principle is not dis- engaged at the positive electrode, unless the latter be composed of gold or platina; that is to say, of an eminently electro- negative metal ; (c) that the odoriferous body is not eliminated by the current, if the electrolytic fluid happens to contain a substance having a strong affinity for oxygen, for instance, sul- phate of protoxide of iron; and (d) that our peculiar principle is always set free at the positive electrode, and never at the negative one; I say, if we duly consider all these facts, we can hardly help drawing from them the conclusion, that the odori- ferous substance is a body very like chlorine or bromine. The odoriferous principle, however, may perhaps be nothing but a secondary result of the electrolytic action. Such is no doubt 214 REPORT—1840. possible, and indeed it was the first view I took of the case. The following reasons, however, seem to speak against the cor- rectness of such a supposition. As chemically pure water (or what we take as such), mixed with sulphuric, nitric, and phos- phoric acids, with potash and many oxi-salts, yields the odori- ferous principle, we must conclude that the latter proceeds from water, and not from the other substances. Now what secondary product does water allow to be formed at the positive electrode? The oxygen being eliminated at the latter, might certainly combine with some water, and produce peroxide of hydrogen. But this compound is not gaseous at the common temperature, and its vapour is wholly inodorous. I have be- sides observed, that platina enveloped with a film of peroxide of hydrogen, is positive to common platina. From these facts it follows, that the odoriferous principle cannot be peroxide of hydrogen. Or does another perhaps exist, consisting of hydro- gen and oxygen, and containing more of the latter element than the peroxide does? Are perhaps even chlorine and bro- mine compounds of a similar description? The peroxides of manganese, lead, and silver, exhibit the same voltaic properties as chlorine and bromine, both groups of bodies being emi- nently electro-negative. Such a strong analogy, does it not indicate a similarity as to their chemical constitution? I do not venture to answer any of these questions. ‘The present state of chemical science does not yet warrant us to speak of chlorine and bromine as of compounds, and I shall therefore consider the odoriferous principle as an elementary body, and call it “‘ Ozone,”’ on account of its strong smell. Now if we take it for granted that ozone is an elementary substance, and knowing that it originates in water, we must conclude that this fluid is made up of two electrolytes, one consisting of hydrogen and oxygen, the other of ozone and some electro-positive body. When a current is made to pass through such a fluid, both electrolytic compounds are decom- posed, their anions, oxygen and ozone, being evolved at the positive electrode, their cations at the negative,one. As to these cations, we know well enough that one of them is hydro- gen. But is ozone also, like oxygen, united with hydrogen? All the experiments I have hitherto made with the view of dis- covering in the gas evolved at the negative electrode something besides hydrogen, have led to negative results, a circumstance which seems to prove that ozone, as met with in water, is com- bined with hydrogen. I do not, however, yet consider this point as definitively settled. That (what we call) pure hydrogen is capable of ren- RESEARCHES IN ELECTRO-CHEMISTRY. 215 dering gold and platina electro-positive, seems to me so extra- ordinary and so important a fact with regard to the chemical theory of galvanism, that I cannot but recommend it to the full attention of philosophers. Why indeed should a piece of platina, being surrounded with a film of hydrogen, and vol- taically associated with common platina, produce a current when plunged into pure water? Which is the chemical action that possibly can take place under such circumstances? Ac- cording to the present state of our chemical knowledge, it is very difficult, if not impossible, to give a satisfactory answer to that question. Has perhaps all the hydrogen hitherto pre- pared not been chemically pure, and does it always contain a principle still more electro-positive than hydrogen itself, that is, having a greater affinity for oxygen than hydrogen has? Careful experiments alone can decide these important points. The fact above stated, that ozone is not developed at the positive electrode, unless the latter be either of gold or of pla- tina, is, in my opinion, very easily accounted for. These metals having, at the common temperature, very little affinity for ozone, do not combine with it, any more than they do with oxygen in the same circumstances, whilst the other metallic bodies readily unite with the odoriferous principle*. At a high temperature, gold and platina appear to be capable of combining with ozonef ; and this property seems to account for the fact, that from heated dilute sulphuric acid, for instance, the smelling substance cannot be disengaged. It is, however, possible that ozone, in the moment of its being eliminated by the current, reacts upon the heated water, combining with the hydrogen of the latter. The fact that no ozone is set free if the electrolytic fluid happens to be mixed with some readily oxidable substance, with iron-vitriol, for instance, seems to depend upon a decom- position of water, the oxygen of the latter uniting with the protoxide of iron, and its hydrogen with ozone. The non- appearance of the latter is indeed very easily understood, if we suppose its action to be entirely analogous to that of chlorine and bromine. Before proceeding to the discussion of other facts, I must say a few words on the polarizing influence exerted by ozone upon gold and platina. In former papers I have endeavoured to prove, experimentally, that certain voltaic conditions which some metals (placed under given circumstances) seem to assume, are not to be considered as real modifications of those metals themselves (a view still maintained by some philosophers), but * See § 5. t Ibid. 216 _ REPORT—1840. as changes proceeding only from certain substanees being in some way or other deposited upon those metallic bodies. If, for instance, platina becomes positively polarized in an at- mosphere of hydrogen, and negatively in one of chlorine or bromine, that metal itself does not undergo the least change with regard to its natural voltaic properties; and it is only the film of hydrogen or chlorine that surrounds the metal, which is to be considered as the seat of the electromotive power, or as the cause of the polarity. Exactly the same remarks apply to the negative polarity which gold and platina seem to assume when put into an atmosphere of ozone. By a sort of capillary action that substance adheres to the metal, and the latter being voltaically associated with another piece of the same metal (in its natural state) and plunged into water, the latter will be acted upon by ozone just in the same manner as under similar cir- cumstances it would be by chlorine or bromine. The film of ozone covering the platina will unite with the hydrogen of water, and produce by that action a current. This current will last until all the ozone adhering to the platina stripe unites with hydrogen, but the quantity of that principle being exceedingly small, the duration of the current cannot be long. Having fully developed my views on the chlorine and bro- mine circuits in the Philosophical Magazine (August, 1839), and everything said there applying to an ozone arrangement, I have no occasion to enter into further details respecting this branch of the subject. As to the depolarizing action which an atmosphere of hy- drogen exerts upon gold and platina when negatively polarized by ozone, it perhaps may depend upon the combination of the latter with hydrogen. In order to account for the disappear- ance of the polar state, it is, however, not necessary to pre- sume the taking place of such an action. As platina becomes positively polarized by hydrogen, and negatively by ozone, it is obvious that the opposite voltaic actions of these two elements must, under certain circumstances, exactly balance each other. It is manifest that the facts considered throw a new light upon what is usually termed negative voltaic polarization. The results which I obtained some time ago on that subject are pretty generally known. They seemed to prove that the nega- tive polar state assumed by the positive electrode in water (holding oxi-acids dissolved) is due to a film either of oxygen or of peroxide of hydrogen. ‘To the same cause I was inclined to ascribe the negative polarity excited in that portion of aci- dulated water which is near to, or in contact with, a positive electrode. From the facts above stated, it now appears that, in RESEARCHES IN ELECTRO-CHEMISTRY. 217 both cases, the negative polarity results from the presence of ozone. Indeed water charged with that principle is negative to pure water, whilst the same fluid holding oxygen dissolved is, in a voltaic point of view, inactive to pure water. Water mixed with some peroxide of hydrogen bears to common water the same voltaic relation as zinc does to copper. Without having recourse to actual electrolysation, we may indeed pro- duce, by means of insulated ozone, all the phenomena of nega- tive voltaic polarization, a fact which seems to prove the correctness of the explanation offered of the phenomena in question. I also suspect that the peculiar condition of iron, or its in- active state, has something to do with ozone ; but for the pre- sent I cannot enter into that subject. It is now time to speak of the phenomena of polarization produced by the agency of the electrical brush. On comparing them with those called forth by ozone, we cannot but perceive a strong analogy between both series of phenomena. The very same metals which become negatively polarized by ozone, are brought into a similar state by the action of the electrical brush. The same conditions to be fulfilled, in order to polarize gold and platina by ozone, are likewise requisite to render these metals negative by the agency of common electricity. The negative polarity developed by ozone is destroyed by the same means by which we annihilate the negative poiar state called forth by the brush. These facts are sufficient to coun- tenance the conjecture, that the cause of the negative polarity is in both cases the same, z.e. that it is a film of ozone sur- rounding the metals. I have stated (§ 16) that the brush can easily be deprived of its peculiar smell, and that by so doing the former loses its polarizing power. ‘This fact clearly proves that it is not the electrical brush or discharge itself _ that excites in the metals exposed to its action the negative polar state, but the odoriferous principle accompanying the brush. This principle affecting our olfactory nerves precisely in the same manner, and also producing the same voltaic effects as ozone does, are we not entitled to infer that the smelling matter in the electrical brush and the odoriferous principle evolved at the positive electrode, are identical bodies? It ap- pears to me that they are, and I do not, therefore, hesitate to ascribe the familiar electrical odour to ozone. _ But how does it happen that ozone makes its appearance, whilst common electricity is passing from the points of a charged conductor into the atmosphere? To account for such a remarkable fact, we certainly must suppose that there is an 218 RruPoRT—1840. electrolytic compound present in the air, as well as we suppose one to be contained in water, and that the electro-negative con- stituent, or the anion of that electrolyte, is our ozone. The passage of electricity from the points of charged bodies into the surrounding air being in fact nothing but the act of the restoration of a broken electrical equilibrium, or a current, it is not difficult to conceive how ozone is set free near the points of emission. Our supposed electrolyte being present in the atmosphere, requires only to be placed within the circuit of such a current in order to be electrolysed, or to have its anion, ozone, separated from its cation. If all these suppositions be correct, it follows that the electrolysis of our ozonic compound will be most vigorous where the emission of electricity is most abundant, and that consequently, at such a spot, the strongest smell of ozone will be perceived, and platina or gold acquire the highest degree of negative polarity. Now experiments prove that such is really the case. That the peculiar odour perceived when any terrestrial ob- ject is struck by lightning has something to do with ozone, cannot be doubted. We have been hitherto profoundly igno- rant of the nature of that odour, and everything said and conjectured about it by ancient and modern philosophers must, in my humble opinion, be considered as totally unfounded. We know the fact only, and nothing more. The smell pro- duced by lightning is usually described as being either sul- phureous or phosphorous. Twice in my life I had an opportunity to observe this odour, once in the church of my native place (Mezingen in Wurtemberg), many years ago, another time in my own house at Basle, only last summer. The second case being still fresh in my memory, I shall say a few words about it. The object struck by lightning was a small chapel situated on the middle of the bridge of the Rhine, and about 200 yards distant from my lodgings. Immediately after the stroke had taken place, not only my house, but also the houses of my neighbours, were filled with a bluish vapour, and a pungent smell was perceived. Six hours after the occurrence I entered into a parlour which had not been opened all the day, and I could still perceive the peculiar odour. My testimony is cer- tainly not wanted to establish the fact, that lightning always causes the disengagement of an odoriferous principle; but I think that, on account of the great mystery which is still hang- ing over that phenomenon, the number of observations and statements about it cannot be too much increased. The fact — related offers, besides that peculiar interest, that the smell was perceived at a comparatively great distance from the object RESEARCHES IN ELECTRO-CHEMISTRY. 219 struck by lightning. As far as my observations go, they in- cline me to consider the odoriferous gaseous substance set at liberty by the agency of lightning as ozone. Lightning being the same phenomenon on a large scale as the electrical spark or brush is on a small one, and our supposed electrolytic com- pound penetrating the whole atmosphere, electrolysis must take place, and consequently ozone be disengaged to a con- siderable amount, as often as lightning crosses our atmospheric air. The assertion of some observers, that the odour is of a sulphureous kind, and the statement of others, comparing it with the smell of phosphorus, may easily be reconciled to each other; for I have remarked that ozone, when somewhat con- densed, is rather pungent, whilst the same substance mixed up with a large quantity of air, possesses a phosphorus smell. It is well known that the generality of people call any pungent odour sulphureous. Hence, if it happens that the odoriferous principle set free by lightning reaches the observer in a con- densed state, he will describe it as sulphureous, but like phos- phorus when inhaled mixed up with a good deal of air. Hence it follows, that the nearer the observer happens to be plaeed to the spot where a stroke of lightning takes place, the more pun- gent will be the smell perceived by him. ‘The property of pla- tina to assume negative polarity in a medium containing free ozone, seems to offer an excellent means to ascertain the pre- sence of that principle in the atmosphere. It appears, there- fore, to be desirable to make experiments on that subject, and to place, for that purpose, platina stripes (not being insulated) in elevated regions, particularly on days when thunder-storms are taking place. Before closing this paper, I must not omit to put a question of some importance. Does the electrolytic compound men- tioned exist in our atmosphere quite independent of its aqueous vapour, or is it (the electrolyte) carried into the air by the eva- poration of water? It is a matter of course, that this question can only be answered by experiments, and I have not yet found time enough to make them. Supposing the electrolyte to be ‘earried into the atmosphere by the evaporation of water, the electrical brush should not produce any smell when passing into absolutely dry air, and the quantity of ozone disengaged would, ceteris paribus, be proportional to the quantity of aqueous vapour present in the atmosphere; 7. e. would depend upon the hygrometric state of the latter. It is hardly necessary to say, that problems of the highest scientific importance would be raised, in case it should turn out that ozone can be produced in dry air. Be that, however, as it may, the ubiquity of our elec- 220 REPORT— 1840. trolyte can hardly fail acting a most important part in the household of nature; and it is not impossible that the elec- trical phenomena taking place within our atmosphere, the real cause of which is still covered in darkness, are closely con- © nected with the workings of our presumed compound. The fact of philosophers having not yet had the slightest notion of the existence of such a body is, I presume, no argument against its existence. If we suppose the electrolyte in question to be a substance closely resembling water in its chemical and phy- sical properties, and existing in the latter fluid as well as in the atmosphere, only in very small quantities, it is easily conceiv- able why its existence has not hitherto been observed. I readily allow, however, that many researches, many experi- ments, must still be made before we arrive at certain results, at complete certainty, regarding the subject of ozone. Convinced as Iam of its great scientific importance, I shall not fail de- voting all my leisure time to its close investigation, and to sifting a matter to the bottom which promises to yield so rich a harvest of results. I should feel indeed very proud, if the British Association would honour me with the charge to pre- sent them an account of my researches next year. It would be not right if’I did not expressly state, before finishing my paper, that I owe most of the results above men- tioned to a pile constructed upon my friend Mr. Grove’s prin- ciple, an arrangement which cannot be too highly thought of. C. F. ScHONBEIN, Bale, August 2, 1840. Second Report upon the Action of Air and Water, whether fresh or salt, clear or foul, and at various temperatures, upon Cast Iron, Wrought Iron, and Steel. By Roserr Mauer, M.R.I.A., Ass. Ins. C. E, 140. Since my former report upon this subject was submitted to the British Association, as now printed in its Transactions, additional interest and importance has been given to every branch of the inquiry, as to the durability of iron under its various circumstances and conditions, by the rapidly-increasing introduction of iron vessels to navigation in the most difficult and lengthened voyages. Amongst the several problems of a strictly scientific cha- racter requiring solution before the use of iron ships for distant voyages, or their economic adoption, under any circumstances, can be pronounced ¢ertain, is the great question of their dura- bility as compared with those of timber; and it is hoped that the experiments made or in progress under the auspices of this Association, and about to be detailed, will render, in part at least, a satisfactory reply thereto. But, besides the desirableness of prolonging the existence of iron ships, it is of the utmost importance to prevent the formation of rust at all upon them under water, which, once produced, affords a *nidus’’ for the growth of marine animals and plants by which the ship’s bottom is rendered foul, and her sailing qualities are greatly interfered with. These causes of foulness are found to adhere with the utmost obstinacy to the oxidized iron. It is part of our object to endeavour to find remedies for these evils. 141. The present report contains the first set of tabulated results which I have obtained as to the amount and nature of corrosion of cast and wrought iron under several different con- ditions of exposure to the chemical action of air and water, whether of the ocean or of rivers, &c. And as this subject essentially consists of two distinct parts, or is to be viewed in two different lights, namely, as a chemical or purely scientific inquiry, and as a technical one, from which useful practical results are to be derived, and as some portions of it, viewed in the former light, are still under experiment, and likely to be so for some time to come, I purpose, on this occasion, to reserve the purely scientific consideration of the subject, as far as pos- BAS REPORT—1840. sible, for a future and final report, and confine the present to the results and their modifying conditions which have already been obtained, and are of practical value and importance to the civil engineer, the iron founder, or the iron-ship builder. 142. I proceed, then, to state the general nature of the ac- companying tabulated results of experiment. The first five tables contain the data and results of the chemical or corroding action of sea and fresh water on cast and wrought iron under five several conditions of experiment, continued during a period of between a year and thirteen months. It will be seen that these five first tables, so co-ordinate with each other as to form one connected and comparable whole, by — which have been determined the relative rates of corrosion, and the absolute amount thereof, for eighty-five several sorts of cast and wrought iron, under each of the following conditions, viz. 1. In clear sea water, at temp. 46° to 58° Fahr. TI. In foul sea water, ai 46°. Din III. In clear sea water, a 1 a a IV. In foul river water, ,, 36%, 5 selene V. In clear river water, 5, a 3 aati 143. During the period in which the several sets of speci- | mens have been immersed, the five waters acting on them have been examined as to their physical and chemical properties. 144. The water of No. 1, that of Kingstown Harbour, con-— tains, in a cubic foot, 12661 grains of solid matter, which — analysed with precaution in the usual manner, had the follow-_ ing constitution reduced to per cent. : Chioride sodium... .. se + isi ney F832 Chloride magnesium . - + + + 10°79 Bromide magnesium - - + = - 0°60 Sulphate lime. . +. -(* s+ «+ + 4:87 Sulphate magnesia. - + + + = 5°30 Ganhatiate UuMeis..)ena>Sastasdor seed aaa Organic matter. - + + + 8 + 5:27 The Arc acd om’ dstaleante cule a acu Grads 100°00 I could not detect any chloride of potassium or carbonate iron, said to be occasionally present in minute quantity in sea water. The amount of organic matter is very variable. It therefore appears not to differ much in composition from the waters of the British Channel, but considerably from those of the Mediterranean and the Atlantic Ocean, as given in the best ON THE ACTION OF AIR AND WATER UPON IRON. 223 published analyses*. Its specific gravity is = 1027:80; and 100 cubic inches of the water taken from the surface contain, in combination, 1:43 cubic inch of gas, which proves to be atmospheric air, with traces of carbonic acid, or about one volume in seventy. This water is beautifully pellucid, and free from suspended inorganic matter. Its boiling point in glass is 214°5 Fahr., barom. 29-7 inches. 145. The following table of the amount of saline contents of sea water, from various localities, may be interesting, as bearing upon our subject :— Table of Saline Contents in 1000 parts of Sea Water. Authorities. meretic mica 27/202 9, Ae, 28°30 Marcet. Arctic Seasea water . . 3°50 Worth Atlantie “oy 5~ 5 42°60 Equator Bacal Sekar nek RM A Ti Bauch Atlantic el ei) ) kee 41°20 39 33 39 39 Prediterraneanr®” "8400 ven | ray 39°40 Laurent Seaof Marmora. . . . ., 42-00 Marcet. etek Wea Fry ie Ans Uy 21°60 39 3) Rear © I Ly ody: Se toasters 6°60 tera reat). vegies Asti Ylang beaag “fe British Channel . 2... , 35°50 Sweitzer. ° enn ects WON. Pinsshtoga: 0s 33°76 Mallet. 146. One thousand volumes of sea water are stated, on the authority of Laurent, Bouillon, and Lagrange, to contain 62 volumes of carbonic acid. I have never been able to find as much. Dr. Marcet also states that ammonia is occasionally present in it. 147. The water of No. 2, or that of the foul sea water, taken from the mouth of the great Kingstown sewer, is found full of putrid organic matter of a black and white colour, exhales an intolerable foetor, and is permanently milky or opalescent. A cubic foot of it contains 1379°5 grains of solid matter at a Minimum, and varies, up to the full saline contents of the sea ‘Water, according to the degree of dryness of the weather, and Consequent greater or less admixture of fresh water. The Water in sitw constantly evolves bubbles of hydrosulphuric acid and pond-gas = (H, C), of which torrents may be ob- tained by stirring the mud at the bottom; its solid constituents are the same as those above given for the sea water of the har- bour, with a very variable proportion, however, of carbonate and sulphate of lime and of chloride of calcium, derived from the fresh water which mingles with the salt. It holds, com- * Marcet, Laurent. Q24 REPORT—1840. bined, one volume in thirty-six, on the average, of a mixed gas, consisting of Atmospheric air, Carburetted hydrogen, Hydro-sulphuric acid, Carbonic acid, the proportions of which vary at different times. The residue of the water very gently evaporated yields at times traces of phosphate of ammonia. Its boiling point is in glass = 213°°5 Fahr., barom. 30°2 inches. Its specific gravity is = 1:02770 at maximum found. 148. The water from No. 3, or clear sea water, at 115° Fahr., is of course, in all respects, the same as the water from Kingstown Harbour, except containing less combined air. 149. The water of No. 4, or that from the river Liffey, within the tidal limits, consists of a variable mixture of water, having the same constitution as that of Kingstown Harbour, with the water next to follow, or No. 5. It is alternately fresh and salt with the rise and fall of tide, and always foul; much organic matter is suspended in it, and some extremely divided silex. It evolves hydrosulphuric acid and common air on boiling, and contains about one volume of these in twenty of water. One cubic foot of it contains, after filtration, 581°5 grains of solid matter, which consisted of Putrified organic matter . . . . . . . 28°00 Chloride sodium ee eh ot. ohn 5 Meer nee Chloride and bromide of magnesium . . . 6°10 Sulphate [IME . <5 es ss ys ee ee Sulphate magnesia . . . . - + + « + 3°00 Loss ee ah er eee ernrre mre” tsk 28S 100°00 Traces of ammoniacal salts also are found, and of phosphoric acid or phosphates. Its specific gravity is = 1:00227, and its boiling point is in glass 212° Fahr., barom. = 30°1 inches. 150. The last water, No. 5, or that of the clear stream of the Liffey, above the tidal limits, and above the city of Dublin, — contains one volume in eleven of mixed gases, which are at- mospheric air and carbonic acid, generally in about the pro- — portion— ANE his. vaurtem fie taco uel PA scubie amelie Carkionic sacl. eo Sled ice Ve 1g 8 - 100 4 ON THE ACTION OF AIR AND WATER UPON IRON. 225 It is clear, free from smell, and when first taken up is tolerably well tasted, but soon becomes, in a close vessel, unfit for drink- ing. A cubic foot of it contains 299 grains of solid matter, consisting of piipiate Iyer HAG Sie Woe! UW) by: 52°53 Carbonate lime.-. . . . . , a0*, aga POMUOMMe TEN site 88 Chloride calcium . . . . Ee pi i 2 2 Chloride magnesium . . . . . . . 4:99 Chloride sodium . ... ., , mane: ee Beas Mert a3 Criteria ries ii) RSI 13 100°00 It gives uncertain traces of a free alkali, probably carbonate of soda, derived in all probability from the beds of albite, over which the river Liffey passes, a fact long previously noticed by my friend Dr. Apjohn. The boiling-point of this water-is 214° Fahr. in glass, barom. = 30°15 inches. Its specific gravity is = 1001-39; its saline contents vary very slightly between winter and summer. 151. All the waters in which the various classes of iron ex- perimented on have been immersed are now described ; and as the methods by which these experiments have been conducted, the particular objects in view and the precautions observed have been detailed in my previous report*, it will only be further ne- _ cessary to premise that— 152. The corrosive action of air and water in the above con- ditions upon iron presents its effects in five characteristic states of oxidation or rust, on the surface of the metal varying with the nature of the cast iron, the mode of casting, &c. &c. These are referred to in column 13 of the tables of results, the nomen- clature of which it may be necessary to explain. It is unchangeable in all the tables, and embraces the follow- ing terms, which are thus explained. Ist, Uniform, or when the whole surface of the iron is found covered uniformly with @ coat of rust requiring to be scraped off, and leaving a smooth ‘Ted surface after it 3 2nd, Uniform P., or uniform with plum- bago, where the surface, as before, uniformly corroded on Scraping is found in some places covered with plumbaginous Matter}, and leaving a “ piebald”’ surface of red and black after it; 3rd, Local, where the surface of the iron is found only rusted im some places, and free or nearly free from rust in others ; 4th, Local Pitted, where the surface is found as in the last * Report, § 68 to 84. ' $ Report, § 20. 1840. Q 226 REPORT—1840. case, but on scraping the rust off the metal is found unequally removed to a greater or less depth beneath it, so as to leave a pitted uneven surface ; 5th, Tubercular, where the whole of the rust which has taken place at every point of the specimen has been transferred to one or more particular points of its surface, and has there formed large projecting tubercles*, leaving the rest bare. In one or other, or some combination of these forms, every sort of iron, cast and wrought, which I have noticed, corrodes when exposed to the action of air and water, by which is meant water holding air in combination, such as all water at common temperatures found in nature does. 153. The 12th column in these tables contains the amount of water, if any, absorbed by the specimen of iron. It was con- ceived possible, from some known factst, that cast iron long under the pressure of water might from its porous crystalline grain absorb the fluid more or less like a sponge ; if so, it was necessary to know the amount of this as influencing the weigh- ings. Means were therefore taken to determine the point, and the tables show that in almost every case no absorption has occurred; where it has, the result is to be attributed without doubt to a minute “ blow-hole,”’ or cavity in the casting. It is certain, however, that under a sufficient pressure, cast iron may be caused to absorb water or other fluids, and experi- ments are in progress to determine the conditions of this ques- tion, which is not without interest and utility. The difficulty of obtaining cast iron impermeable to fluids is well known to the makers of hydraulic presses. 154. The tables Nos. VI., VII. and VIII. reduce into a small compass the whole of the results of the preceding ones; their own headings sufficiently explain their particular objects; it is therefore only necessary here to make some general obser- vations on a few of the more striking results arrived at so far. 155. On the average it will be seen that the metallic de- struction, or corrosion of cast iron, is a maximum in the clear sea water at the high temperature of 115° Fahr. (y), and that it is nearly as great in the foul sea water (8), while it is a mini- mum in the clear river water (¢). 156. The temperature is not higher in the first case than iron in works of engineering, or in iron ships is likely te be exposed to in different parts of the world, as the following data in- dicate :— * Report, § 49 to 59. + Report, § 37 to 58. ON THE ACTION OF AIR AND WATER UPON IRON. 207 A thermometer sheltered from radiation and on land does not rise, in any part of the Bloke above. bac ani oame) wie. ela) 400148 Fahr. One similarly situated on the open sea, no-where rises above . . +. . . . . + 87°8 Lowest observed temperature on land . . — 58° Temperature of the sea in any latitude or sea- son, never rises above. . . . . . « + 86° Nor has been observed lower than . . . — 29°* At the mouths of tropical tidal rivers, or in lagoons, the tempe- rature of the water, however, may reach a much higher limit. 157. I would here remark a cause of increased corrosive ac- tion, affecting castings, such as cast-iron piling, &c., at the mouths of tidal rivers, which has not, to my knowledge, struck previous observers. It is well known that the sea water, during the flowing of the tide, from its greater density, forces itself beneath the river water like a wedge, and slowly and imperfectly mixes with it, hence two strata, one of fresh or brackish water, the other of salt water belowit. Thus while engaged in a diving-bell survey of part of the bed of the river Bann, in the North of Ireland, last year, I found, during the flow of tide, the water strongly saline at the bottom of the river, and yet fresh enough to drink within three feet of the surface, the total depth of water being about 25 feet; and in the Proceedings of the Royal Society of Edin- burgh (April, 1817) will be found a paper by Mr. Stevenson, C.E., in which he describes analogous phenomena as occurring at the mouth of the river Dee, at Aberdeen, in the rivers Forth and Tay, and at Loch Eil, where the Caledonian Canal joins the Western Sea. On taking water up at various depths at Fort William, he found the specific gravity ‘ At the surface = 1008-2, At 9 fathoms = 1025°5, At 30 fathoms = 1027-2, or completely fresh at top, and salt as the sea itself beneath. ‘Now Becquerel has proved that a homogeneous metallic sur- face (a rod or wire for instance) exposed to the action of a fluid “menstruum, will assume a state of electrical tension, provided ‘that the fluid in which it is immersed be of different density in _ two strata, 7. e. of different corrosive power. In fact, the “metal and the two layers of fluid constitute a voltaic pile of one solid and two fiuid elements; hence as one end of the ‘metallic rod will be in a positive state with respect to the ‘other, it will be corroded faster than the other. Now this * Annales de Chimie, xxvii., 482. Q2 228 REPORT—1840. is precisely the condition of any casting reaching through a considerable depth of water at the mouth of a tidal river. The water is salter below than above, the part of the casting im- mersed therein (the lower end of a cast-iron pile for instance), will therefore be in an opposite electric condition to that of the portion above, and the amount of corrosion of the positive ele- ment due to the kind of iron, and the state of the water, will be further increased or ‘‘ exalted”’ by the negative condition of the opposite end, which will be itself in the same proportion pre- served. This principle extends to very many practical cases, as to iron plates, &c., partly immersed in a solvent fluid, and partly exposed to moist air, &c. ; and it suggests the importance of giving increased scantling to all castings intended to be so situated, to allow for this increased local destruction of material. 158. In section (138) of my previous report, I stated the fol- lowing as important desiderata for experimental answers as touching the subject, viz., I. The rate of progression of corrosion in sea and fresh water, with reference to increasing depth. II. The comparative amount of corrosion in the same water at various temperatures, within the limits of climate and season. III. The determination of the relation between the saltness of water and its corroding effects on iron. I am now enabled to state the law governing each of these conditions, as deduced experimentally. 159. And first, with regard to depth: if water held in solu- tion or combination the same volume of air or oxygen (not constitutional) at every depth, then the amount of corrosive action of the menstrua on iron or any other metal standing in its rela- tion to air and water, at any given depth, will be to the amount of corrosion of the same iron at any other depth, inversely as the depth. This supposes the water stagnant, and that fresh supplies of combined air are derived from the surface, and not from a lateral current. It also only applies to moderate depths ; and it is possible that at very great depths this law might not hold true. 160. We do not know with any certainty whether deep waters, or the ocean, contain the same proportions of combined air at all depths; but within twenty-four feet I have not been able to find any difference in the volume of combined air from that at the surface in either sea or river water. 161. This determination, of course, will not apply where a constant supply of water, holding new quantities of combined air, is brought in laterally, as in a tide-way or river. In this case, ON THE ACTION OF AIR AND WATER UPON IRON. 229 if the proportion of combined air be the same at all depths, it seems probable the corrosion will slightly increase with the depth ; but the matter is now under experiment. 162. The second question, namely, at what temperature the corrosive action of water on iron is a maximum, has with each (sea and fresh water) two conditions, namely, when the water is combined with air, and when it is freed from it by boiling, or otherwise. 163. In the first case, namely, in water and combined air, I find corrosion proceeds fastest in fresh water at temperatures varying between 175° and 190° Fahr. 164. I find, further, that the rapidity of corrosion is in the direct ratio of the volume of combined air at any given tempera- ture; and lastly, I have found, on slowly heating water holding air in combination from 60° Fahr. up to 212° Fahr., that the air is evolved most freely, and in greatest volume, at 190° to 195° Fahr.; hence we at once perceive that the reason why the maximum corrosion of fresh water with combined air is between 175° Fahr., and 190° Fahr., arises from this being the point at which the attraction of the water for the air is destroyed, or nearly so, and hence the latter left free to combine with the metal. 165. If fresh water be deprived of all combined air, its cor- rosive action on iron ceases tm foto in a close vessel; nor does corrosion commence at a boiling temperature ; but if the vessel be open and very shallow, the heat even of ebullition does not prevent the absorption of air; and oxidation, once commenced, goes on even more rapidly than at a lower temperature. 166. Information is yet wanting as to the temperature of maximum corrosion of sea water, a question of greater intricacy and importance with reference to marine boilers, and now in course of experiment. 167. As regards the third question, namely, the relation be- tween the degree of saltness of sea water and its corrosive power for iron at common temperatures, I find that in sea water, de- prived of combined air, acting on iron in an open vessel, and having therefore to originate its corrosion by air drawn from the atmosphere, the corrosive power is inversely as the density of the solution, or the amount of its saline contents. __ 168. And in the case of sea water holding air in combination, the corrosive power is compounded of the direct ratio of the volume of combined air, and of some function of the amount of saline contents. 169. The tendency of dissolved salts to prevent the absorp- tion of air by water, which is such, that a saturated solution of 230 REPORT—1840. sea salt, deprived of air, can scarcely be made to absorb air at all; and that in dissolving most salts, expel the combined air from the water of the solution, united with the circumstance, that the voltaic conducting power of the water is greater in proportion to the amount of its saline contents, indicate that fresh water may hold so much combined air (not to speak of carbonic acid) as to act more rapidly on iron than sea water; that, on the other hand, with much less combined air, the superior conducting power of the saline solution may place its corrosive power on a level with or above that of the former; and that, by the variable combination of these two elements, within their respective limits of saturation, any assignable ratio may exist of the corrosive power of aérated fresh and sea water. This might seem to render our enlarged experiments in the open sea nugatory; but it will be recollected, that the compo- sition of sea water, both as to solid and gasiform contents, is very nearly constant. : The experiments from which these conclusions* have been deduced, were made on equal parallelopipeds of the cast iron, as in class No. 1. « 77, exposed during equal times, and the oxides produced washed off, filtered and weighed; hence they were all made in vessels of limited size. The part which the combined air plays in these reactions is very remarkable ; it seems to belong to the same class of phe- nomena as those known both in inorganic and organic chemistry, where the presence of a third body is required to commence or sustain the reactions of the three, any two of which alone are quiescent. Thus gallic acid, lignin and other analogous sub- stances, suffer no change, either in air or in water; but add to the water a minute portion of an alkali, or alkaline earth, and the process of oxidation commences at once. Alcohol stands in the like predicament. 170. It seems probable that the air, in the case of the reaction on iron, is not decomposed directly by the iron at all, but by its protoxide, previously formed by decomposition of the water, catalytically, or due to the presence of the combined air. If so, we should expect to find hydrogen evolved from the first mo- ment, as well as nitrogen, produced by the decomposition of the air. But water, although combined with air, absorbs about one and a half per cent. of hydrogen, while, unless the air be previously expelled, it absorbs no nitrogen ; hence decomposition proceeds for some time before hydrogen is evolved; but on stop- ping the reaction at an early stage, and expelling the air and * Report, § 158 to 169. ON THE ACTION OF AIR AND WATER UPON IRON. 231 absorbed gas, traces of hydrogen can be detected: at a subsequent stage, and especially if the mass and surface of iron be great in proportion to the volume of water, hydrogen and nitrogen are both evolved, and the white, greenish or black oxides before produced, become red. When this has arrived, the presence of air is no longer essential to carry on the decomposition of the water, the sesquioxide of iron, which acts as an acid to its own base, supplying its place. At a still later stage, ammonia is very frequently formed, especially where much carbon is disengaged from the iron in the state of plumbago. These reactions closely analogize with those presented by tin when acted on by nitric acid. This metal, when pure, will scarcely, if at all, decompose water cold; yet, when it decomposes nitric acid, it decomposes water at the same moment; hydrogen is given off, and ammonia is sometimes produced during the oxidation of the tin; but this rather digresses from the practical intention of the present re- ort. 171. The powerful corrosive action of foul sea water (evi- denced in Table No. IV.) by water holding putrifying organic matter in solution and suspension, is due, in great part, to the quantity of hydrosulphuric acid (H+S) disengaged from the mud at the bottom, and with which the water is im- pregnated. The iron, acted on by the water in presence of its combined air and carbonic acid, forms hydrated oxides (Fe O+H O) and (Fe, O,+Fe O+H O), and carbonate of iron (Fe O+C O,), and probably, in some cases, basic salts of some organic acids. These, continually exposed to streams of hydrosulphurice acid, are in part converted into protosul- phuret of iron (Fe §), and in part into the bisulphuret of the protosulphuret or magnetic pyrites (6 Fe S+ Fe S,), both being _ formed in an amorphous state, or occasionally deposited in mi- ~ croscopic crystals in the tissue of decaying organic substances. Both of these sulphurets are of most unstable constitution, and rapidly oxidize under the action of air and water, forming proto- - sulphate (Fe O+S O;) +6 HO, and the disulphate of the sesqui- oxide (2 Fe,O,+SO;) +6 H O, and frequently various other more _ basic sulphates. These, when soluble, are washed away, and _Yapidly expose fresh surfaces of the iron to oxidation. In every ase, the water charged with these salts has become a better conductor, and amore powerful agent in maintaining corrosion. _ But organic matter in a state of putrefaction is one of the most powerful deoxidizing agents known,-—so much ‘so, as to be capable even of reducing sulphate of lime in the state of gypsum ; hence these sulphates of iron are in their turn reduced in part 232 REPORT—1840., back to sulphurets ; and accordingly, in the neighbourhood of iron exposed in these conditions, organic matters are frequently found, lined, penetrated, or coated with crystals of bisulphuret of iron (Fe 8), or common pyrites, while their oxygen has gone to form carbonic acid and hydrosulphuric acid, both in their turn again to react in presence of air and water upon the iron. Hence, then, the prodigious power of degradation of castings or forgings of iron, when exposed to the foul water of the sewer- age of great cities, as so often observed; hence the cause of the destructive action of ‘‘bilge-water’’ upon the holding down bolts of marine engines. 172. A very interesting case, verifying the occurrence of these phzenomena, has recently been observed and examined by the ac- curate Berthier*. ‘On the 15th June, 1837, an ancient malle- able iron anchor was taken up from the bottom of the river Seine, nearly opposite Gros Cailloux. It was found imbedded in a conglomerate of pebbles, bones and altered wood, with grains of sand and fragments of pottery, of a light gray colour, and held together by a calcareous cement, which had accreted round the metal. The anchor was two metres long, and weighed not less than 200 kilograms. It was thought to be of the fifteenth century ; its form, however, agrees with those of the sixteenth; and it cannot be more ancient than a.p. 1400. ‘The crust was easily detached by a blow. At one end was found a piece of wood in immediate contact with the iron; this had pre- served its ligneous texture, so as to be easily recognisable ; but it was deeply altered in its qualities. Its aspect was that of a dark gray homogeneous mass, with an uneven fracture, and it was strongly magnetic. By calcination and roasting, it lost 0°375 of its weight, and exhaled a strong odour of sulphurous acid. Acetic acid dissolved from it 0°65 of pure carbonate of lime, while hydrochloric acid dissolved it nearly entirely with disengagement of hydrosulphuric acid. «The residue was composed of portions of unaltered wood, mixed with a small quantity of persulphuret of iron (bisul- phuret). “‘The analysis of the whole gave Carbonate lime . . che hake Tova FeS=protosulphuret iron. . . . 0°18 FeS,=persulphuret'iron . . . . O07 Ligneous patter Ae Yo OE Mt 0) et ee 1°00 * Annales des Mines, vol. xiii. p. 664. ON THE ACTION OF AIR AND WATER UPON IRON. 233 The iron must be, for the greater part, in the state of mag- netic pyrites (6 FeS+Fe S,), and the remainder in the state of persulphuret. The gray paste of the crust is coloured like- wise by the sulphuret of iron [Berthier does not say which]. *«The production of sulphuret of iron at the surface of this anchor in the Seine in contact with wood, is not surprising, since we know that its waters contain sulphate of lime, and that sulphates in solution are converted slowly into sulphurets in presence of organic matter, with production of carbonate of lime. “The carbonic acid, dissolved in the water, must have had likewise some influence on the results of this reduction, and it is probably to its presence that we may attribute the forma- tion of the persulphuret of iron.” These facts sufficiently indicate the accordance to nature of the theory of reaction of putrid waters which has been advanced, and are fertile in conclusions of practical importance to the en- gineer occupied in works of construction in iron, connected with the docks or harbours of large towns, or in similar situations. 173. The average minimum corrosion is indicated (by Tables V. and VI.) as occurring in clear river water, containing air in combination. This difference below the index of corrosion for clear sea water is to be accounted for upon the general princi- ples already laid down*; and as subsidiary causes influencing the results are to be noticed, the absence of all extraneous cor- rosive agents, and the circumstance that the coat of oxide of iron formed in fresh water adheres obstinately to the iron, often forming imperfect crystals, of brown hematite (fer oligiste), and is not removed in a loose pulverulent form with the same €ase as it is in sea water, and hence acts in some degree as a cloak, or partially impervious covering, to defend portions of the metal from further action. - 174. It will be further observed, from Tables III. and VI., that wrought iron suffers greater loss by corrosion in hot sea “water (temp. 115° Fahr.) than under any other circumstances— an important result as respects the construction of marine en- gines and boilers. Upon the latter point a special set of ex- periments are in progress, having in view principally the points of inquiry suggested +; and should the results of these experi- ments give a decidedly advantageous point of concentration at which to work marine boilers (other circumstances being consi- | dered), there will be no difficulty, by the aid of the brine-pumps now occasionally used in first class steamers, and of Mr. Sea- * §§ 167, 168, 169. + First Report, § 78. 934 REPORT—1840. ward’s salt gauge, in preserving any such saline condition in the water within the boilers as may be desirable. 175. These Tables also show that in general the removal of the exterior “‘skin”’ of a casting by planing or filing, to the depth of one fourth of an inch or more, greatly increases the corrosive action of air and water upon it, so that the cast irons so cir- cumstanced show an average amount of corrosion, or, as I have ventured to name it in the Tables, have an index of corrosion not much less than that of wrought iron. This shows promi- nently the value of a close-grained and dense metallic surface for durability. 176. We further remark, that while wrought iron corrodes faster than cast iron, with the skin so removed, in clear sea water, on the contrary, the cast iron, with its surface or skin removed, corrodes faster than wrought iron in clear river water. This is due to the circumstance that the coat of hardened oxide (fer oligiste*) formed in clear river water, adheres much less obstinately to cast than to wrought iron, and hence me- chanically protects the former less, while in sea water the coat of oxide formed is more or less pulverulent in both cases. 177. There are two facts of an altogether novel and singular character which these Tables present us with for the first time —the first, that “‘ chilled ’” cast iron, of whatever sort, upon the whole corrodes faster than the same sort of iron cast in green sand; the second, that the size, or scantling (and perhaps the form) of a casting in iron forms one element in the rate of its corrosion in water. 178. With respect to the first, I have remarked}, that chilled cast iron is that which, as compared with mottled or dark gray cast irons, should corrode with the least rapidity on principles considered as established. The facts now for the first time elicited by experiment, however, show the di- rect contrary to be the case. This may appear at first sight to conflict with the principles already laid down ; it does not, however, do so in any respect. It is still quite true that chilled cast iron (that is to say, cast iron containing a minimum of sus- pended or uncombined carbon, and of the highest density) will corrode the most slowly, provided it he homogeneous tf. But practically, the exterior surface of no chilled casting és homogeneous; on the contrary, it is variable to a greater degree than that of any other sort of casting, hence the forma- tion of those innumerahle voltaic couples by whose action cor- rosion is promoted: in other words, the results of the present * § 173. + See §§ 39, 44, 49. t § 55. ae ~~ —______— ON THE ACTION OF AIR AND WATER UPON IRON. 235 experiments show that the voltaic action produced at the sur- face of chilled cast iron, by its want of homogeneity, increases the corrosion of the metal by menstrua, to a greater extent than its great density and hardness, and small amount of uncombined carbon, are capable of retarding its corrosion, in comparison with other sorts of cast iron. In confirmation of this it will be observed, that in almost every case the condition of the corroded surface of the “ chilled’ specimens has been “ tubercular,’”’—a form of rust which, whenever it is found on iron, is an unfailing index of a want of uniformity of substance. This want of ho- mogeneity, however, is less in every chilled casting as we recede from its surface towards the interior; and, accordingly, I ex- pect that the result of the next two years’ corrosion of those specimens, the whole of which are now immersed, and proposed to remain so for that period, will show rather a diminished excess in the index of corrosion of ‘ chilled’’ over the other sorts of cast iron; the difference also diminishes with increase in bulk of a chilled casting, which must be more uniform the larger it is. 179. This leads to the second fact brought to light by these results, viz. that the size (and perhaps the form) of castings in iron influences their rate of corrosion. With the view to deter- mine whether any difference in this respect might exist, it will be seen that in the series «, immersed in clear sea water, nearly every sort of cast iron has duplicate specimens experimented on; viz. of one inch in thickness by five inches square, and of one quarter of an inch in thickness by five inches square, but differing in no other respect whatever save in this one dimension only. Yet it will be observed, that throughout the amount of corrosion of the quarter of an inch, or thinner pieces, is greatly more than that of the thicker, or one-inch pieces of each sort of iron. The difference is greatest in the softest and most carbonace- ous, or rather “graphitic”? cast irons, and least in the hard, dense, silvery cast irons. Thusin the Vartey Hill (No. 2) hot blast iron, the index of corrosion of the quarter-inch casting to that of the one-inch, is about 5°5 : 1; in the Cinderford (No. 1) cold blasts as 10°35; in the Muirkirk (No. 2) cold blast as 11°5 : 3, while in the Calder (No. 4) hot blast it is only as 6°76 : 6°20, or nearly in ratio of equality. This very striking circumstance would scarcely have been predicted before the present results forced it on our notice; yet its rationale is easy upon principles just applied to the case of “chilled’’ castings. These thinner castings have cooled much faster, and more irregularly than the thicker, or one-inch 236 REPORT—1840. ones ; hence are much less homogeneous, and contain dispersed veins and patches harder than the rest of their substance ; hence again the formation of voltaic couples, and accelerated corro- sion of surface. 180. This novel fact leads us to some important practical deductions. We at once see the advantage in durability that weight for weight castings of massive scantling have over those of attenuated ribs and ‘“‘feathers.’’ We see the importance of casting the ‘‘feathers’’ on ribbed castings intended to be sub- merged, of equal scantling with the other parts to which they are attached, otherwise the attenuated rib will be eaten away long before the principal parts of the casting will have suffered much ; and this not merely because there is less stuff in the rib to be eaten away, but because its smaller size gave cause for its being eaten away proportionally faster, and in preference to the grosser rib. 181. We see the importance of having all ribbed castings cooled in the sand before being stripped from the moulds, so as to ensure the greatest possible uniformity of texture if intended to be submerged. Indeed, this precaution ought to form part of the engineer’s specification for guidance of the founder in preparing castings for every aquatic work, and for other reasons it might be added for every work. 182. These views give the rationale of the fact which has been often noticed, but never explained, that the back ribs, of cast iron sheet piling, decay much faster than the faces of the piles, al- though the latter are more exposed. Thus in the Blackwall piling the front ribs of the main piles are two and a half inches thick, while the “ feather’ or back ribs are but one and a quar- ter of an inch; in the sheet piles the front ribs are one and a half or one and a quarter inch, and the feathers but one inch. 183. The principles we have now got also indicate that cast- ings in “ dry sand and loam,” will probably be, ceteris parthus, more durable under water than those cast in “ green sand.”’ 184. In general, the results of these experiments show that the cast irons with low commercial marks, the numbers 3 and 4, &c., corrode locally and generally become pitted ; while the high marks, the numbers 1 and 2, &c., corrode with considerable uniformity over their whole exposed surface, in accordance with the general principle just stated. 185. On the whole, the practical preference appears so far to be due to the Welsh cast iron for aquatic purposes ; a fortunate circumstance, seeing from thence we draw the largest supplies of iron. Closeness of grain is especially desirable, and what- ever can be done in way of mixture of different makes of iron ON THE ACTION OF AIR AND WATER UPON IRON. 237 to increase this property will be valuable. Still more definite results, however, are to be expected from the examination of the suite of specimens again after their present immersion. 186. With respect to cast irons made by the hot and cold blasts, the index of corrosion appears to be, on the whole, slightly in favour of the cold blast, but not much; a circum- stance possibly attributable to the hot blast iron containing a different proportion of alloyed metals of the earths and of sili- con, as Dr. Thompson has shown*, and to their general differ- ence in density, as hereafter to be noticed. 187. The great elements of difference in corrosion, however, as respects the iron itself, appear to be,—I. The degree of ho- mogeneity of substance of the metal, and especially of its sur- face. IJ. The degree of density of the metal, and state of its crystalline arrangement. III. The amount of uncombined carbon or suspended graphite contained in the iron. The more homogeneous, the denser, harder and closer-grained, and the less graphitic, the smaller is the index of corrosion of any given specimen of cast iron. 188. The Table No. VIII. is one deduced from all the pre- ceding, in which, assuming the rate of corrosion found by ex- periment for a period of 387 days, to continue uniform, the ave- rage loss per superficial foot of surface, for each general class of iron, and thence the depth to which any casting will he cor- roded in a period of one century is shown. This may be con- sidered as a specimen table, showing one practical end pro- -posed by these results. _ 189. The assumption here made, that the rate of corrosion will continue for a century uniformly as during the first year, is possibly not critically correct ; the error, if any, however, is one not in excess, but in defect, for though the rate of corrosion may accelerate, it certainly is not likely to be retarded. This point the results of the continued experiments on the same specimen now in progress will, after two years more, fully determine. Meanwhile I have strong reason to conclude that, after a suf- ficient period has elapsed to enable submerged cast iron to be- come coated with a spongy covering of plumbago produced by its own destruction, then the further rate of corrosion will be somewhat accelerated, and that hence the results contained in this table are rather below the truth. 190. These deductions, in general, indicate that from three to four tenths of an inch in depth of cast iron, one inch thick, and about six tenths of an inch in depth of wrought iron will be destroyed in a century in clear sea water, a conclusion probably * Report of the British Association, vol. vi. 238 REPORT—1840. not very far astray where no special perturbations or causes of corrosion supervene. 191. This gives a period of duration of about two hundred years to the cast iron wharf wall, lately constructed at Black- wall, London, before the castings shall have become so atte- nuated and fragile as to be useless. 192. Having been recently in correspondence with Col. Pas- ley, Royal Engineers, and Lieut. Symonds, of the same corps, regarding the state of the iron taken up from the wreck of the Royal George, with specimens of which I have been favoured by the former gentlemen, an opportunity has occurred, through in- formation for which I am indebted to Lieut. Symonds, of controll- ing or testing the accuracy of these results in a very decisive way. A number of guns have been taken up from the wreck of the Edgar, which were upwards of one hundred and twenty-nine years under water. The depth to which they were corroded from their original dimensions, which were known, was found to be seven-eighths of an inch on the average. Now let us ap- ply the results of our experiments to see what depth of cor- rosion they predict under the circumstances. Turning to Table No. VI., we find the average loss for hard gray iron with the skin removed (as in a bored gun) per square inch of surface in 387 days = 13°55 grains in foul sea water = 1951°2 grains per square foot, which, multiplied by 123°4, the times 387 days is contained in 130 years, and divided by 7000 = the grains ina pound avoirdupois, give a loss by corrosion of 344 |b. per square foot; but the actual loss has been 32°81 Ibs. per square foot, that being the weight of a square foot of cast iron seven eighths of an inch thick. This strikingly close result is corroborated by others on iron from the Royal George, immersed for fifty- eight years, corroded from half an inch to three fourths of an inch in depth on the average, and together prove that the re- sults of these experiments may be relied on practically. 193. I have now to make a few remarks upon the supple- mentary tables which accompany the five first tables of experi- ments, viz. those containing the results of corrosion of cast iron covered with various paints and varnishes. These were mostly such as are generally in use for such purposes, and were laid on with great care, so as to cover the whole surface completely, and leave as few microscopic pores as possible in the covering. The general results are these : of the ten sorts of paints or varnishes tried, there is not one that will completely prevent corrosion,- nor one that will remain perfectly adherent or undecom- posed for a single year under water. In foul water, fresh or ON THE ACTION OF AIR AND WATER UPON IRON, 239 salt, white-lead paint perishes at once, the white-lead being probably converted into sulphuret by the action of the nascent hydro-sulphuric acid ; yet white lead forms the great staple base for all the paints generally used for exposed iron works. Caoutchouc varnish appears to be the best covering in hot water, and generally in all the others asphaltum varnish. But boiled coal tar laid on, the iron being hot, has decided advantages over every other, the reasons of which we shall presently see. It is sufficiently obvious, however, that nothing very important in the way of protection is to be hoped for from any one of the coverings tried, at least when used alone. 194. Since these experiments were commenced, my atten- tion has been drawn to the results of an analogous series obtained by Mr. James Princep of Calcutta, and contained in the Journal of the Asiatic Society of Bengal, which appear worthy of notice. The proposed extensive employment of iron steam-boats on the Ganges, and the rapid corrosion to which iron is subject in a hot climate, induced the local government to cause these expe- riments to be made, to endeavour to procure a varnish that should preserve the surface of the metal. Mr. Prinsep took two sets of six wrought iron plates, each 3 feet by 2 feet, upon which various paints and varnishes were applied. One set was just completely submerged, and the other half-immersed, one half of each plate being in the air and the other half in the water of the canal at Calcutta, near the Chitpur lock-gates, where it is only slightly salt. After three months’ exposure the two sets were taken up and examined, and the following table contains the re- sults, which it is to be regretted have not the numerical pre- cision that would have been obtained by weighing the plates before and after immersion. Experiments 1840. REPORT 240 *paanfar apayty axomasya ‘padesos udaq prey 31 a194M 10 ‘saspa oy} uo Aysny *paulios Dey ySNAD JO 310s B ALI 41078 dopun uvgy ie ay ur Ajsna o10m YONA [jam Ayjaad sow pue ‘uo sureued we UT “197M Japun [[e sVaojeid si, *paposios yonut A190 A. ‘ara MAIVAD NO Sut -yeorq ysna Jo sjods { pauojztym sso] 1B UT *poaoutar Apa11y “ua 19jeM MOTIq 3Nq £ padAsosaid aje\d pue ‘y1vu-1ajem aAoqv poainfurun yuieg ‘JayVM BAOGL poasosaad ay2yd fury) asaya youtq fyo149 d1IYM pauozyAr funs ay} 0} pasodxa yard ayy JO UONDV.YUOD Jy} WO’y syovsD adIVT *19}UM DIP) JO [AAI] 9} IV YSN Jo out] W "AVA BY} JO [AAI] AY} 3v YSN JO s}op May VW *19]EM urj|ey pur ie ut Jey sazejd uo ‘syyuou ¢g ur 4[Nsax *paasasord yjam Aye1d pur ‘pauaiiyA api] @ SBM DOVJANS [vANjeU at, *poyBpIxO Os[e dUIZ ay} £ peq pue papossod AjaAisnjoxa uot uva]o aly, *papos109 yonur f19A pure ‘yo payaad ‘Axe LT *Aqysna A19A pue Yjoy XBM jo 990.13 0 [oda p ll 3 N “sysna Aron pu ‘pauazry *payepixo yonut jou nq ‘jjos pue “uajnseatnd ‘pauoziy AA ‘adRJANS OY} UO ISNK Jo sayojo[q pur ‘paavoddesip Ajjoym ysouy *a19} pue ajay ysnx 4am aTIYA YO paqqna Ajisva pue yjos {4yuaepnsaajnd pue aziy AA ‘aouvavadde ur poanfurun Apoaji0g *S[[O4 Ot} WIOIZ auivo 41 sv ‘aprxo fviS yensn oy} YM paiaaod put ‘payonojun ajzeid uosr ayy, | “OT *pauvayo uoym oye[d a3 punox parapjos paend 10 Suispa uv ‘ ourz *19JVM-IUATT 9ANd Jo YseAr a31t] AA ‘adBJANS OY} UO pasjauI f XVM aTIY AA *pauriem ‘sjyvod [etaaas £ ystuava yauidg *k{pidex parap ‘sjwoo g £ ystusva [edog *A[Avou ‘syjuour g 10 uspaey pus Arp 0} pamoye fs}eoo g fyured peal-aiiyM Iso ‘yeoo UDADUN YIY} B Ul YOY UOIT ay 0} pordde § ystuava oaneu eB ‘vungd “4209 dUO ‘QA0}S @ UL Udy} puv ‘WOOK [00d Ul SAY *4snd WoOJJ aa1y puv ‘paasasaid Apoajiog *pasromqns Ajo saqeid uo ‘syyuoUr ¢ Ur 4[NS2zZ ‘1p 07 syJUOU OMY : BAY JO YsiUAvAs dasJoUL J, *poywoy aed £ 30Y uo prey ‘1e} [BoD *poyjdde Moy puv ‘duriaA0d Jo 410g ‘sasuDy ayz ur apou ‘uouy wodn saysiuiny pun szuM_ UO spuaurwadu ON THE ACTION OF AIR AND WATER UPON IRON. 94] Coal-tar thus appears to stand preeminent as a covering varnish for iron. The general accordance of these experiments with those of the present report is satisfactory. The anomalous re- sult, No. IX., with the zinc protector, Mr. Prinsep considers due to its containing lead, which was proved to exist in it. Coal- tar was finally adopted for the iron vessels navigating the wa- ters of the Ganges. 195. In the progress of these researches I procured, by the favour of Henry English, Esq., of the Mining Journal, a speci- men of “ zinc-paint’? now sold asa covering for iron when ground in oil; that which I received is in the form of a mode- rately dark, gray powder, which decomposes water rapidly ; suf- ficiently fine to form a strong full-bodied paint, when ground with oil, which dries rapidly, though not quite free from gritti- ness. As I could not obtain any very definite information as to the origin or mode of preparation of this substance, and its va- luable qualities were highly spoken of, I considered it worth making a quantitative analysis of. It will be unnecessary here to state the method pursued; the analysis was performed with care, and the results give the following composition as that of the zinc-paint : Sulphuret lead Sf ethene S905 Sub-oxide and oxide of zine . . 4°15 Mictallio Zine 2.5627 acess. ood 81°71 Sesquioxide iron whe Rite ae Pale Mel ib. un Sh, Pali ig ADEE SEN Rl") be0s' sale 88 chs BO Bose. eek tie (iy hus. Wigiodeo4 100 It would hence appear to be probably some residual matter obtained in the zinc-works. Ihave at present specimens of it upon iron in all the six conditions of experiment, and hope at a future period to be able to report favourably of the results. I should, @ priori, conceive that it would make an excellent body for a sound durable paint, well suited to works in iron. 196. Another sort of paint has been for some time much recommended by the vendors, made from impure black oxide manganese ground in oil. This may possibly form a powerful “drier,”’ but, from its harsh and dense substance, can never be a suitable “ body” for a paint; nor does it seem to offer any special advantage in the former respect. 197. The defects of ordinary oil-paints seem chiefly to arise from the instability of constitution of the fat oils, turpentine or other organic substances entering into their composition. 1840. R 242 REPORT—1840. All the fixed oils may, in fact, be viewed as organic salts or com- binations of the oily acids, with a compound base generally ** glycerine”’ (C,, H,, O,,), or vegetable mucilage. Most of the oil of turpentine found in commerce also contains more or less pinic and silvic acids*. Now all these acids readily quit their weakly positive organic bases, to form salts with the more powerfully basic oxides of the metals, with which they are used commonly in the formation of paints, as white lead, ochres, &c. &c.; in this combination, however, the original organic bases are left free to form new combinations, under the joint action of air and moisture, and of the metal on which they may be spread. The resultant action of all which is, that the paint, in workmen’s language, gets ‘killed’; that is, be- comes either more or less soluble in water, or pulverulent and removable by it; and in place of preserving an oxidable metal, promotes its corrosion. Pinic and silvic acids act powerfully as such, upon many bases; the former decomposes the car- bonate, acetate, and most of the organic acid salts of copper, several of the earthy acetates, and the alkaline carbonates with effervescence when fused with them. Yet it is remarkable, that upon the peroxide of copper, and several other peroxides, it has scarcely any action. The electro-negative relations of commercial turpentine, then, may be neutralized, if desirable, in composing a paint; but this is in every case attended with a diminution of its power to resist the action of water. Priestley first ascertained that volatile oils, such as turpentine, absorb oxygen or atmospheric air, and combine with them in part. In this they closely resemble the fat oils, and the result is analogous in both; they finish by conversion into resins. Hatchett’s experiments, and also the saponification by potass of oil of turpentine, indicate that the volatile oils do not unite directly with nietallic oxides, but receive oxygen from them, become acid resins, and thus form resinous salts. Thus, if oil of turpentine be heated with peroxide of lead, water is given off. The oil becomes dark brown, viscid, and at length solid ; the result is a compound of resin and oxide of lead; common resin, as Blanchet and Sellt have shown, is oil of turpentine, with an atom of oxygen combined = C,, H, O. Hence we may conclude that oil of turpentine plays no chemical part in the constitution of paints, but in so far as it has suffered these changes; in doing so its density is increased and its volume consequently diminished, and hence every oil-paint is full of microscopic pores, however carefully: laid on, as may be proved * Unverdorben, Poggendorff’s Annalen, vii. to xxi. Tt Poggendorff’s Annalen, xxix, 133. ON THE ACTION OF AIR AND WATER UPON IRON. 243 by the microscope ; and thus, when laid on an oxidable metal, corrosion slowly takes place through these, or, as workmen say, “it rusts under the paint.” 198. In the absorption of oxygen, which takes place when an oil capable of being rendered drying, such as linseed or nut oil, is exposed to the action of the atmosphere or of oxygen gas, the volume of carbonic acid formed is by no means equi- valent to that of the oxygen absorbed. Hence it is obvious that the drying of oily paints is effected by a slow but real combustion of part of the hydrogen of the oil forming water, and by the partial acidification of the vegetable mucilage. This process is greatly accelerated by the presence of various sub- stances, but particularly carbon in a solid state. It is well known that lamp-black and oils mixed together in proper pro- portions absorb oxygen so fast as to produce spontaneous com- bustion at high temperatures, yet it is the slow combustion of the hydrogen of the oil rendered more active by presence of the carbon, to which the exaltation of temperature sufficient to produce ignition was at first due. This combustion is already in part performed in the oils rendered drying by litharge, &c., and still more in the burnt oil used for the ink of copper-plate and letter-press printers, and called by them “the varnish.”’ In fine, in every combustible compound of carbon and hydro- gen, combustion, whether slow or defectively supplied with oxygen, seizes on the hydrogen first, and lastly on the car- bon, and this leads, in the case of oil paints, to a succession of changes of constitution, by which at length the original solid material of the paint alone remains in feeble combination with a little decomposing resin. 199. The direction, then, in which we are able to look for _ improvement in the preservative power and durability of our _ paints, is in choosing from amongst the known groups of _ organic substances, those which have greater stability than the fat or fixed oils, and which, in place of being acid or _ haloid, are basic or neutral. Amorigst the many substances of _ this class which occur, few seem better fitted to form a sub- _ Stitute for the fat oils in paints than the heavy oily matter obtained by the distillation of resin, to which M. Fremy gave the name of ‘ resinein*’; it has the composition (C,, H,, O). Now two atoms of resin = 2 (C,, H, O); hence this oil is a fluid resin deprived of an atom of water =(H O). It isa heavy transparent oil, destitute of taste or smell, insoluble in Water and alcohol, not acted on by caustic alkalies, has a high boiling-point = 480° Fahr., and reduces litharge, when boiled * Annales du Pharm. xv. 282. R 2 244 REPORT—1840. with it, as the drying oils do. This substance can be obtained in any quantity cheaply ; all the resins possess the property of gradually combining with water when long immersed in it, and forming a porous compound, analogous in all respects to the substance thrown down by water from a solution of resin in alcohol, or from its combination with an alkaline solution. When the latter is precipitated by an acid a true hydrate is formed, consisting of an atom of resin and eight atoms of water. Even copal, after having dried as a varnish, is gradually acted on in this way by water, and becomes pulverulent. Re- sinein, however, does not seem to be capable of forming a hydrate, and therefore offers decided advantages as an aquatic paint. 200. Reichenbach has lately shown* that Eupion (Cg; Ha) may be obtained by distillation of rapeseed oil. Naphthaline and Paraffine are both soluble in the latter; and these, from their stability of constitution and other properties, only require a suitable solvent to form the most valuable bases for paint. Naphthaline can be obtained in large quantity, in fact it is a drug with those who distil naphtha from coal-tar 5 and Laurent has shown+ that Paraffine may be obtained in abundance by distillation from the shale of the coal formations. In the com- bination of these with solid materials, the principal object to be held in view to obtain a durable paint is to choose a metallic powder or peroxide least liable to be acted on by the agents most obnoxious to paints, viz. air, water, carbonic acid, and hydrosulphuric acid, and at the same time capable of intimate combination with the organic base. 201. But ina paint, or rather varnish of Naphthaline or Paraf- fine, no solid inorganic substance is necessarily included. The only other component needed is a suitable vehicle to cause these substances to spread and hold them upon the metallic surface. This obtained, a varnish covering, more durable than any known, would probably be produced. This is rendered almost certain by the facts already adduced by Mr. Prinsep’s and my own ex- periments. In these, coal-tar laid on the iron hot is immea- surably superior to every other covering. Now coal-tar in this state consists of naphthaline enveloped in asphaltum ; when coal- tar is exposed to this temperature, naphtha and other volatile matters are driven off, and the results of an imperfect destructive distillation, in which hydrogen is lost, while naphtbaline is a product, remain on the iron a bright and solid varnish. This not only gives the key to the only true method of applying bituminous matter as a varnish, but it indicates the cause of the * Jour. fur Pract. Chim. i. 377. + Annales de Chimie, lv. 218. ON THE ACTION OF AIR AND WATER UPON IRON. 245 entire difference in preservative power observed between coal- tar so used and Swedish tar laid on cold; had the latter been heated also until decomposition commenced and naphthaline was formed, less difference probably would have been found between them. 202. In connexion with this may properly be mentioned the method stated to be used for giving the beautiful jet black var- nish coating to the Silesian or Berlin castings in iron. These beautiful specimens of art are covered externally with an ex- cessively thin coat of a black, shining, and remarkably hard varnish, which is not acted on for a considerable time by strong sulphuric or nitric acid, or for some hours by caustic potass, and which resists oxidaticn of the metal beneath for a long time; but, when continually exposed to air and water, at length forms isolated patches of rust, which gradually spread. The varnish is said to be thus produced :—the article of iron is sus- pended from a wire and covered with a very thin coat of linseed vil, it is then hung over a smoky wood fire within about a foot of the faggots, and exposed for some time to the smoke and flame—generally about thirty minutes ; it is then to be lowered to within three or four inches of the fire, now become clear, and heated more strongly for a few minutes, and immediately immersed in oil of turpentine, from which it is removed to be polished with woollen cloths. A second application is some- times requisite to give sufficient blackness and brilliancy, which is always more readily obtained with cast than with wrought iron. It is difficult to discern the precise nature of the changes which the oil undergoes in the process: watery vapour, Kupion and carburetted hydrogen are probably given off, and some of the volatile products of the wood, in imperfect combustion, may enter into combination. A different composition is recom- mended in the Dictionnaire Technologique, vol. xxii. p. 164, for producing this black varnish, viz.— Pntnentof Andra Leneihiais eT 2) sah. Fir Resins rot, pg te RPL Bea tts rai ih: lo lreely era ames es POTD BO Copal or Amber varnish . . . . . . 10 with enough of oil of turpentine to make it spread, laid on the iron hot and baked. 203. Amongst the mechanical coverings of iron for prevent- ing oxidation, may here be properly noticed the fusible enamel patented by Mariott, of London, and since by others. These are very fusible glasses, having, by the addition of large quan- tities of oxides, about the same expansion as the cast-iron culi- nary vessels, to which they were chiefly proposed being applied. 246 REPORT—1840. They are of very limited application, and appear to present a good deal of technical difficulty. 204, These somewhat scattered facts, in the chemical history of paints and preservative varnishes, are little more than suffi- cient to show us the barrenness of this region of art, which has received no cultivation as yet but that of continued tentation on the part of the workman, undirected by scientific principles. Much might be hoped for, important in technical results, by the enlargement and correction of our still defective knowledge of the organic chemistry of the fixed and volatile oils, the resins and the bitumens. ‘To paints or varnishes alone, however, we are not to look for the means of complete protection from cor- rosion for oxidable metals; their liability to removal by slight external forces precludes this; their proper place, as mechani- cal protectors, will be found subsidiary to those which are de- pendent on chemical or electrical relations ; and one of their most important uses will probably be found in their application, in union with substances poisonous to animal and vegetable life, to the bottoms of iron ships, to prevent the “ fouling’’ produced by their accumulation, and now found of so much incon- venience. 205, At the period of publication of the previous report, the preservation of cast and wrought iron, by the electro-chemical action of zinc, was beginning to excite that attention which was first drawn to it by the views of Sir Humphry Davy, and the subsequent experiments of Prof. EK, Davy; but there had not been time to enable any very decided results to be given in that report. I am now, however, in a condition to state the results of a tolerably complete train of experiments made on the protective powers of zinc, to iron and steel under various circumstances, some of which have been continued for upwards of two years. The experiments I have made on the electro-chemical power of protection of zinc to iron are divided into two great classes— those in fresh water and those in sea water; and each of these classes again divides itself into two, namely, those made with the preserved and preserving metals submerged to a greater or less depth in the fiuid, and those in which the metals were ex- posed freely to air, and covered by an indefinitely thin film of water constantly renewed, or, in technical language, to ‘‘ wet and dry. In each of these conditions experiments have been made on the protecied metal, in presence of zinc in a massive form in simple contact, through the intervention of the solvent or fluid in which both were immersed, and also when the pro- tected metal has had voltaic contact established with the zinc by ON THE ACTION OF AIR AND WATER UPON IRON. 247 actual union, or, as I shall call it, 2 metallic contact, as in the case of zinked iron, or iron coated with zinc at its fusing temperature. Hence there have been made eight distinct trains of experiment on this one branch of the subject, each of which has been carried on upon cast iron, upon wrought iron, and upon steel, as the following scheme will serve to indicate : All freely exposed to air and carbonic acid. Tn sea water. In fresh water. In sea water. In fresh water. Tn sea water. In fresh water. In sea water. In fresh water. In sea water. In fresh water, In sea water. In fresh water. In sea water. In fresh water. In sea water. In fresh water. In sea water. In fresh water. In sea water. Submerged 12 inches ......... Cast iron and zinc. In simple contact.. Submersion indefinitely stall { Submersion 12 inches ......... In metallic contact. Submersion indefinitely small { Submersion 12 inches ......... In simple contact.. Wrought SGA indefinitely small iron and zine. Submersion 12 inches ......... In metallic contact | Submersion indefinitely small { Submersion 12 inches ......... In simple contact.. Cast steel Submersion indefinitely small ipa and 4 n fresh water. zinc, Submersion 12 inches ......... obs Vier In fresh water. Jn sea water, In metallic contac | In fresh water. Submersion indefinitely small { I will not venture to enter here upon the lengthened detail of these experiments, which will probably appear in a more suitable place, but merely state the method and principal results ar- rived at. 206. The fresh water used in all these experiments was that which supplies the city of Dublin at the north side; it comes from Lough Ouwell, ina limestone district, county Westmeath ; it contains no solid matter when filtered, but a trace of car- bonate of lime and of carbonate of iron. It holds in combina- tion, however, one volume in eight of gases evolved on boiling, which consist of umtospheric air J ers PY Fo olgasy Ramee cic, .4) OYERMUEE Ae I See MOTE a ee) 100°0 cubic inches. The sea water used was invariably that from Kingstown Har- bour, of which the analysis has been already given. 248 REPORT—1840. All the experiments were carried on with water and air at about 62° Fahr. The cast iron is that of « 77, (Table No. I.), or hard gray, mixed, Welsh and Scotch iron. The wrought iron, No. 2, Welsh bar, and the steel () cast steel, of the Mersey Steel Company’s make. The depth of im- mersion in all the submerged experiments was uniformly twelve inches, in glass vessels. The zinc used was nearly pure. The volume of water employed in each experiment was fifty cubic inches. Of Cast Iron in simple contact with Zinc immersed in Fresh Water. 207. If cast iron be perfectly free from any initial stains of rust, and quite homogeneous in texture, it is electro-chemically preserved by the contact of an equal surface of pure zinc, for an indefinite period, during which the zinc is oxidated, the oxide of zincistransferred to the surface of the iron, and forms mammillary concretions on it; after which the protective power of the zinc is greatly diminished, and at this stage the contact of any sub- stance, even a neutral one,—such as glass with the iron,—is sufficient to originate oxidation upon it, which, once established, gradually extends, without the zinc having power to arrest it. The oxide of iron produced has the composition (Fe O + Fe, Og) +HO*. 208. If cast iron, having a polished surface, be suffered to contract any coating of rust, although the surface be afterwards perfectly polished to the eye, yet zinc, in simple contact, has lost nearly the whole of its power of protection ; the zinc and iron both oxidize from the moment of immersion. If the surface be removed by the file to some depth, however, the remaining metal is preserved. 209. If wrought iron has been exposed to solvent action in contact with a powerfully electro-negative metal, as copper or mercury, for a considerable time, and its surface be then removed, even to the depth of 5th of an inch, or more, with the file, and immersed in contact with zinc, the latter is found to have lost nearly all protective power with respect toit. Cast iron so cir- cumstanced corrodes from the first moment, and the oxide is de- posited in tubercles. 210. On the other hand, if wrought iron, a portion of whose * The formule used for these oxides have respect merely to composition, and not to proportion, which varies with the duration of exposure. ON THE ACTION OF AIR AND WATER UPON IRON, 249 surface has been in metallic contact with zinc, or other more powerfully electro-positive metal, while immersed in a solvent, have its surface removed by the file to the depth of 3.th of an inch or more, and be then immersed alone in fresh or sea water, oxidation does not take place at all for a considerable time, and only forms at length in minute detached tubercles. 211. Thus it appears that wrought iron, which has been for a length of time in contact with an electro-negative metal in pre- sence of a solvent, acquires an electro- positive polarity, while that which has been so circumstanced with an electro-positive metal, acquires an electro-negative polarity. The same phenomena do not present themselves with cast iron to the same extent, but yet are discernible. To this curious subject of electro-polarization, Dr. Andrews’s experiments on bismuth and platina supply analogous instances ; and an interesting paper on the same, as effecting copper and platina, has been much overlooked in the thirteenth volume of _ the Journal of the Royal Institution, p. 200. I introduce these two last experiments (209. 210) here for the purpose of remark- ing, that no piece of iron which has before been used for any such experiments as the present, should be used again for a different one. Before becoming aware of this, I was tormented with anomalous results, 212. I stated in my previous report, that the views of Payen and Dumas, viz. that the cause of tubercular corrosion was a slightly alkaline reaction of the corroding water, seemed to me unnecessary to account for the phenomena. Iam now enabled to state, that the sole essential circumstance to tubercular corro- sion is want of homogeneity in the metal corroded, and that I have obtained the most marked tubercular corrosion of cast iron in pure distilled water, and in acidulous fluids. The corroding agent must, of course, be such as will not dissolve the oxide pro- duced ; and it must be admitted, that all other things being the Same, the presence of an alkali greatly exalts the tendency to tubercular deposition of oxide, which may, however, take place without it. Of Cast Iron in simple contact with Zinc immersed in Sea Water. 213. Cast iron, perfectly free from initial rust, is perfectly preserved from oxidation in sea water by an equal surface of zinc. The latter is oxidated; but the oxide formed is not transferred to the surface of the iron, nor does it adhere to that of the zinc: it is washed away in a flocculent form, and is partly dissolved by the saline contents of the sea water. 250 REPORT—1840. Yet, after the lapse of a considerable time, the whole surface of the zinc becomes covered with a thin, black, hard crust of sub-oxide, on which are deposited minute crystals of cale spar, produced by decomposition of the salts of lime in the sea water. When this has taken place, the protective powers of the zinc are greatly diminished, or nearly destroyed. Of Cast. Iron in simple contact with Zine at an indefinitely small depth in Fresh Water. 214. Cast iron, free from initial rust, so exposed in contact with an equal surface of zinc, is oxidized from the first moment of exposure. The zinc is oxidized also, and the oxide forms concretions at the point of contact of the metals, and increases the oxidation of both metals ; so that of two equal surfaces of cast iron, exposed during equal times to an indefinitely small depth of fresh water, the one alone, and the other in simple con- tact with an equal surface of zinc, the latter will lose the greater amount by oxidation. 215. When cast iron, free from initial rust, is exposed to an indefinitely small depth of sea water, in simple contact with an equal surface of zinc, its oxidation is retarded, but not pre- vented, and after a time takes place, as in the last case. Of Wrought Iron in simple contact with Zine immersed in Fresh Water. 