Feat E SS, a we BRE EEN STL ha , 1 j ‘ ‘ 42 ~ -_ ‘ 7 . " i i —_— { p | 5 an : \ hi! ; eT nL ae rd * } in ¢ hi’ " | 5 i a eee Pi he ‘ : ylang’ nye | be u ; , ii fr: a ae RY i ; i, ished ; i) ‘ . ite } H i ' i huey a beh nl I t h f ' ae ni vie vied cent ee Ae. Nyy) q, aan BAS fo | ‘ ( pry ? yn ee 2 re i in ‘ yl x {3 7 i Mig TO bi " ‘ i (as) | 4 i nt . F rats ¥ ; ' ee fy Oey 2 " An CO Mgr i a a , Mu 1 i ; Ve : , A in : oY re La al otal al ine } *y aa ‘ i ay ] f 7, 7 \ * iJ 4 : A , , ss j hs i D4 way , | 5 j t ‘ 9 ‘ = v y / ‘ & 1 / = 4 , > 4 » 7 / ‘a \ = * Li a > a” # ——_—~ ‘ / f ae Was oP j 4 ' “~— eh | ~ ’ ~ . ‘ oe i t , ai | - 1" = -_ , ' ‘ e * ; -_ "A i eet { A e pine ANd Rimi ‘ . REPORT OF THE FORTY-SECOND MEETING ar -*¢ _ & OF THE _, < BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE; - HELD AT BRIGHTON IN AUGUST 1872. LONDON: JOHN MURRAY, ALBEMARLE STREET, 1873. PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREFT. CONTENTS, Onsects and Rules of the Association Ce Places of Meeting and Officers from commencement rd Presidents: and Secretaries of the Sections of the Association from commencement eS Cw & see oe « 6 cles oa sig che eS eo ee he Br ew 8 8 Evening Lectures Ce Lectures to the Operative Classes SC Mrcasiter’s Account don os a Widoas Hes Od MO aS R ees Table showing the Attendance and Receipts at previous Meetings. . Officers of Sectional Committecs Officers and Council, 1872-73 Report of the Council to the General Committec.........6..0565 Ce Recommendations of the General Committce for Additional Reports BMV AMEREITCUES 1 SCIENCE. 6 Po.8 a. ek cm yh once ea + 988s Bs yee Synopsis of Money Grants......... ak biedehed.swovmal Hae! Place of Meeting in 1874 Pte Wee ne ae ae ee ee ee be ee BR TTR) ENTS) a8 General Statement of Sums paid on account of Grants for Scientific BUABUBOS oe. wih) nerduiysl to Eee ey paul Ceri nes Ces hadon Arrangement of the General Mectings ............. tee weer neces Address by the President, Dr. W. B. Carpenter, LL.D., F.R.S..... REPORTS OF RESEARCHES IN SCJENCE. Page XV1L XXLV XXX xl xlii xhii xliv xlvi xlvyii xlviii lini lix lx lxi Ixvili lxix Report on the Gaussian Constants for the year 1829, or a Theory of Terrestrial Magnetism founded on all available observations. By H. Prrersen and A, ERMAN ,....:.. bed. oes lee MEWS 1V CONTENTS. Second Supplementary Report on the Extinct Birds of the Mascarene isiands, -.by Aumaup Newion, MA. BORG. oo... etre wn on ale winoiniae Report of the Committee for Superintending the Monthly Reports of the Progress of Chemistry, consisting of Professor A. W. WixttaMson, F.R.S., Professor Franxianp, F.R.S., and Professor Rosco, F.R.8... Report on the best means of providing for a Uniformity of Weights and Measures, with reference to the Interests of Science, by a Committee, consisting of Sir Joun Bowring, F.R.S., The Right Hon. Sir Srarrorp H. Norrucorr, C.B., M.P., The Right Hon. Sir C. B. Apprrtey, M.P., Sauvurt Brown, F.S.8., Dr. Farr, F.R.S., Frank P. Frtiowns, Professor Franxianp, F.R.S., Janes Heywoop, F.R.S., Professor Lronr Levi, F.S.A., F.S.S., C. W. Srewens, F.R.S., Professor A. W. Wuttumson, F.R.S., Dr. Groner Grover, Sir JosepH Waitworrn, Bart., F.R.S., J. R. Naprur, J. V. N. Bazateerrrs, and Sir W. Farr- BE ATRUN SAI ae Ueatereeitee =o cieisw.s xe acaie «gis whens) uals canes ate keL ee ame Eighth Report of the Committee for Exploring Kent’s Cavern, Devon- shire, the Committee consisting of Sir Cuartus Lyett, Bart., F.R.S., Professor Pures, F.R.S., Sir Jonn Lupzocr, Bart., F.R.S., Jonny Evans, F.R.S., Epwarp Vivian, M.A., Grorex Busx, F.R.S., Wrrrram Boyp Dawxtns, F.R.S., Wittiam Aysurorp Sanrorp, F.G.8., and Wines Prnarciy, PRS. (Reporter) oo. 00... ee ees Ware's Report of the Committee appointed for the purpose of promoting the Foundation of Zoological Stations in different parts of the World Fourth Report on the Fauna of South Devon. By C. Spence Barn, F.R.S. Preliminary Report of the Committee appointed to construct and print Catalogues of Spectral Rays arranged upon a scale of Waye-numbers, —the Committee consisting of Dr. Hueeins, Mr. Locxyrr, Professor Reynotps, Professor Swan, and Mr. Sronry (Reporter) Third Report of the Committee appointed to consider and report on the various Plans proposed for Legislating on the subject of Steam-Boiler Explosions with a view to their Prevention,—the Committee consist- ing of Sir Wittr1am Farrzaren, Bart., C.E., F.R.S., &., Joun Penn, C.E., F.R.S., Frepuricxk J. Bramwett, C.E., Huca Mason, Samurn Riesy, Tuomas Scuorietp, Coarues F, Bryer, C.E., THomas Wensrer, Q.C., Epwarp Easron, C.E., and Lavineton KE. Frrrcumr, C.K. .... Report of the Committee, consisting of Jamns Guarsuer, F.R.S., of the Royal Observatory, Greenwich, Rozerr P. Gree, F.R.S., ALEXANDER S. Herscuzt, F.R.A.S., and Cuantus Brooxn, F.R.S., Secretary to the Meteorological Society, on Observations of Luminous Meteors, 1871— 72; drawn up by Atexanper 8, Herscuet, F.R.AS. ..........0. Experiments on the Surface-friction experienced by a Plane moving through water. By W. Frovps, F.R.S. Report on the Antagonism between the Action of Active Substances. By Tuomas R. Fraser, M.D., Secretary to the Committee, consisting of Sir R. Curistison, Bart., Dr, Laycocx, and Dr. Fraser selec) O15 0 0 .6)6 ue @e pie 2 ie he Fifth Report of the Committee, consisting of Sir W. THomson, F.R.S., ’ Professor Evrrerr, Sir Cuarres Lyerz, Bart., F.R.S., Professor J, 24 53 57 124 ; CONTENTS. Crrrk Maxwett, F.R.S., Professor Paitiies, F.R.S., G. J. Symons, F.M.S., Professor Ramsay, F.R.S., Professor Grrr, F.R.S., J. GuatsuErR, F.R.S., Rev. Dr. Granam, G. Maw, F.G.S., W. Pencerrty, F.RS., 8. J. Macxiz, F.G.S., Professor Hutz, I’.R.S., and Professor Awstep, F.R.S., appointed for the purpose of investigating the Rate of Increase of Underground Temperature downwards in various locali- ties of Dry Land and under Water. By Professor Everert, D.C.L., Lela heg idl et peli Ae ER PIP ar epee ara sey ai grein Pe Car a Preliminary Report of the Committee on Siemens’s Electrical-Resistance Pyrometer, consisting of Professor A. W. Writramson, F.R.S., Sir W. Tomson, D.C.L., F.R.S., and Professor J. Crmrk Maxwett, MABUMTVAEV ESS Werte tre cece crchcce oisge: Hee oo she ce are setae rtha! sake es oheges Fourth Report of the Committee on the Treatment and Utilization of Sewage, consisting of Ricuarp B. Granrnan, C.E., F.G.S. (Chair- man), Professor W. H. Corrrerp, M.A., M.D., J. Bartey Devon, C.E., F.G.S., Dr. J. H. Grinert, F.R.S., Jonn Toornait Harrison, C.E., W. Hors, V.C., Lieut.-Col. Leacu, R.E., Dr. A. Vortcxnr, F.RB.S8., and Professor A. W. Witt1amson, F.R.S. 2... eee ee ee Interim Report of the Committee appointed for the purpose of making experiments on instruments for Measuring the Speed of Ships and Currents by means of the difference of height of two columns of liquid, —the Committee consisting of Prof. W. J. Macavorn Ranking, C. W. Merririetp, F.R.S., Mr. F. J. Bramwetr, and Mr. Aurrep i. EMTCHER (DECTELATY) «fies owns wy ed seweld ons yey wayawele 6 ee Report on the Rainfall of the British Isles, by a Committee, consisting of Cuartes Brooke, F.R.S. (Chairman), J. F. Barrman, C.E., F.R.S., J. Guatsurr, F.R.S., R. W. Mytyz, C.E., F.R.S., Prof. J. Puiruies, F.R.S., T. Hawxstey, C.E., Prof. J. C. Apams, F.R.S., Prof. J. J. Syrvuster, F.R.S., C. Tomirson, F.R.S., R. Fretp, C.E., Dr. Por, C.E., F.R.S., Prof. D. T. Anstep, F.R.S., A. Bucnay, F.R.S.E., and SEPM INMONS s TICCLOCALY. © o-oo or oot wr vrera co een ew ooo nhsie aislglaldphaiallpye Report of the Committee, consisting of the Rey. Dr. Ginsnure, W. Hup- worth Dixon, Rev. Dr. Trisrramu, F.R.S., General Cuxsnry, Rev. Professor Rawxryson, and Joun A. Trxn£, appointed for the purpose of undertaking a Geographical Uxploration of the Country of Moab. . Sur l’élimination des Fonctions Arbitraires. By Cu. Heruire, Corr. Member of the Mathematical Society, London ...............0.. Report on the Discovery of Fossils in certain remote parts of the North- western Highlands. By Wiritam Jonty ............ fe SOP Report of the Committee on Earthquakes in Scotland. The Committee consists of Dr. Brycr, F.G.S., Sir W. Tomson, F.R.S., D. Mitye- ee Pre b Sitr . HOWE vn cee. ss oe anne ses cnbeneeneae Fourth Report of the Committee appointed to investigate the Structure of Carboniferous-Limestone Corals. The Committee consists of James Tomson, F.G.S8., and Professor Harxnuss, F.R.S. .........00005 Report of the Committee, consisting of J. F. Barrman, C.E., F.R.S., P. Le Neve Foster, M.A., C. W. Mereirierp, F.R.S., E. Easton, V Pege 128 134 176 176 210 233 238 240 241 vi CONTENTS. F.GS., F. J. Bramwert, C.E., W. Horz, Y.C., and H. Bavermay, F.G.8., appointed to consider the mode in which new Inventions and Claims for Reward in respect of adopted Inventions are examined and dealt with by the different Departments of Government, and to report on the best means of removing any real causes of dissatisfaction, as well as of silencing unfounded complaints ............-..000 eee: Report of the Committee for discussing Observations of Lunar Objects suspected of Change. The ‘Committee consists of the Rev. T. W. Wess, the Rev. Rosenr Harter, F.R.S., and Epwarp Crossiey, OCISRI Madu .WabieLti Ss iad. ale. Weaaad. PY gacieeey eee Report on the Mollusca of Europe compared with those of Eastern Nor ty Amoericn, By J. Gwyn Juvesuys, FURS... ci ee te ek nfo we Report of the Committee for the purpose of investigating the Chemical Constitution and Optical Properties of Essential Oils © 6[e. 6 a.m aspen oe. 92 @ Report of the Committee, consisting of the Rev. Canon Tristram, Pro- fessor Newron, H. E. Dresser, J. S. Hanrrye, and the Rey. A. F. Barnes, appointed for the purpose of continuing the investigation on » the desirability of establishing a “ Close Time ” for the preseryation of indigenous animals Sixth Report of the Committee appointed for the purpose of continuing Researches in Fossil Crustacea, consisting of Professor P. Marri Dunean, F.R.S., Henry Woopwarp, F.G.S., and Rosert Ernerres, F.R.S. Drawn up by Henry Woopwarp, F.G.S................. Report of the Committee appointed to organize an Expedition for ob- serving the Solar Eclipse of Dec. 12, 1871 Preliminary Report of a Committee, consisting of Professor Micnann Fostmr, F.R.S., Professor W. H. Frowrr, F.R.S., and Bensaury Lowne, M. R.CS., appointed for the purpose of making Terato-em- bryological Inquiries 0, On Ov Ope. Oy OvOLe He. Uo 10) oe, Ore. Cie p Ola 6 @ Biel avn ee te ole Bene Report on Recent Progress in Elliptic and Hyperelliptic Functions. By W. 4H. L. Russert, F.R.S. C18 CoC ee a git 8-y 0 eee 6 coe 2 © © Ole 5.800 60 ame men Report of the Committee appointed for the purpose of promoting the extension, improvement, and harmonic analysis of Tidal Observations. Consisting of Sir Wit11am Tomson, LL.D., F.R.S., Prof. J. C. Apaus, F.R.S., a OrpHAm, Witr1Am Parxrs, M. Tne. E., Prof. Rain, LL.D., R, R.S., and Admiral Ricwarps, R.N., F.R. .. osc Si— agai) ee On the Brighton Waterworks, By Epwarp Easton, C.E., F.G.8. .... On Amsler’s Planimeter. By F. J. Bramwetr, C.E. Page 243 320 CONTENTS. vii NOTICES AND ABSTRACTS or MISCELLANEOUS COMMUNICATIONS TO THE SECTIONS. MATHEMATICS AND PHYSICS. P Agdress by Wannen Dz LA Run, Esq, D.CL., Ph.D, PRS, V.P.C8,° V.P.R.A.S., President of the Section ..... SB ae ea eet the eae! | Marnewarres. Professor Ciirrorpd on the Contact of Surfaces of the Second Order with LET STL ESRI I A RCIEDERST eet ARTS DRO TENE PII TI cIcac Ceyripekgnatiowicd “arte 13 Mr. Matrurw Cotxrs on new Improvements in Approximating more rapidly than usual to Square, Cube, and other Roots of a given Number N ...... 15 Mr. J. W. L. Grarsuer on.the Evaluation in Series of certain Definite Integrals 15 on the Function that stands in the same Relation to Bernoulli’s Numbers that the Gamma-function does to Factorials ........ 17 — - on the Law of Distribution of Prime Numbers..... Pare a Mr. J. E. Hinearp on a Verification of the Probability Function ........ aye ee My. F. W. Newman on Tridiametral Quartan Curves ........++eeeee i ack ee on Quartan Curves with 3 or 4 Diameters ............ 23 on Monodiametral Quartan Curves ........eeeeeeeee . 23 Professor H, J, Srepuen Surry on the Circular Transformation of Mébius.. 24 GrneraL Puystcs. Mr. P. G. Tarr on Sympathy of Pendulums ... eee eee eee e eens eT eee Professor James Tromson on Relations between the Gaseous, the Liquid, and the Solid States of Matter .......ce eee ee ees Tw Dekeeeares DE caatahite 24 AsTRONOMY. Mr. Howarp Gruss on some new Points in the Mounting of Astronomical f MCSONCN cide Kc rine Cis pe seeAMACA eT Ue at to ee ee 30 Dr. JANssEN sur le Résultat de ses Observations dans I’Inde sur I’Eclipse du 12 a Bis ORR creo tate es eure ys tem te False oA ste ce dee gWiwleles Ty Dae vill CONTENTS. Lieut. Mr. J. H. Brown on Refraction and Solar Spots .......eeeeeeeee POOD On Professor CRouLLEBotIs on the Action of Quartz on Ultra-Violet Rays...... ——- on Tubes Phosphorescent by Friction ............ Professor J. D. Evrrrrt on Focal Lines...........00005 joey 2oOmNONG 1 Sodan ———— an a Difficulty in the Theory of Aberration ...... — ofl JMET Ge etO nol co Ssjetetenene Roto ma LDU san AOE Mr. Groner Fores on Astronomical Refraction ............eeeeeeenes Mr. Tuomas GArrietp on the Action of Sunlight on Colourless and Coloured GASSE FARIA Rcdistate clits ¢ + dl oe Sofetofolate a [oie te loys ale ols latela\ets whole whale daiue Meese as Mr. AnvHur ScuustTer on the Spectrum of Hydrogen .......0esseeeeees The Hon. J. W. Srrurr on the Application of Photography to copy Diffrac- tion-pratings .........06. SSO OMGGodooo ReGMOb GOO OUR os acc Professor JAmus THomson on Atmospheric Refraction of Inclined Rays, and Guuine Meat nao trey UOVel RAY Metre’. royeisicrsiers a c/o’ sieiiorelnarenrtoke) slereia tel setone oo. : Dr. T. OGreER Warp on a Phenomenon connected with Diffraction ........ Colonel Sruarr Worriry on the Importance of the Saits of Uranium in HSH OEG CHAD ygeerscecscereva,ene «ters viel eis ctarntesetentin sreicts ecadevalel oy els oie nate tei tee nema Professor Ch. V. ZencER on the Velocity of Light in the Chemical Elements, and on their Crystalline Form ........... aids vialisinse tele. aveawhe LSTeIOS a weiale OR Hear. Mr. W.F. Barrett on a Condition affecting the Spheroidal State of Liquids, and its probable effect on certain Boiler-Explosions .......+.sseeeeeeeee Dr. Witi1Am B, Carprnter on the General Oceanic Thermal Circulation .. Mr. JAmMEs Dewar on Recent Estimates of Solar Temperature ...... syevalisieie on the Temperature of the Electric Spark............+. Dr. J. Hopxrson on the Stresses produced in an Elastic Solid by Inequali- ties of Temperature............ Soda Sema SDUnAn Aca S aon sinncts ss ELECTRICITY AND MAGNETISM. Professor P. G. Tart on Double Neutral Points in Thermoelectric Currents . Mr. G. K. Wintrr on the Use of Electromagnetic instead of Electrostatic Induction Cable-Siomaliney wireless is, «sche cle nviearce ees/s sate arsine MurroroLoey. Rey. H. A. Bors on Greek Meteorology... 0s desu sintieeies ose vemle vanes M. W. pE Fonviriie on the Advantages of keeping Records of Physical Phenomena connected with Thunder-storms ........ 0... ceeceeeeeeeees Mr. Cuartres Mriprvm on a Periodicity in the Frequency of Cyclones in the Plndian ‘Ocean sowthvof thevHiquatOr ys jer jae sii sehelscas + suinsinainiels sine Mr. Freprrick Ernest SAWYER on the Rainfall of Sussex ...... onetys: heme ACOUSTICS. M. Ruportr Kénre on Musical Beats and Resultant Tones........... aes Mr, G, VANDELEUR LEE on the Human Voice as a Musical Instrument .... 58 OL CONTENTS. INSTRUMENTS. Mr. W. Marsuam Apams on the Mensurator, a new Instrument for the Solu- MOUEGH TIAN GIES: Lisishs9d baile elecatdsa'evayd lolers wig 8 ate dee way erate ya thoiatagys Pawn has Mr. Grorcr Dives on a new Hygrometer...... svaeiatanasey stat eg hes rey sestesetetes fe.c Dr. J. Hopxison on a Nautical Photometer ........ ccs cece cence eens Dr. JANSSEN sur un Nouveau Thermométre destiné & prendre les Températures de la Surface des Eaux Marines ou Fluviales ..........ccccceeeeseeeees Professor Joun Puiiires on the Temperature-correction of an Aneroid .... Mr. Macnem TriForp on the new Marriotti Barometer 1... sssseseeeeee Professor Cu. V. ZENGER on the Spiral Top ......ccccceeeeeeneees eevee —— on the Tangential Balance and a new Saccharometer ProGress oF SCIENCE. Lieut.-Col. A. Strraner on the Duty of the British Association with respect to the Distribution of its Funds .............00. a SOS MRL Cl, San CHEMISTRY. Address by J. H. GLApsToNE, Ph.D., F.R.S., President of the Section...... Dr. A. Crum Brown on Chemical Nomenclature.........cseeeccececeees Dr. F, Cracr-Catvert on the Relative Power of Various Substances in pre- venting Putrefaction and the Development of Protoplasmic and Fungus Life Mr. Winrram Lant CarprntTer on the Presence of Albumen in Neutral Fats, and on a New Process for the Manufacture of Stearic and Palmitic RMRATIS MORE PAE Re cig hen trek Aen Oo COI Ee Ee Shen ee —— ——-—-—~— on the Mode of Collection of Samples of Deep-sea Water, and of their Analysis for dissolved Gaseous Constituents, employed on board H.M.S. ‘ Poreupine’ during the Summers of 1869 and DEE ty as oh sfaN a fetetatataticCate a hat larch oforetots tv toNiatateretstaretttTe creel oleh Mea Miele Mr. W. J. Cooper on a proposed Method of preventing the Fermentation of SRR eta 595 Ca 0s S215 o ella as Har ral arab. te Parton rat yiire fo BOS MAMAN TD hb Mr. Jonn GaLietiy on Ignition of Cotton by Saturation with Fatty Oils .. Mr. GEorGE GLADSTONE on the Dust thrown up by Vesuvius during the late ERIE Se ti ahaha =: So PN Rae oss oO Oe earhidia'e wale le, Sede Melbshade ALOR, a Dr. J, H. Guapstone on filiform Native Silver............0. Rade ite watts ——_—— and Mr, Atrrep Trier on the mutual helpfulness of Chemical Affinity, Heat, and Electricity in producing the Decomposition of “OU THGIE. Ud dubstep cape tain Mcipacleas C00 11 CaaS DeDIG ocho SODA sigheretaraisth @ivalte loyal : The Rey. H. Hicuron on a Powerful Galvanic Battery ............00005 ; Professor J. W. Mauer on the effect upon Meteoric Iron, as regards the capa- bility of being forged, of previous heating to redness or whiteness zm vacuo . —— on the Fusion of Metallic Arsenic ...........0 i SBT Se TIMEX rate Taree eo otah tibetan RITICNa De tielel sayeth Syuinia. Gaara ued « asousress —__________——— on the occurrence in recent Pine timber of Fich- telite, a Hydrocarbon hitherto only known in a fossil state ..........00 08 Dr. T. Morrat on Dr. Moffat’s Tube Ozonometer..........cceeceeeceeecs ‘ Dr. OppeNHEIM on the Action of Phosphorus on Alkaline Solutions of Metals 1X 63 79 79 79 x: CONTENTS, Page Dy. Onp on the Crystallization of Salts in Colloid Solutions ....... Atousnigpe Ce, Terr G. vom Raru—The Crystallographic System of Leucite, hitherto sup- posedite helresularyis.qiadratic, 5 aisiere anne tle aiile'slo’s ecatelteme Btaralely fe. eae Mr. W. CuanpiEer Roperts on a Curve Illustrating the British Gold Coinage 82 Dy. R. Scuenk on the Amount of Heat required to raise Elementary Bodies from the absolute zero to their state of Fusion .......seeeeeeeees eshte, Wee Mr. T. KE. Taorpe on an improved form of Filter Pump .......seeees Teele MSs Mr, Atrrep TrieE on the Precipitation of Silver by Copper.......... io 84 Mr. G. Unwin, Specimens of Agate and other Natural Coiloid Silica ex- GTEC Ds Vasaccw sles « Gintdsine ole Lldtebvelahts watety ashe cecpenbareg ate gains Se Mr. J. F. Waxxer on Dinitrobrombenzene .........4. Ron ga Mi cn aos sqngtee Mr. J. ALFRED WANKLYN on the Continuous Production of Oxygen ...... 85 ——— on some New Methods of Analyzing the Hthers.. 85 Mr. WALTER WELDON on the Manufacture of Chlorine by means of Manga- BNUeNGE MIROTESITINA 7 5.2 y, 1 vein sg Sewers jalv giertuaie gle oie all santas (ousnehee eae Teer 86 Mr. Joun WixxiAms on the Preparation of Guaranine ..... 2 sachsen lea) 86 Dr. T. Woop on Teaching Elementary Chemistry to Boys under 14 years of Age 87 Mr. C. J. Woopwarp on a Modification of Hofmann’s Apparatus for Electro- (SSC 00 dA Re AS Se A) 9 8 eee ENR 87 Dr, C. R. A, Wricut on New Derivatives from Morphine-and Codeine .... 87 GEOLOGY. Address by Ropent A, C, Gopwin-Austern, F.R.S., F.G.S., &c., President GLEN ECLION WOGue ac common sm Hoe eC ao. 156 The Rey. Joun T, Guricx on Diversity of Eyolution under one set of External Conditions....... BRODER DOG HERI ONT De Menorca gnc ME TO 0 136 Capt. MarsHaLu Haxi on the employment of Yachts in Deep-sea Researches 156 Mr. J. Gwyn Jerrrrys on the Mollusca of Europe compared with those of astern North Amiericats. cc sic(sto-bwis aw aleldhe «aleltte.e/eilslele elesmetelate ie eoetne 137 My. I. T. Morr on the Theory of the Scientific Value of Beauty in relation to the doctrines of Mr. Darwin and Mr, Galton ........cce cece event eee ees 137 Dr. H. ALLEYNE NicHoson’s Preliminary Report onDredgings in Lake Ontario 137 Mr. R. A. Peacock, How a National Natural-History Museum might be builtiand airanged! withladvantage ~.. 2. cswsees ccs + ce cline sei ele cle Giant 158 Mr, Jonn Rogerson on the Perforating Instruments of Pholas candida .... 140 Mr. P. L. ScLatEr on anew Rhinoceros, with Remarks on the Recent Species of this Genus and their Distributions... .. 00.600 s kk ces tie de we ne see uibele 140 BA GITIC. iiote Wie overare eaters sun etactente Metal orate. sie feknnehece akaetel eis elton. ket ent 140 Mr. D, A. Spaipine on Instinct, with original Observations on Young Animals 141 Mr. J. F. Wuirraves on a Deep-sea Dredging-Expedition round the Island of Anticosti, in the Gulf of St. Lawrence..........++ DOGO DOOM oe sbi « .. 143 ANATOMY AND Puystonoey. Professor Burpon Sanpenson’s Address to the Department of Anatomy and HV ELOLORY, Osh otaa sein, Chfoisis nig etnias tasks ys ore ayer ape ea IS wom hela velo ake sha) ea 145 Prof. W. H. Frower on the Arrangement and Nomenclature of the Lobes of Be Maver ia Mem MIRNA 6... co e's 5c s 5» Sir seishig tak shine ois nalte mg igme wee 150 CONTENTS. xili Page Mr. Grorer Harrts on the Concurrent Contemporaneous Progress of Reno- yation and Waste in Animated Frames, and the extent to which such Opera- tions are controllable by Artificial Means ...... ccc cere eee ee eee nes 152 M. G. Poucuer on the Mechanism of the Change of Colour in Fishes and OINELCYU-E TAN eISSN OSC ICICI nena 7.0 TAC Annette AOz Dr. Rapcurrre on the Mechanism of Muscular Contraction ..........0005 152 Dr, James Ross on the Graft Theory of Disease ...... ese eee eee eeeeeeee . 153 Dr. Burpon SANDERSON on the Cause of the Respiratory Variations of Arte- rial Pressure........ basaaeicgara ata ier acatne A aS NTe aE RS Rr aiaty .. 154 Mr. E. A. ScuAren’s Experiments relating to the Coagulation of the Blood., 155 Professor Cart SEMPER on the Normal and Abnormal Growth of Zimneus . 166 Professor SrRuTHERS on the Occurrence of the Supracondyloid Process in ei sis Wiel ciusles Side «9% 9 ops Seine uae Faas glee eee Lieut.-Colonel J. A. Gran on Dr. Livingstone’s Recent Discoveries ..,... 2C9 The Rey. Epwarp Harz on the Place of Geography, Political and Physical, in'Widucation Wiis i Ais ad DR pa eae 209 Mr. H. H. Howorrn on Recent Changes of Level in Land and Sea........ 210 Capt. Frrrx Jonzs on the Direct Highway to India considered ..........4- 210 Mr. G. LemorneE on the Relation of Forests to Hydrology ...:.....5e00: 210 Extracts from the Official Despatches of Dx, Livingstone,,......+. RA wy act CONTENTS. KV Mr, W. F. Mayers on the Panthays of Yunnan ssessssssssncieietevees ‘ Bil Mr, A. Mossman on the Topography of Yeddo vi svsvevece tee ee tace renee 211 Capt. SHerarp Osborn on Polar Exploration ..... 0. sseseee eee e eee eees 211 Mr. R. B. Saaw on the Physical Features of the Pamir and its Aryan in- habitants ...... sists hoi otete ssi eek sustotele Aidit Ghee TAP shiaet gh Sees Reinissost uth ae 213 My. H. M. Sranuey on Discoveries at the Northern End of Lake Tanganyika 213 General R. Srracuey on the Scope of Scientific Geography, illustrated by Remarks on the Climate of British India ..... ss esse eee eee sees Spagetti taaheeek = Sir G. Youne on the Question “Is the Asiatic Emigration to the West Indies likely to be a Permanent Fact in Modern Geography?” ........ sey LD ECONOMIC SCIENCE ann STATISTICS. Address by Professor H. Fawcett, M.P., President of the Section ......., 217 Major-General Sir Jamzs HE, ALEXANDER on the Pollution of Rivers ...... 220 Miss Lypra E. Becker on Statistics regarding the Attendance and Hducation of Girls in the Elementary Schools of Manchester ..............eeeseee 220 Instruction of School-Board Pupils in the Higher Branches of Knowledge . 222 Mr. Herpert Burcess on International Decimal Coinage.............05- 222 Mr. Hypr Crarxe on Polygamy as affecting Population...........:.0eees 224 Mr. Frank P. Freiiowss’s Suggestions for improving and extending our National Accounts; being a continuation of Mz, Fellowes’s Paper read at the Edinburgh Meeting, “On a proposed Doomsday Book, &c.”......... . 224 Professor Hutt on a Proposal for supplying Pure Water to Villages and Country Parishes in Central and Eastern Divisions of England ........., 226 Miss SurrrerF on the National Union for Improving the Education of Women 226 Dr. Epwarp Smiru on the Economic and Nutritive Value of the three prin- cipal Preserved Foods, viz. Preserved Milk, Preserved Meat, and Liebig’s Extract of Meat ......... Stn ne ana CE NS MAC! . 227° MECHANICAL SCIENCE. Address by Freperrcx J. Bramwext, C.K, President of the Section ...... 227 Mr. CO. Bergeron on the Rapid and Economical Transport of Merchandise ., 241 Mr. D. T. Bosren on a Modification of the Harth-Closet..............0005 241 My. C. A. Bowpier on Aérial Nayigation...... Ono £3. -alona suites A estar ess 241 | Mr. D. Carrer on a Modification of the arth-Closet............e0cee eee 242 Mr. Hypr Crarke on the Progress of the Through Railway to India ...... 242 - Mr. J. P. Corsron on the Drainage of Shoreham................ CAD os BAP Mr. T. Curiry on the Sewage Difficulty ................ AOE SOOO MOL 242 Mr. C. IF’. Dennet on Breach-Loading Firearms ........cscceeeeeeeeeeee 242 Mr. RicHarp Haron on certain Heonomical Improvements in the Construction of Locomotive Engines, by the addition of Mechanical Appliances for the use of Heated Air in combination with Steam, on the principle invented by POEMS NVIATSOD OW ahetays, sielely avcieiesvte Vula/elolansiaia’s. clevesuhertione (aiaalSiis 245 3 Mr. W. R. Ecxart on Marine Propulsion ,..,.... Rarer Someone prnOk. 24: XV1 CONTENTS. Page Mr. W. Friemrne on the Steering of Ships, in special relation to a new form on ndder perieess sales: seth e eastaie tole bel oqavevolouciale aeg’ site ete Reel 243 Mr. P. Lz Neve Foster, Jun., Description of the New Branch Canal leading from the Canal Cavour for Inrigating the Province of Lomellina.......... 245 Mr. W. Frovpn’s Description of an Apparatus for automatically recording the Rolling of a Ship in a Seaway wv... cece cece nsec teen eee eee ee nes 245 Mr. Joun G. GAMBLE on the Brighton Intercepting and Outfall Sewers .,,, 245 Mr. AtrxanpER M‘Catium Gorpon on the Distribution of Pure Water to MD VCMMNOA ery a ee gee tis cies. es te 90 cle > vie une 0 90) ei0 ei etpjetses’sielsiis/elyialstabe ts ers 246 Mr. E. J. Hrtx on Boat-lowering Apparatus .. cc. cece cece ete eee ieteatestts 246 Mr. HODGSON on Wire (ramways ai: c« ses. 0 0c © aistesioltipiole e steele cele . 246 Mr. W. Horr on the Estimation of the Error in the Flight of Heavy Projec- tiles due to the Woolwich System of Rifling ......... cc cece cece ne ee ees 246 Mr. C. W. Merrrrievp on the Measurement of Waves ..........00008 vee 246 Mr. Wii11am Pavt on the relative Value of Clarified and Unclarified Sewage PISPHMNUATLURG My Meteyatace sicotcta stare elsieie clotemterstoe TRO oid oh os oN - patente een Mr. Freprrick Ransomm on some Recent Improvements in the Manufacture of Artificial Stone, and the Application of such Stone to Constructive and Sblier PURPOSESa ss. o0ssjeo nein aee os paws sean On 05.0. nhs oin a slop 248 Maj.-Gen. H. Y. D. Scorr on Defecating Sewage and Utilizing the Deposit for the preparation of Lime and Cement ...,......seesereesseeenctnecs 250 ——_—_—__-—— on the Agricultural Value of the Lime Compounds obtained iby, Wefecatimo ge waeer. esis oct iele cine stories terre afetelelele eteretetaeteieatets 250 on the Selenitic Method of making Mortar...... 250 Mr. Jonn Smyru, Jun., on an Apparatus for testing the Water-stopping effi- ciency of Clay Soils and other Substances under various pressures ......., 250 Mr. W. Symons on a Plan for Railway Amalgamation with Government Glory) eS RaRRE Hine Oe diaomon 0 ino Tato OOOO MSD UraOGmAT TC oot ome 251 Prof. Sir W. Tomson on the use of Steel Wire for Deep-sea Soundings.,... 251 on the Identification of Lights at Sea............4- 251 » Mr. A. Upwarp on Drilling-Apparatus for Gas- and Water-Mains ........ 252 Mr. THomas WessTER on the advancement of Science due to Patented In- VOUULOMS Er sietesers) elas eats ipAowo pc ac Avin alate » wale dimpic’s si eai6's «10 5 ova eee Mr. A. Wytrik& on the Progress of Invention in Breech-loading Small Arms during the past Twenty Years ........++005 Joodoono £06 Ameryoto oxi cuge.0 252 ERRATA IN REPORT FOR 1871. In Mr. Peacock's paper, p. 240 (Trans. of Sections) :— In second paragraph, line 2, dele and. In line 5 of same paragraph, for 8 read 2. ERRATA IN THE PRESENT VOLUME, Page 352 (Reports), line 8 from bottom, for Je(v,—}myr+hd i...) read I(v,—myr +6,2... )s », 108 (Trans, of Sections), line 27, for radiatus read radicans. OBJECTS AND RULES or THE ASSOCIATION. OBJECTS. Tur Assoctatton 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 Science in different parts of the British Empire, with one an- other and with foreign philosophers,—to obtain a more general attention to the objects of Science, and a remoyal of any disadvantages of a public kind which impede its progress. RULES. Admission of Members and Associates. All persons who haye attended the first Meeting shall be entitled to be- come Members of the Association, upon subscribing an obligation to con- form to its Rules. The Fellows and Members of Chartered Literary and Philosophical So- cieties publishing Transactions, in the British Empire, 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 Mem- bers of the Association. All Members of a Philosophical Institution recommended by its Counci or Managing Committee shall be entitled, in like manner, to become Mem- bers of the Association. Persons not belonging to such Institutions shall be elected by the General Committee or Council, to become Life Members of the Association, Annual _ Subscribers, or Associates for the year, subject to the approval of a General Meeting. Compositions, Subscriptions, and Privileges. Tare Mewsrrs shall pay, on admission, the sum of Ten Pounds. They shall receive gratuitously the Reports of the Association which may be pub- 1872. ‘ b rf XVili RULES OF THE ASSOCIATION. lished after the date of such payment. They are eligible to all the offices of the Association. Aynvat Sunscrrpers shall pay, on admission, the sum of Two Pounds, and in each following year the sum of One Pound. They shall receive gratuitously the Reports of the Association for the year of their admission and for the years in which they continue to pay without intermission their Annual Subscription. By omitting to pay this Subscription in any particu- lar year, Members of this class (Annual Subscribers) lose for that and all future years the privilege of receiving the volumes of the Association gratis : but they may resume their Membership and other privileges at any sub- sequent Meeting of the Association, paying on each such occasion the sum of One Pound. They are eligible to all the Offices of the Association. Asgocrares for the year shall pay on admission the sum of One Pound. They shall not receive gratuitously the Reports of the Association, nor be eligible to serve on Committees, or to hold any office. The Association consists of the following classes :— 1. Life Members admitted from 1831 to 1845 inclusive, who have paid on admission Five Pounds as a composition. 