216. Wrought iron, free from initial rust, exposed in contact with an equal surface of zinc, is preserved from oxidation until a large amount of oxide of zinc has concreted at the point of junction of the metals, when the iron gradually begins to form tubercular points of oxide on its upper side. The oxide has the composition (Fe O0+Fe, O;)+H O. Carbon is deposited in microscopic crystals on the zine. 217. Wrought iron, under the same circumstances as above, but immersed in sea water, is preserved for atime. But although the oxide of zinc deposits on the iron with greater difficulty in sea than in fresh water, yet it does so at length, along with cry. stals of cale spar; after which the protection of the zinc becomes uncertain, and is disturbed by the contact of any neutral solid. | Of Wrought Iron exposed in simple contact with Zinc at an indefinitely small depth in Fresh Water. 218. When wrought iron, free from initial rust, is exposed thus, in simple contact with an equal surface of zinc, oxidation commences at once, and proceeds rapidly. The zinc is oxidized also, and the oxide of zinc adheres to the points of contact of ON THE ACTION OF AIR AND WATER UPON IRON. 251 the metals in mammillary concretions. The oxide of iron formed has the composition (Fe 0+ Fe, O,)+ (Fe 0+C O,)+HO. 219. When wrought tron is exposed under the same circum- _ Stances as above, but to sea water, the same phenomena as in _ the last case present themselves, but much more slowly, much _ of the oxide of zinc being dissolved in the sea water. : Of Cast Steel exposed in simple contact with Zinc, immersed ; in Fresh Water. | 220. When cast steel, free from initial rust, is exposed in simple contact with an equal surface of zinc, the general surface _ of the metal remains bright, but tubercular oxidation gradually Sh place at the points of junction of the steel and zinc ; the tter oxidizes less as this proceeds, and finally ceases to protect the steel at all. Carbon is transferred from the steel to the surface of the zinc. The oxide formed has the composition (FeO+F,0,)+H O. _ Of Cast Steel in simple contact with Zinc immersed in Sea Water. __ 221. In this case, the same phenomena take place as in the last, but much more slowly. definitely small depth of Fresh Water. _ 222. Cast steel, free from initial rust, thus exposed in sim- ple contact with an equal surface of zinc, soon begins to rust in regular patches. ‘The zinc also oxidizes, and the oxide forms Concretions at the points of contact ; after which the steel ox- es still faster, so that in equal time it loses rather more by oxidation than an equal surface of cast steel, exposed as above, simple contact with an equal surface of zinc to an indefinitely mall depth of sea water, the same phenomena, as in the last present themselves, but much more slowly. 0) Wrought Iron in metallic contact with Zinc, or Zinked Iron.— Of Zinked [ron immersed in Sea Water. 224. A plate of zinked iron was immersed for twenty-five iths in sea water; its whole surface was zinked. On ex- tion, the surface was covered with a hard black coat of sub-oxide, over which was a thin coating of crystalline car- Donate of lime, but no symptoms of oxide of iron were to be 252 REPORT—1L840. seen. Very little of the zinc was dissolved, and a little loose oxides were in the bottom of the glass jar, which proved to be eta CO,)+ (CaO+CO,) +(FeO + Fe, O,) + (ZnO + Fe,O5) + : 225. A plate the same as the foregoing in all respects, im- mersed the same time in a saturated solution of common salt, on examination presented the same phenomena, but less strongly marked. Of the ratio of Zinked surface to that of Iron necessary to protect the latter, immersed in Sea Water. 226. When equal parallelopipeds of partially zinked iron are immersed in sea water, having the following ratio of zinked surface to that of the iron, viz. Zinc Surface. Tron Surface. a ASO) (ecw ec) tis : oak shh togee B ZOOM Os PP : oes an Y TOO Ae - ri WH 8] | ) On2 oie es 2 esr BEE: € Ole. *. ung stom c 0:065 ste : se? eel! n OrOSTZ5: Ney : a Mek Mepil O 2B SM.. WOFOL5625 or > Seng Lae ey its ROOT OOrar as : odacher al the zinc is rapidly oxidized in all, and the amount of oxide of zinc formed is in the ratio of the surface of zinc exposed ; the other, or e—, elements being all of equal surface. The oxide of zinc formed is flocculent, and does not collect either at the iron or zinc poles, and is partly dissolved by the sea water. The iron remains bright and free from oxide, with every pro- portion of zinc, down to the ratio of 0°00786 :: 1 of iron. Hence the limit of protective power of zinc in metallic contact with iron immersed in sea water is between ;1,th and ;3,th of the surface of the latter, at which point oxidation takes place rapidly. Of Iron in metallic contact with Zine immersed in Fresh Water. 227. When several equal parallelopipeds of iron are immersed. in fresh water, having the following ratios of zinked surface to. that of iron, viz. ON THE ACTION OF AIR AND WATER UPON IRON, 253 Surface of Zinc. Surface of Iron. UA OOYM hes or : sth Met tha, or EO OS eet -Fatsy 5 anit Bile Ay gm cratic tap 010 Jed are Re : Baiiaph tare SUPER SAAN eam “lat : Siena: howe =the 0 DS ea be . ere eaers eS Watery te A OROGS, te een’ ae ts St ee SOROUST 2S Ser. = Py desig eee SOONG Zhe ; SR Sue. OOO786 0%, : hh ig sk 1 4 ona OS = & ell ee El ee the zinc in all is corroded, and the amount of oxide formed in equal times, is proportionate to the surface of zinc ; the other, or e—, elements being equal. The oxide of zinc is deposited on the zinc pole in mammillary concretions. The iron remains bright and free from oxide, with every proportion of zinc, down to the ratio of 0°103125 of zinc :: 1 of iron; with this and below it, tubercular oxidation takes place on the iron surface to an extent in equal times proportional to some unascertained function of the surface of zinc. 228. Hence it is proved that at the depth of immersion of all these experiments, viz. twelve inches, the limit of protective power of zinc in metallic contact with iron in fresh water lies "between =1,th and #,nd of the surface of iron; or that it re- quires about four times the amount of zinc surface to put in motion the same quantity of electricity, and thus to protect “wrought i iron in fresh water by its aid that will effect this result ‘in sea water. But after the lapse of a considerable period in fresh water, all the other parallelopipeds began to show signs of rust or of tarnish in the inverse order of their respective surfaces of ‘zinc ; hence time alone seems requisite in fresh water to cause the protective power of any amount of surface of zine for iron ‘to cease, which is confirmed by the following fact. _ 229. A plate of iron, whose entire surface was covered ‘with zinc in metallic contact, was immersed for twenty-five months in fresh water. On examination, much flocculent oxide of zinc had been formed, and lay in the bottom of the glass yessel, which was in some places stained with red oxide of iron. The zinc surface was found in irregularly scattered patches, wholly removed down to the iron, which was covered with per- oxide. Hence about two years appear to be the limit of pre- Servative power of zinc to iron in fresh water, applied in fusion over its wholesurface by the ordinary method. Itis to be noticed, that the zinc surface was removed by solution, unequally or in patches, indicating local action ab initio; and it has been before 254 ' REPoORT—1840. shown, that as soon as oxidation takes place at any point upon the iron surface, the protective power of the zinc is at once diminished, or rendered null. Of Iron in metallic contact with Zinc exposed to an indefinitely small depth of Sea Water. 230. When several equal parallelopipeds of iron, having the following ratios of zinked surface to those of iron, viz. Surface of Zinc. Surface of Iron. a 4:00 3 evauas) geaeael b P00) iWon ae ; - abel c SOOT, ear. Fane : ae Tei es d a EO OS ey ee z 2 He | e Sy a I eet arg” Ag : alba ll ell af 2 OOo s | le : eee Oh a | g 0-13125) 2. : Aaa fe La dl | h 0°015625 F 4 Pade sak 4) | z 0O;00786 . . : ] are exposed to an indefinitely small depth of sea water, the iron remained bright and free from oxide, down to the ratio of 0°065 of zinc to 1 of iron; but in all below this the iron suffered ox-- idation tubercularly. The oxide of zinc formed did not adhere to either the iron or the zinc, and was partly precipitated in a flocculent form, and partly dissolved in the sea water. Within the period of experiment the limit of protective power of zinc in metallic contact with iron, under the present condition, lies between nd and ;4,th of the surface of the latter. Of Iron in metallic contact with Zine, exposed to an in- definitely small depth of Fresh Water. 231. When several parallelopipeds of iron having the follow- ing ratios of zinked gurfaces to those of iron, viz. Surface of Zinc. Surface of Iron. td a peepee perp: rie Ni | ap, EES he RREE Sa 6. Me eae se wists ols LUO LS CY FRE A TAO) “ENGELS SS IT SA, 25! are FR aa ies emo Lo) Riis se were exposed to an indefinitely small depth of fresh water, oxide of zinc was formed from the moment of exposure, on all, which formed hard mammillary concretions on the surface of the zine, and also in isolated centres on that of the iron; but from the ratio of equal surfaces of zinc to iron, up to the proportion ell peel eel oe Il ate » > ; f Ss r ON THE ACTION OF AIR AND WATER UPON IRON. 255 of thirty times the surface of zinc to that of iron, complete electro-chemical protective power could not be procured even for a few hours. With equal surfaces of zinc and iron the latter became red-rusty in twelve hours, in tubercular masses, the oxide formed having the composition (Fe O + Fe, O;) + HO. 232. From the foregoing series of experiments on the re- actions of fresh and sea water on iron and zinc, besides the - immediate facts obtained, we are in a condition to make some general deductions. It has been shown that the oxidizing _ effect of fresh water, holding one volume in eight of air and carbonic acid, is much greater than that of sea water, holding i one volume ms seventy of air and carbonic acid, on cast iron, _ wrought iron, and steel, in voltaic contact with zine, all other _ things being the same ; this arises from two circumstances—the : difficulty with which a saline solution absorbs air when once robbed of it, but still more from the fact, that the oxide of zinc f formed plays a very different part in sea water to what it does in fresh water. Mi, 233. In sea water the oxidation of the zinc produced oxide (Zn O), and at length a coat of suboxide, which forms a dis- tinct ort gray layer on the zine surface, and may be detached _ on bending the metal so as to obtain the suboxide in a state of complete insulation from admixed metal, but none of the first adheres to the metallic surface ; the oe of the oxide of zinc _ formed is either washed away in a pulverulent form, or is dis- _ ‘solved by decomposition of the sulphates, bromides, and chlo- t rides of the sea water, forming sulphate, bromide, and chloride _ of zinc, while the lime and magnesia form, with absorbed car- _ bonic acid, insoluble carbonates ; or if the iron be peroxidized, _ the oxide of zinc forms in part a saline double oxide with the : sesquioxide of iron; but the zinc surface is preserved clean and uniform to the last, either in the metallic state or as a sub- oxide, except when the reaction has been very slow and the electrical current very feeble ; in which case, after the lapse of a long period, crystals of calc spar form on both metals. 934. Not so, however, in fresh water; here the oxide of Zine undissolved forms local concretions of oxide on the sur- face of the metal already covered with a coat of suboxide. ‘Now the precise condition constituting a suboxide, as Berze- Tius has well remarked, is to be decomposed, under the play of very slight affinities, into protoxide and metal, as in the ana- logous cases of the suboxides of copper, Dianaith: arsenic, &c., at each local centre of deposition, then of protoxide of zinc, the suboxide is so decomposed in fresh water, attended with Pps 256 REPORT— 1840. decomposition of the water itself; hence results local action on the zinked surface, between the portions of it in the metallic state and in the state of suboxide or protoxide; and hence its removal in patches, by which the iron is soon laid bare in spots, on which, when once peroxide of iron has formed toa certain extent, the protective power of the remaining zinc is at an end; for as has been shown*, the original difference in electric condition between clean iron and clean zine is so small, that the former ceases to be negative with reference to the latter as soon as it has been rendered more positive by the pre- sence of its own peroxide. 235. We have seen that the conditions the most favourable possible for rapid oxidation of iron consist in its exposure to ‘* wet and dry,” or to air covered with an indefinitely thin film of water constantly renewed ; thus circumstanced, zinc has no protective power over iron in fresh water ; and on the whole it may be affirmed, that under all circumstances zine has not yet been so applied to iron to rank as an electro-chemical protector towards it in the strict sense; hitherto ithasnot becomea prevent- ive, but merely a more or less effective palliative to destruction +. 236. There are some contingent circumstances in the re- actions of zine and iron, in presence of air and water, which require a brief notice. All the surfaces of a parallelopiped of iron, in contact with zinc, do not lose alike by oxidation; in these circumstances, that surface which is nearest to the source of absorbed atmospheric air, especially if it be parallel to the plane of the surface of the fluid, loses the most by oxidation in a given time. 237. All other circumstances being equal, the upper surface of a parallelopiped of iron loses more in a given time than either of the others. The reason of this is, that the bubbles of — hydrogen escape freely from the upper surface as soon as formed, and leave it constantly exposed to the action of the air and water; but they cling to the lateral and under surfaces, and so defend them more or less from the reaction. The same result is frequently observable in a piece of iron exposed to a moist atmosphere, but from a different reason ; here, zn general, dew deposits first and most copiously on the upper surface, and * § 207. + It is scarcely therefore necessary to notice, in way of contravention, a paper in Poggendorff’s dAnnalen for last year, vol. xlvii. p. 213, giving an account of the complete preservation of certain salt-pans by bands of zine, which are said not to have been in contact with the saline solution. The paper in question is a curious instance of the “ sophisma non causz pro causa.” A recently-boiled saturated solution of common salt has no action on iron, whether zinc be present or absent. ON THE ACTION OF AIR AND WATER UPON IRON. 257 hence it is the more moistened, and therefore the more cor- roded. These modifying conditions apply, whether iron be in contact with zinc or not. 238. Water is always decomposed by iron or zinc in metallic contact as soon as oxidation of either metal has commenced, and hydrogen is at first absorbed by the water, and when this is saturated, evolved; but oxidation will not commence at all either on metal in an hermetically sealed vessel of water free from air, or on a body acting inits capacity as a peroxide. Hence, while air is constantly requisite to maintain the power of de- composing the water, it is not by the decomposition of the air alone that the iron or the zinc is oxidized, as was maintained by Dr. Marshall Hall*. 239. In my former Report+, I alluded to the effect of covering surfaces of neutral solids, as glass, &c. (beneath which the solvent fluid penetrated), in arresting corrosion. In the progress of these experiments, however, I have observed some curious modifications of this condition. 240. If a clean surface of iron immersed in water be covered with a parallel surface of plate glass, leaving a film of water between, oxidation will not take place between the glass and the iron, at least for a great length of time; it very gradually creeps inwards from the edges, forming patches of green inter- mediate oxide ; but if in place of the plane of glass a glass lens of large curvature, and thus making very small angles with the surface of the iron, be placed upon it, oxidation will commence at the point of contact, and will spread from thence, although the iron may be in such a condition, that if no glass or other neutral solid were in contact with it at all, oxidation would _ just not take place. 241. So that, in general, whether a neutral solid prevent or _ promote oxidation, depends upon its position in relation to the surface of the metal. This fact seems to belong to the as yet not understood power, in promoting chemical action, which extremely small orifices or fissures seem to possess, as in the action of spongy platina, of pyrophorus, of porous bedies in _ the condensation and the diffusion of gases, endosmose and exosmose through capillary tubes, and so forth. It has long _ been observed, that in a crystallizing solution, crystals first form at acute angles and on salient points. 242. If a plane of polished iron, or other oxidable metal, be fixed, forming a very acute angle with a plate of glass, ivory, &c., and both plunged into water, oxidation commences at the angle first and spreads from it, whatever be the position of the * First Report, § 11. + § 121. 1840, S 258 REPORT—1840. angle with reference to the horizon. If the angle be formed by two planes of iron, the same results follow. If a cut be made on a plate of polished steel with a diamond, oxidation takes place there first. Hence, in general, a rough plate of iron or steel will be acted on by air and water sooner than a smooth or polished one; and thus we perceive, in instruments of pre- cision, the value of a well-polished or burnished surface. 243. The well-known difference in rapidity of solution be- tween pure zinc and that containing an alloy of another metal in small quantity, first noticed by De la Rive, induced me to make a few experiments as to whether the protective power of zinc to iron could be exalted by alloying the former with a mi- nute quantity of another metal, higher or lower in the electro- chemical scale. The following alloys were accordingly made, and equal surfaces of cast iron submitted to the action of sea water, immersed in metallic contact with these, viz. 50 Zn + Hg 100 Zn + Ap 25 Zn + Cu 50 Zn + Cu 100 Zn + Cu 50 Zn + Sn 100 Zn + Ni 25 Zn + Fe 100 Zn + Na and also with pure zinc, and alone: on examination, it was found that the alloy, in minute quantity of every metal which is electro-negative to zinc, when in contact with cast iron, in- creases its corrosion in sea water, including the alloy with iron itself. While the alloy in minute quantity of a metal electro- positive to zinc increases its protective power to iron, or de- creases the corrosion of iron in sea water when in contact therewith ; we shall hereafter see reason to conclude these alloys not to be definite combinations, at least of their entire mass, although fused together in atomic proportion, but mixtures of definite alloys with a great excess of zinc. 244. I now proceed to notice the results contained in Tables IX. and X. These tables indicate the amount of corrosion of cast iron in sea water, when exposed in voltaic contact with various alloys of copper and zinc, and of copper and tin, or with either of those metals separately per unit of surface. The alloys in Table 1X. of copper and zinc, belong to the class of those generally called brass, those of Table X. to those usually denominated gun-metal. ON THE ACTION OF AIR AND WATER UPON IRON, 259 The primary object of these two series of experiments was to determine, in all its generality, the question as to the pre- servative or non-preservative power of brass or gun-metal to iron in sea water, a statement affirmative of which, it will be recollected, was made at the meeting of the British Association at Liverpool. This question has been pretty fully discussed in my previous report, and it was therein shown that neither brass nor gun-metal, as commonly so called, had any protective power (of an electro-chemical character) over iron in water, but, on the contrary, promoted its corrosion. The few experi- ments on which this limited conclusion was made, were tried on alloys of uncertain, or at least non-atomic constitution; it was desirable not merely to set the question of protective power finally at rest, but to establish a set of practical data for the engineer as to the actual amount of increment or decrement of corrosion of iron due to the presence of various alloys of the orders brass and gun-metal, when immersed in sea water. 245. It is obvious that this question is only a particular case of a much more general one, namely, if there be three metals, A, B and C, whereof A is electro-positive, and C electro-nega- tive with respect to B, and capable of forming various alloys, A+C, &c.; then if B be immersed in a solvent fluid in pre- sence of A, B shall be electro-chemically preserved, and A cor- roded, and vice versd. If B be so immersed in presence of C, B will be dissolved or corroded, and C electro-chemically pre- served, the amount of loss sustained in either case by the posi- tive metal being determined according to Faraday’s general law of volta equivalents. But now let various alloys be formed, having atomic constitu- tions, as 2 A+C, A+C, A+2C, &c., and let B be exposed tothe same solvent in presence of each. Query, what will be the electro-chemical relation of the metal B to each alloy, in respect to preservation, or amount of loss by corrosion? and what will be the nature and amount of the reactions of several such alloys upon an acid or saline solution, of a third metal, or of either _ of those constituting the alloys? thus, 246. When the metals, zinc and lead, and their alloys, having _ the compositions (4Zn + Pb), (3Zn+ Pb), (2Znu-+ Pb), (Zn-+ Pb), - (Zn +2 Pb), (Zn+3 Pb), (Zn+4 Pb), are immersed under simi- lar circumstances in a solution of acetate of lead, it would be presumed that the decomposing power of every alloy would be in proportion to the quantity of zinc enter ing into its composi- tion. The result is not so, however. The zinc and the alloys (4 Zn + Pb) and (3 Zn + Pb) at once reduce the lead of the acetate of lead to the state of metal, ang as rapidly as zinc alone; after s 2 260 REPORT—1840, the lapse of some days, the alloys (2 Zn+Pb), (Zn+Pb), and (Zn+2 Pb) have reduced a few scattered crystals of lead; but the remaining alloys, (Zn+3 Pb) and (Zn+4 Pb), act in all re- spects precisely as the lead itself towards its own salts. 247. When a similar set of alloys are placed in a solution of nitrate of copper, a metal which is reduced from its salts both by zine and lead, then the zinc and the alloys (4 Zn+ Pb) and (3 Zn+ Pb) reduce the nitrate to metal, and the lead does so likewise. The alloys (2 Zn+Pb), (Zn+Pb), and (Zn+2 Pb) reduce the salt to deutoxide and metal mixed; but the alloys (Zn +3 Pb) and (Zn +4 Pb) reduce the nitrate to deutoxide alone, without reduction of metal. From the relations in affinity for oxygen between copper, zinc and lead, it was to be presumed, that all the alloys of the two latter metals would reduce copper; but it is remarkable that all the alloys between (2 Zn+ Pb) and (Zn+4 Pb) have less power of reduction than lead alone, while the alloys (4 Zn+ Pb) and (3 Zn + Pb) have at least equal power with zinc alone. Analogous phenomena occur when solutions of other metals, reducible by either zinc or lead, are used; and also when other metals, as the alloys of copper and zinc, or copper and tin, are em- ployed, so that no prediction can be made, from the known affini- ties of the component metals towards a saline solution, what shall be the affinities towards the same solution of their atomic alloys. 248. In this class of reactions it by no means always happens, that both metals of the alloy, although both separately soluble in the electro-negative element of the saline solution experimented on, are dissolved in the ratio in which they exist in the alloy ; nor is it always the most electro-positive metal of the two of which the largest amount is dissolved. The presence of each metal, and of its oxides, affects the affinities of the other of them, instances of which we have in the alloy of silver and platina, soluble in nitric acid, &c. As, however, the treatment of the general question of the action of alloys, when immersed in acid or saline menstrua on the solvent, and on each constituent metal, does not properly belong to the present subject, and a sufficient general indication of their bearing upon it has been given, I re- serve the details for another occasion, and pass on to remark the practical uses to the engineer of Tables IX. and X. 249. In Table IX. it will be seen that the twelfth column gives the amount of loss per square inch of surface of cast iron, with the skin removed by turning or planing (during a period com- parable with all the preceding experiments), in contact with brass, and various analogous alloys of zinc and copper, and also with copper and with zinc singly. Thus the engineer is enabled ON THE ACTION OF AIR AND WATER UPON IRON. 261 to predict the amount of loss any piece of submerged iron- work will sustain in a given time by corrosion, when brass, &c. enters as part of the construction, as, for instance, in the rollers, chain- boxes, paddle-sluices, &c. &c. of dock-gate work. It will be seen that cast-iron alone, similarly circumstanced to all the rest (No. 24), suffers a loss in sea water, as compared with an equal surface of cast iron in contact with copper, as 8:23: 11°37; that is, the copper, as might be expected, largely promotes the corrosion of the iron; but the Table also shows, what would ot have been expected, that the alloy having the composition (7 Cu+Zn), promotes this corrosion still more powerfully, or in the ratio of 13°21: 8°23, so that the addition of this amount of an electro-positive metal to the copper actually produces an alloy (a new metal, in fact), with higher electro- negative powers in respect to cast iron than copper itself. The Table shows that copper, and every alloy of it, with zinc, from (Zn+10 Cu) to (17 Zn+8 Cu) inclusive, are electro-negative with respect to cast iron; but that every alloy from (18 Zn+ 8Cu) to (5 Zn + Cu) inclusive, with zinc itself, are electro-positive with respect to cast iron. Now the last but one of the electro-nega- tive alloys is that (2 Zn+Cu), which is the usual composition of British brass of commerce, which, while it does actually by its presence increase the corrosion of iron by menstrua, thus fortunately does so in a small degree, as compared with other al- loys containing more copper. 250. It will be perceived that the alloys from (17 Zn +8 Cu) to (23 Zn+8 Cu) form a separate interpolated series, advancing each by one eighth of an atom, and differing by only a single atom of zinc from the alloy (2 Zn+Cu) which precedes, and from that (3 Zn+ Cu) which follows. This was needed, and prepared after the formation of the other alloys, in order to discover the alloy of no action, as it may be termed, or that which, in presence of iron and a solvent, would neither accelerate nor retard its solution ; and accordingly we see it lies between (17 Zn+8 Cu) and _ (18 Zn+8 Cu), the former being slightly electro-negative, and _ the latter slightly electro-positive, with respect to cast iron. 251. It was stated in the former report, that the really import- ant direction in which to look for protection from corrosion of _ iron in water was indicated by some results of Schonbein, An- drews, Payen and other experimenters, ard that the problem was ‘‘to obtain a mode of electro-chemical protection, such, that while the metal (iron) shall be preserved, the protector shall not be acted on, and whose protection shall be invariable*.’’ This view Professor Schénbein himself, in a paper presented to * Report, § 136. 262 REPORT—1840. the Chemical Section of the British Association at Birmingham, passes summary judgment upon, by affirming that ‘the con- dition, sine gud non, for efficaciously protecting readily oxidable metals against the action of free oxygen, being dissolved in fluids, is to arrange a closed voltaic circle, made up on one side of the metal to be protected, and another metallic body more readily oxidable than the former, and on the other side, of an electrolyte containing hydrogen—for instance, water.’’ Whatever opinion may be formed as to the necessity of a closed circle, it is un- doubtedly not proved that the evolution of hydrogen is the con- dition of protection, sine qua non; the experiments adduced do not show it, while many others might be quoted directly show- ing it not to be a necessary condition. This is not, however, the place for discussing Professor Schonbein’s views at length, which involve the whole guestio vexata of the chemical and contact theories of galvanism. 252. I proceed, therefore, to notice the seventh column of this Table, in which is given the loss of weight sustained by the alloys of copper and zinc while in presence of cast iron and the solvent. On inspecting this column it will be apparent that the losses have not taken place in accordance ‘with the law of volta-equivalents: there can be little doubt that they are strictly in accordance with that law, and that the results are ir- resoluble from the involvement of two or more series in column seven, arising probably frem some of the alloys being simple binary compounds, and others either double binary alloys, or a mixture of a binary alloy with one or other of its components in excess. 253. It will be further observed, that whereas zinc alone in protecting cast iron suffered a loss of = 2°95 grains, being nearly the equivalent, the alloy (23 Zn + 8 Cu), which as fully protected the iron from all action or corrosion, sustained a loss but of =0°51 grain; in other words, the protecting metal was scarcely itself acted on at all. This, then, makes a by no means unimportant step towards obtaining the much-wished-for electro-chemical protector before spoken of; and henceforth the engineer will have it in his power, whenever the alloy (23 Zn +8 Cu) can be used or applied in contact with cast iron, to protect the latter as fully as by zine itself; yet with a protector which shall suffer scarcely any loss, and whose protective energy I have reason to suppose will be, from this very cause, much more permanent and inva- | riable than I have already proved that of pure zinc to be. 254. With respect to the alloys themselves found in this Ninth and following Table, I believe so large and complete a a at aie a ° Sets jin a aii le vs ed » Sei ON THE ACTION OF AIR AND WATER UPON IRON. 263 - collection of strictly atomic alloys of the two practically impor- tant classes of brass and oe, has not been made hereto- fore. The principal experiments on the properties of this class of alloys published, are those of Margraff; but his were not atomic alloys, nor made in a way likely to ensure a knowledge of their constitution. I have therefore deemed it worth while to make some experiments on the properties of these alloys, and have given the results in Tables XIV. and XV.: as these nearly explain themselves, it is necessary to make but few remarks on them. The alloys of zinc and copper were all made in close vessels; the copper was fused first, the zinc in another part of the same bent wrought iron tube, coated and lined with porce- lain clay and plumbago. The zinc was gradually brought in contact with the copper: the apparatus excluded air, and was continually agitated, until the alloy was poured into a mould of cast iron, in which it was cast into a long strip, which solidified instantly. About seven pounds weight of each alloy were formed at once, and the constitution of each, where any cause of doubt existed, was verified afterwards by an assay. Their composition therefore is rigidly assigned—a circumstance which it is con- ceived gives their properties, so far as they have been ascer- tained, more than usual value. 255, The modulus of cohesion given is higher considerably than those found by Sir John Rennie for copper and brass (2 Zn+Cu), or commonly assigned to zinc. I have no doubt, however, of the present being correct, and the difference arises probably from the superior purity of the metals used by me. 256. The immediate change by the addition of only one eighth of an atom of zinc to the alloy (2 Zn+Cu), from a tough yellow alloy to a white one of extreme brittleness, is very re- -markable. The alloy (5 Zn+Cu), and all the alloys of copper and zine having more constituent zinc than (17 Zn+8Cu) are electro-positive to cast iron, or protect it in solvents ; yet when _ the alloy of copper is reduced to the ratio of (25 Zn+Cu), or (100 Zn + Cu), the compound becomes again electro-negative to cast iron*. These indicate, in a forcible manner, that these _ latter are not simple alloys, but mixtures. It may be added, that the reduction to the law of volta-equivalents of the losses in the seventh column, may enable us to discover what is the constitutional arrangement of the alloys themselves. 257. It should be remarked, before leaving the subject of _ these alloys of Zn+ Cu, that their specific gravities, as experi- * § 243. 264 REPORT—1840. mentally obtained in column five, do not follow the ratio of the amount of copper, increasing as it increases, although their general tendency is towards this; the greatest perturbations take place in the interpolated series(17 Zn + 8Cu)to(23 Zn + 8Cu). These specific gravities are taken on the alloys just as they were cast, and suddenly cooled in the cast-iron mould; but on sub- mitting some of them to lamination, very variable amounts of condensation took place. Hence it is probable that sudden cooling produces an effect analogous to tempering in cold water on the alloys of copper and zinc. Dussaussoy found that as the latter became soft and malleable by tempering (trempe), their specific gravities were reduced in variable proportions ; and it matters not whether this tempering be effected in water, or by sudden cooling in a metallic mould; the alloys now in question have therefore been submitted to this process ; and as no link at present exists connecting the density of such an alloy with its specific gravity after lamination, the densities now given in Tables XIV. and XV. will be found, in most instances, not to correspond with those occasionally given in books, and which have been chiefly made on alloys submitted to compres- sion, or cast and cooled in various ways. The densities given, however, are I believe close approximations to the truth; and all the alloys having been cast in the same way, at the same temperature, and cooled at the same rate, these specific gravities must be relatively correct. 258. Table X. contains the results of the action of sea water on cast iron, in presence of copper and tin, or their alloys. What has been said of the preceding explains the general na- ture of this Table also. It is therefore only necessary to re- mark here, that as copper and tin are each singly electro-negative with respect to iron*, they both, together with every alloy in the Table, increase or accelerate the rate of corrosion of cast iron in a solvent, though in every variable degree. The maximum increase is produced by tin alone ; which in- dicates that tin is more powerfully electro-negative to cast iron than copper, contrary to the opinion previously held. The in- crease of corrosion produced generally by alloys of copper and tin is far greater than by those of copper and zinc: hence the important practical deduction, that when submerged iron-works must be in contact with either alloy, common brass, or copper and zinc is much to be preferred to gun-metal, although con- trary to general practice amongst engineers. The losses on these alloys in column seven, as in the former case, do not apparently follow the law of volta-equivalents. * Report, § 96. ON THE ACTION OF AIR AND WATER UPON IRON. 265 259. The ratio of the surface of the cast-iron parallelopipeds used in these two sets of experiments to that of similar slips of the alloys, is given: both iron and alloys were filed to an ex- act gauge, so as to present strictly equal surfaces, in pairs, and the former made all of equal weight. The amount of loss or the ‘ index of corrosion ’’ of cast iron in contact with any given alloy in the Tables, will of course vary according to some un- ascertained function of the surface of the alloy and of the iron exposed to chemical action. The law regulating this remains to be developed ; it is a subject of considerable complexity and experimental difficulty. The ratio, however, of surface of the electro-negative to that of the electro-positive metal, may vary to a considerable extent without very materially affecting the results given in the present Tables, as respects their primary object. 260. These experiments were necessarily made ina limited " quantity of sea water (12 cubic inches each), and all in separate glass vessels ; and as this water was soon exhausted of much of its previously combined air, the eleventh and twelfth columns in each Table give the ratio of the actual corrosion in a limited quantity of water to that which would take place in an unlimited one, or in the open sea, which is deduced from the result of (# 77) in Table I. first series, being on the same sort of cast iron as the present. _ 261. There are several collateral points of scientific interest this branch of our inquiry presents, which I pass, as out of the “subject of inquiry. I would remark, however, that the results confirm fully what had been previously stated respecting the impossibility of protecting iron by brass in the ordinary sense of the word. They also point out the inutility, not to say the ab- _surdity, of some inventions for the so-called prevention of ox- _idation, for which patents have recently been obtained; for ex- ample, more than one patent, for so preserving iron by dipping it into melted copper *, or coating it with copper or brass in ‘various other wayst. _ 262. It has recently been proposed to substitute zinc for lead in the operation of “ cramping,”’ or running a fluid fusible metal into the joints of iron-works to secure them together, or to _ * Repertory of Arts for 1839-40. __+ lobserve with pleasure that M. Karsten of Berlin has recently published Se lnetitut No. 275, April 1839) some experiments on the electro-chemical re- ations of alloys of copper and zinc, &c., to solutions of their own metals. It is to be regretted that his experiments do not seem to have been made on alloys of atomic constitution; but while unknown to each other travelling (though with different objects) on neighbouring roads, it is pleasant to find that our results have so far brought us to the same resting-place. 266 REPORT—1840. other materials, in order, by taking advantage of its positive re- lation to iron, to save the latter from the increased corrosion due to the presence of lead, which is strongly negative to it. Zinc alone, however, possesses some “disadvantages as a ‘cramping ’’ metal; it oxidates with great rapidity when fused in an open vessel ; it contracts more than lead on solidifying, and it is too rigid to "permit subsequent “ caulking,”’ so as to cause it again to fill the cavity into which it was cast. ‘The results which have been given for the alloys of zinc with copper render it extremely probable, however, that an alloy of zinc and lead might be formed eminently suitable as a “ cramping metal” in contact with iron, which, while it should possess the requisite physical properties, would be found in such a relation to iron as to retard, or at least not promote, its oxidation. 263. In my previous report* I suggested the possibility of preserving electro-chemically, to a greater or less extent, the dense and hard gray cast irons in ordinary use for engineering purposes by means of contact with the softest and most carbo- naceous cast irons, such as those of Scotland and Ireland. I showed that the latter sort of cast iron is, in presence of a sol- vent, constantly in an electro-positive relation to the former, and that of two such specimens of cast iron, in voltaic contact, there was reason to believe that the denser iron would be pre- served to a greater or less extent at the expense of the other. Experiments on this subject have now been in progress for twenty-five months. 264. When four equal-sized parallelopipeds, two of very hard dense bright gray cast iron, just capable of being planed or turned, and two of soft dark gray and highly carbonaceous cast iron, are placed, one of each pair, separately in a jar of sea water, and the other pair (viz. hard and soft) in a jar of sea water together, and in voltaic contact, the pieces having been all weighed, and the sea water preserved at a constant level, &c. &c. Then, after a period of twenty-five months had elapsed, on examination the following were found to be the results as to corrosive action :— All the pieces were found covered with a coat of red oxide, having the composition = (Fe, O;) + (Fe O + C O,) +H O, and much of the same had deposited in the glass vessels. 265. The piece of hard cast iron immersed singly was found, on washing off the coat of rust, clean and pretty bright, and its surface still metallic. On weighing, and also measuring by a micrometer, it was found to have lost a coat of iron over its * § 129. 7 fi ‘ , Be ON THE ACTION OF AIR AND WATER UPON IRON. 267 whole surface of 0°007 of an inch in depth, a result also con- firmed by the amount of rust contained in the vessel, and on the piece when reduced to peroxide. _ 266. The piece of soft cast. iron immersed alone was found, on washing off the coat of rust, to be covered with a thin coat _of soft, unctuous plumbago, capable also of being washed away _by rubbing with the finger; its surface was black, and filled _ with glittering minute scales of graphite, but had lost its me- _tallic lustre wholly. On removing the plumbago down to the _ solid iron, by rubbing with a piece of hard wood and washing, the piece was found to have lost a metallic coat over its whole surface of 0°01 of an inch in depth, estimated as before, and controlled by the amount of graphite and rust reduced to _ peroxide. _ 267. Lastly, the voltaic couple, the hard and the soft iron in contact, were examined; on washing off the rust, the hard ‘specimen appeared bright and polished, and some minute file- marks on its surface, as sharp as when placed in the sea water. The surface of the soft piece of cast iron, on the contrary, was black, full of scales of graphite without metallic lustre, and eapable of being rubbed away with the finger. The two sur- faces, which were actually opposed to each other and in contact, were in both almost quite free from stain or oxidation, where air and water with difficulty gained access, from reasons before explained. On washing and cleaning perfectly the hard speci- men from oxide, and the soft one from oxide and plumbago, and weighing as before, the hard cast iron was found to have Tost a coat of iron over its whole exposed surface = 0:00263 of an inch in depth, while the piece of soft cast iron had sustained a loss over ifs whole exposed surface of 0°03 of an inch in depth, both estimated as before, by weighing and measurement, and the result controlled by estimation of the peroxide and aphite produced. 268. Itis hence proved, that the softest dark gray cast iron is sufficiently electro-negative, to hard bright gray cast iron, to re- d the corrosion of the latter in sea water when voltaically as- ciated with it, to the extent of two thirds of the total amount of corrosion that would be experienced by the same hard gray cast ron, if exposed for the same time and under similar circum- nces alone to sea water, and that the formation of plumbago he softer iron or positive pole, and the collection of a coat ist on the surface of both irons, does not prevent, although may possibly in some degree interfere with, this effect. ence it follows, that while the voltaic relations of soft to hard st iron are such as will not prevent oxidation upon either, it 268 REPORT—1840. is yet in our power greatly to retard the corrosion of the harder iron at the expense of the softer, so that the engineer is thus given a principle of guidance in the combination of different *‘makes’’ or sorts of cast iron in the same structure, when it may be desirable partially to preserve some parts at the expense of others of less structural importance*. Instances of such cases, and of the applicability of the principle here given, will at once occur to practical men. 269. The engineer of observant habit will soon have per- ceived, that in exposed works in iron, equality of section or scantling, in all parts sustaining equal strain, is far from in- suring equal passive power of permanent resistance, unless, in addition to a general allowance for loss of substance by corro- sion, this latter element be so provided for, that it shall be equally balanced over the whole structure; or, if not, shall be compelled to confine itself to portions of the general structure, which may lose substance without injuring its stability. The principles we have already established sufficiently guide us in the modes of effecting this; regard must not only be had to the contact of dissimilar metalst, or of the same in dis- similar fluids}, but to the scantling of the casting and of its parts§, and to the contact of cast iron with wrought iron or steel, or of one sort of cast iron with another||. Thus, in a suspension bridge, if the links of the chains be hammered, and the pins rolled, the latter, where equally exposed, will be eaten away long before the former. In marine steam-boilers, the rivets are hardened by hammering until cold; the plates, there- fore, are corroded through round the rivets before these suffer sensibly, and in the air-pumps and condensors of engines work- ing with sea water, or in pit vork, and pumps lifting mineral - ized or “bad”? water from mines, the cast iron perishes first round the holes through which wrought-iron bolts, &e. are in- serted. And abundant other instances might be given, showing that the effects here spoken of are in practical operation to an extent that should press the means of counteracting them on the attention of the engineer. 270. I have not yet been enabled to extend this part of the inquiry to fresh water, but have reason to suppose it would not be in such case attended with equally striking results from facts before stated with respect to zinc and iron in contact in fresh water ; the same forces, however, still will operate with like results, only differing in degree. It seems not improbable, * Report, § 134. T § 244—261. Pg War § Sect. 179—183. i| § 263—268. ON THE ACTION OF AIR AND WATER UPON IRON. 269 that the softer cast irons might be alloyed with a minute quan- tity of some other metal, which should produce a compound still more electro-positive with respect to hard cast iron than before. This view is supported by some facts recorded by Ber- _ thier, in the Annales des Mines, tom. xi. p. 512, third series. _ Soon after Algiers was taken by the French, some ancient shot and shells were sent to France to be recast, which had been _ discovered in the arsenal. They were found, however, unfit for "service; the metal of which they were composed was full of mi- _ nute cavities, so brittle as to be easily pulverized, white and _lameliar. Analyses of the shot and shells gave the following results in 1000 parts: Shot. Shells. Azsenie)) :5))40) 0. O"27O428s.44.0 O7098 Carborie ae he) 2% POOL es eksieode vo OLS 0°280 0°113 They contained neither sulphur, manganese, calcium, nor sili- ‘con. Specific gravity of shot = 7°650, of shells = 7°585. ‘The cast iron alloy of which they were formed was found by Berthier to oxidate, when exposed to air and water, with un- usual rapidity : he supposes these projectiles to have been cast in Spain, of iron made from mispikel or arseniuret of iron. _ 271. I now proceed to make some remarks upon the specific gravities of cast iron, wrought iron, and steel, which follow in the accompanying tabulated results. In Table XI. are col- _ lected the specific gravities of all the cast irons of the preceding experiments. These specific gravities have been taken with an mnusual amount of care, and by a new method, described in the former Report*, which possesses some decided advan- tages in point of accuracy and convenience. They have all een taken on equal-sized cubes of the several cast irons cut j the planing-machine from bars of equal size, viz. one inch re, and cast in the same way, at the same temperature arly, and cooled at the same rates; all of which precautions _ are essential to procuring correct results. _ 272. Many of my specific gravities do not agree with those iven by Dr. Thompson or those of Mr. Fairbairn, contained heir respective reportst. This may arise possibly from Dr. mpson’s specific gravities having been taken from pieces of raw pig-iron, or castings of a different size from those I d, or of various dimensions with respect to each other. In r. Fairbairn’s case, probably from the circumstance that (as Bs S71: T In vol. vi. Report of the British Association. 270 REPORT—1840. I have heard) his specific gravities were taken by weighing equal bulks ; cubes, in fact, cut from the mass of cast iron by the chisel and file, a method in itself not susceptible of much accuracy, but rendered much more liable to error from the liability to variable condensation of volume of the iron in the processes of chipping and filing; a rough crystalline broken surface effectually prevents an exact specific gravity being taken of cast iron by the usual method of weighing such a specimen suspended in water; and no cutting out of the specimen for weighing by any method is allowable, except by the lathe or planing-machine, which operate so quietly, that no condensa- tion of volume is likely to take place. 273. Dr. Thompson’s results give the specific gravity of hot- blast iron greater than that of cold-blast. Mr. Fairbairn’s, on the contrary, give the specific gravity of cold-blast iron as the greater, and to the latter conclusion my own results tend. I have entire confidence in the correctness of the specific gravities I have given, from the method and precautions taken, and the ac- curacy of the instrument used in the weighings—a balance of Troughton’s construction, readily sensible, when loaded, to the third decimal place. 274. A correct knowledge of the specific gravities of cast iron is important in several respects to the engineer, but most of all so from the fact, that Messrs. Fairbairn’s and Hodgkinson’s ex- periments on the strength of hot- and cold-blast iron seem to in- dicate that the ultimate strength of cast iron is in the ratio of some function of the specific gravity, a view more recently also confirmed by Mr. Richard Evans’s experiments on the strength of anthracite pig-iron. Now the conditions rendering the specific gravity of the same cast iron variable, are I. The bulk of the casting. II. The depth or head of metal under which it has been cast. III. The temperature at which the iron has been “ poured,” or run into the mould. IV. The rate at which the casting has cooled. The determination of the law governing the change in each of these cases is a work of some labour and difficulty, which has been partly attempted. 275. In Table XII. the results are given of the experi- ments I have made on Scotch, Welsh, and Staffordshire cast irons, showing the increase of density produced in large cast- ings at every two feet in depth, down to fourteen feet in depth of casting. These experiments were made on pieces cut at every two feet from a shaft or cylinder of four inches in diameter, cast ON THE ACTION OF AIR AND WATER UPON IRON. 271 vertically, in drysand moulds. They show a very rapid increase at first, and, below four feet in depth, a nearly uniform incre- ment of density, approximating to a common difference of 0°13. No previous attempts have been made, to my knowledge, to ascertain these conditions of variable specific gravity in cast iron : yet their importance is obvious; for if the ultimate strength of castings is as some function of their specific gravity, the results of experiments in relation to strength of castings of different magnitudes, or cast under different heads, are not comparable, unless these conditions of specific gravity be attended to, and in- volved in every calculation. 276. In Table XIII. the results are given of my experi- ments on the decrease of specific gravity of the same cast iron, due to increase of bulk or volume of casting, the circumstances _ of head of metal, temperature and rate of cooling being the same, _ The irons experimented on are Scotch, Welsh and Staffordshire, The bulk of the casting in each successive experiment is double that of the preceding one; and the results show nearly an equal _ decrement in specific gravity in proportion to the increase of _ volume of the casting. These results sufficiently show, for instance, that although the strength of rectangular beams varies directly as their breadth, _ yet doubling the thickness or breadth of such a cast-iron beam will not quite double its strength, as the same iron becomes less _ dense in the larger casting, if so be that we admit a relation be- _ tween density and ultimate cohesion, of which there seems to be _ but little doubt. 277. In Table XI. I have arranged all the cast irons of _ my experiments in classes, according to the characters of their fracture, and, for the first time, attempted to establish an uni- _ form system of nomenclature in this respect, dividing all sorts _ of cast iron, by fracture, into one of six classes, either I. Silvery, II. Micaceous, (miratoire of French authors,) III. Mottled, h- IV. Bright gray, $ V. Dull gray, VI. Dark gray, which will be found sufficient to include and describe every va- _ riety; and it is much to be wished that authors on these sub- _ jects would, in future, adopt this or some similar invariable no- _Mmenclature for the character of fracture, at present usually so ill _ described. 278. The nomenclature, or classification of cast iron by frac- 272 REPORT—1840. ture here adopted, is more also than a mere set of arbitrary visual distinctions, inasmuch as each class I have made holds a constant relation between the character of its fracture and its chemical constitution. Ihave also given the general working character of each such class of cast iron, by which, however, it is not to be understood, but that occasionally a mtxed cast tron may be found, possessing all these characters in working, and yet breaking with a slightly different fracture. The working characteristics given are, however, on the whole, correct. 279. The present communication, I would hope, in some de- gree fulfils the desire of the British Association as to a portion of this inquiry, and will be found not devoid of use to the prac- — tical engineer. I do not purpose to enter at all in the present Report upon the chemical consideration of the changes which iron occasionally undergoes by the action of various solvents in passing into a substance analogous to plumbago, nor of the or- ganic and other products which result from such reactions ; these I hope to bring forward on a future occasion, along with the results of all the other trains of experiment in progress or contemplation, and of the second immersion of all the cast and wrought irons for a period of two years, which will expire in January 1842. The results of their first immersion are now given, and with the results of the experiments now in progress, on wrought iron and steel, together with a review of the whole subject in its purely chemical relations, will, I expect, com- plete our researches. 280. The latter experiments on wrought iron and steel have been for some months in operation ; and the tables of data be- longing to them, which best indicate their nature and extent, have been presented; but it is not necessary to publish them at this time, as the only results of this series actually completed as yet, are the specific gravities. These are given in Table XVI. The maximum specific gravity is that of tilted blister steel, made by the Mersey Steel Company, which is = 7°8461. The minimum specific gravity is that of cast steel in the ingot, be- fore tilting, which is =,7°4413 ; it contains microscopic vesicles. The specific gravity of the iron from which both were made, is =7'5839. From this Table it appears, that both in wrought iron and steel the density is increased more by hammering than by rolling, and that the densest specimens of both metals break with a fibrous or very fine crystalline fracture, while the least dense have a coarse crystalline or lamellar fracture. 281. Experiments already detailed having demonstrated the great rapidity with which iron of every sort is corroded while ON THE ACTION OF AIR AND WATER UPON IRON. 273 “kept just covered with water, or between ‘‘ wet and dry,” a series of new experiments have been recently arranged, contain- ing specimens of cast and wrought iron, freely exposed to all the atmospheric influences, at Dublin. These are coordinate with all the experiments, whose first results of submersion are now given, and will connect the action of water containing air and carbonic acid on iron with that of air holding water and car- bonic acid in suspension, &c. ; and, as the meteorological regis- ters of Dublin are tolerably perfect, will be hereafter comparable with any such made in another locality. The data of this set of "experiments may await the publication of a third report, and be given along with the results. _ 282. Inconcluding this second report upon a subject in which I feel a lively interest, and the practical bearing of which needs ‘no further evidence than the multitude of patents, whether good or bad, for inventions intended to preserve iron, &c., which have ‘been obtained since the publication of the first report, and in “retracing the ground already gone over, I must regret the many imperfections and omissions, which I might have been enabled to avoid, could I have devoted more time to these researches. That learned otium, however, so necessary to successful experimental “study, is denied to those who, like myself, find every day to come preoccupied with the unavoidable duties of a laborious profession. Hence, most of these experiments have been made and recorded in hours stolen from rest, or, with greater difficulty, from busi- ness. _ Ihave to thank many individuals for specimens of iron, &c. N various conditions, and especially my young friend Mr. Charles Scanlan, for his valuable assistance in taking great numbers of specific gravities. 274 Sunk and moored at the Second Buoy in from the Western Pier Head in three Temperature of water 46° Fahr- to 58° Fahr, August 3rd, 1838. Weighed again and landed August 26th, 1839; hence 1840, at one o'clock p.m., and now immersed. Specific gravity of water ordinarily 12 to 16 feet. REPORT—1840. No, of Experiment and mark of Specimen, COONS Or NO RekeRRRRKKRA _ _ 8 — bo Rg al9 a 20 a 24 a 25 TABLE Box a. No. 1. Class No. 1 2. 3. 4, 5. a Specific Commercial Character of Iron. et eater pean roadie, Bins. | Character of | we, | he Wosmis ADSGUIAIS.” \aseccotsaceverscuns: Cold | Dark gray Green 7192 Nols sowlaiss tiiiic.thaedt as sdence Cold | Dark gray | Green 7-183 Nose. SW OULSIS: c RITA ITN SS ASTRO SENS? NOSE — o {4 Pela ta ea oe + alee Hot |Closebright gray| Green 7-168 | Be SCTAP cacevsece | i {# i gan Bal eto Closebright gray| Green 7-168 | 3 eeeeeeeee ‘ ie hence sce sli Hot |Closebright gray| Green 7168 | 3 seen eeee i +4 Dh eae Se tee Hot |Closebright gray} Green 7168 | 3 Scrap ......00. 4.No. 1. Calder + 4No. 2. - : 1 12 Pentweyti 4 Gerap cscssds: Hot |Closebrightgray| Green 7168 Supplementary Table y. Protective Paint or Varnish. State of Covering after 117 days’ exposure. Caoutchouc varnish ...... Oaonancooe Varnish not visible ........csssssesesssesesssees Best white-lead paint...............| Paint stripped off in places.........sescsscssees Copal varnish ............+ sesvscecoee| Warnish nt Visible. ...sescosseccecccseseoes esti Asphaltum varnish.............00+ -.| Varnish scarcely visible. ........+seseesseseenees Mastic varnish .....cscecssessesceeees Varnish not visible. ..........s.c0ccsoscasascssail Swedish tar.......ssseseerseees seeeeee| A trace still remaining ....... ccvccrtecv cca 3 parts wax and 2 parts tallow ...| Converted into adipocere........scescsseseceneee Coal-tar, laid on hot ...............| Still visible in some places .........scseeeeeusee Turpentine varnish.............2+0+ Varnish not visible ....... cabaveas atawaed oocssaan Drying oil ..... scnstarvesesledccscs o«| INOtivisible,....0...sescsscasscassoveorsecuce estan ON THE ACTION OF AIR AND WATER UPON IRON. 289 andard bar of Wrought Iron. ve 8. a 10. 11. 12. 13. Weight of| Total loss Lossof | S Loss of au Weight of | Specimen by Weight | £22 Specimen after a Weisbtner setetrel to SEs Character of in Grains.| 117 dagnt square inch] Standard | 3 2 ‘orrosion. exposure. | 117 nae. of Surface. |." Bar, 5 8 a | | | 24464 | 24274 190 4-318 1:35 0: | Unif. striated. a removed by planing. 6x5x 75 | 34024 | 30750 | 274 | 4:2) | 1:31 | 0: | Uniform. | pr Beected by Paints or Varnishes. PS | “5x5x1 | 42618 | 42594 24 | O84 | -106.).0 | 4. ,» 5x5x1 | 42673 | 42644 SCORN Ss TARE Ge: «|. gamers 5x5x1 | 42457 | 42399 58 | 083 | 259 | o | . he x5x1 | 42075 | 42007} 68 | 097 | 303 | o | , , 5x5x1_ | 42094 | 42004 90 | 1:28 | 368 | o | , 4 jox No. 3. Class No. 8. ' - Order of _ Condition of surface of Specimen after 117 days’ exposure. Protective ; Power. , a Uniform rusting. Surface hard ..........++ chose depen cadaorc 1 ted in spots. Hard. No plumbago aeeee 4 nsound. Minute cavities.......... Moasecpiesveweveer seas eee 2 sound. Hard rust uniformly ........sccecsesccsceceenees 3 ound. Hard uniform rust, ........seceeseeee ascccecco ne 5 Hsound. Uniform rust .......seseecseessecseseees sciweactees 6 still fresh in parts. Rusted in pits ......+s0see00es cece 8 in spots. Plumbago in spots ......sssessesesseseeeeees 7 nbago in various spots 9 edin places. Hard rust uniformly ooeees 10 | 1840, U 290 Sunk and moored in the mid-stream of the river Liffey, at Dublin, opposite —_— . No. of Experiment and mark of Specimen. ww oe ww aon vy =) 310 INO eo) PCHtWYI snccGesuapreseerses- Hot Mottled Green No. 12. “Pentwyl.-se-0s..co0+scesnas. Hot Silvery Chilled | 7:129 | Box 8. No. 4. Class No. 3, No. 2. Apedale. ........++ mcobosnocee Cold Mottled Green 7268 | No. 2. Apedale. ...ccccesssesessseess Cold Silvery Chilled | 7-603 | Box 8. No. 4. Class No. 4% Din. tebs PATINA eves ensarsseccceuades Cold Dull gray Green 7-141 No. 3. Arigna.........+ Skanes ceeenine Cold Mottled Chilled | 7:308— } Box 8. No.4. Class No. 5: Hardest procurable. Old firebars, &c.| ...... Silvery crystals | Chilled | 7:624 4 Wien eoalder INOW icvarcucuccdsnasssne Hot Gloss jnlieeae Te 6-978 + 4 Pentwyn No, 2. ........000+ Hot Se CU NERAy Zeen i REPORT—1840. TABLE Box 8. No. 4. containing Specimens of Cast and Wrought and from fifteen to twenty feet at flood-tide. The water fresh at ebb-tide, from 86° Fahr. to 61° Fahr. Sunk on the 6th of August, 1838, at five hour, having been immersed for 383 days. Again sunk in same place at water = 1002°27. Box 8. No. 4. Class No. ip 2 3. 4 Specific Hot or External Gravity of | Commercial Character of Iron. Cold Character of How Cast, | Specimen } | Blast. Fracture. s} s=— ; = ! ni Orem Galdetiic.sessasecedascusetetens Hot Dark gray | Green 7027 |. INO AU WANGEY cen scepsedes auearessaecw Hot Mottled Chilled | 7:079 Box 8. No. 4. Class No. 24) 7-017 | it ei No.2. Arigna. v.sscccecveeses Cold + 4No. 2. Pentwyn Hot [| Close dull gray | Green 7-050 | : ne ampetion of the Poddle River therewith. . _ Specimen. $ ' re \ ‘ oa 5x5x1 o3x5x1 Scotch Cast Iron. 7. 8. 9. Weight of | Total loss Weight of Spagimnen by Specimen after Corrosion in Grains. | 383 days’ in exposure. | 383 days. 41449 | 41145 304 43295 | 42885 410 { staffordshire Cast Iron. Trish Cast Iron. 42462 | 42181 281 43333 | 42903 430 44976 | 44857 119 43760 | 43478 282 40741 | 40305 436 42675 | 42241 434 44799 | 44473 326 42454 | 42147 307 42318 | 41981 337 U2 f ON THE ACTION OF AIR AND WATER UPON IRON. 297 Depth of water four feet at ebb, 10, Loss of square inch of Surface. 4:34 5°85 4:01 6:14 1:70 4:03 6°23 6-20 4:65 4:38 4:81 11. Loss of Weight per| Weight referred to Standard Bar. ‘A417 562 378 590 163 373 599 598 ‘447 “421 462 absorbed. 2? 2? very brackish at flood. Bottom soft putrid mud. Temperature of water lock p.m. Weighed and landed again on the 24th of August, 1839, at same o’clock p.m., January 13th, 1840, and now immersed. Specific gravity of 13. Character of Corrosion. Local P. Tubercular. Local P. Tubercular. Tubercular. Tubercular. Local P. Tubercular. Tubercular. Tubercular. Tubercular. oo : 292 REPORT—1 840. =] cy Box 8. No. 4. Class No. 6. { I. 2 3. 4 5 , Se Sa eae eae aay Cea ary Sey, — Sad ecific S a aE 2 stent tsoee ye eee " External Getty of ( sEAS Commercia aracter of Iron. ‘Oo haracter of ecimen 58s B Blast. Fracture. ——— =: Ws | As Ke S= } ANS “a —_—— ] 3.12 | No.2. Doulais. Common bar......|..+.000+: Fibrous S 7587 | . Box 8. No. 4. Class No. 7. 1 No. 1. Calder 1 No. 2. 3 313 2 Pentwyn + 4 a +5 ae } Hot |Closebright gray} Green | 7-138 Box 8. No. 4. Class No. 8. 1 No. 1. Calder No. 2. = a |{* Best 4 ea np ae Hot |Closebrightgray; Green 7-168 1 No. 1. Calder 1 No. 2. i | 315 {? Bentwyn 1-4 aus Fa aR Hot |Closebrightgray| Green 7168 | 1 Ne. 1. Calder No. 2. : 316 Sg TEESE ‘i Strap = eae } Hot |Closebrightgray| Green 7-168 | 1 No. 1. Calder + 4 No. 2. : ; | 317 a Pentwyn 4 Scrap ee Hot |Closebrightgray| Green 7-168 | NoJ1. Calder 1 No. 2. 318 ‘tig fae ra aS hae } Hot |Closebrightgray] Green | 7-168 | Supplementary Table, | wees ogasé Se BS Protective Paint or Varnish. State of Covering after 383 days’ exposure. | atta Bos 314 Caoutchouc varnish ......ssseeseeeeeees Varnish not visible ..........sseeseeeeee 314 Best white-lead paint.......+.sessseserees Paint removed in spots .......ssseeeeee a 315 Copal varnish — ........eeeees pach eaeaiaan Varnish not visible ........ sescecccceses 3.15 | Asphaltum varnish ........sseeceeeseees Varnish not visible .........sseseseeeees Pe MalG ool Mastic VAarINSh © cecsocectccscesacsoutvdates Varnish not visible ........scssceceeeee 4 316 Swendtahitaniler.ccnserasnscesasaceessecacas No longer visible ..... depeddescssacesseune i >17 | Three partg;wax + two parts tallow] Gone, or changed into adipocere ...., 317 Sonl-tar, taid (ON HOE .. scssc.cccccsscvese Still lustrous and black ............ oom 3.18 | Turpentine varnish ............s0eeeee Varnish not visible ..........2se0eeeee eas) DLS UPEVINI OM cacy ascascarcesnescoracsveecassen NOt Visible se... cassessmepavecarnesas=-ae | ON THE ACTION OF AIR AND WATER UPON IRON. 293 7. 8. 9. 10. 11. 12. 13. \ Weight of | Total loss Lossof | ‘Sg | a 5 Weight of | Specimen y Loss of | Weight | 238 | Dimensions of | Specimen | after | Corrosion | Weightper| referred | SR | Character of Specimen. in Grains. | 383 days’ in eauere inch toStandard] ‘3 2 Corrosion. exposure. | 383 days, |0f Surface.) “Bar, 3s "5 x 3x -8/5| 24380 | 24062 | 318 | 7-297 | -694 | 0: |Unif, striated. Gray Cast Iron. Skin removed by planing. Fi | 3x3 x 75 | 34114 | 0- | Uniform. | soar | 440 | 677 | 651 | 5xX5x1 | 42238 | 42008 230 3:28 “315 ~5x5x1 | 42293 | 42124 169 2-41 231 ~5x5x1 | 41865 | 41582 283 4-04 ‘388 | 5x5x1 | 42973 | 42790 183 2-61 ‘251 5 x5x1 | 42150 | 41940 | 210 3-00 -289 ” th) ” Bue te 9 ts Order of Condition of Surface of Specimen after 383 days’ exposure. ia aaa roded in pits with plumbago ..........essessecseseose races -8 sound, Hard rust im spots ....sssecsessessesseesesceeces 7 uniform. Coat of hard rust ........ssecececeeceeecscesees 1 Skin uniform. Coat of hard rust ......sssseeecssesssseessenees 2 k coat of tubercular rust......... ss. FEC UNCEE REO ET cna? 9 in spots, with plumbago .........sssscccescesssccesceeeecees 10 sound. Blue rust in spots .........ccscecsessescscereees 4 sound. Superficial rust in spots ......sessescsssscsenees 3 sound. Hard uniform rust .......cccece0 coscecseceences 5 6 sound. Hard uniform rust .........ccccccecsssseescesecs 294 REPoRT—1840. my TABLE Box «. No. 5. containing Specimens of Cast and Wrought Sunk in clear, unpolluted water of the river Liffey, above the tidal limit stream, varying with season from three to six feet in depth. Temperatu on the 4th of August, 1838, at five o’clock r.m. Weighed again, and days. Again sunk at one o'clock v.m., January the 13th, 1840, and now Box «. No. 5. Class No. 1. 1 2. 3. 4. Be gs ra Specific | sax # Hot or External Gravity of | on £5 Commercial Character of Iron. Cold Character of How Cast.| Specimen | Ai Bee 2 Blast. Fracture. es Ws Ag? w 9 | el Nor die Calder ie sveewessswewvecceowss Hot Dark gray | Green | 7:027 } Be Bed Mow dg Caldée -scsgsecssbsvcigbayostac: Hot Mottled Chilled | 7:079 | Box «. No. 5. Class No. 2. <3 Nowi2, Bentwyiiics...ck.cehtvessess0. Hot Mottled Green 7-017 | 4 INORZ.) ECnGwWyil. .ndcorscosssce seen sae Hot Silvery Chilled | 7-129 Box «. No. 5. Class No. 3, 25 | No.2. Cold | Mottled Green | 7-268 | 2 6 No. 2 Cold Silvery Chilled | 7-603 Box «. No. 5. Class No. 4 sifin | Dian BAL Anaptia tA cis dees mane Cold | Dull gray | Green | 7-141! «8 No. 3. Arigna ....csscsseseeesneeenees Cold Silvery Chilled | 7-308 Box «. No. 5. Class No. 5 re) 7 he rec te Old fire-bars,&c.) ...... Silvery crystals} Chilled | 7:624 pO as CAGE Gdevceciesacerancnevies " «10 a SE Noe Peatwyn as } Close dull gray | Green 6978 | POM ce PATIPUA cer succssssagvascaes f x, sll { +3 No.2. Pentwyn... ........ Hot Close dull gray) Green 7 on eh ot BS ON THE ACTION OF AIR AND WATER UPON IRON. 295 1, immersed in the clear Fresh Water of the river Liffey. in the premises of the Royal Military Hospital, Kilmainham, in a running variable, from 32° Fahr. to 68° Fahr. Bottom of fine granite sand. Sunk nded on the 20th of August, 1839, at same hour. Hence immersed for 381 mersed. Specific gravity of water = 1001-39. co tch Cast Iron. 6. 7. | 8. 9. 10. 11. 12, 13. e_e_—X————— |S ———————— | EE Es be: a Weight of ~ 1088 | ross of = = S 3 ; a eens of ei ilo ater. Corrosion bye ay referred ta aa8 eee of in Grains, | 381 days’ in a Surf ch) Standard | ‘3 3 ‘orrosion. exposure. | 381 days, |Q}Surtace.| Bay. Ss" 3 - in, xl 42994 | 42940 54 0-77 074 0: | Uniform. xl 43579 | 43493 86 1:22 “116 0: | Tubercular. Velsh Cast Iron. 5x5xl1 42562 | 42485 7 1:10 +104 0: Uniform. x5~x1 43025 | 42923 102 1:45 139 4:0 | Tubercular. ‘Staffordshire Cast Iron. = 43534 | 43457 77 1:10 "104 0: | Tubercular. | 44174 | 44095 79 1:13 “109 0: | Tubercular. Cast Iron. 5 xX 5x1 43099 | 43024 75 1:07 103 0: | Uniform. IxX5x1 43963 | 438835 128 1:82 175 0: | Tubercular. ’ ' ' 44204 | 44195 79-1 14:13 1 199° | o-'*] Pubercular. ' 43638 | 4358) 57 | 081 | -o78 | 0: | Tubercular. | 43060 42975 85 1:21 ‘116 0: Tubercular. fees 296 REPORT—1840. Box «. No. 5. Class No. 6, ip 2. 3. 4, | | a Sa eS Eis , Hot or External Se a5 Commercial Character of Iron. Cold Character of How Cast.| Specim A ois ® Blast Fracture. no ge + 12 | No.2. Doulais. Common bar ....)..... | Fibrous = Box «. No. 5. Class No. 7. Gray Cast Iro : 4 No. 1. Calder......... nescaes eae . i 213 1 No. 2. Pentwyn 4-3 Scrap Hot |Closebright gray) Green 7 13a Box «. No. 5. Class No. 8. Gray Cast Iron 4 a 4 No. 1. Calder ; 42, ? ae 314 ‘a To ar 3 ae Ss sis Hot |Close bright gray! Green 7-168) No. 1. Cald o. 2. : 215 ie Feanyn ne Gp atgeen age ei } Hot |Close bright gray] Green 7-168 | 1 No. 1. Calder 4 No. 2. 3 h e 16 i Baicas ce rf oan ee Hot |Close bright gray} Green 716 No. 1. Calder No. 2. : ea) fies Ap Pe caiiei vel, 3 ae Saye Hot, |Close bright pray) Gre ie : 4 No.1. Calder No. 2. . : / 2 18 {* p Pentwyn |) L an 3 f fusible, remains long fluid; L Specific Gravity. 7603 7624 7624 7629 7527 7158 6°378 7-015 6-928 6:980 7000 7308 7-116 7017 7168 7°138 7-294 7140 7248 7268 7079 7-134 6-329 7115 7-152 7141 7-001 7183 7:074 7064 7-156 7115 7:097 7:049 7081 7:074 6°838 7124 7164 6°809 7109 7:205 7-152 7-030 7063 7:020 7107 7159 7192 7143 7:076 7:073 7:027 6:978 7-050 How Cast, Chilled Sand Chilled Chilled Sand Sand Sand Sand Sand Sand Sand Chilled Sand Sand Sand Sand Sand Sand Sand Sand Chilled Chilled Chilled Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Sand Observations. Maximum density. Fullof microscopic vesicles. Minimum density porous as No. 7. Minimum solid. REPORT—1840. 304 8-61 ¥9 0- ‘Sqr “gout aaenbs Jad *sq] UI ping udyA aInssor1g *xoid wen SS SSS ea aa a ee ie ee | 9[QeIapIsuod B apUN UOLWOYIpI[og sToy} 0} onp fazis aSiv] Jo ssuyseg ut Apsuap fo aspawour ayy Surmoyg ests 891 LE10- 9FOL-L PFI 1€10- S160-£ 061 9610- 6810-2 96 06T0- 6990-2 GL ITT0- 8990-2 8¥ T¥I0- A1FO-£ Ve 6800- 8GE0-£ 0 “sur *a0ua bk dq| ‘Susur ur Sur “ABI yang [AAPA OB199CS! 4825 yo yided ‘38814 10H “BON ‘o[epady O&FI-Z 89I GFIO: 88E1-L FFI OF1O- SPITZ O06T 9E10- G1OL-Z 96 GEL0- 0680-2 GL €I10- LLLO-L SP 1020- 9£90-L£ 6 £600: 6LF0-£ 0 *surt ‘a0ua *sayour ul Bur ~ragicr ast [4914819 OM10dS|-r5py 30 ydoq ‘ISB[ PICO “LON ‘uoAvuerlg SeOr-£ 891 8é10- £060-£ FFL T€10- 9LL0-L£ 0éT VElo- GF90-£ 96 9€10- 9090-2 GL 1980: SPLO-L 8P G10: €€96-9 VG 6800: 1996-9 0 “sul *goua *sayoul ur Sut ~aagig ysang |AMAPID OMNDAUS -y905 0 dog *9SE[q OFT *[ “ON “WOIT ¥S¥D sopjeg -yydap ut yaoz uaez.tn0J 07 4yaaz OMY WIOITZ Surdava ‘eyo JO proy ‘IX ‘ON @ITavVy; *yuaut “1r0dxqy JO ON 305 oop ee ee eS eee eee ee = E8F0-L rX¢oXg¢ ZFEOL yXoXg 8826-9 yX¢Xe || -g | & |. e600 [120-0 8920-0 e 9080-L exexe ects exX¢xXg 9686-9 eX¢oxe¢] ‘a is 8280-0 0120-0 1410-0 is FOLL-L IX¢xe¢ SOFL-L IxexXg¢ LE90-L IxX¢xg r) 2 1420-0 1¥00-0 9920-0 a CIEL | 0o0X¢Xe POHL | osoxXexe 1980: |0¢0xX¢xe || -q S TF10-0 £100-0 6620-0 a 918L-L | cwoXexeg 6FFL-L | GeO XEXs 0990-2 | Sa0xX¢@xe | cy a “ul ‘ul ‘ur : “url ‘ul ‘Ul ‘UL Ur ‘Ur v7 fa _oo _———$—$— —___| = i si ae “AAVID DyIOadg jo eS Sanravine d “Aqtaery oyroads jo ee Nas icine “Aqiaery oytoadg jo Bt oder Zz a = “SBIG JOE “Z ‘ON ‘aepady ‘SUIT POD “| ‘ON ‘uoavuoLsg “SIG IOH “[ “ON “rapleg 2 2 = ‘SOOURISTANDALD IV]TUIS Japun pue ‘uoly] 4s¥g jo y10s G stvs oy} Mow opel sSuNsug uoIT ut UNG JO esvaiour oj anp Ayavany oytoadg jo aSvaldep 94} SuIMOYG ‘TIX ‘ON 41avy, 306 REPORT—1840. Taste No. XIV. Showing the Chemical and Physical Properties L. 2. 3. 4, 5. 6. € Chemical Composition by Weight) Atomic — % Constitution. per cent. Weight. g Colour, and order of ey = Intensity. 6 — e+ &— e+ WH1 | a - a 2 a 1 Cu + 100:00 + 0 | 31:6 | 8-667 | Tile-red. 2)/10Cu+ Zn 90-704 9:30 | 348°3 | 8-605 | Reddish yellow 1 3; 9Cu+ Zn 89:80+4 10:20 |316°7 | 8-607 | Reddish yellow 2 4} 8Cu+ Zn 8860+ 11-40 | 285-1 | 8-633 | Reddish yellow 3 5 7 Cu + Zn 87:30 + 12°70 | 253-4 | 8-587 | Reddish yellow 4 6} 6Cu+ Zn} 85:40+4 14°60 | 221-9 | 8-591 | Yellowishrel 3 7; 5Cu+ Zn} 83:02+ 16-98 | 190-3 | 8-415 | Yellowishred 2 8} 4Cu+ Zn} 7965+ 20°35 | 158-7 | 8-448 | Yellowish red 1 9} 3Cu+t Zn | 7458+ 25-42 | 127-1 | 8-397 | Pale yellow. 10 2 Cu + Zn 66°18 + 33°82 | 95-5 | 8-299 | Full yellow 1 11 Cu+ Zn | 49:47-+ 50°53 | 63-9 | 8-230 | Full yellow 2 12 Cu+ 22Zn | 382:85-+ 67:15 | 96-2 | 8-283 | Deep yellow. 13} 8Cu+17 Zn | 3152+ 68-48 | 801-9 | 7-721 | Silver-white 1 14} 8Cu+4+ 18 Zn | 3030+ 69-70 | 834-2 | 7-836 | Silver-white 2 15} 8Cu+19 Zn | 29:17+4 70-83 | 866-5 | 8-019 | Silver-gray 3 16 | 8 Cu+ 20 Zn | 28:12-+4 71-88 | 898-8 | 7-603 | Ash-gray 3 17} 8Cu+21 Zn | 27:10+4 72-90 | 931-1 | 8-058 | Silver-gray 2 18 | 8 Cu+ 22 Zn | 2624+ 73:76 | 963-4 | 7-882 | Silver-gray 1 19} 8 Cu+ 23 Zn | 25:39-+ 74:61 | 995-7 | 7-443 | Ash-gray 4 20 Cu+ 32Zn | 2450+ 75:50 | 128-5 | 7-449 | Ash-gray 1 21 Cu+ 4Zn | 1965+ .80:35 | 160°8 | 7-371 | Ash-gray 2 22 Cu+ 5 Zn | 16364 83-64 | 193-1 | 6-605 | Very dark gray. 23 + Zn 0 + 100-00 | 32°3 | 6°895 | Bluish gray. TaB_eE No. XV. Showing the Chemical and Physical Properties 1 Cu + 100-00 + 0 | 31-6 | 8-667 | Tile-red. 2); 10Cu+ Sn | 84:29-+4 15:71 | 374-9 | 8-561 | Reddish yellow 1 3} 9Cu+ Sn} 8281+ 17:19 | 343-3 | 8-462 | Reddish yellow 2 4} 8Cu+ Sn] 81:10+4 18-90 | 311-7 | 8-459 | Yellowish red 2 5| 7Cu+ Sn 7897+ 21-03 | 280-1 | 8-728 | Yellowishred 1 6| 6Cu+ Sn| 7629+ 23-71 | 248-5 | 8-750 | Bluish red 1 7 5 Cu + Sn 72:30 + 27:20 | 216-9 | 8575 | Bluish red 2 8} 4Cu+ Sn} 68214 31:79 | 185-3 | 8-400 | Ash-gray. 9} 3Cu+ Sn | 61694 38°31 | 153-7 | 8-539 | Dark gray. 10}; 2Cu+ Sn |} 51-75-+ 48-25 | 122-1 | 8-416 | Grayish white 1 ll Cu+ Sn |} 84:92+ 65-08 | 90-5 | 8-056 | Whiter still 2 12 Cu + 28Sn | 21:15+4 78-85.| 149-4 | 7-387 | Whiter still 3 13 Cu+ 38n | 15:17+4 84-83 | 208-3 | 7-447 | Whiter still 4 14 Cu+ 4Sn 11°82 4+ 88-18 | 267-2 | 7-472 | Whiter still 5 15 Cu+ 5Sn 9°68 + 90°32 | 326-1 | 7-442 | Whiter still 6 16 + Sn 0 + 100-00 | 58-9 | 7-291 | White 7 Abbreviations used in column 7th to denote character of fracture :— F.F. Fine Fibrous. C.Conchoidal. V.C. Vitreo-Conchoidal. V. Vitreous. are = 1. The numbers in column 6th denote intensity of shade of the specific gravities were determined by the method indicated in Report ‘‘ On The ultimate cohesion was determined on prisms of 0°25 of an inch square, given are those which each prism just sustained for a few seconds before ON THE ACTION OF AIR AND WATER UPON IRON. 307 of the Atomic Alloys of Copper and Zinc of Table No. IX. 7. | g.|9. | 10.| 11.| 12. 13. 14. é 3 A s er 5 ra oe to 5 = Mbps Ue eae ar Characteristic Properties, in See g |g2| 8 [ez lE| é Working, be presence 1 Soi aa Sel be Sea Water. Sl a RC Sa a Tons.) °° 15 ~|9 ° E. 246} 8] 1 | 22 | 15 | Well known. o§ €.C. |1271) 6 | 13 | 21 | 14 Hise F.C. |11-5| 4 | 11 | 20 | 13 Several of these are|| 5 3 F.C. |12°8; 2 | 10 | 19 | 12 | Similar, &c. malleable at high ESzS F.C. |13-2} 9} 918] 11 temperatures. as a F.F. |141| 5 | 8 | 17} 10 223% F.C. {13-7} 11 2|16)| 9 | Bath Metal. a2 sao F.c. 147} 7| 3|15| 8 | Dutch Brass. 9 See F.C. |13:1| 10 | 4 | 14] 7 | Rolled Sheet Brass. 265s F.C. |125| 3| 6| 13] 6 | British Brass, marie C.C. | 9:2) 12 | 5 | 12] 6 | German Brass. a a = C.c. 193} 1] 7] 10} 6 » Brass, Watchmakers’. C. | 2:1; 0| 22) 5| 5 | Very brittle, 126% V.C. | 2:2) 0 | 23] 61! 5 | Very brittle, Too hard to file or| | 94 a C. | 07} 0} 21 | 7 | 5 | Very brittle, turn, lustre nearly; | 3 29 g Vv. | 32) 0|19}| 3] 5 | Brittle, equal to Speculum) | O's 2 Cc. | 09) 0|18| 9] 5 | Brittle, Metal. aS 2 2 C. | 0:8} 0} 20} 8] 5 | Very brittle, J as 25 F.C. | 5:9} 0|15| 1 | 5 | Barely malleable. aE F.c. | 31] 0/16| 2| 4 | Brittle. 2 o's F.C. | 1:9} 0| 14] 41] 83 | White Button Metal. Ss ou | | F.C. | 18) 0/17} 11) 2: Brittle. Sao T.C. |15-2} 13 | 12 | 23! 1 | Brittle, well known. <4" of the Atomic Alloys of Copper and Tin of Table No. X. E. |246) 1 2 | 10 | 16 | Well known. 2 o F.C. 161} 2) 6| 8 | 15 | Gun Metal, &c. eae mG. (15-2: 03 7 5 | 14 | Gun Metal, &c. 5 2 F.C. 17-7; 410) 4 | 13 | Gun Metal and Bronze, aI = g oa V.C. |18°6] 5 | 11) 3 | 12 | Hard Mill Brasses, &c, aa = Vv. |97| 0/12] 2] 11 | Brittle, Agee C. 49; 0] 13 1 | 10 | Brittle, All these Alloys found] | +s Pury C. | 07} 0|14| 6| 9 | Crumbles, occasionally in Bells,| | = 2-3-2 T.C.| 05} 0|16] 7| 8 | Crumbles, with mixtures of Zn| (O.25 2 V.C.| 1:7} 0|15| 9] 7 | Brittle and Pb. we T.C. | 1-4| 0 9} 11 6 | Small Bells, brittle, os C.C. | 39) O}] 8} 12) 5 ” brittle. be fs C.C. | 3:1} 0] 513] 4 | Speculum Metal of Authors, azees eo at|-s|\ 4114 3 nf Files, tough, S" mor, |95| 6| 3/15] 2 a Files, soft and tough. Po me 3 F. | 27| 7{ 1/)164] 1 | Well known. SOE _E. Earthy. The maxima of ductility, malleability, hardness, and fusibility, same colour. The atomic weights are those of the hydrogen scale. The se Action of Air and Water on Iron.” Trans. Brit. Assoc. vol. vii. p. 283. _ without having been hammered or compressed after being cast, The weights _ disruption. : F.C. Fine Crystalline. C.C. Coarse Crystalline. T.C. Tabular Crystalline. pay. REPORT—1840. 308 “IV[NIISAA “19995 "ULI UOd] “UII UOT] "Xe [2019 "Xe ‘30H ‘PIED *PIPD “JOH *PIPD “70H *PI9D “PION ‘POH "0H 40H "0H “PIoO RIOD *PIOD 9 CUPL Ggec.L OLFS-L 6E8S-L OL8¢-£ 6069-£ £6F9-L PIS9-£ eec9-£ 0sg9-£ 1899-2 G6L9-L 8619-4 €869-£ G61L-L S6EL-L 9S¢L-L GOGL-L 6082-2 L16L-L €86L-£ £908-£ F0G8-2 19F8-2 *}S8[Q PIOD 10 JOH | *AqrAwvry oywoadg =f “4829 “PPTL “Pele *paroulUe fy “Peo Polo’ “PIO *PeTlod “PPO *PeTlOd *PeTlou “PITlOe. *paroULMe yy “Palo “Pood *poxroULUe yy PPT *poraUwe Ty “PPTlOd *pasULUIe FT “paso urUre yy “Ped “PeTlou *paiourUle fy *pautloy MOF] a S) O56 HO OGROs Ono Ee ORs aS) CCC ee te Cae ° : 5 ae ca (<2 <<< <=) *oiInjoely *€ tenant enone eteeanene (stejnoq) Ieg Us[9 M popprg sian Suns = Ne SARA S Se SRSSPr es HET UIC)) rg pajppug es tresses 199IG § DODSOY JO UO] IG teesreeseeseessers gros $ aurysdomyg {reg uouULOD ssteseereeeneesesees (SrBmMO(T) TUE USTA\ POYSTUTT : * (steno) reg Ys[9 A perpprd see aeeeeeseceeeeecancers (sammyoang ) reg] 4104S PIOD “= -nauapaBy aseo ‘ atlysdoayg ‘avg woUMLOD sresveeseseess (S1eTMO(T) ALE YS|OM POUSTULT COP OCUL RES CE Mets) aed Ja [log WOULUOD DITYSIOJS9ONOTH ‘UBaqy JO 4satog $ Avg poysrury ss * (8,a00s0yy) o7qissod se prey £ [aa9g 48Vg TORT ew eee eee eee DAITYSPLOYLIS ‘eg 104g poy Henne eee ae eeeeeereneees (Aaqpeag) eg ysysuq qsogq Titteseaeeeseseesees grog £(g Q0080%]) [9939 IBayS treeeeees-ONBTT IOTLOG LOO] MOT ty Mase rok es SNBEASPA EP AID SCTE uol] de.tog pojj033e, sreseeeseeeeees (Korpeig) pasoduay, ‘jae7g Suradg oo UBysuIUG $uo1y poqreureg Aenean eee eeeeeeeneeee (s, 90080} ) POEL 19018 4seg FO eee enna eeeeeeeeeee (AoTpeag) yo (9918 Suudg : *+ (RiomlauUR(y) WOT] YSIpaMg Fn vn = Bere temas | 4S Joystiq *Io}OVIVYD [PIOAOUIMIOD 6 *UINUTULAY 0} TUNWIXRY WOIZ Jopso ul ‘[ae4g pu UOT YYSNOIAA Jo sarytAvay oygroadg ‘TAX STV, SAMs snd *JaqUINN ‘I 309 Report on some Observations on Subterranean Temperature. By Roserr Were Fox, Esq. Havine already given, through the Philosophical Magazine*, a summary of tne observations on subterranean temperature which I had previously published from time to time, I must, in complying with the unexpected invitation of the British Asso- ciation, necessarily include in the present Report many of the details contained in that memoir. Early in the year 1815, my friend Joel Lean stated to me his conviction, that the high temperature observed in our mines existed in the earth itself, increasing with the depth; and shortly afterwards his brother Thomas Lean, at our joint request, kindly made many experiments in Huel Abraham Copper Mine, of which he was the manager, in order to test the correctness of this view. The results obtained by him tended to confirm it very unequivocally; and so did another series, made in the same year at my request, in Dolcoath Mine, by John Rule, jun., one of the superintendents. Many other individuals have since obligingly carried on similar ob- servations for me in different mines, all showing that the sub- terranean temperature increases, in some proportion to the depth from the surface. The ratio of its increase at different depths, and the causes which exercise a greater or less influ- ence upon it, have, however, hitherto been undecided. I have elsewhere endeavoured to show, that the rate of in- crease is not so considerable at deeper excavations as at those which are shallower ; and the subjoined Tables will, I think, exhibit this point in a satisfactory manner, as far, at least, as the results obtained in some of the mines of Cornwall and Devonshire, which I have published from time to time, may be considered an authority. * Phil. Mag. 1837, vol. ii. p. 520. Tabe I. Taste I.—Showing the Results of Observations on Subterranean | ; the Ratio of its Increase at different Depths. the deepest levels or accessible parts of the respective mines. ao mo b ann — | Number. | Date of Observation. 1822 1827 1827 1822 1822 1820 1820 1820 1822 1820 1830 1824 1824 1824 1827 1827 1827 1822 1819 1822 1822 1822 1822 1$20 1820 1820 1827 1827 1820 C. stands for Copper Mine. = re T. ditto Tin _ ditto. Mines and Localities. G. for Granite. K. for Killas. South Huel Towan, St. Agnes, C.K. in cistern or reservoir at the bottom Huel Wellington, near Camborne, C.K. small stream from Western end of deepest level...... Ditto ditto ditto Eastern ditto ......... East Liscombe, near Tavistock, C.K. in deepest CISCTED) sonsnadascnacseccsscececcusscsccsvvavecesvoseues Huel Unity- Wood, Gwennap, Tin, K. in ditto. eoes saeecere ae ee ereeseesees *Huel Unity, Gwennap, T. and C.K. ........ cantase Ting-Tang, ditto C.K.,, in the lode ......... Huel Gorland, ditto CAS GRRECRACScoc ee seacoanone Means of depths and temperatures... Beer- Alston, Beer-Ferris, Devon, Lead and Sil- ver K., in deepest cistern iP Huel Squire, Gwennap, C.K., in deepest cistern.. Huel Rose, Newlyn, Lead, K., deepest level Chasewater, Chasewater, Tr. K., in E. end of deepest level ....sscescccesccesecrsececccerscccncees Ditto ditto, W. end of deepest level ....«: Huel Trumpet, Wendron, T.G., in deepest level... *Huel Jewel, Gwennap, C. and T.G., 40 fathoms to the E. of shaft, and 4 feet from end of level Ditto ditto, 18 ditto, W. ditto, and 4 feet ditto Huel Vor, near Helston, T.K. in ge level, 4 fathoms from shaft *Consolidated Mines, Gwennap, C.K. in n lode, 16 fathoms E. of Job’s shaft J2..0...0..s} a | Zz 4 S a i = a 4 o 2] [ & we. 2 wn eal my = a (=) ey bales NR Sel les PRC cles eS aces a T |8t ASM} MSM] ASA |] MSM} MSM MSM | MSM AASAA | AASAA| AA M |MSM!/MSM/MSAA] MS t | ¢ Pe | Ah Bol Bo) OR testes ie oe cal ee a lea ae MS | MS MSS | ASS | MSS | MSS} MS | MS | AS MSA] ASM | MASA eee wee REPORT—1840. SS ae —— ee ae " Poy s§ - plzeieltelel cl elt jee lull eich lt ey ey) ct [tel & “ANN eee z z z z cal one +e eee aoe wee eee oe vee ae wee eee ane z 4 “MN tr tt | | ¥ | 9 [te [fer] orite ft ft pa bp pepe a tt “ANNAN er| ot Spr] tar |tet| for] ot|est|| ot|fer} et] 2 | ¥ |te jte | vy | @ je [te | 8 “AN te [fe [& [e [oc le [te [ft fet |e [ts | |e | a] ge tte | 9 | 6] 8 | "ANS" AA + |r ite [fe] 2|8| 8 jt | o | [fo [fo [ts [tr | 4 jf8 | > [te | & |e “ANS to zi ole fale itr io tie ie it jb fe fw |e) 2 pte oh) e “M'S'S eee aes oo aoe nee see eee & & I z - oo ae see eee . ase - ‘gS eee . aoe ane oo see oo nee aoe wee see nal ane eee eee ase - .. - eee “TSS Plate pallickeraleratyaicet cafas Harb aeg Mie | coed diene Tooke mee | ne Peedi ve Sate —_ rise elt letede ted dette fe pe pe le pe) to +, CNT wg ltzisieltelzie6lsio9|/o9le/e]s| site} e|e| 8 |t to aN rhe BPE Re ar Be ew ee ee a er es ae aL a) 8 ‘O'N'N wee ane eee eee eee eee wee aes & & & & & sal I eT - wee see wee "N erage et et el G.| CSR ee OE) 6 fs fe] 8) oy ery By Tt 326 “9E8T AequIs.0(T "T FIQey, Jo prysqy—T] JTAV,L 327 ON THE SELF-REGISTERING ANEMOMETER. ‘TA [2L pur “Ay vig vag ft “AT 19% L pur TIT avg ag y "1 ‘Sy “TL arejg aag 4 eva (FU | 8) tre) re] veloe | 6a) foe | fer | fee |41F| Feel] te] 22} eal tre|er|gorlge lez lee lee | al ex { seen eet eee iz ‘4 BT z Sy a 4 I see tee ous eae ane eee wee aoe see * wt “< 1 1 oe |g & t I is eae ia ga sta (heen ily aan iieitgtanh bags tee see lees “AONT ° eee eee wee t wae eee eee - . eae eee - eee eee wee ~O 9 eee eee eee Sal ST I e I & eee eae . - . see . eee jeer dag eet & pest g By g g ve [ice 1B Teele & sai ietat’ ul? sralerl| eae goalie % see | see | vee eS] oa] tem Ul see [oes eee o | wer fark | nek [Ehge |aee ieee | ane ony ogi se eee wee eee & & & & see aes . ene . eee eee wae ere lees Aine Se & soe | & wee I % ay | hee iene) (| eeape 1 /é & Sa a aR ie CR 968% | OL] €1| FI #96} 83] f1Z|/eo | 13|fstjoe jit |tz | + |4¢ [#8 | 9 | 6 |fttk Psa pa 6 /fIT/EL EL | ¢ | o [fo |e |e [tt fo] 91] ¢ | el g fe sem 1006 | 4 | 8 | 46 1) @1; 4 | 4 | 6 |t6 | IL] t9 | fF |e | | #81 T | ¢ [49 fo mdy tLOlt |¥@ |f9 | Ez 8 | Ol] 6 er | m lta) lee te} ot] el ltt | ole le Pd 2 1 of & p e e |§1 I Ral ease ae ce a t fe ‘qeq tog EL | fe | fF li de lft elf ol gl foe] eee te seed pee sed ee, ce gee LZ 4 see sae . see & g & & & ca I By ee one one seo fees “Oat I | IL | OL €/@)} 1] a} m/or;é;s)/4)/9)}¢]/rie| eit “s[ejO], *Ajaaryo9T[09 uayey sojrenb yora pue yuo Yowa Jo sao10j [e407 ayy pure “ivak ey} Jo saaqjaenb pure syyuow 944 surysmmsurysip ‘oF pure ‘“6E-8E-LEsT savoX ayy Joy sanoy anoj-Ayuaay 94} SuLINp puIM yora Jo sooI0y oy} Jo wns ay} Supmoyg—" [IT A714, vi een rr 1840. REPORT ‘TA A1deL pur ‘ay aeq eg fF “AT P98L Pue “TT Id 9S x ‘T Sy ‘11 awd vag + 409 | ot|fou|$et| tra] et] Gt| 92) ge] Fel ttF| oF] FHI TOF] OF) 98) toa] tee] OF | ter | ToL] et] ToL} BT] te ead feat |f1 |$t | & |9 [tt [ft [fe | @ | ¢ jis | 9 | 2 te lt jfe | et Yo Cee Nee es Ie a 2 ty let 181 |e |8o [Rr (FL | oe | Ft te |te | y |v ty yet |e | er (prea lnk aba sail je ibe ak ist ; pacers I Lire i a Hil a pee ie a: Lat : aes 0 E Fh 1 sie ena a ee sas nati : $a Ang £9 . oe . 8 sae |* . see . I & I & I & & g see aune Scort | Ete \ Sst) at| Ser) st|t91| fos} sal| fea) Fa] eal F47|| Fos| For] Go) F8L)T41] tet | TFL} ts | ts |t9 | TOL} 6 |x egg | g |ftt| 6 | et] 11] ec) Fet} 13 fst] fsr| irr] Zt || Sl] Sl] PL|FSL| TOL/ TIL] 1) 9 | 9 “SETA 9 Po AG Ci i lf |to]e) @ [to lt |f | tit | [ft | 7 lO S| el el SA a a etl 8 A) 0 bf Be ae | eee Zl z I wee sad a z I % 4 see wae eee see wee eee see wee aoe aoe wee see see see . Bee ye - | en-| ote foe Pip) yee | ET FOL FOL PPE 6 OTT Ee om: joe. tee | | 12 pall eta ic lta J ee fl - Fee N ¢ l a F W pee vo feng FL cee So H I I ey fy e 4 ‘| Dae. By . rae xe, . [ : g aa ke FY e 0 e judy 1 gal ae Wi Wea i eh ol 9 el al aoc a Jc SU your] zoe | ¢ |% | ¢ te [#8 | 2 | 2 [fs | 2 to | 2 ley ity |forl far] 8 | 11] orl ter] F1/ ter} te | t6 | ts We ee oe Me ee ee bt foe ite (Fe 6 [fo [eo | 8. | 8 Ree de | 8. EL “ae tog [Gc |te |to | + | ¢ | | 1 le lte [fe [te | c tt |fe | & | e | © |te [te | 9 [to | 2 [te | 2 fo cove Pee eel eee ee. hoe ie.) ee ee he | elk de [ee (4 bo Pe | 8 te eee Coe eae PAN By) tea (al at ek) li i at jo a 7 i SY i TY ty Sa

# |#¢ |4¢ | 1 ol Ve | water ales I eS: ee z I aT 21 a 41 41 I ey tI I I I Toe es fee I & ST #1 I & A ea | OPCs Sete | lecicwey Iudy t6 & z& & I az z & one I & & qoue yay tL49F | ot} o1/ Ete t6L} 18/¢ea]£2e| oe] zz 10s] €¢]fo0e|| tel ez 96| 92) +1 ¥698 | for/%6 | _et| Set] et] ger] 91 TL) FOL) £0] f9t| 6r|/fos/for| erlez | z |g qd sis tg |#9 |?g | ¢ | 9 OL/tI1} er/ for] Fer] Fg IL || 701 /#2r} et| fer] 9 me éI} It }0l} 6] 8] z]9 S/F} ee} otra a or; 6| 8 ‘ol J) H i ane Remte eeseeynemeeeiseeer cee eee a La Ea | REPORT—1840. 332 tosh |Z lk 1@ | £1 \t0¢ | Zz | oF T0Z1 te TIL \t@ | SI pe fe 6 |¢ ol g Pe OR ce $01 “ 2 i 7901 Kay ry |¢ io SP wee eee I ay 70S Eg rir ite 418 8 y |e | OL ish g € |1. if9 tL& g Del te ae GF F It [for |for pot i ig ls it6 E Ce LI : hee Come Ll om 9 leita *S[PIOT, ‘Wd G | FE | LT =a rat ‘Ob-6-8-LE81—(‘penurjuod) *]]] xTavy, 333 ON THE SELF-REGISTERING ANEMOMETER, “s[eq0J, e1z| ealSee| ec|t9a| Fa|$21\ter| €2| fer] tre) ise |t4e| Le) f9a|t1s| se) tor|tZ |t1r|t6 | ts | t6 | ot ot | 6 | o |e [49 [$2 | 9 | 9 | 1t| fot] on] mito |tit}to | @¢ | 1. |fe pT pte} tt] 1 | it ie @ (fe |i] le lee] ele [fer] > | yi @ te |e fo] bt | rte) el) et lee ze \tc ltr [ty | ¢ | 9 | @ [to | © |te |e |e | et it jer | Spay as | |r [$e |e |tt [ft |fe | @ |e | w]e lt arjijor|j6}/s{z}9}¢]|r |e] ej uy er] myo; é)s, 4) 9) es] r7] &) @ I ‘I'd ‘AV “1201 1840. REPORT 334 Seerr| or (fze lege \tzr Eee [See | og Seo | 19 | 99 | 19 | £e |f69 |$09 [fe9 ero |Ece | 62 foe | oF | oF | ge [foe | ze [4 OL Peek |S Seen Stein me cet | a) el Te a wa | il Ma (cece (ea al snare cs | rt Pt sade ttm 4) at Poa uay Sese |g | F | ar 11 \Ser | 6L [St | st itgz |t¥a | 20 |t9t |t0% | €% tee \t6t [e9t 9 | OL \f9r | et \t9T | ot | eT cre | z \fe [6 | 2 | 01} St} or $e | Zt leat Hor ite | St jfou \f1t \tor 6 |f¢ | £ | et | IL | ot \tor | 11 “AON oT ot ee Re ee ee Pee eee ie oP Re eo erate ory Te Hy lo ae) me ee re Ne ee ee OO Behe he re he Re Re |e Pe aa fecz |\tz | or eZ [tS | OL | GL FL | OL | FL IEFL [Eau [EIT || 02 | SI | 02 | of fe jt |9 |S | 9 Kr ¢ e9 ite |fe |te fe it Jt elit ip ie te ote iF tS Ee PBF) ie Hee Leen hie ‘sny 79 ace ci fcc OU bg “ame UT el fp ¢ TR pce ecm a Gb Je 09 fy] OR am a 2 i (mi 8 fe Aine fis i¢ if9 |&§ |@ |e He He |e ito 9 He |9 it 1¢ FF i aa aca a | a Se gt me a ie LOC ofl |e |jge |e lt |e ie ft y |r He |itrie6é |8 |¢ |* Jo I ito |} 24 16 He He ite itt ee ee te aa eal ae ee eee ee Tee SED" 8 San Tike oe. 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Mees Ae I eee $% hid % az c Se 32 I & 4 & ¥ z I see see eee eee eee eee eee see wee FEAR ClIsCey ed Pavee Nene Pe Nya et) TOC) hoa Aa i MAE yn Ph et eC ek et Lk ns a Yi Wa TA ede -scn| i = we Bo 353 Report on the Fauna of Ireland: Div. Vertebrata. Drawn up, at the request of the British Association, by Witu1aM Tuompson, Esq., ( Vice-Pres. Nat. Hist. Society of Bel- fast, ) one of the Committee appointed for that purpose. PART I. Ir has been remarked to me, and by a distinguished naturalist, that the zoology of Ireland can hardly be worth attention, from the similarity it must bear to that of Great Britain, already so wellknown. But, properly considered, the zoology of an island which, in the eastern hemisphere, constitutes the most western land within the fifty-first and fifty-fifth degrees of north lati- tude, cannot but be highly interesting, especially in connexion with that most attractive subject, the geographical distribu- tion of animals. In Ireland, we find within the degrees of lati- tude just mentioned the extreme western limits to which all our species range that are peculiar to the eastern hemisphere. In Zoology, however,—that is, in Vertebratal zoology, for of it only the present communication treats,—we do not (as some writers, without reflecting on the very different circumstances which in- fluence the distribution of animal and vegetable life, have an- ticipated,) find the same interesting results as in Botany. The West and South of the island do not present us with any of the Vertebrata of Portugal, the western Pyrenees, or the South of Europe, which are not found elsewhere in the British Islands. The Erica mediterranea, Menziesia polifolia, Arbutus Unedo, &c., have no animal representatives*. Throughout this Report it has been considered desirable to contrast the zoology of Ireland with that of Great Britain,—to present, in fact, a comparative list of the Vertebrata of the two islands. It must, however, be borne in mind, that all species found from the Channel Islands in the south, to the Shetland Islands in the north, are included in the British Fauna, and that within the degrees of latitude over which it extends, Ire- land occupies but one third. © Ireland is comprised within four degrees, whilst the Shetland Islands range nearly six de- grees further to the north, and more than two degrees to the south the Channel Islands are situated. The Fauna of Great Britain also extends over ten degrees of longitude, whilst that of Ireland is limited to half the number. The physical geography of Ireland must, like that of every * What may be the distribution of Lepus hibernicus and Mus hibernicus is yet indeed a problem. 1840. 2A 354 REPORT—1840. other country, have a primary influence on the number of indivi- duals of the species which are found there either permanently or as periodical visitants. At the same time, its natural features do not differ so much from those of Great Britain as altogether to preclude the presence of more than one, or perhaps two, verte- brate animals, which have a place in the British and not in the Irish Fauna. These are the Ptarmigan (Tetrao Lagopus) and Alpine Hare. For the abode of the former, it does not afford a continuity of mountains of sufficient altitude and of such a nature as this bird chiefly inhabits. The haunts of the Alpine Hare (Lepus variabilis) are pretty similar to those of the Ptarmigan, but often at a much lower elevation. The influence of climate is now to be considered ; and under this head the species just mentioned might perhaps with pro- priety have been included. The difference between the tempe- rature of Ireland and Great Britain cannot with any degree of certainty be said to attract to, or repel from, our island, any species of the British Vertebrata. Our mild winters in par- ticular have otherwise great influence. The Stoat (Mustela erminea), for instance, very rarely in winter changes the co- lour of its summer fur to the warmer and more attractive garb of the Ermine, in which it is so much better known. Even in the north of the island, some species considered as birds of pas- sage in England, except in the extreme south, are induced to become residents, as is the case with the Grey Wagtail (Mota- cilla Boarula), and to a very great extent with the Quail (Perdix Coturnix). Of the Grallatores, some few species re- main throughout the winter in the North of Ireland, although only to the South of England are they known at this season. But, above all, the mildness of our winters is such, that some of the soft-billed birds, which are generally able to procure an abundance of food, are more disposed than in the neighbouring island to song, and accordingly at this period of the year de- light us with much more of their music. The humidity of our climate would seem to attract to fa- vourite localities more Woodcocks (Scolopax Rusticola) than are found in any part of Great Britain, and, together with the great extent of bog throughout the island, brings hither to winter many more of the Jack Snipe (Scolopax Gallinula), and of the common Snipe (Scolopax Gallinago). The two last, above all other birds, exceed in number those found in England and Scotland. The indigenous Starlings and Snipes are as nothing compared with the numbers that pour into the island during autumn from their breeding-haunts in higher latitudes. a ———————— ON THE FAUNA OF IRELAND. 355 Our moist and rich meadows draw hither in spring more Land-Rails (Crex pratensis) than are generally to be found in the meadows of England and Scotland ; but in the case of this bird, the far-western position of Ireland should perhaps be considered, as in Portugal the species is about equally abundant. Mammalia.—It is so extremely difficult to procure the greater number of the animals of this class, that some, especially of the smaller species, are doubtless yet to be discovered; as known at present, they appear to fall short of those of Great Britain in an extraordinary degree. In the Cheiroptera, or Bats, we seem to be remarkably deficient, but time must add more species to our list. In the genus Mus there is a species —the M. hibernicus—as yet unknown elsewhere. The Squirrel (Sciurus vulgaris) and Dermouse (Myoxus avellanarius) are desiderata: of the genus Arvicola I have not seen an Irish example. In Lepus, the place of L. timidus and L. varia- bilis is supplied by L. hibernicus, as yet known only to Ireland. In Mustela, the Polecat (M. Putorius) is unknown to me; and if M. vulgaris be indigenous, it is much more rare than M. erminea, which prevails from north to south. Of Felis Catus, as an Irish animal, positive information is yet wanted. The Talpa europea we certainly have not, though in Great Britain mole-hills may be observed close to the sea-side at some of the nearest points of land to Ireland, as at Holyhead in Wales, and Portpatrick in Scotland. The Soreces at present known are but two in number. Ireland possesses as many Bérds as from her geographical position might be anticipated. The species which appear in the catalogue of Great Britain and not in that of Ireland, are chiefly occasional visitants, many of which have no doubt ex- tended their flight hither, although they have not come under the cognizance of the naturalist. This refers chiefly to strag- -glers or single birds; the species which come in flights to Great Britain generally extend their migration to Ireland also. In the class Reptilia nothing particular need be remarked, except the well-known fact of the absence of Ophidian Rep- _ tiles from the island. In Amphibia we have not the Toad (Bufo vulgaris) ; the Frog (Rana temporaria) is stated to have been introduced ; the Natterjack (Bufo Calamita) is believed to be truly indi- genous to Kerry. The coast of Ireland offers nothing very remarkable in Fishes. 'The families having a place in the British catalogue and in which the Irish is particularly deficient, are Percide, 2a2 356 REPORT—1840. Sparide,and Tenioidee. In fresh-water fishes there is, com- pared with England, a remarkable poverty in the species of Cyprinide ; yet, leaving out of the question geological in- fluences, there are in certain portions of Ireland lakes and rivers apparently well suited to this family. Scotland too is very deficient in the Cyprinide. In the following catalogue of the vertebrate animals of Ire- land about 420 species are included; namely, of Mammalia, 302; Aves, 2302; Reptilia, 2; Amphibia, 4; Pisces, 150?; omitting in each class all extinct and naturalized species. To take a general review of the Irish Vertebrata, as known at present—and every year several species are added to the cata- logue—and of the causes of the absence of species found in Great Britain, it is believed that the physical geography and climate of the island will account for that of only one or two. The want of old timber over the country might be considered an obstacle to the presence of certain Mammalia and Birds, as the Cheiroptera, or Bats, a large proportion of the British species of which inhabit old trees ; the Squirrel, &c. In Birds, the Picide, or Woodpeckers, their congeners, and some others. The absence of all species which would not be affected by any of the above circumstances, and which we really have not, seems to me to be attributable to geographical distribution alone; thus, as the shores of continental Europe on the same parallels of latitude as Great Britain are the western boundary to many vertebrate animals unknown to that island, so again are the shores of the latter the extreme western boundary to many species unknown to Ireland *. Note 1.—The North-east of Ireland and South-west of Scotland, although divided by so narrow a channel, are zoolo- gically very different. ‘The species unknown to me as Irish, but of which I have seen examples from the opposite coast, are, the Polecat (Mustela Putorius), Mole (Talpa europea), Ciliated Shrew (Sorex ciliatus), the three species of Campa- gnol (Arvicola amphibia, A. agrestis, and A. riparia), and the common Hare (Lepzus timidus)—the Black Grouse (Tetrao Tetrix)—the Blind-worm (Anguis fragilis), Adder or Viper (Pelius Berus), and Toad (Bufo vulgaris). In the genera to which the animals just mentioned belong, Ireland is known to possess but one species which is not found in Scotland, the Lepus hibernicus, and of the terrestrial Mam- malia generally, but one other, Mus hibernicus: of the com- * Several species of British Birds are either not found in the West of En- gland, or become rare towards that quarter; as the Nightingale, Nuthatch, Wryneck, Kentish Plover, Stork, &c. ON THE FAUNA OF IRELAND. 357 mon Shrew-mouse of Ireland (Sorex rusticus), indeed, I have not seen any specimens from Scotland, but there can be little doubt that the animal is found there. Note 2.—The situation of the Isle of Man—midway between Great Britain and Ireland—suggests the inquiry whether cer- tain species not found in the latter island prevail there. On this subject Mr. E. Forbes informs me that the Mole, Squirrel, Dormouse, and Roe-deer are not indigenous to the Isle of Man; neither is the Toad, nor any species of Ophidian Rep- tile. A skin of the Hare of the island sent me by Mr. Forbes is that of Z. timidus, the species found in Great Britain, and represented by L. Azbernicus in Ireland*. * It may be desirable, with reference to the above remarks, to allude briefly to such species as, found in Great Britain and not in Ireland, prevail further to the west. In Mammalia, five of the British and non-Irish species are found in the western hemisphere. ‘They all belong to the division Mamm. Aquatica, and are only occasional visitants! to the shores of Great Britain. The species are Culocephalus (Phoca) greenlandicus, Trichecus rosmarus, Delphinus Tursio, Delphinapterus (Beluga) leucas, Monodon Monoceros. In Aves, sixteen British and non-Irish species prevail in the western hemi- sphere. Of these, the Ptarmigan (Lagopus mutus) only can with certainty be termed indigenous to Great Britain, and for its absence from Ireland reasons have already been assigned. Linaria canescens seems not yet to be properly established as an indigenous British bird. Two species, Procellaria glacialis and Lobipes hyperboreus, are periodical visitants, the former to St. Kilda only, the latter to the northern Scottish islands. The remaining twelve are occa- sional and very rare visitants to Great Britain or the neighbouring seas. They are Nauclerus (Elanus) furcatus, Surnia funerea, Plectrophanes Lappo- nica, Ectopistes (Columba) migratoria, Macroramphus griseus, Tringa rufes- cens, Tringa pectoralis, Oidemia perspicillata, Clangula histrionica, Merganser -cucullatus, Larus atricilla, and Thalassidroma Wilsoni. In Reptilia, two species which have a place in the British and not in the . Irish catalogue, belong to the western hemisphere : these are Chelonia imbricata and Sphargis coriacea. In Amphibia, none of the species under consideration occur in the west. In Pisces, several British and non-Irish species appear in the North Ameri- -ean list, but they are all known only as rare and occasional visitants to the shores of Great Britain: They are Zrichiurus lepturus, Sebastes norvegicus, Naucrates Ductor, Exoceius exiliens, Engraulis encrasicholus ?, Echeneis Re- mora, Murena vulgaris ?, Zygena malleus, Scopelus Humboldtii, and Xiphias gladius. The Mammalia, Reptilia, and Pisces of the West are taken (with the excep- tion of Sphargis coriacea) from Dr. Richardson’s “ Report on North American Zoology,’’ (Report Brit. Assoc., vol. v.), and Dr. H. Storer’s “ Report on the Fishes &c. of Massachusetts ;” Aves, from the Prince of Musignano’s “ Com- parative Catalogue of the Birds of Europe and North America.” 1 Throughout this Report, the term indigenous is applied to species perma- nently resident; periodical visitant, to those which come annually; occasionaé -visitant, to those met with at uncertain intervals. 358 REPORT—1S4G, PART II. Div. VERTEBRATA. Crass MAMMALIA.—Secr. I. MAMM. TERRESTRIA- Order 1.—CHEIROPTERA- Fam. Vespertilionide. {Throughout the comparative catalogue, the mark 0 denotes absence, as the mark + does presence. Thus Vesp. Noctula is unknown in Ireland; V., Pipistrellus is a British as well as an Irish species.] Ireland. Great Britain. 0 Vespertilio Noctula, Schreb. 0 = Leisleri, Kuhl. ae discolor, Natt. Vespertilio Pipistrellus, Geoff. + 0 2 pygmezus, Leach. 0 a serotinus, Gmel. 8 P murinus, Z. 0 a Bechsteinii, Zeés/. Oo “t Nattereri, Kuhl. 0 4 emarginatus, Geoff. F5 Daubentonii, Leis/. 0 ms mystacinus, Leisé. + zedilis, Jenyns. 0 Plecotus auritus, Geoff. Plecotus brevimanus, Jenyns, Barbastellus Daubentonii, Bell. Rhinolophus Ferrum-equinum, Leach. Ae hipposideros, Leach. Of the Vespertilionide, of which 18 species are now enume- rated as British, all that can be announced as Irish are the Vesp. Pipistrellus, V. Daubentontt and Plecotus auritus: the first and last are common from north to south of the island: of the V, Daubentonii*, one individual was obtained by the Ordnance collectors in the county of Londonderry. That other species remain to be discovered, there is little doubt. Of the British Bats, 4 species have each been found, but in one locality ; and of 4 other species but a single individual has been procured. oooo Order 2.— BEsTIz£. (Ferz Insectivorz.) Fam. Hrinaceide. Treland. Great Britain. Erinacens europeus, L. =. Common throughout the island. * The species determined by Mr. Jenyns. ee a —” ON THE FAUNA OF IRELAND. 359 Fam. Talpide. Treland. Great Britain. 0 Talpa europea, L. Fam. Soricide. Ireland. Great Britain. Sorex rusticus, Jenyns. + » tetragonurus, Herm. 0 Sorex fodiens, Gmel. 0 » Ciliatus, Sower. 0 » castaneus, Jenyns. S. rusticus is the common Shrew of Ireland from north to south; of S. tetragonurus I have seen but one native speci- men, which was procured by the Ordnance Survey near the Giant’s Causeway. Order 3.—FrErz#. Fam. Urside*. Ireland. Great Britain. Meles Taxus, Flem. + In suitable localities throughout the island. Fam. Felide. Ireland. Great Britain. Lutra vulgaris, Eraleb. (?) + + Mustela vulgaris, Z. (?) + » erminea, LZ. + 0 Mustela Putorius, L. Martes foina, Bell. + AA Abietum, Ray. + 0 Felis Catus, L. Vulpes vulgaris, Briss. + The Irish Otter, named provisionally Lutra Roensis by Mr. Ogilby, is not now considered by that gentleman distinct from L. vulgaris; it is not uncommon. Of the Mustele, M. Puto- rius is unknown to me as Irish; and of M. vulgaris, which is noticed as common by Templeton and others, I have not seen a native specimen: M. ermineais common from north to south, and passes under the name of ‘ Weasel’. Martes Abietum is found throughout the island; of M. foina, but one native example (killed in the county of Antrim) is known to me. The * Ursus Arctos, L. I am not aware of any written evidence tending to show that the Bear was ever indigenous to Ireland; but a tradition exists of its having been so, and it is associated with the Wolf as a native animal in the stories handed down through several generations to the present time. + The note of interrogation within brackets (?) marks species doubtfully Irish. a 360 REPORT—1840. difference of colour attributed to these animals appears to me of no value as a specific character, as in course of shedding their fur they become particoloured, the breast as well as the body presenting at the same time the colours of the Beech and the Pine Marten*. Certain data for including Felis Catus in the Irish catalogue are wanting: it is said to frequent the wild district of Erris (co. Mayo). Vulpes vulgaris is commont. Order 4.—GLIREs. Fam. Castoride. Ireland, Great Britain. 0 Arvicola amphibius, Desm. 0 » arvalis, Gm. (agrestis, Brit. au- thors). 0 » rubidus, Baill. (riparia, Yarrell). Of the genus Arvicola, there is not any species known to me as indigenous to Ireland. Fam. Muride. Ireland. Great Britain. 0 Sciurus vulgaris, L. 0 Myoxus avellanarius, Desm. 0 Mus minutus, Pall. (messorius, Shaw.) Mus sylvaticus, L. » Musculus, Z. ao » Rattus, L. (2) +- », hibernicus, Zhomps. 0 », decumanus, Pall. + Sciurus vulgaris is not now a truly native animal}; it was in- troduced a few years since to the county of Wicklow, where it is said to be fast increasing in numbers. Rutty, in his Natu- ral History of the County of Dublin, (1772,) vol. i. p. 291, re- marks that it is “‘said to have been found in the wood in * When the above was in the press, Mr. Eyton published in the Annals of Nat. Hist. (Dec. 1840, p. 290) some valuable remarks on the British Martens, tending to prove that they are in reality but one species. He states that the young animal has the yellow breast attributed to the Pine Marten, and the adult, the white breast of the common “species.” I had also long since remarked that the yellow colour of the breast gave place to white. This view would satisfac- torily explain why the yellow-breasted one—MM. Abietum—should appear to be the more common with us, as by far the greater proportion of animals that fall victims to man are those which have not arrived at full maturity. + Canis Lupus, L. Smith, in his History of Kerry (p. 173), states that Wolves were not entirely extirpated in Ireland until 1710. That noble race of domestic animals, the Irish Wolf Dog, so successfully used in their pursuit, has, since no longer required, been neglected, and must now, I fear, be called extinct. { There is a tradition that the Squirrel was common in Ireland before the destruction of the native woods. ON THE FAUNA OF IRELAND. 361 Lutterel’s Town.” In the same work it is observed in vol. i. p- 277, that ‘a vulgar error has prevailed, mentioned at Jon- ston’s Historia Animalium, that the Dormouse was not found in Ireland,” &c.; a sort of description of the animal follows, but by no means proving it to be a Myoxus. Mus minutus cannot be announced as Irish; but a native animal was once described to me which would agree with it; M. sylvaticus and M. Musculus are both too common over the island. The ani- mal provisionally called Mus hibernicus* is now so rare that I have been able to obtain for examination but one specimen, which is insufficient to establish it properly as a distinct spe- cies; M. Rattus, though very rare, is stated to occur occa- sionally in various parts of the island. . In his Natural History-of Dublin, Rutty states that the Mus decumanus ‘first began to infest these parts about the year 1722.” (vol. i. 281.) It has long since overspread the island. Fam. Leporide. Ireland. Great Britain. 0 Lepus timidus, Z. 0 » variabilis, Pall. Lepus hibernicus, Bell. 0 Cuniculus, LZ. + The only species of Hare known as Irish is the L. hiber- _nicus, which is common throughout the island, as is likewise LL. Cuniculus+. = Order 5.—Percoraf. e 4 , Fam. Cervide §. Mi Ireland. Great Britain. Cervus Elaphus, L. . 0 Cervus Capreolus, Z. _ * Proceedings Zool. Soc. London, 1837, p. 52. z - + This animal passes under the names of burrow and bush Rabbit in the North of Ireland. ‘These are distinguished from each other accordingly as they bur- Yow in the ground in the ordinary manner, or live in “forms” like the Hare among bushes or underwood. This departure from their natural habit is, I con- ' teive, only resorted to where the soil is unsuited to burrowing. In the Annals of Nat. Hist. vol. v. p. 362, a notice will be found on the subject of Hares bur- rowing in an exposed situation on the western coast of Ireland, to which they _ were introduced, and where they could not otherwise find shelter. __ ¢ Bos Taurus, L. The remains of a race of Oxen, believed to be peculiar to oo are found in our bogs. The distinguishing characters are, “the con- “Vexity of the upper part of the forehead, its great proportional length, and the “shortness and downward direction of thehorns.” See an abstract of a paper by Mr. R. Ball, “On the Remains of Oxen found in the Bogs of Ireland,”’ in the : Proceedings of the Royal Irish Academy, January 28, 1839. § Cervus Dama, L. Smith, in his History of Kerry, notices herds of Fallow Deer as frequenting the “mountains” in that county. But as these are the haunts not of this animal, but of the Stag or Red Deer (C. Elaphus), the latter 362 REPORT—1840. The C. Elaphus, once abundant over Ireland, is now con- fined to the wilder parts of Connaught, as Erris and Conne- mara; and to one or two localities in the South, more espe- cially the vicinity of the lakes of Killarney. Sect. Il. MAMMALIA AQUATICA. Order 6.—PINNIPEDA. Fam. Phocide. Treland. ’ Great Britain. Phocea vitulina, Z. + 0 Phoca greenlandica, Mull. 0 » barbata, Mull. Halicherus Gryphus, Bell. Je 0 Trichecus Rosmarus, ZL. a was probably the species alluded to, especially as in the index to the volume appears “ Deer, red or fallow”. For a long period the Fallow Deer certainly has not been found in any part of Ireland where it could be called truly wild. A horn of this species which I possess, (through the kindness of Edward Benn, Esq., of Glenravel, county Antrim,) is stated to have been dug up from a con- siderable depth in a bog in his neighbourhood, but minute particulars respecting it could not be obtained. It may not be out of place to observe here, that the C. Dama is now well known to inhabit Greece in a wild state. Lord Derby has for some years possessed a pair of these animals of the common spotted variety, which were brought from the neighbourhood of Axium by Lord Nugent, and which, as | aminformed by my friend Mr. Ogilby, who examined them attentively, during a recent visit to their noble owner, differ in no respect from the common Fallow Deer of our parks. Moreover, as re- marked by the same gentleman, the universal application of the word Dama to this animal in the Italian, French, Spanish, and other modern languages de- rived from the ancient Latin, (added to the fact of the animal being still found in the forests of Italy, where there are no parks or inclosures,) points it out as the beast of chase so frequently mentioned under the same name by the Roman poets. Mr. Ogilby likewise remarks that it isin all probability the Platycerus of Pliny, or rather of the Greeks, from whom he copied. It is said in a note to the second edition of the Régne Animal to have been found in the woods of Northern Africa. Cervus Alces, L. A horn of the true Elk (C. Alces), as noticed by me in the « Proceedings of the Zoological Society of London,”’ for 1837, p. 53, was some years since presented to the Natural History Society of Belfast. Tothe donor it was given by a relative residing at Stewartstown, county Tyrone, who attached much value to it as a singular relic dug out of a peat-boy on his own property in that neighbourhood. That it was so obtained I am assured there cannot be a doubt. The horn is that of a very old animal, and quite perfect. On re- © moving the paint with which it was besmeared, the horn certainly presented a fresh appearance; but might not this be attributed to the well-known preserv- ative property of the soil in which it is said to have been found? There is not, that I am aware of, any record of this animal having ever existed ina wild state in the British Isles ; but as it inhabited a wide range of latitude on the continent of Europe, it is within the bounds of probability to believe that it may have been a native species. Sus Scrofa, L. The Wild Boar was at one period common in Ireland, but has long since become extinct. Giraldus remarks that it was of a small race, — but tusks of this animal dug up in our bogs are often of goodly dimensions. | \ | ON THE FAUNA OF IRELAND. 363 "| P. vitulina and Hal. Gryphus only, in this family, have with certainty been recognised as Irish species; they both in- habit the coasts from north to south. - _ Precise information is much wanted with reference to P. _barbata as a British species ; and as such, P. graenlandica (or the animal so considered to be) is a recent addition to the ca- talocue. Trich. Rosmarus very rarely occurs in the Hebrides and in the Orkney and Shetland Islands. Order 7. CETE. Fam. Delphinide. Lreland. Great Britain. Delphinus Delphis, L. + 0 Delphinus Tursio, Fabr. Phoczena communis, Less. + », Orca, F. Cuv. a » Melas, Bell. 0 Beluga leucas, Bell Hyperoodon Butzkopf, Lacep. + 0 Diodon Sowerbei, Jard. 0 Monodon Monoceros, Z. D. Delphis, P. communis and P. Orca are considered to pre- vail on various parts of the coast of Ireland, the second to be the most common, the last the rarest ; of all, I have seen native “specimens, but cannot from personal knowledge speak of the comparative abundance or scarcity of the species. P. melas has been observed on the western and southern coasts; Hyp. Butzkopf along the eastern coast. The four Delphinide which cannot be enumerated in the Irish catalogue are very ‘are as British species; of Diodon Sowerbei a single speci- “men only is on record. Fam. Balenide. + Ireland. Great Britain. _ Physeter macrocephalus, Z. a as Tursio, LZ. + Balena Mysticetus, L. + _ Balznoptera Boops, Flem. + _ According to Dr. Molyneux*, the ‘‘Spermaceti Whale” as been captured on the north and north-west coasts. Smith tices one, taken near Youghal; and Rutty, in his Natural distory of Dublin, mentions an individual as cast ashore in 766. Templeton states that Phys. Tursio is of occasional oc- currence in the West. Bal. Mysticetus has been rarely cap- tured on various parts of the coast. Of a Balenoptera (Ba- léna rostrata) which was taken on the western coast some years ago a very full account has been published by Dr. Jacob in the Dublin Philosophical Journal. * Phil. Trans., vol. xix. 1795-6, p. 508. 364 REPORT—1840. PART III. Class AVES. Order 1.—RAPTORES. Fam. Vulturide. Ireland. Great Britain. 0 Neophron Percnopterus, Sav. This bird has a place in the British Fauna from its occur- rence in England on one or two occasions. Africa is its head quarters. Fam. Falconide. Ireland. Great Britain. Aquila Chrysaétos, Vig. Halizetus albicilla, Sedby. Pandion Halizetus, Sav. Astur palumbarius, Bechst. (?) Accipiter fringillarius, Ray. Falco greenlandicus, ZL. Hancock. Islandicus, Lath. Hancock.(?) »» peregrinus, L. »» Subbuteo, Z. » rufipes, Bechst. » Tinnunculus, L. », salon, Gmel. Buteo vulgaris, Bechst. » Lagopus, Vig. Pernis apivorus, Cuv. Circus rufus, Briss. cyaneus, Fem. 0 ++t+ttt+ttttt+++tt ” Circus cineraceus, Shaw. Milvus Ictinus, Sav. Elanus furcatus, Sav. The two first-named species, the Golden and Sea Eagles are in Ireland, as in Scotland, more numerous than in England. Pandion Halizetus is chiefly confined to the more southern half of the island. Astur palumbarius has a place not only in the older county histories, but in Mr. Templeton’s catalogue; I have not myself seen any specimen which could he verified as native. Accipiter fringillarius, Falco peregrinus, F. Tinnunculus, F. Zésalon, Buteo vulgaris, Circus rufus, and C. eyaneus, inhabit suitable localities throughout Ireland: in the wild and moun- tainous parts of the country which are destitute of wood, B. vul- — garis makes the precipitous rocks its habitation. Falco gren- PER Py PRION ED ID ICI 0 ON THE FAUNA OF IRELAND. 365 landicus as distinguished by Mr. Hancock from F*. Islandicus*, has in one instance been obtained in Donegal}: under the latter name Mr. Templeton records a specimen, killed in the county of Antrim, but as both these terms were then used synony- mously, it must remain doubtful whether it was this or the former species. By this naturalist the F. Subbuteo was on two occasions observed in Ireland. Falco rufipes has once been ob- tained, in the neighbourhood of Dublin. Buteo Lagopus is avery rare winter, as Pernis apivorus is a summer, visitant. Smith, in his History of Cork, (completed in 1749,) remarks of the Milvus Ictinus, ‘These birds are so common that they need no particular description; ...... with us it remains all the year{.” At present the species is unknown in that county. The terms Kite and Goshawk being applied indiscriminately in Ireland to the Buzzards, and the latter sometimes to the Peregrine Falcon, renders it somewhat dubious whether the proper names have always been legitimately employed in the county histories, &. The Milvus Ictinus has, on what was considered sufficient authority, been noticed as an extremely rare visitant to the North §. Of our desiderata, the Circus cineraceus is a species, which from its general resemblance to C. cyaneus, might readily be overlooked ; it will probably yet be added to the Irish cata- logue. Elanus furcatus, an American species, has only twice been taken in Great Britain. Fam. Strigide. 4 Ireland. Great Britain. Bubo maximus, Sibbald. + Otus vulgaris, Flem. + » Brachyotos, Cuv. + Scops Aldrovandi, Will. & Ray. ar ue Surnia nyctea, Dum. 0 Surnia funerea, Dum. Strix flammea, Z. Ulula stridula, Selby. 0 ++ Noctua Tengmalmi, Selby. 0 » passerina, Selby. Of the occurrence of either Bubo maximus or Scops Aldro- vandi in Ireland, there is but a single record. Otus vulgaris * Annals of Natural History, vol. ii. p. 249. + The description of this individual, supplied me, previous to the appearance of Mr. Hancock’s paper, by John Vandeleur Stewart, Esq., of Rockhill, Letterkenny, in whose collection it is, is so ample, as to prove its species beyond any doubt. t Vol. ii. p. 326, 2nd edit. § Ann. Nat. Hist., vol. i. p. 156. 366 REPORT—1840. and Strix flammea are common and resident. Otus Brachyo- tos is a regular winter resident; at the same season Surnia nyctea has occasionally been met with. Ulula stridula is in- cluded in the older county histories; on what was considered sufficient authority it was noticed as an Irish species in Annals of Natural History, vol. i. p. 156. Surnia funerea has its place in the British catalogue from a single individual having been taken off the coast of Cornwall. Noctua Tengmalmi and N. passerina have been very rarely met with in England. Order 2.—INSESSORES. Div. 1.—DENTIROSTRES. Fam. Laniade. Ireland. Great Britain. Lanius Excubitor, Z. + 0 Lanius Collurio, Z. 0 » rufus, Z. The L. Excubitor only in this family can be announced as Trish : its occurrence in a number of instances is on record. LL. Collurio is a regular summer visitant to England; LZ. rufus but a very rare and occasional one. Fam. Muscicapide. Ireland. Great Britain. Muscicapa grisola, L. 0 Muscicapa luctuosa, Temm. M. grisola is a regular summer visitant to Ireland. M. luctuosa is in England considered only as an occasional visitant (Selby). Fam. Merulide. Freland. Great Britain. Cinclus aquaticus, Bechst. Merula viscivora, Selby. © pilaris, Selby. 4) musica, Selby. 35 iliaca, Selby. » vulgaris, Ray. » torquata, Selby. 0 +++4++44 Merula Whitei, Jard. Oriolus Galbula, Z. + Cinclus aquaticus, Mer. musica and M. vulgaris are com- mon and resident; so likewise is M. viscivora, but not to the same extent, although its increase in Ireland of late years has Se.” -:~S-:~--r—r io ee SP anna ON THE FAUNA OF IRELAND. 367 fully kept pace with that in Great Britain: so mild have been our few last winters, that the song of M. musica was almost daily heard. Mer. pilaris and M. iliaca regularly take up their abode with us in winter, as does M. torquata in summer. Oriolus Galbula has in a few instances been met with in various parts of Ireland, and as far north as Donaghadee, co. Down. Mer. Whitet has on two occasions occurred in England. Fam. Sylviade. Ireland. Great Britain. -Accentor modularis, Cuv. 0 Accentor alpinus, Bechst. Erythaca Rubecula, Swains. Pheenicura Ruticilla, Swains. + = Tithys, Jard. & Selby. 0 Pheoenicura Suecica, Selby. Saxicola Ginanthe, Bechst. - Rubetra, Bechst. + 7 Rubicola, Bechst. + Salicaria Locustella, Selby. + a Phragmitis, Selby. + os arundinacea, Selby. 0 Philomela Luscinia, Swains. Curruca Atricapilla, Bechst. + » hortensis, Bechst. + » cinerea, Bechst. Curruca Garrula, Briss. 0 Melizophilus provincialis, Leach. Sylvia Hippolais, Lath. » sibilatrix, Bechst. (?) » Trochilus, Lath. Regulus Aurocapillus, Selby. 0 ++++ : Regulus ignicapillus, Jenyns. Parus major, L. 5, coeruleus, Z. » palustris, L. » ater, L. -,, caudatus, L. Parus cristatus, Calamophilus biarmicus, Leach. Motacilla Yarrellii, Gould. (M. alba, preceding British authors). Motacilla Boarula, Z. es flava, Ray. 0 ++ ++nNt++4+4+4 Motacilla neglecta, Gould. Anthus obscurus, Zemm.* (Rock Pipit, : oF Brit. authors). Anthus pratensis, Bechst. + “ arboreus, Bechst. (?) ak 0 Anthus Richardi, Viezil. * Not 4. aquaticus, Bechst. See Temm. Man., part iv. p. 929. 368 REPORT—1840. Accentor modularis, Erythaca Rubecula, Saxicola Rubicola, Regulus Aurocapillus, Parus major, P. ceeruleus, P. ater, Mo- tacilla Yarrellii, M. Boarula, Anthus obseurus, A. pratensis are common and resident: in the wilder districts, especially towards the west, M. Boarula is rare. Parus caudatus and P. palustris are likewise resident, but much less common than the preceding species ; the former is increasing with the spread of plantations; the latter is very little known as an Irish bird. Pheenicura Ruticilla is but of occasional and rare occurrence ; Ph. Tithys can only be announced with certainty as having once been met with. Saaicola Ginanthe, S. Rubetra, Sali- carta Phragmitis, Curruca cinerea, Sylvia Trochilus are the most common and widely dispersed of the regular summer visit- ants; Salicaria Locustella should perhaps be included with them, but its retired habits render it less known. Salicaria arundinacea is recorded by Templeton as once seen by him near Belfast, and in a single instance Calamophilus biarmicus has been obtained on the banks of the Shannon. Curruca Atricapilla is probably a regular summer visitant to select localities, and has in several instances been known to winter in Ireland. C. hortensis is with certainty known only as an occasional summer visitant. Sylvia Hippolais and Motacilla flava appear every summer in comparatively few localities over the island. Sylvia Sibilatrix and Anthus arboreus are believed to visit Ireland in summer, but it yet remains to be determined. Of our desiderata, Accentor alpinus, Pheenicura suecica, Regulus Ignicapillus, and Anthus Richardt are only known as rare and occasional visitants to England. Motacilla neglecta cannot without further information be regarded otherwise than a species of occasional occurrence in Great Britain. ‘There is little hope of Parus cristatus being found in Ireland: it is, as a British bird, known only in Scotland, where it especially fre- quents the pine forests. Melizophilus provincialis has been met with only in the more southern halfof England. Of Phi- lomela Luscinia and Curruca Garrula, the former is unknown in the West of that country, and the latter would seem to be- come rare towards the same quarter. With increased atten- tion, more species in this family will doubtless be added to the Irish catalogue. Fam. Ampelide. Ireland. Great Britain. Bombycilla garrula, Bonap. ob An occasional winter visitant to Ireland. » —————e—ee SC Cl ON THE FAUNA OF IRELAND. 369 Order INsEssoREs. Div. 2.—Con1rosTREs: Fam. Fringillide. Ireland. Great Britain. 0 Alauda alpestris, Z. Alauda‘arvensis, Z. + » arborea, Z. + 0 Plectrophanes Lapponica, Selby. Plectrophanes nivalis, Meyer. 5 Emberiza Miliaria, Z. + ‘5 Scheeniculus, Z. + : Citrinella, Z. + 0 Emberiza Cirlus, Z. 0 F hortulana, LZ. Fringilla Coelebs, Z. aS < Montifringilla, L. + + Passer domesticus, Ray. 0 Passer montanus, Ray. Coccothraustes vulgaris, Flem. (Fring. Coccothraustes, Temm.) Coccothraustes Chloris, Flem. Carduelis elegans, Steph. 45 Spinus, Steph. Linaria minor, Ray. ip cannabina, Sw. a montana, Ray. t++4+4+ + 0 Linaria canescens, Gould. Pyrrhula vulgaris, Temm. ns Enucleator, Tem. (?) + Loxia curvirostra, L. Loxia Pytiopsittacus, Bechst. », leucoptera, Gmel. + Alauda arvensis, Emb. miliaria, E. Scheniculus and E. Citrinella, Fring. Celebs, Pass. domesticus, Coce. Chloris, Linaria minor and L. cannabina are common and resident. Alauda arborea, Card. elegans, Lin. montana and Pyrr. vul- garis are likewise resident, but more local than the others. Plect. nivalisisa regular winter visitant to the North of Ireland, but little known in the South ; Fring. Montifringilla is a fre- quent, perhaps a regular visitant at.the same period. Coce. vulgaris, Card. Spinus, and Loxia curvirostra occasionally visit us in winter, the first-mentioned being the most rare, and occurring in the fewest numbers ; the last-named has in some instances bred in Ireland. Pyrr. Enucleator would seem from a note of Mr. Templeton’s to have been once met with near Belfast. Lowxia leucoptera has been obtained on one occasion. 1840. 2B 370 REPORT—1840. Alauda alpestris, Plect. Lapponica, Emb. hortulana and Loxia Pytiopsittacus* are very rare and occasional visitants to Great Britain. Emberiza Cirlus and Passer montanus are local species in England, the former visiting only a portion of the South. Linaria canescens I have not yet sought to distinguish from its allies. Fam. Sturnide. Ireland. Great Britain. Sturnus vulgaris, LZ. =f Pastor roseus, Temm. + The former species is somewhat local and partially resident ; it abounds in particular localities during winter. The latter is a rare summer visitant, but has been met with in all quarters of the island. Fam. Corvide. Ireland. Great Britain. Fregilus Graculus, Selb. Corvus Corax, L. ye, Corone, L: » Cornix, L. os Frugilegus, L. “F Monedula, L. Pica melanoleuca, Vieill. Garrulus glandarius, Fem. 0 +++++444+ Nucifraga Caryocatactes, Briss. Freg. Graculus is pretty generally diffused over the marine cliffs of Ireland, and rarely inhabits inland localities. All the species of Corvus are resident and common; C. Corone least so. Of Pica melanoleuca it is stated by Smith, in his History of Cork, (1749,) that it “was not known in Ireland seventy years ago, but is now very common}. Rutty, in his Natural History of Dublin, observes respecting this bird, “It is a foreigner, naturalised here since the latter end of King James the Se- cond’s reign, and is said to have been driven hither by a strong wind.”t Garr. glandarius inhabits only some parts of the island, especially towards the centre and south. Nucif. Caryocatactes is but a rare visitant to Great Britain. Ihave heard that it once occurred at Silvermines, co. Tippe- rary. * It is more than probable that some of the later British specimens noticed as this bird were merely ZL. curvirostra, with the point of the lower mandible not extending beyond the profile of the upper. + Vol. ii. p. 330. t Vol. i. p. 308. ae ON THE FAUNA OF IRELAND. 371 Order INSESSORES. Div. 3.—ScANSORES. Fam. Picide. Ireland. Great Britain. 0 Picus viridis, Z. Picus major, LZ. », minor, Z. 0 »» martius, Z. 0 Yunx Torquilla, Z. Owing to the general scarcity of wood, especially old, this family of birds is rare. P. major only can with certainty be in- troduced to our catalogue, and it is but a very rare visitant. *“* Picus varius minor, Lesser Spotted Woodpecker,” is given as one of the birds of the co. Dublin by Rutty*. In Dr. Patrick Brown’s catalogue of the Birds of Ireland it likewise has a place, but was probably copied from Rutty. In Smith’s Water- ford} appears ‘‘ Picus Martis, the Woodpecker, a bird rare in this county :” the P. martius can hardly have been here meant. Picus viridis would appear to be generally distributed in suitable localities in Great Britain, and P. minor to be so in England ; P. martius is a very rare visitant. Yuna Torquilla, one of the summer birds of passage to England, decreases in numbers towards the west of that country. Fam. Certhiade. Treland. Great Britain. Certhia familiaris, Z. + Troglodytes europeus, Cuv. + Upupa Epops, L. ate 0 Sitta europzea, L. Cert. familiaris constantly inhabits the best-wooded districts throughout Ireland ; Trog.ewropeus is common and resident. Upupa Epops is a rare visitant but has been taken in all quar- ters of the island. Sitta europea is somewhat local in England, and towards the West is said to become more rare. Fam. Cuculide. Ireland. Great Britain. Cuculus canorus, LZ. + Coccyzus americanus, Bonap. + The former is a regular vernal migrant to Ireland, and is generally diffused ; the latter has on two or three occasions been obtained in the counties of Cork and Dublin. * Vol. i. p. 302. + P. 338. 2B2 372 REPORT—1840. Order INSESSORES. Div. 4.—FissiRosTREs. Fam. Meropide. Treland. : Great Britain. Coracias garrula, L. + Merops Apiaster, L. + Both species are extremely rare and known only to have oc- curred on two or three occasions in Ireland. Fam. Haleyonide. Ireland. Great Britain. Alcedo Ispida, L. + Is diffused over suitable localities and resident. Fam. Hirundinide. Ireland. Great Britain. Hirundo rustica, Z. ~ pe urbica, Z. -- a riparia, L. + Cypselus Apus, Flem. + + alpinus, Temm. — The three species of Hirundo and Cyp. Apus are regular vernal migrants to Ireland. Cyp. alpinus has been obtained once off Cape Clear, and again in the county of Dublin. Fam. Caprimulgide. Ireland. Great Britain. Caprimulgus europzus, L. + A regular summer visitant to certain portions of the island both north and south, but very local. Order 3.—RASORES. Fam. Columbide. Treland. Great Britain. Columba Palumbus, Z. ait 0 Columba Ginas, Z. on Livia, Briss. <5 tc Turtur, Z. 0 . migratoria, L. C. Palumbus and C. Livia are common and resident in their very different places of abode. C. Turtur is an occasional summer visitant. C. Ginas is very partially distributed in England, being chiefly confined to the midland and eastern counties. Of C. migratoria a single specimen, supposed to have been in a wild state, has been obtained in Great Britain*. * Phasianus Colchicus, and its var. 8 the Ring-necked, are common in many parts of Ireland to which they have been introduced. ON THE FAUNA OF IRELAND. 373 Fam. Tetraonide. Ireland. Great Britain. 0 Tetrao Tetrix, Z. Lagopus scoticus, Selby. 0 Lagopus mutus, Leach. Perdix cinerea, Lath. » Coturnix, Lath. + In the genera Tetrao and Lagopus, which in the eye of the sportsman if not of the naturalist are of all others the most attractive, we now possess but one species, the Lagopus scoticus. This is common to heathy tracts, from the low- lying bog to the mountain top throughout Ireland, and is in many places as abundant as in the highlands of Scotland. Of the Tetrao Urogallus, Smith, in his History of Cork*, ob- serves, that it is now found rarely in Ireland since our woods have been destroyed. In his Natural History of Dublin, Rutty remarks, that ‘‘ one of these [7. Urogallus] was seen in the county of Leitrim about the year 1710, but they have entirely disappeared of late, by reason of the destruction of our woods+.” In the work above cited, Smith describes the 7. Tetrix as “ frequent.” Mr. Templeton states that he had been in- formed by excellent authority, that “ black game is mentioned in some of the old leases of the county of Down’t; and else- where this bird is noticed as a native. That the species alluded to by Smith was the 7. Tetrix would seem hardly to admit of doubt, as in addition to it he enumerates the Red Grouse. If it were really indigenous, its extinction must, I conceive, be at- tributed to the destruction of our native woods. The Lagopus mutus is not now, nor do I conceive ever was, indigenous to this island. ‘There seems not to be in any part of Ireland a continuity of mountains of sufficient altitude to be suited to the Ptarmigan’s abode. Perdix cinerea is common and resident. P. Coturnix frequents the most highly-cultivated districts in summer, and within the last few years has in certain localities remained throughout the winter. Fam. Struthionide. Treland. Great Britain. 0 Otis Tarda, L. Otis Tetrax, L. 42 The latter species, which is a very rare visitant to Great Britain, has once been obtained in Ireland, in the county of Wicklow a few years ago. O. Tarda is enumerated by Smith * 1749. 7 Vol. i. p. 302. { Magazine of Natural History, vol. i. new series. 374 REPORT— 1840. as one of the birds of the county of Cork; it is long since extinct. Order 4.—GRALLATORES. Fam. Charadriade. Ireland. Great Britain. 0 Cursorius Isabellinus, Meyer. Cidicnemus crepitans, Temm. Charadrius pluvialis, Z. + a Morinellus, Z. + A Hiaticula, Z. 0 Charadrius minor, Meyer. 0 4 Cantiacus, Lath. Squatarola cinerea, Cuv. + Vanellus cristatus, Meyer. _ Strepsilas Interpres, Leach. + Arenaria Calidris, Meyer. + Hematopus Ostralegus, L. + In this family, Van. cristatus and Hem. Ostralegus are com- mon and resident. Char. pluvialis and C. Hiaticula are com- mon and partially resident; the numbers of both species (certain- ly of the former) being much increased by an autumnal migra- tion from higher latitudes. Squat. cinerea, Strep. Interpres, and Aren. Calidris, are regular periodical visitants. dic. crepitans and Char. Morinellus very rarely visit Ireland. Of the Cursorius Isabellinus, four individuals have been obtained in England and Wales. Char. minor has a place in the British catalogue from a single specimen killed in Sussex. To the east and south-east of England only, I believe, is Char. Cantianus known. Fam. Gruide. Treland. Great Britain. 0 Grus cinerea, Bechst. In his History of Cork, Smith states that ‘this bird was seen in this country during the remarkable frost of 1739.” Fam. Ardeide. Ireland. Great Britain. Ardea cinerea, Lath. + », purpurea, L. 0 Ardea alba, L. » Garzetta, L. i) », russata, Wagler. 5, Ralloides, Scop. Botaurus stellaris, Steph. 22 0 Botaurus Mokoho, Vieill. a minutus, Selby. ae Nycticorax europeus, Steph. aS ON THE FAUNA OF IRELAND. 375 Ireland. Great Britain. 0 Ciconia alba, Ray. 0 » nigra, Ray. Platalea Leucorodia, L. + Ibis Falcinellus, Temm. + In this family, the Ardea cinerea only is common and resi- dent; Botaurus stellaris is, in consequence of the improve- ment of the bogs, becoming gradually scarcer, and, as a resi- dent species, is confined to few localities. Bot. minutus, Nyct. europeus, Plat. Leucorodia, Ibis Falcinellus, are rare visit- ants. Ardea purpurea and A. Garzetia have each been once obtained ; of the latter species, one or two other examples in addition to that alluded to*, are said to have occurred on the southern coast. The six British species of the Ardeide which are desiderata in Ireland, are, with the exception of Ciconia alba, very rare visitants ; three of them, indeed, are with certainty placed in the catalogue from their occurrence each in a single instance. Fam. Scolopacide. Ireland. Great Britain. Numenius arquata, Lath. 5 Pheopus, Lath. Totanus fuscus, Leis/. 7 Calidris, Bechst. 3 Ochropus, Temm. 3 Glareola, Temm. (?) By Hypoleucos, Temm. re Glottis, Bechst. Recurvirostra Avocetta, L. Himantopus melanopterus, Zemm. Limosa melanura, Zeisl. ced rufa, Briss. Scolopax Rusticola, L. ” ” ” ” Sabini, Vigors. major, Gmel. (?) Gallinago, L. Gallinula, L. ++ttt+++4t+4¢44+444 0 Macroramphus griseus, Leach. Machetes pugnax, Cuv, Tringa subarquata, Temm. + » variabilis, Meyer. 0 Tringa pectoralis, Bonap. “maritima, Brunn. » Temminckii, Lees. » minuta, Leisl. + » Canutus, Z. 0 » Yufescens, Viedll. 0 Lobipes hyperboreus, Steph. Phalaropus lobatus, Fem. + * See Templeton in Magazine of Natural History, vol. i. new series. 376 REPORT—1840. The word “ resident,” in the sense in which it has hitherto been used, will not apply to any of the Sclopacide. 'The species of which a portion breed in Ireland, and are common at all seasons, are Num. arquata, Tot. Calidris, Scol. Galli- nago, and Trin. variabilis. Tot. Hypoleucos is a regular summer visitant; at the same season J. Ochropus has occa- sionally been met with, and very rarely 7. Glarcola*? The regular autumnal migrants are Num. Pheopus, Tot. Glottis, Lim. rufa, Machetes pugnax, Trin. subarquata}, T. minutat, T. Canutus ; and to these probably Lim. melanura might with propriety be added. In the North of Ireland these species are met with for a longer or shorter period during autumn, and generally move southward on the approach of winter: to this there are, however, occasional exceptions, in some remaining behind; to 7. Canutus and T. Glottis this more especially applies. Num. Pheopus is, in consequence of being in large flocks, much better known upon our coasts in spring when migrating northwards, than in the autumn, when it appears only in small numbers. Scol. Zusticola and S. Gallinula come from more northern latitudes to abide the winter; the former has of late years bred in various parts of Ireland}. col. Sa- bint, Trin. maritima, and Phal. lobatus, have on several occa- sions been obtained ; 7’. maritima is probably a regular winter visitant. Recur. Avocetta and Him. melanopterus have twice been noticed. Tot. fuscus is on record, froma single example having occurred: this species may have escaped notice from its geueral similarity to the common Tot. Calidris. Scol. major should not perhaps be included even with a mark of doubt, as I have not seen any example of it, killed in Ireland, but sportsmen have described birds to me that can hardly be any other, and have correctly remarked on the peculiarity of habits in which they differed from the Scol. Gallinago. Of our desiderata in the Scolopacide, Tr. pectoralis has once, and Tr. rufescens twice, been obtained in England ; Macr. griseus is a ‘‘ very rare,” and Tr. Temminckii an ‘ oc- casional visitant” to that country. Lobipes hyperboreus is in Great Britain chiefly confined to the more northern isles and coasts of Scotland. Fam. Rallide. Treland. Great Britain. 0 Glareola Pratincola, Leach. Rallus aquaticus, L. + * See Annals of Natural History, vol. v. p, 8. + Ibid., vol. iv. p. 285. + Annals of Natural History, vol. ii. ON THE FAUNA OF IRELAND. 377 Ireland. Great Britain. Crex pratensis, Bechst. + » Porzana, Selby. + 0 Crex Baillonii, Selby. 0 », pusilla, Selby. Gallinula Chloropus, Lath. + Fulica atra, Z. + R. aquaticus and the two last are resident and common, as the species ordinarily are in other countries. Crea pratensis is a regular summer visitant, and abundant; C. Porzana a species of occasional occurrence at the same season. Of Glareola Pratincola, four individuals are on record as British. Crex Baillonii and C. pusilla are very rare visitants to England. Order 5.—NATATORES. Fam. Anatide. Sub-Fam. Anserine. Treland. Great Britain. Anser palustris, Flem. + » ferus, Flem. ae » Erythropus, Flem. + » Bernicla, Flem. : + » Brenta, Flem. + 0 Anser ruficollis, Pall. 0 Plectopterus Gambensis, Steph. Cygnus ferus, Ray. + » Bewickii, Yarr. + A. ferus (A. Segetum, Steph.), A. Erythropus (A. albifrons, Steph.), 4. Bernicla and A. Brenta are regular winter visitants to Ireland, the two last, but more especially 4. Brenta, being in great numbers in their very different places of abode. 4. palustris (A. ferus, Steph.) is much more rare than the two first mentioned : at one period it bred in this country, but has long since ceased to do so. Wild Swans are seen every winter in some parts of Ireland, but it cannot be positively stated of either C. ferus or C. Bewickhii, that it is a regular winter visitant ; that one or both may be so considered is a fair inference, from the same lakes being annually visited by ‘ wild Swans.” Of both species I have seen examples, which were obtained in the north, east, and west of the island; C. Bewichzi is of much more frequent occurrence than C. ferus. ‘The Egyptian Goose (Anser egyptiacus) and Canada Goose (Anser Canadensis) have at different times been shot on the Irish coast: the former species had doubtless escaped from ponds; the latter, too, had in all probability done so. 378 REPORT—1840. A. ruficollis is a very rare visitant to England. A. Gamben- sis has been but once obtained, and whether the individual so recorded was a wild bird is very questionable, as the species does not appear to have been met with on the European con- tinent. Fam. Anatide. Sub-Fam. Anatine. Ireland. Great Britain. Tadorna Vulpanser, Flem. a8 0 Tadorna rutila, Steph. Spathulea clypeata, Flem. Chauliodus Strepera, Sw. Anas Boschas, L. Querquedula acuta, Selby. Crecca, Steph. Circia, Steph. 0 ” ++++4+4 a Querquedula glocitans, Vigors. Mareca Penelope, Selby. Three species, 7. Vulpanser, A. Boschas, and Q. Crecca, may be called resident from their breeding in Ireland and being met with at all seasons; but of the numbers of the two last which are here in winter, but a small proportion is bred in the country. Spat. clypeata is most probably indigenous, as in England. It has occurred in Ireland in May, and I once obtained an adult female, shot in July. Querq. acuta and Mar. Penelope are regular winter visitants. Chaul. Strepera and Querg. Circia (A. Querquedula) are of rare occurrence at the same season; of the latter I have not myself seen a duly-authen- ticated Irish example; it is noticed in Tighe’s Kilkenny, and in a catalogue of the Birds of Dublin supplied me by Mr. R. Ball. Tad. rutila and Querq. glocitans are extremely rare visit- ants to England. Fam. Anatide. Sub-Fam. Fuliguline. Ireland. Somateria mollissima, Leach. spectabilis, Leach. Oidemia fusca, Flem. » higra, Flem. 0 Fuligula ferina, Steph. 0 0 » Marila, Steph. » cristata, Steph. Clangula vulgaris, Leach. 0 Harelda glacialis, Steph. Great Britain. ins A: _ + Fuligula rufina, Steph. a. » Nyroca, Steph. » dispar, Steph. + + a. Clangula histrionica, Steph. ie ae ee _— |, ON THE FAUNA OF IRELAND. : 379 The three species of Fuligula noticed as Irish, and Clang. vulgaris, are regular winter visitants: Oid. nigra and Har. glacialis would likewise seem to be so, but in very small num- bers; for four winters successively I have obtained a single specimen of the last in Belfast Bay. Oid. fusca, Som. mollis- sima, and SS. spectabilis, can only be noticed as very rare visitants ; once only has the last been obtained *. Ful. rufina has in a very few instances occurred in England. F, Nyroca is but a rare and occasional visitant; and F. dispar has once been procured. Clang. histrionica is likewise very rare. Fam. Anatide. Sub-Fam. Merganine. Ireland, Great Britain. Mergus Merganser, L. + » Serrator, Z. + 0 Mergus cucullatus, Z. » albellus, Z. + M. Serrator is indigenous, nestling on islets both of marine and fresh-water loughs. M. Merganser is a regular, and M. albellus an occasional winter visitant. M. cucullatus has a place in the British catalogue from the occurrence of a single specimen. Fam. Colymbide. Ireland. Great Britain. Podiceps cristatus, Lath. » Trubricollis, Lath. », cornutus, Lath. » auritus, Lath. » minor, Lath. Colymbus glacialis, Z. » arcticus, Z. » Septentrionalis, Z. ++++4++++4 Pod. minor is common and resident; P. cristatus is more rare, but resident on the larger lakes; P. rubricollis is known only as a rare visitant; P. cornutus is not of uncommon occur- rence in winter, at which season P. auritus more rarely occurs. These two last species are most probably indigenous, as in England, but they have not come under my cognizance in summer. Col. glacialis and C. septentrionalis are regular winter visitants; C. arcticus is much more rare, but occasion- ally met with at the same season. * The specimen is in the collection of Mr. R. Ball. 380 REPORT—1840. Fam. Alcide. Treland. Great Britain. Uria Troile, Lath. », Brunnichii, Sabine. » Grylle, Lath. Mergulus melanoleucos, Ray. Fratercula arctica, Steph. Alea Torda, Z. », impennis, L. Uria Grylle is a resident species. U. Trotle, Frat. arc- tica, and Alea Torda, are regular summer visitants, having breeding-haunts around the coast: either or both of the two | former I am disposed to believe may occasionally be found in small numbers in the bays of Ireland during winter. Uria Brunnichii is noticed by Major Sabine as seen by him in the month of July on the coast of Kerry*, where it may be pre- sumed to breed. By this able ornithologist, the Merg. me- lanoleucos (M. Alle) was observed at the same time with U. Brunnichit; here it also may have its nestling-places ; in two instances I know of this bird having been shot on the coasts of Wexford and Kerry. Of Alcea impennis, a single specimen is on record as Irish. ++t++4+4++ Fam. Pelecanide. Treland. Phalacrocorax Carbo, Steph. ma cristatus, Steph. Sula Bassana, Briss. Great Britain. + + + The first two are common and resident. Sula Bassana is common on the coast of Ireland in summer and autumn; the in- dividuals which frequent the northern parts have their breed- ing-haunts in Scotland. On the Irish coast this species breeds only on one of the Skelig islands off Kerry. Fam. Laride. Great Britain. ‘ Ireland. 0 Sterna Caspia, Pall. Sterna Boysii, Lath. + », Dougallii, Mont. + » Hirundo, LZ. + 5, arctica, Temm. + 3; Mminuta, L. a » nigra, L. + Sterna Anglica, Mont. ;, stolida, L. Larus Sabini, Sad. », minutus, Pall. »» capistratus, Zemm. tettast= * Ainsworth’s “ Caves of Ballybunian,” p. 78. ON THE FAUNA OF IRELAND. 381 Treland. Great Britain. Larus ridibundus, Z. Larus atracilla, Z. » Rissa, L. » Canus, ZL. », eburneus, Gmel. (?) » argentatus, Brunn. » fuscus, Z. » marinus, LZ. » AIslandicus, Edmon. » glaucus, Brunn. Cataractes vulgaris, Flem. = Pomarinus, Steph. fe Richardsonii (Lest. Richard- sonii, Sw.) A parasiticus (not Flem., Lest. parasiticus, Temm.) 0 + $+t+4++++4++4+4 + Procellaria glacialis, L. Puffinus cinereus, Steph. 3 Anglorum, Ray. 0 ++ Puffinus fuliginosus, Strickland. Thalassidroma pelagica, Selby. + “a Bullockii, Selby. a St. Dougallii, S. Hirundo, S. arctica, and §. minuta, are regular summer visitants to Ireland, the S. Hirundo and S. aretica being much the most common and widely-distributed species. These two, with S. Dougallii, breed in a small low rocky islet near the entrance to Belfast Bay*. St. nigra is an occasional visitant; and many years ago was known by Mr. R. Ball to breed at a small lake in the county of Cork. St. Boysz is annually shot upon the coast, and may perhaps have breed- ing-haunts in some of the islets that are rarely visited by the naturalist. St. stolida has a place in the catalogue from two specimens having been taken at sea between Tusker Light- house (co. Wexford) and Dublin Bay. Larus capistratus (of British authors), L. ridibundus, L. Canus, L. argentatus, L. fuscus, and L. marinus, are resident species. L. Rissa is a regular summer visitant. LL. glaucus is of occasional occurrence on every quarter of the coast. ZL. Sabini has in four instances been obtained in the bays of Belfast and Dublin; Z- Islan- dicus has twice been noticed}, and ZL. minutus once: of the latter species; an adult bird in summer plumage was shot upon the river Shannon. In the Appendix to Ross’s Second Voyage it is remarked, under the head of Larus eburneus, * §. Dougallit likewise breeds on islets off the Dublin coast. + In March 1832 I saw a specimen of L. Jslandicus in the shop of Mr. Glen- non, bird-preserver, Dublin: it had been sent him early in the winter of 1831- 32, from the West of Ireland. The other example was obtained by the Ordnance Survey in Strangford Lough. 382 REPORT—1840. that ‘‘ this beautiful gull has lately visited the western shores of Ireland,” (p. 35). Capt. James Ross, the author of this Appendix, has informed me that early in the year 1834 he derived that information from Joseph Sabine, Esq., and that he knows nothing of it further than what is published. For some years, however, I have had a note communicated by the late Thomas F. Neligan, Esq., of Tralee, who was well versed in British Birds, that “ in January 1835 he saw a gull in a field near that town, and four miles from the sea, which he was satisfied was the L. eburneus; he watched it for about twenty minutes, and was at first attracted by the ivory tint of its plumage and its black legs.” All the species of Cataractes do in autumn and winter, at least occasionally, visit the Irish coast. Puffinus cinereus has been obtained near Dungarvan, county Waterford, and is believed to breed there. P. An- glorum is known to me only as an occasional visitant ; it would seem to be more rare now in Ireland than formerly, as is the case in other of the British islands: in Harris’s Down and Smith’s Cork it is mentioned. Thal. pelagica is at all times to be met with on the coasts of Ireland washed by the Atlantic, and breeds on several of the islets ranging from north to south of the western coast. Thal. Bullocki (Proc. Leachii, Temm.) has been obtained on various occasions in all quarters of Ireland; it breeds on some of the western islets. Sterna Caspia and St. Anglica have ina very few instances been obtained in England. Larus atracilla, as a British bird, was known only to Montagu, who on two occasions met with it on the coast of Sussex. Proc. glacialis is, except in the North of Scotland, an occasional visitant to the shores of Great Britain; P. fuliginosa has but once been procured in Eng- land. In the preceding catalogue of Irish Birds, all the species noticed by Mr. Selby as indigenous to Great Britain will be found—either as such, or as visitants—except the following: Melizophilus provincialis, Parus cristatus, Emberiza Cirlus, Passer montanus, Picus viridis*, Sitta europea, Columba Gnas, Lagopus mutus. With these may be mentioned three more which are said to have been found in Ireland, but are not now indigenuus—Picus minor, Tetrao Tetrix, Otis tarda. * T have been assured that this bird is found in some localities in Ireland, but have not scen specimens. we ON THE FAUNA OF IRELAND. 383 PART IV. Crass REPTILIA. Order 1.—TEsTUDINATA. Treland. Great Britain. Chelonia Caouana, Schw. 0 Chelonia imbricata, Schw. 0 Sphargis coriacea, Gray. A single specimen of C. Caowana has been taken alive on the coast of Donegal*. In the British catalogue this species has a place from the occurrence of an individual on the Devonshire coast. C. imbricata and §. coriacea have each been obtained on three occasions on the coasts of Great Britain. Order 2.—Saurtia. Ireland. Great Britain. 0 Lacerta agilis, Z. Beil. Zootoca vivipara, Wagl. Beil. ‘ == Z. vivipara prevails over the island. Lacerta viridis, stated by Ray to have been found in Ireland, is at present quite un- known. Mr. Bell in his “ British Reptiles” suggests that ‘“a green variety of L. agilis, L.., was probably alluded to: this is more likely than that the true L. viridis was meant; but the L. agilis, L., has not been distinguished as an Irish spe- cies.” It has but lately been added to the British Fauna, and from specimens obtained in the South of England. Order 3.—OpruHipIA. Ireland. Great Britain. 0 Anguis fragilis, Z. 0 Natrix torquata, Ray. 0 Pelius Berus, Merr. Ireland has ever been free from the presence of Ophidian Reptiles. As there is no physical obstacle to their being indigenous to the island, it can only be said, that as all animals have geographical limits assigned to them, so these have Great Britain as their western boundary within her parallel of latitude. * See Annals of Natural History, vol. v. p. 8. 384 REPORT— 1840. AMPHIBIA. Treland. Great Britain. Rana temporaria, L. Bufo vulgaris, Laur. Bufo calamita, Laur. Triton cristatus, Laur. (?) + 0 Triton Bibronii, Bell. Lissotriton punctatus, Bell. ae - palmipes, Bell. (?) ae Rana temporaria is common throughout Ireland. In Rutty’s ‘Natural History of Dublin,” the Frog is said to have been “brought into this kingdom in 1699 by Dr. Guithers:” from those introduced by this gentleman to the University Park, Dublin, it is considered that all the frogs in Ireland and her islands* owe their origin! Bufo calamita is found in several parts of the county of Kerry, where it is believed to be in- digenous. Triton cristatus is noticed by Templeton; to myself it is unknown. Liss. punctatus occurs from north to south, but is not universally distributed. Liss. palmipes has been so accurately described to me as to warrant its introduc- tion, with a mark of doubt: I have not yet seen examples of it. Bufo vulgaris, though so common in Great Britain, is not found in Ireland. Triton Bibronii is a recently-distinguished British species. PART V. Crass PISCES. (1. Osszt.) PECTINIBRANCHII. Order 1.—AcANTHOPTERYGII. Fam. Percide. Ireland. Great Britain. Perea fluviatilis, Z. + Labrax Lupus, Cuv. 0 Serranus Cabrilla, Cuv. 0 * Gigas, Cuv. 0 Polyprion cernium, Cwv. 0 Acerina vulgaris, Cuv. 0 Trachinus Draco, Z. Trachinus Vipera, Cuv. a Mullus Surmuletus, Z. : ee 0 “ barbatus, Z. * In Achil I have remarked them to be common. 2 2 ON THE FAUNA OF IRELAND. 385 In the family Percide, Ireland would seem to be so deficient that four species only can be announced; of these, Mullus Surmuletus is given on the authority of Dr. Patrick Browne’s Catalogue, published in 1774. The Perca fluviatilis is stated to have been introduced; but this I am disposed to doubt, as the species is so very widely distributed over the island. Labrax Lupus is a well-known fish on the coast, its numbers decreasing northwards. Trachinus Vipera is found from north to south. Of the species unknown to the Irish Fauna, Serranus Ca- brilla and §. Gigas have in Great Britain been noticed only on the coast of Cornwall, and of the latter but a single in- dividual has been procured; Polyprion cernium has been observed only on the south-west coast of England; Mullus barbatus is extremely rare; Trachinus Draco a species only of occasional occurrence, and chiefly on the southern coast*. Acerina vulgaris is said to be common to the rivers and canals in England. Fam. Loricati. Ireland, Great Britain. Trigla Pini, Bl. ts » lineata, Gmel. Bes » Hirundo, Bl. se » Lyra, Z. ae » Gurnardus, L. " ces ry » Cuculus, Bé. fo ci shoals » Peeciloptera, Cuv. + 0 Trigla lucerna, Bruna. 0 Peristedion Malarmat, Cuv. 0 Cottus Gobio, Z. »» Scorpius, L. 4. Le » Bubalis, Zuph. 0 Cottus quadricornis, ZL. Aspidophorus cataphractus, Cuv. 0 Scorpoena norvegica, Cuv. Gasterosteus aculeatus, Z. Ps Pungitius, L. + a5 Spinachia, ZL. + Of the seventeen (reckoning Zrigla Gurnardus and T. Cuculus as one) British species of Loricata here enumerated, Ireland is known to possess all but five; of these, three spe- cies, Trigla lucerna, Peristedion Malarmat, and Cottus qua- dricornis, are late additions, and have as yet been procured only * The term “ southern coast” applied to England, throughout this Report, refers generally to the portion of that country which lies altogether to the South of Ireland. + See Annals of Natural History, vol. ii. p. 413. 1840. 2 386 ; REPORT—1840. on the more southern coast. Sciena norvegica has I believe been taken only from Berwick northwards. Cottus Gobio is said to be common in England. Of Trigla Peciloptera but a single individual, obtained at Youghal, has yet been recognised in the British seas*. Of the Trigle, T. Gurnardus is most common in Ireland, and taken in abundance in the more genial season of the year; next come 7’. Hirundo, T. Pini, and T. lineata, which are procured at different seasons and throughout the winter. 7. Lyra U have not seen in the north, but have observed it in Gal- way market. Mr. R. Ball states that at Youghal it is not uncommon. Of the Cotti, C. Scorpius and C. Bubalis are common around the coast; the latter the more so. Aspido- phorus, Gasterosteus aculeatus, with its varieties +, and G. Spi- nachia, are common from north to south; G. Pungitius is obtained in the north, and in one locality at least, southwards. Fam. Scienide. Ireland. Great Britain. Scizena Aquila, Cuw. 1 0 Umbrina vulgaris, Cuv. A single individual only of S. Aquila is known to have beer taken on the Irish coast; about the Ist of August, 1840, it was captured within the entrance of Cork harbour. The Umbrina vulgaris has but in one instance been recog- nised as a British fish. Fam. Sparide. Lreland. Great Britain. 0 Chrysophrys aurata, Cuz. 9 Pagrus vulgaris, Cuv. 0 Pagellus erythrinus, Cuv. 0 » Acarne, Cuv. Pagellus Centrodontus, Cuv. 0 Dentex vulgaris, Cuv. 0 Cantharus griseus, Cuv. Of the seven British species of the Sparide, I have seen only the Pag. Centrodontus{ in Ireland, where it is common around the coast. A second species appears in several Irish catalogues, and Chrysophrys or Pagrus may perhaps be * Proceedings of the Zoological Society, 1837, p. 61. + Gast. trachurus, semiarmatus, lieurus, brachycentrus, semiloricatus, and spinulosus seem to me varieties of one species. See Annals of Natural His- tory for April 1841. t It is I presume this species which is alluded to by Templeton, under the name of Sparus aurata. ON THE FAUNA OF IRELAND. 387 meant. Rutty mentions Cantharus Rondeletii, quoting Wil- loughby, fig. 5, 1, as a fish taken in Dublin Bay: the species thus referred to is the Cantharus vulgaris*, a Mediterranean fish, and yet unrecognised as British, ‘The reference is pro- bably erroneous. Dentex vulgaris and Pag. Acarne have their place in the British catalogue from the capture of a single individual of each species; the other four have, with the exception perhaps of either Chrysophrys or Pagrus, been taken only on the southern coast of England. A single specimen of Pag. ery- thrinus was procured by Dr. Parnell in the Frith of Forth. Fam. Squamipinnati. Ireland. Great Britain. 0 Brama Raii, Cuv. This is a rare British species. It is enumerated in a list of fishes published in M‘Skimmin’s History of Carrickfergus, but the propriety of the application of the name to this species is doubtful. Fam. Scombride. Ireland. Great Britain. Scomber Scomber, Z. _ + » maculatus, Couch (?) ob Thynnus vulgaris, Cuv. + mn Pelamys, Cuv. + 0 Xiphias Gladius, L. 0 Neucrates Ductor, Cuv. Caranx Trachurus, Lacép. + Zeus Faber, L. + 0 Capros Aper, Lacép. Lampris Luna, Flem. + Coryphzena Morio, Cuv. The four species of Scombride desiderated in the Irish list are all rare British species, and, excepting Xéphias, chiefly found on the southern coast. Scomber Scomber is common around Ireland; Scomber maculatus is stated by a very intelligent correspondent to visit the coast of Connemara in the months of July and August. Caranx Trachurus and Zeus Faber have been obtained from north to south, but are most common on the western coast. Thynnus vulgaris, T. Pelamys, and Lampris Luna, are ex- tremely rare visitants to the Irish as to the English and Scot- tish coasts. * Cuy. and Val., tom. vi. p. 318. 2c2 388 REPORT— 13840. Fam. TVenioidei. Ireland. Great Britain. 0 Lepidopus argyreus, Cuv. 0 Trichiurus Lepturus, Z. ? 0 Trachypterus vogmarus, Cuv. 0 Gymnetrus Hawkenii, Bl.? 0 Cepola rubescens, L. Of the Tenioidei, none can be announced as Irish; all are species of only occasional occurrence on the coasts of Great Britain, excepting the Cepola rubescens, which will doubtless yet be added to the Irish catalogue. On the coast of Ayr- shire, in Scotland, so near to Ireland, it has several times been taken. Fam. Mugilide. Ireland. Great Britain. Mugil Chelo, Cuv. » Capito, Cuv. M. curtus, Yarr. Atherina Presbyter, Cuv. SF Of the Mugilide we probably want only Mugil curtus, of which but one British specimen has been obtained. Mug. Capito has been noticed as Irish, but all the specimens which have come under my own examination were M. Chelo, which is our common Mullet of the north*, Atherina Presbyter is taken from north to south. Fam. Gobiade. Ireland. Great Britain. 0 Blennius ocellaris, B7. Blennius Gattorugine, Mont. oa os Yarrellii, Vai. + 0 5h Galerita, Mont. es Pholis, Z. + Murznoides guttata, Lacép, (Blen. Gunnellus), } Ht Zoarees viviparus, Cuv. 45 Anarrhicas Lupus, Z. a Gobius niger, Cuv. and Val. 0 » Britannicus, Thomp. (G. sit 4 ger, recent British authors). », Ruthensparii, Zuph. (G. Prot m" punctatus, Yarr.) » minutus, Pall. =F » gracilis, Jenyns. a »» unipunctatus, Parnell, + 0 Gobius albus, Parnell. * Capt. Portlock informs me that he submitted drawings of a Mugil taken on the coast of Down or Antrim to Mr. Yarrell, who considered them to represent M. Capito. ON THE FAUNA OF IRELAND. 389 Treland. Great Britain. Callionymus Lyra, L. a 7 Dracunculus, Z. + Of our desiderata here, the Blennius ocellaris and B. Ga- lerita are rare and apparently local on the coast of Great Britain ; the Gobius albus has been taken only in the Solway Firth, and but on one occasion. In Ireland, the Blennius Pholis and Murenoides guttata are very common around the coast; the B. Gattorugine is of occasional occurrence in the north; the B. Yarrellit (B. pal- micornis of Yarrell’s and Jenyns’s works) has been obtained on the Antrim coast by the Ordnance Survey. By Templeton the Zoarces was noticed in one instance; but little is known with certainty of Anarrhicas as an Irish fish. Of the genus Gobius, the G. minutus and G. Ruthensparit (G. bipunctatus, Yarr.) are the most widely diffused in their very different places of abode on our coasts, the former, as elsewhere, the more abundant; G. niger and G. Britannicus* I have only from the more southern portion of the island; G. gracilis and G. unipunctatus are of occasional occurrence with G. minutus. Callionymus Lyra and C. Dracunculus are not unfrequently taken from north to south, the latter the more commonly, Fam. Lophiide. Ireland. Great Britain. Lophius Piscatorius, Z. (common). “Ic Fam. Labride. Ireland. Great Britain. Labrus variabilis, Thomp.} (L. ma- aot culatus, Bloch.) » lineatus, Don. (not specifi- i cally distinct from the last). } 0 Labrus Comber, Gimel. » Variegatus, Gmel. 4. » Vetula, B/.? », trimaculatus, Penn.t 0 Julis vulgaris, Flem. Crenilabrus Tinca, Flem. + FY; Cornubicus, (La- ‘ one brus Cornubicus, : aL Penn). species§. 5 gibbus, Flem. + * Zoological Proceedings, 1837, p. 61. + Zoological Proceedings, 1837, p. 59. { M. Agassiz informs me that ZL. carneus, Risso, of which he possesses a specimen so named by that author, is a distinct species from the L. carneus, Bloch; this latter being identical with LZ. trimaculatus as figured by Donovan. § Magazine of Zoology and Botany, vol. ii. p. 442. 390 REPORT—1840. Ireland. Great Britain. 0 Crenilabrus luscus, Couch. Crenilabrus rupestris, Selby. + oy pusillus, Yarr. + Ns exoletus, Yarr. + Of the British Labride wanting to the Irish list, the L. Comber is a very obscure and little-understood species. Labrus Vetula, Julis vulgaris, and Crenilabrus luscus, have each but ina single instance been obtained on the British coast. Labrus variabilis and Cren. Tinca are common in suitable localities around the Irish coast; Lab. variegatus is as exten- sively distributed, but in very small numbers; Lab. trimacu- - latus has been taken by the collectors of the Ordnance Survey at Portrush near the Giant’s Causeway. Of Cren. rupestris, C. exoletus, and C. pusillus, a few individuals have been pro- cured—the first-mentioned on the north-east and west coast, the second on the north-east, and the last on the south only. Fam. Centriscide. Treland. Great Britain. 0 Centriscus Scolopax, LZ. (extremely rare.) Order 2.--MALACOPTERYGII. Fam. Cyprinide*. Ireland. Great Britain. 0 Barbus vulgaris, Flem. Gobio fluviatilis, Will. Tinca vulgaris, Cuv. (?) + Abramis Brama, Cuv. 0 Abramis Blicca, Cuv. » Buggenhagii, Thomp. ie prinus Buggenhagii, Bl.) + 0 Leuciscus Rutilus, Cuv. 0 + Dobula, Cuv. 0 a vulgaris, Cuv. 0 Fe Lancastriensis, Yarr. 0 *s cephalus, //em. Leuciscus erythrophthalmus, Cuv. 0 A. coeruleus, Yarr. 0 - Alburnus, Cuv. 0 . Phoxinus, Cuv. 0 3 Idus, Cuv. Cobitis barbatula, Z. ae 0 Cobitis Tznia, Z. In the Cyprinide Ireland would seem to be remarkably deficient; and although there is no doubt that some species * The naturalized species are omitted. ON THE FAUNA OF IRELAND» 391 will yet be added to our list, I have little hesitation in con- sidering the waters of this country as deficient in the fishes of this family. Gobio fluviatilis, Abramis Brama, and Leuciscus erythroph- thalmus are common, and widely diffused over the island. Cobitis barbatula is somewhat generally distributed ; Abramis Buggenhagii has as yet been observed only in the river Lagan. Cyprinus Carpio and Tinca vulgaris are in some waters in the country ; but even the latter, which is considered indi- genous to England, is stated to have been introduced to Ire- land. Leuciscus Phoxinus was introduced some years ago near Dublin, and has, I understand, thriven well there*. Fam. Esocide. Ireland. Great Britain. Esox Lucius, Z. + Belone vulgaris, Cuv. + Scomberesox Saurus, Flem. Hemiramphus europzus, Yarr. Exoccetus exiliens, Bi. (? Irish species). The two first mentioned are common; the Scomberesox is apparently rare; Eoceett have been observed on the southern coast, but specimens are not available, that the species might be determined. The fish named provisionally Hemiramphus europeus has not yet been noticed on the Irish coast+}. Fam. Salmonide. Ireland. Great Britain. Salmo Salar, Z. ala » Eviox, Z. + » Trutta, Z. 2s » Fario, LZ. + 3, ferox, Jard. + », Umbla, LZ. onespecies, + » Salvelinus, Don. \ W.T. ++ + Osmerus Eperlanus, Fem. (0) Osmerus hebridicus, Yar. 0 Thymallus vulgaris, Cuv. 0 Coregonus Lavaretus, Fem. * In Rutty’s Dublin (1772) it is remarked of the Cyprinus Carpio, that “it is said to have been first introduced into Ireland in the reign of King James the First.” In the same work it is said of Zinca vulgaris, that it, like the Carp, ‘‘ is found for the most part in ponds, and rarely in the Liffey and Donnybrook rivers.’’ “ Cyprinus Cephalus and C. Barbus” appear in Dr. P. Browne’s list of Irish Fishes, but excepting their names no information is given. + Stlurus Glanis, L., a fish described to me as taken some years ago in a river flowing into the Shannon near its source, exactly agrees with this species. For particular notice see Annals of Natural History, vol. vii. f 392 REPORT—1840. Ireland, Great Britain. Coregonus Pollan, 7'omp. 0 0 Coregonus Willughbei, Jard. 0 re Lacepedeci, Parnell. 0 Scopelus Humboldtii, Cuv. Of the genus Salmo, Ireland possesses all the British spe- cies. There are many valuable fisheries for §. Salar around the coast; of the migratory species, S. Trutta is next in value, and is taken co-extensively with it; the distribution of S. Eriox is yet to be determined; on every side of the northern peten of the island it occurs. S. ferox is common to the arger lakes, as is S. Fario to the rivers and lakes throughout the island. Salmo Umbla or S. Salvelinus (for I regard the fish so called but as one species) inhabits suitable lakes in all quarters. The Osmerus Eperlanus is recorded by Templeton as a fish of occasional occurrence. Coregonus Pollan, as yet known only as an Irish species, inhabits Lough Neagh, Erne, and Derg, and is abundant in the first-named locality. Of the six species of British Salmonide, as yet unknown as Trish, three, Osmerus hebridicus, Coregonus Willughbei, and Cor. Lacepedei, are each known only to a single locality ; Scopelus Humboldtii (if such be the species) has been re- corded but in three instances on the coast of Great Britain; Thymallus is very local in England. This is noticed in Rutty’s Dublin, but evidently in error, as it is made ‘a sea-fish.” Dr. P. Browne enumerates it, perhaps without any better reason; he published in 1774, Rutty in 1772. Coregonus Lavaretus (if properly so named) is found only in Bala Lake in Wales, and some of the northern English lakes. Fam. Clupeide. Ireland. Great Britain. Clupea Harengus, L. 0 Clupea Leachii, Yarr. » Sprattus, 2. 0 » alba, Yarr. » Pilchardus, Bl. + Alosa Finta, Cuv. + yy communis, Cuv. Engraulis Encrasicholus, lem. Clupea Leachii and C. alba have not yet been identified as Irish species; nor has the Engraulis, which is of rare occur- rence on the English coast, been noticed on the Irish. Clupea Harengus, C. Sprattus, and C. Pilchardus prevail around the coast, the last-named in the south particularly ; here also the Alosa Finta is chiefly found. The “ Rock Her- ring,” which according to Dr. Parnell is the name applied in ON THE FAUNA OF IRELAND. 393 Scotland to the Alosa Finta, is enumerated among the Fishes of Londonderry in Sampson’s History of that county. It is however the 4A. communis which is noticed in the Ordnance Survey of Londonderry, and as being ‘‘ not uncommon.” Div. 2.—SUBBRACHIALES. Fam. Gadide. Ireland. Great Britain. Gadus Morrhua, Z. » Callarias, L. » Bglefinus, LZ. » luscus, L. » minutus, Z. Merlangus vulgaris, Cuv. os Pollachius, Cuv. a Carbonarius, Cuv. 0? Merlangus virens, Cuv. Merlucius vulgaris, Cuv. Lota Molva, Cuv. +4+t+4+4+4+4+4+ + 0 Lota vulgaris, Cuv. Motella tricirrhata, Wills. » Mustela, Wills. 0 ++ Motella Cimbrica, Nills. Brosmus vulgaris, Cuv. (?) + Phycis furcatus, Cuv. + Raniceps trifurcatus, Fem. oe { Couchia argenteola, Thomp. 0 (Motella glauca, Gadus argenteo- lus, Mont.) j Couchia minor, Thomp. 0 Of the four British species of the Gadide which we seem to want, one, Motella Cimbrica is a recent addition to the cata- logue, and is yet known only to two localities, both in Scotland ; Lota vulgaris is very partially distributed in England ; Couchia argenteola* has been observed only in Devonshire and Corn- wall; Merlangus virens is unknown to me as a species distinct from M. Carbonarius. Of Brosmus vulgaris I have not seen an Irish specimen, but it is in the list of Fishes given in M‘Skim- min’s History of Carrickfergus. Gadus Morrhua and G. A4iglefinus are common around the Trish coast. Gad. luscus, G. Callarias, and G. minutus are of occasional occurrence from north to south. Merlangus vul- garis, M. Pollachius and M. Carbonarius are common and generally distributed. Merlucius vulgaris is taken around the coast, but is much more common in the south. Lota Molva and the two common Motelle are generally distributed. Phy- * Annals of Natural History, vol. ii. p. 411. 394 REPORT—1840. cis furcatus has but rarely been obtained, and of Raniceps tri- Jurcatus a single individual is on record. Couchia minor has been captured only in Strangford Lough*. Fam. Pleuronectide. Ireland. Great Britain. Platessa vulgaris, Cuv. + » Flesus, Cuv. + »» Limanda, Cuv. + »» | microcephala, Flem. + $5) hola, Cun: 0 Platessa Limandoides, Jen. 0 » elongata, Yarr. Hippoglossus vulgaris, Cuv, + Pleuronectes maximus, Z. + oe Rhombus, Z. + ” punctatus, Bi. se si hirtus, Mull. + a Megastoma, Don. + 0 Pleuronectes Arnoglossus, Schn. Solea vulgaris, Cuv. + 0 Solea Pegusa, Yarr. r » Lingula, Rond. + »» Variegata, Flem. + All but four species of the British Plewronectide have been noticed on the coast of Ireland; of these the Platessa Liman- doides and Plat. elongata are late additions to the British ca- talogue; the former has been taken on the eastern coast of Scotland and South of England ; the latter but in one instance, and a single specimen at Bridgewater. Pleuronectes Arno- glossus}+, and Solea Pegusa are species of occasional occur- rence, and, as British, are known only to the southern coast of England. Platessa vulgaris, P. Flesus and P. Limanda are common around the Irish coast, the last not numerous; P. microce- phala is widely distributed, but in numbers very limited. P. Pola appears to be a local fish, but tolerably numerous where it does occur ; from the eastern coast only have I seen speci- mens. Hippoglossus vulgaris is occasionally met with from north to south. Pleuronectes maximus and P. Rhombus are common around the coast; P. Megastoma is not of unfrequent occurrence; P. punctatus and P. hirtus have each been once obtained in the north-east of the island. Solea vulgaris is common around the coast; S. Lingula I have seen a few speci- mens of from every side of the island; S. vartegata has been taken in Belfast Bay. * Annals of Natural History, vol. ii. p. 408. + This is enumerated in M‘Skimmin’s list, but probably erroneously. ON THE FAUNA OF IRELAND. 395 Fam. Discobolt. Ireland. Great Britain. Lepadogaster Cornubiensis, Flem. a bimaculatus, Flem. as cephalus, Thomp. Cyclopterus Lumpus, L. Liparis vulgaris, Fem. (?) » Montagui, Flem. +++ 04+ In this family Ireland would seem to possess one species more than Great Britain, Lepadogaster cephalus, which was described from a specimen taken on the western coast*. Le- padogaster Cornubiensis is a local species known to inhabit the coasts of Antrim and Clare; L. bimaculatus is taken on the eastern and western coasts by dredging in deep water; Cyelo- pterus Lumpus is common from north to south. Of Liparis vulgaris I have not seen any Irish specimen; it is stated in the Ordnance Survey of Londonderry to have been procured at * Lough Foyle and Larnet;” of LZ. Montagui, I have seen a few specimens which were taken on every side of the island. Fam. Echeneide. Ireland. Great Britain. 0 aero Remora, Z. (taken in a single instance.) Div. 3—APODES. Fam. Anguillide. Ireland. Great Britain. Anguilla acutirostris, Yarr. + » latirostris, Yarr. + Be mediorostris, Yar. (?) + 43 Conger vulgaris, Cuv. 0 Murena Helena, Z. Leptocephalus Morrissii, Penn. Ophidium imberbe, Z. (?) Echiodon Drummondii, Thomp. Ammodytes Tobianus, Z. a Lancea, Cuv. The Murena Helena only of the British Anguillide is cer- tainly wanting to the Irish catalogue ; there is but one recorded instance of its capture on the coast of Great Britain. The Echiodon, of which a single individual was discovered on the Irish coast, has not yet been met with elsewhere. An- ++o++ * Annals of Natural History, vol. iii. p. 34. t One of these specimens, kindly offered to my inspection by Capt. Port- lock, though not well marked as Z. Montagui, I considered to be of this species. 396 REPORT—1840. guilla acutirostris, A. latirostris and A. Conger are common and in suitable localities, especially the first and last generally- distributed species. Of the A. acutirostris there are several va- luable fisheries in Ireland. A. mediorostris is marked with doubt from a want of accordance in the one osteological character of the specimen examined with that attributed to the species; in every other character and in habit examples taken in the North of Ireland agree with it. Leptocephalus Morrissit has, in a few instances, been taken on the north- eastern, southern and western coasts. Templeton notices the Ophidium imberbe of Pennant as once obtained by him. Ammodytes Lancea is common on sandy coasts around the island; A. Tobianus has only as yet been recognised on the Down coast, where it is well known. LOPHOBRANCHII. Order 3.—OsTEODERMI. Fam. Syngnathide. Ireland. Great Britain. Syngnathus Acus, DL. ss Typhle, Z. 5 zequoreus, L. ~ anguineus, Jenyns (“S. Ophidion, Boch.) f 0 + +++ Syngnathus Ophidion, L. - lumbriciformis, Jenyns. Hippocampus brevirostris, Cuv.? All of the British Syngnathide except S. Ophidion, Linn., are known as Irish. Syng. Acus and S. lumbriciformis are the most common around the coast. S. Typhle, S. equoreus, and S. anguineus may be considered as rare, but have been taken both in the north and south. There is indubitable evi- dence of the occurrence of the genus Hippocampus more than once on the Irish coast, but the species cannot be announced : I have not myself seen any examples. ++ Order 4.—GyMNODONTES. Fam. Gymnodontide. Ireland. Great Britain. Tetrodon stellatus, Don. ab Orthagoriscus Mola, Schn. + 0 Orthagoriscus oblongus, Schn. Templeton has recorded the occurrence of Yetrodon stel- Jatus in one instance on the coast of Waterford. Orthagoris- cus Mola has occasionally been captured on every side of the island; O. oblongus has not been recognised as an Irish fish. ON THE FAUNA OF IRELAND. 397 Order 5.—ScLERODERMI. Treland. Great Britain. 0 Balistes Capriscus, Gmel. (a single specimen.) II. CARTILAGINEI. Order 6.—ELEUTHEROPOMI. Treland. Great Britain. Acipenser Sturio, L. (’) + or Thompsoni, Ball, MS. 0 0 Acipenser latirostris, Parnell. Mr. R. Ball is of opinion that one or two Irish examples of Acipenser, which he has critically examined, are not only dis- tinct from the two species which have been recognised as Bri- tish, but are undescribed : he has named the species 4. Thomp- soni, and is about to publish a communication on the subject in the Proceedings or Transactions of the Royal Irish Academy. Sturgeons are occasionally, though very rarely, taken in all the larger rivers of Ireland, but I have not had the opportunity of examining them critically as to species. Order 7.—ACANTHORRHINI. Ireland. Great Britain. 0 Chimera monstrosa, Z. (taken only in the Shetland Islands), Order 8.—PLAGIOSTOMI. Fam. Squalide. Ireland. Great Britain. Scyllium Canicula, Cuv. as a stellaris, Cuv. as Pristiurus melanostomus, Bonap. (Scyllium melanostomum, Bon.) By 0 Carcharias vulgaris, Cuv. Carcharias Vulpes, Cuv. (?) + . glaucus, Cuv. + Lamna Cornubica, Cuv. one » Monensis, Cuv. : species? a Galeus vulgaris, Cuv. + Mustelus levis, Cuv. + Selachus maximus, Cuwv. su Spinax acanthias, Cuv. + Scymnus borealis, Flem. 0 Echinorhinus spinosus, Blainv. 0 Zygzena malleus, Val. Squatina Angelus, Dum. + Of the four Sgualide which cannot be announced as Irish, the 398 REPORT—1840. Carcharias vulgaris has not been properly established as a British species ; the Zygena malleus has but once been taken ; Scymnus borealis twice, and in both instances north of the mainland of Scotland. Echinorhinus spinosus is a late addi- tion to the British catalogue, and has been obtained in different localities on the English coast. Scyllium Canicula, Spinax acanthias, Mustela levis and Galeus vulgaris are the most common species; the first the most so, the others becoming less so in the order in which they are set down. They are found from north to south. Carcha- rias glaucus, Lamna Cornubica or Monensis (these I am dis- posed to believe are but one species), and Squatina Angelus are of occasional but rare occurrence from north to south. Templeton notices Scyllium stellare as taken occasionally ; and Carcharias Vulpes as having been seen about the Copeland Isles, near the entrance of Belfast Bay. Selachus maximus, the ** Sunfish” of Ireland, and so valuable for its oil, prevails on the western and southern coasts, but chiefly on the former. Of the Pristiurus melanostomus, two individuals have been ob- tained by the collectors of the Ordnance Survey at Portrush, near the Giant’s Causeway*. Fam. Raitide. Ireland. Great Britain, Torpedo Walshii, Thomp. MS. Te Raia Batis, L. + », Oxyrhynchus, Mont. (Smith’s } ie Waterford.) 