2. Life Members who in 1846, or in subsequent years, have paid on ad- mission Ten Pounds as a composition. 3. Annual Members admitted from 1831 to 1839 inclusive, subject to the payment of One Pound annually. [May resume their Membership after in- termission of Annual Payment. | 4, Annual Members admitted in any year since 1839, subject to the pay- ment of Two Pounds for the first year, and One Pound in each following year. [May resume their Membership after intermission of Annual Payment. | 5. Associates for the year, subject to the payment of One Pound. 6. Corresponding Members nominated by the Council. And the Members and Associates will be entitled to receive the annual volume of Reports, gratis, or to purchase it at reduced (or Members’) price, according to the following specification, viz. :— 1. Gratis.—Old Life Members who have paid Five Pounds as a compo- sition for Annual Payments, and previous to 1845 a further sum of Two Pounds as a Book Subscription, or, since 1845, a further sum of Five Pounds. New Life Members who have paid Ten Pounds as a composition. Annual Members who have not intermitted their Annual Sub- scription. 2, At reduced or Members’ Prices, viz. two thirds of the Publication Price.—Old Life Members who have paid Five Pounds as a composition for Annual Payments, but no further sum as a Book Subscription. Annual Members who have intermitted their Annual Subscription. Associates for the year. [Privilege confined to the volume for that year only. | 3. Members may purchase (for the purpose of completing their sets) any of the first seventeen volumes of Transactions of the Associa- tion, and of which more than 100 copies remain, at one third of the Publication Price, Application to be made at the Office of the Association, 22 Albemarle Street, London, W. RULES OF THE ASSOCIATION, XIX Volumes not claimed within two years of the date of publication can only be issued by direction of the Council. Subscriptions shall be received by the Treasurer or Secretaries. Meetings. The Association shall meet annually, for one week, or longer. The place of each Meeting shall be appointed by the General Committee two years in advance; 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 :— Crass A. Prurmanent Members. 1. Members of the Council, Presidents of the Association, and Presidents of Sections for the present and preceding years, with Authors of Reports in the Transactions of the Association. 2. Members who by the publication of Works or Papers have furthered the advancement of those subjects which are taken into consideration at the Sectional Meetings of the Association. With a view of submitting new claims under this Rule to the decision of the Council, they must be sent to the Assistant General Secretary at least one month before the Meeting of the Association. The decision of the Council on the claims of any Member of the Association to be placed on the list of the General Committee to be final. Crass B. Trumporary Members. 1. Presidents for the time being of any Scientific Societies publishing Trans- actions or, in his absence, a delegate representing him. Claims under this Rule to be sent to the Assistant General Secretary before the opening of the Meeting. 2. Office-bearers for the time being, or delegates, altogether not exceeding three, from Scientific Institutions established in the place of Meeting. Claims under this Rule to be approved by the Local Secretaries before the opening of the Meeting. 3. Foreigners and other individuals whose assistance is desired, and who are specially nominated in writing, for the Meeting of the year, by the Pre- sident and General Secretaries. 4, Vice-Presidents and Secretaries of Sections, Organizing Sectional Committees*. The Presidents, Vice-Presidents, and Secretaries of the several Sections ‘are nominated by the Council, and have power to act until their names are submitted to the General Committee for election. _ From the time of their nomination they constitute Organizing Committees for the purpose of obtaining information upon the Memoirs and Reports likely to be submitted to the Sections+, and of preparing Reports thereon, * Passed by the General Committee, Edinburgh, 1871. t Noté ce Contributors of Memoirs.— Authors are reminded that, wnder an arrange- ment dating from 1871, the acceptance of Memoirs, and the days on which they are to be — xX RULES OF THE ASSOCIATION. and on the order in which it is desirable that they should be read, to be pre- sented to the Committees of the Sections at their first Meeting. An Organizing Committee may also hold such preliminary Meetings as the President of the Committee thinks expedient, but shall, under any cireum- stances, meet on the first Wednesday of the Annual Meeting, at 11 a.m., to settle the terms of their Report, after which their functions as an Organizing Committee shall cease, Constitution of the Sectional Committees*. On the first day of the Annual Meeting, the President, Vice-Presidents, and Secretaries of each Section having been appointed by the General Com- mittee, these Officers, and those previous Presidents and Vice-Presidents of the Section who may desire to attend, are to meet, at 2 p.m., in their Com- mittee Rooms, and enlarge the Sectional Committees by selecting individuals from among the Members (not Associates) present at the Meeting whose as- sistance they may particularly desire. The Sectional Committees thus con- stituted shall have power to add to their number from day to day. The List thus formed is to be entered daily in the Sectional Minute-Book, and a copy forwarded without delay to the Printer, who is charged with publishing the same before 8 a.m. on the next day, in the Journal of the Sectional Proceedings. Business of the Sectional Committees. Committee Meetings are to be held on the Wednesday at 2 p.m., on the following Thursday, Friday, Saturday, Monday, and Tuesday, from 10 to 11 a.m., punctually, for the objects stated in the Rules of the Association, and specified below. The business is to be conducted in the following manner :— At the first meeting, one of the Secretaries will read the Minutes of last year’s proceedings, as recorded in the Minute-Book, and the Synopsis of Recommendations adopted at the last Meeting of the Association and printed in the last volume of the Transactions. He will next proceed to read the Report of the Organizing Committee +. The List of Communications to be read on Thursday shall be then arranged, and the general distribution of business throughout the week shall be provisionally appointed. At the close of the Committee Mecting the Secretaries shall forward to the Printer a List of the Papers appointed to be read. The Printer is charged with publishing the same before 8 a.m. on Thursday in the Journal. On the second day of the Annual Meeting, and the following days, the read, are now as far as possible determined by Organizing Comimittees for the several Sections before the beginning of the Meeting. 1t has therefore become necessary, in order to give an opportunity to the Committees of doing justice to the several Communications, that each Author should prepare an Abstract of his Memoir, of a length suitable for in- sertion in the published Transactions of the Asssciation, and that he should send it, toge- ther with the original Memoir, by book-post, on or before .. ...c0....ecseeeeseceeee , addressed thus—‘ General Secretaries, British Association, 22 Albemarle Street, London, W. For Section ......-” If it should be inconvenient to the Author that his Paper should be read on any particular days, he is requested to send information thereof to the Secretaries in a separate note. * Passed by the General Committee, Edinburgh, 1871. t This and the following sentence were added by the General Committee, 1871, RULES OF THE ASSOCIATION. XXi Secretaries are to correct, on a copy of the Journal, the list of papers which have been read on that day, to add to it a list of those appointed to be read on the next day, and to send this copy of the Journal as early in the day as possible to the Printers, who are charged with printing the same before 8 a.m. next morning in the Journal. It is necessary that one of the Secretaries of each Section should call at the Printing Office and revise the proof each evening. Minutes of the proceedings of every Committee are to be entered daily in the Minute-Book, which should be confirmed at the next meeting of the Committee. Lists of the Reports and Memoirs read in the Sections are to be entered in the Minute-Book daily, which, with all Memoirs and Copres or Abstracts of Memoirs furnished by Authors, are to be forwarded, at the close of’ the Sec- tional Meetings, to the Assistant General Secretary. The Vice-Presidents and Secretaries of Sections become ea officio temporary Members of the General Committee (vide p. xix), and will receive, on ap- plication to the Treasurer in the Reception Room, Tickets entitling them to attend its Meetings. The Committees will take into consideration any suggestions which may be offered by their Members for the advancement of Science. They are specially requested to review the recommendations adopted at preceding Meetings, as published in the volumes of the Association and the communi- cations made to the Sections at this Meeting, for the purposes of selecting definite points of research to which individual or combined exertion may be usefully directed, and branches of knowledge on the state and progress of which Reports are wanted; to name individuals or Committees for the exe- cution of such Reports or researches ; and to state whether, and to what de- gree, these objects may be uscfully advanced by the appropriation of the funds of the Association, by application to Government, Philosophical Insti- tutions, or Local Authorities. In case of appointment of Committees for special objects of Science, it is expedient that all Members of the Committee should be named, and one of them appointed to act as Secretary, for insuring atiention to business. Committees haye power to add to their number persons whose assistance they may require. The recommendations adopted by the Committees of Scctions are to be registered in the Forms furnished to their Secretaries, and one Copy of each is to be forwarded, without delay, to the Assistant-General Secretary for pre- sentation to the Committee of Recommendations. Unless this be done, the Recommendations cannot receive the sanction of the Association. N.B.—Recommendations which may originate in any one of the Sections must first be sanctioned by the Committee of that Section before they can be referred to the Committee of Recommendations or confirmed by the General Committee. Notices Regarding Grants of Money. Committees and individuals, to whom grants of money have been entrusted by the Association for the prosecution of particular researches in Science, are required to present to each following Meeting of the Association a Report of the prdgress which has been made ; and the Individual or the Member first named of a Committee to whom a money grant has been made must (pre- viously to the next meeting of the Association) forward to the General XXil RULES OF THE ASSOCIATION. Secretaries or Treasurer a statement of the sums which haye been expended, and the balance which remains disposable on each grant. Grants of money sanctioned at any one meeting of the Association expire a week before the opening of the ensuing Meeting; nor is the Treasurer authorized, after that date, to allow any claims on account of such grants, unless they be renewed in the original or a modified form by the General Committee. No Committee shall raise money in the name or under the auspices of the British Association without special permission from the General Committee to do so; and no money so raised shall be expended except in accordance with the rules of the Association. In each Committee, the Member first named is the only person entitled to call on the Treasurer, W. Spottiswoode, Esq., 50 Grosvenor Place, London, S.W., for such portion of the sums granted as may from time to time be required. In grants of money to Committees, the Association does not contemplate the payment of personal expenses to the members. In all cases where additional grants of money are made for the continua- tion of Researches at the cost of the Association, the sum named is deemed to include, as a part of the amount, whatever balance may remain unpaid on the former grant for the same object. All Instruments, Papers, Drawings, and other property of the Association are to be deposited at the Office of the Association, 22 Albemarle Street, Piccadilly, London, W., when not employed in carrying on scientific inquiries for the Association. Business of the Sections. The Meeting Room of each Section is opened for conversation from 10 to 11 daily, Zhe Section Rooms and approaches thereto can be used for no notices, exhibitions, or other purposes than those of the Association. At 11 precisely the Chair will be taken, and the reading of communica- tions, in the order preyiously made public, be commenced, At 3 p.m. the Sections will close. Sections may, by the desire of the Committees, divide themselves into Departments, as often as the number and nature of the communications de- livered in may render such divisions desirable. A Report presented to the Association, and read to the Section which originally called for it, may be read in another Section, at the request of the Officers of that Section, with the consent of the Author. Duties of the Doorkeepers. 1.—To remain constantly at the Doors of the Rooms to which they are ap- pointed during the whole time for which they are engaged. 2.—To require of every person desirous of entering the Rooms the exhibi- tion of a Member’s, Associate’s or Lady’s Ticket, or Reporter’s Ticket, signed by the Treasurer, or a Special Ticket, signed by the Assistant- General Secretary. 3.—Persons unprovided with any of these Tickets can only be admitted to any particular Room by order of the Secretary in that Room, No person is exempt from these Rules, except those Officers of the Asso- ciation whose names are printed in the Programme, p. 1, RULES OF THE ASSOCIATION. XXili Duties of the Messengers. To remain constantly at the Rooms to which they are appointed, during the whole time for which they are engaged, except when employed on mes- sages by one of the Officers directing these Rooms, Committee of Recommendations. The General Committee shall appoint at each Meeting a Committee, which shall receive and consider the Recommendations of the Sectional Committees, and report to the General Committee the measures which they would advise to be adopted for the advancement of Science. All Recommendations of Grants of Money, Requests for Special 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 Association to assist in making arrangements for the Meetings. Local 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 Secretaries, and a Treasurer shall be annually appointed by the General Committee. Council. In the.intervals of the Meetings, the affairs of the Association shall be ma- naged by a Council appointed by the General Committee. The Council may also assemble for the despatch of business during the week of the Meeting. Papers and Communications. The Author of any paper or communication shall be at liberty to reserve his right of property therein, Accounts. The Accounts of the Association shall be audited annually, by Auditors appointed by the General Committee. eee eee ewe "a'd UosmIqoy be 6 eu ‘oy . ‘wr: . ir . . . . _ baa a ava ee SEO S wea Tod “aK oe jd H9q0u aS WOH aie | SVU “VIN “C'd ‘NOSNIGOU UL "ATU UL ul: BOER UO LOGIC ‘aq ‘Aopsoq01A\ PLOT IYL Mout HY JO [LVq OUT, “**"S par] "4g jo doysig ploy aq "SoU “OW “Dsq ‘URIATA “H "¢) "CW ON TA) eee eaaeetes ‘esol UA Sad “bsop ‘UAMT TIC “AA SIMOT | *SEST ‘6 ysnSNy “VASNVAIS ‘bsg ‘98puSz0yy MIL pene tet . : : Sw a ‘gepuryy jo uvacr aut "AQT Ara A oUL ee ‘oy ‘4ya100g yefoyr eee eee eeeteeeesegeareg a ae ue Sos ee REY a eens prema SW “WH ‘TWes0d Jold Aa oUL ‘Sud “aw ‘Auaqneq Jossajorg “wea “bsg ‘purpy mone tH) “Sut “Cd ‘aysumugsa ay Jo uvad ayy “Aoy Ay9A_ *psojxO “Ze81 ‘ez aune ‘ax0Axo EEG Sees * Jo Azisr9Atu aU 105 ‘LN “TOE “bsa janooysq [euyong “9 svwmoyy, pT * PxOJXO JO APIsIVATU) 2Y} IO: SW CVT aqeAn soqou Ay | 2S EN OAL Oe aes ee haa TaN Sah ee cor ain CeoTA an | © > , pics sebelah ges Sa ali les heupaphatacaareateyy sedate ae a gears = eos i ie a Suu “To'd “wg “SIIONI AUUVH LUAAOU UIS fs sie ere sree’ trees ege w a ‘esod Iossajolg ‘SUA “A'W “WamoC sossajorg Sroraavaneta vere srelaTemrnieseinieie moe soapy ‘pioyxo 30 doystel prog OUL "CW te{9 Aue regia +5 sayy rAQyaT MCYS SApCYO “WOH WIN (*SWA'S 9 coelanrecangh aaegetatte eda MAES MEET Ee 4'S'3S'0'9 ‘NOSIHOUNW ATA MOIMAACOU WIS \ sreeseeeeurrorg ‘psnoLOgIeA JO [ALY oy, “AasayoutA\ Jo sinbivyy OYL “beg “Apooyy “9 *H * it i TOT reee eee eee eee ee ees ‘SU Soyer Ww ‘yorn3pag IOSsajorg "ADIT ouL sara Tord “wt “bsg ‘Airy “a “5 “arg ‘aysury "9 ‘ey “C'd “weyeID *¢ AON ORIN 1H) 7.8 (iy ip (0) doysig auL *ayoIMpivH jo bea ouL “S'uU'd CVI ‘paysuy Jossajorg . « Nu "Ss" a a ow “bsg ‘surdoy wey ei L Selis tlt ig seeeewon “Sard “Wed “TEHOSUUH “AA “A NHOL UIS be treeeeeerourer Gog “qi “Weg ‘uoyuNTIS *T, 231005) | “OFS ‘Ol Jaquiajdag ‘NOLAWVHLNOG "Sd “CTT ‘Aqseroag * AA “Ae Tere reer ee ee eee eee ee ee ‘Sma “T'O'd “beg ‘Aepeary javyorpy “spa “bsg ‘Tjeudeyy semouy,) ‘sua CHM ‘19IsMoIg praeq Ig “AW ‘AePHOA\N HENS UYor “UOH Iy.1, song “bsg ‘prepen mem Cet gota “qredioyy FunoosrA "SU ‘WUyMz I y [Le "PEST ‘gz raquiaydog ‘wa0X *bsq “989A4 WRIT AA phrenic’ vee th OR oer i Me Siete pe tees Sr OL, "qanod10 FT “ATMA *A9%T ore ‘(Algq JO uved) “a'd ‘MOOOVAd ‘9D “AGU UL sod Cah “Tod “bsg ‘soumryy woyouoyy “a ) eee eee pisegys y' ci tony W “bso * Tleqsavyy yey sour seecesereseccces SINTIQuUiED ‘aB0]109 Aguuay, JO 1ayse yy "SSL “Zo Joqmojzdag ‘sammy “Sv wd “Sd SW OH “Saad “ad Tease AA "MM “Aa OL, ee tunasnyy Ys 343 seeseeouge gr “oad San “qaeg ‘uowe8g” Aory svdjeyy ap diyiyg mu | 0 syuoujredaq Ar0ysty{-[eanNyeNY 9y4 jo. quepuejuuedng ibis Pie nie ielSi? 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Sreseeeererereceescesmcur ey “bs ‘XO Wa JOqOU eas oe ogre OST “CNL aqwadany “ef OETA 6st ‘et nny “sanaxg 5 Bg ee UII STDS Wa 2 doe ‘Suumog wor aig (**'s'wa “T'0'd ‘SAMOLS “9 TOUOTD uossasoud sviwa “bse sure ‘Ss AwoH | ooo eaeny “qaeg “ao ‘I09]ION "A PLOBMS tg ‘OH TUBA OUT, Le er a ee ee ace aueia cul Care veeeoses coer y “ony “aryl Why “bs oq xoq HM + oSpuquivg jo Ajisxaatuy) 94 UT Aayaur0as) Boe) Au0u0ssy JO 10889}01g . ° uvapumoy “Syd “Sia “Tod “wt “bsg ‘suupy yonop wyoe . jTonon gpm wonwo sou | SIOELTE SES sora eet sad 0M OHNE MOL ES | oonnos veces ‘SgBCLOUNN RNY SOUR TON oe eg ‘wit = seeeeees gGpraquing yo Ajtsdaatuy) 943 Ut ADO[OIS) JO LOSSIJOIg UBIPITM © | cone Creo “CY * : -aiduuiaye pleuod “Ad lz it Teg Pee ey Maar “WN Somapos wepy “soy oqg,| STE “prod “CN ‘ANOOH NOLIVG Hdasor sec ccccecccensccsdccesesvcccsccssocssc ces ccbgryr ae yoseyod | eeeceeseesesesseeeeseeseseseeeee "SUA “qed ‘neaplog 1999d uyor ag ++** yposxONT Jo FUBMaNOTT] -psoT ‘19}89010T JO [AVA 947 “MOH 343 ey) XXX REPORT—1872. Presidents and Secretaries of the Sections of the Association. | Date and Place. | | Presidents. 1832. 1833. 1834. 1830. 1836. 1837. 1838. 1839. 1840. 1841. 1842. 1843. 1844, 1845. Secretaries. MATHEMATICAL AND PHYSICAL SCIENCES. COMMITTEE OF SCIENCES, IL—MATHEMATICS AND GENERAL PHYSICS. Oxford Cambridge Edinburgh seenee Dublin .... Bristol ...... Liverpool .. Neweastle... Birmingham Glasgow Plymouth... Manchester York .....00a Cambridge. . 1846. Southampton 1847. 1848. 1849. . Edinburgh. 1853. 1854. 1855. . Belfast Oxford sednee Swansea .... Birmingham . Ipswich...... Liverpool... Glasgow 1856. Cheltenham 1857. Dublin ..|Rey. Dr. Robinson Davies Gilbert, D.C.L., F.R.S8... SECTION A.—MATHEMATICS Rey. William Whewell, F.R.S. ,|Sir D. Brewster, F.R.S............. Sir J. F. W. Herschel, Bart., E.R.S. Rey. Prof. Whewell, F.R.S. ... Rey. Prof. Lloyd, F.R.S. Very Rey. G. Peacock, ‘D.D., F 4 RS. Prof. M‘Culloch, M.R.T.A. ... The Earl of Rosse, F.R.S.......... The Very Rev. the Dean of Ely . F.R.S. Rev. Prof. Powell, M.A., F.R.S. . Lord Wrottesley, F.R.S. ........ William Hopkins, F.RB.S.......... Prof. J. D. Forbes, F.R.S., Sec. R.S.E. L. & E. The Dean of Ely, F.R.S. ........ L. & EK. Rey. R. Walker, M.A., F.R.S. ... M.R.LA,. Sir John F. W. Herschel, Bart., Rev. W. Whewell, D.D., F.BS., &e. Prof. W. Thomson, M.A., F.R.S. Rey.T. R. Robinson, D.D.,F.R.S., .|Rev. H. Coddington. Sir D. Brewster, F.R.S............- Prof. Forbes. Rev. W. Whewell, F.R.S.......... Prof. Forbes, Prof. Lloyd. AND PHYSICS. Prof. Sir W. R. Hamilton, Prof, Wheatstone, ...|Prof. Forbes, W. 8S. Harris, F. W. Jerrard. W. 8S. Harris, Rey. Prof. Powell, Prof. Stevelly, Rey. Prof. Chevallier, Major Sabine, Prof. Stevelly. ..|J, D, Chance, W. Snow Harris, Prof. .../Prof, Forbes, F.R.S. ......:.c0s000- Stevelly. Rev. Dr. Forbes, Prof. Steyelly, Arch. Smith. ..|Prof. Stevelly. Prof. M‘Culloch, Prof, Stevelly, Rev. W. Scoresby. +d. Nott, Prof. Stevelly. Rev. Wm. Hey, Prof. Stevelly. Rev. H. Goodwin, Prof. Stevelly, G. G. Stokes. a G. John Drew, Stokes. Rey. H. Price, Prof. Stevelly, G. G. Stokes. Dr. Stevelly, .|Dr. Stevelly, G. G. Stokes. Prof. Stevelly, Ridout Wills. W. J. Macquorn Rankine, Prof. Smyth, Prof. Stevelly, Prof. G. G. Stokes. 8. Jackson, W. J. Macquorn Rankine, Prof. Stevelly, Prof. G. G. Stokes. Prof. Dixon, W. J. Macquorn Ran- kine, Prof. Stevelly, J. Tyndall. G. G. Stokes, W. .|B. Blaydes Haworth, J. D. Sollitt, Prof. G. G. Stokes, M.A., Sec. RS. ...|Rey. Prof. Kelland, M.A., F.R.S. Prof. Stevelly, J. Welsh. J. Hartnup, H. G. Puckle, Prof. Stevelly, J. Tyndall, J. Welsh. Rev. Dr. Forbes, Prof. D. Gray, Prof, Tyndall. C. Brooke, Rey. T. A. Southwocd, Prof. Stevelly, Rey. J. C. Turnbull. Prof. Curtis, Prof. Hennessy, P. A. Ninnis, W. J. Macquorn Rankine, Prof. pias VE ese eee PRESIDENTS AND SECRETARIES OF THE SECTIONS. Date and Place. 1858. 1859. 1860. 1861. 1862. 1863. 1864. 1865. 1866. 1867. 1868. 1869. 1870. 1871. 1872. * 1832. 1833. 1834. 1835. 1836. 1837. 1838. 1839. 1840. 1841. 1842. 1843. C 1844. 1845, seers Manchester . Cambridge.. Newcastle... Bath wee eeneee Birmingham Nottingham Dundee...... Norwich Exeter Liverpool ... Edinburgh . Brighton .:. Oxford ...... Cambridge.. Edinburgh... Dublin Bristol Liverpool... Neweastle... Birmingham Glasgow Plymouth... Manchester. porkca.. vars Cambridge.. Presidents. Rey. W.Whewell, D.D., V.P.RB.S. The Earl of Rosse, M.A., K.P., E.R.S. Rey. B. Price, M.A., F.R.S....... G. B. Airy, M.A., D.C.L., F.R.S. Prof. G. G. Stokes, M.A., F.R.S. Prof. W. J. Macquorn Rankine, C.E., F.RB.S. Prof. Cayley, M.A. F.BS., F.R.AS. W. Spottiswoode, M.A., E.R.S.. F.R.AS. Prof. Wheatstone, D.C.L., F.R.8., Prof, Sir W. Thomson, D.C.L., ...|Prof. J. Tyndall, LL.D., F.B.S... Prof. J. J. Sylvester, LL.D., F.R.S J. Clerk Maxwell, M.A., LL.D., ERS. Prof. P. G. Tait, FR.S.H. i...5 W. Do La Rue, D.C.L., F.RB.S... XXX1 Secretaries. — Rey. 8S. Earnshaw, J. P: Hennessy, Prof. Stevelly, H. J. 8. Smith, Prof. Tyndall. J. P. Hennessy, Prof. Maxwell, H. J.S. Smith, Prof. Stevelly. Rey. G. C. Bell, Rev. T. Rennison, Prof. Stevelly. Prof. R. B. Clifton, Prof. H. J. 8. Smith, Prof. Stevelly. Prof. R. B. Clifton, Prof. H. J.8. Smith, Prof. Stevelly. Rey. N. Ferrers, Prof. Fuller, F. Jen- kin, Prof. Steveliy, Rev. C. T, Whitley. Prof. Fuller, F. Jenkin, Buckle, Prof. Stevelly. Rey. I. N. Hutchinson, I. Jenkin, G. S. Mathews, Prof..H. J. 8. Smith, J. M. Wilson. Fleeming Jenkin, Prof. H. J.8. Smith, Rey. 8S. N. Swann. Rev. G. Buckle, Prof. G. C. Foster, Prof. Fuller, Prof. Swan. Prof. G. C. Foster, Rev. R. Harley, R. B. Hayward. Prof. G. C. Foster, R. B. Hayward, W. K. Clifford. Prof. W. G. Adams, W. K. Clifford, Prof. G. C. Foster, Rev. W. Allen Whitworth. Rey. G. .|Prof. W. G. Adams, J. T. Bottomley, Prof. W. K. Clifford, Prof. J. D. Everett, Rev. R. Harley. Prof. W. K. Clifford, J. W. L. Glaisher, Prof, A. S. Herschel, G. F. Rodwell. CHEMICAL SCIENCE. COMMITTEE OF SCIENCES, II1.— CHEMISTRY, MINERALOGY. Dr. T. Thomson, F.R.S. ...... Rey. Prof. Cumming....... rropecee Michael Faraday, F-.R.S. ......... Rey. William Whewell, I'.R.5.... Prof. T. Graham, F.R:S. ......... {De Sietmas Thothson; F-B.8: +s. Dr. Daubeny, F.R.S, ........06 Prof. Apjohn, M.R.I.A. ...... Prof. T. Graham, F.R.S. ........- John Dalton, D.C.L., F.R.S....... James F. W. Johnston. John Dalton, D.C.L., F.R.S....,..{Prof. Miller. [Dr. Hope..is.ces-sseseesanes sssseeeeee Mr, Johnston, Dx, Christison, SECTION B.—CHEMISTRY AND MINERALOGY. ...|Dr. Apjohn, Prof. Johnston. Dr. Apjohn, Dr. C. Henry, W. Hera- path. Prof. Johnston, Prof. Miller, Dr. Reynolds. Prof. Miller, R. L, Pattinson, Thomas” Richardson. Golding Bird, M.D., Dr. J. B. Melson. Dr. R. D. Thomson, Dr. T. Clark, Dr. L. Playfair. ....J. Prideaux, Robert Hunt, W. M. Tweedy. John Dalton; D.C.L., F.R.S....... ‘Dr. L. Playfair, R. Hunt, J. Graham. ...{R. Hunt, Dr. Sweeny. J. Dr. R. Playfair, B. Solly,T. H. Barker. Rey. Prof. Cumming......... bias .{R. Hunt, J, P. Joule, Prof. Miller, E, Solly. XXXii REPORT—187 2. Date and Place. 1846 1847 1848 1849 1850 1851 1852 1853. 1854. 1855. 1856. 1857. 1858. 1859. 1860, 1861. 1862. 1863. 1864. 1865. 1866 1867 1868, 1869 1870 1871 1832 1833 1834, Edinburgh . Prof, Jameson 1835 1836 1837 ade Southampton Oxford Swansea ... Birmingham Edinburgh . Ipswich Belfast » VXIOrd .,.0.. Liverpool... Glasgow Cheltenham | | | eeeees Aberdeen ... Oxford Manchester .| Cambridge . Newcastle...! Birmingham . Nottingham’ . Dundee . Norwich . Exeter ...... . Liverpool... . Edinburgh . Brighton ... ...|Prof. Thomas Graham, F.R.S.... ...|Dr. Lyon Playfair, C.B., F.R.S.. .../Prof.T, Anderson, M.D., F.R.S.E. .../Prof.E.Frankland, F.R.S., F.C.S8, Presidents. Michael Faraday, D.C.L., F.R.S. Rey.W.V.Harcourt, M.A., F.R.S. Richard Phillips, F.R.S. ......... ‘John Perey, M.D., F.B.S.......... Dr. Christison, V.P.R.S.E. . Thomas Andrews, M.D., F.R.S. . Prof. J. F. W. Johnston, M.A., F.RS. ‘Prof. W. A. Miller, M.D., F.R.S. Prof. B. C. Brodie, F.R.S. Prof. Apjohn, M.D., FE.RBS., M.R.LA. Sir J. F. W. Herschel, Bart., D.C.L. Dr. Lyon Playfair, C.B., F.R.S.. Prof. B. C. Brodie, F.R.S. Prof. W. A. Miller, M.D., F.R.S. Prof. W. A. Miller, M.D., F.R.S. Dr. Alex. W. Williamson, }'.R.S. W. Odling, M.B., F.R.S., F.C.S8. Prof. W. A. Miller, M.D.,V.P.RB.S. H. Bence Jones, M.D., F.R.S.... Dr. H. Debus, F.R.S., F.C.S. ... Prof. H. E. Roscoe, B.A., F.R.S.,) F.C.S. Prof. T. Andrews, M.D., F.R.S. Secretaries, ‘Dr. Miller, R. Hunt, W. Randall. B. C. Brodie, R. Hunt, Prof. Solly. iT. H. Henry, R. Hunt, T. Williams. [R. Hunt, G, Shaw. .. Dr. Anderson, R. Hunt, Dr. Wilson. T. J. Pearsall, W. S. Ward. Dr. Gladstone, Prof. Hodges, Prof. Ronalds. H. 8. Blundell, Prof. R. Hunt, T, J. Pearsall. Dr. Edwards, Dr. Gladstone, Dr. Price. Prof. Frankland, Dr. H. E. Roscoe. J. Horsley, P. J. Worsley, Prof. Voelcker. Dr. Davy, Dr. Gladstone, Prof. Sul- livan. Dr. Gladstone, W. Odling, R. Rey- nolds. J. 8S. Brazier, Dr. Gladstone, G. D. Liveing, Dr. Odling. A. Vernon Harcourt, G. D. Liveing, A. B. Northcote, A. Vernon Harcourt, G. D. Liveing. H. W. Elphinstone, W. Odling, Prof, Roscoe. Prof. Liveing, H. L. Pattinson, J. C. Stevenson, A. V. Harcourt, Prof. Liveing, R. Biggs. A. V. Harcourt, H. Adkins, Prof. Wanklyn, A. Winkler Wills. J. H. Atherton, Prof. Liveing, W. J. Russell, J. White. A. Crum Brown, Prof. G. D. Liveing, W. J. Russell. Dr. A, Crum Brown, Dr. W. J. Rus- sell, F. Sutton. Prof. A. Crum Brown, M.D., Dr. W. J. Russell, Dr. Atkinson, ‘ Prof. A. Crum Brown, M.D., A. B. Fletcher, Dr. W. J. Russell, J. T. Buchanan, W. N. Hartley, T. B. 'Dr. J. H. Gladstone, F.R.S....... | Thorpe. Dr. Mills, W. Chandler Roberts, Dr. | W.J. Russell, Dr. T, Wood. GEOLOGICAL (anv, unrin 1851, GEOGRAPHICAL) SCIENCE. COMMITTEE OF SCIENCES, IJI,—GEOLOGY AND GEOGRAPHY. . Oxford ...... . Cambridge . . Dublin . Bristol . Liverpool... [R. I. Murchison, F.R.S. 'G, B. Greenough, F.R.S. Seeeeeees weeeeee SECTION C.—GEOLOGY AND BR SaGratatiy gy). ..5..8 a aace graphy. R.1, Murchison,F.RB.8. Rey. Prof. Sedgwick, F.R.S.— Geo- graphy. G.B.Greenough, F.R.S, |John Taylor. ..|W. Lonsdale, John Phillips. Prof. Phillips, IT. Jameson Torrie, Rey. J. Yates. GEOGRAPHY. Captain Portlock, T, J. Torrie. William Sanders, 8. Stutchbury, T. J. Torrie. Captain Portlock, R. Hunter.—Geo- graphy, Captain H.M. Denham, R.N. PRESIDENTS AND SECRETARIES OF THE SECTIONS. XXXill i Date and Place. 1838, 1839, 1840 1841 1842, 1845. 1844. 1845. 1846. 1847. 1848. 1849. 1850. 1856. 1857. 1858. 1859. 1860. 1861. 1362. 1863. * At the Meeting of the General Committee subject of Geography be separated from Geolo tute a separate Section, under the title of the for Presidents and Secretaries of which see page Xxxyi. 2 . Ipswich . Hull Presidents. . Newcastle...|C. Lyell, F.R.S., V-P.G.S.— Geo- . Birmingham|Rev. Dr. Buckland, F.R.S.— . Glasgow graphy. Lord Prudhope. Geo- graphy. G.B.Greenough,F.R.S. ...|Charles Lyell, F.R.S.— Geogra- phy. G. B. Greenough, E.R.S. . Plymouth ../H. T. Dela Beche, FBS. . Manchester |R. I. Murchison, F.R.S. ....... seeeeenes Oxford Swansea Edinburgh . Belfast . Liverpool. . . Glasgow Cheltenham Dublin seeeee Manchester Cambridge Neweastle ... Richard HE. Griffith, F.RB.S., M.R.1L.A. Henry Warburton, M.P., Pres. Geol. Soe. Cambridge !.|Rev. Prof. Sedgwick, M.A., F.R.S.|R Southampton|Leonard Horner, F.R.S.— Geogra- phy. G. B. Greenough, F.R.S. Very Rey. Dr. Buckland, F.R.S. E.RS. Birmingham|Sir Charles Lyell, F.R.S., F.G.S.2J. SECTION © (continued).— GEOLOGY. .../William Hopkins, M.A., F.R.S... Lieut.-Col. Portlock, R.E., F.R.S. Prof. Sedgwick, F.R.S. .........