0 Raia marginata, Flem. » chagrinea, Mont. » maculata, Mont. 0 »» microcellata, Mont. » Clavata, Will. 0 » Yadiata, Don. 0 » intermedia, Parnell. » Yradula, Delar.t Trygon Pastinaca, Cuv. a * Captain Portlock, in contributing a notice of this Shark, observed, that “in the work of Miiller and Henle the genus Pristiurus, Bonap. is described as having a row of small prickles on the tail-fin, and Scyllium Artedi is figured and described by Risso as having but a single row. In Yarrell’s description of Scyll. melanostomum, two rows are mentioned, and in our specimens they certainly exist. Ought not, therefore, the single row to be dropped as a generic character, and Risso’s termination of his specific characters used, viz. ‘ pinna dorsi extremitate [supra] spinosa’? May not the one and two-roed indivi- duals be of distinct species, and the black mouth be common to both ?” + Captain Portlock informs me that accurate drawings of a species of Ray, obtained during the Ordnance Survey of Antrim, and submitted to Mr. Yarrell and Mr. Couch, were considered by these naturalists to represent this species. ON THE FAUNA OF IRELAND. 399 Ireland. Great Britain. 0? Myliobatis Aquila, Cuv. Cephaloptera Giorna, Risso. 0 Of our desiderata in this family, R. marginata and R. radi- ata are rare species, and only of occasional occurrence, the former on the English; the latter on the Scottish coast. Of R. microcellata and Myliobatis Aquila, not more than two or three British examples are on record. Raia intermedia is one of Dr. Parnell’s recent additions from the Frith of Forth. Raia clavata, R. Batis, and R. maculata are taken from north to south of Ireland; the first is the most common on the north-east coast. R. Oxyrhynchus is included from being no- ticed in Smith’s History of Waterford. R. chagrinea and R. radula are additions made to our catalogue by the Ordnance Survey, and have both been taken on the north-east coast. In contributing these species Captain Portlock remarks, that “the former seems to take the place of R. Oxyrhynchus on the northern coast,” and that of R. radula he lately saw a speci- men which was procured in Dublin Bay. The Torpedo, of which I have seen Irish specimens, is identical with that from the coast of France, figured by Walsh in the Philosophical Transactions ; and which in the present confused state of the genus, it might be desirable, for the sake of distinction, to term Torpedo Walshii*. Cephaloptera Giorna has a place in the general British catalogue from a single individual taken on the southern coast of Ireland. The Rays are less known in Ireland than most other fishes, in consequence of their being rarely brought to market, and when so to their being in an im- perfect state. Order 9.—CycLostTomt. Fam. Petromyzide. Ireland. Great Britain. Petromyzon marinus. ZL. + BS fluviatilis, Z. + bs Planeri, Bi. + Ammocoetes branchialis, Cuv. + Myxine glutinosa, Z. + In this family Ireland possesses all the British species. P. marinus ascends several of the rivers around the coast. P. Planeri occurs from north to south, and is more common than P. fluviatilis. Ammocoetes branchialis is likewise widely distributed. Myxine is said by 'l'empleton to have been found at Carrickfergus. * For a particular notice on this subject, see Annals of Nat. Hist. vol.v. p. 292. 400 RERPORT— 1840. Finally, the species of Vertebrata which appear at present to be peculiar to Ireland, are six in number; two Mammals, Mus hibernicus (not yet properly established as a species) and Lepus hibernicus; and four Fishes, Coregonus Pollan, Couchia minor}, Lepadogaster cephalus, and Echiodon Drummondii. Further investigation will, in all probability, show that some of these species are found elsewhere. PART VI. Conclusion. In addition to the foregoing comparative catalogue, it has been thought desirable that a catalogue proper, or one con- taining the Irish species only, should be appended to this Report. It here follows, and with it are local lists :—of these, a few more could have been given, but the six which are intro- duced comprise all that were considered necessary for the present purpose. The idea of giving these occurred so late, that there was not time to perfect them, but in so far as they extend they are believed to be critically correct. The columns headed “‘ Elsewhere in North,” &c. are added for the recep- tion only of such species as are not found in the restricted localities comprised in the one or two preceding columns. For the Belfast list I am myself accountable, together with the greater part of what is contained in the columns headed “Elsewhere,” &c. The list for ‘‘ N. W. Donegal” is derived from Mr. John Vandeleur Stewart's contribution to the 5th vol. of the Magazine of Natural History on the Mammalia and Birds of that district: additions made since its publica- tion have been kindly communicated to me by Mr. Stewart, and are included; at his desire likewise some two or three species noticed in his published catalogue are here omitted. The lists for Dublin and Youghal were contributed by Mr. Robert Ball. ‘‘ West of Connaught” is derived from different sources; ‘‘ Tralee” from a list favoured me some years ago by an ardent and accurate naturalist, Mr. Thomas F. Neligan, since deceased. ‘The distance of twenty miles round Belfast, Dublin, and Youghal is comprised in the respective catalogues. The ? throughout the columns implies doubt as to species, and not as to habitat; the * denotes presence. + Mr. Yarrell, perhaps judiciously, considers this too minute to be satisfac- torily characterised as a species. The difference, however, in size between it and Gadus argenteolus, Mont., is so trivial, that if the one be acknowledged, the other has all but equal claims to be so. ON THE FAUNA OF IRELAND. MAMMALIA. Vespertilio Pipistrellus...... Plecotus auritus............... Sorex rusticus............ saateas Tetragonurus or Meles Taxus ... Lutra vulgaris . Mustela vulgaris* . a: erminea ... sd Martes Foina. za Abietum... Vulpes vulgaris Mus sylvaticus . Musculus. ans Rattus *.... ——— hibernicus ....ccccecccses Gecumanus.........++.... Lepus hibernicus .... ........ Cuniculus..............6. Cervus Elaphus............... Phoca vitulina .......s.seese Halicherus Gryphus...... beg Delphinus Delphis...... Phocena communis ......... Hyperoodon Butzkopf ...... Physeter macrocephalus? ... ADUUSIO aj co0tsssaunavensae Balzna Mysticetus .......... Balznoptera Boops (‘“ Ba- lena rostrata”) ............ Belfast. | *** * * Pee 23) Erinaceus europzus .........] N.W. Donegal. Elsewhere in North. 7 : * A ° Dublin Elsewhere in East. cee eH * West of Connaught. Elsewhere in West. oF * * * 1 * AR ice Ae oe Oe ae *x¥ xX * * * ~~ * Youghal. +e # * Elsewhere in South, AVES. Aquila Chrysaétos ............ Halizetus albicilla.......... Pandion Halizetus Astur palumbarius?*......... Accipiter fringillarius . ..... Falco greenlandicus .......... Islandicus? peregrinus —— Subbuteo rufipes ...... Sceeeonceaeds — Tinnunculus............ Hlisalon ......2. s0e.see. Buteo vulgaris .............. os Lagopus ........ssse0ee0. Pernis apivorus .............+. Circus rufus .....0......000008- cyaneus ...... sneestidns de * * x4 *# * ® [ot * * * xX * Ke KKK XK * * * * * See preceding remarks on, 1840. > Rutty’s Dublin. 2D © Templeton. 402 REPORT— 1840. & ) nM ae | West. - South. Elsewhere in North. Elsewhere in East. West of Connaught. Elsewhere in West. Tralee. Elsewhere in South, AVES. | | | Milvus Ictinus® Bubo maximus ... Otus vulgaris ...... wee * eee eee ee eee * * * aes * ase vee cae * oo | ok Lanius Excubitor .......-+-+++ Muscicapa grisola ......++++.- Cinclus aquaticus .......+++++ Merula viscivora .......+0+++: pilaris..... ——=t IYNISICA oe oscsanessas= suse H——. T]1Ca, ...sccecccocesccecees vulgaris .....sesseeereeees torquata .....seerecseveeee Oriolus Galbula.............. Accentor modularis ......... Erythaca Rubecula .......... Pheenicura Ruticilla ......... PItHYS' sancearstees sures Saxicola (Enanthe Beton * * XX KKK ————— —$$—— XXX eK KK . * * * * * HEHHHHHRHEH HEH HHH HK 7 HF == = * *# * eRe * * * Rubicola ..........00000. Salicaria Locustella*......... Phragmitis..........0+06- ATUNCINACEA .....ceeeees Curruca atricapilla............ hortensis.. (CUICLEA lacaccrescsevccesss Sylvia Hippolais............... Sibiatrix 2 > s.pccccc. cone TrochiluSis.ccsecesss sane Regulus aurocapillus.... Parus major .....e.se0+e coeruleus .......066 < PalUstris).c...020..s+ecese- BLL ie astra asusagsiessiecdes caudatus.. ** * see * aoe * wee £3 ~~ *¥ Xe *¥ KKH vee see * * * HHH HKHKHKHKKHH KKH * xx XH HHH * * * Motacilla Yarrellii... Boatula tteict:ctesseocns- HAV al: osastudekioasscracahen Anthus ObDSCUIUS .o..eee-eeeees PYAteNSiS......sesee-eeeees arboreus??*.... Bombycilla garrula . Alauda arvensis .... ATDOTEA ..0cc.scccceree- Plectrophanes nivalis......... Emberiza miliaria ............ * **%& * * eee HE eee * eee aoe eee * ¥HeRHKHRH KKH H* Hee KX * See preceding remarks on, ON THE FAUNA OF IRELAND. 403 at ie e < e wt 2 ie = 2 « &is8/8S]| ¢ | Se] cm] sell = re aiesy & sm skh Pe | ee << o |as ao |-SIES| S |EQ|@s/EE] & | = les wE| oA 3s | o £/]o a c | on A Alecia |ssiFeigs| S| |2e AVES. eS x Shier a Emberiza Scheeniculus ...... Citrinella .. : Fringilla Coelebs. ............. Montifringilla ......... Passer domesticus ............ Coccothraustes vulgaris...... Chloris ..............00086 Carduelis elegans ............. SSDINUS) ak iUecs setae Linaria minor.................. cannabina ..............: montana.... d Pyrrhula vulgaris ............. Enucleator® ............ Loxia curvirostra ............. leucoptera .............4. Sturnus vulgaris........ Pastor roseus .......... Fregilus Graculus ............ Corvus Corax ...........0.0000- Corone® 6.22 .ie elicaeen COM IR ee eenccp teat ess —— frugilegus................ Monedula ,.............. Pica melanoleuca ............. Garrulus glandarius.......... Picus major.................000. Certhia familiaris ............. Troglodytes europzus ... Upupa Epops..............0... Cuculus canorus............... Coccyzus americanus ....... Coracias garrula............6..| 2.6 | oe Merops Apiaster...,....... Alcedo Ispida...... Hirundo rustica .. pa DICH or sells ts cvs vast eS Re PEPARLAS oe sdseNcs ox t'oweh see Cypselus Apus................ BUBOOHSH. sies.c/ai'on evaseens LB osolkaeetill <2 Caprimulgus europzus ......| 4 Columba Palumbus..........| 4 Livia eee e cece eeeeweneenel ge PEOTEUE sce s-.on28 * * See preceding remarks on. 2pd2 —- 404 REPORT—1840. “ a Se Sy ome etersall tea |e = x Trigla Pini............. Bache econ ir: * * lineata A eee ASE Ie * Boa Pex * * —— Hirundo ................ te easel lies * * pe VAY A tslnlnarewnict nelgesricteep's © * * Gurnardus... Cuculus...... * * ts SS Peciloptera ........... eet seellh seat teoed If ees a] pecs ae Cottus Scorpius steNsaudetns dove * = * * REL. Bi balisincin. ds cisas sos. * * * * Aspidophorus cataphractus .| » * ~ |l x ~ il «x Gasterosteus aculeatus .. x « {lox dee * * pungitius ......... < Seal hens — Spinachia ... x * * * Sciena Aquila ...........066:) 0 vee | * * See preceding remarks on. aes, » Given on authority of Dr. Brown’s catalogue, in which no locality is named. — ON THE FAUNA OF IRELAND. 407 North. East. West. South os 2 sj]o : o 2 |ez|| 2 |S8 32/85 || 2 | § a l|2c] A |gslFslasi = la PISCES. ae ae | oa a Pagellus Centrodontus ......| * A | ee | Scomber Scomber ....... * * : * vee | ok maculatus ........s000004] + : ee ll ok Thynnus vulgaris ...... nacchspieastiiier: IL sce Pelamys..........sseeeee Seer i ihieest lees stalne aes ditaaeoona | Meee Caranx Trachurus...... Steet || Pen ey Zeus Faber ..........0.205 * eee fl x * «|x Lampris Luna ......... lee aa shal [eee oe Mugil Chelo ......... SPPRC enue eg eer | ed wae Jee Capito...... eeedunseemasten * Atherina Presbyter .........| x * oll * Blennius Gattorugine ......| x Yarrellii, Val. (B. palmicornis, Yarr. and -| x Jenyns’ Works) ..+.++0+ PH OMe eeacs so.eee- Ss ar Be Bs i ege fee How Murenoides guttata ..... rachllaeu \jes * x [oe | * Zoarces viviparus .... * Anarrhicas Lupus .. weosle ag soil we aati Gobius niger, Cuv. .....+..- 8) Pere * coe ll ox Britannicus, Thomp. (G. niger, recent Brit. a ; x! ‘ swotliftss * AUNOTS) oon. csecnacesevere Gobius Ruthensparii (G. bipunctatus, Yarr.)...... J | * 5 minutus ena maps] ge. [ts S * |" * gracilis ......... % Be ee + > unipunctatus ... * f +S z * Callionymus Lyra ... 2 * oo * Dracunculus .......++++.| 4 ee * * Lophius Piscatorius .........| y * = * Labrus variabilis (L.]) , maculatus, Bi.) se} yews * * * lineatus ............ J) © VAI gGatus .escesecsesvees * a * é * . * trimaculatus ............ - Crenilabrus Tinca......] .. Cornubicus ccc = Ae see fe eace WPsae~ = ful * * . . one * EXOlCtUS ....ssscesensecees * Be * Gobio fluviatilis ............06+] 4 J lise * Tinca vulgaris ............+0- Abramis Brama...........0++-| 4 Salto | ba * Buggenhagii .........--.| 4 LeuciscusErythrophthalmus| , ee thiee Pe ea | Cobitis barbatula ............ Sth Wig * Atha hae Esox Lucius ..... Bowes te teed 5a (eon las 2 UP F ani] tae ~ Belone vulgaris .............-. se * ao | eee Wl wk Scomberesox Saurus ....... ve] eae * Exoceetus exiliens?............ eis 5. : vee | x Silurus glanis?>... ‘ Or Nee @ Possibly introduced —sce preceding remarks on. > See preceding remarks on. 408 REPORT—1840. North. East West. South. F + = (eae gfe) 2 |2el=e/S2| 2 | & eo S |ea|gs|B| & ES o o 3 2 &/g GC) a A lZs||/A |gs|Fe|25| 5 |B5 PISCES. aul pie se Ks Salmo Salar® ........ Rieivatonstiaae - il x » * HATION: sfomecacvapeesaewes |e CU ritbtaerrsp ese gedee suis sh » * * * ee * Fario Cee ccenseccccsocccene ck * owe * * FORD IGN: coe enmeene alte s saree ste « * : wee * —— Umbla, L.......... 3 Salvelinus, Pon. } hale aki Pagal arse ets i Osmerus Eperlanus ......... * Coregonus Pollan ... * * Clupea Harengus * Pei ec prey | ec |p Sprattus .... * safle ve |] x * Pilchardus . * * s+ ll x * (Alosa Binta.v.c.ecss=. See preceding remarks on. i ON THE FAUNA OF IRELAND. 409 Zz ° ee a & p Dm En = n a wm i=) & ct a Belfast Elsewhere in North. Dublin. Elsewhere in East. West of Connaught. Elsewhere in West. Youghal. Elsewhere in South. PISCES. | | | | Anguilla mediorostris ?* Conger vulgaris ............... Leptocephalus Morrissii ..... Ophidium imberbe Echiodon Drummondii Ammodytes Tobianus . Lancea Syngnathus Acus Typhle —— equoreus ....... anguineus ....... fy —— lumbriciformis ......... Hippocampus brevirostris ? . Tetrodon stellatus Orthagoriscus Mola Acipenser Sturio ? ...... Scyllium Canicula stellaris Pristiurus melanostomus Carcharias Vulpes? ......... glaucus ........... Sawaests Lamna Cornubica Monensis Galeus vulgaris . Mustela levis............. cone Selachus maximus .... Spinax Acanthias .......... 5A Squatina Angelus ............ Torpedo Walshii .. Raia Batis ...... Demis asiahic ve Oxyrhynchus........... : chagrinea .. —— maculata clavata * : radula......... Seodccakease Trygon Pastinaca ............ Cephaloptera Giorna Petromyzon marinus ......... fluviatilis xe RRK HK . . % * * Myxine glutinosa ............] ® See preceding remarks on. i wy rh 4 411 \ Report of Experiments on the Physiology of the Lungs and Air-tubes. By Cuarues J. B. Wixttiams, M.D., F.R.S, WHEN at the request of the Medical Section of the British As- sociation, I undertook three years since to investigate experi- mentally several doubtful points respecting the properties and offices of parts of the respiratory apparatus in the higher classes of animals, I hoped to be able to include in the inquiry the che- mical process of respiration, and the vital effects of its interrup- tion. Professional engagements having obliged me to relinquish these points, I have restricted my attention to others more im- mediately bearing on practical medicine. The chief of these are the contractility and sensibility of the air-tubes and lungs. It has long been a matter of controversy whether the lungs ind air-tubes are more than passive in the motions of respiration ; whether they possess any self-contracting or expanding power, independent of the muscles which affect the capacity of the chest. Different writers, both ancient and modern, have main- tained opposite opinions. Laennec, after Sennert, Bremond and others, attributed to the lungs both a self-contractile and self-expansive power, in addition to their mechanical or elastic properties. Haller, on the other hand, was led by experiment to deny that any independent vital motions are exhibited by the lungs of animals, corresponding with those of respiration; and Miller has confirmed these negative results. Within the last few years certain writers in this country and in France*, have denied altogether the muscular contractility of any part of the air-tubes below the larynx. These negative observations are in opposition to the generally- received opinion, derived chiefly from the anatomical researches of Reisseissen, that the circular fibres of the air-tubes, from the trachea to their terminations, are muscular. Very few at- tempts have been made to solve this problem by experiment. Varnier and Wedemeyer only succeeded in exciting partial con- tractions in the smaller bronchi; but after all their results, Miller concludes that “ it is remarkable that there exists at pre- sent no direct proof of the contractility of the wnuscular fibres of the trachea and its branchest.”’ I need scarcely remark, that this subject is by no means one of merely speculative interest. Much of the pathology and * MM. Trousseau and Belloc, Dr. Geo. Budd, &c. + Elements of Physiology, translated by Baly. 412 REPORT—1840. treatment of various diseases of the respiratory organs, espe- cially asthma, is at present founded on the supposition of a muscular contractility of the air-tubes, the very existence of which is stated by one of the most eminent of modern physio- logists to be little more than assumed. The chief objects of the following experiments were to test the existence of muscular irritability in the air-tubes ; and if such were present, to deter- mine its character, and the circumstances or influences which could affect or disturb it. The experiments were performed at the London University College, and in several of them I was kindly assisted by Professor Sharpey, Mr. James Blake, Dr. Davison, and several of my pupils, especially Messrs. Blom- field, Carlill, Parkes and Jos. King. In most of the experiments I made use of Poiseuille’s hemadynamometer, which is a tube bent like an inverted si- phon, containing a coloured fluid; the short limb of this tube, furnished with stop-cocks, being adapted to the windpipe or one of its branches, the column of fluid within would be readily moved by any contraction of the air-tubes or lungs, causing pres- sure on the air in it: and the rise or fall of this fluid was mea- sured by a scale divided into inches and tenths. 1. A dog was killed by pithing. The chest being imme- diately opened, the lungs collapsed completely. They were taken out with a part of the trachea, which was then tied to the brass tube of the hemadynamometer (or as I shall call it, the dynameter) ; on completing the communication by turning the stop-cock, the fluid in the tube oscillated several times to the amount of about one fourth of an inch. On passing a galvanic current, from a trough of thirty three-inch plates, from the margin of the lungs to the brass tube in the trachea, the fluid rose quickly, but gradually, nearly two inches; it sunk speedily on breaking contact ; again rose on repeating it; but fell slowly when the contact was continued for some seconds. When the current was passed only through a single lobe, the rise was still distinct, amounting to three or four tenths of an inch. The rise was repeatedly produced, but to a diminishing extent, and after two or three minutes the effect seemed to be exhausted. 2, The preceding experiment was repeated with eight dogs of various sizes, with similar results. The rise of the fluid co- lumn caused by galvanising the whole lung amounted at first to from 14 to 2} inches, but afterwards gradually diminished. If the current was passed continuously for some length of time, the fluid in the tube fell, and could not be raised by the gal- vanism for a minute or two after. It was found also that inflating the lungs impaired the effect of the current. On repeating the ON THE PHYSIOLOGY OF THE LUNGS AND AIR-TUBES. 413 experiments further, it was found that the irritability was only exhausted for a time; and on waiting two or three minutes between each application of the galvanism, the liquid was raised again and again for upwards of an hour; at first to the extent of one or two inches, but afterwards to a gradually diminishing extent, until all effect ceased. So, too, although no effect ensued immediately after inflating the lung, yet on waiting a minute or two the contraction took place, only diminished in degree by the compressed state of the air, which required more contractile force to move it. The fall on interrupting the current was pretty rapid, the fluid recovering its level in from ten to twenty seconds. 3. Several trials were made to compare the contractility of the smaller and the larger bronchial tubes respectively. When the galvanism was passed along only the margins of the lobes, scarcely any contraction ensued. When passed from the margin to the middle of the lobes the column rose two or three tenths and soon subsided. When passed across a lobe, at right angles with the chief tubes, the rise was from two to four tenths. But the greatest amount of contraction was caused by passing the current from the margins of the lobes to the larger tubes, or across the direction of these tubes, especially near the bifurca- tion of the trachea. The rise produced by galvanising these portions could be also renewed at intervals for a period much longer than in other parts. 4, The preceding experiments were all made on the lungs re- moved from the body immediately after death. I tried to obtain the same results with the lungs in the body; but it was not easy to galvanise the lungs without affecting the muscles of the chest, the contractions of which might interfere with the results. The expedient adopted was, immediately on the death of the animal to adapt the dynameter to the trachea; then to open the chest and break back the ribs, and having separated the lungs, to pass between them and the walls of the chest a piece of oiled cloth, and then to apply the galvanic wires to different parts of the lungs. This experiment gave less distinct results than when the lungs were removed from the body: It was repeated five times ; but it will be sufficient to describe one instance in which the galvanism was tried on the par vagum as well as on the lungs themselves. A large dog was pithed, and the dyna- meter adapted to the trachea. On opening the chest, the col- lapse of the lungs caused the fluid to rise three inches. The vagi being exposed in the neck, one was pinched ; it caused no effect on the dynameter. The other vagus was then galvanised across and along a portion of it; no effect followed in the bronchial 414 REPORT—-1840. tubes, but the cesophagus was strongly convulsed. The nerve was then separated and the galvanism passed through it to the base of the lung; this raised the dynameter only a tenth. On passing the current from the base of the lungs to the trachea the column rose more than an inch, sinking again rapidly on the withdrawal of the galvanism. 5. In all the preceding experiments the animals were killed by pithing: other modes of death were afterwards tried. A rabbit was killed by a blow on the back of theneck. The lungs and trachea being cut out, moderately inflated and galvan- ised, little effect was produced in the first ten minutes, but the column had gradually sunk about three tenths of an inch, after this the galvanism repeatedly raised it two tenths. 6. A large dog was bled to death by dividing the jugular veins. Death was preceded by very deep and rare breathing ; the heart beat a few pulses after respiration and sensibility had ceased. On adapting the dynameter to the trachea, the column was stationary ; on opening the abdomen it sunk half an inch, On opening the chest it rose five inches. After taking the lungs out of the body, galvanism failed to’ raise the column ; but this failure probably arose from the tube being obstructed with viscid mucus ; for on applying the wires to the bifurcation of the trachea the tubes were seen to contract distinctly. This suggested another mode of observation which had been dis- trusted before, as liable to error. The lungs were cut by sharp scissors at right angles to the chief air-tubes ; the open sections being galvanised contracted to half, and in some instances to less than half their former diameter. To ensure accuracy, the gaping ends, as soon as cut, were measured by compasses or tubes of similar size. The contraction was most distinct in the middle-sized tubes, and those of the size of a crow-quill. One of these closed completely. These results were obtained for half an hour after death, and long after the heart had lost its irritability. 7. A large greyhound was killed by pithing. The lungs being removed, one lobe was tried by galvanism and the dyna- meter, with the usual results. A large bronchus of another lobe was then cut open longitudinally, laid flat and then galvanised. It became hollow and contracted a third, and at one part half its diameter. The divided ends of other bronchi also contracted to less than half. In one instance, when the interior of a large bronchus was galvanised, bloody mucus was expelled from one of its branches across which the current passed. 8. A bullock’s lung was experimented on about twenty mi- mutes after death, which was caused as usual by a blow on the ON THE PHYSIOLOGY OF THE LUNGS AND AIR-TUBES. 415 head and dividing the vessels of the neck. The bronchi were full of frothy mucus, and on touching any of them with the galvanic wires, this froth was exuded from them. Their mea- sured size also shrunk under the same influence. 9. The same results were obtained with the lungs of a calf, half an hour after death (by bleeding and pithing). A small lobe of the lung when galvanised raised the dynameter three tenths. 10. Two years ago I observed in the lungs of a horse just killed by knacking, that the divided ends of the bronchi slowly contracted on being irritated with a scalpel; but as no mea- surement was used, and as those which were not thus irritated also contracted, only more slowly, I did not then consider the result conclusive. It may, however, now be arranged among other facts of the same kind. 11. In many instances which I need not now detail, I tried to excite the contraction of the air-tubes by chemical irritants, such as salt and diluted ammonia. I succeeded with the divided ends of the tubes ; but with the dynameter it was more difficult, from the difficulty of introducing the irritant without mechani- cally affecting the column, and also from the irritant causing the formation of mucous viscid froth, which obstructed the tubes. The following was the most successful of these at- tempts. 12. A dog was pithed and the lungs exposed by breaking back the ribs. To the trachea was tied a tube with two branches furnished with stop-cocks. One branch communicated with the dynameter; through the other the lungs were to be in- flated to give the tubes their full diameter. The irritating fluid was poured into the tube of the dynameter in quantity sufficient that some might drop into. the trachea on blowing into the upper end of the tube. The lungs being moderately inflated, the stop-cock of the dynameter was turned, when the column rose three inches. The column was then depressed by blowing with the mouth till some dropped into the windpipe. On with- drawing the mouth the column was driven up three tenths above its former level, and slowly rose two tenths more. This rise could only be ascribed to the contraction of the tubes excited by the irritating liquid in them. By changing the position of the lung, several sudden starts of one or two tenths repeatedly occurred, probably caused by the irritating fluid coming in con- tact with more tubes. But all these movements were much im- peded by the viscid froth which collected in the bronchi. The lungs being suffered to collapse, the column sank to a level. After a while it sunk further two inches below the level; being 416 REPORT—1840. probably thus drawn down by the re-expansion of the cartilagi- nous rings of the tubes, now set free by the relaxation of their contractile fibres. On cutting into the lung the trachea and bronchi were found unusually open, and filled with tenacious froth. In another instance in which this experiment was re- peated, the rise after the injection of diluted ammonia amounted to 12 inch. 13. The experiment was repeated with saturated solution of common salt, with similar results. 14. The following experiment illustrates several of the same points; and further shows the character of the sensibility in different parts of the air-passages. Subject, a large Newfound- land dog. The trachea was exposed and divided below the cri- coid cartilage. It was then held out by a hook. On being ir- ritated by a scalpel, the membranous portion gradually con- tracted until the ends of the cartilaginous rings met. The contraction was somewhat increased by galvanism. The appli- cation of salt caused no further effect. None of these irritations excited cough or sign of uneasiness ;_ but on passing the finger upwards to the larynx, violent expiratory efforts were excited, and the glottis very forcibly closed on the finger. The expira- tory efforts forced a little bloody mucus from the trachea. A scalpel was introduced into the trachea as far as its bifurcation, and scraped against the membrane. No cough followed for some time ; but on repeating the experiment about a minute after, cough ensued, and increased on subsequent trials. The salt ap- plied caused a secretion of bloody mucus. The blood-vessels in the upper part of the chest were now cut into, when the rare deep inspirations preceding death by hemorrhage succeeded. The heart continued to beat several seconds after the cessation of respiration. The bronchi exhibited full indications of con- tractility on the application of galvanism, or of salt, or ammo- nia. The upper part of the trachea, which had during life been irritated with salt and galvanism, was now found quite expanded, the portions lower down were half-expanded. Both contracted slightly on being galvanised, and completely on dividing their cartilaginous rings. Having satisfactorily proved the existence of irritable con- tractility in the air-tubes, I next proceeded to try how this would be influenced by various medicinal agents which we are in the habit of using in various diseases of the organs of respiration. 15. A rabbit was poisoned by dropping some strong hydro- cyanic acid intoitsmouth. In thirty seconds it was seized with convulsive and gasping breathing, and opisthotonic spasms, and died in ten seconds more. Galvanism produced no results with ON THE PHYSIOLOGY OF THE LUNGS AND AIR-TUBES. 417 the dynameter for the first five minutes ; but after this it took effect, and raised the column two tenths; and in a quarter of an hour four tenths. These effects gradually diminished, and ceased in half an hour. 16. About ten grains of extract of belladonna*, mixed with water, were injected into the jugular vein of a rabbit. In fifteen seconds, gasping with slight convulsions, and death in less than a minute. On opening the abdomen the heart was seen through the diaphragm acting quickly. The dynameter being adapted to the trachea, the chest was opened, when the column imme- diately rose two inches, and slowly an inch more, when it re- - mained stationary. Galvanism produced no effect for several’ minutes, and then a scarcely perceptible rise, which could not be re-induced, although the experiment was continued an hour. 17. A dog was poisoned by mouth with hydrocyanic acid. He fell down howling in a minute and a half, and ceased to breathe in about halfaminute more. Heart beat strongly when the chest was opened. Galvanism raised the column of the dy- nameter two inches, and a similar but decreasing effect was ob- tained at times for half an hour. The same differences were observed in the contractility of different parts, as after death by pithing. The cut ends of the tubes continued to contract on being galvanised half an hour after death. 18. About twenty drops of strong hydrocyanic acid were in- jected into the carotid artery of an ass about six months old. It immediately caused the breathing to become very deep and rare; but the effect passing off in about ten minutes, nearly a drachm more was injected. The deep convulsive breathing re- turned, with tetanic rigidity of the trunk and loud groaning. The breathing became very rare, whilst the heart beat violently with a double second sound. Death ensued about. three mi- nutes after the second injection. A small lobe of the lung when galvanised repeatedly raised the column three tenths. Sections of tubes in other parts contracted distinctly on being galvanised, but to a less extent than in the dog. Contractile motion was distinctly seen on cutting a cartilaginous ring of the trachea, and then galvanising the membranous portion at the back. 19. About ten grains of extract of belladonna mixed with water, were injected into the right jugular vein of a large dog. Pupils began to dilate in fifteen seconds, and breathing more and more deep and laborious, accompanied with convulsive starts and howling. The breathing ceased and the eye became insensible two minutes after the injection. The integuments of * This and other extracts used were obtained from Mr. Squire, Chemist to the Queen. : ' 1840. 25 418 REPORT—1840. the chest being then divided, some dark blood flowed in jets from the cut vessels ; the animal then made six or seven deep gasps, during which the heart beat more strongly, and the eye slightly winked on being touched. This partial restoration was probably caused by the bleeding. On taking out the lungs scarcely a trace of contractility could be detected in them by the dyname- ter, and the cut ends of the tubes shrunk but little on being gal- vanised. The trachea was quite relaxed, and scarcely any approximation of the cartilages was produced by galvanism. The arteries also were less contracted than usual. 20. About thirty grains of extract of stramonium were in- jected into the cellular tissue of the neck of a dog. The breath- ing soon became very quick, laborious, and occasionally ster- torous. Lower extremities very weak and dragged, as if para- lysed. Pupil extremely dilated ; but the sensibility of the eye and consciousness of sounds remained till near death, which took place twenty-five minutes after the injection. The heart was found motionless and unirritable, its right cavities and the veins much gorged with blood ; left cavities and arteries empty. On cutting and galvanising the bronchi, very. little contraction was perceived, and none with the dynameter. Csophagus and intestines still irritable. 21. Two grains of nitrate of strychnia, dissolved, were injected into the carotid of a large dog. In less than four seconds te- tanic convulsions, which continued a minute. The eye became insensible in half a minute. On opening the chest the heart was found motionless and unirritable; right cavities and veins enormously distended. Lungs being taken out and galvanized, at first raised the dynameter two tenths, but not afterwards. Voluntary muscles relaxed after death, and were less irritable than usual. 22. A solution of four grains of nitrate of strychnia was in- jected into the jugular vein of a donkey two months old. In fifteen seconds spasms and tetanic stiffness. Eye soon ceased to wink on being touched. Spasms of neck and back continued for more than a minute On opening the chest the heart was still beating, the veins and right side much distended. The air- tubes gave no sign of contractility with galvanism, although the experiment was continued for some time. 23. Wishing to compare the contractility of the bronchi with that of the arteries, 1 made the following experiment. Imme- diately after the death of the subject of the preceding experi- ment, ligatures were applied to the top of the descending aorta and to the left common iliac, and adynameter to the right com- mon iliac, some carbonate of soda and water being first injected ON THE PHYSIOLOGY OF THE LUNGS AND AIR-TUBES. 419 to prevent the blood from coagulating. The aorta was then gal- vanised, and the column immediately rose gradually two inches. On removing the wires, it still rose a few seconds, and then sunk progressively, After it had sunk two inches, the galvanism again raised it two tenths, but no more. This was about twenty-five minutes after death. The auricles continued to be excitable by galvanism more than half an hour after death, the contraction of one auricle being followed by that of the other. In this and another donkey, I had proved that the arteries contracted during life on the application of the galvanic, as well as of ¢hemical and mechanical stimuli. 24. Some tincture of Lobelia eflata, much concentrated by evaporation, was injected into the jugular vein of a dog. There were symptoms of uneasiness for a few minutes, but no further effect. A fluid extract obtained by evaporating Ziss. solution of bimeconate of morphia (Squire) was then injected. In twelve seconds, peculiar convulsive starts and some general tremor, with laborious breathing, followed by death in about a minute and. ahalf. Heart was beating when the chest wasopened. Single lobes of the lungs being galvanised raised the dynameter co- lumn slightly, not more than a tenth. On cutting the lung, the sections contracted more distinctly, but much less so than in other cases. Trachea expanded. 25. About half a drachm of extract of conium mixed with water was injected into the external jugular vein of a dog. In twelve seconds the breathing became very quick and laborious, and in a minute the animal was dead. Bronchi not contractile as tested by the dynameter, and less than usual on galvanising cut portions. The trachea was already contracted so much that the ends of the cartilaginous rings were in contact. The heart was still irritable. I trust that many of the results of the preceding experiments are sufficiently evident without further comment. Almost all of them prove that the air-tubes are endowed with irritable contractility, excitable by electric, chemical, and me-: 2 aa stimuli, and they possess also tonic contractility (10, 25). The contractility is manifest in all portions of the air-tubes (3, 6, 7, 12, &c.). In the trachea and larger bronchi it is anta- gonised by the elasticity of the cartilaginous rings (12, 14). It does not appear to exist in the vesicular terminations of the air-tubes (3). This contractility resembles that of the intestines or arteries more than that of voluntary muscles, the oesophagus, or heart, the contractions and relaxations being more gradual than those 2E2 420 : REPORT—1840. of the latter, but less tardy than those of the former. (1, 2, 17, Sh Sec!) The irritability of the bronchial muscles is soon exhausted by the action of a stimulus (1, 2, 5, 12, &c.); and may in some degree be restored by rest, even when the lung is removed from the body for an hour or more (2, 3, 6). But when the stimula- tion is long continued, as by intense irritation of the mucous membrane during life, the irritability is not restored by rest, and the tonic contractility is also impaired (14). The contractility of the air-tubes seems to be much influenced by the mode of death ; having been for a time suspended after death by a blow on the back of the neck (5), and in one instance after death by pithing, and hemorrhage. Inflation of the lung also in some way suspends it for a while (2). Several vegetable poisons impair or destroy this contractility. Extracts of stramonium and belladonna produced this effect most completely (16, 19, 20). (Their superior efficacy in spas- modic asthma has been long known.) Strychnia, conium, and morphia also impair this property considerably (21, 22, 24, 25). Hydrocyanic acid, on the other hand, does not in any consider- able degree impair it (15, 17, 18). These poisons and different modes of death do not act on the irritability of the bronchial tubes in the same degree as they do on that of the heart and other contractile tissues, (22, 23, 24, 25,) and they do not seem to act always equally on the irritable and on the tonic contractility of these tubes (25). ; The bronchial fibres seem to be excited more by direct sti- mulation than by any influence conveyed through the nerves of the lungs; for mechanical and galvanic irritation of the vagi had no effect on them ; and passing acurrent through the nerves to the lungs caused much less contraction than passing it through the trachea (4). I am well aware that these, and many other subjects connected with them, deserve a fuller investigation, and I have to regret that my engagements have prevented me from prosecuting them further. Such as they are I submit them to the consideration of the Section without dwelling on their practical bearings. Cuarues J. B. Wituiams, M.D., F.R.S., Professor of the Principles and Practice of Medicine, and Physician to the Hospital, London Univer- sity College. Holles Street, Cavendish Square, Sept. 15th, 1840. 421 Report of the Committee appointed to try Experiments on the Preservation of Animal and Vegetable Substances. Drawn up by The Rev. J.S. HEnstow, F.L.S., Professor of Botany in the University of Cambridge. Tue Committee have hitherto directed their attention entirely to the investigation of the preserving properties of certain ma- terials when applied separately, either in saturated solutions, or in different degrees of concentration. A set of glass jars, of uniform dimensions (6 inches by 14), was procured, and saturated solutions of the substances to be tried were prepared. Similar solutions were also diluted with an equal quantity of water, and with double the quantity of water, and separate preparations were made of animal and vegetable substances to the amount of 178. These were left in the Mu- seum of the Botanic Garden at Cambridge, and have been in- spected at intervals of one and two years. It is intended that all should remain where they now stand, whether the results may prove satisfactory or not; as, possibly, some facts may be elicited worth noticing, respecting the different manner in which organized substances are decomposed when placed in a variety of mixtures which do not preserve them. The next step which the Committee propose taking, will be to mix those solutions which seem to them most likely to suc- ceed, in various proportions ; and to prepare a fresh set of ob- jects in these mixtures, which will be placed with the former. This, indeed, ought to have been done some months ago, but circumstances have prevented the Committee from carrying this part of their plan into effect. No very satisfactory conclusions can be expected to result from these experiments until they shall have stood the test of a greater length of time than has yet elapsed since they were commenced. An account of the re- sults hitherto obtained will be of service in directing the re- searches of any who may be disposed to follow up the inquiry, and the Committee will be glad to receive the suggestions or aid of any members of the Section who may be disposed to co- operate with them. Ist. Results obtained with Animal Substances.—Three salts of potash, the sub-carbonate, the bi-carbonate, and the arse- niate, have hitherto yielded the most satisfactory results, and of these more especially the sub-carbonate. Although the bi- carbonate has preserved the objects immersed in it, the liquid has become clouded with flocculent matter. A similar formation of flocculent matter occurs in some of the other solutions, but has not yet been minutely examined. These three salts are effective in each of the three states of concentration em- ployed, but perhaps the effect is best where the solution is half of the saturated solution and half of water. 422 REPORT—1840. The next best to these three, are the sulphate of zinc, the muriate of magnesia, and arsenious acid. The following also possess tolerably fair preserving properties, but are by no means so good as those already mentioned. They may be recommended in cases of emergency, as temporary ex- pedients, and some of them will probably prove more efficient when used in combination with others, than when employed singly: sulphate of magnesia, sulphate of potash and alumina, (common alum,) sulphate of zinc, muriate of ammonia, sulphate of potash. It is well known that corrosive sublimate is a per- fect preservative of animal substances, but this salt renders the flesh so very hard, that singly it is unsuited to the purposes of natural history. Added in small proportions to other solutions, which render the objects too soft, it will probably be tound of essential service; as well also in preventing the formation of the flocculent matter which occurs in several of them. Prepared naphtha, in the proportion of one part naphtha to seven of water, produces a favourable result, but when used more highly concentrated the specimens are rendered tough. The rapid evaporation of this substance is an objection to its use. The effects produced by oxalic acid, and acetic acid, are pe- culiar ; they seem to have decomposed the skin and cellular membrane of two small fish immersed in them, but to have left the muscle untouched. The consequence has been that these animals have fallen to pieces, but the separate fragments are well preserved, more especially in the acetic acid. -A few drops of kreosote added to water preserves the objects, but they become stained of a dark brown. The following sub- stances appear to be wholly unfit for the purpose, and no further trial need be made with them: carb. ammonia, chloride of potash, muriate of barytes, muriate of lime, nitrate of ammonia, nitrate of strontian, nitrate of barytes, nitrate of soda, nitrate of ammonia and magnesia, phosphate of soda, sulphate of soda, sulphate of pot- ash, sulphate of iron, sulphate of copper, rough pyroligneous acid. 2nd. Results obtained with Vegetable Substances.—The suc- cess obtained with vegetable substances has been very slight. Spe- cimens were immersed in each solution, as in the case of the ani- mal substances. None of the salts seem likely to turn out fa- vourably in simple solution, unless it may be the sub-carbonate and bi-earbonate of potash. In naphtha and acetic acid the spe- cimens are preserved, but in the latter they lose their colour and assume a reddish tinge. P.S. It does not appear from the memoranda that the carbo- nates of soda are among the list of substances tried ; but I have found that the preserving properties of the common soda of the shops are decidedly good on animal substances. J. S. Henstow. 423 PROVISIONAL REPORTS, AND NOTICES OF PROGRESS IN SPECIAL RESEARCHES ENTRUSTED TO COMMIT- TEES AND INDIVIDUALS. MATHEMATICS AND PHYSICS. Statement by G. B. Arry, Esq., Astron. Royal, relating to the progress of the Reductions of the Greenwich Lunar and Planetary Observations, undertaken at the recommenda- tion of the British Association; and to the state of the Funds appropriated to these works. A RESOLUTION of the General Committee of the British Asso- ciation, recommending to the Government the reduction of all the observations of the Planets made at Greenwich from the time of Bradley, was passed at Cambridge on June 28, 1833, and a deputation was appointed to wait on Lord Althorp, in order to present this recommendation, and to request that the sum of 5002. should be placed in my hands for these reductions. The sum named was fixed on wholly at random, and without any sort of accurate estimate, of which the operations did not seem to admit. Lord Althorp’s answer assenting to the grant was dated July 25, 1833. It was understood verbally from his Lordship’s private secretary (Mr. Drummond), that more money would be granted if required. The whole sum of 5002. has been advanced to me by the fol- lowing payments. 1836—Jan. 8 : 3 .£122 17 9 1887—May 27. , MD eB B 1838—Feb. 24 . : 4 ADC doe Total . . £500 0 0 The last payment is subsequent to the later arrangement cee to lunar reductions, of which I now proceed to speak. In the Meeting of the Association at Liverpool in 1837, the General Committee recommended that the Observations of the Moon should be reduced, and appointed a deputation to wait on Mr. Spring Rice, and to convey this recommendation. The 424 REPORT—1840. deputation accordingly attended at the Exchequer in the winter of that year, and made the application, naming the sum of 2000/. as necessary, but stating in the formal memorial that the expense might probably exceed 20007. And on December 26 of the same year, in writing to Mr. Spring Rice on this matter, I recommended that the accounts for planetary reductions and lunar reductions should be incorporated, as in pursuing the work in the most advantageous way, it was wholly impossible to keep the operations separate. The Lords of the Treasury assented to this application, and directed that 600/. should be advanced per annum, till the 20002. should be expended. In the applications made by me to the Lords of the Treasury on April 13, 1839, and April 18, 1840, I stated fully that the money last granted (for the lunar reductions) had been em- ployed in part on the planetary reductions. The advances made to me from the Treasury are the follow- ing :— 1838—June 13 : ‘ . £600 0 0 1839—May 31 : : +13 GO0,cO560 1840—April 27... 4 . 600 0 O Total . . £1800 0 0 Leaving still payable to me 200 ie 0 0 from the original grant s_ And on Sept. 4, 1840, I had in 563 0 0 hand about : ‘ : I have, therefore, at my com- "63 0 0 mand . t : ‘ : This sum may be expected to last a short time beyond the next meeting of the Association ; but it would not, in my opi- * nion, be prudent to defer proceedings for increasing the sum till that time. The state of the reductions is nearly as follows :— Planets. The transits and right ascensions of all the planets are nearly all completed in duplicate, compared, examined by differences, and in other ways. The polar distances are entirely reduced in duplicate, com- pared, examined, &c., for all the planets, except an inconsider- able part of the observations of Uranus (probably finished by PROVISIONAL RHPORTS, AND NOTICES. 425 this time), and the observations of the small planets, for which the distance necessary for the parallaxes is wanting. The computation of geocentric longitude and latitude from A and NPD is finished in duplicate for Mercury, Venus and Mars, examined and compared. Jupiter is advanced (proba- bly now finished), and Saturn has been commenced (probably now far advanced). The computation of the Tabular Heliocentric places of all the planets, except the small ones, is finished in duplicate and examined. The computation of the Tabular Geocentric places is finish- ed for all the large planets, except the application of aberration to Saturn and Uranus, and a few observations of Jupiter. The reduced observed places have been confronted with the reduced tabular places for Mercury and Mars, and thoroughly examined by myself; and these are, in all important respects, ready for printing. Those for Venus have also been computed, but not yet thoroughly examined by me. The whole of this department will, inno long time, be ready for press. The only new work to be done upon it is the cal- culation of the co-efficients of tellurian and planetary heliocentric errors, which must be conceived to form the geocentric er- rors. Lunar Observations. The whole of the imperfect transits are completed; and this has been a very laborious operation. The apparent A of the stars for the clock-errors are formed, and are ready for application to the investigation of the moon’s right ascension, but are not yet applied. No other work is yet done for the lunar observations, though the books, &c. are prepared for many parts of the work. . G. B. Airy. To the Committee of the Physical and Mathematical Section of the British Association. Tue Report of the Committee on the Form of Vessels was read to the Meeting ; but in consequence of the extensive ta- bles and drawings required for its illustration, it has not yet been completed for publication. THE Committee appointed to superintend the extension of the Royal Astronomical Society's Catalogue of Stars, report— That the work is in considerable progress, and that it will probably be completed before the next meeting of the British Association in 1841. They further report, that 360/. have been: 426 REPORT—1840. already paid for computations, and about 701. for printing and other expenses, making a total of about 430/. out of the original grant of 5007. As this balance of 70/. will not be sufficient to complete the work, the Committee request that it may be ex- tended to 150/., which, they hope, will meet every expense. Tue Committee appointed to superintend the reduction of the stars in the Histoire Céleste, report— That about 33,000 stars have been already reduced, the cost of which has been 412/., exclusive of about 52/. for printing skeleton forms for the use of the computer. They further re- port, that there are about 16,000 more stars to be reduced, the cost of which will be about 200/. more. As the original grant will not cover the whole of this expense, (there being only about 351. remaining out of that grant,) the Committee suggest the propriety of extending the grant, for the ensuing year, to the 200/. above mentioned, which, they trust, will complete the work. Francis BAILy. August 25, 1840. Second Report of a Committee of the British Association, con- sisting of Sir J. HERscue., Prof. WHEwE.L and Mr. Baty, for revising the nomenclature of the Stars, appointed at Newcastle, 1838. Tue revision of the northern hemisphere and the constellations visible in Europe has been continued by Mr. Baily, by carefully tracing the just and most authentic limits of the existing and recognised constellations, and by a careful examination of the several stars, in the course of which many singular instances of confusion and error in naming and placing have been detected. This process, which involves an investigation of the history of each star, and of the designations it has received from each of its observers, and in the several catalogues in which it occurs, is nearly complete, and may be considered as clearing the ground for a systematic nomenclature of the northern stars, as well as for an effective table of synonyms of each star. In the southern hemisphere, or rather in those constellations which are only visible to an observer in that hemisphere, Sir John Herschel has continued and nearly completed a chart of those stars only, and of all those stars which are distinctly visi- ble to the naked eye in a clear night, in which chart each star is represented of its true magnitude, according to a scale, in which the total interval from the stars of the first magnitude to the lowest inserted, in place of six degrees, is made to consist PROVISIONAL REPORTS, AND NOTICES. A27 of eighteen, so as to subdivide each magnitude into three. The final assignment of these magnitudes, resting on the collation and inter-comparison of an extensive series of observations made for that express purpose with the naked eye, occasionally assisted by a common opera-glass, has been a work of much time and labour, and is not yet quite completed. Nor till this is accomplished, can any further progress be made in the re- arrangement of the southern constellations, which, at present, are in a state of great confusion. A small part only of the grant of 50/., devoted by the Asso- ciation to this object, has been expended; but the whole will, no doubt, be required ; and your Committee, therefore, recom- mend its continuance. Signed, on the part of the Committee, | J. F. W. Herscuet. Report of a Committee for the reduction of Lacaille’s Stars in the Celum Australe Stelliferum. Tue reductions of all the stars in Lacaille’s Celum Australe Stelliferum are finished, and Mr. Henderson’s assistant is at present arranging the results in the form of a catalogue, which, however, could not be completed in time for this meeting. The completed portion, so far as finished, has been transmitted to Mr. Baily, to be used in the construction of the new catalogue of the Astronomical Society. No money has been spent during ce year; but, of course, a renewal of the grant will be desira- ble. _ Signed, for the Committee, J. F. W. HerscueEt. Report of the Committee, consisting of Sir J. Herscurt, Pro- fessor Wuewe ., Professor Peacock, Professor Luoyp, and Major Sasine, appointed to superintend the scientific co- operation of the Association in the Researches relative to Terrestrial Magnetism. In consequence of the measures adopted as detailed in the last report of this Committee, a very extensive system of magnetical corresponding observations has been organized, embracing be- tween thirty and forty stations in various and remote parts of the globe, provided with magnetometers, and every requisite instrument, and with observers, carefully selected, and compe- tent to carry out at most, if not in all the stations, a complete series of two hourly observations, day and night, during the whole period of their remaining in activity, together with monthly term-observations, at intervals of two minutes and a 428 REPORT—1840. half. Of these observatories, that at Dublin, placed under the immediate superintendence of Professor Lloyd, has been equipped and provided for by the praiseworthy liberality and public spirit of the University of that metropolis. Those at Toronto, the Cape of Good Hope, St. Helena and Van Die- men’s Land, as also the two itinerant observatories of the Antarctic expedition, by the British Government; those of Madras, Simla, Singapore and Bombay, by the Honourable East India Company; to which are to be added ten stations in Kuropean and Asiatic Russia, and one at Pekin, established by Russia; two by Austria at Prague and Milan; two by the Universities of Philadelphia and Cambridge in the United States ; one by the French Government at Algiers; one by the Prussian at Breslau; one by the Bavarian at Munich; one by the Spanish at Cadiz; one by the Belgian at Brussels; one by the Pacha of Egypt at Cairo; one by the Rajah of Travan- core at Trevandrum in India; and one by the King of Oude at Lucknow. In addition to this list, it has recently also been determined by the British Government (at the instance of the Royal So- ciety) to provide for the performance of a series of correspond- ing observations, both magnetic and meteorological, at the Royal Observatory at Greenwich, under the able superintend- ence of the Astronomer Royal. In Norway, negotiations, in which M. Hansteen has taken an especial interest, have been for some time carrying on for establishing an observatory of a similar description at Hammerfest. A great number of mag- netic and other instruments available for this service, it ap- pears, have been left at Kaafiord by M. Gaymard, acting for the “Commission Scientifique du Nord,” under the directions of the French Ministry of the Marine, all which instruments, through the efficient intervention of M. Arago, it is under- stood, will be placed at the disposal of the observer or observers who may be appointed to conduct the observations. To com- plete the establishment, however, certain instruments, as well as registry-books, &c. are still requisite. ‘The Council of the Royal Society have undertaken to supply these from the Wol- laston Donation Fund. As regards the magnetic observatory at Breslau, under the direction of M. Boguslawski, your Committee have to report, that in order to secure the establishment of that station, and to place it on an equal footing with the rest, certain instru- ments, &c. required to be provided, for which no funds existed, or could be made available on the spot, viz. a bifilar and a vertical-force magnetometer, with the requisite reading-tele- PROVISIONAL REPORTS, AND NOTICES. 429 scope, and a set of registry-books. As, owing to the actual circumstances of that observatory, there appeared no prospect of these requisites being otherwise supplied,—as the station appeared to your Committee a desirable one, and as M. Boguslawski was willing and desirous to lend his aid to this great combined operation, by taking on himself the laborious duty of conducting the observations,—your Committee con- ceived, that although possibly transgressing in some degree the strict wording of their powers, they were only acting up to their spirit in devoting a portion (185/.) of the funds placed at ‘their disposal, to supplying them at the expense of the Asso- ciation. Unwilling to claim any privilege, or establish any precedent for the smallest deviation from the strict literal in- terpretation of a money grant, your Committee suggest to the meeting the propriety of ratifying, by an express act of recog- nition, the application of the above-mentioned sum. A letter from M. Boguslawski, dated the 22nd July, 1840, announces the safe arrival of the instruments and books in question, and the consequent complete state of instrumental equipment of the Breslau Observatory, expressing at the same time his sincere thanks for the assistance accorded him. By returns from the several stations authorized by the British Government, so far as yet received, it appears that the observa- tories at the Cape and at St. Helena might be expected to be complete, and ready for reception of the instruments in July. From Van Diemen’s Land no accounts have yet been received. At Toronto, where the greatest delays and difficulties were to be expected, and have been experienced, the observatory was so far advanced at the date of Mr. Riddell’s last communica- tion, as to leave no doubt of its completion in time for the regu- lar observation of the August term. Meanwhile, in this, as at the other stations, all observations practicable under the actual circumstances of each, are made and regularly forwarded. And here your Committee would especially call attention to the extremely remarkable phenomena exhibited at Toronto on the 29th and 30th May, when, by great good fortune, a most superb Aurora appeared at the very time of the term-ob- servations.* ‘The phenomena of this Aurora (which was re- markable for the extent and frequency of the pulsating waves, alluded to in that part of the report above cited, p. 47, re- lating to this subject,) are very minutely and scientifically described by Mr. Riddell. But what renders the occurrence particularly interesting is the fact, that during the whole time of the visible appearance of this Aurora, on the night from * See table of the terms, Report of the Council of the Royal Society, p. 31. 430 REPORT—1840. the 29th to the 30th, as well as for some hours previous, while it might be presumed to be in progress, though ef- faced by daylight, all the three magnetical instruments were thrown into a state of continual and very extraordinary dis- turbance. In fact, at 64 25™ in the morning of the 29th, the disturbance in the magnetic declination during a single minute of time carried the needle over 10! of arc; and during the most brilliant part of the evening’s display (from 35 25™ Gott. M. T. to 45 35™,) the disturbances were such as to throw the scales of both the vertical- and horizontal-force magnetome- ters out of the field of view, and to produce a total change of declination amounting to 1° 59’. It should also be remarked, that the greatest and most sudden disturbances were coinci- dent with great bursts of the auroral streamers. The corre- spondence, or want of correspondence, of these deviations with the perturbations of the magnetic elements observed in Europe, and elsewhere, on the same day, cannot fail to prove of great interest. Should it fortunately have happened that Captain Ross has been able to observe. that term at Kerguelen’s Land, which is not very far from the antipodes of Toronto, an indi- cation will be afforded whether or not the electric streams pro- ducing the Aurora are to be regarded as diverging from one magnetic pole or region, and converging to another*. Your Committee cannot conclude this report without con- egratulating the Association, and the scientific world in general, on the extensive interest inspired, and the vast range of obser- vation consequently embraced by these operations, which, so far as any accounts have hitherto reached them, appear to be so far going on prosperously in all its parts, and to promise re- sults fully answerable to every expectation of its promoters. Neither would they feel justified in their own eyes, were they to omit expressing their deep and grateful sense of the inde- fatigable personal exertions of Major Sabine throughout the whole of its progress, both in carrying on a most voluminous correspondence, in ordering, arranging and dispatching in- * In reference to the Aurora which had been seen at Toronto in Upper Canada on the 29th of May, and to the magnetic perturbations by which its appearance had been accompanied, the Astronomer-Royat stated, that the term-day of the 29th and 30th of May had also been kept at the Royal Ob- servatory at Greenwich; that an Aurora was seen there also on the 29th, and that the disturbances of the declination magnetometer exceeded in amount any which had been observed there on previous occasions. Not having brought the observations with him, Mr. Airy could not state whether their comparison with the curves of the Toronto Observatory, which Major Sabine had laid be- fore the Section, would manifest an accordance between the disturbances at the igs stations, a point of the highest interest as to the nature and extent of these. PROVISIONAL REPORTS, AND NOTICES. 431 struments, and facilitating, by constant attention and activity, those innumerable details which are involved in a combination so extensive,—a combination which, but for those exertions, your Committee are fully of opinion, must have been greatly wanting in that unity of design and cooperation which now so eminently characterizes it. Signed, on the part of the Committee, J. F. W. Herscue. Referring to the magnetical observatory at Breslau, men- tioned in this report, Masor SaBine read the following letter from its director, M. von Boguslawski, received since the meeting had commenced. Breslau, September 7, 1840. My pear Sir,—I have the pleasure to inform you, that during the last magnetic term, viz. on the 28th and 29th August, I have made observations with the two magnetic instruments provided by the British Association. Not- withstanding the Michaelmas Term of our University has began, I have suc- ceeded in engaging and instructing a double number of observers sufficient to place them at the declination magnetometer in the magnetic cabinet, as well as at the horizontal, and at the vertical-force magnetometers in the great room of the observatory. The observations hitherto made can, however, only be con- sidered as observations of the magnetic variations, because there are several masses of iron fixed in the buildings. The prospect of obtaining a separate magnetic observatory being still distant, I feel myself highly indebted to Pro- fessor Lloyd for the assistance his paper ‘“‘ On the Mutual Action of Permanent Magnets, &c.” has afforded me. By these instructions I have succeeded in effecting what at first seemed to be impossible, namely, to place the declination magnetometer, the bifilar instrument, and the vertical-foree magnetometer, in the same room of the present magnetic cabinet, and to put them in equilibrium. How this is to be done by three small fixed subsidiary magnetic bars, I shall here- after explain to Professor Lloyd; and if he agrees with me, all three instru- ments will be placed in the magnetic cabinet at the next term. However, I shall use for a declination magnetometer the second magnetic bar received with the horizontal:force magnetometer, instead of the present bar of four pounds, in order to obtain small correction-constants. I shall then ex- pect with patience the establishment of a proper magnetic observatory, so as to begin to make absolute and daily observations. Please to communicate this in my name to the meeting of the British Association at Glasgow ; and have the kindness to express to them my regret, that on account of the necessary ar- rangements I have to make, I am prevented from accepting their honourable in- vitation, and assisting at their instructive assembly. (Signed) Henry von Bocustawskl, Major Edward Sabine. Major Sabine also presented to the Section, at the request of M. Kupffer, Director-general of the magnetical observatories of Russia, several copies of a report addressed by that gentle- man to the Imperial Academy of Sciences at St. Petersburg, entitled, “‘ Sur les Observatoires Magnétiques fondés par ordre des Gouvernemens d’Angleterre et de Russie, sur plusieurs 432 REPORT—1840. points de la surface terrestre.” In this report, the Russian observatories, acting on the same system of observation, both magnetical and meteor ological, as those of England, are enu- merated as follows :—‘ Ba science doit au gouv ernement Russe, et surtout 4 la protection puissante du ministre des finances, M. le Comte Cancrine, et a l’incessante activité du chef de l'état major du corps des ingénieurs des mines, M. le Général Tcheffkine, V’établissement des stations magnétiques’ sui- vantes : Stations. Directeurs. St. Pétersbourg M. Kurrrer, Directeur-Général. Cathérinebourg M. Roscuxorr, Barnaoll - - - - - - - M. Prance, 1* ¢ Ingénieursdes Mines. Nertchinskk - - - - - = M. Praneg, 2eme Kazan - - - - - - - - - M.Stimonorr,)] Directeurs des Observa- Nikolaieff - - - - - - - - M. Kwnorre, toires Astronomiques. Tiflis - - - - - M. Puitapetruine, Prof. au Gymnase. Sitka (Céte N. O. eS I’ Amérique) MM. Homann et Fwanorr. Helsingfors (Finland) - - - M. Nervanner, Prof. Extraor. a 1’Uni- versité. Pékin* (China) - - - - - - M. Gascuxevitscu, Membre de la Mis- sion Ecclesiastique.”’ The copies of M. Kupffer’s report were accompanied by a letter, expressing his regret that the necessary and pressing duty of instructing the directors of the observatories, in regard to the system to be pursued, prevented him from attending the meeting of the British Association at Glasgow, which he had otherwise intended to have done. Report on the reduction of Meteorological Observations made at the Equinoxes and Solstices, on the part of a Committee appointed by the British Association at Newcastle, consisting of Sir J. HERscHEL alone. Sir J. HerscukEt, referring to his report of last year for the reasons why the reduction of these observations was not imme- diately commenced, reports further, that the same reasons de- layed any effective commencement of the work until very lately ; but that, owing to several wanting series of observations having at length come to hand, so as to render the series for the years 1835-6-7-8 tolerably consecutive, at least, for several localities, your Committee considered it advisable to wait no longer, but proceed to work with the materials in hand. Accordingly, having cast the plan of operations for the comparison and projection of * A la station de Pékin nous aurons, si non autant d’observations que des autres stations, au moins les observations les plus importantes. PROVISIONAL REPORTS, AND NOTICES. 433 the barometric oscillations in those years, (to which, for the pre- sent, your Committee propose to limit their proceedings, til] it shall appear whether a further andmore complete comparison, in- cluding the thermometric changes, and especially the correspond- ence of the winds, seems likely to lead to any valuable conclu- sions,) tbe reduction, arrangement and projection of the several series of observations was confided to the able and zealous hands of W. R. Birt, Esq., who is now actively employed in the ope- ration, and who has enabled your Committee to lay before the meeting, as specimens of the mode of proceedings, the tabu- lation and projection of the observations made in the British Isles in the year 1836, which are accordingly submitted for in- spection. In the discussion of these observations it has been found ad- vantageous to divide the stations from which they have emanated into groups, according to geographical proximity, the chief of which are the group of the British Isles, that of the continent of Kurope and the North American, South African and Indian groups. Each of these groups is referred by applying the dif- ferences of longitude to the times of observation to a central station ; and the projected curves, in which the absciss# are the mean times at that station, and palmate the reduced barometric altitudes, exhibit at one view the correspondence or disagreement of the barometric movements for all the stations of the group. The numbers which serve for the projections are tabulated in the skeleton forms annexed, which appear well adapted for ge- neral adoption in such reductions, and of which, therefore, half a dozen blank copies are annexed as specimens for such members as may take an interest in the subject. The projection of these curves is the first step in the process of reduction contemplated ; and even in the very limited range afforded by the specimens now presented, affords ground for in- teresting remark. Thus, we see, that the march of the barcmeter in the only two Irish stations which have furnished observations (Markree and Limerick), while agreeing well with each other, differs most decidedly from its ‘corresponding march in all the English stations, which, on the other hand, offer a good corre- spondence inter se. A letter from Mr. Birt on this subject is annexed to the present report. It would be premature at present to enter fully into the de- tails of the further steps contemplated in these reductions, as they will be, of necessity, materially influenced by the aspect under which the subject shall present itself in its progress, and especially by the discussion of one or two of the most complete series, among which, thanks to American zeal and industry, the 1840. 2F 434 REPORT— 1840. group including the United States promises to be the most promi- nent. Only a very trifling sum (under two pounds) has been hitherto expended (for the printing, by Messrs. Stewart and Murray, of the skeleton forms) out of the original grant of 100/.; but the continuance of the grant will be required to meet the further re- quisite expenses. It is only justice to Mr. Birt to observe, that his part of the work appears to be executed with great care and judgment. (Signed) J. F. W. Herscue.. Mr. Birt’s Letter, alluded to in the above Report. Metropolitan L. and S. Institution, September 3, 1840. Dear S1r,—I herewith inclose the four sheets of curves mentioned in my last, also the tables of reduced barometric readings from which they are pro- jected. The curves of England and Ireland generally differ, in some cases con- siderably, with the exception of those observed in December 18386, on which oc- casion the similiarity between the Markree, Oxford, London, and Ashurst curves especially, as their apices occur about the same hour, is interesting. The occurrence of the apices of the Edinburgh, Halifax, and Oxford curves at later periods, and in the order here mentioned, appears to indicate a progres- sion of the barometric undulation from the north or north-east; and some of the remaining sheets alse indicate a progressive movement. I have not yet proceeded either to rounding off the curves, or to reading off the altitudes on the hour-lines. In the first instance, the undulations only which form the hourly observations assume a rising and falling in straight lines, will probably require a gentle rounding, so that the summit should pass through the point; for I see clearly, as you observed, that the points must not be interfered with, on account of the similar flexures in different curves. Do you consider any advantage would be gained from combining curves that are evidently similar, so that means of those similar curves may be obtained from similar altitudes above or below the mean-line, by bringing the apices and flex- ures on the same vertical ordinates, allowing for difference of longitude? The general dissimilarity of the curves obtained in Great Britain and Ireland, has suggested this to me also, that in future observations of the kind, it would be desirable to have the stations augmented, and, if possible, the observation of a complete elevation and depression at each. I hope you will receive the present sheets in good time for the meeting, And remain, dear Sir, Yours very respectfully, W. R. Birt. P.S.—In the Halifax curve of September, there are probably two errors. I have accordingly left the curve incomplete. The scale I have used is 1°5 of the larger divisions, equal -1 of an inch. Sir John F. W. Herschel. On the Temperature and Conducting Power of different Strata. By Professor Forbes. In this report, Professor Forbes gave the results of the ob- servations made at Edinburgh during the year 1839, upon PROVISIONAL REPORTS, AND NOTICES. 435 thermometers sunk to depths of 3, 6, 12 and 24 French feet into trap rock, pure loose sand, and sandstone. The details. for the years 1837 and 1838 were laid before the British Asso- ciation at Birmingham. Combining with these the observations for 1839, Professor Forbes exhibited the curves derived from the three years’ observations, and gave, in a tabular form, the results for the three years, as follows: Values of A (one of the constants in the formula used in con- necting the results*). In trap. In sand. In sandstone. For 1837 ...... 1°164 ..00. = EARN’ ssisan' L076 LeaO raters Lie eesere bel tc ween LPL 1889) -senc.¢ POBG. caccasi 12182 a..4.0 F040 Values of B (the other constant). In trap. In sand. In sandstone. For 1837 eoecee —'0545 eoccce —*0440 eoscce —°0316 1838 ...... —‘O641 ...... —*O0517 ...... —°0345 1839 ...... —"0516 ...... —‘0498 ..... . —°0305 Variation reduced to 0°01 Centigrade. In trap. In sand. In sandstone. For 1837 ...... 58°1 feet . 72°2 feet . 97°3 feet. 1838 ..ccee 49°3 wees GIS ses. QI BSG atten DOS: vovses OO7 OD acess OO Velocity of propagation for one foot of depth. In trap. In sand. In sandstone. In 1837 ...... 7-5days. 71 days. 4°9 days. 1838 ..ocee GB cscves GB ceovee 3°6 1839 seevce 78 secece 2 ee ee6 46 Report on the Action of Osler’s Anemometer at Edinburgh. I BEG to report, that Mr. Osler’s Anemometer has been erected at Edinburgh, according to the desire expressed by the British Association at Birmingham, and that the members of the Astro- * The formula in the notation of M. Quetelet is Log. A, = A + Bp Where Ap» represents the Annual Range in centigrade degrees at a depth p in French feet. A is the logarithm of the Superficial Range, and B is a constant # the soil. The values of A and B are deduced from the Annual Ranges alone. determining the propagation downwards, and proportional to DR os 436 REPORT—1840. nomical Institution have afforded every facility for its erection, and have removed their camera-obscura for that purpose. Mr. Osler has furnished the instrument below prime-cost, but I regret to say, that the unavoidable expenditure for put- ting the instrument in working order, carriage, and placing it in its present position, amounts to 31/.; so that the sum of 60/., granted by the Association, has been exceeded by 112. I have, however, the satisfaction of stating, that the Anemometer is now in complete work, under the superintend- ence of Prof. Henderson and Mr. Wallace, of the Edinburgh Observatory. J. D. Forses. Glasgow, September 23, 1840. On the part of a Committee appointed for the purpose of caus- ing a plate to he engraved for printing paper ruled in squares, Prof. Forbes reported,— That the plate was engraved, and that the paper, 22 inches by 26, and ruled in squares of one tenth of an inch, each tenth line being stronger than the others, was ready for the service of the members of the Association, at cost price, on application to Messrs. Johnston, Engravers, Edinburgh. Report on the Application of a Portion of the Sum of Fifty Pounds, voted by the British Association at its Meeting at Birmingham, in 1839, for Discussion of Tide Observations. By the Rev. W. WHEWELL. (With a Plate.) A portion of this sum has been expended upon calculations, having for their object to determine the effect of the moon’s de- clination upon the tides. The determination of this correction is attended with peculiar difficulties, and has hitherto been incom- pletely effected. Thesedifficulties arise from this: that the moon’s mean declination is different in different years, through a cycle of eighteen years, the period of revolution of her nodes. The inclination of her orbit to the equator varies from about 18° 20’, its amount in 1829 and 1830, to 28° 40’, its amount in 1837 and 1838. Hence, if we attempt to determine the declination correction (of height, for instance) by taking the difference of the height from the mean height (allowance being made for other corrections), we refer to a variable standard. Accordingly, if we find from the observations the mean semimenstrual ine- quality for the successive years, it will be different in conse- quence of the different mean declinations in successive years ; and it is only by taking a series of nine or more years that we PROVISIONAL REPORTS, AND NOTICES. 437 can obtain the absolute mean semimenstrual inequality, and consequently the absolute correction for declination applicable to all years alike. This being known to be the case, I was dis- posed to take advantage of an opportunity which occurred of discussing a series of several years’ tide observations, with a view to the verifying in fact these theoretical features of the correction tables, and determining the correction for declina- tion. Mr. Dall, the Harbour Master at Leith, had made a se- ries of tide observations, extending from 1827 to 1839, which I had every reason to believe to be accurate; and Mr. Ross, of the Hydrographer’s office, had, for his own satisfaction, begun to arrange these observations, with a view to discussions rela- tive to lunar declination and parallax. The latter gentleman undertook, at my request, to conduct his discussion in such a manner that it might bring into view such results as I have above described. The arrangement and discussion of thirteen years’ observations of tides (involving the management of above 18,000 numbers given by observation, and double the number extracted from tables,) was, of course, a business of very great labour and time; but as this task was not originally suggested by the Bri- tish Association, nor directed exclusively to objects pointed out by it, I thought it my duty to confine my expenditure within a sum very disproportionate to the magnitude of the labour. Mr. Ross has been paid 20/. for his discussion of the above-men- tioned heights, with a view to the declination correction. The result of this discussion is very nearly what I had anticipated. The semimenstrual lines taken for different years, differ by the effect of the different mean declination. Thus the correct mean of the height of high water for each hour of transit, is about six inches less in 1837 than in 1829, and this difference is ba- lanced by a difference in the declination correction which is to be applied to this mean. The declination correction is greater in 1837 than in 1829 for equal declinations. The difference, however, is net constant, but increases with the declination, which agrees with what the theory indicates. The curves which express this correction, deviate considerably from each other at the higher declinations. This result suggests an improved me- thod of applying the declination correction to tide observations, which, however, requires to be further considered and examined before it can be confidently recommended: I mean, a method of using a different semimenstrual inequality and different de- clination correction for every different period of the moon’s nodes. On this subject it may hereafter be possible to speak more decidedly. W. WaHEWELL, 438 REPORT— 1840, Another portion of the sum placed at my disposal has been expended upon calculations and operations performed by Mr. Bunt. These calculations were in the first place directed to the determination of the form of the curve of rise and fall of the tides at Bristol. This determination was the more desirable, inasmuch:as calculations were in progress at the Admiralty (under my directions) for the purpose of determining the form of the curve of the rise and fall at Liverpool and at Plymouth. The results of these calculations have been laid before the Royal Society, and are now printed by them in the Philosophical Transactions, as the twelfth series of my Researches on the Tides. The accompanying communication from Mr. Bunt con- tains the result of his investigations on this subject. The thing principally discussed was the displacement of the summit of the curve of rise and fall; that is, the difference of the time of high water actually observed, and the time obtained by bisecting the interval between equal altitudes, before and after high water. The main object was, to refer this displacement to its proper argument. It was natural to suppose that it depended mainly upon the height of the tidal wave, and, consequently, upon the age of the moon; and hence would principally consist of a se- mimenstrual inequality. But by the discussions, it appears that there is, besides this fact, one which depends upon the solar parallax, and also others. This would lead, as Mr. Bunt remarks, to a suspicionthat meteorological causes are concerned in producing the result ; the subject, however, is as yet not free from difficulty. IT have also employed Mr. Bunt in other dis- cussions, with a view to further improvements in our knowledge of the laws of the tides, especially with reference to two points : —the determination of the best anterior epoch, or period, at which that anterior transit of the moon is to be assumed which governs the tide :—and the solar corrections for parallax and declination. The excellence of the Bristol observations made with Mr. Bunt’s machine, and of his modes of discussing the observations, induce me to believe that some progress may still be made in this inquiry ; but the investigation is not yet com- pleted. I have also taken the liberty of directing Mr. Bunt to perform an operation not precisely included in the terms of the grant made to me for the present year, but closely connected with it, and forming an almost necessary sequel to a large ope- ration performed at the expense of the Association in preceding years ; I mean, a repetition of the levelling of a portion of the level line in the neighbourhood of the recent landslip in Devon- shire. The southern extremity of the line leveled from the Bristol Channel to the English Channel is at Axmouth. When PROVISIONAL REPORTS, AND NOTICES. 439 the great landslip took place in that neighbourhood, it might naturally be suspected that a part of the level line might be dis- turbed. A moment’s reflection made this appear improbable, since the movement seemed to be confined to the chalk and the clay below it ; whereas the terminus of the level line was bedded in the red marl. Still, if the movement of the ground were the result of an earthquake, even the inferior strata might have been slightly stirred; and this appeared to be exactly one of the cases, the decision of which was contemplated in the project of the level line. I therefore requested Mr. Bunt to repeat the levelling of the line from the mark in the church tower, in the village of Axmouth, down to the shore, where is the granite block which forms the terminus of the line, a distance of six sevenths of a mile. In July of the present year this operation was performed (with the same instruments as before), and it ap- peared that the mark in the church tower was above the mark RepeeaerlGcle | hata yeti al Ll wie elo Tor BBR S eats which in July 1838 had been found to be. . . 5°8805 feet. The difference, one twenty-seventh of an inch, may be consi- dered as a proof that there has been no sensible change. Mr. Bunt also leveled from the granite block, about 230 yards, to another bench mark eastwards, or towards the landslip, but found no difference of any importance. The expense of this operation, 10/., I have taken the liberty of including in the ac- count for tide discussions. W. WHEWELL. “Dear Sir, **I send you the results I have obtained from an elaborate investigation of ten years’ observations of the ‘ Displacement of Summit’ of the tide-gauge curves. The observed quan- tities themselves being so small, seldom exceeding 5 or 6 mi- nutes, I at first thought that they scarcely admitted of being treated in a similar manner to the ordinary observations of time and height, in which the corrections are gradually ob- tained, by approximation. On further consideration, however, I determined to try ; not knowing in what way to improve upon my former results. I therefore drew on the sheets a new line of observation (cutting off only the diurnalinequality), to avertical scale of 3 times the size of my old one, which had always been a scale of 40 min. per inch. ‘This afforded me sufficient size to go to work, on my former principles of approximation, by drawing in, on the line of observation, successive pencil curves of semimenstrual inequality, lunar parallax, and declination, and of solar correction, from the corrections first obtained, 440 REPORT—1840. and arranging the residues (which would have been otherwise too small), so as to improve the first corrections. The acci- dental irregularities of the observations, being of course also magnified, gave me a very irregular line to work from ; not- withstanding which, I believe the attempt at improvement by approximation has been as successful in this instance as it has proved on former occasions. “You will perceive that the curves of Lunar Declination ° | a are almost exactly similar to the curves of Lunar Parallax rel { * \ 3 the effects of the Jarger declinations agreeing with those of the smailer parallaxes, and the curves crossing each other at almost exactly the same nodal points, viz. 33" and 8235 of transit. «There is not the same agreement between the solar curves of declination and parallax ; yet it is observable that neither of these pairs of curves produces a loop, as the lunar curves do ; the curve of 22 (large) declinations, like that of 8!'-45 (small) parallax, always keeping above the other, except at the hour of 84, where the curves touch, but do not cross. “The points at the middle of each hour of transit were laid down, without any alteration, from the differences of the two parcels of observations, after taking theaverages. Thestraightness of the axis is arbitrary. “The magnitude of the corrections is quite as great as could be expected from observations which do not themselves ave- rage more than about five minutes. ‘The great difference of effects corresponding to the maximum and minimum of solar parallax, would lead to a suspicion that meteorological causes were concerned in producing them; the maximum and minimum of solar parallax nearly coinciding with midwinter and midsummer. Such causes cannot, however, ex- plain the forms assumed by the curves corresponding with the arrangements of the observations for the maxima and minima of lunar parallax and declination; especially the former, which is more clearly independent of weather or season. There is also a diurnal inequality plainly to be seen in many parts of the curve of observation, which cannot arise from merely local or meteorological causes. **T shall be very glad to know what you think of these curves, and how they bear on the theory. I am quite satisfied that they very nearly represent any agreement that exists between the observations and the arguments to which they have been referred. I shall also be glad to be informed of any results which you may PROVISIONAL REPORTS, AND NOTICES. 