++- Prof. Edward Forbes, F.R.S. ... ...(Sir RB. I. Murchison, F.R.S. ...... Prof. A. C. Ramsay, F.R.S. ...... The Lord Talbot de Malahide ... William Hopkins, M.A., LL.D., E.R.S. Sir Charles Lyell, LL.D., D.C.L., F.R.S. Rey. Prof. Sedgwick, LL.D., F.RS., F.G:8. D.C.L., Sir R. I. Murchison, J. Beete Jukes, M.A., F.R.S....... LLD., F.BS., &e. Prof. -Warington W. Smyth, E.RBS., F.G.8. sey Secretaries. W. C. Trevelyan, Capt. Portlock.— Geography. Capt. Washington. George Lloyd, M.D.,H. E. Strickland, Charles Darwin. W. J. Hamilton, D. Milne, Hugh Murray, H. E. Strickland, John Scoular, M.D W.J. Hamilton, R. Hutton. “Eaward Moore,M.D., .|E. W. Binney, R. Hutton, Dr. R. Lloyd, H. E. Strickland. Francis M. Jennings, H. E. Strick- land. Prof. Ansted, E. H. Bunbury. ev. J. C. Cumming, A. C. Ramsay, Rev. W. Thorp. Robert A. Austen, J. H. Norten, M.D., Prof. Oldham.— Geography. Dr. C. T. Beke. Prof. Ansted, Prof. Oldham, A. C. Ramsay, J. Ruskin. ...(Sir H. T. De la Beche, C.B.,|Starling Benson, Prof, Oldham, Prof. Ramsay. Beete Jukes, Prof. Oldham, Prof. A. C. Ramsay. *|Siy RoderickI. Murchison,F.R.S.|A. Keith Johnston, Hugh Miller, Pro- fessor Nicol. C.J. F. Bunbury, G. W. Ormerod, Searles Wood. James Bryce, James MacAdam, Prof. M‘Coy, Prof. Nicol. Prof. Harkness, William Lawton. John Cunningham, Prof. Harkness, G. W. Ormerod, J. W. Woodall. James Bryce, Prof. Harkness, Prof. Nicol. Rev. P. B. Brodie, Rev. R. Hepworth, Bdward Hull, J. Scougall, T. Wright. Prof. Harkness, Gilbert Sanders, Ro- bert H. Scott. Prof. Nicol, H. C. Sorby, E. W. Shaw. Prof. Harkness, Rey. J. Longmuir, H. C. Sorby. Prof. Harkness, Edward Hull, Capt. Woodall. Prof. Harkness, Edward Hull, T. Ru- pert Jones, G. W. Ormerod. Lucas Barrett, Prof. T. Rupert Jones, H. C. Sorby. E. F. Boyd, John Daglish, H. C. Sor- by, Thomas Sopwith. ; held in Edinburgh, it was agreed “That the gy and combined with Ethnology, to consti- “Geographical and Etbnological Section,” ¢ XXXIV REPORT—1872. i ee Date and Place. : Presidents. Secretaries. 1864, Bath ...... Prof. J. Phillips, LL.D., F.B.S., W. B. Dawkins, J. J ohnston, H. C. G.S Sorby, W. Pengelly. 1865. Birmingham|Sir R. I. Murchison, Bart.,K.C.B.|Rey. P. B. Brodie, J. Jones, Rey. E. Myers, H. C. Sorby, W. Pengelly. 1866. Nottingham Prof.A.C. Ramsay, LL.D., F.R.S./R. Etheridge, W. Pengelly, T. Wil- son, G. H. Wright. 1867. Dundee...... Archibald Geikie, F.R.S., F.G.S.|Edward Hull, W. Pengelly, Henry Woodward. T 1868. Norwich ...\R. A. C. Godwin-Austen, F.R.S.,/Rev. O. Fisher, Rev. J. Gunn, W. E.G.S. Pengelly, Rey. H. H. Winwood. 1869. Exeter ...... Prof, R. Harkness, F.R.S., F.G.8./W. Pengelly, W. Boyd Dawkins, Rey. H. H. Winwood. 1870. Liverpool.../Sir Philip de M. Grey Egerton, W. Pengelly, Rev. H. H. Winwood, Bart., M.P., F.RB.S. W. Boyd Dawkins, G. H. Morton. 1871. Edinburgh ..|Prof. A. Geikie, F.R.S., F.G.S.../R. Etheridge, J. Geikie, J. MceKenny Hughes, L. C. Miall. 1872. Brighton .../R. A. C. Godwin-Austen, F.R.S.|L. C. Miall, George Scott, William ; Topley, Henry Woodward. BIOLOGICAL SCIENCES. ; COMMITTEE OF SCIENCES, IV.—-ZOOLOGY, BOTANY, PHYSIOLOGY, ANATOMY. 1832. Oxford ...... Rey. P. B. Duncan, F.G.S. ......Rev. Prof. J. 8. Henslow. 1833. Cambridge */Rey. W. L. P. Garnons, F.LS....|C. C. Babington, D. Don. 1834, Edinburgh |Prof. Graham...........cccsseeeseees W. Yarrell, Prof. Burnett. SECTION D.—ZOOLOGY AND BOTANY. 1835. Dublin ...... Dre AMIITAT ccmcecttaicarsns seg sSehes2% J. Curtis, Dr. Litton. 1836. Bristol ...... Rey. Prof. Henslow .........0+00.- J. Curtis, Prof. Don, Dr. Riley, -S. Rootsey. 1837. Liverpool ...JW. S. MacLeay .........cccsesseeeee C. C. Babington, Rey. L. Jenyns, W. Swainson. 1838. Newcastle...|Sir W. Jardine, Bart......... wss...{J- B. Gray, Prof. Jones, R. Owen, Dr. Richardson. 1839. Brimingham|Prof. Owen, F.R.S. ......ceeeeeees E. Forbes, W. Ick, R. Patterson. 1840. Glasgow ...|Sir W. J. Hooker, LL.D .......... Prof. W. Couper, E. Forbes, R. Pat- terson. 1841, Plymouth...\John Richardson, M.D., F-R.S...|J. Couch, Dr. Lankester, R. Patterson. 1842. Manchester |Hon. and Very Rey. W. Herbert,|Dr. Lankester, R. Patterson, J. A. DBs: Turner. 1843. Cork .......:. William Thompson, F.L.§, ......{G. J. Allman, Dr. Lankester, R. Pat- terson. 1844, York...,..... Very Rey. The Dean of Manches-|Prof. Allman, H. Goodsir, Dr. King, ter. Dr. Lankester. 1845. Cambridge |Rev. Prof. Henslow, F.LS. ....../Dr. Lankester, T. V. Wollaston. 1846. Southampton|Sir J. Richardson, M.D., F.R.S. |Dr. Lankester, T. V. Wollaston, H. Wooldridge. 1847. Oxford....... H. E. Strickland, M.A., F.R.S....|Dr. Lankester, Dr. Melville, T. V. Wollaston. SECTION D (continued).—ZOOLOGY AND BOTANY, INCLUDING PHYSIOLOGY. [For the Presidents and Secretaries of the Anatomical and Physiological Subsections and the temporary Section E of Anatomy and Medicine, see pp. xxxvi.] 1848. Swansea ...)L. W. Dillwyn, F.R.S. ............ Dr. R, Wilbraham Falconer, A. Hen- “diggs frey, Dr. Lankester. 1849. Birmingham] William Spence, F.R.S.........-..- Dr. Lankester, Dr. Russell. 1850. Edinburgh. .|Prof. Goodsir, F.R.S. L. & E. ...!Prof. J. H. Bennett, M.D., Dr. Lan- kester, Dr. Douglas Maclagan. * At this Meeting Physiology and Anatomy were made a separate Committee, for Presidents and Secretaries of which see p. Xxxy. PRESIDENTS AND SECRETARIES OF THE SECTIONS. XXXV Date and Place. 1851. 1869. 1870, 1871 . Hull Ipswich Belfast . Manchester.. . Cambridge... . Newcastle ... . Nottingham. Liverpool... . Hdinburgh . Liverpool ... . Glasgow . Cheltenham. teens beeen eeee eee : aaa Thomson, M.D., F.R.S8. Presidents. Rey. Prof. Henslow, M.A., F.R.8. W. Ogilby C. C. Babington, M.A., F.RB.S.... Prof. Balfour, M.D., F.R.S....... — Sete meee eee ee tees eee eaeeee ...|Rev. Dr. Fleeming, F.R.S.E. ... Thomas Bell, F.R.S., Pres.L.S.... Prof. W.H. Harvey, M.D., F.R.S. C. C. Babington, M.A., F.R.5.... Sir W. Jardine, Bart., F.R.8.E.. Rey. Prof. Henslow, F.LS. ...... Prof. C. C. Babington, F.R.S.... Prof. Huxley, F.B.S. .........s Prof. Balfour, M.D., F.RB.8....... Dr. John E. Gray, F.R.S8. eannee Secretaries. ey Prof. Allman, F. W. Johnston, Dr. E. Lankester. Dr. Dickie, George C. Hyndman, Dr Edwin Lankester. Robert Harrison, Dr. E. Lankester, Isaac Byerley, Dr. E. Lankester. William Keddie, Dr. Lankester. Dr. J. Abercrombie, Prof. Buckman, Dr. Lankester. Prof. J. R. Kinahan, Dr. E. Lankester, Robert Patterson, Dr. W. E. Steele. Henry Denny, Dr. Heaton, Dr. E. Lankester, Dr. E. Perceval Wright. Prof. Dickie, M.D., Dr. E. Lankester, Dr. Ogilvy. W.S. Church, Dr. E. Lankester, P. L. Sclater, Dr. E. Perceval Wright- Dr. T. Alcock, Dr. E. Lankester, Dr. P. L. Sclater, Dr. KE. P. Wright. Alfred Newton, Dr. E. P. Wright. Dr. E. Charlton, A. Newton, Rev. H. B. Tristram, Dr. HE. P. Wright. H. B. Brady; C. E. Broom, H. T. Stainton, Dr. E. P. Wright. Dry. J. Anthony, Rey. C. Clarke, Rev. H. B. Tristram, Dr. E. P. Wright, SECTION D (continued).—BIOLOGY *. Prof. Huxley, LL.D., F.R.S.— Physiological Dep. Prof. Hum- phry, M.D., F.R.S.—Anthropo- logical Dep. Alfred R. Wallace, E.R.G:S. Prof. Sharpey, M.D., Sec. R.S.— Dep. of Zool. and Bot. George Busk, M.D., F.R.S. ...|Rev. M. J. Berkeley, F.L.S.— Dep. of Physiology. W. H. Flower, F.R.S. Bate, F.R.S.—Dep. of Ethno. H. B. Tylor. Prof. G. Rolleston, M.A., M.D., E.R.S., F.L.S.—Dep. Anat. and Physio. Prof. M. Foster, M.D., F.LS—Dep. of Ethno. Evans, F.R.S. Prof. Allen Thomson,M.D.,F.R.S. —Dep. of Bot. and Zool.. Prof. Wyville Thomson, F.R.S.— Dep. of Anthropo. Prof. W. Turner, 1872. Brighton .,.\Sir John Lubbock, Bart., F.R.S. —Dep. of Anat. and Physio. Dr. Burdon Sanderson, F.R.S. —Dep of Anthropo, Col. A. Lane Fox, F.G.S. George Busk, F.R.S., F.L.S.— Dep. of Bot. and Zool. C. Spence J. Dr. J. Beddard, W. Feikin, Rev: H. B. Tristram, W. Turner, E. B. Tylor, Dr. E, P. Wright. C. Spence Bate, Dr. 8. Cobbold, Dr, M. Foster, H. T. Stainton, Rey. H, B. Tristram, Prof. W. Turner. Dr. T. 8. Cobbold, G. W. Firth, Dr. M. Foster, Prof. Lawson, H. T, Stainton, Rev. Dr. H. B. Tristram, Dr. E. P. Wright. Dr. T. S. Cobbold, Prof. M. Foster, M.D., E. Ray Lankester, Professor Lawson, H. T’. Stainton, Rey, H. B. Tristram. * Dr. T. 8. Cobbold, Sebastisn Evans, Prof. Lawson, Thos. J. Moore, H T. Stainton, Rey. H. B. Tristram, C. Staniland Wake, EH. Ray Lan- kester. Dr. T. R. Fraser, Dr. Arthur Gamgee, E. Ray Lankester, Prof. Lawson, Hi. T. Stainton, C. Staniland Wake, Dr. W. Rutherford, Dr. Kelburne King. Prof. Thiselton-Dyer, H. T. Stainton, Prof. Lawson, F. W. Rudler, J. H. Lamprey, Dr. Gamgee, E. Ray Lan- kester, Dr. Pye Smith. * At the Meeting of the General Committee at Birmingham, it was resolved :—“ That the title of Section D be changed to Biology ;” and “That for the word ‘Subsection,’ in the rules for conducting the business of the Sections, the word ‘ Department’ be substituted, ¢2 XXXVI Date and Place. REPORT—1872. Presidents. Secretaries. ANATOMICAL AND PHYSIOLOGICAL SCIENCES. COMMITTEE OF SCIENCES, V.—ANATOMY AND PHYSIOLOGY. 1833. Cambridge... 1834. Edinburgh... MDF Haviland iasyns sree castacke reese Dr. Abercrombie Coenen teeter eenene Dr. Bond, Mr. Paget. Dr, Roget, Dr. William Thomson. SECTION E, (UNTIL 1847.)—ANATOMY AND MEDICINE. 1835. Dublin 1836. Bristol eeenes Dy peritchard. Wes. eccsasceresecsse Dr. Roget, FLR.S. ....ceseees possane 1837, Liverpool ...|Prof. W. Clark, M.D. ........... 1838. Newcastle ...|T. E. Headlam, M.D. ............ 1839. Birmingham|John Yelloly, M.D., F.R.S. ...... 1840. Glasgow ...\James Watson, M.D.............--- 1841. Plymouth.../P. M. Roget, M.D., Sec.R.S. 1842. Manchester.|Edward Holme, M.D., F.LS. ... 1843. Cork 1844. York 1846. Southampton Prof, Owen, M.D., F.R.S Sir James Pitcairn, M.D.......... J. C. Pritchard, M.D. ........... Dr. Harrison, Dr. Hart. Dr. Symonds. Dr. J. Carson, jun., James Long, Dr. J. R. W. Vose. T. M. Greenhow, Dr. J. R. W. Vose. Dr. G. O. Rees, F. Ryland. Dr. J. Brown, Prot. Couper, Prof. Reid. ...!Dr. J. Butter, J. Fuge, Dr. R. 8. Sargent. Dr. Chaytor, Dr. R. S. Sargent. Dr. John Popham, Dr. R. 8. Sargent. I. Erichsen, Dr. R. 8. Sargent. . SECTION E,— PHYSIOLOGY. 1845. Cambridge .!Prof. J. Haviland, M.D. ......... Dr. R. 8. Sargent, Dr. Webster. C. P. Keele, Dr. Laycock, Dr. Sargent. 1847. Oxford* ae Ogle, M.D., B.R.S.'......... Dr. Thomas K. Chambers, W. P: 1850, 1855. 1857. 1858. 1859. 1860. 1861. 1862. Edinburgh Glasgow Dublin Leeds Oxford ...... Manchester. Cambridge . 1863. Newcastle... 1864. Bath........ ...|Prof. Allen Thomson, F.R.S. PHYSIOLOGICAL SUBSECTIONS Prof. Bennett, M.D., F.R.S.E. Prof. R. Harrison, M.D. ......... Sir Benjamin Brodie, Bart..F.R.S. Prof. Sharpey, M.D., Sec.R.S. ... Prof. G. Rolleston, M.D., F.L.S. Dr. John Davy, F.R.S.L. & E.... Gos, Pagel MSD on. comes naecsstss Prof. Rolleston, M.D., F.R.S. ... Dr. Edward Smith, LL.D., F 1865, Birminghmf. “RS. Prof. Acland, M.D., LL.D., F.R.S. Ormerod. OF sEcTION D. ...|Prof. J. H. Corbett, Dr. J. Struthers. Dr. R. D. Lyons, Prof. Redfern. C. G. Wheelhouse. : Prof. Bennett, Prof. Redfern. Dr. R. M‘Donnell, Dr. Edward Smith. Dr. W. Roberts, Dr. Edward Smith. G. F. Helm, Dr. Edward Smith. Dr. D. Embleton, Dy. W. Turner. J. 8S. Bartrum, Dr. W. Turner. Dr. A. Fleming, Dr. P. Heslop, Oliver Pembleton, Dr. W. Turner, GEOGRAPHICAL AND ETHNOLOGICAL SCIENCES. [For Presidents and Secretaries for Geography previous to 1851, see Section C, p. xxxii.] 1846.Southampton|Dr. Pritchard 1847. Oxford... 1848. Swansea ETHNOLOGICAL SUBSECTIONS ONO e beeen rea ee enone ...|Prof, H. H. Wilson, M.A. seeeee OF srction D. Dr. King. Prof. Buckley. G. Grant Francis. Dr. R. G. Latham. ..-|/Daniel Wilson. * By direction of the General Committee at Oxford, Sections D and E were incorporated under the name of “Section D —Zoology and Botany, including Physiology” (sec-p. xxxiv). The Section being then vacant was assigned in 1851 to Geography. t Vide note on preceding page. PRESIDENTS AND SECRETARIES OF THE SECTIONS, | XXXvil i Date and Place. Presidents. Secretaries. . Ipswich . Belfast 1854. eartegoal. ‘ 1855 1856 -1857 -1858. . Glasgow ... . Cheltenham 1859. Aberdeen ... 1860. Oxford 1861. 1862 -1863. Newcastle... 1864. Manchester. . Cambridge . Pee nenees 1865. Birmingham| 1866, Nottingham ~ 1867. Dundee seenee SECTION E.—GEOGRAPHY AND ETHNOLOGY. ...|Sir R. I. Murchison, F.R.S., Pres. R.G.S Col. Chesney, R.A., D.C.L., R. G. Latham, M.D., F.R.S. Sir R. I. Murchison, D.C.L., F RS. ‘Sir J. Richardson, M.D., F.R.S8. Col. Sir H. C. Rawlinson, K.C.B. Rey. Dr. J. Henthawn Todd, Pres. R.A. Sir R. I. Murchison, G.C.St.8., E.R.S. Rear-Admiral Sir. James Clerk Ross, D.C.L., F.R.S. Sir R. I. Murchison, D.C.L., FE.R.S. John Crawfurd, F.RB.S..........0.. Francis Galton, F.R.S. ...........- Sir R. I. Murchison, K.C.B., EBS. Sir R. I. Murchison,. K.C.B., E.RB.S. Major-General Sir R. Rawlinson, R. Cull, Rev. J. W. Donaldson, Dr. Norton Shaw. R. Cull, R. MacAdam, Dr. Norton Shaw. .../R. Cull, Rev. H. W. Kemp, Dr. Nor- ton Shaw. Richard Cull, Rev. H. Higgins, Dr. Ihne, Dr. Norton Shaw. Dr. W. G. Blackie, R. Cull, Dr. Nor- ton Shaw. R. Cull, F. D. Hartland, W. H. Rum- sey, Dr. Norton Shaw. R. Cull, S. Ferguson, Dr. R. R. Mad- den, Dr. Norton Shaw. R. Cull, Francis Galton, P. O’Cal- laghan, Dr. Norton Shaw, Thomas Wright. Richard Cull, Professor Geddes, Dr. Norton Shaw. Capt. Burrows, Dr. J. Hunt, Dr. C. Lempriere, Dr. Norton Shaw. Dr. J. Hunt, J. Kingsley, Dr. Norton Shaw, W. Spottiswoode. J. W. Clarke, Rev. J. Glover, Dr. Hunt, Dr. Norton Shaw, T. Wright. C. Carter Blake, Hume Greenfield, C. R. Markham, R. 8S. Watson. H. W. Bates, C. R. Markham, Capt. R. M. Murchison, T. Wright. H. W. Bates, S. Evans, G. Jabet, C. M.P., K.C.B., F.B.S. Sir Charles Nicholson, Bart., LL.D. Sir Samuel Baker, F.R.G.S. : a * 1858. Norwich ©... 1869. Exeter ‘1870. Liverpool... 1871. Edinburgh. Colonel Yule, C.B., F.R.G.S. . 1872. Brighton . 1833. Cambridge . - 1834, Edinburgh . 1835. Dublin 1836. Bristol. wanes Capt. G. H. Richards, R.N., tay R. Markham, Thomas Wright. H. W. Bates, Rev. E. T. Cusins, R. H. Major, Clements R. Markham, D. W. Nash, T. Wright. . ...(H. W. Bates, Cyril Graham, C. R. Markham, 8. J. Mackie, R. Sturrock, Baines, H. W. Bates, C. R. Mark- ham, T. Wright. SECTION E (continued).— GEOGRAPHY. Sir Bartle Frere, K.C.B., F.R.G.S. LL.D., D.C.L., F.RB.S., F.G.S. LL.D.,|H. W. Bates, Clements R. Markham, J. H. Thomas. |Sir BR, I. Murchison, Bt-, K.C.B.,|H. W. Bates, David Buxton, Albert J. Mott, Clements R. Markham. ..|Clements R. Markham, A. Buchan, J. H. Thomas, A. Keith Johnston. ..|Francis Galton, F.R.S. ..........- H. W. Bates, A. Keith Johnston, Rey. J. Newton, J. H. Thomas. STATISTICAL SCIENCE. COMMITTEE OF SCIENCES, VI Prof. Babbage, F.R.8. .. Sir Charles Lemon, Bart. ........- .— STATISTICS, J. E. Drinkwater. Dr, Cleland, C. Hope Maclean. SECTION F.—STATISTICS. Charles Babbage, F.R.S. ... seeeee Sir Charles Lemon, Bart., F.R.S. W. Greg, Prof. Longfield. : Rev. J. E. Bromby, C. B, Fripp, James Heywood. 1851. Ipswich...... 1852. Belfast 1853. Hull ......... 1854. Liverpool .. 1855, Glasgow Sir John P. Boileau, Bart. Dublin. «++«.{R. Monckton Milnes, M.P. ... SECTION F (continued).—ECONOMIC 1856. Cheltenham |Rt. Hon. Lord Stanley, M.P. 1857. Dublin Dublin, M.R.1.A 1858. Leeds........|Edward Baines ......cccssccssseees 1859. Aberdeen ...|Col. Sykes, M.P., F.R.S. ..... 1860. Oxford ...... Nassau W. Senior, M.A.......... 1861. Manchester |William Newmarch, F.R.S. ... 1862. 1863. Newcastle ...|William Tite, M.P., F.R.S. .... HS642"Bath, ..ccceces pe Farr, M.D., D.C.L., E.RS. 1865. Birmingham|Rt. Hon. Lord Stanley, LU.D., M.P. 1866, 1867. Dundee...... 1868. Norwich M. E. Grant Duff, M.P. tuaries, hones James Heywood, M.P., F.R.S.... .|Dhomas Tooke, F.R.S. ........06. His Grace the Archbishop of Cambridge. ./Edwin Chadwick, C.B. ........... Nottingham |Prof. J. H. T. Rogers... ... Samuel Brown, Pres. Instit. Ac- ‘XxXxviil REPORT—1872. Date and Place. Presidents. Secretaries. 1837. Liverpool... Rt. Hon. Lord Sandon ............ W. R. Greg, W. Langton, Dr. W. C. Tayler. .1838. Newcastle...|Colonel Sykes, F.R.S. ..cccceeeeee W. Cos gill, J. Heywood, W. R. Wood. 1839. Birmingham|Henry Hallam, F\RB.S. ............ F. Clarke, R. W. Rawson, Dr. W. C. Tayler. 1840. Glasgow .../Rt. Hon. Lord Sandon, F-.R.S.,\C. R Baird, Prof. Ramsay, R. W. M.P. Rawson. 1841. Plymouth... Lieut.-Col. Sykes, F.R.S. .......0: Rey. Dr. Byrth, Rey. R. Luney, R. W. Rawson. 1842. Manchester .|G. W. Wood, M.P., F.L.S. ...... Rev. R. Luney, G. W. Ormerod, Dr. W. C. Tayler. 1843. Cork......... Sir C. Lemon, Bart., M.P. ....../Dr. D. Bullen, Dr. W. Cooke Tayler. 1844. York......... Lieut.-Col. Sykes, F.R.S., F.L.S. |J. Fletcher, J. Heywood, Dr. Laycock. 1845. Cambridge ./Rt. Hon. The Earl Fitzwilliam.. .|J. Fletcher, W. Cooke Tayler, LL.D. 1846.Southampton|G. R. Porter, F.R.S. ..........c.0: J. Fletcher, F. G. P. Neison, Dr. W. C. Tayler, Rey. T. L. Shapcott. 1847. Oxford ...... Travers Twiss, D.C.L., F.R.S..../Rev. W. H. Cox, J. J. Danson, F. G. P. Neison. 1848. Swansea ...|J. H. Vivian, M.P., F.R.S. ....../J. Fletcher, Capt. R. Shortrede 1849. Birmingham|Rt. Hon. Lord Lyttelton ......... Dr. Finch, Prof. Hancock, F. G. P. Neison. 1850. Edinburgh ../Very Rey. Dr. John Lee, /|Prof. Hancock, J. Fletcher, Dr. V.P.R.S.E. Stark. .J. Fletcher, Prof. Hancock. His Grace the Archbishop of Prof. Hancock, Prof. Ingram, James MacAdam, Jun. Edward Cheshire, William Newmarch. .|E. Cheshire, J. T. Danson, Dr. W. H. Duncan, W. Newmarch. ...\J. A. Campbell, E. Cheshire, W. New- march, Prof, R. H. Walsh. SCIENCE AND STATISTICS, ....Rev. C. H. Bromby, E. Cheshire, Dr. W. N, Hancock Newmarch, W. M. ~ Tartt. Prof. Cairns, Dr. H. D. Hutton, W. Newmarch, ./T. B. Baines, Prof. Cairns, 8. Brown, Capt. Fishbourne, Dr. J. Strang. ..../Prof. Cairns, Edmund Macrory, A.M. Smith, Dr. John Strang. .|.Edmund Macrory, W. Newmarch, Rey. Prof. J. E. T. Rogers. ...|David Chadwick, Prof. R. C. Christie, BE. Macrory, Rev. Prof. J. EH. T Rogers. .|H. D. Macleod, Edmund Macrory. ..|T. Doubleday, ‘Edmund Macrory, Frederick Purdy, James Potts. EH. Macrory, EH. T. Payne, F. Purdy. G. J. D. Goodman, G. J. Johnston, E. Macrory. R. Birkin, Jun., Prof. Leone Leyi, E. Macrory. .|Prof. Leone Levi, E. Macrory, A. J. Warden. piers W. C, Davie, Prof. Leone Levi. PRESIDENTS AND SECRETARIES OF THE SECTIONS: XXXIX EE i ee Date and Place. Secretaries. Presidents. Rt. Hon. Sir Stafford H. North-/Edmund Macrory, Frederick Purdy, cote, Bart., C.B., M.P. Charles T. D. Acland. 1870. Liverpool...|Prof. W. Stanley Jevons, M.A... Chas. R. Dudley Baxter, E, Macrory, J. Miles Moss. Mowaswecsdene J. G. Fitch, James Meikle. ...|J. G. Fitch, Barclay Phillips, 1869. Exeter eeenee 1871. Edinburgh [Rt. Hon. Lord Neaves 1872. Brighton .../Prof, Henry Fawcett, M.P. ... MECHANICAL SCIENCE. SECTION G,—-MECHANICAL SCIENCE. 1836. Bristol ...... 1837. Liverpool ... 1838. Newcastle ... 1839. Birmingham 1840. Glasgow .. 1841. Plymouth... 1842. Manchester . 1843. Cork 1844. York 1845. Cambridge .. 1846, Southampton 1847. Oxford 1848. Swansea 1849. Birmingham 1850. Edinburgh .. 1851. Ipswich 1852, Belfast 1853, Hull ...... es 1854. Liverpool ... 1855. Glasgow ... 1856. Cheltenham teeeee (Sir John Robinson Davies Gilbert, D.C.L., F.R.S.... Rey. Dr. Robinson Charles Babbage, F'.R.S...... Prof, Willis, F.R.S Stephenson. abet een ene eeeeeees teeter COR eeweoeeee John Taylor, F.R.S. ..sceseeseeeees Rey. Prof. Willis, F.R.S. ......... Prof. J. Macneill, M.R.LA....... John Taylor, F.R.S. .sccceeeeeees George Rennie, F.R.S. ........+.-- Rey. Prof. Willis, M.A., F.R.S. . Rev. Prof. Walker, M.A., F.R.S. Rey. Prof. Walker, M.A., F.R.S. Robert Stephenson, M.P., F.R.S. Rey. Dr. Robinson William Cubitt, F.R.S............. John Walker,C.E., LL.D., F.R.S. weet ee tetenenes William Fairbairn, C.E., F.R.S.. John Scott Russell, F.R.S. ...... W. J. Macquorn Rankine, C.E., E.RB.S. George Rennie, F.R.S. ......+. iat . and Robert T. G. Bunt, G. T. Clark, W. West. Charles Vignoles, Thomas Webster. ..|R. Hawthorn, C. Vignoles, T. Webster. W. Carpmael, William Hawkes, Tho- mas Webster. J. Scott Russell, J, Thomson, J. Tod, C. Vignoles. Henry Chatfield, Thomas Webster. J. F. Bateman, J. Scott Russell, J. Thomson, Charles Vignoles. James Thomson, Robert Mallet. Charles Vignoles, Thomas Webster. Rey. W. T. Kingsley. William Betts, Jun., Charles Manby. J. Glynn, R. A. Le Mesurier. R. A. Le Mesurier, W. P. Struvé. Charles Manby, W. P. Marshall. Dr. Lees, David Stephenson. John Head, Charles Manby. John F. Bateman, C. B. Hancock, Charles Manby, James Thomson. James Oldham, J. Thomson, W. Sykes Ward. John Grantham, J. Oldham, J, Thom~- son. L. Hill, Jun., William Ramsay, J. Thomson. C. Atherton, B. Jones, Jun., H. M. Jeffery. 1857. Dublin ...... The Right Hon. The Earl of|Prof. Downing, W.'T. Doyne, A. Tate, Rosse, F.R.S. James Thomson, Henry Wright. 1858. Leeds......... William Fairbairn, F.R.S. ......\3. C. Dennis, J. Dixon, H. Wright. 1859. Aberdeen ...\Rev. Prof. Willis, M.A., F.R.S. .|R. operate P. Le Neve Foster, H. ; right. 1860. Oxford ...... Prof. W. J. Macquorn Rankine,|P. Le Neve Foster, Rey. F. Harrison, LL.D., F.B.S. Henry Wright. 1861. Manchester . 1862. Cambridge .. 1863. Newcastle... 1864. Bath 1865. Birmingham 1866. Nottingham 1867. Dundee 1868. Norwich ...\&. P, Bidder, J. F. Bateman, C.E., F.RB.S....... William Fairbairn, LL.D., F.R.S. Rey. Prof. Willis, M.A., F.RB.S. . J. Hawkshaw, F.R.S. Sir W. G. Armstrong, F.R.S. Thomas C.H., F.G.8. Prof. W. J. Macquorn Rankine, LLD., FBS. C.E., FR.GS. - Hawksley, § P. Le Neve Foster, John Robinson, H. Wright. W. M. Faweett, P. Le Neve Foster. P. Le Neve Foster, P. Westmacott, J. F. Spencer. A. Tarbottom. P. Le Neve Foster, John P. Smith, W. W. Urquhart. P. Le Neve Foster, J. F. Iselin, C. Manby, W. Smith. x] REPORT—1872. Date of Place. 1869. Exeter 1870. Liverpool... 1871. Edinburgh |Prof. Fleeming Jenkin, F.R.S... 1872. Brighton .. |B. J. Bramwell, C.E........ Presidents. Secretaries. C. W. Siemens, F.R.S. ............ P. Le Neve Foster, H. Bauerman. .|Chas. B. Vignoles, C.E., F.R.S. .|H. Bauerman, P. Le Neve Foster, T. King, J. N. Shoolbred. .|H. Bauerman, Alexander Leslie, J. P, Smith. H. M. Brunel, P. Le Neve Foster, J. G, Gamble, J. N. Shoolbred. List of Evening Lectures. Date and Place. 1842, Manchester . 1843. Cork 1844. York 1845. Cambridge .. 1846. Southampton 1847. Oxford wanes 1848. Swansca 1849. Birmingham 1850, Edinburgh. 1851. Ipswich..... 1852. Belfast .| John Percy, M.D., F.RB.S. seen eeeee 1853, Hull 1854, Liverpool .., Lecturer. Charles Vignoles, F.R.S.......06 Sir M. I. Brunel SR spep ECC IARON tea aare es asic oe’ Prof. Owen, M.D., F.R.S. ...... Prof. E. Forbes, F.R.S. .. eee rere eee DD) eMRODINSOM. jscuvanecs cesses sesens Charles Lyell, F.R.S. .........00+ Dr sHalconer) HAR Ss. cosscecesse G. B. Airy, F.R.S., Astron. aha R. I. Murchison, FB. R.S Prof. Owen, M.D., F.R. S. Charles Lyell, ERS. ca Rel W. R. Grove, F.B.8. Rey. Prof. B. Powell, F.R.S. . Prof. M. Faraday, F.R.8. Hugh £. Strickland, F.G.S. W. Carpenter, M.D,, F.R.S. .. Dr) Maradayeeh RuSrcmsereescnscens Rey. Prof. Willis, M.A., F.R.S. Prof. J. H. Bennett, M.D., E.R.S.E. Dr. Mantell, F.R.8.. BO .| Prof. R. Owen, MD. ‘FRS. G. B. Airy, F.R.S., Astron. Roy. Prof. G.G. Stokes, D.C.L., F.R.S. Colonel Portlock, R.E., F.R.S. Prof. J. Phillips, LL.D., F.R.S., F.G.S. Robert Hunt, F.R.S. .........4.. Subject of Discourse. The Principles and Construction of Atmospheric Railways. The Thames Tunnel. The Geology of Russia. The Dinornis of New Zealand. The Distribution of Animal Life in the Afgean Sea. The Earl of Rosse’s Telescope. Geology of North America. The Gigantic Tortoise of the Siwalik Hills in India. Progress of Terrestrial Magnetism. Geology of Russia. .| Fossil Mammalia of the British Isles. ..| Valley and Delta of the Mississippi. Properties of the Explosive substance discovered by Dr. Schénbein ; also some Researches of his own on the Decomposition of Water by Heat. .| Shooting-stars, Magnetic and Diamagnetic Pheno- mena. ...| The Dodo (Didus ineptus).3 ...| Metallurgical operations of Swansea and its neighbourhood. ...| Recent Microscopical Discoveries. Mr. Gassiot’s Battery. Transit of different Weights with varying velocities on Railways. Prof. R. Owen, M.D., F.R.S.. Col. EH, Sabine, V.P. R. iS Ree e oe et Passage of the Blood through the minute vessels of Animals in con- nexion with Nutrition. Extinct Birds of New Zealand, Distinction between Plants and Ani- mals, and their changes of Form. Total Solar Ielipse of July 28, 1851. Recent discoveries in the properties of Light. Raocnk, discovery of Rock-salt at Car- rickfergus, and geological and prac- tical considerations connected with it. Some peculiar phenomena in the Geo- logy and Physical Geography of Yorkshire. The present state of Photography. .| Anthropomorphous Apes. Progress of researches in Terrestrial Magnetism. LIST OF EVENING LECTURES. xli ——— eee Date and Place. ——— 1855. Glasgow 1856, Cheltenham 1857. Dublin ...... 1858. Leeds 1859. Aberdeen .. 1860. Oxford ...... 1861. Manchester . 1862, Cambridge . 1863. Newcastle- on-Tyne. 1864. Bath eee eeeee 1865. Birmingham 1866. Nottingham. 1867. Dundee 1868. Norwich .... 1869. Exeter ..... 1870. Liverpool ... 1871. Edinburgh 1872. Brighton ... Lecturer. Dr. W. B. Carpenter, F'.R.S. ... Lieut.-Col. H. Rawlinson seeeee Col. Sir H, Rawlinson ............ W. RB. Grove, F.R.S. ....0+000 Prof. W. Thomson, F’.R.S. ...... Rey. Dr. Livingstone, D.C.L. ... Prof. J. Phillips, LL.D., F. B.S. Prof. R. Owen, M.D., F.R.S... Rey. Dr. Robinson, F.R.S. ...... Rev. Prof. Walker, F.R.S. ...... Captain Sherard Osborn, R.N. . Prof. W. A. Miller, M.A., F.R.S. G. B. Airy, F.R.S., Astron. Roy. . Prof. Tyndall, LL.D., F.R.S. ... Prof. Odling, F.R.S.......08...... Prof. Williamson, F.R.8. aeeeee James Glaisher, F.R.S. ee eewenes Prof. Roscoe, F.R.S........00ce0ee Dr. Livingstone, F.R.S. ......... J. Beete Jukes, F.R.S............- William Huggins, F.R.S. seneeeeee Dr. J. D. Hooker, F.R.S.......... Archibald Geikie, F.R.S.......... Alexander Herschel, F.R.A.S. ... J. Fergusson, F.R.S. Dr. W. Odling, F.R.S. ........... .| Prof. J. Phillips, LL.D., F.R.S. J. Norman Lockyer, F.RB.S....... Prof. J. Tyndall, LL.D., F.R.S8. Prof. W. J. Macquorn Rankine, LL.D., F.R.S. CAL, Albel He Rncitese. .cneeesernacs EB. Wylor, HARISs sccnsscancce ss Prof. P. Martin Duncan, M.D., F.R.S. Prof. W. K. Clifford......s0+ Subject of Discourse. Characters of Species. Assyrian and Babylonian Antiquities and Ethnology. Recent discoveries in Assyria and Babylonia, with the results of Cunei- form research up to the present time. ..| Correlation of Physical Forces, The Atlantic Telegraph. Recent discoveries in Africa, The Ironstones of Yorkshire. .| The Fossil Mammalia of Australia. .| Sir R.I. Murchison, D.C.L. ...... Geology of the Northern Highlands. Electrical Discharges in highly rare- fied Media. Physical Constitution of the Sun. Arctic Discovery. Spectrum Analysis. The late Eclipse of the Sun. The Forms and Action of Water. Organic Chemistry. The chemistry of the Galvanic Bat- tery considered in relation to Dy- namics. The Balloon Ascents made for the British Association. The Chemical Action of Light. Recent Travels in Africa. Probabilities as to the position and extent of the Coal-measures beneath the red rocks of the Midland Coun- ties. The results of Spectrum Analysis applied to Heavenly Bodies, Insular Floras. The Geological origin of the present Scenery of Scotland. The present state of knowledge re- garding Meteors and Meteorites. Archeology of the carly Buddhist Monuments. Reverse Chemical Actions. Vesuyius. The Physical Constitution of the Stars and Nebulz. The Scientific Use of the Imagination. Stream-lines and Waves, in connexion with Naval Architecture. On some recent investigations and ap- plications of Explosive Agents. On the Relation of Primitive to Mo- dern Civilization. Insect Metamorphosis. The Aims and Instruments of Scien- tific Thought. xlii : REPORT—1872, ee ee ee eee eee el Date and Place. Lecturer. : Subject of Discourse. Lectures to the Operative Classes. 1867. Dundee...... Prof. J. Tyndall, LL.D., F.R.S.{ Matter and Force. 1868. Norwich ....] Prof. Huxley, LL.D., F.R.S. ...| A piece of Chalk. 1869, Exeter ...... Prof. Miller, M.D., F.R.S. ......| Experimental illustrations of the modes of detecting the Composi- tion of the Sun and other Heavenly Bodies by the Svectrum, 1870. Liverpool ...} Sir John Lubbock, Bart., M.P.,| Savages. ' F.R.S 1872, Brighton ... William Spottiswoode, LL.D.,!Sunshine, Sea, and Sky. E.RB.S. | Se *ZL81 ‘FT ysnsny ———— Il 1 800hF ‘TCOOMSILLOdS “AK Il 1 800k LZ 1 068 9 € ZL ‘* qaMNsvaxy, [eI8NeH Jo spueq ur =“ L SL L{8F Weg Jojsurwnyso\ pus uopuoy ye oourpe “FT ‘Sny y% 0 8IEee “GL8I © 6 TOF “T a8BsMag Jo UOTEZITYA) pues FMOMyLETT, WO 99;;{UTCMOK oP 0 0 sZt ‘XOd UNV 'V c “* s7eqayy Jo AGrAYJONpUOD [euT.E “ * 2 G0 tee ede os Suopipnp ITV NHOL 0 0 oP penne tee eee en eeeereweseneneees “999 “O14 SADUAAL NAMD ali? nyystog TRorMaYO “SIO Teyuess 0 0 OT Wsmosujuy seounysqng snouos1og te *7091109 PUNOF pUe PoUlMEXy 0 0 OL cites TTRAUTOT SIGE “ uO" OGn: SYIHUIT-9aw A OSMOATT x fn) 0 02 teen weee nee sqoalqo weunyT “ 0 0 &% eqTBTT JO syuvydorey [ssOuy fe ec eee eaovqISNig [ISsOT “ 0 0 &TI “pool 94} Url yoy 2 0 0 0Z eeeeee - 8.10099 TT snoumny “é 0 0 OOT * moneroldxp UI9ABH 8,400 NP oe 0 0 OL %* Sermbuy peorsopoAaqurpy-07e.10\F, LL Pree ee ees eB J cd “ Bee atta cierto hither) Geet «“ 6 zl eg tt gunoooy uorpedxg-esdyog yuommieaon =“ 0 0 *** STRIOD SNOdeFTUOgIeH WO 99441UTUIOS) Z 6 PSL OMOMOUCMmie Se ese +¢ ooHFETIO TSPLL — 1099) ®BOLGOTOO Tee e ee eee FO OT reaunesiunenienenesnt sees BR See BL oceee Patch x WOT] 482D JO WOTWNGTSTOD 0 0 00eR +++ LIOVCAIOSY MOY joguourysr(qeqysey SurUreUrE yy yeormeyD ou} Ul Sotpo.teasot m0 Burkard TOF ugs — "21a ‘Suyadjq YSinquipy ye opera syuery “ -SaTyiqe yl “IC 0} opeuL yuVLy Jo uoTj10d popuedxeuy a 0 cl 0Z1 see eeeeeeneaaseeee (900139 apvmeq| Vy ) sosuodxy 200 pue query “cc 0 11 ec Pee eee essere reseneeeseersstereees suoryeortqng jo ares Ioy i“ 0 0 OLF see eeeseeseee seees ee eeeseeeeserseese (avak 1) SOLIe]eg “ 0 0 Ces esocesseseseveceeseenesesessersereesers HIQIG uo spuaprlar(y “ 0 ol €P oo PUPUEEUETIE Ieee) (q3anquipq) 0 0 7GL 0331p 0341p ‘sjoyOLL Solpey “ "TX ‘OA ‘SuyooqY YSTP JO Wodey Jo yunoooer uo Suyuig “ 0G. 10: 916-°"""" oIp 0931p ‘sjoyory, Soyeloossy am Le 9 9/¢ rrr rrrr rr rrr rire) (joodaaary) 0 0 ErL eeeoneeee 0391p 0331p ‘suordizosqng jenuuy “ XIXXX ‘TOA ‘Suey WOF Jo woday ‘op ‘Saravasag ‘Suu “c 0 0 68¢ Preere Terie eee Tere re rere eer eee aouls 9 61 0sr °° sasuadxg Aqyag [eiUaplouy pue ‘SuisyyzoApy ‘Sut pue Suysayy ySmquipy ye suomisoduioy ery 1of paatsooy -purg ‘Sunutig Arpung osye ‘suneojy ysanquipy jo sosuedxy preg ZL OU BLE “oreeneerreeteetreeeeererees gumoooy 4se] TOY qysnorq soureg OF, eg ‘SLNIIWAVd 1 pee ‘SLdIGOaY (NOLHDING) LST sasny WPT ‘PONAIOS JO LNANAONVACV GHL YOA NOLLVIOOSSV HSiifdd AHb | xliv REPORT—1872. Table showing the Attendance and Receipts Date of Meeting. Where held. Presidents, Old Life | New Life Members. | Members. LOSEM CMe 7 veel tVOUE Maes tergede secs «se The Earl Fitzwilliam, D.C.I.... “of ; 1832 NG MO). ve oe| MOXTOLE Mees caveseess +2 The Rey. W. Buckland, F.R.S. .. aod ¥ 1333, June 25 ...|Cambridge ......... The Rey. A. Sedgwick, F.R.S.... nas 4 1834, Sept. 8 ...| Edinburgh ......... Sir T. M. Brisbane, D.C.L. ...... Se = TORS AM. CO. MDUDLIN ....0.00c0ss05 The Rey. Provost Lloyd, LL.D. ais ‘ TSQOmAUM. 22 45,c/(DTISHOL .1.scceccscens. The Marquis of Lansdowne...... na 1837, Sept. 11 ...| Liverpool ............ The Earl of Burlington, F.R.S.. ic 1838, Aug. 10 ...| Newcastle-on-Tyne..| The Duke of Northumberland... ss 1839, Aug. 26 ...| Birmingham ......... The Rey. W. Vernon Harcourt . She 1840, Sept.17 ...| Glasgow .........06 The Marquis of Breadalbane ... Bo 2 1841, July 20 ...| Plymouth ............ The Rey. W. Whewell, F.R.S.... 169 65 1842, June 23 ...| Manchester ......... The Lord Francis Egerton ...... 303 169 eAgeeAuo ny — 5. .|(COPK ey cccsscausaconnes The Earl of Rosse, F.R.S. ...... 109 28 MSAA SED E, 2Oi 50] MOVK os. ssesaecesssnese The Rey. G. Peacock, D.D....... 226 150 1845, June rg ...| Cambridge ......... Sir John F. W. Herschel, Bart. . 313 36 1846, Sept. ro ...|Southampton ...... Sir Roderick I. Murchison, Bart. 241 10 MOAT, PUNE 23 o.2|OXfOrd s.....s0scese0s Sir Robert H. Inglis, Bart. ...... 314 18 1848, Aug. 9...... SWANSEH rewars-veures The Marquis of Northampton... 149 3 1849, Sept. 12 ...| Birmingham ......... The Rey. T. R. Robinson, D.D.. 227 12 1850, July 21 ...| Edinburgh ......... | Sir David Brewster, K.H. ...... 235 9 Ti Sib Mey HOLY 2) oes 0 LOS WICH Issac cece notre G. B. Airy, Esq., Astron. Royal . 172 8 MSS2INEPt ee o.4|HCMABL \sesccnsvaseoac Lieut.-General Sabine, F. B.S. ... 164 Io NS Sy MEM gs sos | ERUN ecessstscessescne William Hopkins, Esq., F.R.S. . 141 13 1854, Sept. 20 ...| Liverpool ............ The Earl of Harrowby, F.R.S. .. 238 23 1855, Sept. 12 ...)| Glasgow ............ The Duke of Argyll, F.R.S. ...... 194 33 1856, Aug. 6.,.... Cheltenham ......... Prof. C. G. B. Daubeny, M.D.... 182 14 E857) Aue. 26, \...| DUDIM «4..s0.6:-cceves The Rey. Humphrey Lloyd, D.D. 236 15 ESS Os Eph.) 22 ar.| WCCOS ....0<0.0veseeases Richard Owen, M.D., D.C.L. ... 222 42 1859, Sept. 14 ...| Aberdeen ............ H.R.H. The Prince Consort ... 184 27 1860, June 27 ...| Oxford ©............... The Lord Wrottesley, M.A....... 286 21 1861, Sept. 4 ...| Manchester ......... William Fairbairn, LL.D.,F.RB.S. 321 113 1862, Oct. x .,.... Cambridge ......... The Rey. Prof. Willis, M.A. ... 239 15 1863, Aug. 26 ...| Newcastle-on-Tyne ..| Sir William G. Armstrong, C.B. 203 36 TAOA EP. 13% ..0| WAU seo -dasvescers vas Sir Charles Lyell, Bart., M.A.... 287 40 1865, Sept.6 ...| Birmingham ......... Prof. J. Phillips, M.A., LL.D.... 292 44 1866, Aug. 22 ...) Nottingham ......... William R. Grove, Q.C., F.R.S. 207 31 TSG7, Sept. A. .s+| DUDGESy,.spccnsesnvacs The Duke of Buccleuch, K.C.B. 167 25 1868, Aug. 19 ...| Norwich ..........-- Dr. Joseph D. Hooker, F.R.S. . 196 18 THOOWAUS, TS =, .| LEXOLEl las deacvescccses Prof. G. G. Stokes, D.C.L. ...... 204. 21 1870, Sept. 14 ...| Liverpool ............ Prof. T. H. Huxley, LL.D....... 314 39 1871, Aug. 2......| Edinburgh ......... Prof. Sir W. Thomson, LL.D.... 246 28 1872, Aug. 14 ...| Brighton ............ Dr. W. B. Carpenter, F.R.S ... 245 36 1873, Sept. 17 ...| Bradford ..... J. P. Joule, D.C.L., F.R.S. ...... ATTENDANCE AND RECEIPTS AT ANNUAL MEETINGS. xlv at Annual Meetings of the Association. Attended by Amount |S¥™s paid on : : oun Account of received Grants for Old New during the} ‘rants « ~ Annual Annual | Associates.| Ladies. | Foreigners.} ‘Total. Meeting. Purp EG “Members. | Members. Prpones: —!|—- Eis tht, tape Sem Gon cos a Pri ‘ Ark tae ET) RBar cee sasganseters ose eas QOORe slitercnmase . Seasasscve ee an ea P TZ O Sia a eee ae 20 0 O eee vee * weeny foe sae 167 9 0 ase . oo D5 OUE | a ceive ’ 434 14 0 ‘ Bt ont . 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T Tickets for admission to Sections only. ¢ Including Ladies. xlvi REPoRtT—1872. OFFICERS OF SECTIONAL COMMITTEES PRESENT AT THE BRIGHTON MEETING. SECTION A.—MATHEMATICS AND PHYSICS. President.—W arren De La Rue, D.C.L., Ph.D., F.R.S., V.P.R.A.S., V.P.C.S. Vice-Presidents.—Professor G. C. Foster, F.R.S.; Professor F. Fuller; James Glaisher, F.R.S.; Lord Lindsay, J. N. Lockyer, F.R.S.; Professor Phillips, F.R.S.; Professor H. J. 8. Smith, F.R.S.; W. Spottiswoode, LL.D., F.R.8.; Sir W. Thomson, LL.D., F.R.S.; Sir Charles Wheatstone, F.R.S. Secretaries.—Professor W. K. Clifford, M.A.; J. W. L. Glaisher, B.A., F.R.A.S, ;- Professor A. S. Herschel, B.A., F.R.A.S.; G. F. Rodwell, F.R.A.S, SECTION B.—CHEMISTRY AND MINERALOGY, INCLUDING THEIR APPLICATIONS TO AGRICULTURE AND THE ARTS. , President.—Dy. J. Hall Gladstone, F.R.S., F.C.S. Vice-Presidents.—F. A. Abel, F.R.S., F.C.8.; Professor A. Crum Brown, M.D., F.R.S.E.; Professor Williamson, F.R.S.; J. H. Gilbert, Ph.D., F.R.S.; Sir Benjamin Brodie, Bart., F.R.S.; Professor G. C. Foster, F.R.S. Secretaries.—Dr. Mills; W. Chandler Roberts, F.C.S.; Dr. W. J. Russell, F.R.S. 5, T. Wood, Ph.D. : ; SECTION C.—GEOLOGY. President.—R. A. C. Godwin-Austen, F.R.S., F.G.S. Ae ; Vice-Presidents—Thomas Davidson, F.R.S., F.G.S.; Professor P. Martin Duncan, D., F.R.S. F.G.S.; Rev. Thomas. Wiltshire, M.A., F.G.8., F.L.8.; Professor J. Phillips, M.A., LL.D., F.R.S.; J. Prestwich, F.R.S., F.G:S, un “ee Secretaries.—Henry Woodward, F.G.8.; Louis:‘C. Miall; George Scott; William’ Topley, E.G.8..- SECTION D.—BIOLOGY. President.—Sir John Lubbock, Bart., M.P., V.P.R.S. Vice-Presidents.—Professor Balfour, M.D., F.R.S.; John Ball, F.R.S.; John Beddoe M.D.; George Bentham, F.R.S.; J. Cordy Burrows, M.D.; T. Spencer Cobbold, M.D., F.R.S.; Professor Flower, F.R.S.; Col. A. Lane Fox, F.G.S; Joseph D, Hooker, C.B., M.D., F.R.S.; J. Gwyn Jeffreys, F.R.S.; J. Burdon Sanderson, M.D., F.R.S.; Professor Wyville Thomson, M.D., F.R.S. Secretaries.—Professor Thiselton-Dyer, B.A., H. T. Stainton, F.R.S.; Professor Lawson, F.L.8.; F. W. Rudler F.G.S.; J. H. Lamprey; Dr. Gamgee, F.R.S. ; Hi, Ray Lankester, M.A.; Dr. Pye-Smith. SECTION E.—GEOGRAPHY AND ETHNOLOGY. President.—F rancis Galton, F.R.S., F.G.S., F.R.G:S. Vice-Presidents—Clements R. Markham, C.B., F.L.S., F.R.G.S. ; Major-General Sir Henry Rawlinson, K.C.B., Pres. R.G.S.; Major-General Strachey, R.E., F.R.S., F.R.G.S.; Vice-Admizal Ommanney, C.B., F.R.S.. F.R.G.S.; John Arrowsmith, F.R.G.S.; A. G. Findlay, F.R.G.S. Secretaries.— W. H. Bates, F.R.G.S.; A. Keith Johnston, F.R.G.8.; Rev. J. Newton, M.A.; J. H. Thomas, F.R.G.S. 7 SECTION F.—ECONOMIC SCIENCE AND STATISTICS, President.—Professor Henry Fawcett, M.A., M.P. Vice-Presidents—Sir John Bowring; M. E. Grant Duff, M.P.; Sir James K. Alexander; Right Hon. J. G. Dodson, M.P.; James White, M.P.; R. Dudley Baxter, M.A.; William Newmarch, F.R.S. Secretaries.—J. G. Fitch, M.A.; Barclay Phillips. Srorrom G.—Mzxcwanicat Scrence. President.—¥. J. Bramwell, C.E. Vice-Presidents—John Hawkshaw, F-.R.S8.; C. W. Merrifield, F.R.S.; Charles B. Vignoles, F.R.S.; Prof. W. J. Macquorn Rankine, LL.D., F.R.S.; James Nasmyth, C.E.; W. Froude, F.R.S. Secretaries.—H. M. Brunel; P, Le Neve Foster, M.A.; John G. Gamble, B.A. ; James N, Shoolbred, OFFICERS AND COUNCIL, 1872-73. TRUSTEES (PERMANENT). General Sir EDWARD SABINE, K.C.B., R.A., D.C.L., F.R.S. Sir Purnip DE M. Grey-EGERTON, Bart., M.P., F.R.S., F.G.8 Sir Jonn Lussock, Bart., M.P., F.R.S., F.L.8, PRESIDENT. DR. W. B. CARPENTER, LL.D., F.R.S., F.L.S., F.G.8. VICE-PRESIDENTS. The Right Hon. the Fart or CuicHEsTER, Lord | His Grace The DUKE oF DEVONSHIRE, K.G., Lieutenant of the County of Sussex. D.C.L., F.R.S. His Grace The DuKE OF NORFOLK. Sir Joun LuBBockK,Bart.,M.P.,F.R.S.,F.L,.8.,1.G.8. His Grace The DUKE oF RicuMmonD, K.G., P.C., | Dr. SHARPEY, LL.D., Sec. R.S., F.L.S. D.C.L. J. PRESTWICH, Esq,, F.R.8., Pres. G.S, PRESIDENT ELECT. JAMES PRESCOTT JOULE,, Esq., D.C.L., LL.D., F.R.8. VICE-PRESIDENTS ELECT. The Right Hon. the HARL oF Rossk, F.R.S.,F.R.A.S8. J. P. Gasstot, Esq., D.C.L., LL.D., F.R.S. The Right Hon. Lorp Hovucuron, D.C.L., F.R.S, Professor Purtiips, D.C.L., LL.D., F.R.8 The Right Hon. W. E. ForstER, M.P, JoHN HAWKSHAW, Esq,, F.R.S., F.G.S. The MAYOR OF BRADFORD. LOCAL SECRETARIES FOR THE MEETING AT BRADFORD. The Rey. J. R. CAMPBELL, D.D. RIcHARD GoDDARD, Esq. PEILE THOMPSON, Esq. ‘ LOCAL TREASURER FOR THE MEETING AT BRADFORD, ALFRED Harris, Jun., Esq, ORDINARY MEMBERS OF THE COUNCIL. BATEMAN, J. F., Esq., F.R.S. LocxyYER, J. N., Esq., F.R.S. BrppdoE, JOHN, M.D. MERRIFIELD, C. W., Esq., F.R.S. Desus, Dr. H., F.R.S. NortTHcore, Rt.Hon.Sir STAFFORDH.,Bt.,M.P. Der La Rue, WARREN, Esq., F.R.S. Ramsay, Professor, LL.D., F.R.S. Evans, JounN, Esq., F.R.S. RAwuinson, Sir H., K.C.B., F.R.S. Firoug, J. G., Esq., M.A. SciaTER, Dr. P. L., F.R.S. FLoweEnk, Professor W. H., F.R.S. SIEMENS, C. W., Esq., D.C.L., F.R.S. Foster, Prof. G. C., F.R.S. STRACHEY, Major-General, F.R.S. GALTON, FRANCIS, Esq., F.R.S. STRANGE, Lieut.-Colonel A., F.R.8. Gopwin-Austen, R. A. C., Esq., F.R.S. TYNDALL, Professor, LL.D., F.R.S. Hirst, Dr. T, ARCHER, I'.R.S. WHEATSTONE, Professor Sir C., F.R.8. Hueeins, WILLIAM, Esq., D.C.L., F.R.S. WILLIAMSON, Professor A, W., F.R.S. JEFFREYS, J. Gwyn, Esq., F.R.S, EX-OFFICIO MEMBERS OF THE COUNCIL. The President and President Elect, the Vice-Presidents and Vice-Presidents Elect, the General and Assistant General Secretaries, the General Treasurer, the Trustees, and the Presidents of former years, viz. :— The Duke of Devonshire. ! Richard Owen, M.D., D.C.L. Sir William R. Grove, F.R.S. The Rey. T. R. Robinson, D.D. Sir W. Fairbairn, Bart., LL.D. The Duke of Buccleuch, K.B. Sir G. B. Airy, Astronomer Royal. | The Rey. Professor Willis, F.R.S. | Dr. Joseph D. Hooker, D.C.L. General Sir BE. Sabine, K.C.B. Sir W. G. Armstrong, O.B., LL.D. | Professor Stokes, C.B., D.C.L. The Earl of Harrowby. Sir Chas. Lyell, Bart., M.A.,LL.D. | Prof. Huxley, LL.D. The Duke of Argyll. Professor Phillips, M.A., D.C.L, | Prof. Sir W. Thomson, D,C.L. The Rey. H. Lloyd, D.D. GENERAL SECRETARIES. Capt. DovGLAs GALTON, C.B., R.E., F.R.S., F.G.8., 12 Chester Street, Grosvenor Place, London, 8.W. Prof. MicHaEL FostEr, M.D., E.R.8., Trinity College, Cambridge. ASSISTANT GENERAL SECRETARY, GroRGE GRIFFITH, Esq., M.A., Harrow-on-the-hill, Middlesex, _ GENERAL TREASURER. WILLIAM SPorriswoonk, Esq., M.A., LL.D., F.R.S., F.R.G.S., 50 Grosvenor Place, London, 8.W. AUDITORS. John Ball, Esq., F.R.S. J. Gwyn Jeffreys, Esq., F.R.8, Colonel Lane Fox F.G.S, xlvi_ REPORT—1872. Report of the Council for the Year 1871-72 presented to the General Committee at Brighton, on Wednesday, August 14th, 1872. At each of their Meetings during the present year, the Council have received a Report from the General Treasurer, and his Report for the year will be laid before the General Committee this day. The Council have to announce that a vacancy has occurred in the number of the Trustees in consequence of the death of Sir Roderick Murchison. The Council take this opportunity of expressing their regret at the great loss which Science has sustained by his death. He worked long, earnestly, and with eminent success in the Sciences of Geology and Geography, and was at all times a steady patron of rising Scientific Men in all branches of Science. He was a Member and strenuous supporter of this Association at its first formation in 1831, and continued until the close of his life a very constant attendant at its Meetings and a firm promoter of its interests. - The Council recommend that Sir John Lubbock, Bart., be selected to fill the vacancy. The list of Sectional Officers, which the Council will submit to the General Committee, has been arranged in accordance with the resolution of the General Committee at the Meeting at Edinburgh in 1871, viz. the Section of Biology has been divided into the three Departments of Anatomy and Physiology, Anthropology, and Zoology and Botany, and the Council have designated the Chairmen and Secretaries to take charge of the several Departments. In accordance with the following resolution of the General Committee at Edinburgh, viz. :— That the President and General Officers, with power to add to their number, be requested to take such steps as may scem to them desi- rable in order to promote observations on the forthcoming Total Solar Eclipse, a Committee was formed, consisting of the President, and General Officers of the Association, Professor J. C. Adams, Sir G. B. Airy, Astronomer Royal, Professor Clifton, Mr. De La Rue, Dr. Frankland, Mr. Hind, Mr. Lassell, President R.A.S., Lord Lindsay, Mr. Lockyer, General Sabine, General Stra- chey, Colonel Strange, and Professor Stokes; and a Letter was addressed by the President to the First Lord of the Treasury, requesting the Government to contribute £2000 towards the expenses of the Expedition, to afford to the Expedition the assistance of a Government Steamer to convey the parties composing it to the Stations for observation selected on the Coasts of Ceylon and India, and to obtain for the Expedition the cooperation of the Goyernor- General of India and of the Governor of Ceylon. Her Majesty’s Government acceded to the request contained in this letter. The Expedition was formed by the Committee, and proceeded to Ceylon and India in the charge of Mr. Lockyer and Dr. Thomson. The Governor-General of India and the Governor of Ceylon forwarded the objects of the Expedition by all means in their power. REPORT OF THE COUNCIL. xlix The report of the proceedings and results of the Expedition will be pre- sented to the Association by the Eclipse Committee in the usual course. _ The Council have received a communication from the Royal Astronomical Society, informing them that that body contemplated printing, in a separate volume of their Transactions, the results of the observations of the Solar Eclipses of 1860 and 1870; and that, under these circumstances, they con- sidered it would be advantageous to Science to publish, in the same manner, the results of the Observations made in 1871, under the auspices of the British Association; thus presenting a Record of all these Observations in one uniform Series. The Council resolved to accept the proposal of the Council of the Royal Astronomical Society, and they appointed a Committee, consisting of Mr. Warren De La Rue, Colonel Strange, Dr. Huggins, and Mr. Lockyer, to arrange the necessary details with the Council of the Royal Astronomical Society. There were five other resolutions referred to the Council for consideration or action, upon which the proceedings of the Council have been as follows :— First Resolution.—“ That the President and Council of the British Asso- ciation be authorized to cooperate with the President and Council of the Royal Society, in whatever way may seem to them best, for the promotion of a Circumnavigation Expedition, specially fitted out to carry the Physical and Biological Exploration of the Deep Sea into all the Great Oceanic areas.” A copy of this Resolution was forwarded to the Royal Society, and a Com- mittee was appointed, consisting of the President and Officers of the Asso- ciation, Dr. Carpenter, Professor Huxley, Mr. Gwyn Jeffreys, Mr. C. W. Siemens, and Professor Williamson, and authorized to cooperate with the Committee of the Royal Society in carrying out the objects referred to in the Resolution. The Expedition has been organized, the ship ‘Challenger’ is being fitted out at Sheerness, Captain Nares has been appointed to the com- mand, and Professor Wyville Thomson (who has obtained three years’ leave of absence from the University of Edinburgh) is appointed to the Scientific charge, with an adequate Staff under him. It is hoped that the Expedition will sail about the end of November. ~ Second Resolution.— ‘1. That it is desirable that the British Association apply to the Treasury for Funds to enable the Tidal Committee to make observations and to continue their calculations. “2. That it is desirable that the British Association should urge upon the Government of India the importance, for navigation and other practical purposes, and for science, of making accurate and continued observations on the Tides at several points on the coast of India.” The Council added General Strachey to the Committee on Tides, The Government of India, upon their application, have agreed to defray the expense of making Tidal observations in India, and of causing the experi- ments to be reduced according to the methods devised by the Committee on Tides. In pursuance of the first part of this Resolution, the Committee on Tides being authorized by the Council to make an application to the Government, presented the following Memorial to the Lords Commissioners of H.M. Treasury :— 1 REPORT—1872. “To the Right Honourable the Lords Commissioners of Her Majesty’s Treasury, The Memorial of the British Association for the Advancement of Science. ‘Humpty SHEWETH, “1, That in the year 1867 the British Association appointed a Com- mittee ‘for the purpose of promoting the extension, improvement, and harmonic analysis of tidal observations.’ From that time until the present, under Committees reappointed from year to year, the proposed work has been carried on. The mode of procedure adopted, and the results obtained up - to the month of August 1871, are fully stated in the accompanying series of printed reports. — «2, The primary object of the investigation is the advance of tidal science ; but the Committee have uniformly kept in view the practical application of their results to Physical Geography, Meteorology, Coast and Harbour Engineering, and Navigation. «3. A large mass of valuable observations recorded by self-registering tide-gauges during the last twenty years having been found available, the Committee have applied themselves in the first place to the reduction of these observations, and have deferred the object of promoting observations in other localities until the observations already made have been utilized to the utmost. «4, The work thus undertaken has proved, as was anticipated, most laborious. The calculations have been performed, under the superintend- ence of Sir William Thomson, by skilled calculators recommended by the Nautical Almanac Office. The funds required to pay the calculators, and to print and prepare Tables, forms for calculation, &c., to the amount of £600, have been granted by the British Association in four successive annual allowances of £100 each, and a sum of £200 voted at the last Meeting. The last grant barely sufficed for the work actually in hand, and to secure the continuance of the investigation additional funds are necessary. The Council of the British Association therefore directed the Tidal Committee to make an application to the Government for assistance, the amount at present asked for being limited to £150. «<5. It seemed to the Council that after the Association had done so much in the way of actual expenditure of time by the Members of its Committee, and had given such a large contribution from its very limited funds, enough had been done to show the object to be one for which assistance may reasonably be expected from Government. On representations made by Colonel Walker, Director of the Trigonometrical Survey of India, the Indian Government has already granted the means of defraying the expense of making Tidal Observations in India, and applying to them the methods of reduction devised by the Committee of the British Association. The Council hope, therefore, that the Government of this country may be similarly dis- posed to assist in a matter of national importance. (Signed) «“ WirtttaAm THomson, er President of the British Association.” * May 21, 1872.” The Council regret to state that the application was rejected upon the grounds explained in the following letter :— “ Treasury Chambers, ai 3rd June, 1872, | “Si,—The Chancellor of the Exchequer has referred to the Lords Com- missioners of Her Majesty’s Treasury the Memorial of the British Association ee ee. ees SS) et REPORT OF THE COUNCIL. li for the Advancement of Science, forwarded to him with your letter of 21st ultimo, praying for Government assistance in connexion with Tidal Obser- vations. **T am to state that their Lordships have given their anxious attention to the Memorial, and they are fully sensible of the interesting nature of such investigations, but that they feel that if they acceded to this request, it would be impossible to refuse to contribute towards the numerous other ob- jects which men of eminence may desire to treat scientifically. “Their Lordships must, therefore, though with regret, decline to make a promise of assistance towards the present object out of the public funds. Tam, Sir, , “Your obedient Servant, (Signed) Wittam Law.” «Sir W. Thomson, Athenceum Club.” Third. Resolution.-—** That the Council of the Association be requested to take such steps as to them may seem most expedient in support of a proposal, made by Dr. Buys Ballot, to establish a telegraphic meteorological station at the Azores.” The Council appointed a Committee of their own body to report upon this proposal,- The Committce after due deliberation reported that, while sympa- thizing with the proposal made by Dr. Buys Ballot, they cannot recommend a grant of money to be made by the Association for carrying it out. In this recommendation the Council concur. Fourth Resolution— That the Council be requested to take into con- sideration the desirability of the publication of a periodic record of advances made in the yarious branches of science represented by the British Associa- tion.” The Council, after a careful consideration of this proposal, are not prepared to recommend the Association to undertake the publication of a periodic record of advances made in the various branches of science represented by the Sections of the British Association. They are of opinion that in so vast an undertaking special Societies should be invited to prepare such records, the action of the Association being limited to occasional grants in aid. They are of opinion, however, that the Association would do well to promote the more frequent publication in their Proceedings of critical reports on various branches of science, of the same nature as those which have already rendered previous volumes so valuable to investigators. Fifth Resolution. ‘1. That the Couneil of this Association be requested ‘to take such steps as may appear to them desirable with reference to the arrangement now in contemplation to establish ‘Leaving Examinations,’ and to report to the Association on the present position of science-teaching in the public and first-grade schools. **2. That the Council be requested to take such steps as they deem wisest in order to promote the introduction of scientific instruction into the ele- mentary schools throughout the country.” A Committee, consisting of the President and the General Officers, Mr. G. Busk, Dr. Debus, Dr. Duncan, Mr. Fitch, Professor M. Foster, Mr. F. Galton, Dr. Hirst, Professor Huxley, Sir John Lubbock, Bart., Sir J. Paget, Bart., Rey. Professor Price, Professor Henry J.8, mith, Professor Stokes, Professor Tyndall, and Professor Williamson, was appointed to consider the first of these resolutions, and to report on them to the Council. d2 hi rePORT—1872. In accordance with the recommendation of this Committee the Council adopted the following Resolution :— That, having had under consideration the requests which the Committee of Masters of Schools have made to the Universities of Oxford and Cambridge upon points in which the Education of the Universities and Schools came into contact, the Council of the British Association recommend that Arithmetic, and either Elementary Physics or Che- mistry experimentally treated, be introduced into the Leaving Exa- minations as compulsory subiects. That the Head-Masters of Public Schools be requested to furnish the Council with information about the present position of Science- teaching in their Schools. and the Council have communicated thereon with the Universities of Oxford and Cambridge, but at present no decision respecting “‘ Leaving Examinations” has been arrived at in these Universities. In accordance with the terms of the resolution passed by the General Committee last year, appointing a Committee on Science Lectures and Orga- nization, the action proposed to be taken by this Committee in the following resolutions, was referred to the Council and sanctioned. 1. That a Subcommittee, consisting of Dr. Carpenter, Prof. Williamson, Prof. W. G. Adams, Dr. Hirst, Mr. Geo. Griffith, De. Michael Foster, and Prof. Roscoe be appointed for one year for the purpose of preparing a list of Lecturers for the consideration of this Committee, and of communicating with the various towns with the view of establishing a system of Science Lectures throughout the country. 2. That the names of the proposed Lecturers be selected (with their consent) from amongst the Members of the General Committee of the Association, or from amongst the Graduates of any University in the United Kingdom; and that the subjects upon which the Lectures be de- livered shall be such as are included in one or other of the Sections of the Association. The Committee have drawn up a Report, dealing generally with the sub- ject of their inquiry, which the Council recommend should be referred to the Committee of Recommendations. The Council have had under consideration the question of enabling Members, who are unable to be present at the Meetings, to obtain the Journal and other Printed Papers, and they have adopted a Regulation as follows :— The Journal, President’s Address, and other Printed Papers issued by the Association during the Annual Meeting will be forwarded daily to Members and others, on application and prepayment of 2s. 6d. to the Clerk of the Association, on or before the first day of the Meeting. The Council regret to have to announce that the state of health of Dr. Thomas Thomson renders him unable to continue to act as one of the General Secretaries of the Association after the present Meeting. They cannot refrain from expressing their great regret at the loss of his valuable services. The Council have agreed to recommend that Professor Michael Foster, F.R.S., be appointed one of the General Secretaries in his place, and his name will be proposed to the General Committee at the Meeting for the Election of the Council and Officers on Monday next. , The Council haye added the following names of gentlemen; present RECOMMENDATIONS OF THE GENERAL COMMITTEE. lh at the last Meeting of the Association, to the list of Corresponding Members, viz. i— His Imperial Majesty the Emperer of the Brazils. Professor Dr, Colding. Dr. Giissfeldt. Dr. Liiroth. Dr. Liitken. Dr. Joseph Szabo. The General Committee are reminded that Bradford has been selected as the place of mecting for next year. Invitations for subsequent Mectings haye been received from Belfast and Glasgow, RECOMMENDATIONS ADOPTED BY THE GENERAL CoMMITIEE AT THE BRIGHTON oa Meetine in Aveusr 1872. [When Committees are appointed, the Member first named is regarded as the Secretary, except there is a specific nomination. ] Involving Grants of Money. That the Committee, consisting of Professor Cayley, Professor Stokes, Professor H. J. S. Smith, Sir W. Thomson, and Mr. J. W. L. Glaisher (Se- cretary), on Mathematical Tables be reappointed, with a grant of £100 for the calculation and printing of numerical tables. That the Committee on Tides, consisting of Sir W. Thomson, Professor J. C. Adams, Professor W. J. M. Rankine, Mr. J. Oldham, Rear-Admiral - Richards, General Strachey, Mr. W. Parkes, and Colonel Walker, be reap- pointed, with a grant of £400 to complete the reduction of Tidal Observations from existing data, and that an urgent recommendation be made to the Government to undertake Tidal Observations and their reduction. That the Committee for reporting on the Rainfall of the British Isles be reappointed, and that this Committee consist of Mr. Charles Brooke, Mr. Glaisher, Professor Phillips, Mr. G. J. Symons, Mr. J. F. Bateman, Mr. R. W. Mylne, Mr. T. Hawksley, Professor J. C. Adams, Mr. C. Tomlinson, Professor Sylvester, Dr. Pole, Mr. Rogers Field, Professor Ansted, and Mr, Buchan ; that Mr. G. J. Symons be the Secretary, and that the sum of £100 be placed at their disposal for the purpose. That the Committee on Underground Temperature, consisting of Professor Everett (Secretary), Sir W. Thomson, Sir Charles Lyell, Bart., Professor J. Clerk Maxwell, Professor Phillips, Mr. G. J. Symons, Professor Ramsay, Professor Geikie, Mr. Glaisher, Rev. Dr. Graham, Mr. George Maw, Mr. Pengelly, Mr. S. J. Mackie, Professor Edward Hull, and Professor Ansted, be reappointed ; that Mr. Joseph Prestwich be added to the Committee, and that the sum of £150 (£100 being a grant already made which has lapsed) be placed at their disposal for the purpose. That a grant of £50 having been made for the Calculation of the Gaussian Constants, and only £40 having been drawn by the late Chairman Sir J. Herschel, the remaining £10 be regranted te Mr. G. Griffith and Professor Erman for expenses already incurred. That the Committee on Luminous Meteors, consisting of Mr. Glaisher, Mr. R. P. Greg, Professor A. 8. Herschel, be reappointed, with a grant of £30 for projecting and reducing upon suitable maps the observations of meteors liv REPORT—1872, collected during the last few years by the Committee, so as to show their radiant points. That Mr. Glaisher, Col. Strange, Sir W. Thomson, Mr. Brooke, Mr. Walker, Dr. Mann, and M. de Fonvielle be a Committee for the purpose of investigating the efficacy of Lightning-conductors, giving suggestions for their improvement, and reporting upon any case in which a_building has been injured by lightning, especially where such building was professedly protected by a lightning-conductor, and that the sum of £50 be placed at their dis- posal for the purpose. That Professor A. W. Williamson, Sir W. Thomson, Professor Clerk Max- well, Professor G. C. Foster, Mr. Abel, Professor F. Jenkin, Mr. Siemens, and Mr. R. Sabine be reappointed a Committee for the purpose of testing the New Pyrometer of Mr. Siemens, and that the sum of £30 be placed at their disposal for the purpose. That the Committee, consisting of Dr. Huggins, Mr. J. N. Lockyer, Dr. Reynolds, Professor Swan, and Mr. Stoney, on Inverse Wave-lengths be reappointed, and that the sum of £150 be placed at their disposal. That the Committee on the Thermal Conductivity of Metals, consisting of Professor Tait, Professor Tyndall, and Professor Balfour Stewart, be reap- pointed, and that the sum of £50 be placed at their disposal for the purpose. That Professor Williamson, Professor Roscoe, and Professor Frankland be a Committee for the purpose of superintending the Monthly