44] have arrived at in the course of your own investigations of the same subject. *“T have also made some progress in the discussion of the heights with a view to the determination of the best anterior epoch, and to the solar correction. I have laid down the two years’ observations made by means of my machine, but have not obtained any of the correction curves as yet. “« The two tide-gauges for the East Indies are very nearly com- pleted. I have had a visit from another engineer officer in the Company’s service, a Lieut. Ludlow, who stayed here three or four days to study my machine. Lieut. Elliott has written to say he intends coming again to Bristol, as soon as the new instru- ments are finished, in order to make himself more perfectly ac- quainted with all their details. Both these gentlemen expressed themselves as being highly pleased with my tide-gauge. It has been working now for more than seven months without the slight- est derangement, or the loss of a single observation. **T do not think that I mentioned to you the extraordinary tide which occurred here in October, 1838, when the water in our river rose to nearly 8 feet above its proper height, in consequence of a hurricane, as shown by the adjacent heights of the series of tides, from which it differs by that quantity, thus: “TI am, dear Sir, yours very respectfully, “THos. G. Bunt.” “ Bristol, 27th Jan., 1840.” On Waves.—By a Committee, consisting of Sir J. Robison and J. 8S. Russell, Esq. All the objects which had been confided to this Committee having been fully accomplished, the report now presented was to be considered as final. The objects originally committed to them for investigation were—the Phenomena of Waves propa- gated in Liquids; the connexion of these Phenomena with the resistance of Liquids to the motion of Floating Bodies ; and the nature of the connexion which subsists between the Tidal Wave and Mr. Russell’s great solitary Wave of Translation. Since the publication of their furmer report, the phenomena of Waves had occupied the attention of eminent mathematicians, who had endeavoured to deduce from first principles the curi- 442 REPORT—1840. ous phenomena which the Committee had observed, so as to reconcile theory with experiment. ‘The Astronomer Royal, Mr. Green, and Professor Kelland, had all been engaged on the subject; and the two latter had published memoirs in the Transactions of Cambridge and Edinburgh, in which they had succeeded in obtaining from analysis many of the very singular results published in the former report of the Committee. There still, however, remained difficulties which they had not been able to conquer; but as Mr. Kelland was about to lay before the Section his own investigations, it had become unnecessary to include them in this report. The subject which had chiefly engaged the Committee during the last year, was the conclusion and discussion of ob- servations on the Tidal Wave of the Frith of Forth. This tidal wave presented some very singular features; and, for the purpose of determining its phenomena with accuracy, a standard line had been levelled with great accuracy, under the direction of Mr. James Aden, C.E., and observations made at a great number of stations, the rise and fall of the tide being observed every five minutes. In this channel were ob- served the singular phenomena of four tides, or two double tides, every day; and, on some occasions, six tides, or two triple tides were observed. ‘These had all been accurately laid down from the levels; and it appeared that the top of high water rose at Stirling to the height of sometimes as much as ten feet above the level of the tides at Leith. The tides were of this form: J A, a common Tide-Wave. D B, the Tide-Wave of Leith. C, the Tide-Wave of Alloa. D, Tide-Wave near Stirling. 0 Mr. Russell had formerly intimated his expectation that this second tide was the great southern tide-wave of the English >a a PROVISIONAL REPORTS, AND NOTICES. 443 Channel entering the Forth before the northern tide-wave, coming round by the Shetland Islands, and afterwards ex- aggerated,—first, by the dislocation of the wave, and next, by the narrowing of the channel; and the velocities of these re- spective waves appeared to be just what was necessary to this effect. He had also found a similar appearance in the tide- wave of the river Tay, which he attributed to the same cause. These phenomena appeared to throw considerable light on the mechanical constitution of tidal waves. It appeared that, like the great wave of Translation, tidal waves could not only meet and cover each other without losing their individuality, but that they could also pass over each other when going in the same direction. That part of the duties of the Committee which related to the connexion of the phenomena of waves with the resistance of fluids to solids, had been devolved upon them under a sepa- rate name, as the Committee on Forms of Vessels, and would be reported by them under a separate head. The wave-form of vessels, however, had been now proved to possess so many ad- vantages, that its use seemed likely to become general, and thus a great change would be effected in the naval architec- ture. GEOLOGY AND GEOGRAPHY. Proressor JoHNstTon presented to this Section a portion of his Report on Inerganic Chemistry, relating to the nature and origin of Coal. On the subject of the application to the Trustees of the British Museum, for enlarged exhibitions in illustration of Recent and Fossil Conchology*, the Marquis of Northampton re- ported,— That the Trustees of the British Museum had resolved, that a commencement of such an arrangement should be made, and that the duplicates of their fossil shells and other Invertebrata, should be handed over to Mr. Gray, for the purpose of being arranged with their recent analogous species and genera, where there are any such. On British Fossil Reptiles. By Professor Owen, F.R.S. Pror. Owen reported,—That in order to complete his mate- rials for the continuation of his Report on British Fossil Rep- * Report for 1839, p. xxiii. 444 REPORT— 1840. tites, he had inspected many considerable collections in differ- ent parts of England, and collected abundance of new informa- tion, which he fully expected to be able to digest into regular order, so as to present a continuation of his report on the sub- ject at the next meeting. Mr. Stevenson’s teport on the relative Level of Land and Sea was read. NaruraAv Hisrory, Ar the last Meeting of the British Association, a Committee was appointed for procuring drawings illustrative of the Spe- cies and their details of the Radiate Animals of the British Islands, to accompany a Report of the state of our knowledge of such Animals, and the sum of 50/. was placed at their dis- vosal. Respecting the state of our knowledge of two divisions of the Radiate Animals, the Committee feel it unnecessary to furnish any report, these departments being undertaken by individual members of the Committee, whose researches are either pub- lished, or are now in course of publication*. With regard to the remaining portion, the Acalepha, they are persuaded it cannot be effectually investigated and illustrated, except when the artist and the naturalist are combined in the person of one individual. ‘The Committee, therefore, after an expendi- ture of only two pounds, now bring forward the drawings they have ‘had prepared, and, for the reasons assigned, beg leave to discontinue the further prosecution of the subject. Tur Committee appointed at the last Meeting of the British Association, for the investigation of the Marine Zoology of Great Britain, by means of the dredge, lave to report the ex- penditure of 152. out of the 50/. granted for that purpose. The state of the weather, which prevented dredging in the open sea during a great part of the summer, and the dittculty of obtain- ing observations sufficiently precise in information respecting species, have been the causes which have operated against them, and caused the expenditure of so small a portion of the grant. A series of queries, and printed formule to be filled up with the results of the dredging excursions, were prepared and * Johnston’s Zoophytes, and Forbes’s Echinodermata. PROVISIONAL REPORTS, AND NOTICES. 445 distributed. A Sub-Committee, consisting of Mr. Thompson, Mr. Ball and Mr. Forbes, examined a considerable portion of the west coast of Ireland; Mr. Patterson undertook the exami- nation of the north-east coast of the same country; and Mr. Forbes dredged the coasts of the Isle of Man. The results of these researches were very satisfactory, and the products in every case carefully noted down in the printed formule. The Committee recommend further researches, and propose that the dredging-papers be laid by for the present, until a sufficient amount of data be obtained to warrant the publication of a sum- mary of their contents. On the recommendation (a grant adopted in 1839) for en- graving Skeleton Maps for recording the distribution of Plants and Animals, the Committee reported at length the measures they have taken for executing these maps, on certain prin- ciples, believed to be of undoubted importance. They have caused three maps to be prepared and lithographed, one of the British Isles, and one of each hemisphere. The work was entrusted to Mr. Nichol, the lithographer, under the superin- tendence of Mr. Brand. This member of the Committee having been for some time engaged in preparing tables or catalogues for the Botanical Society of Edinburgh, which should include a variety of topographical details, it was thought proper to carry on both these plans together. On the maps, the details chiefly sought to be given with fulness are the river and moun- tain systems, the measures of the chief elevations, and important lakes. The maps are not yet considered by the Committee, though repeatedly revised, to be complete; but they recom- mend that, after having been finally settled, copies should be printed off, and sold at the lowest remunerating price to all who may wish copies for natural history purposes. As an illustra- tion of the way in which these maps may be usefully employed, the Botanical Society of Edinburgh caused to be represented in coloured outlines on their maps, from another stone, the ‘sec- tions’ of the earth’s surface, which are an important part of the system of arranging botanical information before alluded to. The numbers being attached to the several sections on the map so coloured, immediate reference can be made to the cata- logue sheets which have been prepared for botanical registra- tion by the Botanical Society. (Copies of the maps and cata- logue sheets were presented to the meeting.) 446 REPORT— 1840. STATISTICS. Pror. Jounston reported the progress made by the Com- mittee appointed at the Newcastle Meeting to inquire into the Statistics of the Mining Districts. MECHANICAL SCIENCE. On the Forms of Vessels.—By a Committee, consisting of Sir J. Robison, J. S. Russell, Esq., and James Smith, Esq. On THE TRANSLATION OF FOREIGN SCIENTIFIC MEMorRs. At the Meeting of the British Association at Newcastle in 1838, a Committee was appointed for the purpose of procuring and publishing translations of foreign scientific memoirs, and a sum of 100/. was placed at their disposal: and at the Meeting at Birmingham in 1839, a further sum of 100/. was allotted for the same object. The memoirs translated in the first year, under the superintendence of the Committee, and at the expense of the Association, were— 1. Remarks on the arrangement of magnetical observatories, and a descrip- tion of the instruments to be placed in them (with one plate), by Weber. 2. Method to be pursued during the magnetical term-observations by Gauss. 3. Extract from the daily observations of magnetical declination during three years, at Gottingen, by Gauss. 4. Description of a small portable apparatus for measuring the absolute in- tensity of terrestrial magnetism (with one plate), by Weber. 5. On the graphical representations of the magnetic term-observations (with two plates), by Gauss. 6. On a new instrument for the direct observation of the changes of the intensity in the horizontal portion of the terrestrial magnetic force, by Gauss. 7. On the arrangement and use of the bifilar magnetometer, by Weber. For the translation and publication of these in Taylor’s Sci- entific Memoirs, the first year’s grant of 100/. was paid to Mr. Taylor. In the present year, Ohm’s memoir, entitled “‘ The Galvanic Circuit investigated mathematically,” has been translated at the expense of the Association, and given to Mr. Taylor, for the seventh and eighth numbers of the “‘ Scientific Memoirs.” The Association have also paid for seven plates contained in the seventh number, representing the lines of magnetic declination, inclination and intensity computed by M. Gauss’s theory. The sums paid for these plates and for the translation of Ohm’s PROVISIONAL REPORTS, AND NOTICES. 447 memoir, and the plate which accompanies it, amount to 63/., which is the whole charge for the present year. ‘The Committee report that translations have been gratuitously presented to them by Major Sabine, of the five undermentioned memoirs on mag- netical instruments, and on subjects of prominent interest in mathematical and physical science. 1. Gauss.—General theory of terrestrial magnetism. 2. Encke.—On the method of least squares. 3. Bessel.—On the determination of the axes of the elliptic spheriod of revo- lution, which most nearly corresponds to the existing measurements of arcs of the meridian. 4. Weber.—Description and use of a transportable magnetometer. 5. Bessel.—On the barometrical measurement of heights. The Committee placed these translations in the hands of Mr. Taylor, by whom they have been printed in the sixth, se- venth and eighth numbers of the “Scientific Memoirs.” The Committee further acknowledge the receipt of a translation of Rudberg’s experiments ‘‘ On the expansion of Dry Air,” gra- tuitously presented by Professor Miller, of Cambridge. This translation has also been placed in Mr. Taylor’s hands, and will make a part of the eighth number of the “ Scientific Me- moirs.” VARIETIES OF HUMAN RACE. Queries respecting the Human Race, to be addressed to Tra- vellers and others. Drawn up by a Committee of the British Association for the Advancement of Science, appointed in 1839. Ar the meeting of the British Association held at Birmingham, Dr. Prichard read a paper ‘‘On the Extinction of some varieties of the Human Race.” He pointed out instances in which this extinction had already taken place to a great extent, and showed that many races now existing are likely, at no distant pei to be annihilated. He pointed out the irretrievable oss which science must sustain, if so large a portion of the hu- man race, counting by tribes instead of individuals, is suffered to perish, before many interesting questions of a psychological, physiological and philological character, as well as many histo- rical facts in relation to them, have been investigated. Whence he argued that science, as well as humanity, is interested in the efforts which are made to rescue them, and to preserve from oblivion many important details connected with them. At the suggestion of the Natural Historical Section, to which Dr. Prichard’s paper was read, the Association voted the sum of 448 REPORT—1840. £5 to be expended in printing a set of queries to be addressed to those who may travel or reside in parts of the globe inhabited by the threatened races. A Committee was likewise appointed by the same Section to prepare a list of such questions. The following pages, to which the attention of travellers and others js earnestly invited, have, in consequence, been produced. It is right to observe, that whilst these questions have been in pre- paration, the Ethnographical Society of Paris has printed a set of questions on the same subject for the use of travellers. It has been gratifying to perceive the general similarity between the questions proposed by the French savans who compose that So- ciety, and those which had been already prepared by the Com- mittee; but the Committee is bound to acknowledge the assist- ance which, in the completion of its task, it has derived from the comprehensive character and general arrangement of the Ethnographical Society’s list. The following queries might have been considerably extended, and much might have been added to explain the reasons and motives on which some of them are founded. Such additions would, however, have in- conveniently extended these pages, and, in part, have defeated their object. The Committee has only further to express its desire that the Association may continue its support to the in- teresting subject of Ethnography, and that their fellow-mem- bers will aid in bringing these queries under the notice of those who may have it in their power to obtain replies. Britain, in her extensive colonial possessions and commerce, and in the number and intelligence of her naval officers, possesses unrivalled facilities for the elucidation of the whole subject ; and it would be a stain on her character, as well as a loss to humanity, were she to allow herself to be left behind by other nations in this inquiry. It will be desirable, before giving direct answers to the ques- tions proposed in the following list, that the traveller should offer, in his own terms, a description of the particular group of human beings, which he may have in view in drawing up his» list of answers, seeing that the replies, however accurate and replete with useful information, may fail in some particulars to give a complete idea of the people to whom they relate. Physical Characters. 1. State the general stature of the people, and confirm this by some actual measurements. Measurement may be applied to absolute height, and also to proportions, to be referred to in subsequent queries. The weight of individuals, when ascer- tainable, and extreme cases, as well as the average, will be in- PROVISIONAL REPORTS AND NOTICES. 449 teresting. What may be the relative differences in stature and dimensions, between males and females ? 2. Is there any prevailing disproportion between different parts of the body? as, for example, in the size of the head, the deficient or excessive development of upper or lower extremi- ties. 3. What is the prevailing complexion? This should be ac- curately defined, if possible, by illustrative and intelligent ex- ample, such as by comparison with those whose colour is well known. The colour of the hair should be stated, and its cha- racter, whether fine or coarse, straight, curled, or woolly. The colour and character of the eyes should likewise be described. Is there, independently of want of cleanliness, any perceptible peculiarity of odour? 4. The head is so important as distinctive of race, that particu- lar attention must be paid to it. Is it round or elongated in either direction, and what is the shape of the face, broad, oval, lozenge-shaped, or of any other marked form? It will contri- bute to facilitate the understanding of other descriptions, to have sketches of several typical specimens. A profile, and also a front view should be given. In the profile, particularly notice the height and angle of the forehead, the situation of the meatus auditorius, and the form of the posterior part of the head. It will also be desirable to depict the external ear, so as to convey the form and proportion of its several parts. The form of the head may be minutely and accurately described by employing the divisions and terms introduced by craniologists, and the corresponding development of moral and intellectual character should in conjunction be faithfully stated. So much of the neck should be given with the profile as to show the setting on of the head. The advance or recession of the chin, and the character of the lips and nose, may likewise be given in profile. The front view should exhibit the width of forehead, temples, and cheek-bones, the direction of the eyes, and the width between them : the dimensions of the mouth. When skulls can be col- _ lected or examined, it would be desirable to give a view in an- other direction, which may even be done, though with less ac- curacy, from the living subject. It should be taken by looking down upon the head from above, so as to give an idea of the contour of the forehead, and the width of the skull across from one parietal protuberance to the other. 5. State whether the bones of the skull are thick, thin, heavy, or light. Is it common to find the frontal bone divided by a mid- dle suture or not? Note the form of the outer orbitar process, which sometimes forms part of a broad scalene triangle, with 1840. 26 : 450 REPORT—1840. the vertex downwards. How are the frontal sinuses developed ? Observe whether the ossa triquetra are frequent, or otherwise ; whether there be frequent separation of the upper part of the os occipitis ; the relative situation of the foramenmagnum. In regard to the bones of the face, notice the position of the ossa nasi and unguis ; the former sometimes meet nearly or quite on the same plane, whilst, in others, they meet at an angle. The former character is strongly marked in many African skulls. State the form of the jaw-bone, shape of the chin, and observe the angle of the jaw, the position and character of the teeth, and their mode of wear; and if they have any practice of modifying their form or appearance, let this be stated. The malar bones have already been noticed, but they may require a more minute description. 6. When the opportunity can be found, observe the number of lumbar vertebre, since an additional one is said to be com- mon in some tribes. 7. Give the length of the sternum as compared with the whole trunk; and also some idea of the relative proportion between the chest and the abdomen. 8. What is the character of the pelvis in both sexes, and what is the form of the foot ? 9. The form of the scapula will also deserve attention, more especially as regards its breadth and strength ; and the strength or weakness of the clavicle should be noticed in connection with it. 10. The internal organs, and blood-vessels will with greater difficulty be subjected to examination ; but it may be well here to remark, that varieties in these may prevail locally in connec- tion with race. N.B.—Peculiarities may exist, which cannot be anticipated in queries, but which the observer will do well to notice amongst his answers to anatomical questions. 11. Where a district obviously possesses two or more varieties of the human race, note the typical characters of each in their most distinct form, and indicate to what known groups or fami- lies they may belong: give some idea of the proportion of each, and state the result of their intermixture on physical and moral character. When it can be ascertained, state how long inter- mixture has existed, and of which the physical char acterstend to predominate. It is to be observed, that this question does not so much refer to the numerical strength or political ascend- ency of any of the types, but to the greater or less physical resemblance which the offspring may bear to the parents, and what are the characters which they may appear to derive from PROVISIONAL REPORTS AND NOTICES. 451 each: whether there is a marked difference arising from the father or the mother belonging to one of the types in preference to an- other ; also whether the mixed form resulting from such inter- marriage is known to possess a permanent character, or after a certain number of generations to incline to one or other of its component types. 12. Any observation connected with these intermarriages, relating to health, longevity, physical and intellectual character, will be particularly interesting, as bringing light on a field hitherto but little systematically investigated. Even when the people appear to be nearly or quite free from intermixture, their habits, in respect of intermarriage within larger or smaller circles, and the corresponding physical characters of the peo- ple, will be very interesting. Language. 13. Do the natives speak a language already known to phi- lologists, and if so, state what it is; and notice whether it ex- hibit any dialectic peculiarities, as well as the modifications of pronunciation and accentuation which it may offer. State also the extent to which this dialect may be used, if limits can be ascertained, 14. If the language be little if at all known, endeavour to obtain a vocabulary as extensive as circumstances will allow, and at least consisting of the numerals, the most common and important substantives *, the pronouns in all persons and num- bers, adjectives expressive of the commonest qualities, and, if possible, a few verbs varied in time and person. The vocabu- lary should be tested by the interrogation of different natives, and more than one person should be engaged in taking it down from their mouths, to avoid, as far as may be, errors arising from peculiarities of utterance or defect of hearing. It is like- wise of importance that the system of orthography be duly in- dicated and strictly adhered to. 15. Endeavour to take down some piece of native composition, such as the ordinary phrases employed in conversation, and any other piece of prose which may be attainable ; and specimens of metrical composition if such exist. Though these would be of comparatively little use without translation, yet independently of this some importance is to be attached to the metrical compo- sitions if they have a national character and are widely diffused ; and, in this case, it might be possible to express some of their airs in musical characters. A specimen of known composition translated into their language, may also be given, such as the * The names of mountains, lakes, rivers, islands, &c, 262 452 REPORT—1840. first chapter of Genesis, the fifteenth chapter of Luke’s Gospel, and the Lord’s Prayer. 16. Endeavour to ascertain whether the language is exten- sively spoken or understood, and whether there are different languages spoken by men having similar physical characters obviously connecting them as a race, or if differing somewhat in this respect, inhabiting a particular geographical tract. When such groups are said to possess different languages, endeavour, as far as possible, to ascertain their number, the sources whence each is derived, and the languages to which it is allied; and also the circumstances, geographical or political, which may account for these distinctions. (For further information connected with the investigation of languages, reference is made to a short essay on this subject read to the Philological Society of London. ] Individual and Family Life. 17. Are there any ceremonies connected with the birth of a child? Is there any difference whether the child be male or female ? 18. Does infanticide occur to any considerable extent, and if it does, to what causes is it to be referred, want of affection, deficient subsistence, or superstition ? 19. Are children exposed, and from what causes, whether superstition, want of subsistence or other difficulties, or from deformity, general infirmity, or other causes of aversion ? 20. What is the practice as to dressing and cradling children, and are there any circumstances connected with it calculated to modify their form ; for example, to compress the forehead, as amongst the western Americans; to flatten the occiput, as amongst most Americans, by the flat straight board to which the child is attached; to occasion the lateral distortion of the head, by allowing it to remain too long in one position on the hand of the nurse, as amongst the inhabitants of the South Seas? 21. Are there any methods adopted, by which other parts of the body may be affected, such as the turning in of the toes, as amongst the North Americans; the modification of the whole foot, as amongst the Chinese ? 22. How are the children educated, what are they taught, and are any methods adopted to modify their character, such as to implant courage, impatience of control, endurance of pain and privation, or, on the contrary, submission, and to what authorities, cowardice, artifice ? 23. Is there anything remarkable amongst the sports and amusements of children, or in their infantile songs or tales ? PROVISIONAL REPORTS AND NOTICES. 453 24. At what age does puberty take place? 25. What is the ordinary size of families, and are there any large ones ? 26. Are births of more than one child common? What is the proportion of the sexes at birth and among adults ? 27. Are the children easily reared ? 28. Is there any remarkable deficiency or perfection in any of the senses? It is stated, that in some races sight is re- markably keen, both for near and distant objects. 29. To what age do the females continue to bear children ? and for what period are they in the habit of suckling them ? 30. What is the menstrual period, and what the time of utero-gestation ? 31. Are there any ceremonies connected with any particular period of life ? 32. Is chastity cultivated, or is it remarkably defective, and are there any classes amongst the people of either sex by whom it is remarkably cultivated, or the reverse, either generally or on particular occasions ? 33. Are there any superstitions connected with this subject ? 34. What are the ceremonies and practices connected with marriage ? 35. Is polygamy permitted and practised, and to what extent ? 36. Is divorce tolerated, or frequent? 37. How are widows treated ? 38. What is the prevailing food of the people? Is it chiefly animal or vegetable, and whence is it derived in the two king- doms? Do they trust to what the bounty of nature provides, or have they means of modifying or controlling production, either in the cultivation of vegetables, or the rearing of animals ? Describe their modes of cooking, and state the kinds of condi- ment which may be employed. Do they reject any kinds of aliment from scruple, or an idea of uncleanness? Have they in use any kind of fermented or other form of exhilarating liquor, and, if so, how is it obtained? What number of meals do they make? and what is their capacity for temporary or sus- tained exertion ? 39. Describe the kind of dress worn by the people, and the materials employed in its formation. What are the differences in the usages of the sexes in this respect? Are there special dresses used for great occasions? and, if so, describe these, and their modes of ornament. Does any practice of tattooing, piercing, or otherwise modifying the person for the sake of ornament, prevail amongst the people? N.B. Such modifica- 454 REPORT—1840. tions not to be blended with other modifications used as signs of mourning, &c. 40. Have the people any prevailing characteristic or remark- able modes of amusement, such as dances and games exhibiting agility, strength or skill? 41. Are games of chance known to the people, and is there a strong passion for them ? 42. Do the people appear to be long- or short-lived? If any cases of extreme old age can be ascertained, please to state them. Such cases may sometimes be successfully ascertained by reference to known events, as the previous visits of Euro- peans to the country. Is there a marked difference between the sexes in respect of longevity ? 43. What is the general treatment of the sick? Are they cared for, or neglected? Are any diseases dreaded as conta- gious, and how are such treated? Is there any medical treat- ment adopted? Are there any superstitious or magical prac- tices connected with the treatment of the sick? What are the most prevailing forms of disease, whence derived, and to what extent? Is there any endemic affection, such as goitre, pelagra, plica, or the like? With what circumstances, situations, and habits do they appear to be connected, and to what are they referred by the people themselves ? 44, Where there are inferior animals associated with man, do they exhibit any corresponding liability to, or exemption from disease ? 45. Do entozoa prevail, and of what kind? 46. What is the method adopted for the disposal of the dead ? ? Is it generally adhered to, or subject to variation ? 47. Are any implements, articles of clothing, or food, do. sited with the dead ? 48. Is there any subsequent visitation of the dead, whether they are disposed of separately, or in conjunction with other bodies ? 49. What is the received idea respecting a future state? Does this bear the character of transmigration, invisible existence about their accustomed haunts, or removal to a distant abode? Buildings and Monuments. 50. What are the kinds of habitations in use among the people? Are they permanent or fixed? Do they consist of a single apartment, or of several? Are the dwellings collected into villages or towns, or are they scattered, and nearly or quite single? If the former, describe any arrangement of them in streets or otherwise which may be employed. PROVISIONAL REPORTS AND NOTICES. 455 51. Have any monuments been raised by the present inha- bitants or their predecessors, and more especially such as relate to religion or war? State their character, materials, and con- struction. If they are still in use amongst the people, state this object, even if they should be of the simplest construction, and be little more than mounds or tumuli. If these monu- ments are no longer in use, collect, as far as possible, the ideas and traditions of the natives regarding them, and, if possible, have them examined by excavation or otherwise, taking care to deface and disturb them as little as possible. 52. In these researches be on the look out for the remains of the skeletons of man or other animals, and, if discovered, let them be preserved for comparison with those still in existence. Works of .Art. 53. Let works of art, in metal, bone, or other materials, be likewise sought and preserved, and their similarity to, or differ- ence from implements at present in use amongst the people of the district, or elsewhere, be noted. 54. When a people display their ingenuity by the extent or variety of their works of art, it will not only be desirable to de- scribe what these are, but also the materials of which they are constructed, the modes in which these materials are obtained, the preparation which they undergo when any is required, and the instruments by which they are wrought. Such particulars will not only throw light on the character and origin of the people, but will, directly or indirectly, influence the commercial relations which may be profitably entered into when commerce alone is looked to. When colonization is contemplated, the facts contained in the replies to these queries will point out the mutual advantages which might be obtained by preserving, in- stead of annihilating, the aboriginal population. Domestic Animals. Are there any domestic animals in the possession of the people? Of what species are they? Whence do they appear to have been derived, and to what variety do they belong ? Have they degenerated or become otherwise modified? To what uses are they applied ? Government and Laws. 55. What is the form of government? Does it assume a monarchical or democratic character, or does it rest with the priests ? 56. Are the chiefs, whether of limited or absolute power, elective or hereditary ? 456 REPORT—1840. 57. Is there any division of clans or castes? a are the privileges enjoyed by or withheld from these ! 59. What care is taken to keep them distinct, and with what effect on the physical and moral character of each ? 60. What laws exist among the people? How are they preserved? Are they generally known, or confided to the me- mory of a chosen set of persons? What are their opinions and regulations in reference to property, and especially the occu- pation and possession of the soil? Does the practice of hiring labourers exist among them ? 61. Have they any knowledge or tradition of a legislator, to whom the formation of laws is ascribed ? 62. Do they rescind, add to, or modify their laws? and how? 63. Are they careful in the observance of them? 64. What are their modes of enforcing obedience, and of proving and punishing delinquency ? 65. How are judges constituted? Do their trials take place at stated periods, and in public? 66. How do they keep prisoners in custody, and treat them ? 67. What are the crimes taken cognizance of by the laws ? Is there gradation or commutation of punishment ? Geography and Statistics. 68. Briefly state the geographical limits and character of the region inhabited by the people to whom the replies relate. 69. State approximatively the number of inhabitants. As this is an important, but very difficult question, it may not be amiss to point out the modes in which the numbers may be ascer- tained. The people themselves may state their number with more or less accuracy, but it should be known whether they refer to all ranks and ages, or merely comprehend adult males, who may be mustered for war, or other general purpose re- quiring their combination. In this case state the apparent proportion between adult males and other members of families. The number of habitations in a particular settlement may be counted, and some idea of the average numbers of a family be given. Where the people inhabit the water-side, the num- ber and dimensions of their craft may be taken, and some idea of the proportion between the number of these and of the indi- viduals belonging to them, may be formed. In drawing con- clusions from observations of this kind, it will be necessary to have due regard to the different degrees of density or rarity in which, from various causes, population may be placed. PROVISIONAL REPORTS AND NOTICES. 457 70. Has the number of inhabitants sensibly varied, and within what period ? 71. If it have diminished, state the causes; such as sick- ness, starvation, war, and emigration. When these causes re- quire explanation, please to give it. If the inhabitants are on the increase, is this the result of the easy and favourable cir- cumstances of the people causing an excess of births over deaths; or is it to be assigned to any cause tending to bring accessions from other quarters? State whether such causes are of long standing, or recent. 72. Is the population generally living in a manner to which they have been long accustomed, or have new relations with other people, and consequently new customs and practices, been introduced ? 73. If the people, being uncivilized, have come under the in- fluence of the civilized, state to what people the latter belong, how they are regarded, and what is the kind of influence they are producing*. State the points of their good influence, if any, and those of an opposite character, as the introduction of dis- eases, vices, wars, want of independence, &c. 74. Is there any tendency to the union of races? how is it exhibited, and to what extent? Social Relations. 75. What kind of relationship, by written treaty or other- wise, subsists between the nation and other nations, civilized or not? Have they any intercourse by sea with other countries ? Do any of them understand any European Janguage? Or are there interpreters, by whom they can communicate with them ? 76. Are they peaceable, or addicted to war? Have they any forms of declaring war, or making peace? What is their mode of warfare, either by sea or land? their weapons and strategy? What do they do with the slain, and with prisoners? Have they any mode of commemorating victories by monuments, hieroglyphics, or preservation of individual trophies, and of what kind? Have they any national poems, sagas, or tradi- tions respecting their origin and history? Where Europeans have introduced fire-arms, ascertain the modes of warfare which have given place to them. State whatever particulars respecting their origin and history are derived, either from traditions among themselves or from other sources. * This question will comprise the existence of missions—the success or the want of it from causes connected with missionaries themselves or others. 458 REPORT—1840. Religion, Superstitions, &c. 77. Are tne people addicted to religious observances, or generally regardless of them ? 78. Do they adopt the idea of one great and presiding Spirit, or are they polytheists ? 79. If polytheism exist, what are the names, attributes, and fables connected with their deities, and what are the modes in which devotion is paid to each? Are any parts of the body held sacred, or the reverse? Do they offer sacrifices, and are they of an expiatory character, or mere gifts ? 80. Have they any sacred days or periods? fixed or move- able feasts, or religious ceremonies of any kind, or any form of thanksgiving or other observance connected with seasons ? 81. Have they any order of priests; and if so, are they here- ditary, elective, or determined by any particular circumstance ? 82. Is the religion of the people similar to that of any other people, neighbouring or remote? If different, are they widely so, or dependent on particular modifications, and of what kind? 83. In what light do they regard the religion and deities of neighbouring tribes ? 84. Is there any idea of an inferior order of spirits and ima- ginary beings,—such as ghosts, fairies, brownies, and goblins ; and how are they described ? 85. Have they any notions of magic, witchcraft, or second sight ? "36. What ideas are entertained respecting the heavenly bodies? Have they any distinction of stars, or constellations? and if so, what names do they give them, and what do these names signify ? 87. Are they in any manner observed with reference to the division of the year, and how ? 88. If time is not divided by observations of those bodies, what other mode is adopted? and do observances connected with them rest with the priests or chiefs ? 89. When the traveller, by personal acquaintance with the language, or by means of competent assistance from interpret- ers, can freely converse with the people, it will be desirable that he should form some idea of their amount of intelligence, their tone of mind with regard to social relations, as respects freedom, independence, or subserviency, and their recognition of moral obligations, and any other psychological character which observation may detect ; and more especially such as may contribute to an estimation of the probable results of efforts to develope and improve the character. NOTICES AND ABSTRACTS OF COMMUNICATIONS TO THE BRITISH ASSOCIATION ADVANCEMENT OF SCIENCE, AT THE GLASGOW MEETING, AUGUST 1840. ADVERTISEMENT. Tue Eprrors of the following Notices consider themselves respon- sible 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. ’ Dr. Forses on the mean Apsidal Angle of the Moon’s Orbit ............ Professor NicHox’s Account of the Observatory erecting near Glasgow Professor Arry on a New Apparent Polarity of Light ..................00. Sir Davip BrewsTER on Professor Powell’s Measures of the Indices of Refraction for the lines G and H in the Spectrum ..............00008 ——_—— on the Decomposition of Glass .............esee0ees on the Rings of Polarized Light pee in specimens of Decomposed Glass .........:sesessscnssteseeetersueceesseusceas on the Cause of the Increase of Colour ‘by the Mawersion) ofthe sead fot kas asics Soeaw cn oomands Seandeenan Datileiniinneeerens on the Phenomena and Cause of Muscz Volitantes on the Line of Visible Direction along the Axis of on the Camera Obscura, and other Apparatus, used in making Daguerreotype Drawings ...........sccecscsssscscseeseees ——— — Ona Method of Illuminating Microscopic Objects On an Improvement in the Polarizing Microscope Col. Rerp’s Letter to Sir David Brewster ..........cececsssssceeesersesescees Mr. Bowman on a remarkable Rainbow .........csessssecsevsescsccesedaces Rey. J. FisHer on remarkable Rainbows .........ssecscecscsceceeecsesescees Mr. A. Bexu on a new case of Interference ........sssccscsecsercevecscesecs Dr. JosepH RAD on the Iriscope .............sssececesscscececessvesessseees Professor Powe. on an Experiment of Interference ...............0ee008 on a point in the Wave-Theory as applied to Heat. Professor KELLAND on the Conduction of Heat ............csceeesesseeees Mr. Eaton Hopexrnson on the Temperature of the Earth in the deep Mines in the neighbourhood of Manchester ............sscecsececececeeee Professor Jacoz1 on the Principles of Electro-Magnetical Machines ... Mr. C. J. Kennepy on the Theory of Electricity ...............scceceeesees Dr. Lamont’s Account of the Magnetic Observatory of Munich ...... on a general statement of the System of Meteorological Observations carried on in Bavaria .........scscececscesscncscecstececececees Mr. Caupecort’s Notice accompanying a Series of Meteorological Ob- servations made at Trevandrum ........ssecsseececscesescececenseasececsaens Dr. ANDERSON on the Dew-Poinit ............ccscecssvescesccecccevccessessces Mr. Granam Hurcuinson on a Method of Prognosticating the proba- ble mean Temperature of the several Winter Months from that of cor- responding Months in the preceding Summer ............ Sevesslcesasaes Professor Forses on Excessive Falls of Rain..... en eeeans dakirataane. oueese Mr. Joun Puiiuips’s new Experimental Researches on Rain... eek eteeteer Mr. G. A. Rowe.t on the Formation of Rain .......... dadvadsaacaceaneees —— on the Cause of the Aurora, &.......csscesccessseceees iv CONTENTS. Mr. Witu1am Baxp’s Observations on the Tides in the Harbour of Glasgow, and the Velocity of the Tidal Wave in the Estuary of the River Clyde, between Glasgow and Port Glasgow .........ssseeeeeeeenees Rev. Professor KELLAND on the Theory of Waves..........sesesseserererers Mr. Suanp on the Agency of Sound ............scceeeesereeeeeeeeeeeeeeeeeens Mr. Granam ona Method of approximating to the Value of the Roots of Numerical Equations.......-..+-ssecsseesseeeeeeeeseeerseeeressessseasensenes Mr. Perstes on the Expressibility of the Roots of Algebraic Equations Mr. Fowxer’s new Calculating Machine .........s.secessncnenereneeeneweues Mr. Watsu on a Mode of solving Cubic Equations ............seseeeeeeee Mr. Wiii1aM Hoyue’s new Logarithmic Calculations and Views ...... Mr. P. MacFaruane on a new Construction of Barometer.........+.++++ Mr. Espy on the four daily Fluctuations of the Barometer .......++.++.+. Dr. ANDERSON on the Meteorology of Perth..........ssssecseeeeeeesenseens CHEMISTRY. Professor Toomas THomson on the most important Chemical Manufac- tures carried on in Glasgow and the neighbourhood .........+.sesseeee on the Minerals in the Neighbourhood of Glasgow ....csesseceeeccnreeccuseesaneeseusessoeesenesscesaessaeneceeeseesansceuens Dr. ScHAFHAEUTL on the Relation of Form to Chemical Composition —_—_—_ on anew Compound of Arsenious and Sulphuric Acids —____———— on a new Method of Photogenic Drawing ...........- Professor Lresic on Poisons, Contagions, and Miasms ........++++s0ee Professor Gregory on the Pre-existence of Urea in Uric Acid ......... —_______——- on a. new Process for preparing Murexide............ on the Preparation of Alloxan, Alloxantine, Thio- nurate of Ammonia, Uramile, and Murexide ............csseeceeseseeeeees Dr. R. W. Giover’s Process for preparing Hydrobromic and Hydrio- dic. AGIOS. «cisssaeiccwacteacn vacacnanecsaidimadesWaisee pen Genes Jalan de abesucnmeemes Professor ANDREW Bucuanan on a Method of separating, by Filtra- tion, the Coagulable Lymph from Liquid Human Blood ............... Professor REDTENBACHER and Dr. Varrentrapp on the Constitution and Products of the Distillation of Fat Bodies .........s.sseseeeeeeeeeees Dr. L. Puayrarr on a New Fat Acid .......ccccesescscsscseeeecsceccssesesees Professor BuNsEN on a New Mode of estimating Nitrogen in Organic Analysis ...ccecceeneseseeeeseeseesenanneeseesecessaeeeeeeesenenaraanneesseseeeaeas ~_————— on the Compound or Radical called Kakody] ......... Dr. Erruine on the Identity of Spiroilous and Saliculous Acid ......... Dr. Mour on a New Method of preparing Morphia and its Salts ...... Professor FREDERICK PENNY on the Action of Nitric Acid on the Chlo- rates, lodates, and Bromates of Potassa and Soda...........+ssss+sseee0s —_—_ on a New Salt obtained from Iodine and Caus- PIG SOMA. cccckacunaanaaqsascinicnminnaaindinla drlannelus sance Rtei mele MSls kiaiciet ose Sees Mr. ArtHuR Connex’s Additional Observations on the Voltaic De- composition of Alcohol .......sssessssseeeeeseseeeeeseeseeesererseneeeeeeannnens Professor JOHNSTON ON RESINS .......cscecsececseeececnecedecneasenerseeeeoens on the Resin of Sarcocolla ......ccsssceseseseeeeeeeee on some Varieties of Peat.......s.sesceeseereseeneeee Dr. CiarK on a Mode of Detecting Minute Portions of Arsenic......... Dr. R. D. THomson on the Tests for Sulphuric Acid when thrown on the (Pershore gscdanaaanhn seins ave lle sinila «nl scbabbideeuatedeantes hlaedstch URC ssi casted Mr. E. Sotzy on Bleaching Vegetable Wax .......csscccseeesscseeseenereees CONTENTS. Mr. SturGEon on a peculiar Class of Voltaic Phenomena ............... Mr. M‘Grecor’s Experiments on Carbonic Acid thrown off from the MMPIA EN sak ceits daca eee Rial wilds set bib aieeiule aclcWeu's boas Seleuebwancu Gels. atasnaelee = tse Mr. ALEXANDER Bryson’s Description of a New Instrument for Mea- suring the Refractive Power of Minute Bodies .........scsscseeeseeeeeees Mr. J. J. Grirrin on a New Method of Crystallographic Notation ... GEOLOGY. Mr. J. Crate on the Coal Formation of the West of Scotland .......... Mr. A. C. Ramsay’s Notes taken during the Surveys for the Construc- tion of the Geological Model Maps and Sections of the Island of Arran Mr. James Smiru’s Observations on the Superficial Beds in the Neigh- Dourheod: of Glasgow: :ssscssssssicsasscecdivcvecdssdeceesecsecdedeccscdeceecwae Mr. Witi1am Keir on the Geology of Castle Hill, Ardrossan .......... Rev. J. M. Fisuer on the Granite Formations of Newabbey, in Galloway Mr. D. Mrune on Earthquakes in Scotland ..........c.cececeeecscececeeeeee Mr. J. A. Knipz on the Sandstone of the Vale of Solway, and the For- mation of the Closeburn Basin, Nithsdale, Dumfries-shire ............ Mr.Rovertick Impey Murcuison on the Fishes of the Old Red Sandstone Mr. Jamus Yartss’s Account of the Footsteps of extinct Animals ob- served in a Quarry in Rathbone-street, Liverpool ...............ececeeees Mr. J. E. Bowman on the great development of the Upper Silurian Formation in the Vale of Llangollen, North Wales, and on a Plateau of Igneous Rocks on the East Flank of the Berwyn range............... Mr. Wiii1am Sanpers’s Account of a Raised Sea-beach at Woodspring- hill, near Bristol ......c.csccccccevecesccesnes POSS HORE ERO CE Sone CA EEEE SER ASaInAS Rev. Davip Wiuuiams on the Older Strata of Devonshire ............... Mr. Epwarp Forses on a Pleistocene Tract in the Isle of Man, and the relations of its Fauna to that of the neighbouring Sea ........... see Mr. Ropericx Impry Murcuison and M. E. pr VerneviL on the Stratified Deposits which occupy the Northern and Central Regions OM RUSSIOL ssisceesseesaseseccrasestetc’ BS Fhe a SS ed ee Mr. R. GrirritH on the Yellow Sandstone, and other points of the Geolemy: of Lreland jsssisens. teaeeetssudiesec ves covers. deveceverssesedvecteess Mr. Cuarues Lyext on the occurrence of two Species of Shells of the genus Conus, in the Lias, or Inferior Oolite near Caen, in N ormandy —__——_— on ancient Sea Cliffs and Needles in the Chalk of the Valley of the Seine in Normandy ..............ccccccsceececescesesenees Professor Acassiz on Glaciers and Boulders in Switzerland Capt. BappELzEy on the Geology and Mineralogy of Canada ............ Mr.James Rogs’s Remarks upon certain Geological Features of theRiver St. John in New Brunswick, with an account of the Falls upwards from the Sea, which occur near its Embouchure in the Bay of F undy Mr. James Smiru on the Geology of Madeira Mr. Grorce GarpNER on the Geology and Fossil Fishes of North PEAZIN sce ewancassnsne Sateaeans sekiguacitg sein seeee see Radi uuncuatehsauenssunseteces Mr. J. L. B. Isporson on the Daguerreotype, as applied to the Drawing PPMMMIEIR NG ces aca claitci Laciaeanon s dager ade esate Asuna MO ER AG hence kc ec ce nee Mr. G. H. FratHersTonHaveGH on the Geography of New Brunswick Sir J. E. ALExanpErR’s Outline of Three Expeditions which might be undertaken to explore portions of the interior of Africa Rev. Dr. E. Roprnson’s Additional Notes on the Wadi el ’Arabah in Syria M. A. Ravenstet1n’s Observations on Relief Maps .............ceceeceeees fe ecceresses eee eet e reese eeesceses eee eeereesceeee vi CONTENTS. Mr. Mature Hamitton’s Observations on Great Earthquakes on the West Coast of South America, particularly the great one of the 18th of September, 1833, which destroyed the City of Tacna, and other Places in Pert. .......scececeesceeeeereeeeees Rae cdsuesecadecdedundee dats eaeeaee tea Mr. Jutius Jerrreys on the Solvent Power exercised by Water at high temperatures on Siliceous Minerals ...........+4esseesee0e+ Pere nate Mr. Wiuttam Batp’s Account of the Construction of the Models of the Island of Achil, Clare Island, and the South-Western district of Mayo, in Ireland ..........sscesseseseneeeeesessnceecnecceeneseaeerssanes eeeeee ZOOLOGY AND BOTANY. Mr. Hueu E. Strickianp on the true Method of discovering the Na- tural System in Zoology and Botany .......sss+sseeseseseceneeeseneeseenees Professor Acassiz on the Development of the Fish in the Egg ......... Dr. Martin Barry on the First Changes consequent on Fecundation in the Mammiferous Ovum, with special reference to a Communica- tion ‘“‘ On the Development of the Fish in the Egg,”’ by Prof. Agassiz Mr. W. Danson on the Alpaca ......sccecscsesececeenccseeseececcccscccsessees Mr. G. T. Fox on the Subject of a Paper on the Structure of Whales, read at the Birmingham Meeting ........sscsecescseececeeecesescecessevees Dr. Macponatp on the Structure of Fishes, so far as the analogies can be traced between the Limbs of the Mammals and the Fins of Fishes Mr. James Wixson on the Salmon Fry.........-.++++ oceccenccscscscasoucnses Dr. Lizars on the Organs of Sense in the Salmon .............+. anepdnwes M. ScuomsurckK on the various Modes of Fishing employed by Indians in the West of Guiana ..........scecececececececncscecececeescenssseerecseseees Mr. James WILson on some Persian Insects .......+2+++++seeee Sue nsewseun Mr. Joun Goopsir and Mr. E. Fores on Pelonaia, a new genus of Ascidian Mollusca .......sccscecessssscsecececncnscscseescsescsseesscnseeuesesues Sir Jonn G. Datyewu on the Regeneration of Lost Organs discharging the Functions of the Head and Viscera, by the Holothuria and Am- phitrite, two Marine Ambirigls "s.cccenatieeessascacencecacdsaane aden eeaaeeeee Mr. Epwarp Forsss and Mr. Joun Goopsir’s further Researches on the British Ciliograda .......se.s.sececeerecsececcsesceesececeseesecssece sake Mr. R. PATTERSON On Medusa .....cscsececscccccecccececescccceccesctecees ai Professor Acass1z on Animals found in Red Snow .....-.sesseeessenees eae Dr. Epwin LanKEsTER’s Notice of Plants and Animals found in the Sulphureous Waters of Yorkshire ......++.-+++ ce ccccdececesescnsanvesenaves Dr. ALpripcE on the Pollen and Vegetable Impregnation ...... See Dr. A. Burn on the Growth of Cotton in India ........+...++- wisealeelewaee Mr. FEeLKIN on the Growth of Cotton .........esseseeeeees Seuss ccduepeaeenee Dr. G. A. Watxer Arnorr’s Remarks on the Synonyms and Affinities of some South African genera Of Platts .........-sssesesseeeeeseeseneeeeees Professor Ross on an Anomalous Form of the Plum, observed in the Gardens of New Brunswick ..........+- aut To cn ubite's oadexdtesecnosssnquneueeee MEDICAL SCIENCE. Dr. ALLEN THomson’s Account of some new Observations on the Struc- ture of the Gastro-intestinal Mucous Membrane, and more particu- larly of the Gastric and Intestinal Glands .......-..--++ aeeeeeeeet a mesenne Dr. Joun Rerp on the Manner in which the Vital Actions are arrested in Asphyxia ......00 doscssesbsossntosses soe tosapeb sucsscccebassearecsiesner enodas Page 149 ————> 2. SC CONTENTS. Dr. Joun Rerp on the Anatomical relation of the Blood-vessels of the Mother to those of the Foetus in the Human Species........0-.seeeseeese on the Anatomy of the Medulla Oblongata ............... Dr. Sym on the Mechanical Functions of the Har .........seseceseseeesenees Dr. Joun Rerp on the Connection between the Netvotts System and Mascular Contractility .......... Beate maa nae gnc ceeecteccersescrecseecss _ Mr. Georce Grover on Foreign Bodies in n the Chigalinene Sepaseagaeas Dr. BucHannan on Fibrine of Human Blood .....0..2..2.sececesceeeeees se Dr. N. Fowxer on some of the Functions of the Fifth Pair of Nerves, and of the Ganglia, 8&C..........s.sssceseseessesceseeees Brice sera yaaa scnises Dr. Rzzs on the Preservation of Subjects for Anatomical purposes...... Dr. Jerrreys on the Uses of the Conglobate Glands .,......sssssseeeeee Dr. Patrick Newsieein on the Therapeutic Effect of Croton Oil in certain Nervous Disorders ......0... ssscsecesssenseeeres SALLE SERRS SEARS Aas Dr. J. R. Cormack on the Effects of Air when, Injected into the Veins Dr. MAacDoNa nD on Mnemonics......csseecesececeecrsoecnscesescsecescrcaee Dr. R..M. Guover on the Physiological and Medicinal Action of Bro- Mine and its Compounds ......ceccececeecesceccrsccsscnnerecsecceesereeeseene Dr. Hannan on the Treatment of Pertussis by Cold washing of the Chest Dr. Perry on the Circumstances which govern Local Inflammation, the effusion of Coagulable Lymph, and the formation of Pus, as the Se- - quel of Disease, Accidents, Surgical Operations, &c. ...........-0+00s. ‘Dr. Macxay on the Chemical and Medicinal Properties of the Matias Bark, which is employed in EEN South America, as a substi- Putte Por, Cimchona 23.08 dark senvauevaascesecinavedcendisertyvescses ascccevecass Dr. Perry on the Laws which govern Contagious Fevers, the circum- stances which favour their diffusion, and the mode by which they are communicated from one individual to another .........ceecsseseeseseeseee Dr. Cuartes W. Beuu’s Notice of the Disease known by the name of Malad? Aleppe..iasscaste gens .S-ceveseccqesrtseessne dueanencaes dadaagiataresns Ao Mr. A, Ure on the Operation for ‘Squinting Ruane saneeeaaeiiated Sunsnsent ats Mr. K. Macxay’s Description of a double Monocephalic Human Mon- ster, which was transmitted to this country from South America .. Dr. Lawrie on the Results of Amputations .......0.cscesccessssenseenecees Dr.R. D. THomson on Opacity of the Cornea produced by Sulphuric Acid Dr. H. Lonspaux’s Notice of an Ossified Tendo Achillis, and of a Case Bi PRGSCOSIS: Sati 0csescacseeetu auc ndansd2iSscne5e- 0s cdacdins ashe spouses captedats Mr. James Dovetason Dislocation of the Ankle-joint forward and back- ward ; and on the Reproduction of Bone after the Operation of Trepan Mr. Joun Dunn on the Vital Statistics of Scarborough .................. STATISTICS. Captain Mrixar on the State of Crime within Glasgow and City Police Jurisdiction .........066 sae tFe sine euks erick ndesaue penwacse steams: bucseouseatae Mr. Leapserrer on the Normal School of Glasgow dei BAe Ase sere Mr. Auston on the Glasgow Asylum for the Blind .....0....ssscessseesees Captain Mitiar’s Comparative View of the State of Crime in : London, Dublin, and Glasgow ......... eevees Mr. Warr on the comparative Vital Statistics of Edinburgh and Glasgow Dr. Cowan on the Vital Statistics of Glasgow ............+ Sisbinaly tone sen Dr. CLevanp on the cee. Trade and Commerce of the City of Glasgow ........c.cc0eeee Gods tgaet eedehaien sped vivindiie heeds snecphcteddecsebvere vil Page 153 154 154 155 155 156 156 156 156 156 157 157 157 158 159 160 160 161 163 163 163 164 165 165 167 169 170 171 173 173 173 viii CONTENTS. Mr. RuTuErG Len on the State of Crime within the Suburban Di- PONG tases Nee ASR owes nese crac enna ne roeanaesane= aaceeser tonne sare naneeretes Mr. Frxpiater on the State of Crime in the Suburban Burgh of PRC ERIS eit tenon one ian saawelanecuast ganna: nade onrnaraaaaeer dammnemenen eee Mr. RicHarpson on the State of Crime in ‘the District ‘of Gorbals “E02 The -MancHEsTER Statistical Society on the State of Education in the Borough of Kingston-upon-Hull .........sssseeseeeeeereceeeeseeeneeees Mr: Porter on Pawnbroking in Ireland, and on the beneficial results which had followed from the establishment of a Mont de Piété, in connexion with a Loan Fund, at Tanderagee ............csessceeeeeeee Mase Mr. Leatuam on the Bill Circulation of Great Britain .............e0e++- Mr. JosrpH BentLey on the State of Education and Crime in England ani WV dlespenseenetasaee eoncresdecnecnteccscascaesecersnscarscecensceressa=nmeenee Dr. CuaLMeErs on the Application of Statistics to Moral and CEconomic LIGNE ae -ks semaanceaen «Saw tee Sees dean shinina stones Sanne ecedshaescss a aeauneriame = —————— on the Pauperism of Glasgow ...........sesceececenseeeceeees Dr. Avison’s Illustrations of the Practical Operations of the Scottish System of the Management of the Poor .............00..scescsseseeseeecers Dr. Atcorn on the excess of Population, and on Emigration as a Remedy for it, in the Highlands of Scotland ...............ssseeceseeeeees Mr. Witson on the Population of Scotland .........scecseecseesecerereceees Professor ApRtAN on the Libraries of Germany ............ssseeeeeees camaiss Rev. P. Caatmers on the Parish of Dunfermline ..............008 Sedge MECHANICAL SCIENCE. Mr. J. Scorr RussEevu on the Temperature of most effective conden- Ration iH Steam VeSSCls Seeks -<6seganeeonotesh teasececcsassaravas~ aeaeeneeanee Additional Notice concerning the most Econo- mical and Effective Proportion of Engine Power to the Tonnage of the Hull in Steam Vessels, and more especially in those designed for long Voyages «.....ccccececesecccccaccscenecscscosccccorencescnecscncroucscasccsesences Dr. Wiit1am WaLtiace’s Notice of Properties of the Catenary and Curves of Equilibration, with Tables for their Construction, contained in a Memoir entitled, “‘The Parallelogram Forces and Curves of Equilibration ; together with Tables for their Construction, deduced froma Functional’ Equation 2.5. 05i505c.60cc 522 cecsdscanscevesecessecnnoanees Rev. J. Broprz on a New Mode of Propelling Fluids, or an uniformly Propelling Wheel .........-sscsssescccssccscssocssccecscceveccescosssccees a8 Dr. Far@uHarson on the Strongest form of Sea-borne Vessels ......... Professor Gorpon on the Turbine Water-wheel .............2seeeeeeeeeees Mr. Josep WuitwortH on producing True Planes or Surfaces on Metals...5........00: cossne ees ae Se eee nee Mr. Vienotes on the Giconomy of Railways in respect of Gradients Mr. Wat ace on Extinguishing Fire in Steam Vessels ....... Beenatens wee Mr. Vienoxes on Timber Bridges of a large size, in special reference to Railways ..-.cccccccecesesse cocnsccsceccecees cecesceee ccersccsascccnccscscscnsnce Mr. Hawkins on the Safety Rotation Railway......cccscsccscscscsssereees - Mr. Mircuext on Timber Bridges, with reference to their Application to the ceconomical construction of Railways ...+.ssssecsessscserssersceeee Captain E. J. Jounson on the co wae: of Native Alloy for Com- Pass PivOts ...cssecseeeeceeeeereesereeenerenees Sota sokewancocsesseouesepuscet Mr. FarrBAIRN on the Fan- Blast as “applied to Furnaces sececcscccccess 186 188 190 190 191 191 192 193 194 195 196 197 198 199 ——— = ee Pa ee. — =e CONTENTS. Mr. Wituiams on the Combustion of Coal, and the Prevention of the Generation of Smoke in Furnaces ............++. sah aaeenetesdngenansee+cas6 Mr. Farrsarrn’s Experimental Inquiry into the Strength of Iron with respect to its Application as a substitute for Wood in Ship-building Mr. Eaton Hopex1nson’s Experimental Researches into the Strength of Pillars of Cast Iron, and other Materials ....... asseduderessecsasceusess Mr. Loruian on a Revolving Balance ....... scanesweaoeauaeed Eottecneusesesese Mr. Tuom on a Water Filter .4.......ece0e. Saaeeemaseae ies te Saeena ssa easaeve Mr. Watcvace on a Smoke Protector ......sssessescessescecsecsees ed eelaans Mr. Marrutas Dunn on an Improved Working Barrel for use in PARMA MEALS OUCa's ssa dos cece den sdadesdspstesece ese oieopsassesanOesaiouerescuntcant Mr. Rayners on a Machine Regulator ........ssscesecseeceeceeseneeeceneees Mr. Suiru on the Drainage of Railway Embankments and Slopes ...... on Timber Bridges......... ARC Roghgpsnesdh sone. soenidartnccbosoate on Propelling Boats on Canals ..........2.00+0+ aed cauerereraree nee Mr. J. Hawkins on Mr. Bakewell’s Anglemeter ..........cseceseceeseneeee Mr. Smitu on a New Canal Lock ............20000 sudduiteaneranavececencge Mr. Farrparrn on Raising Water from Low Lands..............-sseeee00 Mr. Tuom on an Improved Rain Gauge......... Biase Ceapware cas scese re doses Mr. James Jounston on a New Rain Gauge ..........2+00 spsibstehodeec: Rey. Dr. Paterson on an Improved Life-Boat .........scessesersesseeeeeeee Mr. Hawruorn on certain Improvements on Locomotive and other Engine Boilers .........s000..- Beesare eee ee Nap encase our osea anv acaens swace eae Mr. Grime on Wrought Iron Wheels for Locomotive Engines ......... Mr. Dircxs’s account of a Railway Wheel with Wood Tyre ......... eee Mr. Coxzs on a new Step-Rail, and Railway re Sure Scognag ee Mr. Lane on an Improvement on the Air Pump ...-..cssesecsseeeees densa Mr. Guuuine on Safety-Valves for Steam Boilers.............:esseeesseees Mr. James Mine on a Gas Regulator ......... peadenaa= Souseeeienee =p Senses Mr. JEFFREY ona new Hydraulic Apparatus ......ssceseeee BRP SE Reson ASE Mr. Ritcuiz on Warming and Ventilating Buildings .........00.+ssse000 Mr, Grime on Dennett’s Rockets for preserving Lives from Shipwreck ix Page 199 201 202 206 207 208 208 209 209 209 209 210 210 210 210 211 211 211 212 212 212 212 213 213 213 214 214 \ +4 om 7": ¥ aT fay ay Mi Aaa day TNL AE arg bb el ; ; fi hcg 7 a "Yai dee tir j BS, Peabo quip. CREE: side Pa Ot ee FeO, Fic es LF « = Win SV OSE Now Su ba OF h oa es 8 Bpapelhae alee? oN he par tga cucas i iv You ¥ pets e8-3° 2 ee ; . he a th « eR deletes tie Ye thine ae Cuvee Pe eS GAR ete S 4 { a ee ar Avec nisuelinks Pa hie Pine 4 ‘ oe Pi re a Yue + marys reef 7 rates s : « | ati Seis oz La SD : sa Pee De i, Pee RE. ERS ie hrc ae NOTICES AND ABSTRACTS OF MISCELLANEOUS COMMUNICATIONS TO THE SECTIONS. MA'THEMATICS AND PHYSICS. On the mean Apsidal Angle of the Moon's Orbit. By Dr. Forzss. By limiting the terms in the expression of the integral equation to the first four, viz. those depending on cosc @ — a,cos20—2m042(,cos20—2m0+2B—Oc+a or the evection, and cos 26—2m6+4% + cv — a, he derived the number expressing the ratio of the apsidal angle to the whole circle, and found it to be 00843; the result given in the Mécanique Céleste, by Laplace, being the same. A decided influence was ascribed to the inclination of the moon’s orbit to the ecliptic, and the corrections that require to be made for it; also, to the value due to h, or the space described by the radius vector in the unit of time, in the disturbed orbit, compared with the same in the simple elliptic theory. The circum- stance that this quantity may be so easily determined presents a beau- _ tiful evidence of the law of gravitation, and of the truth of the New- _ tonian theory, and may ‘be of material importance in the theory of the moon. An Account of the Observatory erecting near Glasgow. By Professor NICHOL. He stated that when he was appointed to the office he holds in the University, the state of the Macfarlan Observatory gave him much anx- iety, as in consequence of its age it was in nowise fitted to be of service 1840. B 2 REPORT—1840. to astronomical science, nor did its site encourage any attempt to repair it; but the strong desire existing both in the College and among the citizens of Glasgow for the erection of a suitable establishment, speedily relieved his embarrassment, and by the union of the two parties and the patronage of Government, means were soon provided to accomplish all good ends. The Professor then adverted at some length to the principles on which the plan of the Institution was arranged. It was his strong conviction, that although the repetition of the same observa- tions at different observatories was to a certain extent necessary for the elimination of errors, this had been much overdone, and time and labour thereby lost. He was strengthened by the opinion of all the eminent men with whom he corresponded, in his resolution not to enter in Glas- gow on the line pursued with such brilliant success at Greenwich, Edin- burgh, Armagh, &c., but to devote the new observatory to investiga- tions which lay for the most part out of the way of these other establish- ments, and which in the present state of astronomy are numerous and important. It was a first point with him therefore to see to the provi- sion of an efficient equatorial, and, if easily attainable, a large reflector. Circumstances had hitherto prevented the completion of the arrange- ments in reference to the equatorial, but these would soon be over- come, and he could venture to promise an instrument of this kind of first-rate power. He had obtained almost by accident two reflectors, by Ramage, one of 25 focal feet length, to which he meant to affix Sir John Herschel’s collimator, and another of 55 feet in length and 23 inches diameter. This one was fit only for occasional observations, and he did not in the mean time intend to attempt to give it more than a mere meridional sweep. But although the instruments now referred to may be the ones chiefly used in the researches to which the observatory will in the first instance be devoted, a good meridian instrument was clearly necessary, inasmuch as several of the inquiries about to en- gage them depended upon the nicest determinations of this descrip- tion. Accordingly, urged by the feeling that in so far as they could go, every department of the institution should be equipped in the best style, they ordered from Munich a transit circle, the telescope of which is 8 feet focal length, and 64 inches diameter. The Professor described this instrument at length from diagrams. He called particular attention to the fact that it read by microscopes, and that as the circle carrying the microscopes was not in the same place as the circle with the graduated limb, the objection having reference to the hazard from traction, forcibly urged by Professor Airy, was entirely obviated. The Professor then stated that a magnetical observatory, with the three in- struments, at which Gauss’s terms would be noted, was meant to be attached to the other establishment, and that he hoped tobe able to pay attention to some of the more important problems in meteorology. He could not promise success, but this he could well promise, that his life should be thoroughly and singly devoted—now that the means were in his power—to the realization of objects of importance to astro- nomy. TRANSACTIONS OF THE SECTIONS. 3 On a New Apparent Polarity of Light. By the AsTRONOMER RoyAL. Sir David Brewster had, at the Liverpool and Newcastle Meetings, stated a most extraordinary fact respecting the solar spectrum or coloured image formed by the agency of a prism, when viewed through thin plates of glass or mica. Most members of the Section were aware, but to some it might be new, that the light in the solar spectrum could be so managed as to be entirely free from all mutual intermixture or jumble of different colours. When this was done, suppose this pure spectrum to be so turned as that its violet end lay to the right hand and the red end towards the left, and suppose the pupil of the eye to be half covered by a thin piece of glass or mica—if the piece of glass or mica be made to cover that half of the pupil which is towards the violet end of the spectrum, numerous parallel bands are seen to cross the spec- trum. This fact was long since observed by Mr. Talbot; but the extraordinary fact observed by Sir D. Brewster was, that upon turning the plate of mica so as to cover the half of the pupil next the red end of the spectrum, all the bands completely disappeared. This fact ap- peared so inexplicable to Sir David Brewster, that he pronounced it to indicate a new and hitherto unobserved polarity of light. From this opinion he ventured to dissent, and he should endeavour to explain to the Section how complete a solution of the facts was afforded by the undulatory theory of light. But before he proceeded, he must premise that his own experience of the facts differed from that of Sir D. Brews- ter, though so slightly, that the circumstances he deemed material might readily be overlooked. He should only say that he had consulted a friend respecting these discrepancies long before he was aware of their important bearing on the explanation. The peculiarly short- sighted character of his eye, was perhaps the occasion of their beco- ming so perceptible to him. The tacts, as he observed them, were :— 1. When a spectrum is viewed out of focus, bands are formed by pla- cing a piece of mica, of a proper thickness, so as to cover the half of the pupil next the violet end. 2. No bands are formed with any thickness of mica if it be placed on the side of the red end. 3. When the eye is too distant to see the spectrum distinctly, upon moving the mica from the violet end, bands are seen advancing in the same direc- tion over the spectrum. 4. When the eye is too near to see the spec- trum distinctly, the bands appear to move in the opposite direction. 5. If the eye be so far off, and the spectrum is consequently seen so indistinctly, that the ruddy portions are nearly mingled with the blue, upon covering with the mica half the pupil next the violet end, bands are seen well-defined, but narrow. 6. If the eye and mica approach the position of distinct vision of the spectrum, the bands become broader, and near the position of distinct vision sometimes disappear ; on approaching still nearer, the bands re-appear and become narrower, but he thinks are not seen so distinctly as when the eye is too far off (this may, however, depend on the practical difficulty of that part of the experiment). 7. Bands which are visible when the mica is on the violet side, and invisible when it is on the red side, never occur when B2 4 REPORT—1840. the spectrum is pure. 8. Bands are frequently visible when the spec- trum is pure; but in that case they can be seen equally well, whether the mica be placed on the violet or on the red half of the pupil. Mr. Airy then gave a rapid sketch of the leading features of the undulatory theory,—showed how a series of rays or a wave in passing through a convex lens, being more retarded in passing through the middle of the lens than through the edges, was bent so as to be convex to the lens after passing through it, and thus was made to converge to a focus. Next, if a thin plate of a transparent substance, like mica, were made to cover half the lens, one half the waves were retarded; and thus, when the lens represented the eye, and the place of the focus the retina, interference was produced, which, when the distance of the retardation bore a certain relation to the distance of two waves (or the wave length), might obliterate the light altogether. Next, if a lumi- nous point be looked at, it never is seen as a point, but as a small circle of light; and if a retarding plate be interposed, under some circum- stances bands or fringes parallel to the edge of the retarding plate are generated in the circular image of the luminous point; and those bands are not symmetrically arranged from the centre of the circular image; and the amount of their deviation from symmetrical position depends on the retardation of the ray in passing through the plate of mica, &c. and therefore depends upon the colour of the ray, or upon its posi- tion ina spectrum. Thus, if we examine the bands formed by different kinds of light, similar to those from successive points in a spectrum, the bands formed by these different kinds of light will be shifted suc- cessively more and more to the right (or to the left as the case may be). Now, if different luminous points be superimposed (as suppose points of the different coloured lights contained in white or solar light), in general it would be easily understood that the bands belonging to one colour would fall unsymmetrically between the bands in the circular image of another colour ; and thus if a multitude of them were super- imposed, they would tend to obliterate each other. But if the luminous origins of the different streams of coloured light did not coincide, but were arranged side by side in the same order as the order of their suc- cessive retardations by the mica, (which supposition is exactly repre- sented by supposing the origins to be the successive points of a spec- trum, formed either by refraction or by diffraction,) then it might happen that the shift of the centre of each image, in proceeding from one to the next, was exactly equal to the shift of the bands in relation to the centre of the image; and if this shift took place in the proper direction, the bands formed by the light from the different sources would unite and would strengthen each other; but if the shift took place in the opposite direction, the bands would be more widely sepa- rated than before, and would obliterate each other. It resulted from a mass of calculation to which he had subjected these conditions, that the relation of the wave lengths of the different colours, in passing from the violet to the red end, was such, that, under favourable circum- stances, a retarding plate being made to cover the half of the eye next the violet end, the bands came together, and so strengthened each TRANSACTIONS OF THE SECTIONS. 5 other and became obvious to sense; but on turning the plate to the red end, the bands separated and obliterated each other. Thus the phenomenon became a simple consequence of the undulatory theory. On Professor Powell’s Measures of the Indices of Refraction for the lines G and H in the Spectrum. By Sir Davip BREwsTER. After noticing the discussion between Professor Powell and himself on this subject, the author drew attention to another demonstration of the accuracy of his former statements. In the diagram No. I. he had drawn the group of lines round G, which is a single line well marked in the spectrum, and distinctly delineated in Fraunhofer’s map. ‘The real line G is not situated in the middle of the group, but much nearer its least refrangible side, and hence the index of refraction, as taken by Prof. Powell from the middle of the group, must have a greater index of refraction than the real line G, whose wave length in the interference spectrum had been determined by Fraunhofer. In reference to the line H the error is much more serious, as appeared from the diagram No. IL., in which Sir D. Brewster had represented the two remarkable bands in the violet rays, the least refrangible of which is distinctly marked in Fraunhofer’s map with the letter H. Between the central lines of these two bands there are no fewer than fourteen lines in the same map. All the observations made by Fraunhofer, both on the camera spectrum and the interference spectrum, apply to the central line H of the least refrangible of the two bands; but the observations of Prof. Powell, to which the author referred at the Newcastle Meeting, were all taken from an imaginary line bisecting the interval between these two bands, and therefore were of no value as physical data for testing the new theory of dispersion. Prof. Powell has recently given new measures for the real lines G and H, thus admitting the accuracy of Sir D. Brewster's former observations. On the Decomposition of Glass. By Sir Davip BREwsTER. The author has had occasion to examine the phenomena of de- composed glass, both of that which is found in Italy, of which he has received the finest specimens from Dr. Buckland and the Mar- quis of Northampton, and of other specimens recently found in making excavations among the ruins of the chapter-house of the cathedral of St. Andrew’s. In decomposed glass the decomposition commences in points, and extends itself either in planes so as to form thin films, or in concentric coats so as to form concentric films. When the centres of decomposition are near each other, the concen- trie films or strata which they form interfere with each other, or ra- ther unite, and the effect of this is that the glass is decomposed in films of considerable irregularity, their surfaces having a finely mammillated appearance, convex on one side and concave on the other. The films 6 REPORT—1840. thus formed are of extreme beauty, and afford by transmitted light co- lours of infinite beauty and variety, surpassing anything produced in works of art. They have the effect of directing, as it were, the com- pound surface of the solar spectrum, or of sifting and separating the superimposed colours, in a manner analogous to what is produced by colours and absorbing media. Sir D. Brewster has succeeded indeed in producing one or more bands of white light incapable of decompo- sition by the prism, and there can be no doubt that they will be found to exercise a similar or an analogous action on the heating rings of the thermometric spectrum. In the decomposed glass from St. Andrew's a change of a very different kind is effected. In some cases the sili- ceous and the metallic elements of the glass are separated in a very sin- gular manner, the particles of silex having released themselves from the state of constraint produced by fusion and subsequent cooling, and ar- ranged themselves circularly round the centre of decomposition ; while the metallic particles, which are opake, had done the same thing in cir- cles alternating with the circles of the siliceous particles. This restora- tion of the silex to its crystalline state is proved by its giving the co- lour of polarized light, and possessing an axis of double refraction. The preceding notice was illustrated by diagrams and specimens of the different kinds of glass referred to. On the Rings of Polarized Light produced in specimens of Decomposed Glass. By Sir Davip BRewsTER. In the course of a series of experiments on the connexion between the absorption of light and the colours of thin plates, published in the Phil. Trans., 1837, the author accidentally observed under the polar- izing microscope certain phenomena of polarized tints, of great beauty and singularity. These tints were sometimes linear and sometimes cir- cular, and in some specimens they formed beautiful circular rings, tra- versed by a black cross, resembling the phenomena of mineral crystals, or those produced by rapidly cooled circular plates or cylinders of glass. Having found in the decomposed glass from St. Andrew's that the sili- ceous particles had resumed their position as regular crystals, and ar- ranged themselves circularly round the centre of decomposition, he was led to suppose that this was the cause of the phenomena, and that the rings were the effect of the double refraction of the minute cry- stals. A few experiments, however, overturned this hypothesis, and he was soon satisfied, by a little further investigation, that the phenomena arose wholly from the polarization of the transmitted light by refrac- tion, the splendid colours being entirely those of thin plates, which were sometimes arranged so as to have the appearance of concentric rings. The structure by which these effects were produced was com- pared by the author to a heap of very deep watch-glasses laid one above another. When the thin films were arranged longitudinally, and were inclined to the general surface of the plate, so as to transmit the rays ob- liquely, the light was still polarized, but only in one plane, namely, a TRANSACTIONS OF THE SECTIONS. 7 plane perpendicular to the plane of incidence. When a drop of water or oil was introduced between the films, the phenomena of polarization, as well as of colour, instantly disappeared. The preceding paper was illustrated by coloured drawings. On the Cause of the Increase of Colour by the Inversion of the Head. By Sir Daviv Brewster. “Tt has been long known to artists and tourists that the colours of ex- ternal objects, and particularly of natural scenery, are greatly aug- mented by viewing them with the head bent down and looking back- wards between the feet, that is, by the inversion of the head. The co- lour of the western sky and the blue and purple tints of distant moun- tain scenery are thus beautifully developed. The position of the head, however, which I have described, is a very inconvenient one, but the ef- fect may be produced nearly to the same extent by inverting the head so far as to look at landscapes backwards beneath the thighs or under theleft arm. It is not easy to describe in any precise language the degree of in- crease which the colours of natural scenery thus receive, but an idea may be formed of it from the fact, that the colours of distant mountains which appear to me asif of a French-gray colour when viewed with the head erect, appear of a brilliant blue or purple tint with the head inverted. Upon inverting the landscape by reflexion I found that no increase of colour took place. Ithen viewed the inverted landscape with the head inverted and found the colour to be increased as before. Hence it ap- pears that the increase of colour is not owing to the simple inversion of the object and to our viewing it under unusual circumstances. That the augmentation of tint is not owing to the impression falling upon a part of the retina not so much accustomed to receive such impressions, is obvious from the fact that the tint is the same upon whatever part of the retina the image falls, and it is easy to see that the very same part of the retina is affected whether we look at an object with the head up- wards or downwards, or in any other position, provided we look at it directly. In order to acquire some information on this subject, I re- quested a friend who was unacquainted with any theoretical views that had been advanced, to make some observations on the change of colour of distant mountains. The result of these was to convince him that the increase of tint arose from the protection of the eye from lateral light, owing to the position of the head when inverted. On submitting this opinion to examination, I found that the tint was not increased by protecting the eye from lateral rays, even to a much greater extent than is done by the inversion or inclination of the head, and therefore that this could not be the cause of the increase of colour. In this perplexity about the cause of the phenomenon in question, I had an opportunity of observing the great increase of light which took place in an eye in a state of inflammation. This increase was such that objects seen by the sound eye appeared as if illuminated by twilight, while those seen by the inflamed eye seemed as if they were illuminated by the direct rays 8 REPORT——1840. of the sun. All coloured objects had the intensity of their colours proportionably augmented, and I was thus led to believe that the in- crease of colour produced by the partial or total inversion of the head arose from the increased quantity of blood thrown into the vessels of the eye-ball,— the increased pressure thus produced upon the retina, caused from the increased sensibility thus given to the vertical membrane. Subsequent observations have confirmed this opinion; and though I cannot pretend to have demonstrated it, I have no hesitation in ex- pressing it as my conviction that the apparent increase of tint to which I have referred is not an optical but a physiological phenomenon. If this is the case, we are furnished with a principle which may enable us not only to appreciate faint tints which cannot otherwise be recognized ; but to perceive small objects, which, with our best telescopes, might be otherwise invisible.” ————- —_———- On the Phenomena and Cause of Musce Volitantes. By Sir Davip BREWSTER. The following are the principal results described in detail in this communication.—1. That in persons of all ages, and with the most perfect eye, transparent filaments or tubes exist in the vitreous humour, and at different distances from the retina. 2. That these filaments float in the vitreous humour, moving about with the mo- tion of the head. 3. That these filaments are seen by means of their shadows on the retina, and are most distinctly visible in diver- gent light, their shadows being bounded by fringes produced by dif- fraction or inflexion. 4. That the real musce, resembling flies, are knots tied, as it were, on these filaments, and arising from sudden jerks or motions of the head, which cause the long floating filaments to overtop and run into knots. 5. By making experiments with the head in all positions, and determining the limits of the motions of the musce, by measuring their apparent magnitude, and producing double images of them by means of two centres of divergent light, the author was able to determine their exact place in the vitreous humour, and to ascertain the important fact, that the vitreous humour in the living human eye is contained in cells of limited magnitude, which prevent any bodies which they contain from passing into any of the adjacent cells. Sir David Brewster concluded with the following observations. “JT have dwelt thus Jong on the subject of Musce volitantes, not only because it is an entirely new one, but also on account of its prac- tical utility. Myr. Mackenzie informs us that few symptoms prove so alarming to persons of a nervous habit or constitution as Musce volitantes, and that they immediately suppose that they are about to lose their sight by cataract or amaurosis. The details which I have submitted to you prove that the Musce volitantes have no connexion with either of these diseases, and are altogether harmless. This valu- able result has been deduced from a recondite property of divergent light, which has only been developed in our own day, and which might TRANSACTIONS OF THE SECTIONS. 