Records of the Progress of Chemistry published in the Journal of the Chemical Society, and that the sum of £200 (last year’s grant of £100 was not drawn) be placed at their disposal for the purpose. That Dr. Gladstone, Dr. C. R. A. Wright, and Mr. Chandler Roberts be reappointed a Committee for the purpose of investigating the chemical consti- tution and optical proporties of essential oils ; that Mr. Chandler Roberts be the Secretary, and that the sum of £30 be placed at their disposal for the purpose. That Dr. Crum Brown, Mr. Dewar, Dr. Gladstone, Dr. Williamson, Sir W. Thomson, and Professor Tait be a Committee for the purpose of deter- mining the temperatures of incandescent bodies by the refrangibility of the light they emit, and that the sum of £50 be placed at their disposal for the purpose. That Dr. Crum Brown, Professor Tait, and Mr. Dewar be a Committee for the purpose of investigating the Electric Tensions of galvanic cells in which the oxides or acids of chlorine or iodine form the liquid elements, and that the sum of £25 be placed at their disposal for the purpose. That Professor Ramsay, Professor Geikie, Professor J. Young, Professor Nicol, Dr. Bryce, Dr. Arthur Mitchell, Professor Hull, Sir R. Griffith, Bart., Dr. King, Professor Harkness, Mr. Prestwich, Mr. Hughes, Rev. Hi. W. Crosskey, Mr. W. Jolly, Mr. D. Milne Home, and Mr. Pengelly be reappointed a Committee for the purpose of ascertaining the existence in different parts of the United Kingdom of any Erratic Blocks or Boulders, indicating on Maps their position and height above the sea, as also of ascer- taining the nature of the rocks composing these blocks, their size, shape, and other particulars of interest, and of endeavouring to prevent the destruc- tion of such blocks as in the opinion of the Committee are worthy of being preserved ; that the Rev. H. W. Crosskey be the Secretary, and that the sum of £10 be placed at their disposal for the purpose. That Sir C, Lyell, Bart., Professor Phillips, Sir J. Lubbock, Bart., Mr. RECOMMENDATIONS OF THE GENERAL COMMITTEE, lv J. Evans, Mr. E. Vivian, Mr. W. Pengelly, Mr. G. Busk, Mr. W. B. Dawkins, and Mr, W. A. Sandford be a Committee for the purpose of continuing the Exploration of Kent’s Cavern, Torquay ; that Mr. Pengelly be the Secretary, and that the sum of £150 be placed at their disposal for the purpose. That Sir J. Lubbock, Bart., Professor Phillips, Messrs. W. Boyd Dawkins, and T. McKenny Hughes, be a Committee for the purpose of carrying out the exploration of the Settle Cave; that Mr. W. Boyd Dawkins be the Se- ceretary, and that the sum of £50 be placed at their disposal for the purpose. That Mr. G. Busk, Dr. Leith Adams, and Mr. Boyd Dawkins be reap- pointed a Committee for the purpose of illustrating by plates an account of the Fossil Elephants of Malta; that Dr. Leith Adams be the Secretary, and that the sum of £25 be placed at their disposal for the purpose. That Professor Harkness, Mr. James Thomson, Dr. Duncan, and Mr. Thomas Davidson be reappointed a Committee for the purpose of continuing the investigation of Carboniferous Corals with the view of reproducing them for publication ; that Mr. Thomson be the Secretary, and that the sum of £25 be placed at their disposal for the purpose. That Mr. Carruthers, Mr. W. H. Baily, Professor Harkness, and Professor Hull be a Committee for the purpose of investigating the Fossil Flora of Ireland; that Mr. W. H. Baily be the Secretary, and that the sum of £20 be placed at their disposal for the purpose. That Professor Harkness, Mr. W. Jolly, and Dr. J. Bryce be a Committee for the purpose of collecting Fossils from localities of difficult access in North- western Scotland, that the specimens be deposited in the Edinburgh In- dustrial Museum, and that duplicates be deposited in such Museums as the authorities of the Association may designate; that Mr. William Jolly be the Secretary, and that the sum of £10 be placed at their disposal for the | purpose, That Dr. Bryce, Sir W. Thomson, Mr. J. Brough, Mr. G. Forbes, Mr. D. Milne Home, and Mr. James Thomson be a Committee for the purpose of continuing the observations and records of Earthquakes in Scotland; that Dr. Bryce be the Secretary, and that the sum of £20 be placed at their disposal for the purpose. That Messrs. H. Willett, Godwin-Austen, W. Topley, T. Davidson, J. Prestwich, W. Boyd Dawkins, and H. Woodward be a Committee for the pur- pose of promoting the “ Sub-Wealden exploration ;” that Mr. Henry Willett be the Secretary, and that the sum of £25 be placed at their disposal for the urpose. é That Colonel Lane Fox, Dr. Beddoe, Mr. Franks, Mr. Francis Galton, Mr. E. W. Brabrook, Sir J. Lubbock, Bart., Sir Walter Elhot, Mr. Clements R. Markham, and Mr. E. B. Tylor be a Committee for the purpose of pre- paring and publishing brief forms of instruction for travellers, ethnologists, and other anthropological observers ; that Colonel Lane Fox be the Secre- tary, and that the sum of £25 be placed at their disposal for the purpose. That Mr. Stainton, Professor Newton, and Sir John Lubbock, Bart., be reappointed a Committee for the purpose of continuing a Record of Zoolo- gical Literature ; that Mr. Stainton be the Secretary, and that the sum of £100 be placed at their disposal for the purpose. That Professor Sir Robert Christison, Bart., Dr. Laycock, and Dr. Fraser be a Committee for the purpose of investigating the antagonism of the action of poisonous substances; that Dr. Fraser be the Secretary, and that the sum of £20 be placed at their disposal for the purpose. That Professor Balfour, Dr. Cleghorn, Mr, Robert Hutchinson, Mr, Buchan, lyi REPORT—1872. and Mr. Sadler be reappointed a Committee for the purpose of taking obser- vations on the effect of the denudation of timber on the rainfall of North Britain ; that Mr. Hutchinson be the Secretary, and that the sum of £20 be placed at their disposal for the purpose, the grant made last year not haying been drawn. That the Committee for the purpose of continuing the investigations on the Treatment and Utilization of Sewage be renewed, and that such Com- mittee consist of Mr. R. B. Grantham, Professor Corfield, Mr. J. Bailey Denton, Mr. Bramwell, Dr. J. H. Gilbert, Mr. W. Hope, Dr. A. Voelcker, Professor Williamson, and Professor Way, and that the sum of £100 be placed at their disposal for the purpose. That the Committee, consisting of Mr. Froude, Professor W. J. Macquorn Rankine, Mr. C. W. Merrifield, Mr. C. W. Siemens, Mr. Bramwell, Mr. A. E. Fletcher, the Rev J. Berthon, Mr. Shoolbred, Mr, James R. Napier, and Mr. W. Smith previously appointed for measuring the speed of ships by means of the difference of the height of two cclumns of liquid, be requested to report generally on the subject of instruments for testing the speed of ships, and that they be requested to present a separate report on the special class of instru- ments therein referred to them; that the sum of £50 be placed at their dis- posal for the purpose, and that Mr. J. Shoolbred be the Secretary. Applications for Reports and Researches not involving Grants of Money. That the Committee, consisting of Dr. Joule, Sir W. Thomson, Professor Tait, Professor Balfour Stewart, and Professor J. C. Maxwell, be reappointed to effect the determination of the Mechanical Equivalent of Heat. That the Mclipse Committee, consisting of the President and General Offi- cers (with power to add to their number), be reappointed. That Sir W. Thomson, Professor Everett, Professor G. C. Foster, Professor J. C. Maxwell, Mr. G. J. Stoney, Professor Fleeming Jenkin, Professor Ran- kine, Dr. Siemens, and Mr. Bramwell be a Committee for reporting on the Nomenclature of Dynamical and Electrical Units, and that Professor Everett be the Secretary. That Professor Sylvester, Professor Cayley, Professor Hirst, Rev. Professor Bartholomew Price, Professor H. J. 8. Smith, Dr. Spottiswoode, Mr. R. B. Hayward, Dr. Salmon, Rey. R. Townsend, Professor Fuller, Professor Kel- land, Mr. J. M. Wilson, and Professor Clifford be reappointed a Committee (with power to add to their number) for the purpose of considering the pos- sibility of improving the methods of instruction in elementary geometry ; and that Professor Clifford be the Secretary. That Mr. W. H. L. Russell be requested to continue his Report on recent progress in the theory of Elliptic and Hyperelliptic Functions. That Professor Tait be requested to prepare a Report on Quaternions. That the Committee, consisting of the following Members, with power to add to their number,—Professor Roscoe, Professor W. G. Adams, Professor Andrews, Professor Balfour, Mr. Baxendell, Mr. Bramwell, Professor A. Crum Brown, Mr. Buchan, Dr. Carpenter, Professor Core, Dr. De La Rue, Professor ‘Thiselton Dyer, Sir Walter Elliot, Professor M. Foster, Professor Flower, Pro- fessor G. C. Foster, Professor Geikie, Dr. J. H. Gladstone, Mr. Griffith, Rey. Rt. Harley, Dr. Hirst, Dr. Hooker, Dr. Huggins, Professor Huxley, Professor Fleeming Jenkin, Dr. Joule, Colonel Lane Fox, Dr. Lankester, Mr. J. N. Lockyer, Professor Clerk Maxwell, Mr. D. Milne-Home, Dr. O'Callaghan, Dr, Odling, Professor Ramsay, Dr. Spottiswoode, Professor Balfour Stewart, RECOMMENDATIONS OF THE GENERAL COMMITTEE. lvii Mr. Stainton, Professor Tait, Mr. J. A. Tinné, Dr. Allen Thomson, Sir William Thomson, Professor Wyville Thomson, Professor Turner, Colonel Strange, Professor A. W. Williamson, Mr. G. VY. Vernon, Dr. Young; and that Pro- fessor Roscoe be the Secretary,—be reappointed— 1°, to consider and report on the best means of advancing science by Lectures, with authority to act, subject to the approval of the Council, in the course of the present year, if judged desirable. 2°, to consider and report whether any steps can be taken to render scientific organization more complete and effectual. That Mr. Roberts, Dr. Mills, Dr. Stenhouse, Dr. Boycott, and Mr. Gades- den be a Committee for the purpose of inquiring into the method of making gold assays, and stating the results thereof; that Mr. W. C. Roberts be the Secretary. That Professor Phillips, Professor Harkness, Mr. Henry Woodward, Mr. James Thomson, and Mr. L. C. Miall be a Committee for the purpose of investigating and reporting’upon the Labyrinthodonts of the Coal-measures ; and that Mr. L. C. Miall be the Secretary. That the Rey. Canon Tristram, Professor Newton, Mr. H. E. Dresser, Mr. J. E. Harting, and the Rev. H. F. Barnes, with the addition of Mr. Harland of Bridlington, and Mr. Monk of Lewes, be appointed a Committee for the purpose of continuing the investigation on the desirability of establishing ‘a close time ” for the preservation of indigenous animals; that Mr. H. E. Dresser be the Secretary. That Dr. Rolleston, Dr. Sclater, Dr. Anton Dohrn, Professor Huxley, Pro- fessor Wyville Thomson, and Mr. E. Ray Lankester be reappointed a Com- mittee for the purpose of promoting the foundation of Zoological Stations ; that Dr. Anton Dohrn be the Secretary. That Dr. Arthur Gamgee, Mr. E. Ray Lankester, and Professor M. Foster be a Committee for the purpose of investigating the amount of Heat gene- rated in the Blood in the process of Arterialization; that Dr. Gamgee be the Secretary. That Mr. Carruthers, Dr. Hooker, Professor Balfour, and Professor Thisel- ton Dyer be reappointed a Committee for the purpose of investigating the Fossil Flora of Britain; that Mr. Carruthers be the Secretary. That the Metric Committee be reappointed, such Committee to consist of Sir John Bowring, The Right Hon. Sir Stafford H. Northcote, Bart., C.B., M.P., The Right Hon. C. B. Adderley, M.P., Mr. Samuel Brown, Dr. Farr, Mr. Frank P. Fellcwes, Professor Frankland, Mr. James Heywood, Pro- fessor Leone Levi, Mr. C. W. Siemens, Professor A. W. Williamson, Dr. George Glover, Sir Joseph Whitworth, Bart., Mr. J. R. Napier, Mr. J. V. N. Bazalgette, and Sir W. Fairbairn, Bart.; that Professor Leone Levi be the Secretary. That Professor Cayley, Mr. J. W. L. Glaisher, Dr. W. Pole, Mr. Merrifield, Professor Fuller, Mr. H. M. Brunei, and Professor W. R. Clifford be a Com- mittee to estimate the cost of constructing Mr. Babbage’s Analytical Engine, and to consider the advisability of printing tables by its means. That a Committee, consisting of Mr. Francis Galton, Mr. W. Froude, Mr, C. W. Merrifield, and Professor Rankine, be appointed to consider and report on Machinery for obtaining a record of the roughness of the Sea and Mea- surement of Wayes near shore. vill REPORT—1872. That Sir Henry Rawlinson, Mr. Francis Galton, Admiral Ommanney, Mr. Hawkshaw, Mr. Bramwell, Mr. De La Rue, and Mr. Godwin-Austen be a Committee (with power to add to their number) for the purpose of represent- ing to the Government the advisability of an issue of the one-inch Ordnance Maps, printed on strong thin paper, each sheet having a portion of an index map impressed on the outside, to show its contents and those of the adjacent sheets and their numbers. Also that these maps should be sold in all im- portant towns and, if possible, at the several Post-offices; that Mr. Francis Galton be the Secretary. Resolutions referred to the Council for consideration and action if tt seem desirable. That the Council be requested to take such steps as they deem desirable to induce the Colonial Ofiice to afford sufficient aid to the Observatory at Mau- ritius to enable an investigation of the Cyclones of the Pacific Ocean to be carried on there. ! That, in the event of the Council haying reason to believe that any changes affecting the acknowledged efficiency and scientific character of the Botanical Establishment at Kew are contemplated by the Government, the Council be requested to take such steps as in their judgment will be conducive to the interests of Botanical science in this country. That the Council be requested to take such steps as they may deem desi- rable “to urge upon the Indian Government the preparation of a Photohelio- graph and other instruments for solar observation, with the view of assisting in the observation of the Transit of Venus in 1874, and for the continuation of solar observations in India.” Communications ordered to be printed in extenso in the Annual Report of the Association. That M. Hermite’s paper, “ Sur l’élimination des fonctions arbitraires,” be printed in extenso among the Reports. That the Tabulated List of species given in Mr. J. Gwyn Jeffreys’s paper on the correlation of the European and North-American Mollusca be printed in the Reports of the Association. That Mr. Froude’s paper “ On the Frictional Resistance of Surfaces immersed in Fluids” be printed in eatenso in the Transactions, with the illustrations. That Mr. Easton’s paper on the Brighton Waterworks be printed in extenso in the Transactions. < That Mr. Bramwell’s paper on Amsler’s Planimeter be printed im extenso in the Transactions, SYNOPSIS OF GRANTS OF MONEY. lix Synopsis of Grants of Money appropriated to Scientific Purposes by the General Committee at the Brighton Meeting in August 1872. The names of the Members who would be entitled to call on the General Treasurer for the respective Grants are prefixed. Mathematics and Physics. *Cayley, Professor.—Mathematical Tables ................ 100 *Thomson, Professor Sir W.—Tidal Observations .......... 400 morooke, Mr.——British; Rainfall... s., s/s sc esis siesic cee 0 0 Sikhs 100 *Hverett, Prof—Underground Temperature (£100 renewed).. 150 *Griffith, Mr. G.—Gaussian Constants (renewed) .......... 10 *Glaisher, Mr. J——Luminous Meteors ................0..0. 3 Glaisher, Mr. J.— Efficacy of Lightning Conductors ........ 50 *Williamson, Prof. A. W.—Testing Siemens’s New Pyrometer EM ac ake a i SNE < he cid 2s ees a gehen 30 *Huggins, Dr. W.—Tables of Inverse Wave-lengths ........ 150 *Tait, Professor—Thermal Conductivity of Metals.......... 50 Chemistry. *Williamson, Prof. A. W.—Rccords of the Progress of Chemistry PI EHE WEE WAS oo ocn.ccs ele, Mh dhe, Oe She Ate ok ss ER hs 200 *Gladstone, Dr.—Chemical Constitution and Opieal Properties pimerssentte): OHs.).) 5: acuta: “Pa RTS Ae a ve ony 30 Brown, Professor Crum.—Temperature of Incandescent Bodies 50 Brown, Professor Crum.—Electric Tensions of Batteries .... 25 Geology. *Ramsay, Professor—Mapping Positions of Erratic Blocks and BRP PH CEC WIOE ) 5. 1s. %., 61564 airtel it ayy Bee» hye pate Senet 10 *Lyell, Sir C., Bart.—Kent’s Cavern Exploration .......... 150 Lubbock, Sir J.—Exploration of Settle Cave.............. 50 *Busk, Mr.—Fossil Elephants of Malta ...............05. 25 *Harkness, Professor.—Investigation of Fossil Corals........ 25 Carruthers, Mr.—Fossil Flora of Ireland ................ 20 *Harkness, Professor.—Collection of Fossils in the North-West MMPOG sf ccticiate Sosa oe cr. Cartels Ae ete wocate 10 *Bryce, Dr.—Earthquakes in Scotland................ 005. 2 Willett, Mr. H.—The Sub-Wealden Exploration .......... 25 Parpieds Poy ariiad sv hn Sts o4 teragrancienlgare crane a8 £1710 * Reappomted, jo i=) lx REPORT—1872. Biology. Brongit forward: ay. Bee oe slawhaweo ele vee vs £1710 OD Lane Fox, Col. A.—Forms of Instruction for Travellers .... 25 0 O *Stainton, Mr.—Record of the Progress of Zoology.......... 100 0 O *Christison, Sir R.—Antagonism of the Action of Poisons.... 20 0 0 *Balfour, Professor.—Effect of the Denudation of Timber on the Rainfall in North Britain (renewed) .............. 20 0 0 Mechanics. *Grantham, Mr. R. B.—-Treatment and Utilization of Sewage 100 0 0 *Froude, Mr. W.—Experiments on Instruments for Measuring the Speed of Ships and Currents (£30 renewed) ........ 50 * Reappointed. Place of Meeting in 1874. It was resolved that the Annual Meeting of the DESC Inaes in 1874 ke held at Belfast. GENERAL STATEMENT. lxi General Statement of Sums which have been paid on Account of Grants for Scientific Purposes. & s. d. 1834. Tide Discussions ....cosccserceeres 20 0 0 1835. Tide Discussions ........0.se000088 62 0 0 British Fossil Ichthyology ...... 105 0 0 £167 0 0 1836. Tide Discussions ......s.s0ees0eee 163 0 0 British Fossil Ichthyology ..... - 105 0 0 ‘Thermometric Observations, &c. 50 0 0 Experiments on long-continued MAU teevacavtscncsseacnacocassus) p épi chy O Rain-Gauges....cccccsssoscseveree 9 13 0 Refraction Experiments ........ 15 0 0 Lunar Nutation,..........0.s00004. 60 0 0 Thermometers ......,s00eeeee 15 6 0 £434 14° 0 1837. Tide Discussions .........see.s0e0e 284 1 0 Chemical Constants ..........0008. 2413 6 Lunar Nutation........cscesceseeee . 7 0 0 Observations on Waves............ 100 12 0 Tides at Bristol.....0..sssesseee ... 150 0 0 Meteorology and Subterranean ‘Temperature ..... Renaeasaacasenetarloo 0.40 Vitrification Experiments......... 150 0 0 Heart Experiments ........+. seeue pt fa eG Barometric Observations ......... 30 0 0 Barometers vesecesssccccseceseves « 1118 6 £918 14 6 1838. Tide Discussions .........6 seetise Dod. Ol British Fossil Fishes ....... «.. 100 0 0 Meteorological Observations and Anemometer (construction) ... 100 0 0 Cast Iron (Strength of) ......... 60 0 0 Animal and Vegetable Substances (Preservation of) ............... 19 1 10 Railway Constants .......... eee 41 12 10 Bristol Tides .........eeesseseee ances oD) 10) (0 Growth of Plants ...........0... 75 0 0 Mud in Rivers ........ Ree acesetacea 3.6 6 Lducation Committee ........0. 50 0 0 Heart Experiments ..... Sete steieette shes ds 0 Land and Sea Level....... aes Ser Uy | Subterranean Temperature ...... 8 6 0 Steam-vessels.....cssssssevesceceeees 100 0 0 Meteorological Committee ...... 31 9 5 Thermometers .....sccccessesseseee 16 4 0 £95612 2 1839. Fossil Ichthyology..........se00. 110 0 0 Meteorological Observations at Plymouth ..sccccerceseeesecerenee 63 10 0 Mechanism of Waves .,.+...... 144 2 0 Bristol Tides weesssssssersscverserree 35 18 6 £ s. a. Meteorology and Subterranean Temperature ......s0eseseeeeeeeee 21 11 0 Vitrification Experiments......... 9 4 7 Cast-Iron Experiments............ 100 0 0 Railway Constants ....00000.... 28 7 2 Land and Sea Level.........0... 274 1 4 Steam-vessels’ Engines........... 100 0 0 Stars in Histoire Céleste ......... 331 18 6 Stars in Lacaille ....scs0.0008 IL 0 0 Stars in R.A.S. Catalogue......... 6 16 6 Animal Secretions.,.....0...0..0 10 10 0 Steam-engines in Cornwall ...... 50 0 0 Atmospheric Air ....sssseceeeeeeee 16 1 0 Cast and Wrought Iron............ 40 0 0 Heat on Organic Bodies ......... 3 0 0 Gases on Solar Spectrum......... 22 0 0 Hourly Meteorological Observa- tions, Inverness and Kingussie 49 7 8 Fossil Reptiles ........ egeeveras ew 118 2 9 Mining Statistics ...cccccsceeeeeeee 50 0 0 £1595 11 0 1840. Bristol Tides .....sssecevssssereersee 100 0 0 Subterranean Temperature ...... 13.13 6 Heart Experiments ...scesseseeeee 18 19 0 Lungs Experiments ......60...00 $8 13 0 Tide Discussions ...,....se00e0 50 0 0 Land and Sea Level........... ieee as GRO Stars (Histoire Céleste) ......... 242 10 0 Stars (Lacaille) ...ccsssseesesessveee 415 0 Stars (Catalogue) ......... aaseteeae 0 Atmospheric Air ......4. 0 Water on Iron ......... Veespeccensas 10-09 0 Heat on Organic Bodies ......... 7 0 O Meteorological Observations.,.... 52 17 6 Foreign Scientific Memoirs ...,.. 112 1 6 Working Population............... 100 0 9 School Statistics......cecsseeeeeee . 50 0 0 Forms of Vessels ....cesesseesseees 184 7 0 Chemical and Electrical Pheno- MENG oe ccvcccccecesesecoees eevecee - 40 0 0 Meteorological Observations at Plymouth .........000- soeesessest 80): O):, 0 Magnetical Observations ......... 185 13 9 £1546 16 4 1841. Observations on Waves........... 80 0 0 Meteorology and Subterranean Temperature ..... daddoeverseorecnees ores. 10 Actinometers.....see+seees stacsecoea LOM ODIO0 Earthquake Shocks ............... 17 7 0 Acrid Poisons.............08 weeens cccnene Ome ORD. Veins and Absorbents .........008 3.0 0 Mud in Rivers .,.......c.cs00c00008 5 0 0 Marine Zoology......++« sedsdcceveoet LOOL21/8 Skeleton Maps ....cccccecseeeeseeee 20 0 O Mountain Barometers ........... 6 18 6 Stars (Histoire Céleste).....s.0006 185 0 0 Ixii REPortT—1872. ‘ F & Sd. Stars (Lacaille) ....ccsssssessseeseee 79 5 0 Stars (Nomenclature of) ......... 17 19 6 Stars (Catalogue of) .....s.sceeree - 40 0 0 Water oubiron) ...s..s<.0-.cene-eecs 50 0 0 Meteorological Qbservations at ERWWENTESS: . 5 Sseagecaess0sce0s nasrea ee DsO 0 Meteorological Observations (re- duction oF diz soecesdewssecenswes 20010); 90 Fossil Reptiles .....secseeees steers 50 0 0 Foreign Memoirs. .....ss0+..s00- o 62 0.0 Railway PECULONE! sys. 5 debesiweces.s tao nLeNG Forms of Vessels .....sseecsseseeses 193 12 0 Meteorological Observations at EER IVANGUth so.0.ccseculspesssaecoass 550 0 Magnetical Observations ......... 61 18 8 Fishes of the Old Red Sandstone 100 0 0 Tides at Leith ........ aNbestscataes 50 0 0 Anemometer at Edinburgh ...... 69 1 10 Tabulating Observations ....... 2 96 8 Races OfiMen: .s.ss..detevesseee.vco Do WOvelO Radiate Animals ...........000 2 0 0 £1235 10 11 1842, Dynamometric Instruments ...... beh 2) Anoplura Brifanniz ...........606 ~ 2 12 (0 Tides at Bristol.......... jactencseg TE RE (D) Gases on Light.........scceees seeetaoe 1aitail Chronometers ........... deeweeesee 26 17 6 Marine Zoology.....csccccsoscssense li 5 10 British Fossil Mammalia ......... 100 0 0 Statistics of Education .,.,...+.+ « 20 0 0 Marine Steam-vessels’ Engines... 28 0 0 Stars (Histoire Céleste)........... - 59 0 0 Stars (Brit. Assoc, Cat, of) ...... 110 0 0 Railway Sections .........s0000.... 161 10 0 British Belemnites...... Ere 33 Cy 50 0 0 Fossil Reptiles (publication of Report) .. prenbiesuseea dines 210 0 0 Forms of Vessels Waasiodcvevcerwases 180 0 0 Galvanic Experiments on Rocks 5 8 6 Meteorological Experiments at ELV MOUC, ssesenseennenasen ossnee O50" 0 Constant Indicator and Dynamo- metric Instruments ......... ow. 90 0 0 BiONCe Gh Wid .osses-scrssevenesess,..L000; 0 Vight on Growth of Seeds ...... 8 0 0 WATHUSCATISULSs cosnascesccereeac eed 50 0 0 Vegetative Power of Seeds ...... 8 1 11 Ripaiaog on Human Race ... ou giaty Liye 38 1843, Revision of the Nomenclature of Stars weeenecncas wanna Robes Reduction of Stars, British Asso- ciation Catalogue ....s..s.s0+6 Anomalous Tides, F ia of Forth Hourly Meteorological Observa- tionsat Kingussie and Inverness Meteorological Observations at Plymouth ..........e0000 ase ‘Whewell’s Meteorological Ane- mometer at Plymouth .....045. err ry oo £ 8. d. Meteorological Observations, Os- ler’s Anemometer at Plymouth 20 0 0 Reduction of Meteorological Ob- SETVALIONS ....sseeeeeeeees deswvassie 00! 20) 20 Meteorological Instruments and Gratuities: acncesenaqecennna aveaes O76. ' 0 Construction of Anemometer at INVertess) :f-cnecacsmecesecaeaten . 5612 2 Magnetic Codperation ........... 10 8 10 Meteorological Recorder for Kew Observatory .e...seeeeesees sasseeh TOU SOO Action of Gases on Light ......... 18 16 1 Establishment at Kew Observa- tory, Wages, Repairs, Furni- ture and Sundries ......... feces WOO Te Experiments by Captive Balloons 81 8 0 Oxidation of the Rails of Railways 20 0 0 Publication of Report on Fossil Repttlesicnsccossstecnstsessteseeeee 40 0 0 Coloured Drawings of "Railway Sactionsisstssseeeretenes ate eneeeeee 147 18 3 Registration’ ‘of Earthquake SHOCKS et. scsceccevevavaserare <- 150 ‘0570 Report on Zoological Nomencla- TUTE. Vena soseceresvorereceeeas pices LO Opa Uncovering Low wer Red Sand- stone near Manchester ........ - 4 4 6 Vegetative Power of Seeds ...... oD -o 8 Marine Testacea (Habits of ) 10° “0° 0 Marine Zoology..........4 vagsstyss. 0. OD Marine Zoology...sesssseereeereece 214 11 Preparation of Report on British Fossil Mammalia .........s0.000 100 0 0 Physiological Operations of Me- dicinal Agents ........- seeaieas ee 0) ital SEAtSteN “sencesccsereeece soem 36 5 8 Additional Experiments on the Forms of Vessels ...ssess+eoesee WO" 20.250 Additional Experiments on the Forms of Vessels .........+0+00. 100 0 0 Reduction of Experiments on the Forms of Vessels .s...seesseeeee 100 0 0 Morin’s Instrument and Constant Indicator’ 2.2... 0sssssas. Sess cups 69 14 10 een on the Strength of Materials) yo: cscseosedssseneshaeey 60 0 0 £1565 10 2 1844. Meteorological Observations at Kingussie and Inverness ...... 12 0 0 Completing Observations at Ply- i MNOULH ajasecoovecsWenienvesen can MoorenOu nO Magnetic and Meteorological Co- GPELALON. ceaeecudesesegeebsbsteen 25 8 4 Publication of the British ‘Aston ciation Catalogue of Stars...... 385 0 0 Observations on Tides on the East coast of Scotland ......... 100 0 0 Revision of the Nomenclature of : Stars ..sccscvcsnccsscsenees 142 9 2 9-9) 6 Maintaining the Establishmentin Kew Observatory seccoscsssseeee 117 17 8 Instruments for Kew Observatory 56 7 38 GENERAL STATEMENT. xii Influence of Light on Plants...... 10 Subterraneous Temperature in Treland ...ccssssesconvsseees yabarbrs /D Coloured Drawings of Railway Sections .rscoeccesscescecccceseee » 15 Investigation of Fossil Fishes of the Lower Tertiary Strata ... 100 Registering the Shocks of Earth- quakes. ss...cccssscoressernel 842 23 Structure of Fossil Shells ........- 20 Radiata and Mollusca of the /Egean and Red Seas......1842 100 Geographical Distributions of Marine Zoology ........+ 1842 10 Marine Zoology of Devon and Cornwall ...... Seeecsstecesh bees 10 Marine Zoology of Corfu ...... ee 10 Experiments on the Vitality of Seeds ...ccssessecccessevsceceesseee 9 Experiments on the Vitality of Seeds eecscessescsevseeee 11842 = 8 Exotic Anoplura ....secsesees Strength of Materials ...... Completing Experiments on the Forms of Ships ......... Wiecskese LOO Inquiries into Asphyxia .s....+++ 10 Investigations on the Internal Constitution of Metals ......... 50 Constant Indicator and Morin’s Instrument ..ccossveeeeee1842 10 £981 12 1845. Publication of the British Associa- tion Catalogue of Stars ......... 851 14 6 Meteorological Observations at Inverness ....sesccscsessereeeeene 30 Magnetic and Meteorological Co- OPEVAtiON sesesesseeseveeeseees vac AG Meteorological Instruments at Edinburgh ....ccsscovcssseessvveee 18 Reduction of Anemometrical Ob- servations at Plymouth ......... 25 Electrical Experiments at Kew Observatory ......e08. peiesisies we. 43 Maintaining the Establishment in Kew Observatory ...++++ Nested C4) For Kreil’s Barometrograph...... 25 Gases from Iron Furnaces ....., 50 The Actinograph ...... senseseens oo Le Microscopic Strueture of Shells 20 Exotic Anoplura .,..........1843 10 Vitality of Seeds J,..........1843 2 Vitality of Seeds ............1844 7 Marine Zoology of Cornwall ... 10 Physiological Action of Medicines 20 Statistics of Sickness and Mor- tality in WOrkos...tecesuacesecese | 20 Earthquake Shocks .........1843 15 14 £830 1846. British Association Catalogue of SATs ccaksvonyorsceweaelOs4 D110, - 0 Fossil Fishes of the London Civy 160 0 0, cooostSCcocococ[“( ao ooocoocoocu aoe & s d Computation of the Gaussian Constants for 1829 .,.... Srewane Oe 0 Maintaining the Establishment at Kew Observatory ...esseeseseeee 146 16 7 Strength of Materials ......... 60 0 0 Researches in Asphyxia ...... Pe Ie ie 4 Examination of Fossil Shells...... 10 0 0 Vitality of Seeds ...se0..00.1844 2 15 10 Vitality cf Seeds .ss.sseeeees 1845 712 8 Marine Zoology of Cornwall...... 10 0 0 Marine Zoology of Britaiu ...... 10 0 0 Exotic Anoplura ....se..eeee 1844 25 0 0 Expenses attending Anemometers 11 7 6 Anemometers’ Repairs .......+ qoseryrDonse (6 Atmospheric Waves .....+++ wees due 3.3 3 Captive Balloons ............1844 8 19 3 Varieties of the Human Race 1844 7 6 38 Statistics of Sickness and Mor- tality in York .iissecoscooceenee 12 0 0 £685 16 0 1847. Computation of the Gaussian Constants for 1829 ......04 scot “SOW ROLAO Habits of Marine Animals ...... 10 0 0 Physiological Action of Medicsnes 20 0 0 Marine Zoology of Cornwall...... 10 0 0 Atmospheric Waves ..+...sss+++ =i seaniees tp Vitality of Seeds ......... aspweb oath pattie 1C Maintaining the Establishment at Kew Observatory .ssseecseereeee 107 8 £208 5 4 1848. Maintaining the Establishment at Kew Observatory ...ecceeeeee-ee 171 15 11 Atmospheric Waves ...sessseseeees 310 9 Vitality of Seeds ..........0-0 ae 915 0 Completion of Cataloguesof Stars 70 0 0 On Colouring Matters ...... eee CSO? 0 On Growth of Plants......sess++0.+ 15 0 0 oor my 13 — 1849. Electrical Observations at Kew ObservatOry ..ccoccscccsecseceeee 50 0 0 Maintaining Establishment at AUR csecnas ane cenconeceneocenes oe 16 2 5 Vitality of Seeds ....eeceeeee sebyae Si el On Growth of Plants.........+0+0+ 5.0 0 Regiatration of Periodical Phe- TLOMENA oo scseceeessnererressnaners 10 0 0 Bill on account of Anemometrical Observations s.secersesrsseeee 13 9 #159 19 6 1850. Maintaining the Establishment at Kew Observatory ......-s+0+- woo Lo 0 Transit of Earthquake Waves... 50 0 0 Periodical Phenomena «......0. 15 0 0 Meteorological Instrument, i AZOTES» .ccasiversvsewvesyenassseenn ne a £345 18 0 | Or Ixiv REPORT—1872. £ os. d, 1851. Maintaining the Establishment at Kew Observatory (includes part of grantin 1849) .......sse0e00. 