9 seem to have no bearing whatever of an utilitarian character. And this is but one of numerous proofs which the progress of knowledge is daily accumulating, that the most abstract, and apparently transcendent truths in physical science will sooner or later add their tribute to supply human wants and alleviate human sufferings. Nor has science per- formed one of the least important of her functions, when she enables us, either in our own case or in that of others, to dispel those anxieties and fears which are the necessary offspring of ignorance and error.” On the Line of Visible Direction along the Axis of Vision. By Sir Davin BrewsTER. In Monsieur D’Alembert’s Memoir “On Different Questions in Optics,” published in his “‘ Opuscules Mathématiques,” tom. i., he has maintained the singular opinion, that distant objects, like the fixed stars, when viewed directly with both eyes, are not seen in their true direction ; that is, neither in the direction of the rays which they send to the eye, nor of the line (coincident with it) drawn from the point of incidence in the retina through the centre of visible direction. The author pointed out the fallacy in D’Alembert’s reasoning, and thus established, in opposition to the opinion of that distinguished philoso- pher, the law of visible direction, which he had explained at the New- castle Meeting. A Brief Account of the Camera Obscura, and other Apparatus, used in making Daguerreotype Drawings. By Sir Davip BRrewsTER. The author exhibited a very perfect apparatus, executed for him by Mr. Thomas Davidson of Edinburgh, who has made some essential improvements on the process. Sir David also exhibited several draw- ings taken by Mr. Davidson with that apparatus, of various buildings and scenes in Edinburgh. He likewise explained to the meeting the method of executing Photogenic Drawings on paper, as invented by Mr. Fox Talbot, and exhibited to the Section a series of very beauti- _ ful drawings executed by Mr. Talbot himself, and presented to him by that distinguished philosopher. —— ——____ On a Method of Illuminating Microscopie Objects. By Sir Davip Brewster. Considering a perfect microscope as consisting of two parts, viz. an _ illuminating apparatus, and a magnifying apparatus, the author stated, | that it was of more consequence that the illuminating apparatus should be perfect, than that the magnifying apparatus should be so; and that the essential part of his method consisted in this; that the rays which form the illuminating image or disc shall have their foci exactly on the 10 REPORT—1840. part of the microscopic object to be observed, so that the illuminating rays may radiate, as it were, from the object, as if i¢ were self-luminous. Now this can only be well obtained by illuminating with a singlelens, ora system of lenses, without spherical or chromatic aberration, whose focal length, either real or equivalent, is less than the focal length of the object-glass of the microscope. The smaller the focal length of the illuminating lens or system of lenses, the more completely do we secure the condition that the illuminating rays shall not come to a focus either before they reach the object, or after they have passed it. When Dr. Wollaston recommended for an illuminating lens, one of three-fourths of an inch in focal length, in which the microscopic object was placed in a vortex of foci, where the rays crossed in a thousand points both before and after they fell upon the object, he could have had no idea of the new method of illumination. In the construction of a per- fect microscope, Sir David Brewster recommended that the illumina- ting and magnifying apparatus should have separate and similar move- ments along the same rod or bar, and that the stage for the objects should be unconnected with either, and should have also a motion independent of both. On an Improvement in the Polarizing Microscope. By Sir Davip Brewster. This improvement consists in placing the analysing prism or simple rhomb immediately behind the object-glass, that is, on the side of the object-glass next the eye. The great inconvenience of placing it be- tween the eye-glass and the eye, had induced several skilful observers to reject the prism altogether as an analyser, or to substitute for it a plate of tourmaline, which is quite unfit for any observations in which colour is to be considered. The analysing prism may remain constantly on the microscope behind the object-glass, without in the least injuring the performance of the microscope, and it should have a motion of | rotation independent of the body of the microscope. Extract of a Letter from Col. Rei to Sir D. Brewster. Bermuda, August 17th, 1839. Dear Sir,—I think the accompanying letter, which describes the singular ap- pearance of the sun at Bermuda, which made white objects appear blue, cannot | fail to interest you; and if you are able to explain the cause of this, I should | be very glad if you would favour me with such explanation. The fact is one | familiar to every one here; but I requested Dr. Harvey to put it in writing, / expressing what he saw himself, that I might send the account to you. The present collector of the customs at Bermuda was at sea on the 11th of August, the | day the same hurricane was passing over St. Vincent; and to him and to the | other persons on board, objects appeared, they thought, of a light green or bluish green colour, and the sun had this same appearance. Their vessel was | then fifteen miles east of Bermuda. ‘The hurricane reached Barbadoes a little | before midnight on the 10th of August, 1831. / ‘ TRANSACTIONS OF THE SECTIONS. ll Three days ago I had a fine opportunity of observing a waterspout under my house, and could, with a spy-glass, distinctly observe that, at the surface of the sea, it was revolving like the hands of a watch, and the same observation was made at a telegraph station near Government House. This is the fifth account, well authenticated, in north latitude : all five revolved in the same way. Bermuda, 5rd August, 1839. Dear Si1r,—Not having made any notes at the time, I can only proceed to narrate the circumstances, which occurred here in August, 1831, from memory. On the 10th of that month the weather was remarkably fair, but as evening drew near a change took place. The sky began to lower and put on an awful aud gloomy appearance. The clouds collected voluminously and very heavily in every direction over the island, indicating a prodigious fall of rain. At this time I do not recollect any threatening of a storm of wind, save a moderately hollow sound of the sea dashing against the shore, but by no means equalling that which we frequently witness at this season of the year when a storm is impending, or has passed by us. ‘Thunder and lightning began to be severe, and the weather more threatening. Next morning, the I1th, I rose early, for the purpose of writing, and soon discovered, the light was so dim, I could not proceed. I removed to another room, and finding my situation not improved, I said in the presence of one of my family, I apprehend a sudden fuilure of sight. I was then asked if I had not observed a very peculiar appearance of the sun’s rays the day before. 1 had not; but had perceived the floor of the room to look blue, especially where the sun shone on it: indeed every object in the room appeared of a sickly blue colour. The next day, the 12th, a mail- boat was put under weigh for the first time, with a party on board. The day was so mild and tranquil we could only reach a few miles; the sails, which were new, and pure white, nevertheless appeared to be stained of a bluish colour, and the sea was of a dingy yellow. On the first arrival from the West Indies we heard of the devastation at Barbadoes; but with us there were no subsequent unusual appearances; on the contrary, we had very fair weather, although I heard this singular blue colour was observed even to the coast of America. (Signed) Avueustus Wm. Harvey, M.D. Sir David Brewster, who communicated Col. Reid’s letter, observed, that in the course of a series of experiments on the colour of mixed plates, both as produced by the soft solids compressed between plates of glass, and as exhibited in laminz of sulphate of lime, and other minerals containing strata of minute cavities filled with fluids, he was led to the opinion that the blue colour of the sun was produced in a similar way by vapour or water in a vesicular state, interposed between _ the sun and the observer. Owing to this cause, the sun may exhibit any colour, and, in point of fact, he had once seen the sun of a bright salmon colour, in which both red and yellow were mixed with the blue. _ A similar effect is often produced when the sun is seen in a cold winter morning through the windows of a carriage covered with hoar frost, or when it is seen through vapour similarly deposited. Sir David referred to observations of his own published in the Phil. Trans. for 1837, in which he had shown that the colours of mixed plates were phenomena of diffraction produced by the edges of transparent bodies separating media of different density. 12 REPORT—1840. On a remarkable Rainbow observed by Mr. Bowman. Communicated by Sir Davip BRewsTER. “ On Tuesday morning last, soon after sunrise, as the ‘ Commodore’ steamer, from Liverpool, was making her way up the estuary of the Clyde, a very perfect and brilliant rainbow was observed by the pas- sengers on deck, accompanied by a larger outer bow, with fainter re- versed colours, as is not very unusual under the ordinary conditions of rain and sunshine. Nearly in contact with the inner edge of the brighter, or primary bow, were four distinct though smaller ones, parallel to and equidistant from each other, not perfectly continuous, but formed of interrupted segments of circles, the colours of each diminishing in in- tensity, the faintest being the innermost. In all these minor bows the red and orange were the only colours that were distinctly seen. ‘The water being smooth, the reflexion from its surface was so strong that the normal and secondary bows seemed to be continued below the ho- rizontal line, bending inwards till they almost met and formed nearly~ two complete concentric circles, the reflected images being scarcely less brilliant than the bows themselves. The rain drops were few, though larger than ordinary, and the reflected image of the sun ap- peared as a broad band of light on the smooth surface of the water, scarcely less dazzling to the eye than his direct rays. (Above the sun was a canopy of dark cloud, whose lower margin nearly touched his upper limb, and was parallel to the horizon.) I first observed a faint perpendicular light on the north side of the primary bow, and apparently in contact with its outer margin, and as though diverging from it in a tangent. By degrees this shot up higher, and acquired the prismatic colours, which were clearly in the same order as in the primary bow, though fainter. Shortly afterwards a similar tangent was seen on the opposite side, in all respects corresponding, both extending upwards to about the height of the large outer bow. My friend Dr. Black, of Manchester, who was present, first suggested that the lengthened image of the sun upon the smooth water might probably produce these up- right lateral columns, the image in this case acting the part of the lu- minary himself. We had soon an opportunity of testing the soundness of this solution, for in a little time the upper limb of the sun came in contact with the lower edge of the cloud, and as he very gradually dis- appeared behind it the primary bow became fainter and fainter, till at length it faded entirely away. But the upright lateral columns re- mained, nay, for a short time appeared brighter and higher, and only disappeared when the more complete obscuration of the sun destroyed the reflexion of his light upon the water.” On remarkable Rainbows. By the Rev. J. Fisuzr, M.A., of Rosebank, Dumfries. The observations were made on Monday, Ist of June, 1840, while travelling by the coach from Glencairn Manse to Dumfries, nearly at sunset (8 Pp. M.), the sun being bright and the sky only very partially TRANSACTIONS OF THE SECTIONS. 13 clouded. “At first (observes the author), as we were passing over an elevated part of the road, Killness, near New Bridge, a beautiful rainbow was formed, remarkable for the width of its span, the elevation of its arch, as the sun was then low, and also for its vivid colours; still, as the sky became more overcast, the brilliancy of this primary bow increased, and forthwith an upper bow also assumed distinct- ness, and though the colours were indeed inverted, as having un- dergone a double refraction and reflection, was almost as bright as the under bow, and besides seemed more remote from it than I had observed before in the formation of the two bows. No sooner were these two distinctly formed, than a supplementary bow began to form to each. But the phenomenon did not end here; for hardly had these supplementary bows been formed, when there appeared within the arch of the under bow, another, and another, and another, and so on toa fifth, in rapid succession; there being now no less than five supple- mentary bows clearly and distinctly formed; and in one part, particu- larly where the shower above alluded to had been, though the rain had then seemed almost to cease, I could trace the incipient stage of another supplementary bow, but this only for a short space. The others, how- ever, were distinctly formed throughout the whole arch, and the four first especially, nearly as vivid as the under bow itself. “Such was the appearance with regard to the under bow; but upon reviewing the upper one, not only was there the first supplementary bow, but also two others, clearly and distinctly formed throughout the whole arch, and only diminished, as to size, distance, and vividness of colours, as in the case of the first lower bows; only the spaces between each sup- plementary bow belonging to the upper one, seemed larger than between _ the supplementary bows belonging to the under one. And as in the case of the under bow, its supplementary bows gradually diminished as to the size of the arch and brightness of their colours, in a distinct ma- thematical proportion; so also with regard to the upper bow, its sup- plementary bows, vice versd, though they exhibited the exact arrange- ment of prismatic colours, as did the primary bow to which they be- longed, increased their arch over the heavens, diminishing at the same time in width or distance from each other, as well as in the brilliancy of their colours, in the same exact proportion. This whole phenomenon, with ten distinct rainbows, and at one time part of the eleventh, stretch- ing across the heavens, was indeed truly magnificent, and besides, took in a much larger space than I had ever noticed before. The vale of Nith may extend about nine or ten miles across, and in the case of these bows, the one foot seemed near the Barhill, Inwald, and the other near the White hill, Terregles. They first became visible as we were crossing Killness, Ness, Holywood, and continued for nearly a mile without much sensible alteration, only the arches ascending higher and higher (till we arrived at Newton Lodge) as the sun descended. As we ap- proached Dumfries some of the bows gradually disappeared, probably from our having moved out of the proper angle of reflexion. Soon after this the sun sunk below our sensible horizon, and finally showed only the upper part of the larger arches.” / 14 REPORT—1840. On a new case of Interference. By A. BEL. On the Iriscope. By Josern Reap, M.D. After noticing the fact of the appearance of colours on plain glass which has been washed and then breathed on, while breathing on the same glass when perfectly dry yield only a gray vapour, the author describes the following experiment. “ Having procured a convex plate of black glass, such as that of a perspective mirror, I smeared its surface with the top of my finger, dipt in a strong solution of Castile soap and distilled water; when dry I polished with a coarse towel until no clouds appeared ; I now breathed on it through a glass tube about a foot long and one-third of an inch diameter, when a beautiful series of concentric and variously coloured rings were formed.” The author then notices the analogy of the coloured rings thus ob- tained with those of Nobili, procured by voltaic agency, and offers remarks on the theory of the subject. An instrument constructed for the purpose of experiment was exhibited. On an Experiment of Interference. By Prof. Powerit. The author refers to an experiment of Mr. Potter (in the Lond. and Edinb. Journ. of Science, May 1840,) in which, under certain pe- culiar conditions, the central stripe appears black, instead of white, as required by theory, and in the ordinary form of the experiment. The author repeated the experiment in the peculiar way proposed, but still found the stripe in question white. His object was to bring it under the notice of the Section, and induce others to examine the question, especially by micrometrical measurements. On a point in the Wave-Theory as applied to Heat. By Prof. PowEtt. According to M. Cauchy’s theory, the relation between the refract- ive index and the wave-length is expressed by the formula 1 rAx|? wAx | 4 eae eee ey y | and when A is very great, compared with Az, this expression is reduced to its limiting value, | her —=P of, p= TE This forms the limit of refraction for rays of all wave-lengths, whe- ther of light or of heat. And as the value approaches this limit, consi- derable changes in A will correspond only to small changes in p. This deduction is obvious, and has been before made. The limit is easily determined from Mr. Kelland’s calculation for all the media ex- amined by Fraunhofer ; thus e. g. for flint-glass, No. 13, we have FortherayB . . . . ¢B = 16277 For the limit. . . . . go =1°6090 TRANSACTIONS OF THE SECTIONS. 15 The present object is to remark the bearing of this point on the theory of heat. If this theory be true, all refraction of heat ought to fall within this limit, and probably a considerable portion of the heat- ing rays would have an index not far removed from it. It will be parti- cularly interesting to calculate it for rock-salt, and other diathermanous media, and compare it with the index of the heating rays. The data for rock-salt are given in Professor Powell’s report on Refractive In- dices, British Association Reports, 1839. This consideration also explains a difficulty which occurred to Prof. Forbes, who in his Third Series of Researches (§ 2. No. 45—46), having arrived at the conclusion that a wave of heat has a length nearly three times that of red light, regards this as a startling inference, and difficult to reconcile with the small difference existing between the in- dex of refraction for heat and for light. This is just what should re- sult in the above theory. On the Conduction of Heat. By Professor KELLAND. The author’s object in bringing forward this subject at the present time, he explained to be, to point out the state of our experimental knowledge of the transmission of heat, and to exhibit its total inade- quacy to serve as the test of any precise and accurate theory. The following is a brief sketch of the history of the subject. Little had been done before the time of Lambert, who, in 1755, solved one of the most simple problems. Afterwards appeared the writings of Euler. But it was left for Fourier, at the commencement of the present cen- tury, to exhibit a theory having about it the characters of truth, ade- quacy, and extension. For along time Fourier’s memoir was known only to a few, and, as it was based on the Newtonian hypothesis, that radiation is proportional to the difference of the temperatures of the radiating body and of the surrounding air, it happened that the interval which elapsed between its production and its publication, to a great extent destroyed its utility. In 1813 Dulong and Petit, by an admirable series of experiments, established another law, taking the indications of the air thermometer as the measure of temperature. This law is, that the cooling of a body depends, not as Newton sup- posed, on the difference of temperature of the body, and the space into which it cools, but on the difference of exponential functions of the temperatures. The difficulty of the appearance of this law deterred philosophers from attempting its application to any but ove of the pro- blems. This one was that of the ring. M. Libri read, in 1825, to the Institute, and afterwards published at Florence and in Crelle’s Journal in Germany, his analysis of this problem. No one appears to have doubted the accuracy of this solution, until, in 1837, the author ex- pressed his conviction that the whole was founded on an erroneous hypothesis relative to the resulting equation. The following year M. Liouville read a paper on the subject to the Institute, which he subse- quently published in his own journal. In this paper he points out 16 REPORT—1840. clearly the erroneousness of M. Libri’s solution, but does not propose any other in its place. M. Liouville states in a note, that Professor Kelland had preceded him in this matter, and promises to supply a solution. Thus, then, one case of theory appears to be made out. Last year the author again brought forward the subject of Dulong and Petit’s law, but as experiments were wanting to give solidity to his views, he reserved the publication of his Memoir to a future time. The design of that paper (of which an abstract appeared in the account of the proceedings of the Royal Society of Edinburgh) is this: to show that all the formule of Fourier are quite accurate and applicable to physical phenomena. It will be observed that Fourier conceives the external and internal flow of heat to vary as the difference between two quantities, which he calls the tempera- tures. This hypothesis is not consistent then with nature; but it is not, therefore, altogether valueless; although the difference of tempe- rature does not determine the flow of heat, it does not follow that the difference of no other quantities does so. It is highly probable that the flow of heat is due to the difference between some two things. Now Dulong found that for external radiation, the flow of heat de- pends on the difference of two exponential functions of the tempera- ture. May it not, then, be the fact, that these exponentials, and not the temperature as measured by the air thermometer, are the elements by which nature proceeds ? Why should it be supposed that tempera- ture has any explicit connexion with the matter? Why, in fine, should we desire to retain our preconceived notions relative to internal trans- mission, when we find another law holds for external radiation? The author ventured on the hypothesis, then, that internal conduction fol- lows the same law as external radiation, viz. that the flow of heat is proportional, not to the difference of temperature, but to the difference of two exponentials of the temperature. To obviate the confusion that would be introduced into our language by such an hypothesis, he further ventured to suggest that the term “ thermature” should be adopted as the expression for this exponential function on which the flow of heat depends. This thermature would be the real measure of caloric— temperature of its effect on the thermometer. This quantity “ ther- mature” is nothing else than Fourier’s v. All that remains, then, in order to reduce the results of theory to those of experiment, is to sub- stitute for v, on which theory is made to depend, its value in terms of 6, the temperature as marked by experiment. It readily appears that o=—ALL— a *). The author has tested this result by all the expe- riments which he could find. But he regretted that a want of experi- ments rendered it impossible to decide the matter, thus leaving the theory of heat in a most precarious state, whilst its practical applications are become so vastly important. He hoped by his comments to excite some attention to the subject, especially among those who are labouring in the kindred field of the theory of light*. * Professor Kelland has undertaken, at the request of the General Commit- tee, to draw up a report on this subject, to be presented to the Association. TRANSACTIONS OF THE SECTIONS. 17 On the Temperature of the Earth in the deep Mines in the neighbour- hood of Manchester. By Eaton Hopcxtnson. Mr. Hodgkinson having some years ago received from Professor Phillips four thermometers belonging to the Association, was enabled, through the kindness of the proprietors of the following pits, and other parties connected with them, to institute experiments upon the temperature of the earth in each of them. The salt rock pit, 112 yards deep, belonging to the Marston Salt Company, near North- wich, Cheshire. The Haydock colliery, 201 yards deep, near to Warrington. The Broad Oak coal mine, 329 yards deep, near to Oldham. In the latter pit a thermometer placed in a hole three feet deep, bored in “metal,” and closed at the aperture, was examined weekly by Mr. Swain for twelve months, the temperature varying from 57° to 582° Fahr., it being lowest from the beginning of Fe- bruary to the middle of May, and highest in September and October to the middle of November. The experiments above mentioned were made in 1837 and 1838, and the results mentioned at the Birmingham meeting ; but the Broad Oak pit having been increased in depth since that time, a thermometer was inserted in it, ina hole bored in metal as before. It was in a place 408 yards deep, and indicated a temperature of 61°, remaining nearly constant for twelve months. Mr. Fitzgerald being recently engaged in sinking a deep coal pit at Pendleton, two miles from Manchester, Mr. Hodgkinson conceived this to be a favourable opportunity for getting additional information on the subject of sub- terranean temperature ; and, on his application to the proprietor, the engineer, Mr. Ray, readily made for him, during the sinking of the pit, and afterwards in the workings, the experiments of which the results are below. At 418 yards from the surface, the temperature, in a hole from three to four feet deep bored in dry rock, was 66°; at 4.50 yards deep it was 67°, and at 480 yards it was 69°. In the workings, at 461 and 471 yards deep, it was in both cases 65°. The mean temperature of the air at Manchester, according to Dr. Dalton’s experiments, is 48° Fahr.; and as the pits above-mentioned are not very far from Manchester, the mean temperature of the earth at the surface of each of them, may be considered as 48°. With that sup- position the distance sunk for each degree of Fahr. would be as below. In the Rock pit 32 yards. » Haydock coal pit 20 ~~, » Broad Oak do. a? Bote ae ant 39 bb) » Pendleton do. (shaft) 23-2 18 ” 93°7 23°2 ” = mean. 22'8 2? » Do. (in workings) piles re te The mean from the whole being 27 yards for each degree of tempe- rature. 1840. Cc 18 REPORT—1840. On the Principles of Electro-Magnetical Machines. By Prof. Jacos1, of St. Petersburgh. I have the honour to present to the British Association an historical sketch of the laws which regulate the action of electro-magnetic machines, laws which will enable us to determine in a precise manner the important question of the application of this remarkable force as a moving power. Since the commencement of my labours, which had partly a purely practical tendency, I proposed to myself to fill up as much as possible the blank which still remained in our knowledge of electro- magnetism. With the assistance of M. Lenz, I prosecuted the labours, which were the more arduous as they had but few precedents in the direction which I considered it necessary to follow, and we began to examine carefully the laws of electro-magnets. The report, which contains the results of our researches, was read in June 1838, before the Academy of Sciences at St. Petersburgh. I take the liberty of repeating here, very briefly, the contents of this first report. The problem which we sought to determine may be stated as follows: If a nucleus of malleable iron and a voltaic battery of a certain surface is given, into what number of elements should this surface be divided ? what should be the thickness of the wire of’ the helix which surrounds the nucleus ? and, lastly, what number of turns should this helix have, in order to produce the greatest amount of magnetism? I will not dilate here upon the manner in which we have proceeded, or upon the degree of certainty which belongs to the laws established according to our observations. I take the liberty of appending to this statement the report in question, and will proceed to explain the particular laws: Ist. The amount of magnetism engendered in malleable iron by galvanic currents is in proportion to the force of those currents. 2ndly. The thickness of the wire twisted into a helix, and surrounding a rod of iron, is absolutely of no consequence, provided that the helix have the same number of turns, and the current be of the same force. This law extends also to the case in which ribbons of copper were employed instead of wire. Nevertheless I must notice, that in order to obtain a current of equal force, it is necessary to employ a voltaic apparatus of greater force, if small wires which offer a greater resistance are employed. 3dly. If the current remain the same, the influence which the diameter of the helix exercises may be neglected in the majority of practical cases. 4thly. The total action of the electro-magnetic helix upon the rod of iron, is equal to the sum of the effects produced by each coil separately. Adopting these laws,and submitting them to calculation according to the formula of M. Ohm, the importance of which formula has but lately begun to be appreciated by some British philosophers, we have established the formula which contains all the particular con- ditions required to obtain the maximum amount of magnetism, which may be expressed in the following extremely simple manner, viz. the maximum of magnetism is always obtained when the total resistance of the conducting wire, which forms the helix, is equal to the total resistance of the pile. On referring to the remarkable law of the definite action Oe ae Sit ile aaa TRANSACTIONS OF THE SECTIONS. 19 of the galvanic current, established by Mr. Faraday, it is found that the magnetism of malleable iron divided by the consumption of zinc, —a quantity which we have called economic effect—is with reference to the maximum of this magnetism, a constant, or an expression into which neither the thickness of the wire nor the number of the elements into which the total given surface of the battery is divided, enters, but only the total thickness of the envelope. Having finished these first researches, and having obtained these results, which were highly satisfactory, not only for their simplicity, but also for their practical value, we set about extending our inquiries to iron rods of different dimensions. Is there, it may be asked, any specific effect produced by the length or thickness of the nucleus ? or does the degree of magnetism solely depend upon the construction of the helix, and the force of the current? The solution of this new pro- blem presents a greater difficulty than the problem which we had suc- ceeded in completely solving. Now, we are obliged to take iron rods of different dimensions, and consequently, in all probability of different qualities. Similar conditions with reference to the action of the electro- magnetic helices are likewise difficult to obtain ; and we soon perceived that these circumstances rendered it impossible to attain so close an accordance as that which we had obtained in our former observations. Although these experiments were made two years ago, the results have not yet been published, because, being occupied with other labours, we have not been able to find the necessary time fur their reduction and arrangement, and for the requisite calculations. Nevertheless I take the liberty of presenting to the Section some results, which are not devoid of interest, and which are intimately connected with the question of electro-magnetic machines. We submitted nine cylinders of malleable iron, each eight inches in length, and of different diameters, from three inches down to one-third of an inch, to the action of a voltaic current of the same force in each case, and we obtained the amount of magnetic force represented in the following table :— Diameter Magnetism Magnetism of the rods. observed. calculated. 3 447 4.42 QL 378 376 2 308 310 1} 246 244 1 175 178 $ 158 156 3 142 135 3 112 113 z 87 91 This calculation has been made according to the formula m = 131°75 d + 46°75, in which the constants have been obtained by the method of the least squares. The differences between calculation and observation are not so large that they cannot be attributed to the inevitable errors of observation, and to circumstances inherent in the c2 20 REPORT—1840. qualities of iron, &c. A similar agreement is found between other observations, which we shall describe in the report itself. I think, therefore, we may admit the following law, namely, that the amount of magnetism received by different iron rods of the same length, and sub- mitted to the influence of a current of the same force, is proportional to the diameter of the rods. I must remark, that the constant which we have added in the formula depends upon the magnetic influence which the helix exercises, independently of the nucleus of iron which it encloses. The practical consequences which may be de- duced from this remarkable law are of considerable importance. Among these, however, I will at present mention only the follow- ing. Having found that the amount of magnetism is proportional to the surface of the malleable iron, and taking into account the quan- tity of iron employed in the electro-magnets, it is ascertained that it is more advantageous to employ in the construction of electro-magnetic machines, rods of small instead of large dimensions ; or rather hollow iron, in accordance with my own experiments of 1837, which are found in ‘ Taylor's Scientific Memoirs,’ vol. ii. &e. I cannot pass over in si- lence the experiments of Prof. Barlow, who, as is well known, proved a long time before that the induction of the terrestrial magnetism upon malleable iron, depends only upon the surfaces, and is almost inde- pendent of the thickness. In order to ascertain the law of electro- magnets of different lengths, M. Lenz and I undertook numerous and laborious observations, which were extended even to rods of thirteen feet in length, and keeping in view at the same time the determination of the particular distribution of magnetism in the rods. Among these observations I shall only refer to such as seem most applicable to elec- tro-magnetic machines, and which have yielded results as simple as unexpected. The following table contains the results of some obser- vations made with rods of the same diameter, but of different lengths, covered with electro-magnetic helices, and influenced by a current of the same force. M being the magnetism of the extremities, and 2 the number of the coils of the helix, we have — = a, a formula according n to which we may calculate the numbers contained in the third column. The numbers in the fourth column are deduced from a series of other observations, made with the same helix of 960 turns, which did not cover the whole length of the rods, but were collected at the extre- mities only, where they occupied a space of about two inches in length. The helices being the same in all the observations, it was only neces- sary to divide the magnetism of the extremities by 960, in order to find the numbers of this column. a Oe TRANSACTIONS OF THE SECTIONS. 21 Table of Experiments upon the Magnetic Forces of Rods of different lengths. Mean value of one coil, | Mean value of one coil, Length of | Number | if the helix occupies | if the helix occupies the rods. | of coils. | the whole length. | only the extremities. Sy 946 7°334 7°560 Q"5 789 6°993 7°264 2 634 7°402 6°871 1°5 474 7°880 7°491 1 315 7°847 7°573 0°5 163 7°766 7°691 7537 7°408 From these numbers it will be seen that the influence of one coil of the helix is nearly the same for all the rods, and that their length does not exercise any specific influence. It is only in proportion to the number of the turns or revolutions, and to the force of the current, that the rods can acquire a greater or less amount of magnetism. The small rods even appear to have a slight advantage over large rods, since it has been found by experiments that the actual force of rods of three feet bears to that of rods of half a foot the ratio of seventy-three to seventy-seven. It is also found that there is a gain of seventy-five to seventy-four when the whole length of the rods is covered, instead of simply collecting the same number of coils around the extremities. The differences between the observations and the simple laws are, as will be judged, quite inconsiderable for practical purposes, and will, in time, I hope, entirely disappear by a complete integration embracing the whole length of the rods, and founded upon the effect of an ele- mentary part of the current. I will now hasten on to the immediate object of my present address. In March 1839, M. Lenz and I pre- sented to the Academy of Sciences at St. Petersburgh, a report, which I shall present to the Association. It contains the result of the expe- riments by which we have been enabled to establish the remarkable law, that the attraction of the electro-magnets is proportional to the square of the force of the galvanic current, to the infiuence of which the rods of tron are submitted. This law is of the highest practical importance, as it serves for the basis of the whole theory of electro-magnetic ma- chines. Before proceeding, I may be permitted to make some remarks concerning an instrument which I laid before the Academy of Sciences, in the commencement of this year. It is destined to regulate the gal- vanie current, and is of value in many investigations of this kind. During my sojourn in London, Prof. Wheatstone has shown me an in- strument, founded on exactly the same principles as mine, and with very inconsiderable modifications and differences. Now, it is quite impossible that he should have had the least notice of my instrument; but as it is probable that its use may be greatly extended, I must add, that while I have only used this instrument for regulating the force of the 22 REPORT—1840., currents, he has founded upon it a new method of measuring these currents, and of determining the different elements or constants, which enter into the analytical expressions, and on which depends the action of any galvanic combination. It is principally to the measure of the electromotive force, by those means, that Mr. Wheatstone has directed his attention; and he has shown me, in his unpublished papers, very valuable results which he has obtained by this method. While these purely theoretical researches were in progress, I did not fail myself to enter directly upon the question of the practical ap- plication of electro-magnetism. Unfortunately, I cannot here give the details either of the experiments which I have made upon a very large scale, or of the machines and apparatus of various kinds which I have constructed. The necessity of multiplying the facts or tangible results —a necessity the more urgent, because the practical applications of this force increased so very rapidly—this necessity, I say, has not al- lowed me time or leisure to digest and arrange them. I can only here express my readiness to afford any explanation of the details which may be desired. I will, however, particularly notice the satisfactory results of the experiments made last year with a boat of twenty-eight feet in length and seven and a half feet in width, drawing 2% feet of water, and carrying fourteen individuals, which was propelled upon the Neva at the rate of about three English miles in the hour. The machine, which occupied very little space, was set in motion by a bat- tery of sixty-four pairs of platina plates, each having thirty-six square inches of surface, and charged according to the plan of Mr. Grove, with nitric and diluted sulphuric acid. Although these results may perhaps not satisfy the exaggerated expectations of some persons, it is to be remembered, that in the first year, namely, in 1838, this boat being put in motion by the same machine, and employing 320 pairs of plates, each of thirty-six square inches, and charged with sulphate of copper, only half this velocity was obtained. This enormous battery occupied considerable space, and the manipulation and the management of it was very troublesome. The judicious changes made in the dis- tribution of the rods, in the construction of the commutator, and lastly, in the principles of the voltaic battery, have led to the successful result of the following year, 1839. We have gone thus on the Neva more than once, and during the whole day, partly with and partly against the stream, with a party of twelve or fourteen persons, and with a ve- locity not much less than that of the first invented steam-boat. I believe that more cannot be expected from a mechanical force, whose existence has only been known since 1834, when I made the first ex- periment at Koénigsberg, in Prussia, and only succeeded in lifting a weight of about twenty ounces, by even this electro-magnetic power. I must, on the present occasion, confess frankly and without reserve, that hitherto the construction of electro-magnetic machines has been regulated in a great measure by mere trials; that even the machines constructed according to the indisputable laws established with regard to the statical effects of electro-magnets, have been found ineficient, as soon as we came to deal with motion. Being always TRANSACTIONS OF THE SECTIONS. 23 accustomed to proceed in a legitimate manner, and feeling great regret at the irregular attempts which were being made everywhere, without any scientific foundation, this state of things appeared to me so un- satisfactory, that I could not but direct all my efforts to ascertain clearly the laws of these remarkable machines. I submit the formule relative to these laws, which appear to me to recommend themselves as much by their simplicity as by the natural manner in which they develope themselves. Let R represent all the mechanical resistances acting upon the machine, and v the uniform velocity with which it moves: we have for the power or mechanical effect, the expression T = R v. Let n be the number of the coils of the helix which covers the rods ; z, the number of the plates of the battery; B, the total resistance of the galvanic circuit ; E, the electromotive force; 2, a coefficient, which depends on the arrangement of the bars, the distance of the poles, and the quality of the iron; we have then for the maximum of the me- chanical effect which will be obtained, the expression— aw Z2 ER? igo Fe For the velocity, which corresponds to this maximum, B Tl. v= ~ Rn For the resistance acting upon the machine, n? 2? Ko 4B Lastly, for the ceconomic effect, 7. e. the duty or the mechanical effect divided by the consumption of zinc in a given time, E IV. O= rk These formule may be expressed in the terms :— lst, The maximum of mechanical effect which may be obtained from a machine, is proportional to the square of the number of voltaic elements, multiplied by the square of the electromotive force, and divided by the total resistance of the voltaic circuit. There enters, moreover, into the formula, a factor, which I have designated &, and which depends upon the quality of the iron, the form and disposition of the rods, and the distance between their extremities. The result is, that with reference to some other investigations, which I have made of voltaic combinations, and under similar conditions, the use of plati- num, zine, the resistance being the same, will produce an effect two or three times greater than the use of copper, zinc. 9nd, Neither the number of the coils of the helix which covers the rods, nor the diameter or the length of the rods themselves, has any influence upon the maximum of the power. It results, therefore, that neither by adding to the iength or diameter of the rods, nor by employ- ing a greater quantity of wire, can the power be increased. There is, Ts Ill. R = 24 REPORT—1840. however, this remarkable fact, that the number of coils disappears from the formula, simply because the force of the machine is ina direct ratio, and the velocity is in an inverse ratio, to the square of this number. It is thus that the number of coils, the dimensions of the rods, and the other constituent parts of an electro-magnetic machine, should be con- sidered simply as occupying the range of the ordinary mechanisms which serve for the transmission or transformation of the velocity, without increasing the available power. So it would be possible to use, instead of the ordinary wheelwork, rods of greater or less length, or a greater or less quantity of wire, in order to establish between the force and the velocity, the relation which the applications to manufacturing processes may require. 3rd, The mean attraction of the magnetic rods, or the pressure which the machine can exert, is proportional to the square of the current. This pressure is indicated by the galvanometer, which in this manner performs the function of the manometer of steam-engines. 4th, The economic effect, i. e. the duty or the available power, divided by the consumption of zine, is a constant quantity, which is ex- pressed most simply by the relation between the electromotive force and the factor k, which has been previously noticed. I may here repeat, what I stated elsewhere, that by employing platinum instead of copper, the theoretical expenses may be reduced in the proportion of nearly 23 to 14. 5th, The consumption of zinc, which takes place while the machine is at rest, and does not work at all, is double that which takes place while it is producing the maximum of power. I consider that there will not be much difficulty in determining with sufficient precision the duty of one pound of zine, by its transfor- - mation into the sulphate, in the same manner that in the steam-engine, the duty of one bushel of coal serves as a measure to estimate the effect of different combinations. The future use and application of electro- magnetic machines appears to me quite certain, especially as the mere trials and vague ideas which have hitherto prevailed in the construction of these machines, have now at length yielded to the precise and definite laws which are conformable to the general laws which nature is accus- tomed to observe with strictness, whenever the question of effects and their causes arises. In viewing on the one hand a chemical effect, and on the other a mechanical effect, the intermediate term scarcely presents itself at first. In the present case, it is magneto-electricity, the admi- rable discovery of Faraday, which we should consider as the regulating power, or, as it may be styled, the logic of electro-magnetic machines. On the Theory of Electricity. By C. J. Kennepy. The author shows in the commencement of his paper, that on the theory of a single fluid, the electrified aérial current proceeding from the positive wire must be superior in force to the electrified aérial eurrent proceeding from the negative wire. He describes various ex- TRANSACTIONS OF THE SECTIONS. 25 periments with light wheels, and suspended gold leaf, in which this appears to be a fact. He adverts to other experimenta crucis, all con- curring in his opinion to establish the theory of a single electric fluid, - as the movement of a line of water, or saline solution, from the positive or vitreous to the negative or resinous pole, as found by Mr. Porret and M. de la Rive; and appeals to ordinary experiments in which cards are perforated by electrical discharge in confirmation of the same view. The theory of a single electric fluid is capable of assuming two forms, in which material idio-repulsion is entirely discarded. The one form is that of an original theory adopted by Mr. Kennedy in the year 1825. It was deduced froma rather complicated fluxionary calculation, by which a beautifully simple result was obtained. An exponential fluxionary equation, involving all the possible powers and simple func- tions of the electric force, was employed. The result of the calculation was surprisingly simple, namely, that electrical action varies in the inverse ratio of the electric quantity ; or, A OC Pv Ices At represent the : i attraction of a material corpuscle for electricity, in any given electrical condition, suppose the neutral state, and g the quantity of electricity which that corpuscle then contains. The tendeucy of two material corpuscles ¢ ce’ towards each other, may be denoted by T, and is = 2 A'g =A'xq+tA!'xq. Now, if the electrical quantities of ¢ and ec! be- come each = 2, the attraction of each of these corpuscles for electricity ! I ! will become = ae and T’ will become = “-% x & + dg qg x @ as before ; that is, the joint tendency of the two corpuscles to mutual approach remains unaltered, so long as their electrical quantities are equal to each other, whatever each of these electrical quantities may be, whether a large quantity or a small. Suppose next, that the elec- trical quantity of ec becomes = 2, and that of c' = y, then their re- t Ag #4; and T will be spective attractions for electricity will be and t f ! ! yi xyt a a or Bray + Alga Now this must be greater ra 4g “ yi _ than 2 A’ gq, in every case in which z is unequal to y; for if x is un- ! ~ equal to y—because A! and q are constant quantities— A'@ ust be x ; F : unequal to re *. If abe greater than y, sie! must be greater than Z y ! ely, Now 44, Aa" FAB hen Whence,* 1 Y + “eu are oN than “ A' q; that is, the least possible value of Tis2 Al q3 -—in common language, the tendency of the two corpuscles to mutual * Kuclid’s Elements, Book v. prop. xxv. 26 REPORT—1840. approach, is the least possible when they contain equal quantities of electricity. It follows also, that the more unequal a and y are, the t f greater must the sum of A’gy and A’q= be; that is, the more the x electrical quantities of the two corpuscles differ, the greater is their tendency to mutual approach. The phenomena of electrical attraction, repulsion, and quiescence, may be explained on this theory, ina manner perfectly satisfactory, and exceedingly easy. The author then exemplified this in the following cases : 1. QUIESCENCE. Case 1—JLet A BC D be four small balls, equal to each other, homogeneous, equidistant in the same straight line, and all in the neutral electrical state. Case 2.—Let A be electrified plus, while C B D remain in the neutral state. Case 3.—Let A be electrified minus, while B remains in the neutral state. 2. ATTRACTION. Let A be positively, and B negatively, electrified. 3. REFULSION. Case 1.—Zet A and B be alike electrified plus. Case 2.—Let A and B be alike electrified minus. An Account of the Magnetic Observatory of Munich. By Dr, Lamont. The author stated that the building had been undertaken in April this year, and that the regular series of observations, comprehending both the daily observations from two to three hours, and the term-day observations, was commenced on the Ist of August. The Magnetic Observatory of Munich differs in two respects from other establishments of the same kind. In the first place, it is not a magnetical house, but a subterraneous building, which is situated to the S.W. of the Royal Observatory, and at a distance of about 120 feet, and connected with it by a subterraneous passage. The depth of the magnetic observatory below the surface of the earth is 13 feet, thus affording the advantage of a temperature nearly equal at all times of the year, and rendering the corrections applied to magnetic observations in order to reduce them to a fixed temperature—corrections which are in general subject to considerable uncertainty—if not unnecessary, at least sufficiently small to be determined with the utmost degree of accuracy. In the second place, the instruments are of greater dimensions than those ~ usually employed in magnetic observatories, and may be considered as sufficient in all respects for the most delicate investigations. The mag- netic bars weigh 25lbs. each ; the theodolite has a circle of 23 feet dia- TRANSACTIONS OF THE SECTIONS. 27 meter, and an achromatic telescope of 3} inches aperture. It may be remarked that the horizontal-force instrument differs from the bifilar magnetometer, the force that holds the bar in a direction perpendicular to the magnetic meridian being a spiral spring. Besides the instru- ments fixed in the observatory, there are portable instruments for making experiments with bars of 3lb., 1lb., 41bs., 10lbs. and 25lbs. The munificence with which the king of Bavaria has been always known to support the cause of science, and the liberality of the Crown Prince, who takes peculiar interest in physical researches, have contri- buted to render the magnetic observatory of Munich the most complete establishment of this kind on the continent. A general statement of the System of Meteorological Observations carried on in Bavaria. By Dr. LAMont. The Royal Observatory of Munich constitutes the central establish- ment, and has the superintendence of all meteorological observations made under public authority. There are meteorological observatories at Ratisbon, Augsburg, and Hohen-Peissenberg, the latter being si- tuated on the summit of a mountain 3000 feet above the level of the sea. Besides, meteorological observations are registered partly by members of the Royal Meteorological Society, partly by persons ap- pointed by Government, at 260 towns and villages in Bavaria. The observations thus obtained, though not equally complete, some of them being registered only once, some twice, and but a comparatively small number three times a day, will be found extremely valuable for the purposes of meteorology. Hourly observations of the barometer and thermometer have been made at the Royal Observatory of Munich since May 1838, by means of accurate registering instruments, constructed on a new principle. Dr. Lamont, in mentioning this extensive system of observations, referred for the results and further particulars to the annual publications of the Royal Observatory of Munich. He con- cluded by remarking, that the great object of meteorology was to find the causes from which the changes in the atmosphere arise ; to trace the propagation of these changes from one place to another, and the mo- difications they undergo on their way; and to show what relation exists between the states of the atmosphere at different parts of the globe, and how the changes at one place depend upon, or are connected with, simultaneous or preceding changes at another. This, he said, can only be attained by combining observations made in different coun- tries after a general and uniform system; and in mentioning at that meeting the extensive observations carried on in Bavaria, it was his intention to show how far a general system, such as had been just alluded to, was likely to be supported in that part of Germany, and to express the hope that such a general system will be introduced at no distant period, perhaps, by the same Association by whose exertions a similar system of magnetic observations has now so successfully been carried into effect. 28 REPORT—1840. Notice accompanying a Series of Meteorological Observations made at Trevandrum. By Mr. Cavvecort. The author commenced with observing, that having had an oppor- tunity in India of forwarding an inquiry which the British Association has considered to possess great interest, viz. that into the thermome- trical, barometrical, and hygrometrical condition of the atmosphere within the tropics, it was with feelings of great pride and pleasure that he was enabled, by his present visit to this country, to present to the meeting a series of hourly observations of the thermometer, baro- meter, and moistened bulb thermometer, carried on under his direc- tion and superintendence, at a situation only 83° north of the equator. The author then proceeded to describe the circumstances under which the observations were instituted in the following terms :—* In the beginning of the year 1837 it devolved on me to undertake the direction of an observatory then recently established at Trevandrum in the south of India, by His Highness the Rajah of Travancore, (a young native prince of that country, of whom, for his liberal patronage of science, his munificent encouragement of education among his sub- jects, and above all for his beneficent rule, it is impossible to speak too highly) and noticing among the recommendations promulgated by the British Association, that a set of hourly meteorological observations within the tropics was considered highly desirable, I thought the opportunity a good one for supplying this desideratum. I accordingly explained the matter to His Highness, and with the liberal confidence which I have always experienced from him, was immediately provided with the necessary means for accomplishing my purpose ; I have there- fore no other merit to claim (with respect to these observations) than that of a diligent perseverance in the task I had imposed on myself.” Mr. Caldecott then described minutely the building in which the observations were made, the instruments used, and the registers which accompany his communication; these observations have been made every hour since the commencement of June, 1837, are still in progress, and are intended to be extended to a period of five years from their commencement. The situation is described to be in latitude 8° 30! 35 north, longitude 55 8™ east of Greenwich, 170 feet above the level of the sea, and distant from it in a direct line about 2 miles. Every precaution was taken to ensure accuracy; and of the ob- servers (all natives of India), Mr. Caldecott remarks, that “after the first difficulty of instructing them is surmounted, their patient, diligent, and temperate habits peculiarly fit them for the office here required of them, and I have always found those who have been selected for the duty fully as trustworthy as, I imagine, is any class of persons to whom such observations are usually entrusted.” The registers are arranged in monthly tables, and contain, among other determinations, the following particulars clearly shown, and ready for any investigation to which they may be considered applicable ;_ viz. Ist, in “ Temperature.” 1. The mean of each hour for the month. TRANSACTIONS OF THE SECTIONS. 29 2. The mean of each day of the month. 3. The same two means for each period of ten days. 4. The mean range for the month, and for each ten days; the extreme range, &c. 2nd, in “ Pressure.” 1. The pressure of each hour for the month. 2. The mean pressure of each day of the month. 3. The same two means for each period of ten days, 4. The maximum and minimum pressure of each day, with the extreme va- riation for each day ; the maximum and minimum pressure of the month, with the extreme variation for the month, &c. 5. The four semi-oscillations for each 24 hours, with the mean values of them for the month. 3rd, in “ Humidity.” 1, The temperature of the air each hour (repeated from the register of tem- perature). 2. The depression of the wet-bulb thermometer for ditto. 3. The dew-point for each hour, calculated from Professor Apjohn’s formula, disregarding his correction for pressure. 4. The mean of all these for each day. 5. The quantity of rain for each twelve hours. Besides these monthly registers, the author exhibited two tables drawn - up in the form first adopted by Sir David Brewster, showing for the complete year of the observations, viz. from June 1837 to June 1838, Ist, The daily and monthly mean temperature. 2nd, The mean temperature of each hour for | from 8760 obser- each month, and for the whole twelve vations. months. Also two other tables, showing for the same period, Ist, The daily and monthly dew-points. 2nd, The mean dew-point of each hour for each month, and for the whole twelve ditto. months. The first two tables give for the mean temperature of the station 78°89, and the other two give for the mean dew-point 71°78. The barometric registers give by a mean of all the diurnal semi- oscillations for the same period the following results : Fall between 10 a.m. and 4.p.M. 0°109 inch. Rise 4. P.M. 10 p.m. 0°108 Fall 10 P.M. 4 a.m. 0:071 Rise 4am. l0aA.M. 0:073 Times of maxima between the hours of 9 and 10 morning and evening. Times of minima between those of 3 and 4 afternoon and morning. Mr. Caldecott concluded his communication by noticing that he was about to return to his post in India amply furnished with meteoro- logical, magnetical, and astronomical instruments, and added that, should the committee of the Physical Section of the British Association see fit to honour him with any suggestions as to points in meteorology, or any other branch of the physical sciences which his local situation 80 REPORT— 1840. and means might enable him to elucidate, or be of any use in, he would feel proud to receive its instructions, and would do all in his power to forward its objects. Note.—At the meeting of the General Committee on the 24th Sept., a com- mittee was appointed to consider the propriety of printing, in extenso, the hourly meteorological observations communicated by Mr. Caldecott, together with those made at Plymouth by Mr. Snow Harris, at the instance of the British Association. On Storms. By James P. Espy. Mr. Espy commenced by stating, that he had found, by examining simultaneous observations in the middle of storms, and all round their borders, that the wind blows inward on all sides of a storm towards its central parts, towards a point if the storm is round, and towards a line if the storm is oblong, extending through its longest diameter. He had been able to investigate within the last five years seventeen storms, without discovering one exception to the general rule. As an example of recent date, he described and illustrated by a map the course of the wind in Great Britain on the night of the 6th of January, 1839, between the hours of 10 and 12. The observations were thus stated : 1. Romney—strong at 8 p.m., S.E. 2. Thwaite—strong from 10 to 12, S.S.E. 3. Southwold—the Susannah driven on shore at 8 p.m., by a south-east wind. 4. Birmingham—wind strong, E. of south, till one in the morning. 5. Manchester—S.E. till 12 at night. 6. Leeds—ditto ditto. 7. Bridlington—got round S.E. in night, and continued so, blowing a gale till after midnight. 8. Whitby—at 103 p.m. S. by E., high wind. 9. Berwick—changed from E. of south to $.W., at 10 p.m. 10. Dundee—on the night of the 6th and day of the 7th, N.W. _ 11. Montrose—all night of 6th and 7th a hurricane, N.W. 12. Aberdeen—ditto ditto. 13. Cape Wrath—all 6th and 7th, N.W. 14. Scowrie—evening of 6th till 12 at night, N.W. 15. Isle of Glan—at 11 p.m., N.W. 16. Lismore—night of 6th, N.W. to N. 17. Corsewell—6 p.m. till 12, S.W. 18. Strangford, Ireland—at 12, night of 6th, S.W. 19. Mull of Galloway—south till 14 30™ a.m., of 7th. 20. Calf of Man—S.5.W. till midnight. 21. Liverpool—changed from §8.S.E. after 10. 22. Plymouth—S.W. till 12 at night of 6th. From this, and from documents which Mr. Espy proceeded to read, it appeared that during those hours the wind was blowing a violent gale on the north-western part of the island from the north-west, on the south-western parts from the south-west, and on the south-eastern parts a strong gale from the south-east and south-south-east ; and that TRANSACTIONS OF THE SECTIONS. 3Yr in the middle parts of the island it changed from south-easterly to south-westerly about those same hours—the change taking place about two hours sooner on the west side of the island than on the east side in the central parts, but much sooner in the northern parts than in the southern. ‘The barometer also fell sooner in the northern and western parts than in the southern and eastern. From these two circumstances he thinks it highly probable that this storm moved not exactly towards the east, but a little south of east, and if so, it would be similar to some storms which he had examined in the United States. The barometer was at its minimum at Cape Wrath, in the north-west corner of Scotland, two hours and a half sooner than at the Calf of Man, five hours sooner than at Edinburgh, and thirteen hours and a half sooner than at Thwaite, in Suffolk. Mr. Espy then stated that he had examined the data furnished by Col. Reid, of several hurricanes in the West Indies, and found conclusive evidence that the wind blew inwards to a central space in all these storms. Diagrams of two were exhibited: one on the 3rd of October, 1780, in which Savannah-la- Mar was destroyed. In that storm, at its very height, the wind at Savannah-la-Mar, on the south side of the island of Jamaica, was south,—and nearly opposite to that point, on the north side of the island, the wind was north-east, or nearly in an opposite direction, for two hours at the time of the greatest violence of the storm at both places. The other storm was on the 18th of August, 1837, off Char- leston, south-east. On that day, the ship Duke of Manchester had the centre of the storm passing over her, and, on the same day, the West Indian and the Rawlins, which were on the south-west of the Duke of Manchester, had the wind all day from 2 a.m. south-west, and at the same time the Cicero and the Yolof, on the north-east of the Duke of Manchester, had the wind north-east and east-north-east, the Yolof all day, till 8 p.m. Mr. Espy then stated that he had visited the tracks of eighteen tor- nadoes, and examined several of them with great care, and found that all the phenomena told one tale—-the inward motion of the air to the centre of the inverted cone of cloud as it passed along the surface of the earth. From all these facts he inferred that there is an inward motion of the air towards the centre of storms from all sides; and stated that this inference ought to be drawn from the well-known fact, that the barometer stands lower in the midst of a storm than it does all round its borders. Mr. Espy exhibited an instrument, which he called a Nephelescope, which enabled him to measure the expansion of air with great accuracy, and he found it to agree with calculations made on chemical principles. He then proceeded to give an outline of his theory, premising that the numbers he should introduce were not intended to be strictly accurate, and would be subject to many corrections,—one in particular, in which no notice had been taken of the specific heat of air under different pressures. The following are extracts. “When the air near the surface of the earth becomes more heated or more highly charged with aqueous vapour, which is only five-eighths §2 REPORT—1840. of the specific gravity of atmospheric air, its equilibrium is unstable, and up-moving columns or streams will be formed. As these columns rise, their upper parts will come under less pressure, and the air will therefore expand ; as it expands, it will grow colder about one degree and a quarter for every hundred yards of its ascent, as is demon- strated by experiments with the Nephelescope. The ascending columns will carry up with them the aqueous vapour which they contain, and, if they rise high enough, the cold produced by expansion from dimi- nished pressure will condense some of this vapour into cloud; for it is known that cloud is formed in the receiver of an air-pump when the air is suddenly withdrawn. The distance or height to which the air will have to ascend before it will become cold enough to begin to form cloud, is a variable quantity, depending on the number of degrees which the dew-point is below the temperature of the air; and this height may be known at any time by observing how many degrees a thin metallic tumbler of water must be cooled down below the tempe- rature of the air before the vapour begins to condense on the outside. The difference between the dew-point and the temperature of the air in degrees is called (by Mr. Espy) the complement of the dew-point*. “ As the temperature of the air sinks about one degree and a quarter for every hundred yards of ascent, and the dew-point sinks about a quarter of a degree, it follows that as soon as the column rises as many hundred yards as the complement of the dew-point contains degrees of Fahrenheit, cloud will begin to form; or, in other words, the bases of all clouds forming by the cold of diminished pressure from up- moving columns of air, will be about as many hundred yards high as the dew-point in degrees is below the temperature of the air at the time. If the temperature of the ascending column should be ten degrees above that of the air through which it passes, and should rise to the height of 4800 feet before it begins to form cloud, the whole column would then be 100 feet of air lighter than surrounding columns; and if the column should be very narrow, its velocity of upward motion would follow the laws. of spouting fluids, which would be eight times the square root of 100 feet a second, that is, 80 feet a second, and the barometer in the centre of the column at its base would fall about the ninth of an inch. As soon as cloud begins to form, the caloric of elasticity of the vapour or steam is given out into the air in contact with the little particles of water formed by the condensation of the vapour. This will prevent the air in its further progress upwards from cooling so fast as it did up to that point ; and, from experiments with the Nephelescope, it is found to cool only about one-half as much above the base of the cloud as below; that is, about five-eighths of a degree for one hundred yards of ascent, when the dew-point is about * The height of the bases of forming cumuli may be ascertained by the fol- t—t! lowing empirical formula: 103 (=) = height of base in 100 yards; tbeing the temperature of the air in degrees of Fahrenheit, and ¢! the temperature of the wet bulb seoung briskly in the air. each. dak ie TRANSACTIONS OF THE SECTIONS. 33 70°. If the dew-point is higher, it cools a little less, and if the dew- point is lower, it cools a little more, than five-eighths of a degree in ascending one hundred yards. «Now it has been ascertained by aéronauts and travellers on moun- tains, that the atmosphere itself is about one degree colder for every hundred yards in height above the surface of the sea; therefore, as the air in the cloud above its base is only five-eighths of a degree colder for every hundred yards in height, it follows, that when the cloud is of great perpendicular height above its base, its top must be much warmer than the atmosphere at that height, and consequently much lighter. Indeed, the specific gravity of a cloud of any height, com- pared to that of the surrounding air at the same elevation, may be calculated, when the dew-point is given; for its temperature is known by experiments with the Nephelescope, and the quantity of vapour condensed by the cold of diminished pressure at every point in its upward motion, and of course the quantity of caloric of elasticity given out by this condensation is known, and also the effect this caloric has in expanding the air receiving it, beyond the volume it would have if no caloric of elasticity was evolved in the condensation of the vapour. For example, according to the experiments of Prof. _ W.R. Johnson, of Philadelphia, a pound of steam, at the temperature of 212°, contains 1030° of caloric of elasticity ; and if the sum of the latent and sensible caloric of steam is the same at all temperatures, it follows, that a pound of steam being condensed in 1210 pounds of water at 32° would heat this water up one degree ; and, as the specific caloric of air is only 0-267, if a pound of vapour should be condensed in 1210 pounds of air, it would heat that air nearly 4°, or, which is the same thing, it would heat 100 pounds of air about 45°. And in all these cases it would expand the air about 8000 times the bulk of water generated; that is, 8000 cubic feet for every cubic foot of water formed out of the condensed vapour. And as it requires between 1300 and 1400 cubic feet of vapour, at the ordinary tem- peratures of the atmosphere, to make one cubic foot of water—if this quantity be subtracted from 8000 it will leave upwards of 6600 cubic feet of actual expansion of the air in the cloud for every cubic foot of water generated there by condensed vapour. “This great expansion of the air in the forming cloud will cause the air to spread outwards in all directions above, causing the barometer to rise on the outside of the cloud, above the mean, and to fall below the mean under the middle of the cloud as much as it is known to do in the midst of great storms. For example, if the dew-point should be very high, say 78°, then the quantity of vapour in the air would be about one-fiftieth of its whole weight; and if the up-moving column should rise high enough to condense one-half its vapour into cloud, it would heat the air containing it 45°, and the air so heated would occupy qi’s More space than it would be if it was not so heated. And if we assume a case within the bounds of nature, and suppose the cloud and the column under the cloud to occupy three-fourths of the whole weight of the atmosphere, or, in other words, if we suppose the top 1840. D 34 REPORT—1840. of the cloud to reach a height where the barometer would stand at 74 inches, and the mean temperature of the whole column 40° warmer than the surrounding air, then would the barometer fall under the cloud at the surface of the earth, ;4%, of 22°5, or a little more than 2 inches. “Though the air may be driven up by the ascending column much higher than the point assumed in the last article, the cloud will cease to form at greater heights, because the dew-point, at these great elevations, falls by a further ascent as rapidly as the temperature—and at greater elevations, it will even fall more rapidly. If, for instance, the air should rise from where the barometer stands at 6 inches to where it stands at 3 inches, the dew-point would fall about 20°, but the temperature would fall less than 20°, and therefore no vapour would be condensed by such ascent. “When a cloud begins to form from an ascending column of air, it will be seen to swell out at the top while its base continues on the same level, for the air has to rise to the same height before it becomes cold enough, by diminished pressure, to begin to condense its vapour into water; this will cause the base to be flat, even after the cloud has acquired great perpendicular height, and assumed the form of a sugarloaf. Other clouds also for many miles around, formed by other ascending columns, will assume similar appearances, and will moreover have their bases all on the same or nearly the same horizontal level ; and the height of these bases from the surface of the earth, will be the greatest about 3 o’clock, when the dew-point and temperature of the air are the greatest distance apart. The outspreading of the air in the upper parts of an ascending column will form an annulus all round the cloud, under which the barometer will stand above the mean; of course the air will descend in the annulus, and increase the velocity of the wind at the surface of the earth, towards the centre of the ascend- ing column, while all round on the outside of the annulus there will be a gentle wind outwards. Any general currents of air, which may exist at the time, will of course modify these motions, from the oblique forces they would occasion. The up-moving current of air must of course be entirely supplied by the air within the annulus, and that which descends in the annulus itself. The rapid disturbance of equilibrium, which is produced by one ascending column, will tend to form others in its neighbourhood ; for the air being pressed outwards from the annulus, or at least retarded on the windward side, will form other ascending columns, and these will form other annuli, and so the process will be continued. These ascending columns will have a tendency to approach, and finally unite; for the air between them must descend, and in descending the temperature of the whole column will increase, for it is known that the air, at great elevations, contains.more caloric to the pound than the air near the surface of the earth, because it is the upper regions that receive the caloric of elasticity, given out in the condensation of vapour into clouds. Therefore, when the air has descended some time in the middle, between two ascending columns, the barometer will fall a little, or at least not stand so high above the TRANSACTIONS OF THE SECTIONS. 35 mean as it does on the outside of the two clouds, and so the columns will be pressed towards each other. If one of two neighbouring columns should be greatly higher than the other, its annulus may overlap the smaller one, and of course the current under the smaller cloud will be inverted, and the cloud which may have been formed over the column thus forced to descend will soon disappear; for as it is forced downwards by the overlapping annulus of the more lofty column, it will come under great pressure, and its temperature will be thus increased ; and it is manifest, that as soon as its top descends as low as its base, it will have entirely disappeared ; and in the mean time the larger cloud will have greatly increased. “ As the air above the cloud formed by an ascending column is forced upwards, if it contains much aqueous vapour, a thin film of cloud will be formed in it by the cold of diminished pressure, entirely distinct from the great dense cumulus below; but as the cumulus rises faster than the air above it (for some of the air will roll off), the thin film and the top of the cumulus will come in contact; and sometimes a second film or cap may be formed in the same way, and perhaps a third and fourth. When these caps form, there will probably be rain, as their formation indicates a high degree of saturation in the upper air. “When the complement of the dew-point is very great (twenty degrees and more), clouds can scarcely form ; for up-moving columns will generally either come to an equilibrium with the surrounding air, or be dispersed before they rise twenty hundred yards, which they must do in this case before they form clouds. Sometimes, however, masses of air will rise high enough to form clouds; but they are generally detached from any up-moving column underneath, and of course cannot then form cumuli with flat bases ; such clouds will be seen to dissolve as soon as they form, and even while forming they will gene- rally appear ragged, thin, and irregular. Moreover, if the ground should be colder during the day than the air in contact with it, as sometimes happens after a continuance of very cold weather, then as the air touching the cold earth will be colder than the stratum above it, ascending columns cannot exist, and of course no cumuli can be formed on that day, even though the air may be saturated with vapour to such a degree as to condense a portion of it on cold bodies at the surface of the earth. Neither can clouds form of any great size, when there are cross currents of air sufficiently strong to break in two an ascending current, for the ascensional power of the up-moving current will thus be weakened and destroyed. This is one means contrived by nature to prevent up-moving columns from always increasing until rain would follow. Without some such contrivance it is probable that every up-moving column which should begin to form cloud when the dew-point is favourable, would produce rain; for as soon as cloud forms, the up-moving power is rapidly increased by the evolution of the caloric of elasticity.” _ Among the consequences of his theory, Mr. Espy describes in what manner it happens that rain does not fall on the leeward side of very D2 36 REPORT—1840. lofty mountains ; and under what circumstances appear what are called tornadoes on land and waterspouts at sea. “ On visiting the path of a tornado, the trees on the extreme borders will all be found prostrated with their tops inwards, either inwards and backwards, or inwards and forwards, or exactly transverse to the path. The trees in the centre of the path will be thrown either backwards or forwards, or parallel to the path; and invariably if one tree lies across another, the one which is thrown backwards is underneath. Those materials on the sides which are moved from their places and rolled along the ground, leaving a trace of their motion, will move in a curve convex behind; those which were on the left hand of the path will make a curve from left hand to right, and those on the left hand of the path will make a curve from right hand to left; and many of these materials will be found on the opposite side of the path from that on which they stood on the approach of the tornado. Also those bodies which are carried up will appear to whirl, unless they arise from the very centre—those that are taken up on the right of the centre will whirl in a spiral from left to right, and those on the left of the cen- tre will whirl in a spiral upwards from right to left. On examining the trees which stand near the borders of the path, it will be found that many of the limbs are twisted round the trees, and broken in sucha manner as to remain twisted, those on the right-hand side of the path from left to right, and those on the left-hand side of the path from right to left. However, it will be found that only those limbs which grew on the side of the tree most distant from the path of the tornado are broken; for these alone were subject to a transverse strain. The houses which stood near the middle of the path will be very liable to bave the roof blown up, and many of the walls will be prostrated, all outwards, by the explosive influence of the air within, and those houses covered with zine or tin, from being air-tight, will suffer most. The floors from the cellars will also frequently be thrown up, and the corks of empty bottles exploded. _ All round the tornado, at a short distance, probably not more than three or four hundred yards, there will be a dead calm, on account of the annulus formed by the rapid efflux of air above, from the centre of the up-moving and expanding column. In this annulus the air will be depressed, and all round on the outside of it, at the surface of the earth, there will be a gentle wind outwards, and of course all the air which feeds the tornado is supplied from within the annulus. Nor is this difficult to understand, when the depression of the air in the annulus is considered, for any amount may be thus sup- plied by a great depression. Light bodies, such as shingles, branches of trees, and drops of rain or water formed in the cloud, will be car- ried up to a great height, before they are permitted to fall to the earth ; for though they may frequently be thrown outwards above, and may then descend to a considerable distance at the side, they will meet with an in-blowing current below, which will force them back to the centre of the up-moving current, and so they will be carried aloft again. « The drops of rain, however, will frequently be carried high enough to freeze them, especially if they are thrown out above so far as to fall TRANSACTIONS OF THE SECTIONS. 37 into clear air, for this air will in some cases be thirty or forty degrees colder than the air in the cloud. In this case, if the up-moving column is perpendicular, the hail will be thrown out on both sides; and on examination it will be found that two veins of hail fall simultaneously, at no great distance apart. It is indeed probable, that in all violent thunder-storms in which hail falls, the up-moving current is so violent as to carry drops of rain to a great height, when they freeze and be- come hail. It is difficult, if not impossible, to conceive any other way in which hail can be formed in the summer, or in the torrid zone. In those countries in which an upper current of air prevails in a particular direction, the tornadoes and waterspouts will generally move in the same direction, because the up-moving column of air in this meteor rises far into this upper current, and of course its upper part will be pressed in this direction ; as the great tornado cloud moves on in the direction of the upper current, the air at the surface of the earth will be pressed up into it by the superior weight of the surrounding air. It is for this reason that the tornado in Pennsylvania generally moves towards the eastward. “ If a tornado should stop its motion for a few seconds, as it might do, on meeting with a mountain, it would be likely to pour down an im- mense flood of water or ice, in a very small space, for the drops which would be carried up by the ascending current would soon accumulate to such a degree as to force their way back, and this they could not do without collecting into one united stream of immense length and weight ; and of cuurse on reaching the side of the mountain, this stream, whether it consisted of water or hail, would cut down into the side of the mountain a deep hole, and make a gully all the way to the bottom of the mountain, from the place where it first struck. “‘ As the air spreads out more rapidly above than it runs in below, there will be a tendency in storms to increase in diameter, and this tendency will be greater on the north side than on any other, for the air in its efdux above finds less resistance on that side, for a reason assigned in the next paragraph; therefore it is probable that storms become elongated north and south, and then, if they move towards the east, they must travel side foremost. « At the equator, or at least those parts of it where the trade-winds are constant from east to west, it is probable tornadoes travel from east to west. For as the air in the torrid zone is about 80° in temperature at a mean, and the air in the frigid zone is about zero, the air in the torrid zone is constantly expanded by heat about 8% of its whole bulk in the frigid zone. This will cause the air at the equator to stand more than seven miles higher from the surface of the earth to the top of the atmosphere than at the north pole. The air therefore will roll off from the torrid zone both ways towards the poles, causing the barometer to fall in low latitudes, and rise above the mean in high latitudes. This will cause the air to run in below towards the equa- tor, and of course rise there. Now from the principle of the conser- vation of areas, it will fall more and more to the west as it rises, and of course the upper current of the air, at the equator; probably moves 38 ; REPORT—1840. towards the west. However, as the air rolls off above, towards the north, it will be constantly passing over portions of the earth’s surface, which have a less diurnal velocity than the part from which it set out; and as from the nature of inertia it still inclines to retain the diurnal velocity towards the east, which it originally possessed, when it reaches the latitude of about 20 or 25 degrees, it will then probably be moving nearly towards the north, and beyond that latitude its motion will be north-easterly. “Tf violent storm clouds, which necessarily rise to a great height into the upper current, are driven forward in the direction of the upper current, it is probable that the barometer will rise higher in that part of the annulus which is in front of the storm, than in the rear, and if so, a sudden rise of the barometer, in particular localities, may become, when properly understood, one of the first symptoms of an approach- ing storm. In consequence of the high barometer in front of the storm in a semiannulus, the air will be forced downwards there, and cause, in some cases, a more violent action of the air or wind backwards, meet- ing the approaching storm, than will be experienced in the rear of the storm. As the barometer will probably be highest in the centre of the semiannulus, north-east of the storm, in middle latitudes, the tendency of the wind to blow outwards on all sides from the centre may cause the wind in the beginning of the storm to blow so as to appear to whirl from left to right, on the east side of the storm, and from right to left on the west side. “As the air comes downwards in the semiannulus in front of the storm, it will come under greater pressure, and any clouds which it may contain will probably be dissolved by the heat of greater pressure, and therefore on the passage of the annulus it will probably be fair weather. Also, as the air above always contains more caloric to the pound than the air below, there will be an increase of temperature on the passage of the annulus, partly from the increased pressure, but chiefly by the descent of the air. In very hot climates, this increase of temperature in front of the storm will be very sensibly felt. The in- creased pressure in the annulus round a volcano, when it suddenly bursts out, will sometimes, under favourable circumstances, be very great, and of course the air will be depressed from a great height ; so that some portion of the very air which has gone up in the central parts of the ascending column, and formed cloud by the cold of di- minished pressure, will be forced down to the surface of the earth, bringing with it the caloric of elasticity which it received from the condensing vapour; if so, the heat experienced at the time of this descent will be very great. “These hot blasts of air will alternate with cold blasts; for the air which is forced down from great heights in the annulus will not only be very hot, but very dry, having condensed its vapour in its previous ascent. Now, when this hot dry air flows inwards again towards the voleano, and ascends, it will not form cloud, because of its want of vapour, and therefore the process of cloud-forming will cease, and con- sequently hail and rain will cease too, until more air from a greater ’ TRANSACTIONS OF THE SECTIONS. 39 distance, that has not been deprived of its vapour, flows in and ascends. Then cloud will again begin to form, and the violence and rapidity of the outflowing of the air above will be increased by the evolution of the caloric of elasticity—the barometer will rise rapidly in the annulus, and fall in the central part of the ascending column; and these alterna- tions may continue while the volcano is in activity, more particularly if the violence of the volcano itself should be increased periodically. “ As air cannot move upwards without coming under diminished press- ure, and as it must thus expand and grow cooler, and consequently form cloud, any cause which produces an up-moving column of air, whether that cause be natural or artificial, will produce rain, when the complement of the dew-point is small, and the air calm below and above, and the upper part of the atmosphere of its ordinary temperature, “ Volcanoes, therefore, under favourable circumstances, will produce rain; sea-breezes, which blow inwards every day towards the centre of islands, especially if these islands have in them high mountains, which will prevent any upper current of air from bending the up- moving current of air out of the perpendicular, before it rises high enough to form cloud, such as Jamaica, will produce rain every day; great cities where very much fuel is burnt, in countries where the com- plement of the dew-point is small, such as Manchester and Liverpool, will frequently produce rain; even battles, and accidental fires, if they occur under favourable circumstances, may sometimes be followed by rain. Let all these favourable circumstances be watched for in time of drought (and they can only occur then), and let the experiment be tried; if it should be successful, the result would be highly beneficial to mankind. It might probably prevent the occurrence of those de- structive tornadoes which produce such devastation in the United States ; for if rain should be produced at regular intervals, of no great duration, the steam power in the air might thus be prevented from rising high enough to produce any storm of destructive character.” Independently of its utility in this manner, Mr. Espy pointed out in what way a knowledge of this theory would be highly useful to the mariner, to enable him to direct his vessel so, when one of these great storms comes near him, as to use as much wind in the borders of the storm as will suit the purposes of navigation; to know in what direc- tion a great storm is raging when it is yet several hundred miles from him; and if the storm should be of such great length, moving side foremost, as to preclude the possibility of avoiding it, to know in what direction to steer his ship, so as to get out of the storm as soon as pos- sible. The sailor also will be able to know when he is out of danger, and by observing storm clouds on their approach to ascertain the di- rection in which storms move. On this important subject the author added other remarks and illustrations, which would lose their value by the abridgement rendered necessary by the rules of the Association. 40 REPORT—1840. Extract of a letter from Mr. Redfield to Sir J. F. W. Herschel. New York, July 28, 1840. S1r,—The interest which you have manifested in the progress of meteorolo- gical science encourages me to commit to your care the accompanying plans and memoranda relating to American storms and tornadoes. The map which illustrates the direction of wind in the great storm of De- cember 15, 1839, at noon, with its accompanying schedule of observations, I beg you to offer to the British Association at the September Meeting in Glas- gow—unless you should deem it inappropriate, or consider some other disposi- tion of the same as more desirable—which I submit to your better judgement. The sketch of the various directions of prostration found in a section of the track of the New Jersey tornado of June 19, 1835, with its schedule of obser- vations, was designed to furnish you with some of the evidences of rotation found in the track of the tornado. Some distinguishing facts, which are thus presented, I deem to have been overlooked by others, or at least misappre- hended in their bearing. But, although this single sketch of tornado action was thus mainly intended for your private use, yet, on penning some remarks to accompany it, I was reminded of the claims which Professor Bache had upon me, growing out of my published remarks on the discussion at New- castle in 1838; and as the subject is not unlikely to engage attention at the ensuing meeting in Glasgow, I have thrown into short compass some of the considerations which appear to me to establish the whirling action. From these, and various other observations in my possession, I trust to be able successfully to meet (if necessary) any objections which have been, or may be started against the whirlwind theory, as applicable to gales and tor- nadoes. But for this, it is necessary that the objections should be made ina printed and responsible form, in order that the true state of the case may not be mistaken or evaded. As regards the map and schedule of observations for the December storm, perhaps I should not have taken the trouble to prepare them, had it not been intimated to the public in reference to my former account of this storm, as it appeared at sunset, that had the observations been given for the middle of the day, the wind arrows at Nantucket, at Cape Cod, and at New Bedford, and with the ship Morrison, would all have pointed in towards a central line. It has long been my intention to prepare and publish a more full examina- tion of the phenomena of the New Jersey tornado and other destructive whirl- winds, but my avocations and habits are not the most favourable to the execu- tion of this design. I beg you to make such disposition of the paper now sent as you may deem most desirable and proper. I am, with great respect, Your most obedient servant, W. C. REDFIELD. The documents to which this letter refers were not received in time to be laid before the meeting. ——__—. On the Dew-Point. By Dr. ANDERSON. The author explained the principles of the formula, which he de- duced several years ago from the experiments of Dalton and Gay- Lussac, for determining the various objects connected with the hygro- metric state of the air; and showed, by means of tables which he had constructed from it, the facility and despatch with which the absolute TRANSACTIONS OF THE SECTIONS. 