309 Theory of Heat .....ssseceeesecees se 620 Periodical Phenomena of Animals and Plants..... mtrsipeccrceeccesce | re Vitality of Seeds ..ssccssecscseeeee 5 Influence of Solar Radiation...... 30 Ethnological Inquiries .....0..0.6. 12 Researches on Annelida ,,....... 10 £391 1852. Maintaining the Establishment at Kew Observatory (including balance of grant for 1850) ... 233 17 Experiments on the Conduction OP TLCAL. .cvawvasnesssssoss sss seve Influence of Solar Radiations ete Le Geological Map of Ireland ...... 1 Researches on the British Anne- Vitality of Seeds of ee 10 Strength of Boiler Plates ......... 10 £304 1853. Maintaining the Establishment at Kew Observatory .......sesseeee 165 0 0 Experiments on tne Influence of Solar Radiation......ceccecceeeee 15 Researches on the Biitish Anne- A Gaaeercerieclst eaeleta cet se asisie'e'se esl 10 Dredging on the East Coast of Scotland......cessee. “Sa sanoubNcuct 10 Ethnological Queries ............ 5 £205 1854. Maintaining the Establishment at Kew Observatory (including balance of former grant) .. Investigations on Flax ........ tome fd Effects of Temperature on DVIRORERGITON , ssc.cascccccssoses 10 Registration of Periodical Phe- NOMENA ....ccreocrasconcescccssses 10 British Annelida ............000 - 10 Vitality of Seeds ....... wesenvepeca. ald Conduction of Heat .......... ssace 4 £380 1 1855. Maintaining the Establishment at Kew Observatory ...... sseveeeee 425 Earthquake Movements ......... 10 Physical Aspect of the Moon..... onan Vitality of Seeds .........000008 ~» 10 Map of the World....... suena nee » 15 Ethnological Queries..... 10. sss 5 Dredging near Belfast ........0... 4 £480 1 ee ne 1856, Maintaining the Establishment at Kew Observatory :-— 1854...... £75 0 0 2 1855......£500 0 a 575 = bo cloooao yaloocoork oO oo ojos veee 330 15 ecIiNnnose WH ORWN O° £ os. d. Strickland’s Ornithological Syno- NY MS “esccedecccccccccescevesccousc’ LOU sm Oma Dredging and Dredging Forms... 913 9 Chemical Action of Light ........ -- 20 0 0 Strength of Iron Plates ............ 10 0 0 Registration of Periodical Pheno- MENA sescessvessecscsvecsceessceeee 10 0 0 Propagation of Salmon ....0....... 10 0 0 £734 13 9 1857. Maintaining the Establishment at Kew Observatory ........ dyawene oO, Oe 10 Earthquake Wave Experiments... 40 0 0 Dredging near Belfast .......0+... 10 0 0 Dredging on the West Coast of scotland 3. ...ccesenus cneshidee'st 10 0 Investigations into the Mollusca of Califorma .ccsessebseushunets - 10 0 Experiments on Flax w.esecseeeee 5 0 Natural History of Madagascar.. 20 0 Researches on British Annelida 25 0 Report on Natural Products im- ported into Liverpool ..,...... 10 0 Artificial Propagation of Salmon 10 0 Temperature of Mines ............ 7 0 Thermometers for Subterranean Observations ...cccceesecesees oes, AnD 4 Life-Boats ...scccsserecsevsssaeseoees 5 0 £507 4 1858. Maintaining the Establishment at Kew Observatory .eocsccsesees -- 500 0 Earthquake Wave Experiments.. 25 0 Dredging on the West Coast of Scotland \secveresae Sessecanae vere hO! KOs a0 Dredging near Dublin ............ 5 0 0 Vitalityof Seeds). iccccimecsowes oO T TO Dredging near Belfast .......... sete LS NB), 12 Report on the British Annelida... 25 0 O Experiments .on the production of Heat by Motion in Fluids... 20 0 0 Report on the Natural Products imported into Scotland ,,..... sel OPO a) £618 18 2 1859. Maintaining the Establishment at Kew Observatory .......... esses 000 0 O Dredging near Dublin ........+... 15 0 0 Osteology of Birds,.........sseeeeee 50 0 0 Drish' (umiGatay cvecvape sc ssank oe ebe thea enee 25 EFOW ere sesnesss ante rendesAoods 50 0 O | Scottish Earthquakes eaareercriv en) =) Amy! Compounds............4.006+ 25 0 0 | Fauna, Devon and Cornwall .., 30 Electrical Standards............... 100 0 O | British Fossi] Corals..,............° 50 Malta Caves Exploration......... 30 0 0 | Bagshot Leaf-beds ...,.......... 50 Kent’s Hole Exploration ......... 200 0 O | Greenland Explorations ......... 100 Marine Fauna, &c., Devon and Fossil Flora ......... ehvisviscandpeemennl Gornwall se, ac.secsesss-paaadlerpe 25 0 0 | Tidal Observations ............... 100 Dredging Aberdeenshire Coast... 25 0 0 | Underground Temperature...... 50 Dredging Hebrides Coast........ - 50 0 0 | Spectroscopic investigations of Dredging the Mersey .........4.. 5 0 0 Animal Substances .........+++ 5 Resistance of Floating Bodies in Secondary Reptiles, &c. ...... ve 30 WAT OI: Sane gcsiasiisevessoce panera 50 0 O | British Marine Invertebrate Polycyanides of Organic Radi- AUN! -scssoscascnssreans ttepeeree Ag, Sa cs acagee) 2s Oponl) Rigor MOUS vr osedscncsgtncsemenane 10 0 0 Trish Annelida ...cciecesesenesdsens 15 0 0 1869, Catalogue of Crania............0+ 50 © 0 | Maintaining the Establishment Didine Birds of Mascarene Islands 50 .0 0 of Kew Observatory.........,.. 600 Typical Crania Researches ,..... 30 ® 0 | Lunar Commiittee.......ccccc00. 50 Palestine Exploration Fund.,..... 100 0 0 | Metrical Committce............00 25 ps Zoological Record............0e000e 100 acltihdaic soi Committee on Gases in Deep- 1867. Well Water... .scsascausesseene 25 Maintaining the Establishment BritishRainfally. cecoucve eure 50 of Kew Gbservatory...... ciekag 600 0 O°} Thermal Conductivity of Iron, Meteorological Instruments, Pa- EBs stas ses sapsieas acess eiaeabene 30 ABSCUH ES couitwamaacernpelensNedeceee 50 0 0] Kent’s Hole Explorations.,...,. 150 Lunar Committec......s:ereveeeeee- 120 0 © | Steamship Performances,..,..... 30 ooo coco coooo ooo como coeoo GENERAL STATEMENT. £ sd. Chemical Constitution of Cast Tron ...... Biaacease as sasiddettsie ene 80 0 0 Iron and Steel Manufacture ... 100 0 0 Methyl Series: .c..:....c..ccteesshs 30 0 0 Organic remains in Limestone Rocks......... Raccacied MaceNs sires tos 10 0 0 Earthquakes in Scotland......... 10 0 0 British Fossil Corals ............. 50 0 0 Bagshot Leaf-Beds ............+++ 30 0 0 Fossil Flora ...... aigeweestuarsdes vouch 20m OO Tidal Observations ............+++ 100 0 0 Underground Temperature ...... 30 0 0 Spectroscopic Investigations of Animal Substances ........... 5 0 0 Organic ACidS .......sceeeeeeeees 1250.10 Kiltorcan Fossils ............00000 20 0 0 Chemical Constitution and Phy- siological Action Relations ... 15 0 0 Mountain Limestone Fossils ...... 25 0 0 Utilization of Sewage ............ 10 0 0 Products of Digestion ..,.+....... 10 0 0 £1622 0 0 1870. Maintaining the Establishment of Kew Observatory ......ceeeseees 600 Metrical Committee .........s000. 29 Zoological Record .ss..e.e.e04--- 100 Committee on Marine Fauna ... 20 Bars in Fishes ......csseeeeseeevess 10 Chemical nature of Cast Iron... 80 Luminous Meteors ......ccceereee 30 Heat in the Blood ........eee0 15 British Rainfall............0eese0. 100 Thermal Conductivity ofIron&c. 20 British Fossil Corals.............., 50 Kent’s Hole Explorations ...... 150 Scottish Earthquakes ...,....00. 4 Bagshot Leaf-Beds sess 19 Fossil Flora ......ceseeeceeeee Reet ee Tidal Observations ........00... 100 Underground Temperature...... 50 Kiltorcan Quarries Fossils ...... 20 Mountain Limestone Fossils ... 25 Utilization of Sewage .........++. 50 Organic Chemical Compounds... 30 Onny River Sediment ........-++ 3 Mcchanical Equivalent of Heat 50 £1572 Sjocococoocoocooooooocecoceoce Slooooscooooocooooooceceocoocoo 1871. £ 8. d. Maintaining the Establishment of Kew Observatory ....++.--seseee 600 0 0 Monthly Reports of Progress in Chemistry ....0....000s.s0e. we 100 0 O Metrical Committee...... saeweue . 25 0 0 Zoological Record...... Scopicseennce 100 0 0 Thermal Equivalents of the Oxides of Chlorine ............ 10 0 0 Tidal Observations .......... .-- 100 0 0 Fossil Flora .........se000 neorrace erp) Laat} Luminous Meteors ..........+. . 30 0 0 British Fossil Corals,...........:.. 25 90 0 Heat in the Blood ,...........4+ 7 2 6 British Rainfall...... sesencacite's vrs md ue: 0 Kent’s Hole Explorations ...... 150 0 90 Fossil Crustacea ...escsseseseeeees 25 0 0 Methyl Compounds ....,....... «, 20 0 0 Lunar Objects ....+........ web esosie) 206, OLED Fossil Corals Sections, for Pho- tographing.......... Tavensecog thor 20 0 0 Bagshot Leaf-Beds ......... iaktees 20 0 0 Moab Explorations ......... saaes 100 0 0 Gaussian Constants ..,.........-. 40 0 0 £1472 2 6 1872. Maintaining the Establishment of Kew Observatory ....csesseesees 300 Metrical Committee............+++ 75 Zoological Record,......eceecserese 100 Tidal Committee ............ coves 200 Carbonifercus Corals ............ 25 Organic Chemical Compounds 25 Exploration of Moab ....-....... 100 Terato-Embryological Inquiries 10 Kent’s Cavern Exploration ..,... 100 Luminous Meteors ............66+ 20 Heat in the Blood ............... 15 Fossil Crustacea ........s0eeseeeee 25 Fossil Elephants of Malta ...... 25 Lunar Objects ..........se.sess0e. 20 Inverse Wave-Lengthis ............ 20 British Rainfall...............00000+ 100 Poisonous Substances Antago- NISHY setroeecccns ie sie)seasie od een BO Essential Oils, Chemical Consti- TUtION ; KClcencuneacetcuceeaews 40 Mathematical Tables ............ 50 Thermal Conductivity of Metals 25 £1285 o|;ooo (—) ocooococeocococococoo cloco o coooocqccoeoqcocececo Ixvili REPORT—1872. General Meetings. On Wednesday Evening, August 14, at 8 p.a., in the Dome, Professor Sir William Thomson, LL.D., F.R.S., President, resigned the office of President to Dr. W. B. Carpenter, LL.D., F.R.S., who took the Chair, and delivered an Address, for which see page Lxix. On Thursday Evening, August 15, at 8 p.m., a Soirée took place in the Dome, Corn Exchange, and Museum. , On Friday Evening, August 16, at 8.30 p.m., in the Dome, Professor P. Martin Duncan, M.D., F.R.S., delivered a Discourse on “ Insect Metamor- phosis.” On Saturday Evening, at 8 p.m., in the Dome, William Spottiswoode, LL.D., F.R.S., delivered a Discourse entitled “Sunshine, Sea, and Sky,” to the Operative Classes of Brighton. ; On Monday Evening, August 19, at 8.30 p.., in the Dome, Prof. W. K. Clifford delivered a Discourse on “The Aims and Instruments of Scientific Thought.” _ . On Tuesday Evening, August 20, at 8 p.w., a Soirée took place in the Dome, Corn Exchange, and Museum. On Wednesday, August 21, at 2.30 p.a., the concluding General Meeting took place, when the Proceedings of the General Committee, and the Grants of Money for Scientific purposes, were explained to the Members. » The Meeting was then adjourned to Bradford*, * The Meeting is appointed to take place on Wednesday, September 17, 1873. ADDRESS OF WILLIAM B. CARPENTER, M.D., LL.D., F.RBS,, PRESIDENT, My Lorps, Lapres, anp GENTLEMEN, Turrty-stx years have now elapsed since at the first and (I regret to say) the only Meeting of this Association held in Bristol,—which Ancient City followed immediately upon our National Universities in giving it a welcome, —I enjoyed the privilege which I hold it one of the most valuable functions of these Annual assemblages to bestow ; that of coming into personal relation with those distinguished Men whose names are to every cultivator of Science as “household words,” and the light of whose brilliant example, and the warmth of whose cordial encouragement are the most precious influences by which his own aspirations can be fostered and directed. Under the Presi- dency of the Marquis of Lansdowne, with Conybeare and Prichard as Vice- Presidents, with Vernon Harcourt as General Secretary, and John Phillips as Assistant Secretary, were gathered together Whewell and Peacock, James Forbes and Sir W. Rowan Hamilton, Murchison and Sedgwick, Buckland and De la Beche, Henslow and Daubeny, Roget, Richardson, and Edward Forbes, with many others, perhaps not less distinguished, of whom my own recollec- tion is less vivid. : In his honoured old age, Sedgwick still retains, in the Academic home of his life, all his pristine interest in whatever bears on the advance of the Science he has adorned as well as enriched; and Phillips still cultivates with all his old enthusiasm the congenial soil to which he has been trans- planted. But the rest,—our fathers and elder brothers,—‘*‘ Where are they?” It is for us of the present generation to show that they live in our lives; to carry forward the work which they commenced; and to transmit the influence of their example to our own successors. There is one of these great men, whose departure from among us since last we met claims a special notice, and whose life—full as it was of years and honours—ve should have all desired to see prolonged for a few months, could its feebleness have been unattended with suffering. For we should all then have sympathized with Murchison, in the delight with which he would have received the intelligence of the safety of the friend in whose scientific labours and personal welfare he felt to the last the keenest interest. That this in- telligence, which our own Expedition for the relief of Livingstone would have lxx REPORT—1872. obtained (we will hope) a few months later, should have been brought to us through the generosity of one, and the enterprising ability—may I not use our peculiarly English word, the “pluck ”—of another of our American brethren, cannot but be a matter of national regret to us. But let us bury that regret in the common joy which both Nations feel in the result; and while we give a cordial welcome to Mr. Stanley, let us glory in the prospect now opening, that England and America will co-operate in that noble object which—far more than the discovery of the Sources of the Nile—our great Traveller has set before himself as his true mission, the Extinction of the Slave Trade. At the last Meeting of this Association, I had the pleasure of being able to announce, that I had received from the First Lord of the Admiralty a favourable reply to a representation I had ventured to make to him, as to the importance of prosecuting on a more extended scale the course of inquiry into the Physical and Biological conditions of the Deep Sea, on which, with my colleagues Prof. Wyville Thomson and Mr. J. Gwyn Jeffreys, I had been engaged for the three preceding years. That for which I had asked was a Circumnavigating Expedition of at least three years’ duration, provided with an adequate Scientific Staff, and with the most complete Equipment that our experience could devise. The Council of the Royal Society haying been led by the encouraging tenor of the answer I had received, to make a formal Application to this effect, the liberal arrangements of the Go- vernment have been carried out under the advice of a Scientific Com- mittee which included Representatives of this Association. H. M. ship ‘Challenger,’ a vessel in eyery way suitable for the purpose, is now being fitted out at Sheerness; the Command of the Expedition is intrusted to Captain Nares, an Officer of whose high qualifications I have myself the fullest assurance; while the Scientific charge of it will be taken by my excellent friend Prof. Wyville Thomson, at whose suggestion it was that these investigations were originally commenced, and whose zeal for the efficient prosecution of them is shown by his relinquishment for a time of the important Academic position he at present fills. It is anticipated that the Expedition will sail in November next; and I feel sure that the good wishes of all of you will go along with it. The confident anticipation expressed by my predecessor, that for the utili- zation of the total Eclipse of the Sun then impending, our Government would “exercise the same wise liberality as heretofore in the interests of Science,” has been amply fulfilled. An Kclipse-Expedition to India was organized at the charge of the Home Government, and placed under the direction of Mr. Lockyer ; the Indian Government contributed its quota to the work; anda most valuable body of results was obtained, of which, with those of the pre- vious year, a Report is now being prepared under the direction of the Council of the Astronomical Society. It has been customary with successive occupants of this Chair, distin- guished as Leaders in their several divisions of the noble Army of Science, to open the proceedings of the Meetings over which they respectively presided, with a Discourse on some aspect of Nature in her Relation to Man. But J am not aware that any one of them has taken up the other side of the inquiry,—that which concerns Man as the “Interpreter of Nature ;” and I have therefore thought it not inappropriate to lead you to the con- sideration of the Mental processes, by which are formed those fundamental conceptions of Matter and Force, of Cause and Effect, of Law and Order, which furnish the basis of all scientific reasoning, and constitute the Phi- ADDRESS. lxxi losophia prima of Bacon. There is a great deal of what I cannot but regard as fallacious and misleading Philosophy—‘* oppositions of Science falsely so called””—abroad in the world at the present time. And I hope to satisfy you, that those who set up their own conceptions of the Orderly Sequence which they discern in the Phenomena of Nature, as fixed and determinate Laws, by which those phenomena not only are within all Human expe- rience, but always have been, and always must be, invariably governed, are really guilty of the Intellectual arrogance they condemn in the Systems of the Ancients, and place themselves in diametrical antagonism to those real Philosophers, by whose comprehensive grasp and penetrating insight that Order has been so far disclosed. For what love of the Truth as it is in Nature was ever more conspicuous, than that which Kepler displayed, in his abandonment of each of the ingenious conceptions of the Planetary System which his fertile Imagination had successively devised, so soon as it proved to be inconsistent with the facts disclosed by observation? In that almost admiring description of the way in which his enemy Mars, “whom he had left at home a despised Captive,” had “ burst all the chains of the equations, and broke forth from the prisons of the tables,” who does not recognize the justice of Schiller’s definition of the real Philosopher, as one who always loves Truth better than his System? And when at last he had gained the full assurance of a success so complete that (as he says) he thought he must be dreaming, or that he had been reasoning in a circle, who does not feel the almost sublimity of the self-abnegation, with which, after attaining what was in his own estimation such a glorious reward of his life of toil, dis- appointment, and self-sacrifice, he abstains from claiming the applause of his contemporaries, but leaves his fame to after ages in these noble words : «The book is written; to be read either now or by posterity, I care not « which. It may well wait a century for a reader, as God has waited six « thousand years for an observer.” And when a yet greater than Kepler was bringing to its final issue that grandest of all Scientific Conceptions, long pondered over by his almost superhuman intellect,—which linked together the Heavens and the Earth, the Planets and the Sun, the Primaries and_ their Satellites, and included even the vagrant Comets, in the newus of a Universal Attraction— establishing for all time the truth for whose utterance Galileo had been con- demned, and giving to Kepler’s Laws a significance of which their author had never dreamed,—what was the meaning of that agitation which prevented the Philosopher from completing his computation, and compelled him to hand it over to his friend? ‘That it was not the thought of his own greatness, but the glimpse of the grand Universal Order thus revealed to his mental vision, which shook the serene and massive soul of Newton to its founda- tions, we have the proof in that beautiful comparison in which he likened himself to a Child picking up shells on the shore of the vast Ocean of Truth ; —a comparison which will be evidence to all time at once of his true Phi- losophy and of his profound Humility. Though it is with the Intellectual Representation of Nature which we call Science, that we are primarily concerned, it will not be without its use to cast a glance in the first instance at the other two principal characters under which Man acts as her Interpreter,—those, namely, of the Artist and of the Poet. The Artist serves as the Interpreter of Nature, not when he works as the mere copyist, delineating that which he sees with his bodily eyes, and which we could see as well for ourselves ; but when he endeavours to awaken within Ixxii REPORT—1872. us the perception of those beauties and harmonies which his own trained” sense has recognized, and thus impart to us the pleasure he has himself derived from their contemplation. As no two Artists agree in the original constitu- tion and acquired habits of their Minds, all look at Nature with different (mental) eyes; so that to each, Nature is what he individually sees wn her. The Poet, again, serves as the Interpreter of Nature, not so much when by skilful word-painting (whether in prose or verse) he calls up before our mental vision the picture of some actual or ideal scene, however beautiful ; as when, by rendering into appropriate forms those deeper impressions made by the Nature around him on the Moral and Emotional part of his own Nature, he transfers these impressions to the corresponding part of ours. For it is the attribute of the true Poet to penetrate the secret of those mys- terious influences which we all unknowingly experience; and haying dis- covered this to himself, to bring others, by the power he thus wields, into the like sympathetic relation with Nature,—evoking with skilful touch the varied response of the Soul’s finest chords, heightening its joys, assuaging its griefs, and elevating its aspirations. Whilst, then, the Artist aims to picture what he sces in Nature, it is the object of the Poet to represent what he feels in Nature; and to each true Poet, Nature is what he individually Jjinds in her. The Philosopher’s interpretation of Nature scems less individual than that of the Artist or the Poet, because it is based on facts which any one may verify, and is elaborated by reasoning processes of which all admit the validity. He looks at the Uniyerse as a vast Book lying open before him, of which he has in the first place to learn the characters, then to master the language, and finally to apprehend the ideas which that language conveys. In that Book there are many Chapters, treating of different subjects; and as Life is too short for any one man to grasp the whole, the Scientific interpretation of this Book comes to be the work of many Intellects, differing not merely in. the range but also in the character of their powers. But whilst there are “diversities of gifts,” there is “ the same spirit.” While each takes his special direction, the general Method of study is the same for all. And it is a testimony alike to the truth of that Method and to the Unity of Nature, that there is an ever-increasing tendency towards agreement among those who use it aright ;—temporary differences of interpretation being removed, sometimes by a more complete mastery of her language, sometimes by a better appre- hension of her ideas ;—and lines of pursuit which had seemed entirely distinct or even widely divergent, being found to lead at last to one common goal, And it is this agreement which gives rise to the general belief—in many, to the confident assurance—that the Scientific interpretation of Nature represents her not merely as she seems, but as she really is. But when we carefully examine the foundation of that assurance, we find reason to distrust its security; for it can be shown to be no less true of the Scientific conception of Nature, than it is of the Artistic or the Poetic, that it isa representation framed by the Mind itself out of the materials supplied by the impressions which external objects make upon the Senses ; so that to each Man of Science, Nature is what he individually believes her to be. And that belief will rest on very different bases, and will have very unequal values, in different departments of Science—Thus in what are commonly known as the “exact” Sciences, of which Astronomy may be taken as the type, the data afforded by precise methods of observation can be made the basis of reasoning, in every step of which the Mathematician feels the fullest assurance of certainty ; and the final deduction is justified either by ADDRESS. lxxili its conformity to known or ascertainable facts,—as when Kepler determined the elliptic orbit of Mars; or by the fulfilment of the predictions it has sanctioned,—as in the occurrence of an Eclipse or an Occultation at the precise moment specified many years previously ; or, still more emphatically, by the actual discovery of phenomena till then unrecognized,—as when the ° Perturbations of the planets, shown by Newton to be the necessary results of their mutual attraction, were proved by observation to have a real existence ; or as when the unknown disturber of Uranus was found in the place assigned to him by the computations of Adams and Le Verrier. We are accustomed, and I think most rightly, to speak of these achieve- ments as triumphs of the Human Intellect. But the very phrase implies that the work is done by Mental Agency. And even in the very first stage of the process—the interpretation of observations—there is often a liability to serious error. Of this we have a most noteworthy example in the fact that the esti- mated distance of the Earth from the Sun, deduced from observations of the last Transit of Venus, is now pretty certainly known to be about three millions of miles too great; the strong indications of such an excess afforded by the nearly coincident results of other modes of inquiry haying led to a reexamination of the record, which was found, when fairly interpreted, fully to justify—if not even to require—the reduction. Even the veri- fication of the prediction is far from proving the Intellectual process by which it was made to have been correct. For we learn from the honest confessions of Kepler, that he was led to the discovery of the Elliptic orbit of Mars by a series of happy accidents, which turned his erroneous guesses into the right direction; and to that of the passage of the Radius Vector over equal areas in equal times, by the notion of a whirling force emanating from the Sun, which we now regard as an entirely wrong conception of the cause of orbital revolution *. It should always be remembered, moreover, that the Ptolemaic system of Astronomy, with all its cumbrous ideal mechanism of “ Centric and Excentric, Cycle and Epicycle, Orb in Orb,” did intellectually represent all that the Astronomer, prior to the invention of the Telescope, could sce from his actual standpoint, the Karth, with an accuracy which was proved by the fulfilment of his predictions. And in that last and most memorable anticipation which has given an imperishable fame to our two illustrious contemporaries, the inadequacy of the basis afforded by actual observation of the perturbations of Uranus, required that it should be supplemented by an assumption of the probable distance of the disturbing Planet beyond, which has been shown by subsequent observation to have been only an approximation to the truth. Even in this most exact of Sciences, therefore, we cannot proceed a step, without translating the actual Phenomena of Nature into Intellectual Repre- sentations of those phenomena; and it is because the Newtonian conception is not only the most simple, but is also, up to the extent of our present knowledge, universal in its conformity to the facts of observation, that we accept it as the only Scheme of the Universe yet promulgated, which satisfies our Intellectual requirements. When, under the reign of the Ptolemaic System, any new inequality was discovered in the motion of a Planet, a new wheel had to be added to the ideal Mechanism,—as Ptolemy said, “‘to save appearances.” If it should prove, a century hence, that the motion of Neptune himself is disturbed by some other attraction than that exerted by the interior Planets, we should confidently expect that not an deal but a real cause for that dis- turbance will be found in the existence of another Planet beyond. But _ * See Drinkwater’s ‘ Life of Kepler,’ in the Library of Useful Knowledge, pp. 26-35. Ixxiv REPORT—1872, I trust that I have now made it evident to you, that this confident expectation is not justified by any absolute necessity of Nature, but arises entirely out of ow: belief in her Uniformity; and into the grounds of this and other Primary Beliefs, which serve as the foundation of all Scientific reasoning, we shall presently inquire. There is another class of cases, in which an equal certainty is generally claimed for conclusions that seem to flow immediately from observed facts, though really evolved by Intellectual processes ; the apparent simplicity and directness of those processes either causing them to be entirely overlooked, or veiling the assumptions on which they are based.—Thus Mr. Lockyer speaks as confidently of the Sun’s Chromosphere of incandescent Hydro- gen, and of the local outbursts which cause it to send forth projections tens of thousands of miles high, as if he had been able to capture a flask of this gas, and had generated water by causing it to unite with oxygen. Yet this confidence is entirely based on the assumption, that a certain line which is seen in the Spectrum of a hydrogen flame, means hydrogen also when seen in the spectrum of the Sun’s chromosphere; and high as is the probability of that assumption, it cannot be regarded as a demonstrated certainty, since it is by no means inconceivable that the same line might be produced by some other substance at present unknown.—And so when Dr, Huggins deduces from the different relative positions of certain lines in the spectra of different Stars, that these Stars are moving from or towards us in space, his admirable train of reasoning is based on the assumption that these lines have the same meaning —that is, that they represent the same elements—in every luminary. That assumption, like the preceding, may be regarded as possessing a sufficiently high probability to justify the reasoning based upon it; more especially since, by the other researches of that excellent observer, the same Chemical elements have been detected as vapours in those filmy cloudlets which seem to be stars in an early stage of consolidation. But when Frankland and Lockyer, seeing in the spectrum of the yellow Solar prominences a certain bright line not identifiable with that of any known Terrestrial flame, attri- bute this to a hypothetical new substance which they propose to call Helium, it is obvious that their assumption rests on a far less secure foundation ; until it shall have received that verification, which, in the case of Mr. Crookes’s researches on Thallium, was afforded by the actual discovery of the new metal, whose presence had been indicated to him by a line in the Spectrum not attributable to any substance then known. In a large number of other cases, moreover, our Scientific interpretations are clearly matters of judgment; and this is eminently a personal act, the value of its results depending in each case upon the qualifications of the individual for arriving at a correct decision. The surest of such judgments are those dictated by what we term ‘Common Sense,” as to matters on which there seems no room for difference of opinion, because every sane person comes to the same conclusion, although he may be able to give no other reason for it than that it appears to him “self-evident.” Thus while Philosophers have raised a thick cloud of dust in the discussion of the basis of our belief in the oxistence of a World external to ourselyes,—of the Non Ego, as distinct from the Ego,—and while every Logician claims to have found some flaw in the proof advanced by every other,—the Common Sense of Mankind has arrived at a decision that is practically worth all the arguments of all the Philosophers who have fought again and again over this battle- ground. And I think it can be shown that the trustworthiness of this Common Sense decision arises from its dependence, not on any one set of ADDRESS. Ixxv. Experiences, but upon owr unconscious co-ordination of the whole aggregate of our Experiences,—not on the conclusiveness of any one train of Reasoning, but on the convergence of all our lines of thought towards this one centre. Now this “‘ Common Sense,” disciplined and enlarged by appropriate culture, becomes one of our most valuable instruments of Scientific inquiry ; affording in many instances the best, and sometimes the only, basis for a rational con- clusion. Let us take as a typical case, in which no special knowledge is required, what we are accustomed to call the “ flint implements” of the Abbeville and Amiens gravel-beds. No logical proof can be adduced that _ the peculiar shapes of these flints were given to them by Human hands; but does any unprejudiced person now doubt it? The evidence of design, to which, after an examination of one or two such specimens, we should only be justified in attaching a probable value, derives an irresistible cogency from accumulation. On the other hand, the improbability that these flints acquired their peculiar shape by accident, becomes to our minds greater and greater as more and more such specimens are found; until at last this hypothesis, although it cannot be directly disproved, is felt to be almost in- conceivable, except by minds previously ‘“ possessed ” by the ‘‘ dominant idea ” of the modern origin of Man. And thus what was in the first instance a matter of discussion, has now become one of those “ self-evident ” propositions, which claim the unhesitating assent of all whose opinion on the subject is entitled to the least weight. We proceed upwards, however, from such questions as the Common Sense of Mankind generally is competent to decide, to those in which special know- ledge is required to give value to the judgment; and thus the interpretation of Nature by the use of that faculty comes to be more and more individual ; things being perfectly “self-evident” to men of special culture, which ordi- nary men, or men whose training has lain in a different direction, do not apprehend as such. Of all departments of Science, Geology seems to me to be the one that most depends on this specially-trained “Common Sense ;” which brings as it were into one focus the light afforded by a great variety of studies,—Physical and Chemical, Geographical and Biological ; and throws it on the pages of that Great Stone Book, on which the past history of our Globe is recorded. And whilst Astronomy is of all Sciences that which may be considered as most nearly representing Nature as she really is, Geology is that which most completely represents her as seen through the medium of the interpreting mind; the meaning of the phenomena that constitute its data being in almost every instance open to question, and the judgments passed upon the same facts being often different according to the qualifications of the several judges. No one who has even a general acquaintance with the history of this department of Science, can fail to see that the Geology of each epoch has been the reflection of the Minds by which its study was then directed ; and that its true progress dates from the time when that “‘Common Sense ” method of interpretation came to be generally adopted, which consists in seeking the explanation of past changes in the Forces at present: in operation, instead of invoking the aid of extraordinary and mysterious agencies, as the older Geologists were wont to do, whenever they wanted—like the Ptolemaic Astronomers— to save appearances.” The whole tendency of the ever-widening range of modern Geological inquiry has been to show how little reliance can be placed upon the so-called “Laws” of Stratigraphical and Paleontological Succession, and how much allowance has to be made for local conditions. So that while the Astro- nomer is constantly enabled to point to the fulfilment of his predictions as an Ixxvi REPORT—1872. evidence of the correctness of his method, the Geologist is almost entirely destitute of any such means of verification. For the value of any prediction that he may hazard—as in regard to the existence or non-existence of Coal in any given area,—depends not only upon the truth of the general doctrines of Geology in regard to the succession of Stratified Deposits, but still more upon the detailed knowledge which he may have acquired of the distribution of those Deposits in the particular locality. Hence no reasonably-judging man would discredit either the general doctrines or the methods of Geology, because the prediction proves untrue in such a case as that now about to be brought in this neighbourhood to the trial of experience. We have thus considered Man’s function as the Scientific Interpreter of Nature in two departments of Natural Knowledge ; one of which affords an example of the strictest, and the other of the freest method, which Man can employ in constructing his Intellectual representation of the Universe. And as it would be found that in the study of all other departments the same methods are used, either separately or in combination, we may pass at once to an- other part of our inquiry. The whole fabric of Geometry rests upon certain Axioms which every one accepts as true, but of which it is necessary that the truth should be assumed, because they are incapable of demonstration. So, too, the deliverances of our “Common Sense” derive their trustworthiness from what we consider the “‘ self-evidence ’ of the propositions affirmed. There are, then, certain. Primary Beliefs, which constitute the groundwork of all Scientific reasoning ; and we have next to inquire into their origin. This inquiry brings us face to face with one of the great Philosophical problems of our day, which has been discussed by Logicians and Meta- physicians of the very highest ability as Leaders of opposing Schools, with the one result of showing how much can be said on each side. By the Intuitionalists it is asserted that the tendency to form these Primary Beliefs is inborn in Man, an original part of his mental organization ; so that they grow up spontaneously in his Mind as its faculties are gradually unfolded and developed, requiring no other Experience for their genesis, than that which suffices to call these faculties into exercise. But by the advocates of the doctrine which regards Ewperience as the basis of all our knowledge, it is maintained that the Primary Beliefs of each individual are nothing else than generalizations which he forms of such experiences as he has either himself acquired or has consciously learned from others; and they deny that there is any original or intuitive tendency to the formation of such beliefs, beyond that which consists in the power of retaining and generalizing experiences. I have not introduced this subject with any idea of placing before you even a summary of the ingenious arguments by which these opposing doctrines have been respectively supported; nor should I have touched on the question at all, if I did not believe that a means of reconcilement between them can be found in the idea, that the Intellectual Intuitions of any one Generation are the embodied Experiences of the previous Race. For, as it appears to me, there has been a progressive improvement in the Thinking Power of Man; every product of the culture which has preceded serving to prepare the soil for yet more abundant harvests in the future. Now, as there can be no doubt of the Hereditary transmission in Man of acquired constitutional peculiarities, which manifest themselves alike in tendencies to Bodily and to Mental disease, so it seems equally certain that acquired mental habitudes often impress themselves on his organization, with ADDRESS Ixxvil sufficient force and permanence to occasion their transmission to the offspring as tendencies to similar modes of thought. And thus, while all admit that Knowledge cannot thus descend from one generation to another, an increased aptitude for the acquirement, either of knowledge generally, or of some par- ticular kind of it, may be thus inherited. These tendencies and aptitudes _ will acquire additional strength, expansion, and permanence, in each new _ generation, from their habitual exercise upon the materials supplied by a con- tinually enlarged experience ; and thus the acquired habitudes produced by the Intellectual culture of ages, will become “a second nature ’’ to every one who inherits them *. We have an illustration of this progress in the fact of continual occurrence, that conceptions which prove inadmissible to the minds of one generation, in consequence either of their want of intellectual power to apprehend them, or of their preoccupation by older habits of thought, subsequently find a uni- versal acceptance, and even come to be approved as “self-evident.” Thus the First Law of Motion, divined by the genius of Newton, though opposed by many Philosophers of his time as contrary to all experience, is now accepted by common consent, not merely as a legitimate inference from Experiment, but as the expression of a necessary and universal truth; and the same Axiomatic value is extended to the still more general doctrine, that Energy of any kind, whether manifested in the “ molar” motion of masses, or con- sisting in the “molecular” motion of atoms, mus¢ continue under some form or other without abatement or decay; what all admit in regard to the indestructibility of Matter, being accepted as no less true of Force, namely, that as ex nihilo nil fit, so nil fit ad mhilum t. - But, it may be urged, the very conception of these and similar great truths is in itself a typical example of Intuition. The men who divined and enun- ciated them stand out above their fellows, as possessed of a Genius which could not only combine but create, of an Insight which could clearly discern what Reason could but dimly shadow forth. Granting this freely, I think it may be shown that the Intuitions of individual Genius are but specially exalted forms of endowments which are the general property of the Race at the time, and which have come to be so in virtue of its whole previous culture.— Who, for example, could refuse to the marvellous aptitude for perceiving the relations of Numbers, which displayed itself in the untutored boyhood of George Bidder and Zerah Colburn, the title of an Intuitive gift? But who, on the other hand, can believe that a Bidder or a Colburn could suddenly * This doctrine was first explicitly put forth by Mr. Herbert Spencer; in whose Philosophical Treatises it will be found most ably developed. I am glad to be able to append the following extract from a letter which Mr. John Mill, the great Master of the Experiential School, was good enough to write to me a few months since, with reference to the attempt I had made to place ‘Common Sense” upon this basis (Contemporary Review, Feb. 1872) :—‘‘ When states of mind in no respect innate or instinctive have been # frequently repeated, the mind acquires, as is proved by the power of Habit, a greatly “ inereased facility of passing into those states; and this increased facility must be owing “to some change of a physical character in the organic action of the Brain. There is also “‘considerable evidence that such acquired facilities of passing into certain modes of “ cerebral action can in many cases be transmitted, more or less completely, by inheritance, « The limits of this power of transmission, and the conditions on which it depends, are a “ subject now fairly before the scientific world ; and we shall doubtless in time know much “ more about them than we do now. But so far as my imperfect knowledge of the subject “ qualifies me to have an opinion, I take much the same view of it that you do, at least _ “in principle.” + This is the form in which the doctrine now known as that of the ‘Conservation of Energy” was enunciated by Dr. Mayer, in the very remarkable Essay published by him in 1845, entitled ‘« Die organische Bewegung in ihrem Zusammenhange mit dem Stoffwechsel,” Ixxvili REPORT—1872. arise in a race of Savages who cannot count beyond five? Or, again, in the history of the very earliest years of Mozart, who can fail to recognize the dawn of that glorious Genius, whose brilliant but brief career left its im- perishable impress on the Art it enriched? But who would be bold enough to affirm that an infant Mozart could be born amongst a tribe, whose only musical instrument is a tom-tom, whose only song is a monotonous chant ?’ Again, by tracing the gradual genesis of some of those Ideas which we now accept as ‘self-evident,”—such, for example, as that of the ‘ Uniformity of Nature ”—we are able to recognize them as the expressions of certain Intel- lectual tendencies, which have progressively augmented in force in successive generations, and now manifest themselves as acquired Mental Instincts that penetrate and direct our ordinary course of Thought. Such Instincts constitute a precious heritage, which has been transmitted to us with ever-increasing. value through the long succession of preceding generations; and which it is for us to transmit to those who shall come after us, with all that further in- crease which our higher Culture and wider range of Knowledge can impart. And now, having studied the working action of the Human Intellect in the Scientific Interpretation of Nature, we shall examine the general character of its products ; and the first of these with which we shall deal is our con- ception of Matter and of its relation to Force. The Psychologist of the present day views Matter entirely through the light of his own Consciousness: his idea of Matter in the abstract being that it is a something” which has a permanent power of exciting Sensations ; his idea of any “ property” of Matter being the mental representation of some kind of sensory impression he has received from it; and his idea of any particular kind of Matter being the representation of the whole aggregate of the Sense-perceptions which its presence has called up in his Mind. Thus when I press my hand against this table, I recognize its unyieldingness through the conjoint medium of my sense of Touch, my Muscular sense, and my Mental sense of Effort, to which it will be convenient to give the general designation of the Tactile Sense; and I attribute to that table a hardness which resists the effort I make to press my hand into its substance, whilst I also recognize the fact that the force I have employed is not sufficient to move its mass. But I press my hand against a lump of dough ; and finding that its substance yields under my pressure, I call it soft. Or again, I press my hand against this desk ; and I find that although I do not thereby change its form, I change its place ; andso I get the Tactile idea of Motion. Again, by the impressions received through the same Sensorial apparatus, when I lift this book in my hand, I am led to attach to it the notion of weight or ponderosity ; and by lifting different solids of about the same size, I am enabled, by the different degrees of exertion I find myself obliged to make in order to sustain them, to distinguish some of them as light, and others as heavy. Through the medium of another set of Sense- perceptions which some regard as belonging to a different category, we dis- tinguish between bodies that feel “ hot” and those that feel “cold;” and in this manner we arrive at the notion of differences of Temperature. And it is through the medium of our Tactile Sense, without any aid from Vision, that we first gain the idea of solid form, or the Three Dimensions of Space. Again, by the extension of our Tactile experiences, we acquire the notion of liquids, as forms of matter yielding readily to pressure, but possessing’ a sensible weight which may equal that of solids: and of air, whose resisting power is much slighter, and whose weight is so small that it can only be made sensible by artificial means, Thus, then, we arrive at the notions of ADDRESS. Ixxix resistance and of weight as properties common to all forms of Matter; and now that we have got rid of that idea of Light and Heat, Electricity and Magnetism, as “imponderable fluids,” Which used to vex our souls in our Scientific Childhood, and of which the popular term “ Electric fluid” is a “survival,” we accept these properties as affording the practical distinction between the “ material” and the “immaterial.” Turning, now, to that other great portal of Sensation, the Sight, through which we receive most of the messages sent to us from the Universe around, we recognize the same truth. Thus it is agreed alike by Physicists and Physiologists, that Colowr does not exist as such in the object itself; which has merely the power of reflecting or transmitting a certain number of millions of undulations in a second; and these only produce that affection of our consciousness which we call Colour, when they fall upon the retina of the living Percipient. And if there be that defect either in the retina or in the apparatus behind it, which we call “colour-blindness” or Daltonism, some particular hues cannot be distinguished, or there may even be no power of distinguishing any colour whatever. If we were all like Dalton, we should see no difference, except in form, between ripe cherries hanging on a tree, and the green leaves around them: if we were all affected with the severest form of colour-blindness, the fair face of Nature would be seen by us as in the chiaroscuro of an Engraving of one of Turner’s Landscapes, not as in the glowing hues of the wondrous Picture itself. And in regard to our Visual conceptions it may be stated with perfect certainty, as the result of very numerous observations made upon persons who have acquired sight for the first time, that these do not serve for the recognition even of those objects with which the individual had become most familiar through the Touch, until the two sets of Sense-perceptions have been co-ordinated by experience*, When once this co-ordination has been effected, however, the composite perception of Form which we derive from the Visual sense alone is so complete, that we seldom require to fall back upon the Touch for any further information respecting that quality of the object——Sc, again, while it is from the co-ordination of the two dissimilar pictures formed by any solid or projecting object upon our two retine, that (as Sir Charles Wheat- stone’s admirable investigations have shown) we ordinarily derive through the Sight alone a correct notion of its solid form, there is adequate evidence that this notion, also, is a mental judgment based on the experience we have acquired in early infancy by the consentaneous exercise of the Visual and Tactile senses. _ Take, again, the case of those wonderful instruments by which our Visual range is extended almost into the infinity of Space, or into the infinity of Minuteness. It is the mental not the bodily eye, that takes cognizance of what the Telescope and the Microscope reveal tous, For we should have no well-grounded confidence in their revelations as to the wnknown, if we had not first acquired experience in distinguishing the true from the false by applying them to known objects; and every interpretation of what we see through their instrumentality is a mental judgment as to the probable form, * Thus, in a recently recorded case in which sight was imparted by operation to a young woman who had been blind from birth, but who had nevertheless learned to work well with her needle, when the pair of scissors she had been accustomed to use was placed before her, though she described their shape, colour, and glistening metallic character, she was utterly unable to recognize them as scissors until she put her finger on them, when she at once named them, laughing at her own stupidity (as she called it) in not having made them out before. Ixxx REPORT—1872. size, and’ movement of bodies removed by either their distance or their mi- nuteness from being cognosced by our Tactile Sense. The case is still stronger in regard to that last addition to our Scientific armamentum, which promises to be not inferior in value either to the Telescope or the Microscope; for it may be truly said of the Spectroscope, that it has not merely extended the range of our Vision, but has almost given us a new sense, by enabling us to recognize distinctive properties in the Chemical Elements which were previously quite unknown. And who shall now say that we know all that is to be known as to any form of Matter; or that the Science of the fourth quarter of this century may not furnish us with as great an enlargement of our knowledge of its Properties, and of our power of recognizing them, as that of its third has done? But, it may be said, is not this view of the Material Universe open to the imputation that it is “evolved out of the depths of our own consciousness”—a projection of our own Intellect into what surrounds us—an ¢deal rather than areal World? If all we know of Matter be an “ Intellectual Conception,” how are we to distinguish this from such as we form in our Dreams ?—for these, as our Laureate no less happily than philosophically expresses it, are “ true while they last.” Here our ‘‘Common Sense” comes to the rescue. We ‘awake, and behold it was a dream.” yery healthy mind is conscious of the difference between its waking and its dreaming experiences; or, if it is now and then puzzled to answer the question “ Did this really happen, or did I dream it?” the perplexity arises from the consciousness that it might have happened. And every healthy mind, finding its own experiences of its waking state not only self-consistent, but consistent with the experiences of others, accepts them as the basis of its beliefs, in preference to even the most vivid recollections of its dreams. The Lunatic Pauper who regards himself as a King, the Asylum in which he is confined as a Palace of regal splendour, and his Keepers as obsequious at- tendants, is so ‘‘ possessed” by the conception framed by his disordered in- tellect, that he does project it out of himself into his surroundings ; his refusal to admit the corrective teaching of Common Sense being the very essence of his malady. And there are not a few persons abroad in the world, who equally resist the teachings of Educated Common Sense, whenever they run counter to their own preconceptions; and who may be regarded as—in so far—affected with what I once heard Mr. Carlyle pithily characterize as a ‘‘ diluted In- sanity.” It has been asserted, over and over again, of late years, by a class of men who claim to be the only true Interpreters of Nature, that we know nothing but Matter and the Laws of Matter, and that Force is a mere fiction of the Imagination. May it not be affirmed, on the other hand, that while our notion of Matter is a Conception of the Intellect, Force is that of which we have the most direct—perhaps even the only direct—cognizance? As I have already shown you, the knowledge of Resistance and of Weight which we gain through our Tactile Sense is derived from our own perception of exertion ; and in Vision, as in Hearing, it is the Force with which the undulations strike the sensitive surface, that affects our consciousness with Sights or Sounds. True it is that in our Visual and Auditory Sensations, we do not, as in our Tactile, directly cognosce the Force which produces them; but the Physicist has no difficulty in making sensible to us indirectly the undulations by which Sound is propagated, and in proving to our Intellect that the Force concerned in the transmission of Light is really enormous*. * See Sir John Herschel’s Familiar Lectures on Scientific Subjects. ADDRESS. lxxxi Tt scems strange that those who make the loudest appeal to Experience as the basis of all knowledge, should thus disregard the most constant, the most fundamental, the most direct of all experiences; as to which the Common Sense of Mankind affords a guiding light much clearer than any that can be seen through the dust of Philosophical discussion. For, as Sir John Herschel most truly remarked, the universal Consciousness of mankind is as much in accord in regard to the existence of a real and intimate connexion between Cause and Effect, as it isin regard to the existence of an External World; and that consciousness arises to every one out of his own sense of personal ex- ertion in the origination of changes by his individual agency. Now while fully accepting the Logical definition of Cause as the “an- tecedent or concurrence of antecedents on which the Effect is invariably and unconditionally consequent,” we can always single out one dynamical antecedent—the Power which does the work—from the ageregate of material conditions under which that Power may be distributed and applied. No doubt the term Cause is very loosely employed in popular phraseology ; often (as Mr. Mill has shown) to designate the occurrence that immediately preceded the effect ;—as when it is said that the spark which falls into a barrel of gunpowder is the cause of its explosion, or that the slipping of a man’s foot off the rung of a ladder is the cause of his fall. But even a very slightly trained Intelligence can distinguish the Power which acts in each case, from the Conditions under which it acts. The Force which produces the explosion is locked up (as it were) in the powder ; and ignition merely liberates it, by bringing about new Chemical combina- tions. The fall of the man from the ladder is due to the Gravity which was equally pulling him down while he rested on it; and the loss of support, either by the slipping of his foot, or by the breaking of the rung, is merely that change in the material conditions which gives the Power a new action. Many of you have doubtless viewed with admiring interest that truly won- derful work of Human Design, the Walter Printing Machine. You first examine it at rest ; presently comes a man who simply pulls a handle towards him ; and the whole inert mechanism becomes instinct with life,—the con- tinuous sheet of four miles of blank paper which rolls off the cylinder at one end, being delivered at the other, without any intermediate human agency, as separate ‘Times ” Newspapers, at the rate of 15,000 an hour. Now what is the Cause of this most marvellous effect? Surely it lies essentially in the Power or Force which the pulling of the handle brought to bear on the machine from some extraneous source of Power,—which we in this instance know to be a Steam-engine on the other side of the wall. This Force it is, which, distributed through the various parts of the Mechanism, really performs the action of which each is the instrument ; they only supply the vehicle for its transmission and application. The man comes again, pushes the handle in the opposite direction, detaches the Machine from the Steam-engine, and the whole comes to a stand; and so it remains, like an inanimate corpse, until _ recalled to activity by the renewal of its Moving Power. But, say the Reasoners who deny that Force is any thing else than a fiction of the imagination, the revolving shaft of the Steam-engine is “ Matter in Motion ;” and when the connexion is established between that shaft and the one that drives the Machine, the Motion is communicated from the former to the latter, and thence distributed to the several parts of the Mechanism. This account of the operation is just what an observer might give, who had looked-on with entire ignorance of every thing but what his eyes could see ; the moment he puts his hand upon any part of the machinery, and tries to 1872. Ixxxli REPORT— 1872. stop its motion, he takes as direct cognizance, through his feeling of the Effort required to resist it, of the force which produces that motion, as he does through his eye of the motion itself. Now since it is universally admitted that our notion of the External World would be not only incomplete, but erroneous, if our Visual perceptions were not supplemented by our Tactile, so, as it seems to me, our interpretation of the Phenomena of the Universe must be very inadequate, if we do not mentally co-ordinate the idea of Force with that of Motion, and recognize it as the “efficient cause” of those phenomena,—the “ material conditions” constituting (to use the old Scholastic term) only “ their formal cause.” And I lay the greater stress on this point, because the Mechanical Phi- losophy of the present day tends more and more to express itself in terms of Motion rather than in terms of Force ;—to become Kinetics instead of Dy- namics. Thus from whatever side we look at this question,—whether the Common Sense of Mankind, the Logical Analysis of the relation between Cause and Effect, or the Study of the working of our own Intellects in the interpreta- tion of Nature,—we seem led to the same conclusion ; that the notion of Force is one of those elementary Forms of Thought with which we can no more dispense, than we can with the notion of Space or of Succession. And I shall now, in the last place, endeavour to show you that it is the substi- tution of the Dynamical for the mere Phenomenal idea, which gives their highest value to our conceptions of that Order of Nature, which is wor- shipped as itself a God by the class of Interpreters whose doctrine I call in question. The most illustrative as well as the most illustrious example of the differ- ence between the mere Generalization of Phenomena and the Dynamical conception that applies to them, is furnished by the contrast between the so-called Laws of Planetary Motion discovered by the persevering ingenuity of Kepler, and the interpretation of that Motion given us by the profound in- sight of Newton. Kepler’s three Laws