4l as well as the relative humidity of the atmosphere, together with the dew-point, might be obtained. He concluded his observations on the subject by pointing out the exact coincidence which holds between the dew-point and the minimum nocturnal temperature; and proved that the quantity of moisture in the state of vapour, which exists in the air in every region of the earth, operates as a check upon the diminution of temperature by radiation during the night; for this obvious reason, that the transition of the aqueous vapour to the liquid state evolving its latent caloric, warms the cireumambient air, and by giving birth, at the same time, to clouds in the form of vesicular vapour, counteracts the cooling processes to which the nocturnal air is exposed in the ab- sence of the sun. This fact, so important in meteorology, affords an illustration of the reason why the windward sides of continents and large islands are warmer than their leeward sides, in the same parallel of latitude; and why dry and parched tracts of land are always found liable to severe cold during the night. It also furnishes an explanation of the causes which occasion the deflections of the isothermal lines, when taken in connexion with the modifications which these lines re- ceive from geographical position and elevation above the earth’s surface, On a Method of Prognosticating the probable mean Temperature of the several Winter Months from that of corresponding Months in the preceding Summer. By Grauam Hurcuinsoy, Esq. From the slowness with which the increased temperature of summer penetrates the surface of the ground, it occurred to the author, that the last portion absorbed during the summer half of the year, and which descends to the least depth below the surface, should be the first portion given off during the winter half; and in like manner, that the first portion absorbed during the summer half, and which must descend to a greater depth below the surface than any other portion, should be the last to be given off during the winter half; and agreeably to the principle above stated, the months in which an absorption of heat takes place, should have corresponding months of retrocession, or some approximation thereto; and consequently that the mean atmospheric temperature of any month in the summer half of the year, would afford a means of prognosticating the mean temperature of its corresponding ’ month in the winter half, so far at least as that mean atmospheric tem- perature depended upon the retrocession of heat absorbed during the “previous summer half. The corresponding months of temperature assumed by the author, are as follows :— August has October following yaly me ee for its corresponding month May A January of temperature. April .. February If, then, August be warmer than its average, the mean atmospheric 42 REPORT—1840. temperature of October following should likewise be warmer than its average: on the contrary, if August be colder than average, October following should likewise be colder than average. The same method applies to the other months. If there were no other cause for variations in the mean tempe- rature of the winter months in different years, except differences in the amount of solar heat absorbed during the months of cor- responding temperature in the previous summer half of the year, the mean temperature of each winter month would always bear a strict relation to that of its corresponding previous summer month ; and, consequently, if the one were known, the other could with certainty be predicted. But there are other causes which diversify the mean tem- perature of the same months in different years; and these being inde- pendent of the one under consideration, may either be co-operating with it, or acting in opposition to it. For instance, the proportion of north- erly and southerly winds, and the amount of rain that falls during the same winter months of different years, varies greatly. Whether, there- fore, among so many other distinct causes of diversity of temperature, the difference in the amount of solar heat absorbed during the summer months does sensibly affect by its retrocession the mean atmospheric temperature of the corresponding months of temperature during the subsequent winter season, so as to afford any probable means of pro- gnostication, can only be determined by reference to statistical tables of the mean temperature of the different months in a succession of years. From tables then referred to, Mr. Hutchinson said, it appeared that in Scotland deviations in the mean temperature of the summer months have a visible influence in producing like deviations in their corresponding months of temperature in the subsequent winter half of the year. It appeared also, that in the generality of years, the other disturbing causes which diversify the temperature of the same winter months in different years, such as variations in the direction and force of the winds, &c. have less influence, when averaged for a month, than we would be apt, @ priori, to suppose. And when the same months, for a number of years, are grouped together, and compared as is done in the tables, the disturbing causes, which may occasion a great deviation from the mean temperature in any particular month in one year, seem partially to neutralize each other, and render the influence of unusual warmth or unusual coldness, in any summer month, in pro- ducing a similar degree of unusual warmth or coldness in its corre- sponding winter month, more apparent than could have been anti- cipated. The author concludes by some observations as to the most suitable hour of registering temperature for the purpose of testing and applying his speculations (preferring 11 a.m.), and notices as an inference from the simple consideration of the ratio of solar radiation in summer and winter, that the dependence of winter temperature on summer heat, according to the plan of examining it already exemplified, should be greater and more obvious the higher the latitude of the place of obser- vation. TRANSACTIONS OF THE SECTIONS. 43 On Excessive Falls of Rain. By Professor Forses. ‘It appears, from the report of the Birmingham Meeting of the British Association, as given in the Atheneum (No. 618), that doubt has been thrown on the statement of the remarkable fall of rain cited in my former report. I was not present at either of the dis- cussions alluded to; I therefore take this opportunity of stating the authority upon which these very surprising falls of rain were ad- mitted into my report,—authority so ample, that, as an historian of science, I could not have omitted them, improbable as they do most certainly appear. The fall of thirty inches of rain within twenty-four hours, took place at Genoa [not Geneva, as printed in the report] on the 25th of October, 1822. An assertion to this eftect having appear- ed in a Genoese newspaper, the editors of the Bibliotheque Universelle wrote immediately to make the necessary inquiries as to an observation so unprecedented. ‘The reply which they obtained from M. Pagano, ‘ observateur exact*,’ is given at length in their journal, and is not, I think, the less satisfactory, because this result was obtained by the most inartificial of rain-gauges. ‘ Deux sceaux de bois presque cylindriques, dont l'un de vingt-quatre et l’autre de vingt- six pouces de hauteur, qui m’avoient servi pour quelques expéri- ences sur la vendange, étoient restés vides dans mon jardin. La pluie de Vendredi 25 Octobre n’avoient pas encore cessé de tomber que déja ils en étoient remplis.. He then proceeds to state on what grounds he infers that four inches more of rain fell after the larger vessel had been filled, making a total of thirty inches French (thirty-two English); and adds a statement of several facts, to show that the effects of the deluge in the neighbourhood bore a proportion to the magnitude of the cause. M. Arago, quoting the result, adds: ‘Ce résultat inoui inspira des doutes 4 tous les météorologistes, on soupconnait une erreur d’impression; mais M. Pagano, observateur exact, a écrit aux rédacteurs de la Bubliothéque Universelle une lettre qui met le fait hors de toute contestation}. Fortunately, however, this local deluge (for it appears, by the letter of M. Pagano, to have extended but a very short distance,) is nearly rivalled by a similar fact recorded in the south of France by an experienced observer, who seems to have been in the practice of measuring the fall of rain for twenty-three years at least, M. Tardy de la Brossy, of Joyeuse, Dép. de YArdéche. M. Arago, who records the observation, and gives it the weight of his authority, does so in these words: ‘ Le 9 Octobre 1827, _ dans lintervalle de vingt-deux heures, il est tombé, dans la méme ville de Joyeuse 29 pouces 3 lignes d’eau (vingt-neuf pouces trois lignes). J’écris le résultat en toutes lettres, afin qu’on ne croie pas 4 une faute d'impression{.’ When I add, that these two results, surprising, and perhaps unexampled as they are in the history of science, have, on * Vol. xxii. partie Physique, p. 67. + Ann. de Chim. et de Phys. xxvii. 407. t Ann. de Chim. et de Phys. xxxvi. 414. 44 REPORT—1840. account of the testimony by which they are established, been received not only in France and Switzerland, but in Germany and England, J conceive that they are undoubtedly entitled to stand part of the history of meteorology. I proceed to add a notice of a few other remarkable falls of rain, though there is nothing on record comparable to the two preceding ones. Flaugergues, the eminent meteorologist of Viviers, obtained, on the 6th of September, 1801, 13 inches 2:3 lines (143 English inches) of rain in eighteen hours. On the 20th of May, 18927, there fell at Geneva 6 inches of rain in three hours. At Perth, on the 3rd of August, 1829, there fell 4-5ths of an inch in half an hour. On the 22nd of November, 1826, I observed at Naples a fall of 9-10ths of an inch of rain and hail in thirty-seven minutes. Were the equatorial records of the fall of rain as minute in respect of distribution as of total amount, we should doubtless have records of enormous falls within twenty-four hours; none so recorded, that I am aware of, approaches the results at Genoa and Joyeuse. From the total quantities measured, it is evident that the result for particular days must be enormous. Don Antonio Lago observed at San Luis, Maranham (3° S. latitude), a fall of 23 feet 4 inches 9:7 lines in a year. Roussin states (his account is confirmed) that at Cayenne (5° N. lat.), in February, 1820, there fell, in ten hours, 1°25 inch of rain; and between the Ist and 24th of February, twelve feet 7 inches. From observations in the Ghauts, it appears that, in the eastern hemisphere, in lat. 18° N., 302:21 inches of rain have been measured ; a quantity exceeding that stated on the authority of Roussin, and which was once considered almost incredible ; and of this quantity (25:2 English feet), nearly 10 feet fell in the month of July alone.” Col. Sykes communicated the contents of a letter from India, from Capt. Aston, one of the diplomatic agents of the government of Bom- bay, in Kattywar, on the subject of a recent singular shower of grain. He stated that full sixty or seventy years ago, a fall of fish, during a storm in the Madras Presidency, had occurred. The fact is recorded by Major Harriot, in his “ Struggles through Life,” as having taken place while the troops were on the line of march, and some of the fish falling upon the hats of the European troops, they were collected and made into a curry for the general. This fact for probably fifty years was looked upon as a traveller’s tale, but within the last ten years so many other instances have been witnessed and publicly attested, that the singular anomaly is no longer doubted. The matter to which he had to call the attention of the Section was not to a fall of fish, but to an equally remarkable circumstance, a shower of grain. This took place on the 24th of March, 1840, at Rajket, in Kattywar, during one of those thunder storms, to which that month is subject; and it was found that the grain had not only fallen upon the town, but upon a consider- able extent of country and round the town. Captain Aston collected a quantity of the seed and transmitted it to Col. Sykes. The natives TRANSACTIONS OF THE SECTIONS. 45 flocked to Capt. Aston, to ask for his opinion of this phenomenon; for not only did the heavens raining grain upon them excite terror, but the omen was aggravated by the fact that the seed was not one of the cultivated grains of the country, but was entirely unknown to them. The genus and species was not immediately recognizable by some botanists, to whom it was shown, but it was thought to be either a spartium or a vicia. A similar force to that which elevates fish into the air, no doubt operated on this occasion; and this new fact corrobo- rates the phenomena, the effects of which had been previously wit- nessed. New Experimental Researches on Rain. By Joun Puiu.irs, F.R.S. The author proposed, by a new train of researches on the quantities of rain received on horizontal surfaces at different heights above the ground, by a contemporaneous series of experiments on the direction and angle of inclination of the descending lines of rain drops, and by contemporaneous registration of wind, temperature and moisture, to furnish additional data of importance in the theory of rain. Referring to the results obtained in his former discussion of three years’ observa- tions on the quantities of rain on York Minster (212 ft. above ground), the Yorkshire Museum (42 ft.), and on the ground, made by Professor Phillips and Mr. William Gray, the author noticed the statements of Prof. Bache, Dr. Daubeny, and others, as to the inequality of the re- ceipt of rain about the angles of a building and at small heights above it, in consequence of local aerial deflexions; and though in these re- spects the experimental results obtained in the three years’ York series appeared liable to small objection, many reasons of importance decided that in this new course of experiments, destined to last many years and to include a variety of contemporaneous records, the rain gauges should be placed in an open ground. It was further determined to place them at heights above the ground, corresponding to the depths below the surface to which the thermometers of Arago, Quetelet and Forbes, are sunk; i. e. to 0, 3, 6, 12, and 24 French feet. At present there are placed in the author's garden-ground four gauges at heights of 0, 3, 6, 12 French feet. The method of observation is of a peculiarly easy de- scription, so that in the midst of rain the momentary rapidity of the fall of rain can be perfectly ascertained in all the gauges. For example, in a very heavy shower, the maximum rapidity of rain accumulation, was 0:010 inch in two minutes of time = 0°300 inch in an hour. The gauges are, in common language, of the same size; but the author, not trusting to this supposed equality, makes the four gauges pass through a circle of positions, so that at the end of a year about 12 changes of position will have occurred, and the error of size in any one or more of the gauges be equally distributed over the various positions, and the registration be finally correct, without any applied calculation. The results, from June 1 to September 3 inclusive, in which period the changes of the gauges have not been sufficient to equalize their errors, are— 46 REPORT—1840. 12 feet above ground...... ican sereesnena +. 8206 6 feet above ZrOUNA.........seeeseeeeeerers 8249 3 feet above Ground......s.eseesseaseeeeees 8314 O feet above ground.........++sss.e+ seeeee 8408 During this period it has sometimes happened that more rain fell in the upper gauges, a circumstance apparently dependent on the dryness of the air, which has been very remarkable in the early part of the period in question. 1. 2. 3. 4. June 30 1575 1547 1509 1508 July 12 2018 2030 2046 2022 Aug. 14 2347 2315 2300 2260 Sept. 3 2468 2422 2394 2416 8408 8314 8249 8206 maximum rate 0100 in 2’ = 300 in one hour. In the second part of his communication the author describes a new construction of rain gauge for the purpose of determining the direction in which rain comes, and the angle of inclination at which it descends. For this purpose a compound gauge is constructed, having five equal receiving funnels and tubes; one with a vertical tube and horizontal aperture, the other four with tubes recurved so as to present the open- ings of the funnels in four vertical planes directed to four quarters of the horizon (see diagram), where / is the horizontal funnel, v', v", v'’, three of the four vertical openings, and ec’ ec" cl’, three corresponding cocks for letting off the water into a graduated tube. The rain which falls in the funnels A, v! vv!" v'" being carefully measured after each shower, the observer is able immediately to deter- mine the direction and inclination of the rain in each of the following cases :— 1. If the rain has fallen in a direction exactly coinciding with any one of the vertical funnels, that and the horizontal funnel alone receive any TRANSACTIONS OF THE SECTIONS. 47 rain. The direction thus known by observation, the angle of inclina- tion of the descending rain from the vertical is easily calculated. 2. If the rain has fallen (in quantities g and g') in two of the verti- eal gauges as well as in h (in quantity H), then the direction of the rain, intermediate to the positions of the two receiving vertical gauges, may be easily calculated (by considering g and q! as sine and cosine ; the ratio between them being = cotangent of the angle by which the rain direction deviates from that of the gauge which receives most rain). This known, the quantity (Q) which would have been received, in a vertical funnel directly opposed to the rain, is also calculable, being =V@P+q"; and, finally, the angle of inclination from the vertical, H at which the rain descends, is calculable, its cotangent being = ai Observations with this instrument have been made satisfactorily for some months, and the author has found the angle of inclination of de- scending rain to vary from 0 to 6°, 13°, 17°, and in one case to 35°, without perceiving that these very unequal inclinations had any sensible effect on the relation of the quantities of rain received in the gauges which are placed at different elevations, On the Formation of Rain. By G. A. Rowertt. The author states his hypothesis, that vapour on rising carries with it its proportion of electricity according to its expanded surface, and on being condensed, becomes, if insulated, surcharged with electricity ; this buoys up the vapour by its lightness, and prevents ‘the for- mation of rain by its repulsive power, and, on its escape, the par- ticles of vapour attract each other and form rain. He then explains the phenomenon of rain, as follows :—That hills and mountains being more subject to rain than plains, is owing to their attracting the elec- tricity from the clouds or invisible vapour; that the rain accompany- are piled to a great height, and that any violent commotion in such _acloud would cause such heavy rains as follow flashes of lightning ; _that the successive Slashes of lightning JSrom the same cloud may be from vapour becoming more and more condensed, thus causing suc- €essive accumulations of electricity on the surface of the vapour, or Mulations; that the change in weight of the atmosphere previous to and during rain, is caused by the electricity passing from the cloud or invisible vapour to the earth, displacing the heavier air, and thus causing 48 REPORT—1840. the atmosphere to be lighter; that the greater quantity of rain falling on the earth than at any elevation in the same locality, is occasioned by each falling drop of rain attracting to itself every particle of invi- sible vapour which may be floating within the sphere of its electrical attraction, and thus increasing its bulk. The paper concludes with proposing the experiment of raising elec- trical conductors to the regions of the clouds by means of balloons; which, in the author's opinion, would withdraw the electricity, and cause clouds and rain to be formed. On the Cause of the Aurora, §c. By G A. Rowe tt. The phenomenon of the aurora is explained thus :—The vapour rising at the equator, being greatly expanded, ascends to a great height with a great accumulation of electricity ; is thence carried by the cur- rents of air towards the poles, where the electricity again escapes to the earth and rushes along its surface, and the vapour in the lower parts of the atmosphere towards the equator is again carried off, thus cau- sing currents of electricity ; this circulation continues freely while the air at the poles is damp; but during the severe frosts of winter in the frigid regions, the air, near the earth’s surface, is nearly or quite dry, and the aurora is exhibited by the electricity passing through this non-conducting medium. By these currents, and the supposition that magnetism is owing to the attraction which the magnet has for electricity, which from some peculiarity can pass through it in one direction only, and that there be two sorts of electricity, one predominating in each hemisphere, the va- rious phenomena of magnetism are explained thus:—The direction of the needle is owing to its being attracted in the direction from which the streams passing through it are derived, the streams in this hemi- sphere converging to the north pole, and diverging or escaping from the south pole to gain their equilibrium ; that the dip is caused by the currents derived from the earth being stronger than those from the air and vapour above the needle; that the variation is owing to the greater quantity of electricity received by the earth at the magnetic poles, diverging east and west to gain its equilibrium in passing towards the equator; that the probable cause of the great quantity being re- ceived at these parts of the earth, is from the height of land conduct- ing the electricity to the earth, or because the temperature is constantly lowest at these points of the earth, thus causing a draught of air, vapour, and electricity, from the warmer parts of the earth through the upper parts of the atmosphere ; and that the daily variation is occasioned by — the greater or lesser formation of vapour, according to the direct action of the sun on different parts of the earth. The repulsion of similar and attraction of opposite poles of the magnet is thus explained :—The needle is kept in its magnetic meridian ¥ t by the converging streams to the north pole: now if the north pole of ae a TRANSACTIONS OF THE SECTIONS. 49 a magnet be brought near the north pole of the needle, the streams on that side are intercepted by the magnet, while the streams on the op- posite side attract the needle with the appearance of its being repelled by the magnet; or, if the south poles be brought near, they appear to repel, by the diverging streams being attracted in opposite directions to gain their equilibrium ; but the opposite poles attract each other by the streams from the south pole of the one being attracted by the north pole of the other magnet. The probability that magnetism is owing to the passing of some fluid through the magnet, is shown by the fracture of the magnet or by magnetizing a ring, which shows no signs of magnetism until pales and which again disappears on the broken parts. being brought into contact, which is explained by supposing the fluid to circulate within the ring, and therefore no magnetism can be exhibited till the line of continuity be broken. The author supports his opinion by general reference to the obser- vations on the aurora, &c., in the Appendix to Captain Franklin’s Journey to the Polar Seas, and concludes with proposing the experi- ments of raising electrical conductors to the height of the clouds in the frigid regions during the frosts in winter, which in his opinion would cause the aurora to be exhibited, and lead to important discove- ries in the science of magnetism. Observations on the Tides in the Harbour of Glasgow, and the Velocity of the Tidal Wave in the Estuary of the River Clyde, between Gilas- gow and Port Glasgow. By Wit.1Am Ba tp, F.R.S.E., MRLA., &e. The first series of observations made on the tides was commenced the 26th of April, 1839, and extended to the 1st of October, 1839 ; it ‘has been tabulated, and contains 158 observations of the rise and fall of the tides. It is necessary to observe that during the first portion of the time these tide observations were only made during the day, and did not extend to the night tides. These 158 observations assign a mean rise and fall of tide in the harbour of Glasgow of 6 feet 7:20 inches. The number of tide observations made from the 1st of October, 1839, to the 27th of August, amounts to more than 1200. These are tabulated and divided into months, but such of the tides as have been much dis- turbed by floods have been rejected. The mean rise and fall of these 1213 tides, assigns an average of 6 feet 8°98 inches. Mr. Bald presented tables in which were contained the principal results arrived at, by comparing the periods of new moons, first quarter, full moon, and last quarter, and diagrams representing the observations in a continuous line. He has also drawn out eight sections, showing the perpendicular rise and fall of the tide for every fifteen minutes in the harbour of Glasgow, at Clyde Bank, ‘alias Bay, and Port Glasgow. 1840. 50 REPORT—1840. He has also measured the velocity of the ebbing and flowing of the tidal current in various parts of the River Clyde, from Glasgow Har- bour to Port Glasgow. It appears from these observations that the tidal wave runs from Port Glasgow to Bowling at a rate or velocity of 14°56 miles per hour; from Bowling Bay to Clyde Bank at a rate of only 6°82 miles per hour; but from Clyde Bank to Glasgow Harbour at a rate of 10°85 miles per hour. The diminished velocity between Bowling Bay and Clyde Bank arises from the channel of the river being more crooked in that part than in any other portion of the River Clyde, thereby showing the great neces- sity of straightening and improving it. On the Theory of Waves. By the Rev. Professor KELLAND. The objects of the present communication are twofold : first, to pre- sent the subject of the Theory of Waves in its present form, and then to point out the difficulty which appears likely to impede its progress. 1. The object of the theory is to account, on mechanical considera- tions, for such phenomena as are presented by the destruction of equilibrium of a fluid, and to obtain and to interpret mathema- tical expressions which give the velocity, form, impulses, and other circumstances of the motion. Our problem, then, divides itself into two parts; 1, the determination of the conditions which are pre- sented by the nature of the fluid on the hypothesis that it is in motion ; 2, the investigation of the effects which will immediately follow the disturbance of equilibrium. The first of these problems alone pre- sents no considerable difficulty ; at least the difficulties are not such as to have deterred many writers from engaging to solve it. Laplace led the way, and was followed by Lagrange, Poisson, and others. As far as the author knows, however, all the writers on the subject con- fine themselves to two cases, viz. when the depth of the fluid is either very great or very small, in comparison with the length of a wave. Aided by their discoveries, he attempted, in a memoir read before the Royal Society of Edinburgh last year, and published in vol. xiv. of their Transactions, to supply the deficiency, and to obtain the equa- tions of motion of a regular set of waves, without imposing any restric- tion on the conditions. This was effected by assuming that a recipro- cating function can always be expanded in a series of sines and cosines of multiples of the space through which the whole series of values extends. This assumption, which is frequently made by Fourier and others, leads directly to the complete solution of the problem. The author has since applied himself to the completion of this part of the subject by solving the problem in cases in which the depth is variable, which had only been partially executed before. In the first place, he considers that case in which the depth is variable in the direction of the breadth, but uniform in that of the length. In his former memoir he contented himself with an approximate solution, founded on a particu- lar hypothesis. The results, approximate as they confessedly were, TRANSACTIONS OF THE SECTIONS. 51 agreed remarkably well with the experiments of Mr. Russell. His present more complete formule are such, that, for all cases in which the form of the canal is expressed by an equation between a power of y and a power of 2, they lead precisely to the results which he pre- viously obtained. One remarkable circumstance he pointed out, which is this; that if the form of the wave can be expressed by a single function, the velocity is the same in the middle of the canal as at the edges. Perhaps this apparently anomalous conclusion may arise from the circumstance that we assume the same form of wave to per- tain to all parts of the canal. Another result of his analysis is, that the height of the wave increases very rapidly as we proceed towards the edge of the vessel, to the detriment, as it would appear, of the height of the centre. i He next endeavours to obtain the motion of a wave in a canal, the depth of which is continually but slowly varying in the direction of the length. He here employs the method of the variation of parame- ters, and obtains the following results :— 1. That the length of the wave is in direct proportion to the depth. 2. That the velocity of transmission at any point varies as the square root of the depth. 3. The elevation of the crest of the wave varies reciprocally as the total depth of the fluid. Lastly, he discusses the problem which Messrs. Poisson and Cauchy had solyed for the particular case, where the depth is very small or very great. It is well known that these philosophers undertook the solution of this problem in competition for the prize offered by the French Institute. As neither of these memoirs is printed exactly as it was originally delivered in, it would be hard for us to draw any con- clusions from the judgement pronounced by the judges. We know that M. Fourier found fault with Poisson’s solution on the ground that the function was limited in its value. The prize was accordingly adjudged to Cauchy. The plan which Poisson adopts, it is very easy . to understand ; viz. he finds a solution of the general equation of wave motion, and arranges it so as to make it coincide with a formula given by Fourier, which expresses the relation between a function and a par- ticular value of the function. M. Cauchy, on the other hand, demonstrates a formula slightly dif- fering from Fourier’s, and by means of it, he tgo expresses the general function in terms of the particular. Now it happens that M. Cauchy’s formula does not render necessary any limitation as to the depth of the fluid. Indeed, M. Cauchy himself discovered this, and published it in a note, but he never, to the author’s knowledge, made any further use of it. Some of the results obtained by both philosophers, are found by the author to be true without all the limitations which they have imposed. But there is one point of the utmost importance, viz. the determination of the length of the wave, for which their results are not satisfactory. Those who are acquainted with the analysis employed by the philosophers to whom he has referred, will remember that the integrals to be obtained may, by arranging in different forms, be made E2 a 52 REPORT—1840. to express different motions. Thus the ondes dentelées, and the waves of constant transmission, are alike expressed, and their length is deter- mined in a function of the disturbance, &c. Now it appears to the author, that the same expansion which leads to the waves of constant transmission, ought, when the circumstances of the motion are assumed to be such as to admit of it, to lead also to the wave of solitary trans- lation. If it do not, then it would appear that the theorems of Fourier and Cauchy cannot give in terms of x a discontinuous function of the nature required, or such that its differentials with respect to # and y shall vanish at the same time. If, on the other hand, the theorems do suffice to express the requisite function, then shall we expect to find not the velocity only, but the complete form of the wave, which results from a given disturbance. We shall, in fact, be furnished with the length of the wave. It ought to be stated, that the author has sought in vain to deduce it from the equation which gives the velocity of transmission, and with as little success from the value of the discon- tinuous function which he used in his first memoir; but with the gene- ral formula itself, although he has not positively discovered the impos- sibility of discovering the thing sought for, he has yet found consider- able difficulties. The principal of these is the multitude of series which must be accurately summed before the equations can be formed. He was in consequence led to point out such difficulties to the Asso- ciation, with the hope that some member might take up the subject, and, by removing them, render the subject susceptible of application to the theory of the tides*. On the Agency of Sound. By Mr. Suanv. The author commenced his paper by remarks on the neglect mani- fested toward preserving or assisting cur hearing; and having laid down, in a series of propositions, his views regarding the origin and conduction of sound, observes, that it is difficult to reason on the operations of nature and the motions and influence of matter not per- ceptible to the eye. In the present case, however, we are enabled to judge partly by our ocular faculty and in part from our sense of hear- ing. ‘That the vibratory and undulatory or oscillatory motions are not only prevalent in the musical string, but in all matter in a state of agitation, is indicated by the following facts :—1st. In a musical string of a given diameter and tension, when set in motion, the extent of the undulations is in the ratio of the length of the string—each undulation gives out a distinct sound, conformable in duration to the extent of the undulation. @2nd. In the walls and ceiling of an apartment these principles of action are also equally apparent ; wherever there is an extended surface in any one place, the undulations are also extended, and these produce distinct sounds in the ratio of their extent. If the * At the request of the General Committee, Professor Kelland has under- ‘taken to draw up a report on this subject, to be presented to the Association. a TRANSACTIONS OF THE SECTIONS. 53 reflections of the human voice, by this means, be prolonged, the re- flection of one letter falls upon the original sound of another letter, and occasions as much derangement as if one syllable or word were intermixed with another syllable or word ; as one letter differs in sound from another letter as much as do syllables or words. This is one great and leading error in the construction of places for public speak- ing; and it is alone sufficient to show how fallacious the idea is of relying on the mere form of an apartment, without attending to and regulating this action, in not only the walls and ceiling, but in every reflecting body in an apartment, especially in glass, which is the most sonorous material. 3rd. The same rules of action are exhibited in water. In the ocean, the reach of sound is regulated according to the expanse of water: where there is an indent in the land, the wave is extended, and the sound it produces is prolonged. Were this action regulated by the current of air only, the waves would pass in one uni- form direction; but this is not the case. 4th. These principles of action are, however, more perfectly defined in the atmosphere, through which sounds are transmitted with least change, and are preserved separate and apart from each other. Having in view mainly the economy of speech in apartments, Mr. Shand stated the following facts and reasoning: An individual who is so deaf that he is insensible to upwards of a thousand people singing in a church, on applying one end of a forked piece of wood to his teeth, and the other end to the ledge of the division of the seat before him, is enabled by this to hear and join in the tune. Now it is not merely the partial agency of this wood that is to be considered, as, by the spread of the atmosphe- ric vibrations, the voice sets in motion every atom of every solid in the church, and it is distributed throughout these with more rapidity and intensity than by the air, which is incapable of communicating the same measure of vibratory influence at any one given point; and it evinces that, being the more rapid and profuse conductor, it is the wood that is most rapidly set in motion, and communicates action and sound to the air ina room. If these observations be correct, nothing can be more erroneous than to suppose that speech can be regulated within the walls of an apartment without regulating the action of the solids, which predominantly govern it in this case. If sound predomi- nates more in the fibre of the wood of the stethoscope than in the a€rial passage in it, must not the same rule apply in a church, where the seats and lathing are almost invariably of pine ? Mr. Shand proceeded to remark on the peculiarities with regard to sound which he had observed in certain buildings. In the Albion Church, in Glasgow, he heard the speaker with perfect distinctness when he spoke in his natural tone, as his voice was mostly reflected by the walls, which are of solid masonry ; but when his voice was raised so as to act with more force on the ceiling, the longer excursions and undulations of the then hollow ceiling produced prolonged reflections, which drowned speech. In St. Andrew’s Church very different effects are produced in the galleries and lower part of it. In the galleries the ceilings are 54 REPORT—1840. low and curved, and the voice, acting within the curvatures, produces prolonged and concentrated reflections (as in all such cases) inimical to speech ; the windows are much exposed to the voice, and the divi- sions of the seats rise too much above each other, all which occasion lengthened reverberations, to the prejudice of speech. The asperities presented by the ornaments on the walls, and the capitals of two ranges of Corinthian pillars, occasion harsh reflections, which are unpleasant. All these defects are, however, lost in a great measure in the lower part of the building, where little inconvenience is experienced. In Dr. Lee’s church, in St. Giles’s, Edinburgh, in which the General Assem- bly met, but were obliged to abandon it as their place of meeting, the arrangements are such that the preacher is very indistinctly heard at the distance of twenty feet, and there are two galleries at the extremi- ties of the church which are locked up as useless. Similar causes pro- duce similar effects in St. Luke’s Church in Liverpool. Here there is a locomotive pulpit, for the purpose of rolling the preacher from place to place ; but there is even a gross evil in this vehicle, which accom- panies it and the speaker to whatever point he may be conveyed. The canopy over his head is a deep hollow body, formed of thin deal ; it is literally a drum, as may be understood by striking it, and produces deep hollow sounds, operating in a transeverse direction, and most prejudicially on the voice of a speaker. The author notices several other cases, and states that it is not by creating additional or increa- sing reflected sounds, but by bringing the action of the reflecting sur- rounding solids to move in time with the mechanism by which speech is produced, and by this means, reflected sounds to accord with every distinct letter that the speaker pronounces; it is by shortening the action, and limiting the time of each distinct reflection from the glass, thin deal boards, &c., to the time in which each letter is formed by the speaker. This, in fact, however simple it may seem, must be effected, otherwise no form in the walls of an apartment for public speaking can accomplish what is necessary for the economy of speech. On a Method of approximating to the Value of the Roots of Numerical Equations. By Mr.Granam. On the Expressibility of the Roots of Algebraic Equations, By Mr. Peres. Since the function of the coefficients which expresses the general root of an equation must be such as to represent all the roots, the author seeks to discover that particular function of its quantities. After proving that various combinations will not suffice, he shows that certain others will do so in certain cases. TRANSACTIONS OF THE SECTIONS. 55 Notice of Mr. Fowler’s new Calculating Machine. Communicated by Professor Airy. The origin of this machine was to facilitate calculations of the pro- portions in which the several divisions of a poor-law district in Devon- shire were to be assessed. The chief peculiarity of the machine is, that instead of our common decimal notation of numbers, a ternary notation is used; the digits becoming not tenfold but threefold more valuable as they were placed to the left; thus, 1 and 2 expressed one and two as in common, but 1 0 expressed (not ten, but) three, 1 1, four, 1 2, five; but again 2 can be expressed by 3, with | taken from it. Now, let 1, written thus, with a small bar above it, mean that it is subtractive; then 1 2 and ¢ 1 are the same in effect, both meaning five ; and, for a similar reason, replacing 2 by its equivalent 1 1, we have five written in three several ways: 1 2, or 21, or 117; the last is the form used. It is obvious, that by an assemblage of unit digits thus posi- tively or negatively written, any number may be expressed. Thus the number which decimally expressed is 70, becomes in the ternary system 2121: and 2 being equal to 1 T, this may be made 10111. In the ma- chine, levers were contrived to bring forward the digits 1 or T, as they were required in the process of calculation. A full description of the machine, drawn up by Professor De Morgan, was presented by the author. On a Mode of solving Cubic Equations. By Mr. Wausu. New Logarithmic Calculations and Views. By Wm. Hovyte. On a new Construction of Barometer. By P. McFar.ane. The author proposed to substitute the weighing of a mercurial column, for the measure of its length, and by contrivances in accord- ance with this principle, to reduce or extinguish the dispreportion which exists between the common barometrical linear measures, and the variations of physical condition on which the change of these measures depends. On the four daily Fluctuations of the Barometer. By Mr. Esry. When the sun rises the air begins to expand by heat; this expansion of the air, especially of that near the surface of the earth, lifts the strata of air above, which will produce a reaction, causing the barome- ter to rise ; and the greatest rise of the barometer will take place when the increase of heat in the lower parts of the atmosphere is the most rapid, probably about 9 or 10 a.m. The barometer from that time will 56 REPORT—1840. begin to fall, and at the moment when the air is parting with its heat as fast as it receives it, the barometer will indicate the exact weight of the atmosphere. The barometer, however, will continue to descend on account of the diminishing tension of the air and consequent sink- ing upon itself as the evening advances ; and its greatest depression will be at the moment of the most rapid diminution of temperature, which will be about 4 or 5 o'clock. At this moment the barometer will indicate a less pressure than the true weight of the atmosphere. The whole upper parts of the atmo- sphere have now acquired a momentum downwards, which will cause the barometer to rise above the mean as the motion diminishes, which must take place some time in the night. This rise will be small, how- ever, compared with that at 9 or 10 am. As the barometer now stands above the mean, it must necessarily descend to the mean at the moment when it is neither increasing nor diminishing in temperature, which will bea little before sunrise. If this is the true explanation of the four fluctuations of the barometer in a day, it will follow that the morning-rise ought to be greater at considerable elevations, provided they are not too great, because some of the air will be lifted above the place of observation; and such was found to be the case by Col. Sykes in India. On the Meteorology of Perth. By Dr. ANDERSON. Perth is elevated about 30 feet above the mean level of the ocean, and situate in lat. 56° 23' 40" N., long. 3° 26' 20". W. Dr. Anderson stated that the magnetic variation, which seemed to have reached its maximum in 1815, was 26° 54’ W. in Nov. 1836; and that the mag- netic dip was 72° 10' in May 1838. The mean barometrical pressure, deduced from a period of six years of consecutive observations, con- tinued from 1829 to 1835, was 29°802, the time of observation being nine o'clock in the morning. By a comparison of the means of each month, for the several years, with the mean of the entire period, it ap- peared that the means in defect greatly exceeded those in excess ; from which he concluded, that the disturbing causes which produce a dimi- nution of atmospherical pressure are more sudden, as well as more powerful in their operation, than such as give birth to an opposite con- dition,—a result which implies that the causes contributing to a low state of the barometer are of limited extent and partial influence,— and may be explained by referring them partly to the diminution of aerial elasticity occasioned by a rapid condensation of aqueous vapour, and partly to the combustion, by electricity, of large portions of car- buretted hydrogen in the upper regions of the atmosphere over the place of observation. Hence he inferred that an arithmetical mean be- tween two observations, the one expressing the highest and the other the lowest height of the mercury, will rarely give the true average height for the mean interval of time between the observations. The mean annual range of the barometer at Perth, derived from a period of nine consecutive years, is 2189 inches; but the extreme i ie 2 a TRANSACTIONS OF THE SECTIONS. 5F. range for the same time, or the difference between the highest and lowest altitude of the barometer, was found to be 2°821 inches. The fluctuations or deviations from the mean state are greatest in December and smallest in August. The mean temperature of Perth, derived from the maxima and minima of each day, according to observations continued from the beginning of 1829 to the end of 1834 inclusive, is 48°14. The mean obtained from the annual means, by observations taken at nine o'clock in the morning, and half-past eight in the even- ing, is 47°9; and the mean of the annual extremes, derived from the greatest heat and greatest cold, for each year, is 48°25. Lastly, the mean of the highest and lowest temperature for the entire period of years is 47°-5. By a comparison of the mean temperature of the seve- ral months, it appears, that in different years the month of July pos- sesses the greatest uniformity of temperature, and the month of January the least. The temperature of March, April and May, especially that belonging to the last of these months, has a considerable range in dif- ferent seasons, on account of the variable winds in spring; and the temperature of August and September seems to be still more fluctua- ting, a circumstance that occasions the late and early harvests, which happen in different years. The lowest temperature, within the period to which the above observations refer, occurred on the 26th of Decem- ber, 1830, when the instrument stood at 16°, and the greatest heat took place on the 28th of July of the same year, when the thermome- ter was at 79°. The greatest annual range for that year was therefore 63°; but the mean annual range for the entire period was only 57°5. The most abrupt change of temperature occurs between the middle of October and the middle of November, and to this must probably be ascribed the increase of pulmonary complaints, which takes place at that gloomy and disagreeable season. The mean hygrometric state of the air at Perth, is when the atmosphere is charged with about four-fifths of the entire quantity of moisture it is capable of holding in the state of vapour at the mean temperature. The dew-point, which corresponds almost exactly with the minimum tempe- rature, in the case of the different months, is depressed about 6° or 7° below the mean temperature in winter, and about 8° or 9° below it in summer. The month of April possesses the smallest relative humidity, and the month of November the greatest; the former month being, in the ordinary acceptation of the term, the driest, and the latter the dampest month of the year. The mean quantity of rain which falls at Perth, de- rived from a period of six consecutive years, viz. from the beginning of 1829 to the close of 1834, is 30°89 inches. The greatest anomalies, with respect to the quantity of rain which falls in different seasons, hap- pen in July, in which month the difference between the greatest and least quantity is 4°65 inches ; and the smallest occur in November, when the difference is only *$1 inch. The maximum quantity of rain for a period of sixteen years is 31-01 in., and the minimum quantity 15-59 in. The annual number of fine days, deduced from a period of six conse- cutive years, is 253 ; and the number of days on which there was either rain or snow, 112; the former being more than double of the latier. - 58 REPORT—1840. CHEMISTRY. On the most important Chemical Manufactures carried on in Glasgow and the Neighbourhood. By Professor Tuomas TuHomson, of Glasgow, F.R.S. “ Glasgow being the seat of a great many interesting and important chemical manufactures, it occurred to me (said Professor Thomson) that it might be of advantage to those members of the Chemical Section, who have come from a distance, to give a short catalogue of the most important of these manufactures, that they might know what the information is which they may expect, and where they are to look for it.” 1. Lron.—The smelting of iron has been practised in the neighbour- hood of Glasgow for more than fifty years. When the late Mr. Dun- lop, of the Clyde Iron Works, first became proprietor of those works, perhaps the only one then in the neighbourhood, the produce was only fourteen tons a-week, or 728 tons a-year. At present the quantity of iron smelted in Glasgow and the neighbourhood cannot be much less than 200,000 tons, which approaches to a fifth part of the whole iron smelted in Great Britain. The ore from which the iron is smelted is the carbonate of iron, or clay iron-stone, as it is usually called by mineralogists. This ore is very abundant all round Glasgow, and especially in the neighbourhood of Airdrie, where the principal works are now situated. Fortunately for the smelters, the iron-stone and coal-beds are associated together, the iron-stone either occurring in nodules or beds along with the coal. The rapid increase of iron smelt- ing has been the consequence of a discovery of Mr. Nielson, manager of the gas-works. This is now universally known under the name of the hot blast. The air is heated to more than 607° before it enters the furnace, by passing through a range of heated pipes. Under this treatment, it is found that the coals may be used without previous coking ; and that instead of seven tons of coal for every ton of cast iron, three tons, or even two and a half tons will suffice. There is also a diminution in the quantity of limestone necessary, and the produce of iron per week from the same furnace is considerably increased. It is said, that neither in Staffordshire nor in Wales is the hot blast attended with the same saving of fuel. Till of late years, no bar iron was made in Scotland, the smelters confining themselves to cast iron. About three years ago, Mr. Dixon commenced the manufacture of bar iron near St. Rollox, but, after some time, he abandoned the manufactory. It is now conducted on a great scale, by Mr. Wilson, at Dundyvon, and by Mr. Dixon, at Glasgow, and perhaps by other iron-masters. The heat raised in the puddling furnace is much greater than it was in Staffordshire, when Dr. Thomson witnessed the process there about twenty-five years ago. There is an interesting manufactory of steel at Holytown, not far from Airdrie, where the smelting and casting of steel may be seen : the heat necessary for this process is greater than for any TRANSACTIONS OF THE SECTIONS. 59 other. It is curious, that the clay in the neighbourhood answers perfectly for making crucibles for cast steel; but it does not answer so well as Stourbridge clay for making glasshouse pots. On analysing the two clays, it was found that the Garnkirk contained much more alumina and less silica than the Stourbridge ; showing that glass in fusion acts more powerfully on alumina than on silica. 2. Another manufacture of importance, and which is indebted to Glasgow for the state of perfection which it has reached, is that of sulphuric acid. It was begun by Dr. Roebuck, at Preston Pans, about the year 1763, but it is not more than twenty years since his manu- factory was abandoned. The sulphuric acid works at St. Rollox, on the banks of the Monkland canal, were begun about forty-five yearsago. They were at first upon a very small scale, though they now probably are the largest of the kind in Europe. Dr. Roebuck’s method was to mix together sulphur and saltpetre, and after setting the mixture on fire, to introduce it into a leaden vessel or chamber, at the bottom of which there was a quantity of water. This method was not ceconomical. A portion of the sulphur would unite with the potash of the saltpetre, and form with it a sulphuret, and probably a portion of the sulphuric acid formed would also unite to the potash and form a sulphate. When Messrs. Knox, Tennent, and Macintosh established their works at St. Rollox, they separated the sulphur from the saltpetre ; the sul- phur was burnt over a stove, and an iron cup, containing the requisite quantity of saltpetre, mixed with the requisite quantity of sulphuric acid, was placed over the burning sulphur. By this contrivance the sulphur was completely converted into sulphurous acid, and the whole of the nitric acid carried along with it into the leaden chambers. The size of the leaden chambers was yradually increased, and the substitu- tion of steam for the water formerly placed at the bottom of the cham- bers, was a vast improvement. The acid which collects at the bottom of the chambers has now a specific gravity of 1°75, or it is a compound of one atom anhydrous acid, and two atoms water. This acid is con- centrated by heating it in a platinum still till the second atom of water is driven off. When this manufacture is at full work, the quantity of sulphuric acid made in it exceeds 300,000]bs. avoirdupois per week. When he first began to purchase sulphuric acid, about forty-five years ago, it cost 8d. per pound ; the present price is under a penny a pound. 3. One of the great purposes to which sulphuric acid is applied at St. Rollox, is the manufacture of bleaching powder, or chloride of lime, as it is now called. When the mode of bleaching by chlorine was introduced into Great Britain, by Mr. Watt, in 1787, the very offensive smell and deleterious effects of that gas upon the workmen, was a formidable objection to its use. Various methods were tried to remove this objection. It was found that if potash or soda was dissolved in the water before it was impregnated with the chlorine gas, the disagreeable smell was destroyed ; but, unfortunately, this addition destroyed at the same time the bleaching power of the gas. At last, Messrs. Knox, Tennent, and Macintosh discovered that if lime were mixed with the water before it was mixed with the gas, the disagreeable smell was 60 REPORT—1840. obviated, while the bleaching power still remained uninjured. They took out a patent for this discovery ; but it was infringed upon by the Lancashire bleachers; a law-suit was the consequence, and the patent was destroyed. It was then that Mr. Macintosh tried whether chlorine would not be absorbed by slacked lime. The trial succeeded: a com- pound was formed, which readily dissolved in water, and the solution of which possessed great bleaching power; a patent was taken out for the manufacture of this dry powder, which the patentees distinguished by the name of bleaching powder. This patent was not infringed ; the sale of it was at first small, and it was overlooked by the bleachers. The consequence was, that the patentees had leisure to perfect their method of preparing it, and to become able to sell it at so low a price, that it gradually superseded all the old methods of bleaching by chlo- rine. The process may be seen at St. Rollox in great perfection, and on a very large scale. The requisite mixture of common salt, binoxide of manganese and sulphuric acid, is put into a leaden still, and the chlorine evolved passes through leaden tubes into air-tight stone chambers, the bottoms of which are covered with a stratum of slacked lime several inches thick. The lime absorbs the gas as it passes into the chamber, and the process is continued till the absorption is reckoned sufficient. Bleaching powder, supposing it pure, is a com- pound of i: Chloridesof caleium) we taco wine F 25 Chiorite ofimerrn ois se '% Parte 10 SniWatertarSeisinerliet gikver! ohh eS 20°375 Half the lime loses its oxygen, and combines with chlorine, consti- tuting chloride of calcium. The oxygen combines with chlorine, which, in the state of chlorous acid, combines with the other half of the lime, constituting chlorite of lime. Two atoms of the water were in the slacked lime. The third atom must have come along with the chlorine gas, or been absorbed from the atmosphere. 4. After the chlorine has been extricated, there remains in the still a semi-liquid mass, consisting partly of the impurities of the manga- nese, and partly of sulphate of soda and sulphate of manganese. If the manganese were pure binoxide, and only the quantity of salt and sulphuric acid necessary for the decomposition were used, the sulphate of manganese (abstracting the water) would weigh nine and a half, and the sulphate of soda nine. But in order to save the stills by pro- ducing the decomposition with little heat, twice as much sulphuric acid is used as is necessary, and this excess is afterwards saturated by means of common salt; so that the quantity of sulphate of soda in the residue is at least twice as great as that of the sulphate of manganese. To get rid of the sulphate of manganese, the residue from the stills is fused in a reverberatory furnace at a red heat; this drives off the sul- phuric acid, and leaves the manganese in the state of sesquioxide. The whole is dissolved, and the insoluble manganese thrown away. The solution of sulphate of soda is evaporated to dryness, mixed with small TRANSACTIONS OF THE SECTIONS. 61 ° ‘coal, and fused again. This destroys the sulphuric acid, and converts the soda into sulphuret. This sulphuret being mixed with sawdust, &c., and exposed to an incipient red heat, the sulphur is driven off, and carbonate of soda remains, which is obtained in crystals by solution and crystallization, or in the state of soda ash, by a more rapid process. The theory of the last step of the process, in converting the sulphate of soda into carbonate, is not very obvious, and would require an ex- perimental investigation to throw light on it. 5. Another chemical manufacture, which may be seen, is alum- making. There are two establishments, one at the Hurlet, about six miles south-west, by the Paisley canal; another at Campsie, about eight miles off, near Kirkintulloch, on the Great Canal, and near the foot of the Campsie hills. The alum is made from the shale, which exists in great abundance in the exhausted coal beds. This shale is a clay mixed with some coal, and with that variety of iron pyrites, which undergoes decomposition, and is converted into sulphate of iron by exposure to the air. Thesulphate of iron, thus formed, acts slowly on the clay, and in process of time converts it into sulphate of alumina. The alum-maker washes this altered shale, and obtains a solution of sulphate of iron and sulphate of alumina. When suffi- ciently concentrated and cooled, the liquor yields an abundant crop of sulphate of iron, which is removed, dried, and sold at a cheap rate. The sulphate of alumina does not crystallize till it is mixed with sul- phate of potash or sulphate of ammonia; because alum is a double salt, composed of three atoms of sulphate of alumina and one atom of sulphate of potash, or sulphate of ammonia. Formerly, nothing but chloride of potassium, bought from the soap-makers, was used. But of late years (at least at Hurlet), sulphate of ammonia, from the liquor obtained during the preparation of gas, has been employed. In general, the alum made at Hurlet contains both potash and ammonia; but the manufacturer can supply it free from potash. Such alum is convenient to chemists, because when it is heated to redness, every- thing is driven off except pure alumina. At Hurlet and at Campsie the mode of concentrating the liquid by a current of heated air pass- ing over its surfaces, deserves attention. 6. At Campsie alum-works may be seen another interesting che- mical manufacture, the fabrication of prussiate of potash, a beautiful well-known yellow salt, which crystallizes in truncated octahedrons. It was here that the manufacture of this salt, on a great scale, first began. Before that time it was only prepared in laboratories for scientific purposes, and sold at a high price. Mr. Macintosh intro- ‘duced it to the calico-printers, who used it extensively, to produce very beautiful blues and greens. It is prepared by burning the hoofs and horns of cattle in iron pots, along with a quantity of potash. The hoofs and horns of a hundred head of cattle are consumed every day in the works. For some time no iron was added, the requisite quan- tity for forming the salt being corroded from the pots during the com- bustion. But the last time that the author visited the works, he found that iron was mixed with the hoofs, &c. during the combustion. The 62 REPORT— 1840. residue, after this combustion is lixiviated with water, and when the solution is sufficiently concentrated, the prussiate of potash crystal- lizes. Connected with this manufactory of prussiate of potash is another, of Prussian blue. It is made by mixing sulphate of iron, alum, and prussiate of potash, and precipitating the whole by an alkali. The precipitate is at first light blue. But it is washed with new portions of water every day for several weeks. At every washing the colour deepens, and when it has acquired the requisite shade, the Prussian blue is allowed to subside, the water is drawn off, and the powder allowed to dry. The colour varies according to the proportion of alum employed; and it has the finest colour of all, with the coppery lustre which is so much admired, when no alumina what- ever is mixed in it. 7. Another beautiful chemical product may be seen at Shawfield, near Rutherglen, about two miles from Glasgow, in the manufactory of Mr. White. Thisis bichromate of potash, a salt very much used by calico-printers, and forming the finest and most indelible yellows, oranges, and greens. Its introduction constituted quite an era in calico-printing. This salt was originally made by heating chromiron ore with saltpetre, dissolving out the chromate of potash, and adding the requisite quantity of nitric acid to deprive the chromic acid of half its potash. When this process began, the salt was sold at a guinea an ounce ; but now, when the price is as low as two shillings a pound, it is necessary to prepare it by a cheaper method. It has been found that common potash of commerce may be substituted for saltpetre ; and Dr. Thomson believes the manufacturers now contrive to form the bichromate at once, without requiring the use of an acid, which would nearly double the expense. It is stated that all the bichromate used by the calico-printers is made here and in Liverpool. In the same manufactory may be seen a beautiful product, tartaric acid, which is used by the calico-printers to a large amount, chiefly to disengage the chlorous acid from bleaching powder, and enable it to destroy the colour on particular parts of the cloth, either that these parts may remain white, or that some other colour may be superadded. Tartaric acid is obtained from cream of tartar, by throwing down the tartaric acid by means of lime, and afterwards decomposing the tartrate of lime by means of sulphuric acid, and crystallizing the tartaric. At the same manufactory may be seen a pretty and simple process, by which the carbonate of soda is converted into the sesquicarbonate. By simply exposing it dry, and in powder, in an atmosphere of carbonic acid gas, it absorbs the requisite quantity to be converted into sesqui- carbonate. And this sesquicarbonate is chiefly used by the makers of soda water. 8. It is hardly proper to mention the manufactory of acetie acid from wood, which has been carried on for many years by Mr. Turn- bull, because the first part of the process is carried on at a distance, the distillation of the wood. To free the acetic acid from the tar, which destroys its flavour and taste, the acid is combined with lime, and the acetate of lime exposed to a heat sufficiently high to char the TRANSACTIONS OF THE SECTIONS. 63 foreign bodies with which it is impregnated, the acetic acid being capable of resisting a higher temperature without decomposition than most compound vegetable bodies. The acetate of lime thus purified is decomposed by sulphuric acid, and the acetic acid obtained by distilla- tion. By this process it may be obtained very strong. The author possesses it composed of one atom acetic acid, and one atom water. When of this strength it crystallizes in winter, but becomes liquid again in summer. In the same manufactory there is another liquid prepared, namely, pyroxylic spirit, now well known. A most interest- ing set of experiments on it has been made by Dumas, who has di- stinguished its basis by the name of methylene, and has discovered various new compounds which it is capable of forming. 9. Another chemical manufacture of considerable importance, and which the author believes to be peculiar to Glasgow, is iodine. A few years ago there were no fewer than ten manufactories, in each of which it was made to a considerable extent; but as iodine is only used in medicine, the sale is necessarily limited, and most of these works are . nowabandoned. The process followed by all the makers was, Dr. Thom- son believes, the contrivance of Mr. Macintosh. Iodine is made from kelp, and it deserves attention, that those kinds of kelp that contain most potash, contain, at the same time, the most iodine. The kelp is lixiviated, and all the salts that can be extracted from the solution by evaporation are separated. The mother water remaining is now mixed with an excess of sulphuric acid. A great quantity of sulphuretted hydrogen is evolved, the bad effects of which on the workmen are obviated by setting it on fire, and allowing it to burn as it is extracted from the liquid. To the liquid thus freed from sulphuretted hydrogen and from muriatic acid, a quantity of binoxide of manganese, equal in weight to the sulphuric acid employed, is added. The whole is put into a leaden still, and heated to a temperature which must not exceed 190° or 200° at most. The iodine passes into the receiver, which con- sists of a series of spherical glasses, having two mouths opposite to each other, and inserted the one into the other. 10. It may seem superfluous to mention soap, because it is a manu- facture universally known; but soap of a very superior quality is made in Glasgow. The number of soap-works amounts to seven, and one of these, that at St. Rollox, is the third, if not the second, in point of extent, in Great Britain. The ingredients of soap are soda, tallow, and rosin, and sometimes palm-oil. Two kinds only of hard soap are made here, namely, yellow and white. The yellow soap is made by boiling 9°75 cwt. of tallow, 3°25 cwt. of rosin, 4 cwt. of soda ash, equivalent to 2 cwt. soda, mixed with the requisite quantity of water ; the white, by boiling 13 cwt. of tallow, 4 ewt. of soda ash in the same manner. Tallow, which isa compound of two oily acids and glycerine, undergoes decomposition, and the soda combines with the acid and forms soap. When the combination is complete, a quantity of common salt is put into the hot liquor. It dissolves in the water, and the soap separates, and swims on the top. It is now allowed to cool to 150° at an average, and then taken out in a liquid state, and poured into 64 REPORT—1840, frames, where it is allowed to become solid, and then cut into the usual parallelopipeds, or wedges, as they are called. It is customary, during the cleansing of the soap, as the pouring it into the frame is called, to mix it with a quantity of caustic soda ley. The soap made in Glasgow is usually a compound of 1 atom oily acid...... 53 or per cent. 74°6 2 atoms soda ......... 8 “4 11°2 9 atoms water ...... 10°125 °°, 142 71°125 White soap is cleansed at the average temperature of 181°. Its con- stitution is precisely the same as that of yellow soap. 11. Bleaching of cotton cloth is carried on here to a great extent. It consists of four processes :—1!st. The goods are boiled with lime, at a temperature above the boiling point of water. The process is curious, and deserves to be seen. 2nd. The cloth is steeped in a solution of bleaching powder. 3rd. It is boiled with caustic soda or potash. 4th. It is steeped in water acidulated with sulphuric acid. 12. Turkey-red dyeing has been practised here for almost half a century. 13. Calico-printing is carried on here to a great extent; glass-ma- king is carried on here or on the Clyde in all its branches; for starch- making there is only one manufactory. The manufacture of the dye stuff called cudbear, employed in dyeing red, has long been carried on here; so has the distillation of spirits and the manufacture of zther. On the Minerals in the Neighbourhood of Glasgow. By Professor Tuos. Tuomson, F.R.S. The neighbourhood of Glasgow, including Lead Hills, is not even inferior to Cornwall in the richness of its mineral species. The mines at Lead Hills began to be wrought during the reign of James IV. under the name of gold mines, and it is said by Boethius that he extracted from them a considerable treasure. In the time of James V. Lead Hills was a lead mine as at present, and is particularly described by Agricola in his celebrated work de re metallica. Besides galena, no fewer than nine species of lead ore occur at Lead Hills; these are— 1. Sulphate of lead. 2. Carbonate of lead, analysed by Klaproth in 1802. 3. Cupreo-sulphate of lead, described by Mr. Sowerby. 4. Sulphato-carbonate of lead, analysed by Mr. Brooke in 1820, 5, Sulphato-tricarbonate of lead, analysed by Mr. Brooke in 1820. 6. Phosphate of lead, analysed by Dr. T. Thomson. 7. Cupreo-sulphato-carbonate of lead, analysed by Mr. Brooke in 1820. 8. Chromo-phosphate of lead, analysed by Dr. T. Thomson. 9. Va- nadiate of lead, analysed by Dr. R. D. Thomson in 1834. Lead Hills also affords fine specimens of blende, or sulphuret of zine, and also of silicate of zinc. In Kilpatrick, hills, which bound the valley of the Clyde from the Stockey Muir to Dumbarton, and also the corresponding but lower TRANSACTIONS OF THE SECTIONS. 65 range on the south side of the valley, are composed of various trap- rocks, among which amygdaloid is pretty common. The cavities of this rock are filled up by crystallized minerals, most of them zeolites ; these are— 1. Stellite, first analysed by Dr. T. Thomson and Dr. R. D. Thomson. 2. Thomsonite, named by Mr. Brooke after Dr. T. Thomson. 3. Natrolite. 4. Mesolite. 5. Scolezite. 6. Laumonite. 7. Chabazite. 8. Analcime. 9. Cluthalite, first analysed by Dr. T. Thomson and Dr. R. D. Thomson. 10. Stilbite. 11. Heulandite. 12. Harmotome or Cross stone. 13. Carbo- nate of magnesia, at Bishoptown. 14. Dihydrous peroxide of iron, at Gou- rock. 15. Sulphate of barytes. 16. Calcareous spar. 17. Fibrous sulphate of lime. 18. Arragonite. 19. Wollastonite, first analysed by Dr. T. Thom- son and Dr. R. D. Thomson. 20. Prasolite, named by Dr. T. Thomson. 21. Fluor spar. 22. Prehnite. 23. Augite. 24. Amphibole. 25. Felspar. 26. Labradorite, one of the constituents of a variety of greenstone at Campsie glen, and at Gleniffer. 27, Mica. 28. Epidote. 29. Steatite. 30. Iron pyrites. 31. Carbonate of iron. 32. Gray ore of manganese. 33. Kilpatrick quartz, first analysed by Dr. T. and Dr. R. D. Thomson. 34. Sulphuret of cadmium, rare, and lately discovered, occurring along with prehnite at Bishoptown. Single crystals are now selling at 10/. each. It has been analysed by Dr. T. Thom- son and Mr. Connel. On the Relation of Form to Chemical Composition. By Dr. ScHAFHAEUTL. The author stated, that he had, in a former communication, given a new method of procuring graphite, in which it was also shown that all graphites owed their origin to the operation of the same causes ; namely, the contact of bitumen (or any similar substance) with a silicate, under a certain limited degree of heat; it was further maintained, that the compound nature of graphite might be satisfactorily demonstrated, by subjecting it to the action of hydrofluoric acid, which, combining with the silicon, liberated the carbon of the graphite as a hydruret, which was then consumed in the flame of alamp. The object of the present paper was to explain the circumstances under which certain modifica- tions of form take place in this peculiar substance (as also in others generally considered to be elementary), and to prove their connexion with changes of an entirely chemical nature. A beautiful specimen of a formation of graphite was exhibited to the Section, obtained from the Neath Abbey Ironworks, in South Wales ; it appeared to be composed of an infinite number of foliated scales overlapping each other, after the manner of the slates of a roof, each scale being so thin, as to be agitated by the slightest breath of air; a second specimen was exhibited of a graphite leaf, where it appeared as a globule of much greater size, the laminated structure still, however, existing in beautiful development. In a third stage, the scaly structure disappeared ; the globule having assumed a more porous and coke-like form. Dr. S. having premised an objection to any explanation of these curious changes of form, founded merely upon molecular alterations, proceeded to detail certain experiments, from which he deduced con- clusions of an interesting and important nature. 1840. F 66 REPORT—1840. The discovery of anew mode of decomposing crystallized graphite, by heating it in concentrated boiling sulphuric acid, and adding a little con- centrated nitric acid*, afforded a series of singular and instructive phzeno- mena. After the evolution of binoxide of nitrogen had ceased, each scale of graphite was converted into the globular substance before described ; its external metallic lustre remaining unchanged, but its bulk so greatly enlarged, that what before appeared a single scale, became, by the sepa- ration and division of its component laminz, a thick spongy tissue, capable of being restored to its former compressed foliated form by the pressure of the finger-nail. That this change of form, however, was not merely a mechanical effect, appears from the following experiment :—Graphite scales having been repeatedly treated with hydrochloric acid, washed, and again digested in a strong solution of caustic potash, in order to remove all possible mechanical admixtures of iron, silica and alumina, were then subjected to the process above described ; the evolution of binoxide of nitrogen having ceased, an equal quantity of water was added to the mixture ; immediately there succeeded a rapid evolution of bubbles from the globules of graphite, which at first lay at the bot- tom of the fluid; becoming lighter, as this evolution of bubbles pro- ceeded, they gradually rose to the surface, when the gas immediately ceased to be evolved ; the acid then, or the graphite, must have been combined with hyponitrous acid, which being decomposed by the water was disengaged as binoxide of nitrogen. The globules when washed, dried, and weighed (at first weighing but 2°01 grs.), had gained 5°02 grs. in weight. Being then put into a flat covered dish of brass, and balanced accurately, the cover was removed, the globules imme- diately lost weight, and so rapidly, that in merely removing them from the dish, 0°18 gr. were lost ; the dish was covered with a dew, appa- rently acid, as it acted on the brass. These globules, heated on paper until it became slightly tinged with yellow by the heat, now disengaged dense fumes, the paper being streaked with a blackish-coloured smoke where it was in contact with the graphite ; 2°30 grs. were lost during this process, which being repeated a second time, they were found to have lost 2°25 more. Finally ignited in a platinum crucible, dense fumes, without any perceptible odour, escaped, the weight of the globules being reduced to 1°86 gr. After which, no further reduction took place during the ignition for half an hour in the open air. The total loss of the two grains thus experimented upon with the acid, was 6°96. In a paper by the author‘, this loss was attributed to evolution of carbonic acid gas during this conjoined action of the acids; but it would appear from the last experiment, that there is formed a compound of sulphuric acid, nitric acid, carbon, hydrogen and oxygen, volatilized only at high tempera- tures. The question here arises, how can the rapid loss of weight be accounted for? During the previous drying process, which was con- ducted at 212°, the loss of water must have been accompanied by a change of chemical composition, and the new compound, by attracting * See a description in the Philosophical Magazine, vols. xvi., xvii. + See Philosophical Magazine, cited above. TRANSACTIONS OF THE SECTIONS. 67 water or oxygen when in the pan, must have formed an extremely vo- latile combination, evaporating as rapidly as it was formed. By a repetition of this treatment with the acid, graphite in the third stage, as before described, was obtained ; the metallic lustre was entirely lost, as also the laminated texture; it now appearing as a porous mass, re- sembling coke, and no longer capable of reduction to its original foliated state by pressure, having undergone a decided chemical change. The acid solution deposited at once a copious precipitate of silica and alumina (slightly tinged by oxide of iron), upon the addition of ammo- nia to neutralization. A similar precipitate was obtained from the acid of the first experiments, but less in quantity, and requiring a longer time for its operation. Thus it would appear that the abstrac- tion of silicon and the change of physical properties of graphite, are corresponding and mutually connected phenomena. In further proof of the necessary connexion of silicon as a chemical combination, essen- tial to the existence of the scaly metallic lustre of graphite, it will be found that by repetition of the same experiments, the globules ultimately disappear, and the remaining solution in acid neutralized by ammonia, deposits only flaky silica, with traces of oxide of iron. On observing attentively the specimen of graphite, as found in its natural state, and comparing it with those treated with acids and alkalies, also exhibited, it appeared that the scales, before being operated on, had a dirty gray- ish appearance, described as owing to their being covered with spots, consisting of microscopic six-sided flattened prisms of silicate of iron ; the matrix of this graphite formation, in the blast-furnace cinder, es- sentially composed of bisilicate of lime and alumina, deriving a yellow- ish tint from a slight admixture of sulphuret of calcium, with a trace of sulphuret of potassium. Scales of very different density may be separated, the thinnest unaffected by the magnet, the thicker ones decidedly so; those in the middle of the mass, thicker and stiffer, not easily broken, and showing a shining black fracture, like that of an- thracite, form a variety of graphite, in which silicon and iron are greatly predominant, developing when treated with hydrochloric acid a fetid hydrogen characteristic of cast iron, and separating at the same time yellow flocks of silica and alumina. Dr.Schafhaeutl then proceeded to point out an analogy between the formation of gray iron in the blast furnace, and that of graphite; namely, that the same chemical condi- tions occur during the change of white iron into gray ; this takes place after having descended through the furnace, and reached the stratum of slag covering the melted metal; this slag being an earthy bisilicate (in coke furnaces approaching to a trisilicate), and containing a small quantity of protoxide of iron. As silicon is found in graphite only in very small quantity, it has been considered an accidental impurity, just as the small quantity of hydrogen retained by charcoal, sulphur, &e. has been considered an impurity; but as these foreign matters can by no chemical means be separated, without destroying the state in which graphite, charcoal and sulphur exist, it must be inferred that such admixture is essential to their existence in that state in which they ordinarily appear. Quitting now the individual consideration of gra- F2 68 REPORT—1840. phite, the author extended the principle here argued to certain other substances, considered generally as simple bodies. For example, sul- phur obtained by the decomposition of sulphurets by acids, is white in colour, and invariably combined with a stable quantity of hydrogen ; but obtained from hyposulphites, it is as invariably yellow, and the presence of free hydrogen in the slightest quantity bleaches the pre- cipitate. The known case of sulphur precipitated under the presence of sulphuretted hydrogen, and cautiously mixed with metallic copper in its utmost state of minute division, being found to combine directly, evolving a dull red heat, has been considered an exception to the law, that no two dry bodies unite without the intervention of a third; but sulphur precipitated from hyposulphites, will not thus combine, nor will pure sulphur, though subjected to the minutest division possible. The same sulphur, however, brought into contact with hydrogen, under a pressure of four atmospheres, and then quickly mixed, is found to com- bine, as in the first instance; but if exposed to the air, its power of combination is again lost; thus a third body is proved necessary here, as in all cases. And further, the author doubted if one of the two different crystalline forms of sulphur is not owing to the presence of hydrogen, which he found to be in combination with it in a very per- ceptible quantity. These peculiar forms of combination, where a few atoms of one body are combined with a high number of atoms of an- other, may be considered, perhaps, as forming a class of compounds intermediate between the inorganic and the higher organic compounds : thus the compounds of arsenic acid form a very striking example. In the subarseniate of iron, 50 atoms of iron are combined with only 3 atoms of arsenic acid and 75 of hydrogen. So again, 24 atoms of arsenic with 1 atom of sulphuret of potash in sulph-arseniate of potash. By gradually passing from compounds of inorganic chemistry to those of organic chemistry, we find di-acetate of copper with water, 48 atoms of oxide of copper combined with only 1 atom of hydrogen and 12 atoms of water. And finally, in the field of organic chemistry itself, we have, for example, margaric acid, composed of 67 atoms of hydrogen, 35 carbon, and 3 of oxygen only. In the oleic acid, 120 atoms of hydrogen are combined with 70 of carbon and 5 of oxygen; in the stearic acid, 134 atoms of hydrogen with 70 of carbon and 5 of oxygen, &c. The author hinted in his paper in the Philosophical Maga- zine, thatthe principal circumstance which tended to produce compounds of such multiplicity of atoms, or, in fact, organic compounds, was the se- paration of the molecules of bodies brought into action by the capillary powers of the vessels of organic structures. It was probable that the che- mical action of these separated molecules must be a different one from their action, when arranged into one definite form; and as proof that once-received laws of affinity were exhibited only under peculiar cireum- stances, he directed the attention of the Section to H. Rose’s compound, formed by direct combination of 29°97 per cent. of ammonia with 70°03 per cent. of sulphuric acid, which ought to have produced anhydrous sul- phate of ammonia; but after combination, neither sulphuric acid nor ammonia could be detected in the compound. The same chemist found TRANSACTIONS OF THE SECTIONS. 69 combinations of anhydrous sulphuric acid with the chlorides of ammo- nium, potassium, sodium, and the nitrate of potash. According to the laws of affinity, for example, in the last case, the nitric acid ought to have been displaced, decomposed, and driven away by the more pow- erfully acting sulphuric acid; but no tendency whatever was shown to the displacement of chlorine or nitric acid, and new compounds, differ- ent from all hitherto known, resulted. As no combination of anhy- drous sulphuric acid took place at all with oxide of calcium, chloride of barium, or chloride of copper, he concluded that these above- mentioned combinations were formed only by replacing one double atom of hydrogen, water, or chlorine, in order to form a bisulphate of potash, soda, or ammonia. The author seemed to believe that there existed two different states of chemical combination ; the first, in which the chemical forces of molecular attraction were acting only according to the relative quantities of matter; the second, where, under the | always catalytic presence of a third, the elementary substances arranged themselves, separating in groups according to the resultant electric forces of the centres of action created by the above-mentioned presence of a third, acting differently on the different molecules of bodies in contact, in a somewhat similar way as a solution, which does not cry- stallize unless the molecular equilibrium of the liquid is disturbed. The first state of chemical combination might, perhaps, have some distant relation to Dumas’s law of types; the second state, a mere con- sequence of the first, would be represented by Berzelius’s electro- chemical combination. The author, at the same time, referred to Prof. Graham’s admirable papers, in which the Professor had so di- stinctly pointed out the great and peculiar part which water performs in chemical solid combinations, and remarked, that during all chemical combinations where a third body is separated, the precipitation only would take place when a certain quantity of water combined with the body to be precipitated, which water separated in the relation to the separation and. consolidation of the precipitate only, and could be driven away from it only by applying a red heat. New Compound of Arsenious and Sulphuric Acids. By Dr. ScHAFHAEUTL. This was obtained from the escaping smoke of copper calcining furnaces near Swansea, in South Wales. The new. compound was another singular instance where an anhydrous crystallized body was deposited under the presence of water only, and was a remarkable proof of the unlimited number of different forms of combination, which might be produced even in inorganic nature, by bringing chemical substances in contact under varying circumstances. The copper ores smelted in South Wales were, for the greatest part, copper pyrites, mixed with iron pyrites, gray copper ore, &c.; in fact, a mixture in which the sulphurets of copper, iron, arsenic, antimony, cobalt, nickel, zinc, and tin were invariably found together. The sulphur and arsenic escape from these ores during the calcining process, as 70 REPORT— 1840. sulphurous and arsenious acids, and have been found to destroy all vegetation for miles around the copper works, without affecting animal life in the slightest degree. By bringing the escaping fumes in contact with steam, and forcing it through burning charcoal, or subjecting it only to a great pressure in contact with steam, the new solid compound was deposited on the cool surfaces of the chambers connected with the calcining furnace. It was deposited in beautiful erystallized leaves or tables, perhaps belonging to the same class as Wohler’s dimorphic modification of the crystallization of arsenious acid, the regular form of which belongs to the octahedron. It was found to consist, in 100 parts, of 68:250 Arsenious acid. 27°643 Sulphuric acid. 3°029 Protoxide of iron. 0-420 Oxide of copper. 0°656 Oxide of nickel. 99:998 Corresponding to 51-741 Metallic arsenic. 11:095 Sulphur. 2°339 Iron. 0°336 Copper. 0°516 Nickel. 33°971 Oxygen. 99-998 These crystals attracted moisture from the air with great rapidity and with evolution of heat, corroding animal and vegetable substances as powerfully as concentrated sulphuric acid. Their taste was pure, but powerfully sour, similar to sulphuric acid, and, dissolved in water, the remainder of 100 parts of these crystals was 17-436 grains only. The shape of the crystals was perfectly retained, only their appearance was changed from transparent into opake. Their chemical composition was found to be, 16°778 grains of Arsenious acid. 0°656 Oxide of nickel. 17°434 What the water had dissolved consisted of 51°472 Arsenious acid. 27°643 Sulphuric acid. 3:029 Protoxide of iron, 0-420 Oxide of copper. 82-564 grains. One of the remarkable changes during the formation of this com- pound, was the conversion of sulphurous acid into sulphuric acid, as well as the presence of iron, copper, and nickel in a deposit from gaseous matter. No other definite compound of arsenic acid with another acid seems to be known, except those with the organic tartaric and paratartariec acids. by TRANSACTIONS OF THE SECTIONS. 71 On a New Method of Photogenic Drawing. By Dr. ScHAFHAEUTL. After some observations on the comparatively low value of all draw- ings taken by means of the camera-obscura, in an artistical point of view, and on the principal points on which Mr. Talbot's and M. Daguerre’s methods of fixing the drawings of the camera-obscura were founded, the author proceeded to describe his peculiar methods of producing photogenic drawings in Mr. Talbot's, that is, in a negative way; then, secondly, he described two new methods of obtaining photographs in a positive way. His first method tended to obtain a paper of very great sensibility by a comparatively short process. He recommended Penny’s improved patent metallic paper, and spreading a concentrated solution of the nitrate of silver (140 grains to 24 drachms of fused nitrate to six fluid drachms of distilled water), by merely drawing the paper over the surface of the solution contained in a large dish. In order to convert this nitrate of silver into a chloride, the author exposed it to the vapours of boiling muriatic acid. A coating of a chloride of silver, shining with a peculiar silky lustre, was by this method generated on the surface of the paper, without penetrating into its mass; and in order to give to this coating of chloride the highest degree of sensibility, it was dried, and then drawn over the surface of the solution of the nitrate of silver again. After having been dried, the paper was ready for use; and no repetition of this treatment was able to improve its sensitiveness. ‘The author’s process for fixing definitively the drawing was as follows:—He steeped the drawing from five to ten minutes in alcohol, and after removing all superfluous moisture by means of blotting-paper, and drying it slightly before the fire, the paper thus prepared was finally drawn through diluted muriatic acid, mixed with a few drops of an acid nitrate of quicksilver, into the minutiz of the preparation of which we cannot here enter. The addition of the nitrate of mercury requires great caution, and its proper action must be tried first on paper slips, upon which have been produced different tints and shadows by exposure to light; because, if added in too great a quantity, the lightest shades disappear entirely. The paper, after having been drawn through the above-mentioned solution, is washed well in water, and then dried in a degree approaching to about 158° Fahr., or, in fact, till the white places of the paper assume a very slight tinge of yellow. The appear- ance of this tint indicates that the drawing is fixed permanently. The author’s way for reversing the drawing is, in the principal points, the same as that suggested by Mr. Fox Talbot. In order to obtain a photogenic drawing in a direct or positive way, the author uses his above-mentioned paper, allows it to darken in a bright sunlight, and macerates it for at least half an hour in a liquid, which is prepared by mixing one part of the already described acid solution of nitrate of mercury with from nine to ten parts of alcohol. A bright lemon-yellow precipitate, of basic hyponitrate of the protoxide of quick- silver, falls, and the clear liquor is preserved for use. The macerated paper is removed from the alcoholic solution, and quickly drawn over the 72 REPORT—1840, surface of diluted hydrochloric acid (one part strong acid to seven or ten of water), then quickly washed in water, and slightly and carefully dried in a heat not exceeding 212° of Fahr. The paper is in this state ready for being bleached by the rays of the sun; and in order to fix the obtained drawing, nothing more is required than to steep the paper a few minutes in alcohol, which dissolves the free bichloride of mercury. The maceration must not be continued too long, as in that case the paper begins to darken again. The author’s second method of producing positive photogenic draw- ings was by using metallic plates, and covering them with a layer of hydruret of carbon, prepared by dissolving pitch in alcohol, and col- lecting the residuum on a filter. This, when well washed, is spread as equally as possible oyer a heated even metallic plate of copper. The plate is then carbonized in a close box of cast iron, and, after cooling, passed betwixt two polished steel rollers, resembling a common copper- plate printing-press. The plate, after this process, is dipped into the above-mentioned solution of the nitrate of silver, and instantly exposed to the action of the camera. The silver is, by the action of the rays of the sun, reduced into a perfect metallic state, the lights are expressed by the different density of the milk-white deadened silver, the shadows by the black carbonized plate. In a few seconds the picture is finished ; and the plate is so sensitive, that the reduction of the silver begins even by the light of a candle. For fixing the image, nothing else is required, except dipping the plate in alcohol mixed with a small quantity of the hyposulphite of soda, or of pure ammonia. On Poisons, Contagions, and Miasms. By Professor Liestc. Dr. Playfair stated that he had prepared, at the request of the author, a statement of Professor Liebig’s new views on the subject of poisons. Poisons might be divided into two classes, belonging to the inorga- nic and organic kingdoms. Many substances were called inorganic poisons which had in reality no claim to be considered as such. Sul- phuric, nitric, and muriatic acid, when brought in contact with the animal ceconomy, merely destroyed the continuity of the organs, and might be compared, in their modus operandi, to the action of a heated iron, or a sharp knife. But there are others—and these are the true inorganic poisons—which entered into combination with the substance of the organs without affecting any visible lesion of them. Thus it is known, that when arsenious acid or corrosive sublimate is added to a solution of muscular fibre, cellular tissue, or fibrin, these enter into combination with them, and become insoluble; when they are intro- duced into the animal organism the same circumstance must happen. But the bodies formed by the union of such poisons with animal sub- stances are incapable of putrefaction; they are incapable, therefore, of effecting and suffering changes; in other words, organic life is de- stroyed. The high atomic weight of animal substances explains the ¢ause of such small quantities being requisite for producing deadly TRANSACTIONS OF THE SECTIONS. 73 effects. After stating several chemical details on this subject, it was shown that to unite with 100 grains of fibrin, as it exists in the human body (in which it is combined with 30,000 parts of water), only 32 grains of arsenious acid are necessary, or 5 grains of corrosive subli- mate. The second class of poisons were those belonging to the organic ‘kingdom. For some such substances as brucia and strychnia, no data exist by which it can be determined to what cause their action may be assigned. But the morbid poisons, such as putrid animal and con- tagious matter, appear to owe their action to a peculiar agent, which exerts a much more general and powerful action than chemists are aware of. Thus, when oxide of silver is thrown into peroxide of hy- drogen, the oxide is reduced and metallic silver remains. Here there can be no affinity, for oxygen can have no affinity for oxygen. It is merely that a body in a state of motion or decomposition is capable of inducting or imparting its own state of motion or decomposition to any body with which it may be in contact. There is a disease frequently produced in Germany by using decayed sausages as an article of food. The symptoms attending the disease are remarkable, and distinctly indicate its cause. The patient afflicted with the disease becomes much emaciated, dries to a complete mummy, and finally dies. The muscular fibre, and all parts similarly composed, disappear. The cause of the disease evidently is, that the state of decomposition in which the component parts of the sausages are, is communicated to the con- stituents of the blood, and this state not being subdued by the vital principle, the disease proceeds until death ensues. It is remarkable that the bodies of the individuals who have died in consequence of it are not subject to putrefaction. The cause of the action of contagious matter is similar. It is merely a gaseous matter in the state of transformation, and capable of impart- ing the state of transposition in which its atoms are to the elements of the blood. It is capable of being reproduced in the blood just as yeast causes its own reproduction in fermenting wort. The causes of the action of yeast and of contagion were shown to be the same, and ex- amples were produced in which similar reproductions take place in common chemical processes. There are two kinds of yeast used in the brewing of Bavarian beer. The fermentation caused by one is tumul- tuous, that produced by the other is tranquil. They, therefore, induct the peculiar state of transposition in which their atoms are upon the elements of the sugar. ‘The same was shown to be the case with the vaccine virus of cow- and small-pox; the one of which produces a violent action upon the constituents of the blood, whilst the other causes a gentle action quite distinct from the former. On the Pre-existence of Urea in Urie Acid. By Professor Grecory. By the action of peroxide of lead on uric acid, Liebig and Wéhler obtained from it oxalic acid, allantoine and urea; and they considered the latter as existing in the uric acid combined with urile. The author, 74 REPORT—1840. having found that urea, unlike most organic substances, resists the oxidizing agency of permanganate of potash, thought that if urea could be obtained from uric acid by the action of that salt, the argument for its pre-existence would be much strengthened ; as, if only the elements of urea were present, the oxidizing agency of the permanganate would most likely prevent its formation. On trying the experiment a large quantity of urea was obtained, along with oxalic acid, and a new acid, probably formed by the oxidation of allantoine. The author further described the acetate of urea, a salt which was formed in his experi- ments. On a New Process, communicated by Prof. Liebig, for preparing Murexide. By Professor GRrcory. The process described in this communication for preparing the very singular and beautiful compound, termed murexide by Liebig and Wohler, and purpurate of ammonia by Prout, is quite certain, and very productive. It consists in adding a boiling solution of seven grains of alloxan and four grains of alloxantine in 240 grains of water, to 80 grains of a cold and strong solution of carbonate of ammonia. The mixture instantly acquires a deep purple colour, and on cooling de- posits the golden-green crystals of murexide. On the Preparation of Alloxan, Alloxantine, Thionurate of Ammonia, Uramile, and Murexide. By Professor GreGory. To prepare alloxan from uric acid, Liebig and Wohler used nitric acid, sp. gr. 1°42, and separated the acid liquid from the crystals by means of a porous brick, thus losing the whole mother liquid. The author uses nitric acid of sp. gr. 1°35. The action of this acid on uric acid must be kept moderate. When crystals of alloxan are formed, the whole is thrown on a filter, the throat of which is stopped with asbestus. That portion of the acid liquid which remains in the crystals is displaced by a few drops of cold water, and the crystals are purified by re-crystallization. The liquid is again employed in the same way, and the crystals are collected as before. Five such operations may be performed with the same liquid, each yielding a large crop of erystals ; while the mother liquid is preserved, and yields a large quantity of parabanic acid, or oxalurate of ammonia. By this process the author obtains from 100 parts of uric acid, 65 of anhydrous alloxan, or 90 of alloxan + 6 aq. From alloxan, alloxantine is easily obtained by the action of sulphuretted hydrogen. Thionurate of ammonia is easily formed, by boiling a solution of alloxan with sulphite of ammonia and free ammonia. Uramile is also easily obtained, by boiling a solution of thionurate of ammonia with an excess of diluted sulphuric acid. Murexide is obtained, as described in another communication by Prof. Gregory. He now exhibited the last three processes. He also stated, that the theory of the formation of murexide was of great importance in reference to organic colouring matters. Ld TRANSACTIONS OF THE SECTIONS. 79 Process for Preparing Hydrobromic andHydriodic Acids. By Dr. R. W. Grover, of Newcastle. Dr. Glover having observed that the solid bromide and iodide of barium are decomposed by sulphuric acid, with the evolution of hydro- bromic and hydriodic acids, without bromine or iodine being set free, proposed the employment of these salts of barium as very convenient sources of the above-named hydracids in atomic proportions. On a Method of separating, by Filtration, the Coagulable Lymph from Liquid Human Blood. By Prof. ANDREW BUCHANAN. Dr. Buchanan showed several specimens of coagulable lymph sepa- rated by filtration from human blood while yet liquid, immediately after issuing from the vein. He thought the process for obtaining it might not be without interest to those engaged in the prosecution of animal chemistry, as it enabled them to obtain the fibrin of the blood in a per- fectly pure state; and he knew no other process by which it could be so procured. The result obtained was also interesting, as serving to illustrate the constitution of the blood itself. It showed the coagulum to be formed not by the mere aggregation of the red particles, but that, according to the views of Berzelius, and many physiologists in our own country, the red particles were altogether passive in the act of coagu- lation, and were merely mechanically enveloped by the coagulable lymph, which existed in the liquid state in the blood as it circulates in the blood vessels. Dr. Buchanan’s process consisted in mingling toge- ther one part of liquid blood just drawn from the vein with six or eight parts of perfectly pure serum obtained from blood drawn the day before. Certain precautions are indispensable to the success of the experiment. If the blood be at once mixed with the whole of the serum, the red particles of the blood pass through the filtering paper along with the lymph and serum. Advantage must be taken of the superior specific gravity of the red particles in order to separate them. For this purpose, the liquid blood mixed with only a small quantity of serum is cautiously added to the rest of the serum placed in the funnel. The red particles subside, while the lymph mingles with the serum, and filtrates perfectly pure through the layer of red particles at the bottom, just as we filter any liquid through a stratum of sand. The mutual action of serum and liquid blood has not been sufficiently investigated. _ It has, indeed, been long known to physiologists, that the serum of the blood has no action upon the red particles, and they have employed it in their examination of the red particles under the microscope. They _ do not, however, appear to have pursued the inquiry further, to ascer- _ tain what becomes of the “ liquor sanguinis,” as it has been called, the _ transparent part of the blood as seen by the microscope, and of the fibrin which it holds in solution. To ascertain this, various proportions of serum and liquid blood were mingled together. When equal mea- sures of the liquids were used, or two or three parts of serum to one of blood, the coagulum formed was merely more voluminous and 76 REPORT—1840. looser in texture than usual, but not otherwise altered in appear- ance. When, however, six or eight parts of serum are employed, the coagulation is much retarded, the red particles form a dense layer at the bottom of the vessel, while the whole fibrin coagu- lates alone, forming a voluminous translucent mass,—an artificial “buffy coat,” as it would be called by physicians. In this way, how- ever, the fibrin is not obtained pure, but has more or less of a red tinge, particularly in the lower half of the mass, owing to the red par- ticles not having completely subsided before the coagulation took place. The results corresponded to what the author had anticipated, but he had no expectation of being able to obtain the fibrin perfectly pure by filtration, as Miiller had done with respect to the blood of the frog. Of the four specimens exhibited by Dr. Buchanan, one consisted of the red particles gradually deposited, while the fibrinous coagulum, with only a slight tinge of red at its lower part, floated above; the other three consisted of fibrin separated by the filter, one of the masses floating in serum, the other two in water. These masses are very like calf-foot jelly in appearance. They are of a cellular texture, and their ellow colour is owing to the serum contained in their meshes, but by ablution with water they become of a pure white colour. On the Constitution and Products of the Distillation of Fat Bodies. By Professor RepTENBACHER and Dr. VARRENTRAPP. The object of this paper was to show that the composition of the fat acids has hitherto been erroneously stated. A variety of acids were subjected to examination, such as stearic, margaric, oleic and sebacic acid. Margaric and stearic acids were shown to possess the same radi- cal; the former being the higher, the latter the lower oxide of it. This radical has the formula of C,, H;3, and may be represented by the symbol Ma; thus stearic acid is 2 Ma + 5 O, whilst margaric acid is 1Ma +30. They thus resemble sulphuric and hyposulphuric acids. Margaric acid is one of the products of the distillation of stearic acid ; the oxidation of the latter also causes the formation of the former. Oleic acid was analysed by these gentlemen, having been obtained in a pure state. The results were principally numerical, and are stated in Liebig’s Journal for 1840. On a New Fat Acid. By Dr. L. Puayrair. Dr. Playfair had examined some of the vegetable fats, for the pur- pose of ascertaining whether the margaric acid contained in them pos- sessed a constant composition. He remarked that the acid in the butter of nutmegs was peculiar, and had not formerly been examined. Pelouze and Bondet have stated in the Annales de Chimie, that it is — margaric acid. Dr, Playfair considered that the radicals of serecic and cenanthic acid were similar; in the former, however, one equivalent of TRANSACTIONS OF THE SECTIONS. 17 hydrogen is replaced by one equivalent of oxygen. It is a beautiful white crystalline compound melting at 49° ¢., and is soluble both in alcohol and zther. The combination of the acid with oxide of glyceril exists in the butter; it unites with metallic oxides and forms salts: these were described, but the results are not susceptible of analysis, as they were principally numerical. The formula of the acid is C,, H,, O;. On a New Mode of estimating Nitrogen in Organic Analysis. By Professor Bunsen, of Marburg. The qualitative methods at present employed for the analysis of azotized bodies were shown to be defective; for it is impossible to employ these processes when the nitrogen and the carbon are in small proportions to each other. Professor Bunsen’s process consists in in- troducing the substance to be analysed, after having mixed it with oxide of copper, into a glass tube. A few slips of metallic copper are then added, and the tube is fixed to Dobereiner’s apparatus for produc- ing hydrogen. This gas is conducted through it until all the atmos- pheric air is expelled, the tube having given to it a rotatory motion at the same time, in order to dislodge any air which might be retained be- tween the particles of the oxide of copper. The tube is now hermeti- cally sealed, and introduced into an iron vessel filled with gypsum. The gypsum must be still moist when the tube is introduced, in order that it may be firmly wedged. Thus prepared, it is introduced into the common oven used for organic analysis, and surrounded with red-hot coals. If the tube be of strong green glass it never bursts. When the combustion is completed the tube is placed below a graduated glass receiver standing over mercury, and the point cut off. The gas, which had a pressure of several atmospheres, now rushes into the jar. The carbonic acid is absorbed by a ball of hydrated potash, which is intro- duced into it, and the remaining gas must be nitrogen, for all the hydrogen must have been converted into water by the oxygen of the oxide of copper. The results obtained by this method agree with theory to the second, and often to the third decimal place. On the Compound or Radical called Kakodyl. By Professor Bunsen, of Marburg. The object of this paper was to describe a new radical resembling alcohol, in which arsenic replaced the oxygen of that compound. This radical enters into numerous combinations, forming, with oxygen, a peculiar acid, called kakodylic acid. The oxide of kakodyl has so great an affinity for oxygen, that when exposed to the air it imme- diately inflames. The bodies produced by the combustion are arseni- ous acid, carbonic acid, and water. By the further oxidation of the oxide of kakodyl, kakodylic acid is produced. The sulphuret of kakodyl is similar in composition to the oxide, and participates in many of its properties. The telluret, selenuret, iodide and bromide of kakodyl 78 REPORT—1840. were also examined. The danger attending these experiments is very great, and the poisonous effects produced by the inhalation of the vapour were described as dreadful. Kakodyl is produced from the liquor of cadet, and is extremely interesting as being a link connecting organic and inorganic chemistry. Professor Bunsen is engaged in further experiments on this subject, and has already obtained many new combinations. On the Identity of Spiroilous and Saliculous Acid. By Dr. Etr.inc. The oil discovered by M. Pagenstecher, and obtained by the distil- lation of the Spirea Ulmaria, has already attracted considerable atten- tion. Dr. Ettling had analysed it previously to the appearance of M. Piria’s valuable paper on Salicyl. The oil decomposes into two oils on keeping, one of which is specifically lighter, the other heavier than water. Dr. Ettling discovered that the latter possessed the same com- position as hydrated benzoic acid. The action of ammonia on the oil gives rise to some new interesting compounds. In order to obtain these compounds it is indifferent whether saliculous or spiroilous acid be employed. The final product of the action of ammonia upon these is the amide of salicyl (salicylamide). This body evidently belongs to the class of amides, for it does not evolve ammonia, on the addition either of potash or of acids. The cause of its formation is as follows: three atoms of saliculous acid unite with three atoms of ammonia, and form saliculite of ammonia, whilst three of hydrogen and oxygen com- bine together and form water. This salicylamide unites with copper, iron, and lead, forming compounds. On a New Method of Preparing Morphia and its Salts. By Dr. Monr, of Coblentz. The plan adopted by the author for separating morphia from narcotin and all other heterogeneous substances, consists in dissolving it in an excess of caustic lime, and precipitating it by muriate of ammonia. This method of precipitation is, in principle, very similar to the pre- cipitation of alumina from a solution of caustic potash. The process is as follows:—The opium is boiled in water, in which it readily dis- solves; the decoction is strained through a linen cloth, and the dregs are pressed; this operation of boiling and straining is repeated twice on the same quantity of opium, and the solution of the whole concen- trated until its weight is four times that of the opium employed. The concentrated solution is, while still warm, mixed with milk of lime, prepared with a quantity of dry lime equal to the fourth part of the weight of the opium. The mixture is heated till it boils, and is filtered through linen while hot. ‘The filtered liquor has a light brown yellow colour. While still hot it is mixed with pulverized sal-ammoniac in excess; the lime is saturated with muriatic acid, ammonia is set free, —— ee ee e_e ict e ee and the morphia is precipitated. When the solution is greatly concen- — TRANSACTIONS OF THE SECTIONS. 79 trated the precipitation is instantaneous, and is almost equal in volume to half the solution. When, however, the solution is less concen trated, there is at first no precipitation, but as the liquor cools, needles appear, and at a certain point a large mass of precipitate is suddenly formed. The peculiarity of this process is, that it affords a well cry- stallized and fine product of morphia, without requiring the use of alcohol. This is owing to the circumstance that the ammonia is not added in a free state, but is generated in immediate contact with the substance to be acted upon. ‘The morphia is nearly colourless: by dissolving it in muriatic acid, and subjecting the solution to crystal- lization, we obtain muriate of morphia in perfectly white crystals quite pure. The milk of lime, it is to be observed, must not be added to a boiling hot solution of the crude opium, otherwise the precipitate adheres to the sides of the vessel, and does not afterwards re-dissolve perfectly. The liquor containing the morphia should either be coid, or only lukewarm when the milk of lime is added to it. If it is boil- ing hot, it must be added to the milk of lime, and not vice versd. On the Action of Nitrie Acid on the Chlorates, Iodates, and Bromates of Potassa and Soda. By Professor Frep. Penny. The present communication contains the details and results of some experiments undertaken with the view of obtaining additional confirma- tion of the correctness of the author's researches on equivalent num- bers. In this he has been disappointed, as the action is attended by circumstances which render it inapplicable to so delicate a purpose as the determination of equivalent numbers. The results, however, that he has obtained are new, and he considered them of sufficient interest to be worthy the attention of the Section. In order to examine the action of nitric acid upon chlorate of potassa, a known weight of the salt was mixed in a retort with a measured quantity of the acid, and the mixture heated on a sand-bath; as soon as it became warm, chlo- rine and oxygen were evolved in a state of mixture and not of combi- nation, and the chlorate slowly disappeared. The solution was then evaporated to dryness, and the saline residue was found to be a mix- ture of hyperchlorate and nitrate of potassa, in the proportion of three equivalents of the latter to one of the former. The author expresses the reaction that takes place as follows :— 4(K + Cl+ O,) and 3(N + O,) =(K + Cl+ O,) and 3(K + N + Og) and Cl, and O,,;. The action of nitric acid on chlorate of potassa differs, then, from the action of sulphuric acid on the same salt. With nitric acid the salt is decomposed tranquilly, and the chlorine and oxygen are liberated uncombined ; whereas with sulphuric acid these gases are evolved in a state of combination, forming that dangerous explosive compound, chlorous acid. Nitric acid is therefore to be preferred for the prepara- tion of hyperchlorate of potassa, as with it the operation may be con- ducted without those violent detonations that are so apt to occur with sulphuric acid. The action of nitric acid on chlorate of soda is the 80 REPORT—1840. same as upon chlorate of potassa. The chlorine and oxygen set free are in’a state of mixture, and every 4 atoms of chlorate yield 3 of ni- trate and 1 of hyperchlorate. The hyperchlorate of soda is a very soluble salt, and crystallizes in small rhombs. It is readily decomposed by heat, but is unacted upon by hydrochloric acid. It deliquesces by exposure to the air. The action of nitric acid on an iodate is very different from that on a chlorate, and is well illustrated in the case of iodate of potassa. When iodate of potassa is boiled for some time with a large excess of nitric acid, it is decomposed into potassa and iodic acid; the potassa combines with its proportionate quantity of nitric acid, forming the nitrate, and the iodic acid is deposited from the solution in minute, hard, and transparent crystals. If the acid so- lution of nitre, containing the iodic acid, be then evaporated, a re- action takes place; the iodic acid decomposes half of the nitre, sets free its nitric acid, and combines with the potassa, forming the binio- date. This change is completed when the mixture is dry, and if the heat be then withdrawn a definite mixture of biniodate and nitrate is obtained. If the heat be continued, a still further change occurs, the iodic acid expels the whole of the nitric acid, which is evolved as nitrous acid, and oxygen and neutral iodate of potassa remain. By adding a fresh portion of nitric acid to this iodate, the same changes may be produced by a proper regulation of the temperature. By act- ing upon iodate cf soda with nitric acid, Prof. Penny has obtained a biniodate of soda, and by adding a considerable excess of iodic acid to a solution of iodate of soda he has found a teriodate of soda. Both of these salts are anhydrous. The biniodate of potassa contains 1 atom of water. He also finds that crystals of iodate of soda contain differ- ent quantities of water, according to the strength of the solution from which they have deposited. From a hot and strong solution this salt crystallizes in acicular tufts, and these crystals contain 2 atoms of water. Ifthe solution be rather weak, long four-sided prisms are ob- tained, and these contain 6 atoms of water. If a solution of iodate of soda be evaporated spontaneously, large irregular prisms deposit, and these contain 10 atoms of water. They effloresce rapidly by exposure to the air, and lose in this way 8 atoms of water. The action of nitric acid upon bromate of potassa was next examined, and was found to differ remarkably from the actions of this acid on the chlorate and iodate. Neither hyperbromate nor bibromate is produced, but merely nitrate of potassa. ‘The nitric acid sets free the whole of the bromic acid, and this, at the moment-of its liberation, is resolved into its ele- ments, bromine and oxygen. In conclusion, the author remarks that the action of nitric acid on these three classes of salts affords a ready method of distinguishing them from one another. On a New Salt obtained from Iodine and Caustie Soda. By Professor — Frep. Penny. While examining the action of iodine on carbonate of soda a salt was obtained, which crystallized in regular six-sided prisms, and which tract? Sot path iP NF ge ea eT TRANSACTIONS OF THE SECTIONS. 81 gave by analysis sodium, iodine and oxygen, in proportions not corre- sponding to any known compound of these elements. The same salt was also prepared by saturating a solution of caustic soda with iodine, and allowing the solution to evaporate spontaneously. At first this salt was thought to be the same as that described by Mitscherlich in his Elements of Chemistry, and to which he gives the following com- position, NaI + NaO,10, + HO,,; but the analysis gave very dif- ferent results. Professor Penny gives the following characters of this salt. It is white and inodorous, has a sharp saline taste, crystallizes in short six-sided prisms, is soluble in cold and hot water, and is decom- posed by alcohol into iodate of soda and iodide of sodium. It efflo- resces by exposure to the air, and is very readily decomposed by heat ; water in abundance is first evolved, and then oxygen with a trace of iodine. Its solution is perfectly neutral to test papers, gives a pale lemon-yellow precipitate with acetate of lead, yellowish white with nitrate of silver, and a fine bright yellow with pernitrate of mercury. It is not affected by solution of starch, but instantly decomposed with the precipitation of iodine by nitric, sulphuric, acetic and hydrochloric acids. The latter acid in excess converts it wholly into chloride of potassium. He detailed a remarkable circumstance attending the for- mation of this salt from iodine and caustic soda. When the solution is evaporated spontaneously, long prismatic crystals of iodate of soda deposit ; but as the evaporation continues these crystals are re-dissolved, and are replaced by those of the new salt. In one experiment this change was very striking. The solution on Saturday night had de- posited an abundance of fine crystals of iodate of soda; but on Monday all these had disappeared, and a crop of the new salt had crystallized. The prior deposition of iodate of soda generally occurs in the prepara- tion of this salt; and from other experiments of the author it seems necessary that there should be excess of iodide of sodium present in the solution, and that the solution should be strong in order that the salt may form. When this salt is dissolved in water, and the solution eva- porated spontaneously, crystals of iodate of soda deposit, but very few of the new salt will form. The salt may also be procured by pouring a saturating solution of iodide of sodium on crystals of iodate of soda, and setting them aside for some days. The crystals will be dissolved, and be replaced by crystals of the new salt. Professor Penny then gave the details of his analysis of this salt, and the following formula as agreeing best with his result: Na, I, O,. + 38 H O; or regarding it as a compound of iodate and iodide, it may be thus represented: 3NaIl+2Nal0,+ 38HO. According to this view it is the sesqui- iodide of iodate of soda. Additional Observations on the Voltaic Decomposition of Alcohol. By Artuur Connet, Esq. The author showed, a few years ago, that under powerful voltaic agency, the water entering into the constitution of absolute alcohol wasre- solved into its elements, hydrogen being evolved at the negative pole, and 1540. G 82 REPORT— 1840. oxygen going to the positive, where it produces secondary effects of oxi- dation*; and that the galvanic agency was greatly increased by dissolving minute quantities of potash in the alcohol, so small a quantity as ;g2gqth part having a marked effect, by increasing the conducting power of the liquid. As it had been objected that the water of the hydrate of potash employed might contribute to the result, the author has since employed potassium instead of hydrate of potash, with precisely the same effects. It is known, that when potassium is dissolved by alcohol, it is oxidated with evolution of hydrogen, so that in this way we pro- duce the same consequences as if we added anhydrous potash. B adding small quantities of potassium, such as ;35 or 34,, to absolute alcohol (sp. gr. *7918, at 66° F.), and then submitting the liquid to voltaic action, hydrogen was given off at the negative pole; and when the effect ceased, it was renewed by re-charging the battery, and again adding a similar small quantity of potassium ; and the usual secondary effects of oxidation were produced at the positive pole. In instituting a comparison between the quantity of hydrogen thus given off, and that evolved by the same electric current from acidulated water, it is necessary that a powerful current should be employed, and a some- what larger quantity of potassium dissolved; because otherwise, from the inferior conducting power of the liquid, and from a little of the hydrogen entering into the constitution of the secondary products, the quantity of hydrogen evolved from the alcohol is somewhat less than that from the acidulated water; and the comparison is best insti- tuted during the early stages of the action, because the conducting power of the liquid diminishes as the potash gets saturated by the secondary products, and the electric energy declines also. The author still regards these experiments as affording the only direct proof which we yet have of the existence of water, as such, in absolute alcohol. On Resins. By Professor JounstToN. In this paper the author drew attention to the following facts, appa- rently established by a table of analytical results, which he exhibited, and has had printed. Ist. That the resins differ from each other in the quantity of oxygen they contain. 2nd. That in those in which the atoms of oxygen are the same, the hydrogen may vary, and that this is another cause of difference in the properties of the resins. 3rd. That in all the resins hitherto carefully analysed, the number of atoms of carbon is constant. 4th. That the resins, as a natural family, may be represented by a general formula containing two variables. 5th. That the known resins divide themselves into two groups, possessing unlike chemical and physical properties; that of one of these groups colo- phony may be considered as the type, and that it is represented by Cyy Hy +x Oy; that gamboge, or dragon’s blood, may be considered as the type of the other group, which is represented by Cy) Ha, + x O,- * Transactions of the Royal Society of Edinburgh, vol. xiii. voor eS. D ao TRANSACTIONS OF THE SECTIONS. On the Resin of Sarcocolla. By Professor Jounston. The resin of sarcocolla of commerce is separated, by water, into three portions. 1. A gum A, which does not dissolve in water or alcohol, but which is in a great measure washed out by means of the former solvent. 2. A portion B, insoluble in water, but soluble in alcohol, which is of a resinous aspect, and is represented by Cy H5. O,4 The hydrate is C,, H;, O,, + 2 HO when dried at 60°. This portion B is separated (decomposed?) by bases into two or more organic compounds, the alcoholic solution giving, with neutral acetate of lead, a salt containing an organic constituent represented by C4o Hos Oro Ammonia throws down from the mixed solutions a second salt of lead, the constitution of which has not yet been determined. 3. The portion taken up by water from the crude sarcocolla when evaporated to dryness, is separated by alcohol or ether into a solu- ble (C), and an insoluble portion D. 4. The soluble C, dried at 212°, gives discordant results, approach- ing to C4) H;. O,,, but when treated with bases, gives salts containing organic constituents of a different constitution. A neutral acetate of lead throws down a salt represented by Pb O + C,, H,; O;,; and the subsequent addition of the neutral ério acetate, a salt represented by 2 Pb O + Cyo Hyo Oye. 5. The portion D, insoluble in alcohol, but soluble in water, consists of a gum, and of a substance which is precipitated by neutral acetate of lead in curdy flocks. The investigation is still in progress, and the results are to be con- sidered as open to correction. On some Varieties of Peat. By Professor JouNSTON. The author exhibited some varieties of peat from the Moss near Paisley, which he stated were illustrative of a transition from the comparatively fresh vegetable matter to a substance resembling coal, but which he affirmed to be ulmic acid. The author stated that the same substance might be obtained from peat by digesting it in ammo- nia, and afterwards precipitating the brown solution by an acid; while on the other hand, caustic potash extracts another, and which he pro- posed to term humic acid. On a Mode of Detecting Minute Portions of Arsenic. By Dr. CLARK, of Marischal College, Aberdeen. This mode has been applied by the author to the detection of arsenic in commercial specimens of the metals, tin and zinc. Grain tin, made in Cornwall, contains arsenic, which seems to be the occasion of the peculiar smell of the hydrogen evolved from that metal by the action G2 84 . REPORT—1840. of acids. All the specimens of commercial zine that the author had happened to try, were found to contain arsenic. Pure muriatic acid, diluted with distilled acid, is poured upon the metal, and the hydrogen evolved is passed first through a solution of nitrate of lead, and next through a solution of nitrate of silver. Nitrate of lead seems not acted upon by arseniuretted hydrogen, at least when in very small proportion ; but were any sulphur present in the metal, hydrosulphuretted hydrogen would be evolved in conse- quence, and the solution of nitrate of lead would be blackened, which, however, the author did not observe ever to occur. But nitrate of silver seems immediately to be acted upon by most minute portions of arseniu- retted hydrogen. A bluish-black precipitate is formed, which, to judge from a qualitative analysis, appears to be an arseniuret of silver. This bluish-black precipitate may be collected with remarkable facility, from its falling readily from the solution, which it leaves perfectly clear. Heated in a small tube, so that the matter heated comes into contact with the air, the bluish-black precipitate evolves arsenious acid, which, by the liquid tests, may be further satisfactorily recog- nized. Antimony produces a similar precipitate, so that the mere appearance of the precipitate is not enough, without the production and recoguition, by the usual methods, of the arsenious acid. By a few evident modifications, this method may be applied te medico-legal investigations. —————— On the Tests for Sulphurie Acid when thrown on the Person. By R. D. THomsoy, M.D. The object of the author was to discuss the accuracy of the modes of testing sulphuric acid when employed for criminal purposes, and espe- cially when thrown on the person. A case had lately occurred to him in practice, and which was brought before the last session of the Central Criminal Court, which proved that the mode of determining the presence of free acid by mere testing was by no means satisfactory. A woman, in a fit of rage, threw a quantity of oil of vitriol at the face of a cabmaster in the neighbourhood of Euston-square, and before the unfortunate sufferer could wash off the acid only two minutes had ex- pired; yet the consequence was loss of vision intheeye. The author stated, that having attentively considered this case, and made a series of experiments on the eyes of dead animals, he had discovered that this kind of blindness was perfectly curable ; and he had accordingly pro- posed an operation for this purpose ina paper read at the Medical Section. But, besides having his face injured, the hat of the man was discoloured also with the acid. This article of dress was sent to the author, to determine the nature of the agent in this work of destruc- tion. The result of his experiments was, that both the injured and entire hat contained sulphuric acid, as tested by nitrate of barytes ; and a solution of the soluble matter of both states of this article of dress, afforded an acid reaction. It was therefore necessary to adopt rc el GLY AFI E LE ee ee ae = TRANSACTIONS OF TILE SECTIONS. 85 some method which would afford a discriminating test between the free and combined acid. The usual mode, viz. by boiling with carbonate of lead, and concluding, if any insoluble sulphate of lead was formed, that the acid existed in a free state, was found to be totally fallacious, because carbonate of lead decomposes sulphate of soda, contrary to the opinion stated in works of medical jurisprudence. Besides, it was shown that many of the usually so-called neutral sulphates exhibit in reality an acid reaction upon test-paper, as in the instances generally of sulphates of potash, iron, soda, barytes, and also in the case of alum, &e.; and hence the excess of acid attached to these salts, would be apt to act as free acid upon the barytes test. The author, there- fore, concludes that the only demonstrative proof which chemistry affords, is a quantitative analysis. Thus he found the entire hat to contain °356 per cent. of sulphuric acid, probably in the state of alum or copperas, and the injured hat, 1°379 per cent., or in other words, the hat had received by the injury 1-023 per cent. of free sulphuric acid. Here then was afforded clear evidence of the nature of the agent employed to effect the injurious object, which could not have been conclusive if the matter examined had only amounted to a drop or stain. The author directed attention to a point connected with sulphuric acid in a medico-legal point of view, viz. that the oil of vitriol of commerce always contains in this country nitric acid, in addition to various other impurities. Barruel has stated that sulphuric acid is capable of dissolving platinum. The author has not been able to satisfy himself that it dissolves any sensible quantity of gold leaf. Barruel attributes the property which he states it to possess, of dis- solving platinum, to the sulphuric acid, assuming the function of muriatic acid. But the author is not aware of any experiment which would authorize this conclusion. He is rather inclined to attribute the action, if such an occurrence takes place, to the muriatic acid which is present in all the oil of vitriol prepared from sulphur that he has examined. It is given out in sensible quantities, when a solid oil, such as cocoa-nut oil, is acted on by sulphuric acid. This he ascertained several years ago, when examining some Indian oils; and Dr. Kane has since corroborated the fact of the existence of muriatic acid in oil of vitriol. Although the author has not been able to observe the solution of any sensible quantity of gold leaf by the action of oil of vitriol, per se, yet if a few drops of muriatic acid be added, the aciion becomes very powerful; and by the administration of heat, platinum also is dissolved. . These facts, therefore, prove that wherever we have oil of vitriol, we may expect also nitric acid. The author added that he knew of no certain mode of detecting the presence of nitric acid, save by the property which it possessed of dissolving gold and platinum, on the addition of muriatic acid. Pure morphia has no action upon nitric acid; it is the resin which generally accompanies that alkaloid which produces the characteristic yellow colour. But the author found that preparations of opium, in which the resin was excluded, afforded no colour when nitric acid was added. From an examination 86 REPORT— 1840. of numerous cases of poisoning by opium, which had appeared before the Middlesex coroners, he had come to the conclusion that the resin of opium test for nitric acid afforded only an auxiliary method of arriving at the truth, as its characters were frequently verified by other organic substances. On Bleaching Vegetable Wax. By Mr. E. Soxty. In the course of the summer the author made a series of experiments on the best method of bleaching vegetable wax, the green colour of which is very difficult of destruction, and of course a considerable ob- jection to its use in the manufacture of candles. On trying most of the methods usually described as being fitted for the purpose, he found them all more or less objectionable, or inapplicable on a large scale. Some were tedious, requiring a long time for their completion, others expensive, whilst others again were inconvenient, from the difficulty with which the residuum of the materials employed in bleaching were sepa- rable from the bleached wax. The author found that the best effect was produced by chlorine; but in this case it was necessary that the mate- rials used to evolve the gas should be intimately mixed with wax, and then of course the difficulty of separating the residue occurred, and when a stream of chlorine was slowly passed through the wax, the process was very slow and tedious. He subsequently found that strong nitric acid was a very powerful decolorising agent, and it possessed the advantage of leaving no residue which was at all difficult of separation ; the expense of this process was, however, a great objection to its use. The following method was ultimately employed. The wax was melted, a small quan- tity of sulphuric acid was poured in, composed of one part of oil of vitriol to two of water, and then a few crystals of nitrate of soda were stirred in; the whole was then agitated with a wooden stirrer, and kept heated. Nitric acid was thus evolved in considerable quantity and purity from a large surface, and in such a manner that all the acid evolved must necessarily pass through the melted wax. This method answered the purpose very completely; the process was cheap and rapid, and the residuum being merely a little solution of sulphate of soda was very easily removed. When it is desired to employ chlorine in place of nitric acid as the bleaching agent, the same process may be adopted. On a peculiar Class of Voltaic Phenomena. By Mr. SturGEon. The author directed attention to some experiments published by himself in 1830, and to his theory respecting the electro-chemical action of the simplest metals on acid and other solutions. He stated that the fact of iron not precipitating copper from its sulphate and other solutions, as recently observed by Professor Schénbein, was one of the many beautiful phenomena discovered by Keir, and published in the Philosophical Transactions for 1790. ies St Se TRANSACTIONS OF THE SECTIONS. 87 Experiments on Carbonic Acid thrown. off from the Lungs. By Mr. M’GREGOR. These experiments, performed by the author while resident in the Royal Infirmary of Glasgow, were instituted with a view to ascertain whether the quantity of carbonic acid thrown off from the lungs differed in health and disease. The mean per cent. in health he found to be 3°5 per cent., a quantity which very nearly corresponds with that assigned by Dr. Thomson of Glasgow, and Dr. Apjohn of Dublin ; that found by the former being 3°72 as a mean ultimate result, while that of the latter was 3°6. In the eruptive stages of small-pox, measles and scarlet fever, the amount of carbonic acid evolved from the lungs was considerably increased, in the former to from 6 to 8 per cent., and in the two latter to from 4 to 5 per cent. During the aggress and climax of these dis- eases, the per centage of carbonic acid showed the above increase, while in proportion as convalescence established itself, and the skin re-assumed its normal appearance, the per centage of carbonic acid gradually diminished. Ten cases of each of the above specified diseases were so examined. In chronic skin-disease an augmentation was also observed, and in one case of ichthyosis the mean per centage amounted to 7°2 per cent. The scaliness.in that case was universal, and ulti- mately proved fatal. In diabetes mellitus, a disease in which the ali- ment is converted into sugar, and eliminated in the form of urea and sugar, no normal aberration could be detected; the carbon in that case tae eliminated in the form of sugar and urea. Description of a New Instrument for Measuring the Refractive Power of Minute Bodies. By ALEXANDER Bryson, of Edinburgh. While engaged in a series of experiments on the polarising proper- ties of minute crystals, I found that when the microscope was focused to the second surface of a plate of glass, on which some minute ery- stals of Greenockite were placed, the addition of a thin film of Canada balsam spread on the slip of glass, prevented entirely the appearance of the Greenockite, until the body of the microscope was raised two hundredths of an inch above its former position. This property of bodies, with parallel planes, affords a means of ascer- taining the approximate refractive power of minute bodies. On this prin- ciple Mr. Bryson has constructed an extremely simple microscope. On its stage is placed a piece of crown-glass, the refractive power of which has been ascertained, having a few fine lines drawn upon its surface with a diamond point. If a piece of topaz of ;4,th of an inch in thickness is now placed above the lines, it will be found necessary to raise the body of the microscope ‘045 of an inch higher than it was while view- ing the lines before they can be observed after the interposition of the topaz. This difference of focal length then becomes an index to the difference of refractive power between the glass plate and the crystal of topaz. All that we require is to procure the means of ascertaining 88 REPORT— 1840. minute differences of focal length, which is easily accomplished by a scale and vernier, reading to the thousandths of an inch. Thirteen minerals were cut with parallel planes, all exactly 5th of an inch thick; they were placed on the glass micrometer, focused in every experiment at *210 upon the scale; the difference of focus is there- fore the remainder of ‘210 subtracted from the figures cpposite the name of each mineral in the annexed list. Greenockite, Bishopton, Clyde .............. ‘275 (Genanias) (Gesu lon 3 Anes sO boon eg eos +260 ATELY SC POTION EAL ty -)-\ ocho were eiera ete ole siw/e aieieete is "258 Pxehimitesgisislion fon tee ae cies esatete’eters) eke ctelsi crores *258 Topaz Newitollaid’\!. oF raved i ates "255 ERA DEBS UC: Blo eee ae CEE ae ates se i "255 Sul platelets lan yitey ise e512, 5 ots nies 60: <15/a)s180) 912 °255 Beryl, planes perpendicular to axis .......... °255 Opaleconmovoitger emia de - : : “ . 54 810 The males are on piece-work, and are employed ten hours per day ; but when any particular articles are wanted, they are permitted to work twelve hours. None of the females who are not attending classes work more than seven hours in summer and six in winter. Those at- tending classes work three hours each day, and none of them more than two hours at a time. 2 iS 8 Door-mats. - “ 5 - : 5 . 155 8 7 4 9 woomnNouumDace TRANSACTIONS OF THE SECTIONS. 173 A Comparative View of the State of Crime in London, Dublin, and Glasgow. By Captain Mituer. 7 aan 7 s | 6 $6] 6 Sy: = a4. Oo | oR + ao 3 BSO8 | 20 aos (a3 2 | 54 23 |e 2 aes (ogee | 28 |S5 ws xf 5 Ss8a|8ee\|ae sa Cities. S a ans | ets cS o ro Sr E as So |S:4 Pa) S Ems) Oss] 29 \s' = ov | SE am a g Seh|/.8 | Be [Ss $ os | ee a |é8 Stiles the City ae 1839] 175,900] 7,687 |1 in 223| 223 | 784 On the comparative Vital Statistics of Edinburgh and Glasgow. By Mr. Watt. The proportion of marriages to the population in Edinburgh and Leith is as 1 to 144°449, or 0°692 per cent. In Glasgow the propor- tion is as 1 to 124°942, or 0°800 per cent. The number of deaths under twenty years of age in Edinburgh, in 1839, was 43-060 per cent. of the whole number of deaths; while in Glasgow the proportion was 62-312 per cent. In Edinburgh the proportion of deaths to the popu- lation was as 1 to 45°435, or 2°200 per cent.; in Glasgow the propor- tion was as 1 to 36°146, or more than 2°766 per cent. The deaths of children under five years of age are, in Edinburgh, | to 141°598 of the population; in Glasgow they amount to 1 in 72°014: in Edin- burgh they are less than one-third of the whole number of deaths, in Glasgow more than one-half. From the imperfect state in which the registers of births are kept in Scotland, Mr. Watt declared that no re- liance could be placed on the existing data of comparison; and the same remark, though in a less degree, extends to the registration of the causes of death, as data for the statistics of disease. On the Vital Statistics of Glasgow. By Dr. Cowan. Dr. Cowan exhibited a variety of tables, illustrative of the Meteoro- logy and Statistics of Glasgow. He also exhibited a map of Glasgow, coloured, to show the state of the districts in relation to fever. From the table of marriages, it appeared that their proportion to the popula- tion, though always high, is fluctuating, depending on the state of trade and the prices of provisions. The extremes are to be found in 1825, remarkable for prosperity, when they amounted to 1] in 83°98 ; and in 174 REPORT—1840. 1837, a year of destitution, when they fell to 1 in 120°76. From the table of births, it appeared that the ratio of males to females was as 22 to 20, a proportion much above that of any country in Europe. In 1831 the proportion of still-born was 1 in 14°49, a remarkable fact, as the ordinary average is about 1 in 20. The tables of deaths gave the mean annual mortality in Glasgow from 1822 to 1830, both inclusive, as 1 in 38°275; and from 1831 to 1839 as 1 in 31°896. The deaths under five years of age, for the nine years ending in 1830, were 42°91 per cent.; and for the same period ending in 1839, they were 43°32 per cent. It also appeared that the rate of mortality generally in Glasgow had increased during the last nine years, which was attributed to the increase of population beyond the suitable means of accom- modation, the fluctuations of trade, &c. The number of deaths from smallpox was very great, amounting to 406 in the year 1839. The prevalence of epidemic disease was illustrated by several tables, from which it appeared that their advance had been slow, unless when ex- treme destitution prevailed. On the Population, Trade and Commerce of the City of Glasgow. By Dr. CLELAND. The following are extracts :— Increase of the Population, Revenue, &c. of Glasgow. “ Population.—In 1801 the population, according to the Government census, was 83,769, and in 1840, according to the three subsequent decennial returns, including the nine years from 1831 to 1840, the population amounted to 271,656, showing an increase in 39 years of 187,887 souls—a rate of increase, it is believed, unprecedented in this country. “ River Clyde—In 1800 the revenue of the River Clyde was 33191. 16s. 6d. In 1839 it amounted to 43,2872. 16s. 10d., being an increase during 39 years of 39,968/. Os. 9d. “ Shipping in Glasgow.—In 1651, a Committee of the Scotch Parlia- ment appointed Commissioner Tucker to report on the Revenue of the Excise and Customs in Scotland, who stated that there were 12 vessels belonging to Glasgow; that the aggregate tonnage amounted to 957 tons. In 1840 the house of Messrs. Pollock, Gilmour and Co., of this city, who are engaged chiefly in the North American timber trade, are owners of 21 ships, register 12,005 tons, navigated by 502 seamen. The house has eight different establishments that ship annually up- wards of six millions cubic feet of timber, to cut and collect which, and to prepare it for shipment, requires upwards of fifteen thousand men, and six hundred horses and oxen in constant employment. “ Steam Vessels——On the Ist of January 1812, there was only one steam vessel in Europe, the Comet of Glasgow, of 30 tons burthen, with an engine of three-horse power. Now almost every river teems with them. It appears from the Parliamentary Steam Vessel Inquiry, that on 11th February 1839, there were 766 steamers connected with TRANSACTIONS OF THE SECTIONS. 175 the United Kingdom. Including the four North American mail steam- packets, the steam tonnage of Glasgow, in 1840, may be estimated at 13,491 tons. “ Custom House.—In 1812, the custom duties collected in Glasgow amounted to 3124/. 2s. 45d.; and in 1839 to 468,974d. 12s. 2d., being an increase during 27 years of 465,850/. 9s. 114d. “ Post Office—tIn 1810, the revenue of the Glasgow Post-oftice amounted to 27,5981. Gs.; and in 1839 to 47,5271. 7s. 7d., being an in- crease during 29 years of 19,929/. 1s. 7d. “ Supply of Water.—Prior to 1806, the city, comprehending the ancient royalty alone, was supplied by about 45 public and private wells. As some of these were frequently dry, and others contained water of a bad quality, it may be near the truth to take the average supply of each well at 120 gallons of useful water, thus making the aggregate supply of 5400 gallons per day. The Glasgow and Crans- tonhill Water Companies, now incorporated by Act of Parliament, produced, in 1840, 8,218,000 imperial gallons. The revenue of these two companies, for 1836, amounted to 25,3027. 13s. 9d., and they laid out in conveying water from the Clyde to the city the sum of 349,8082.” The population in 1831, when the last census was taken, consisted of 163,600 Scotch, 35,544 Irish, 2919 English, and 353 foreigners. The following is a description of the householders :— ‘* Married men, 30,032; Widowers, 1790; Bachelors, 1437; Male Householders, 33,259; Widows, 6824; Spinsters, 1882; Female Householders, 8706; Total Families, 41,965. “ The births, including 471 still-born, being 6868, and the population 202,426, there is one birth for every 29°47 persons. “ The marriages being 1919, there is one marriage for 105*48 persons. “ The burials being 5185, there is one burial for 39-04 persons. ** The number of families being 41,965, there are 4°82 persons to each family. “ The births being 6868, and the number of marriages 1919, there are 3°57 births to each marriage.” On the State of Crime within the Suburban Districts of Glasgow. By Mr. RutHERcuen. The supposed population of Calton, in September 1840, was 28,210. The police force consists of 1 superintendent, 6 serjeants, 14 watchmen, and three lamp-lighters, who also act in the capacity of scavengers, Expenses of the establishment for the year ending September 1839, including salaries, wages, lighting, cleaning, Bridewell, and other charges, 1324/. 17s. 114d. Extent of Crime.—During the year ending 30th September 1839, 2601 persons were charged with crimes, offences, and with contra- vention of police regulations. Of this number 1799 were found guilty, and sentenced—208 to confinements of various durations 176 REPORT—1840. in the Burgh Bridewell, and 1591 to pay fines, which amounted to 2071. 2s. 8d.; the remainder were disposed of as follows :—56 were transferred to the Sheriff, 63 to the Justices, 5 to the Glasgow police, 1 to the Lunatic Asylum, 5 to the House of Refuge, 430 were re- proved and admonished, and 242 were dismissed. The criminal popu- lation is less by one-half than it was in 1835-6 ; and although in 1839 there were 2601 charged, and 1799 convicted, it is proper to mention that the same person has been charged and convicted as often as three times with petty thefts, and with other crimes and offences éwenty times in the course of the year ; and it is not in one, but in many cases, that this has occurred. House of Refuge.—The establishing of this Institution has had a beneficial effect in the repression of crime, by withdrawing from the streets of the city and suburbs several hundreds of destitute boys, who lived almost by thieving alone ; and it is not an over-estimate to say, that 250 of them stole property averaging Ls. each per day when loose upon society. Pawnbrokers.—There are two licensed within the burgh. Brokers.——In 1835 there were 120 brokers in Calton ; in 1839 they were reduced to 88, and the following is their classification :-— Pieaee gs TONE WESANS face cae pe ed's ap 8 Ye acer ee ce tae 4 Parsee PORES so, So. sts ws ee tee eee 16 Dealers in old weaving utensils.................. 4 Dealers who buy all their goods at public sales...... 4 Wealers indie Clothes en oS). sf oe ss tae e tee eee 4 Bundle-brokers, or “Wee Pawns”.........+...+2. 56 Publicans.—There are at present 119 licensed publicans within the police bounds ; and during the year ending September 1839, 38 cases were brought before the magistrates of disorderly houses. Lodging Houses—are generally of an exceedingly wretched de- scription, but the Police Act gives powers for the regulating of those houses. Health.—The state of health is anything but satisfactory. Fevers, pulmonary complaints, rheumatism, and influenza prevail. On the State of Crime in the Suburban Burgh of Anderston. By Mr. Fixvvater. From the tables produced, it appeared that the cases brought before the magistrates of the burgh of Anderston were of the most trivial kind. Last year there was not one charge of robbery ; out of 101 cases of theft, only one was sent to the sheriff, while 62 petty cases were re- mitted to the justices. The number of cases brought before the police court for the year ending 21st September 1840, were 1205, and the num- ber of persons 1900, among which there were about 300 for dirty closes alone, besides a corresponding number for exposing articles outside of shops, encumbering streets, and other minor contraventions of the Police Act, and about a fourth of the remainder are offenders from the TRANSACTIONS OF THE SECTIONS. 177 city. The cases were disposed of as follows :—879 were fined in vari- ous sums, amounting to 1902. ; 64 were confined for short periods in the police cells ; 1 sent to the sheriff; 75 to the justices; 1 to another town; | escaped; 2 policemen discharged; 4 reproved, and 177 dis- missed. Total, 1205. On the State of Crime in the District of Gorbals. By Mr. Ricuarpson. Gorbals. Glasgow. MMT 6 2's a ws oh Big 2 ake ES egies RT 65,000 175,060 Average assessment for each inhabitant ...... 1s. 13d. 2s. 24d. Number of offenders brought before magistrates 4,009 7,687 Proportion to the population................ 1 in 162 1 in 22 Expense to the public for each offender ...... 9s. 1. 5s. Number of persons admonished.............. 903 1,879 Number convicted .........-02---- 2+ cecees 3,106 6,570 Reported value of property stolen............ 5001. 7,6531. Amount of property recovered .............. 3001. 1,2601. Number of superior officers ................ 3 12 aaaes SORRMNEPY OMICOPS ie. os ite f/m lolarein *E 8 59 Se tatee WALTER OTE dss a'a cic es aie tie an nela 29 149 pe CRIMINAL OHICEIS 20 OL Ste ae ha ws 1 6 Cost of the above department of police........ 1,8331. 9,568/. On the State of Education in the Borough of Kingston-upon-Hull. By the MANCHESTER STATISTICAL SoOcIETY. The present report contains the result of an inquiry carried on in the months of March, April, May, and June, 1839. The whole of the facts were collected by the same agent to whom the previous investiga- tions of the Society of a similar kind had been intrusted, and of whose perseverance and accuracy the Society have had ample experience. The object was twofold : first, to throw light upon the physical, moral, and religious condition of the great body of the inhabitants ; and secondly, to ascertain the state of education, both in its results, as apparent in the acquirements of the people, and with respect to the use which was made of the existing means of education for the younger portion of the community. In regard to the Sunday schools, very complete information was obtained throughout the whole borough of Hull, containing a population of at least 52,000 inhabitants. The township of Kingston-upon-Hull, containing a population of 37,885, ‘was examined from house to house ; it presents a remarkable contrast with the large towns visited in Lancashire in the character of the dwellings of the working classes. It was found that of 8757 dwellings visited, only 15 were cellars, and their inmates amounted altogether to 44. persons. In Liverpool nearly one-fifth, and in Manchester and Salford about one-tenth of the working classes were found to be living in cellars, while in Hull there are only 15 for every 10,000. The 1840. N 178 REPORT—1840. system of living in lodgings is also less extensive in Hull, and there are only 6239 heads of families occupying houses, as distinguished from chambers, out of the total number of 8757 heads of families ; whereas in a corresponding table for the township of Pendleton, near Man- chester, about nine-tenths of the heads of families are recorded as occupying houses. Under 10 years of age, only 43 children were found at work in Hull, while in Pendleton, with one quarter of the population, there were 37. Between the ages of 10 and 15 there were twice as many at work in Pendleton in proportion to the population, and between 15 and 21 years of age the proportion was also somewhat larger. One-third of the adults whose occupation was recorded in Pendleton were females, as also were about nine-twentieths of the minors at work; while in Hull little more than one-third of the minors at work were females, and not quite one-fourth of the adults. The proportion of persons under 21 years of age is smaller in Hull than in Pendleton, and there is also less employment for children and females in Hull. The relative proportion of the sexes does not differ mate- rially. But the most remarkable contrast between Hull and the Lan- cashire towns appears in the country from which the people spring. In Hull above 95 per cent. of the heads of families were English, only 2 per cent. Irish, and 13 per cent. Scotch ; and taking the whole adult population, the proportions are— eta his Salas, ajere aie ore. t a dasarighs 95°08 per cent. Bey 2 zeal- yin i cayengie ehekere-ciala ‘sie & bane 2:24 — oo | CNN I I a SNR er oe! 6 ae BaOreignetss ai A in. digits cor, 98 vais ase 84 — Welsh it s:55 tba OPP Rie e ees See wos aie 48 — 100°00 In Liverpool and Manchester the Irish form no inconsiderable portion of the whole working class. In Manchester more than one-sixth of the heads of families amongst the labouring population were Irish ; and taking Manchester and Salford together, the Irish constitute one- sixth, the Welsh one-thirtieth, and the Scotch one-fiftieth of the whole, while in Liverpool the proportion of Welsh is much greater than in Manchester. Among the day schools of Hull the agent remarked the existence of a large number of charity schools. There were two proprietary schools, one chiefly supported by churchmen, the other by dissenters. The poor-house schools appeared both clean and orderly, and were conducted on a system somewhat assimilating to that of Dr. Bell. The infant schools, of which there were several, were of com- paratively recent establishment. So far as the opportunity was afforded for observing the condition and management of the dame schools, they appeared to be equal to the same class of schools in Birmingham, and superior to those of Liverpool and Manchester. They were generally tolerably clean, and not so confined as in the large manufacturing towns. The following statement of the proportion of day scholars to the total population has been prepared, showing, by comparison with the numbers in other districts previously examined, that the result for TRANSACTIONS OF THE SECTIONS. 179 Hull closely approximates to York and Rutlandshire, which have been the most favourable examples hitherto brought to light by the inquiries of the Society. The ascertained cases, in a population of 32,500, are here taken, and they furnish a proportion of 16:45 per cent. of the total population attending day or evening schools. 3°33 per cent. were under 5 or above 15 years of age; leaving, therefore, 13°12 per cent. as the proportion of the total population, being children be- tween the ages of 5 and 15, then in attendance at day schools. In Hull it was ascertained that the proportion of individuals of this age was 21 per cent. of the entire population ; it is therefore proved that 7°88 per cent., or rather more than one-third of the children between 5 and 15, were not in attendance at the day schools. The actual number counted, corresponding with this proportion, was 2573, of whom 306 were between the ages of 5 and 10, and 1566 between 10 and 15. 58 were under instruction at home. 1872 had been at day schools at some period. 238 were, or had been, at Sunday school only. 405 had never been at any school, and appeared not to have been instructed at home. 2573 The following table, drawn up from earlier reports of the Society, in York, Rutlandshire, Liverpool, and Manchester, shows that the pro- portion of children moé in attendance at school, is smaller in Hull and York than in Liverpool and Manchester :— Proportion of Children attending Day and Evening Schools, as compared with the total Population. York Rutlandshire| Liverpool Manchester 1836 1838 1835 and 6, | Iestand 5” : é fs 5 and 6. d 5. Per-centage of children attending. | poputation Population | Population Population estimated, | estimated, estimated, estimated, 000. 230,000. 255,000. Day schools supported exclu- } ; , i sively by the scholars......... “a aon ont ne Ditto supported or assisted by - ‘ : e EM PMOIC) es teccvacse sess daaiee as oo e387 ao Evening schools ...........0.0ese0ee 0-15 0:37 0-24 0°78 Total......... 16-96 15:19 12-81 10-46 —-—_— Proportion to the total popula- tion of day and evening scho- : 2, : ; lars under 5 and above 15 se a a fe Years Of AGE.......cecsceeseeeees Proportion to the total popula- tion of day and evening scho- y r 5 . lars between 5 and 15 years amie ae nrGe ae OED his ass say calslth Pasens suits Proportion of children between 5 and 15 years of age estimat- ed not to be in attendance at day or evening schools, about Oto ie on ts n@Q2 180 REPORT—1840, The number of adults who can both read and write and cipher, amounts to nearly two-thirds of the ascertained cases, of whom at least nine-tenths can read; while at Pendleton, in Lancashire, only about one-third of the ascertained cases amongst the adults were able to read, write and cipher, though nearly the same proportion as in Hull were able to read only. In Pendleton, 405 adults out of 4855 ascertained cases had never attended a day school; but some few of these had acquired the power of reading, and even of writing. In Hull, 417 only, out of 14,526 ascertained cases, had never been at a day school, and none of them had learned even to read. Those who could read were in the proportion of fifty-five in Pendleton to sixty in Hull; those who could write were twenty-four in Pendleton to thirty in Hull; and those who could cipher were twelve in Pendleton to twenty-two in Hull. An attempt was made in Hull to ascertain the age at which the children had been taken away from school, and the information was obtained in about three-fifths of the cases. ‘The result obtained on this subject shows, that out of about 2798 children, only 131 had remained at school after reaching the age of 13. 1108 left at 12 and 13 years of age. 964 ,, 10 and 11 = 595 left before 10; about one-half of whom had been removed before they were 9. Hardly any of those who had left school before the age of nine had acquired any knowledge of figures or of writing; and for ninety of them who were able to read, there were as many more who did it very badly, and above 120 who could not read at all. Out of 5250 children who were at school at the date of this inquiry, 305 cases occurred in which no satisfactory account could be obtained as to the regularity of attendance ; and the attendance in 997 cases was admitted to be very irregular ; so that in 3948 cases alone can it fairly be assumed that the children were deriving from their attendance the whole of the benefit, little or great, which the schools were capable of affording. In the case of the children who had left school, the result was still more un- favourable; out of 4097 ascertained cases, only 2426 had attended re- gularly, and 1671 irregularly ; 628 cases occurred in which no satis- factory information on this point could be obtained. Taking the whole of the minors who either had been, or were, at the time of the inquiry, at school, 6374 were stated to have attended with regularity, and 2668 irregularly; and in 943 cases no information on the subject could be obtained. The number of children who could read with ease corre- sponds very nearly with the number of those who had been regular in their attendance at school. The former amounted to 6166, the latter to 6374, and the number of those who could write and cipher was much smaller—the number of those who could write amounted to 3038, and the number of those who could cipher to 2207. It may with tolerable certainty be inferred from the Hull tables, that there is the greatest regularity of attendance between the ages of eight and eleven. Amongst the number of parents whose children were of an age to TRANSACTIONS OF THE SECTIONS. 181 be at school, but who were not attending any, 133 gave the following as reasons for their non-attendance : 35 Poverty. 32 Irregularity of their employment. 19 Want of decent clothing. 6 The children living with their parents in boats on the river. 13 Ill health of parents. 15 Death of the father. 2 Desertion of the father. 11 Largeness of the family. 133 Of the 4735 minors who, at the date of this inquiry, had completed their education, such as it is, 823 were unable to read a whole sen- tence; 1870 were unable to write; and 2282 unable to cipher. In the same class of children, those who had been irregular attendants at school amounted to 1671. In a classification of the answers given by the heads of families, as to their religious denomination, no less than eighteen different Christian sects were enumerated ; and ten of these support their separate Sunday school. Proportion per cent. of the Sunday Scholars to the total Population. Manches-| Birming-| Liver- Hull, | Bury, | ter & Sal. Hptlans: Leeds, York, rie 8 pa 1839*, | 1835*. ford 1838*, 1836}. 1836*. | jg3gt. |1835-6*. 1834.5*, Church of England) 6:11) 7-67) 5:11 | 11:60 5:03 6:10 2:54) 2°75 Roman Catholic...| O31) 0:78} 1:76 | —— 8:88 betioe Bey Dissenters ......... 6°66} 12:67| 9-97 4:38 5-91 6°59) 3:63 0-18) 0:30 Total...| 13-08} 21-12} 16°84 15-98 | 1391 | 12-01, 9-31] 6-68 Proportion per cent. of the Sects to the total number of Sunday Scholars. (Church of England| 46:75) 36:33) 30:33 | 72:56 36:13 50°79) 27-24) 41:11 {Roman Catholic ...} 2°35} o: | 10-46 | —— 63-87 aus 2:02) 4:56 ‘Dissenters ......... 50°90) 60:0) 59-21 | 27-44 49-21; 70:74) 54:33 } i Total...| 100-00) 100-0 | 100-00 100-00 100:00 | 100-00} 100-00; 100-00 On Pawnbroking in Ireland, and on the beneficial results which had followed from the establishment of a Mont de Piété, in connexion with a Loan Fund, at Tanderagee. By Mr. Porter. “In order to ascertain as nearly as possible the amount of business _ which is done throughout Ireland, I consider that one whole county, that of Armagh, in which I reside—one large trading town, such as Belfast—and the metropolis of Ireland, would furnish data on which to calculate, if necessary, the pawnbroking business of the whole king- dom. I therefore deposited at every pawnbroker’s in these places an * Inquiries conducted by the Manchester Statistical Society. + Inquiry conducted by the Town Council of Leeds. + Inquiry conducted by a Committee in Birmingham. 182 REPORT—1840, article of clothing, and received duplicates or tickets, each bearing a number on it, showing the order in which articles are received and registered. In seven days after I deposited another article of dress at each pawnbroker’s as before, and received in like manner duplicates or tickets, and in a few cases, where there was some doubt as to the numbers written on the tickets, which are not always very legible, I deposited a third article. The amount of money lent is calculated, on an average, at 3s. on each article, except in Dublin, and there it is found to be about 4s.” Mr. Porter then read the following table :— age 82 E z Profit after Print- SE/ Se. | ees 2S a ing Duplicates, a sS6| 58 | 8 s fe S28 and deducting | City or Town. |E.5|) 256 | 238 SEs 6 per cent. 3 5&6 E as | 22° Ea, | for Capital, and . GSl Ae ges B.A 6 per cent. for a = Shen | 4 Stock. Armagh ......... 4 97,980|£14,697 | £408 5 0) £1,170 3 10 10,518 Lurgan... 3| 43440| 6516] 181 00| 516 3 73| 2,842 Newry, part of...| 2| 40,680} 6,102} 169100) 483 7 13 |4 Scenext Tanderagee ...... 1 15,540} 2,331 64 15 0 184 13 83 1,559 Portadown ...... 1 14,940) 2,241 62 50 177 10 =93 1,591 Markethill ...... 1 9,660} 1,449 40 50 11415 63 1,043 Total in the C. spueyey } 12 | 222,240/£33,336 | £926 0 0) £2,646 14 2 Newry, whole of| 7 | 120,000/£18,000 | £500 0 0) £1,425 15 6 13,135 Belfast cys00c6e 0 35 | 737,280) 110,592 | 3,072 00} 8,760 19 12 | 67,388 Dublin ............ 42 |8,820,200] 764,040 | 15,917 10 0} 56,107 11 3 | 265,316 The poor of the county of Armagh, therefore, pay for duplicates nearly one thousand pounds annually, the poor of Newry five hun- dred pounds, the poor of Belfast above three thousand pounds, and those of Dublin near sixteen thousand pounds. The paupers’ pence charged by the pawnbrokers, in the county of Armagh, in twelve months, exceeded the county grants to dispensaries by the sum of 1321. 17s. 6d. Paupers’ pence being: ......si.ssscc00s5...8920 0 @ eel! fee County grants to dispensaries............ 793 2 6 132 17 6 And the estimated profits of the pawnbrokers within the county of Armagh, after paying for the printed tickets, and deducting six per cent. for interest on their capital, exceed the whole of the Grand Jury presentments for charitable purposes by 2600. 10s. 4d. PRM PITA ERY chess dct «satigwdeeene esse saesecedse £2,646 14 2 Grand Jury presentments, viz. Warts TMapensanies:. |..i.. 0.0008 e c6793 2s 6 County AMBrHIADG .5...5)..c0002.0-0 B98 B14 District Lunatic Asylum, sinners paneamts 999 18s £2,386 3 10——260 10 4 TRANSACTIONS OF THE SECTIONS. 183 “‘ Having succeeded in proving to the gentry, to the clergy of all persuasions, and to the merchants of the town of Tanderagee, in which I reside, that the Mont de Piété system of pawnbroking would present a mitigation of evil, they co-operated with me in the establishment of an institution, embracing a charitable pawn-office, a loan-fund, and a bank for savings, all under one administration, managed by the same board of directors, with whom I have the pleasure of acting as one of the honorary secretaries.” The following is an abstract of the result of the operations of the Tanderagee Mont de Piété :— Won 3 ae FEET Perse Amount recei-|Interest received a 22 3 E a on Panne ved on Pawns on Pawns Z Ay = 7, Ay S ; released. released. 1839. Vedas EN Ginn ghd ues wad: For nine months, Jan. to Sept. | 12,312] 8,521) 1,500 6 0} 1,023 9 8) 76 0 23 For three months, Oct.to Dec. | 2,900) 3,020} 422 8 4) 395 4 0} 3415 33 —————————— Total for twelve months...| 15,212} 11,541} 1,922 14 4) 1,418 13 8} 11015 6 1840. For nine months, less nel 6,523| 6,698} 864 911] 981 5 5/ 10411 0 weeks, tothe present period Increase of inter- est, the Releases being greater Decrease on the nine months of| than the Pawns. 1840, less two weeks, compar- ed with nine months of 1839] 5,789] 1,823) 635 16 1 42 4 3) 2810 92 In nine months of 1839, 11 out of 16 articles were released, and 3791 articles remained in store, over and above the number of articles re- leased ; and in 1840, up to the present period, 175 articles were re- leased, more than the whole number pawned. LOAN FUND DEPARTMENT. H@ | 4 Interest. = 8 a4 Weekly and 24 | € 5 | instalments. | Fines Aw |< received. 1839. £ & da) & s.d. For nine months, Jan. to Sept....| 3,745 |15,286| 15,107 11 11/608 2 5 Forthree months, Oct. to Dec....| 1,011} 4,141] 4,247 11 2/178 11 2 Total for twelve months...... 4,756 |19,427| 19,355 3 1/786 13 7 1840. Nine months, less two weeks to present Pes alae Sete 8 a03 6 7a1 18 Decrease onthe 9 months, less 2weeks, of 1840, compared +| 1,765] 7,186] 6,804 5 4/316 14 1 with 9 months of 1839 ... 184 REPORT—1840. SAVINGS’ FUND DEPARTMENT. Lodged. Withdrawn. Savings in nine months of 1838 ............ lets Ma £408 — in nine months of 1839 ............ 994 ......cccceeeee 594 — in twelve months of 1839 ......... 1306 OE 4S Mr. Porter gave an account of a Mont de Piété since established at Portadown ; and mentioned that he had been last year successful in establishing one in Belfast. Mr. Porter then presented estimates of the extent of business carried on by the licensed and unlicensed pawn- brokers of Glasgow: viz. by the licensed pawnbrokers, loans, 149,674. ; and by the unlicensed pawnbrokers, above half a million of money, the latter sum at an interest of 433/. 6s. 8d. per cent. Mr. Bryce of Belfast, stated that the Ulster Statistical Society had made such progress in their inquiries into the state of education and the condition of the linen trade in the North of Ireland, that they would be able to present the results in a complete form at the next meeting of the Association. On the Bill Circulation of Great Britain By Mr. Leatuam. Having, through Lord Morpeth, obtained a return of the number of stamps issued from 1835 to 1839 inclusive, Mr. Leatham based his calculations on the supposition that each bill was circulated for half the sum which the stamps would cover, which was considerably under the amount. From the experience of his own bank, compared with that of the principal discount offices in London, he had found that the average date of bills, including foreign and inland, was three months. He then took the whole stamps for a year, and divided them by four, which gave the amount circulating at one time. By a similar induc- tion, he had estimated foreign bills at one-sixth of the English, though the proportion was rather greater; and he had taken the same average for Irish bills in the years where no official returns had been made. He then exhibited the following statement relating to the bill circulation of Great Britain and Ireland, during the years under-mentioned :— 1815. 1824. 1825. 1826-7. dots £ £ £ £ Bill Stamps for Great eae 477,493,100|232,429,800 260,379 ,400|207,347,400 creating the sum.........0.+0- Estimated Irish Bills ... 79,582,183) 38,788,300) 43,396,566) 34,557,833 BOrelenstls Derccwssencdscones:sass0> 92,845,880) 45,194,683) 50,629,327| 40,317,072 Total ........-..../649,921,163/316,362,783|354,405,293 282,222,305 Average amount in cireulation } 162,480,290 79,090,695| 88,601,323, 70,555,576 At ONE AME ses seoetasavenereces'e TRANSACTIONS OF THE SECTIONS. 185 The following is a similar return for the last five years :— 1835. 1836. 1837. 1838. 1839. £ £ £ £ £ British Bills ............ 294,775, 269|355,288,900|333,268,600/341,947,400'394,203,000 Trish Bills ......0..00:..- 51,109,061] 59,155,607| 54,179,165) 54,359,464) 55,615,722 Estimated amount of 5 Foreign Bills .... 57,914,721) 69,420,406) 65,012,080) 66,500,577) 75,479,120 Billscreated by Bank- ’ ers compounting 1,604,000} 2,078,560} 2,624,600) 2,696,600} 3,196,000 for Stamps......... otal... 405,403,051|485,943,473|455,084,445|465,504,041/528,493,842 circulation at one +|101,350,762/121,485,868/113,771,111/116,376,010/132,123,460 REC yeticvesiwessessas Average amount sf On the State of Education and Crime in England and Wales. By Mr. Josep BEnTLey. The author exhibited, in a tabular form, the proportion of persons to one school, one bookseller, one public library, one Mechanics’ Institute, and one ale-house, in the several counties of England, explaining that he had collected these data while engaged in the compilation of Pigot’s Directory. He had taken the criminal statistics from the parliament- ary return of committals, and the amount of population from the last decennial census. He entered into a very minute comparison between the town of Dudley and the city of Worcester, from whence he in- ferred that education was demonstrably a restraint on crime. —_——— Dr. W. Cooke Taylor read an abstract of a paper communicated by Mr. Saxe Bannister, ‘On the Population of certain parts of Africa.’ The object was to show, that the function of vitality was much higher in the American settlement of Liberia than in Sierra Leone and the Anglo-African colonies ; and also that the natives more readily came to the Americans than to the British. On the Application of Statistics to Moral and Gconomie Science. By Dr. CHALMERS. On the Pauperism of Glasgow. By Dr. CHALMERS. Illustrations of the Practical Operations of the Scottish System of the Management of the Poor. By Dr. Avtson. 186 REPORT—1840. The discourses of Dr. Chalmers and Dr. Alison contained frequent references to statistical data, but the enumeration of these would be of little service without a full statement of the arguments they were in- tended to support. On the excess of Population, and on Emigration as a Remedy for it, in the Highlands of Scotland. By Dr. Aucorn. On the Population of Scotland. By Mr. Witson. On the Libraries of Germany. By Professor ADRIAN. On the Parish of Dunfermline. By the Rev. P. CHALMERS. MECHANICAL SCIENCE. On the Temperature of most effective condensation in Steam Vessels. By J. Scort RussE tt. Much has been said regarding the perfection of the vacuum formed in the condenser of a steam-engine, especially a marine engine. It is a fact of great importance, and it is the result of theory, established on incontrovertible truth, and confirmed by experiment and by practice, that a vacuum may be too good, and become a loss instead of a gain. The truth is simply this, and should be known to every engineer: Jf the barometer stand at 294 inches, the standard of this country, the vacuum in the condenser is TOO GOOD éf it raise in the barometer more than 28 inches of mercury. The following is a simple proof of this doctrine, divested as far as possible of a technical form, and put in the shape of an inquiry into the best state of a condenser :— Let ¢ = the caloric of water of 1°; c = the constituent calorie of water in the state of steam ; e =the total force of steam in the boiler, in inches of mer- cury; and x = the elastic force of steam at the temperature of best con- densation, which we seek to discover. Then, from the law which connects the elastic force of steam with TRANSACTIONS OF THE SECTIONS. 187 temperature, it follows that, in case of maximum effect, or the temper- ature of best condensation, é =~, that 1s an. ce c Now ¢ is 1000; and if the steam in the boiler be at 5 lbs. above the atmosphere, or if e = 40 inches of mercury, and ¢ = 1, 40 = ——_ = 0°04. tai cea Again, if the steam be at 73 Ibs. = 45 inches, 45 = — = 0:045. SSD Ts laa Again, if the steam be at 10 Ibs. = 50 inches, 50 = —— = 0°05. “= 7000 Hence we find, that the best elasticity or temperature in the con- denser depends on the elastic force of the steam in the boiler. With steam of 5 lbs. in the boiler, the elasticity of maximum effect in the condenser is 93° Fahr., and the best vacuum on the barometer is 28. With steam of 7% lbs. in the boiler, the elasticity of maximum effect in the condenser is 95°, and the best vacuum on the barometer is 27°8. With steam of 10 lbs. in the boiler, the elasticity of maximum effect in the condenser is 97°, and the best vacuum on the barometer is 27°6. In like manner it would be found, that with steam of 50 Ibs. in the boiler, worked expansively, as in Cornwall, the best vacuum in the condenser would be about 26° on the barometer. It is hoped, therefore, that engineers will not in future distress them- selves at finding the vacuum of their condenser much less perfect than the vacuum of others who have obtained 30 and 30% inches at so great a loss of fuel and power. To obtain a vacuum of 294, with the weather glass at 29°75, and steam at 73 Ibs., would be to sacrifice four horses’ power out of every hundred. Ina day when the barometer is as low as 284 inches, the vacuum in the condenser would indicate 26°8. In speaking of the vacuum in the condenser, it would save much ambi- guity to indicate the elasticity merely of the steam in the condenser ; thus, if the barometer stand without at 292, and the barometer of the condenser at 28, it might be stated that the steam in the condenser stands at 14, being the point of the maximum effect. The indication would convey at all times more precise information. Mr. Russell stated that the President had just put into his hands a communication in French on this subject from M. Barnes. Instead of a jet playing inside the condenser, M. Barnes allows it to rush in sud- denly, and then stops it by a slide-valve. 188 REPORT—1840. Additional Notice concerning the most xconomical and Effective Pro- portion of Engine Power to the Tonnage of the Hull in_ Steam Vessels, and more especially in those designed for long Voyages. By J. Scorr RussE.t. After describing the unsettled state of opinion and practices on this subject, Mr. Russell entered into a general examination of the subject, from which the following are extracts :— ‘We may now proceed to investigate the question of best proportion, or the point where the attainment of high speed is accompanied by absolute saving of fuel, as compared to lower velocity. «‘ We merely take it for granted, that the speed through the water will be nearly as the square root of the power, according to the general law of the resistance of fluids; that the resistance offered by bad weather or adverse winds has been ascertained, and is deter- mined on a particular station ; that is, that it is known that on a given station, a given vessel, with a given power, makes a voyage in adverse circumstances in, suppose, double the time of her most prosperous voyage ; (say her most prosperous voyage in 14 days, and her adverse voyage in 24 days, being a retarding power of 10 days out of 24;) we take this retardation of ten days as the measure of the retarding power of adverse weather in the given circumstances. 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