were nothing more than comprehen- sive statements of certain groups of Phenomena determined by observation. The first, that of the revolution of the Planets in Elliptical orbits, was based on the study of the observed places of Mars alone ; it might or might not be true of the other Planets; for, so far as Kepler knew, there was no reason why the orbits of some of them might not be the excentric circles which he had first supposed that of Mars to be. So Kepler’s second law of the passage of the Radius Vector over equal areas in equal times, so long as it was simply a generalization of facts in the case of that one Planet, carried with it no reason for its applicability to other cases, except that which it might derive from his erroneous conception of a whirling force. And his third law was in like manner simply an expression of a certain Harmonio relation which he had discovered between the times and the distances of the Planets, having no more rational value than any other of his numerous hypotheses. Now the Newtonian ‘‘ Laws” are often spoken of as if they were merely higher generalizations in which Kepler’s are included; to me they seem to possess an altogether different character. For starting with the Conception of two Forces, one of them tending to produce continuous uniform motion in a straight line, the other tending to produce a uniformly accelerated motion towards a fixed point, Newton’s wonderful mastery of Geometrical reasoning enabled him to show that, if these Dynamical assumptions be granted, Kepler’s phenomenal “ Laws,” being necessary consequences of them, must be universally true. And while that demonstration would have been alone ADDRESS. lxxxili sufficient to give him an imperishable renown, it was his still greater glory to divine that the fall of the Moon towards the Earth—that is, the deflection of her path from a tangential line to an ellipse—is a phenomenon of the same order as the fall of a stone to the ground; and thus to show the applicability to the entire Universe, of those simple Dynamical conceptions which consti- tute the basis of the Geometry of the Principia. Thus, then, whilst no “Law” which is simply a generalization of Phenomena can be considered as having any coercive action, we may assign that value to Laws which express the universal conditions of the action of a Force whose existence we learn from the testimony of our own consciousness. The assurance we feel that the Attraction of Gravitation must act under all circumstances according to those simple Laws which arise immediately out of our Dynamical conception of it, is of a very different order from that which we have in regard (for example) to the Laws of Chemical Attraction, which are as yet only generalizations of phenomena. And yet even in that strong assurance, we are required by our examination of the basis on which it rests, to admit a reserve of the possibility of something different ; a reserve which we may well believe that Newton himself must have entertained. A most valuable lesson as to the allowance we ought always to make for the unknown “ possibilities of Nature,” is taught us by an exceptional phe- nomenon so familiar that it does not attract the notice it has a right to claim. Next to the Law of the Universal Attraction of Masses of Matter, there is none that seems to have a wider range than that of the Hwpansion of Bodies by Heat and their Contraction by Cold. Excluding Water and one or two other substances, the fact of such expansion might be said to be invariable ; and, as regards bodies whose Gaseous condition is known, the Law of Ex- pansion can be stated in a form no less simple and definite than the Law of Gravitation. Supposing those exceptions, then, to be unknown, the Law would be universal in its range. But it comes to be discovered that Water, whilst conforming to it in its expansion from 393° upwards to its boiling- point, as also, when it passes into Steam, to the special law of Expansion of Vapours, is exceptional in eapanding also from 393° downwards to its Freez- ing-point; and of this failure in the Universality of the Law, no rationale can be given. Still more strange is it, that by dissolving a little salé in water, we should remove this exceptional peculiarity ; for sea-water continues to con- tract from 393° downwards to its Freezing-point 12° or 14° lower, just as it does with reduction of temperature at higher ranges. Thus from our study of the mode in which we arrive at those conceptions of the Orderly Sequence observable in the Phenomena of Nature which we call “ Laws,” we are led to the conclusion that they are Human conceptions, subject to Human fallibility; and that they may or may not express the Ideas of the Great Author of Nature. To set up these Laws as self-acting, and as either excluding or rendering unnecessary the Power which alone can give them effect, appears to me as arrogant as it is unphilosophical. To speak of any Law as “regulating” or “ governing” phenomena, is only per- missible on the assumption that the Law is the expression of the modus operandi of a Governing Power.—I was once in a great City which for two days was in the hands of a lawless mob. Magisterial authority was sus- pended by timidity and doubt; the force at its command was paralyzed by want of resolute direction. The “‘ Laws” were on the Statute book, but there was no Power to enforce them. And so the Powers of evil did their terrible work; and fire and rapine continued to destroy life and property without check, until new Power came in, when the Reign of Law was restored. lxxxiv REPORT—1872. And thus we are led to the culminating point of Man’s Intellectual Inter- pretation of Nature,—his recognition of the Unity of the Power, of which her Phenomena are the diversified manifestations. Towards this point all Scien- tific inquiry now tends. The Convertibility of the Physical Forces, the Cor- relation of these with the Vital, and the intimacy of that newus between Mental and Bodily activity, which, explain it as we may, cannot be denied, all lead upward towards one and the same conclusion; and the pyramid of which that Philosophical conclusion is the apex, has its foundation in the Primitive Instincts of Humanity. By our own remote Progenitors, as by the untutored Savage of the present day, every change in which Human agency is not apparent was referred to a particular Animating Intelligence. And thus they attributed not only the movements of the Heavenly bodies, but all the phenomena of Nature, each to its own Deity. These Deities were invested with more than Human power ; but they were also supposed capable of Human passions, and subject to Human capriciousness. As the Uniformities of Nature came to be more distinctly recognized, some of these Deities were invested with a domi- nant control, while others were supposed to be their subordinate ministers. A serene Majesty was attributed to the greater Gods who sit above the clouds; whilst their inferiors might “‘ come down to Earth in the likeness of Men.” With the growth of the Scientific Study of Nature, the conception of its Harmony and Unity gained ever-increasing strength. And so among the most enlightened of the Greek and Roman Philosophers, we find a distinct recognition of the idea of the Unity of the Directing Mind from which the Order of Nature proceeds; for they obviously believed that, as our modern Poet has expressed it,— “All are but parts of one stupendous whole, ** Whose body Nature is, and God the Soul.” The Science of Modern times, however, has taken a more special direction. Fixing its attention exclusively on the Order of Nature, it has separated itself wholly from Theology, whose function it is to seek after its Cause. In this, Science is fully justified, alike by the entire independence of its objects, and by the historical fact that it has been continually hampered and impeded in its search for the Truth as it is in Nature, by the restraints which Theologians have attempted to impose upon its inquiries. But when Science, passing beyond its own limits, assumes to take the place of Theology, and sets up its own conception of the Order of Nature as a sufficient account of its Cause, it is Invading a province of Thought to which it has no claim, and not un- reasonably provokes the hostility of those who ought to be its best friends. For whilst the deep-seated instincts of Humanity, and the profoundest re- searches of Philosophy, alike point to Mind as the one and only source of Power, it is the high prerogative of Science to demonstrate the Unity of the Power which is operating through the limitless extent and variety of the Universe, and to trace its Continwity through the vast series of Ages that have been occupied in its Evolution. REPORTS ON PRESTATE OF SCIENCE. > Report on the Gaussian Constants for the year 1829, or a Theory of Terrestrial Magnetism founded on all available observations. By H. Perersen and A. Erman. Tr was in 1838 that the illustrious C. F. Gauss published the principles of a method which made all the phenomena of terrestrial magnetism as fully calculable as are astronomical phenomena by Newton’s theory of gravita- tion. This beautiful accession to natural philosophy may be summed up as follows :— For every point of space, the position of which is given by its distance + from the earth’s centre, and by the angles wu and ) denoting respectively its angular distance from the geographical north pole and its longitude east from Green- wich, there exists a mathematical expression relating to the terrestrial magnetic qualities of this point, and containing only » and trigonometrical functions of w and , together with numerical values that are the same for the whole extent of space. ‘This expression is called the magnetic potential of the point ; and as to’ the said numerical values, we give them here, as we did in the Report on our computation made during the years 1846 to 1848, the name of the Gaussian Constants. This must be understood as relating to their inyariability as to space, but by no means to independence of time. For every point on the earth’s surface, or above it, up to infinite distance, the magnetic potential has a finite value, and in consequence thereof must be calculable as soon as the Gaussian constants are known. ‘There exists no visible or measurable phenomenon which for every given point agrees with the value of the magnetic’ potential; but this remarkable quantity is for every place in explicit connexion with the intensity and the direction of the magnetic force which is exerted there by the causes considered. These two measurable phenomena are therefore given as soon as the potential can be ascertained; and the same is the case with every one of the components which we are wont to form of terrestrial magnetism for the sake of easier observations—as, for instance, with the three rectamgular components, which in their turn are equivalent to the horizontal and vertical intensities and to 1872. B x L 2 REPORT—1872. what we call the angles of declination and inclination. Indeed at any place a component in any direction whatever of the magnetic force is merely pro- portional to the increment which the potential there takes by a small displacement in the same direction. But now the determination of that potential which outside a sphere results from any magnetic actions of its interior, and therefore, according to the last remark, the foretelling of all magnetic phenomena produced by the same causes, become possible and are facilitated by the following circumstances. In every case of the descrip- tion just mentioned the magnetic potential can be expanded into an infinite but converging series, proceeding by integer powers of 2 the exponent of the 5 first one being +1. Among the terms of this series, that which is divided by 7 contains 3 of the Gaussian constants, 2 q 5 ” ” re ‘ ”? ” ." In+1 59 5 In the formula for the potential, each of these constants is multiplied by a theoretically given trigonometrical function of wu and X, and therefore, for any given point, by the numerical equivalent of this function. The algebraic developments which Gauss’s classical work contains for the magnetic potential, as well as for the observable magnetic components, relate also to the actions of a sphere enclosing a finite or infinite number of any magnetic centres whatsoever. Therefore these expressions can represent our terrestrial pheno- mena only after the substitution, for every symbol denoting a Gaussian con- stant, of that number which the individual magnetic qualities of the earth require, according to observations. But then, specially, this transformation of the abstract theory of the magnetic actions of a sphere into the practical theory of terrestrial magnetism will amount to the determination, from a sufficient number of observed values, of 15, 24, 35, or generally n?+2n Gaussian constants, according as it appears that the third, the fourth, the fifth, or generally the nth term in the algebraical expressions of these em- pirical data is the first that is surpassed by the probable amount of their inevitable errors. A first attempt towards the completion of the theory of terrestrial magnetism was made by its illustrious author with material of which the gaps for the greater part of the Antarctic Ocean, and for other vast regions, could only be filled up by graphical guesswork. It led to the conclusion that a restriction to four terms of the potential, and therefore the determination of 24 Gaussian constants, did more than respond to the mean exactitude of the empirical data. To the same effect was the computation that H. Petersen executed from 1846 to 1848, when commissioned for the purpose by the British Association. Indeed, it being exclusively founded on 610. results of careful magnetic measurements made by A. Erman on a. line round the earth between 67° north latitude and 60° south latitude, the resulting new constants re- presented these observed values fully twice as well as did the old ones, and thereby, as must be avowed, up to the amount of their own probable errors. But it having been shown by later experience that, just as was expected, much larger disagreement between reality and both the theoretical deductions, did still exist in those parts of the earth where the one or the ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829. 3 other had wanted empirical supplementing*; and we, in consequence thereof undertaking the recomputation now finished with all available observations, resolved once more to confine ourselves to the determination of the same 24 constants solely. Indeed the material on which we have founded this new and definitive calculation is by its geographical completeness far superior to that of both the former ones; but many of its modern accessions do not exceed, nor even attain the exactitude of the observations mentioned above. According to what we have stated in the beginning, the Gaussian constants must to the same extent be either dependent on or independent of time as are the phenomena of terrestrial magnetism. Now very old and indubitable experience has proved that each of these phenomena undergoes not only the various short-period changes, from which the observer can easily, and is always supposed to free them, but also the so-called secular variations of by far a larger amount. The Gaussian constants being then likewise variable as to time, it appears that they can be determined each time but for one given epoch, and then out of observations which either have been all made at this epoch, or reduced to what they would haye given if made at the same. The aim of our present calculations was to determine with all attainable exactitude the Gaussian constants for the year 1829, in order that the results of the newly founded theory might be directly comparable as well with those of their first evaluation, relating nearly to the same epoch, as with the most careful measurements made by Hansteen and Erman between 1828 and 1830. But, as for carrying this out we had to make an equal use of all ob- servations to be relied upon, and originating whether in the selected epoch or at any interval whatsoever before or after this time, our work was divided into two independent parts :— 1. Formule were to be constructed and employed for reducing each of the magnetic results which, at widely differmg times, had been ob- tained by observations all over the earth’s surface, to what they would have been in 1829; and 2. Out of these reduced values, twenty-four numbers were to be com- _ puted which, when taken for our twenty-four Gaussian constants, responded as nearly as possible to all empirical data observed in, or reduced to, the epoch 1829. I. Reduction of Observed Values to the Year 1829. Without the existence of the Gaussian theory, the only means to execute such reductions would have been, for every kind of magnetic phenomena at any place, to guess what changes they had undergone, according to the changes which had been observed for the same phenomena at certain other places. Such rude attempts have indeed been made for the purpose of ascertaining the changes of declination at places where they had never been observed. They could perhaps have been extended, though with much less foundation on experience, to inclination-changes ; whereas for the secular variations of intensity not even this appearance of a means existed, owing to an almost total want of data. But the problem of our reductions has now * As, for instance, according to the comparison made by A. Erman, between the results of both systems of constants and the magnetic observations at some places in India, by Mr. K. Koppe, who was commissioned to do so in the Total-Helipse Expedition of 1868, as published in the ‘ Astronomische Nachrichten,’ vol. lxxy, p. 242 e¢ seg. P Ba A, REPORT—1872. been stated in proper form and has been greatly simplified, since theory has shown that, and how, all kinds of magnetic secular changes, for any arbitrary time and place, depend on one common cause, viz. on the synchronous changes of the Gaussian constants. Indeed these quantities only can give to the alge- braic expressions of magnetic elements different numerical values at various epochs, because the quantities r, u, and \ are by their nature once and for ever invariable ; and then, as only the first power of every Gaussian constant, ‘and no products of them, occurs in the potential, the following general rule can evidently be laid down :—The amount of change for any element of terrestrial magnetism (as, for instance, for the declination, the inclination, one of the three rectangular components, and so forth) during a given period must be calculated by that same formula which expresses its absolute value, if only instead of each Gaussian constant there is placed the increment which its value has received during the same period. This plain corollary of the magnetic theory has been of twofold use for the reductions we had to make, and will serve in the same way for all future ones. Indeed its inverse application gives, from observed changes of magnetic phenomena, the synchronous changes of the Gaussian constants; and by substituting these latter results in the direct formule, the changes of every phenomenon may be computed for places where they have never been observed. ‘The first part of this pro- ceeding is immenscly preferable to empirical guessings; for it makes an almost equal use of the variations in any kind of magnetic phenomena, and thereby leads to the knowledge of these variations in those kinds for which experience is wanting. The secular changes of intensity may therefore be ascertained for periods in which we know only changes of inclination and declination, or even for those in which the latter only have been observed. Moreover it is only by these means that the consequences of experience on secular changes in certain parts of the earth can very confidently be extended to the re- motest parts. Nevertheless, before we could make the application of this memorable method, a decision was wanted concerning two points, according to the result of which our proposed reductions might prove to be either easy or difficult, or even wholly impracticable; to wit :— 1. What kind of connexion exists between the lapse of time and the variations which are undergone by magnetic phenomena and consequently by the Gaussian constants ? and 2, In how many and in which of the Gaussian constants will the varia- tions be of most influence, and in which others may they be neglected for practical approximation ? As to the first question, it has been proved by the changes of the three magnetic components at Berlin, observed fully during the last forty-five years by Erman, and partially at intervals during almost a hundred years by others, and besides by a great number of partial series of observations at other places, that during the last century the variations of magnetic phenomena, and consequently those of the Gaussian constants, have never happened by a leap, but have always progressed according to the law of continuity, and especially so that their amount has been merely proportional to the lapse of time and to its square. If, therefore, the increment of one of these constants from a year denoted by T’ to another denoted by T has been . at . : 5 ascertained, the ( eh of this quantity will be equal to the annual a Wy increase of the same constant for the year denoted by ae More- ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829, 5 over it follows that, by the knowledge of such annual increase at two moments separated from one another by a sufficiently long space of time, we can calculate not only its value for any moment, but also that of the corresponding total increase during any period. Therefore the materials we possessed (as is to be shown hereafter) for computing the annual increments of the constants for the year 1811 and for the year 1843-5, must suffice for our reductions; but before employing them we had to consider the second of the above-mentioned questions. An indubitable answer to it was, of course, that we had to take into account and to determine the variation with time for all those twenty-four constants the values of which were to be deter- mined afterwards by the reduced observations. The solution of the problem up to this highest degree of exactitude will at some future time be a beautiful result of our present work, combined with a similar one for a later date ; but had we undertaken it now, the preparatory task would not only have become more extensive than the essential one, but would even have been impeded by a most sensible want of means. We had therefore to content ourselves with making our reductions for secular changes an approximation to reality, in the same way as astronomers do when, in computing secular planetary perturbations, they disregard the terms of less influence. So in this particular case it was resolved to take into consideration only the changes of the first two terms of the potential—that is to say, to ascertain for two epochs the annual increments of the first eight of the Gaussian constants. A. On the Equations for annual Increments of Constants during the year 1811. In order to ascertain the amount of the annual changes of the Gaussian constants marked by oa Gun ey, os gs igen ae and pz? for our first epoch of 1811, we have founded the computation on :— 1. The increments of declination which appear as having happened from the year 1784 to the year 1840, from a comparison of the maps of isogonic lines constructed for the said years by C. Hansteen and Ki. Sabine; and 2. The increments which inclination has undergone from 1780 to 1840 and which appear as differences between the isoclinal maps of the same authors, The increments of these two phenomena were taken by comparing the said maps for forty-two points of intersection between the meridians of A=0°, 60°, 120°, 180°, 240°, and 300° and the parallels of u=80°, 50°, 70°, 90°, 110°, 130" and 150°: and then, if « and « respectively designate the fifty-six years’ increment of declination and the sixty years’ increment of inclination, and iy Oy Oy yy O5, Oy A, and a, respectively the sought-for annual increments of the Gaussian constants 10 Il zit 20 21 79 a9 22 GsF 2 SF GF yh”, Gg, and h??, 6 REPORT—1872. there were formed forty-two conditional or primary equations to schedule (1), and then just as many to schedule (2). ( With w for the horizontal intensity, d for the declination, and «= 56 there had to be calculated for the « measured w.sin 1° by degrees of arc :— a=—sinu.sind, b=+cosw.cosr.sind-+sin). cosd, c=-+cosu.sind.sind—cos).cosd, d=—sin 2u. sind, (1) woes. < e=-+cos 2u.cosX.sind+cosu. sind. cosd, f=+c0s 2u. sind. sind—cosw.cosdr. cosd, g=-+sin 2u.cos2\.sind+2.sinw.sin 2d. cosd, h=-+sin 2u.sin 2\.sind—2.sinw. cos 2d. cosd, and then formed as primary equations, to which the sought- for a,....a, had to answer as nearly as possible, : a 5 =0.d,+b.a,+¢.a,+d.a,te.a,+f.a,+9.a,th.a,. ( The. orsixty years’ inclination-increments being measured ie ea 0 by degrees of arc, with 7 for the inclination, x, = ——_—., there (4 § ee Th had to be evaluated :— a=—sinw.sin?.cosi.cosd+2 cos wu. cos’ i, b=(cosu.cosd.cosh\—sin.d. sind). sin?. cosz +2.sinw.cosd. cos 2, c=(cosu.cosd.sind+sind. cos) sin7. cos? +2.sinw.sind. cos*i, | d=—sin .2u.cosd.sin?. cosi+(3. cos’ u—1) , cos”, Sey e=(Cos 2u . cosd. cosd—cos wu. sind. sind) sin?, cost (2) . +2.sin 2u.cos). cos*2, +32.sin 2u. sind. cos*%, g=(sin2u . cos2\. cosd—2sinw.sin2d.sind).siné. cos? +3 .sin?u.cos 2d . cos*?, h=(sin 2u .sin2\ .cosd+2sinu.cos2\.sind).sin?. cost +3.sin?w.sin 2). cos*2, | f=(cos 2u.sind.cosd+cosu.cosrX. sind). sin?, cos? and then to be formed as primary equations, to which the a,....@, had to answer as nearly as possible, n= ~ $0.0, +b.a,+0.0,+0.0,+6.0,+f.0,+9-0,+h.a,. 1 The forty-two numerical values of o and « which we have used in the primary equations to the preceding schedules (1) and (2) are shown in the ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829, 7 following Tables. They form the first horizontal line for every value of w, and are marked Ma. when directly made out by the aforesaid maps. We subjoin to them, in the second line for every w, and marked by Ca., the corresponding calculated values, which, according to the solution of our final equations, as has to be shown hereafter, are at once conformable to theory and the closest to the results obtained from the maps. Values of o or increments of Declination from 1784 to 1840. A= ary 60°. 120°, 180°. 240°, 300°. ¥ a °o ° ° ° ° ° °1 Oe +23 —5'4 —13 + 2'2 — 87 + 7'5 BOT Oars.) arr —8°83 —2'37 + roo | + 135 | +1495 50° vor” +o'2 —39 +17 + ro — 27 + 4°5 a eiives —o'o2 —4'70 —0O'75 + 027 + o'60 + 9°40 40° Mav....6 +13 —3°8 +0°5 + ro — 32 + 22 Ca. ...006| —0O°74 =4°31- +1°04 + 217 + O19 + 2°95 90° {02 acveees +4'4 —4'5 —o'9 + 12 — 3°0 + 09 Caras. +3749 —2°'08 +0°38 — 1°56 — 1°92 + 3°01 110° 6 Aone +63 —o'74 +o'2 + 08 — 40 + 43'1 (OS Ree +5714 +1'08 +o'51 — 2°52 — 2°41 + 3°21 30° { at Bon sop +94 _ 24 —4°3 — 07 — 71 + 3°5 - Gao zs, . +349 |. +1°82 +2'26 — 2°02 — 280 | + 1°22 Be |, Shai « +8°6 +69 —5'0 — 39 —133 + 21 Bt Cas css. +613 +6:00 +437 —ro'04 | — 4°24 | + 2°93 Values of « or increments of Inclination from 1780 to 1840. A= 0° 60° 120°, 180°, 240°. 300°. % ° °o ° ° ° ° er WHEN AA See — 2:0 +o'9 +3°5 +14 +2°1 —o'6 3 Ca. ......] — 2°49 —0'03 +2°15 +138 +171 —1'74 50° {oe beonces — 28 +08 +2'0 +2'4 +3°3 +1°6 Ca. ..- — 5°37 +0'41 +2°36 +138 +4°04 +0°89 70° fia —10°8 +2'7 +19 +4°6 +8°6 +0°6 | OE ae — 2°37 —1°00 +2°27 + 1°00 +4'18 +3'04 90° {o2 ‘peer —136 +o'2 foe) +41 +7°5 +30 Ca... — 418 —4'85 +1°37 —o'ls +6743 +3°61 vise Massie. —13°0 —2'8 —37 —o's +2°5 +372 Ca. sevsee] — 1°37 —3°76 —2'43 —0'24. +7°81 +9'73 o { Ma — 4°6 9°0 =a —o'9 +4°9 +69 130 \te Beene — 6°28 —3°86 —4°31 +296 +o'80 +1°51 150° los paeewius +12°0 +0°5 —1'5 —4'0 +6:'0 +71 Ca | + 2°0 —0°39 —1'98 —o'4o +3°'07 +441 8 REPORT—1872. The coefficients a, b....% of the primary equations have been calculated with d and 7 as nearly given for 1811 by a mean between the indications of both isogonic and of both isoclinal maps, and with w as sufficiently known since 1829. B. On the Equations for annual Increments of Constants during the year 1843°5, We have already mentioned that our second determination of a set of annual increments a,,@,....a, of the first eight Gaussian constants was intended to give these quantities for the date 1843°5. This date follows indeed from being the middle of the period 1829-58, during which had happened those changes of phenomena on which we first founded our conditional or primary equations. These were the values of o or increments of declination that we obtained by a comparison between the normal or theoretically interpolated declinations for 1829, as given in the ‘ Magnetische Atlas’ by Gauss and Weber, and the corresponding ones for 1858, as re- presented by the isogonic lines in Berghaus’s Chart of the World. These increments result as follows for thirty-six of the before-mentioned points :— Values of o or increments of Declination from 1829-58, N= °°, 60°, 120°. 180°, 240°, 300°. Ue ° ° ° ° ° ° Owe idusenees —2'2 —4'1 +3°5 —1'6 —=A'3 +1'7 RO Cwereantas ven 57, +0'5 +1°5 —1°8 +0°3 +5°0 HOD sseseeened —s‘i +13 +o'2 —03 +2'1 +0°6 QO “seseseree| > =f-O°E —o'l +02 +2'0 © +24 —o'2 HILO Visvetserd +4'4 —3°7 +13 —0'7 —o'r —o'2 GO se tennst prs | +3'°9 —1'5 o'o —2°7 +2°8 —0'4 As no sufficient data exist for a similar collection of the changes which inclination has undergone during the same period, we have completed our material by the following results of researches on secular variation of magnetic elements. If é generally denotes the annual increment of any element for the date 1843-5, and f the total magnetic intensity, there were put X=f.cosi.cosd, Y=f.cosi.sind, Z=f.sini, as well as p for the so-called weight or measure of probability ; and then the following numbers were ascertained, in order to be afterwards combined into conditional equa- tions with the sought-for @,, @,....@,, or annual increments of constants. ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829, 9 Annual Increments of Magnetic Elements for the date 1843-5—the variations of X, Y, and Z being measured by units of intensity, the variations of d and of i by minutes of are. Number The results of u. d. OX. oY. Nee 70 ee meen ARE Sale station. 5 & o i fo] t \, ms 37 28°08 | 13 23:20} +0°570 | —0'672 | —2°710/ 4 At Berlin. 2 48 45 352 30°0 +2'996 | —0'469 | +1'087|3| Out of Erman’s ob- servationsin Spain and France for 1853°7, and on the Atlantic for 1880. +0'039 | —1'277|3|AtCapeTown. En- glish observatory. 4. 46 20°74. | 280 38°5 —o'265 | —0'243 | +0'165|3)|At Toronto. Ibid. 5. 76 56 80 17 +0°856 | —o'310 | +0°856|3|At Madras. Ibid. Gr | 132 5255 (| 547 27°75 —orogo | —o'261 | —o'014| 3|AtHobarton. Ibid. We 24 46°47 | 64 39°50 | —o'116 | —o'681 | +1°436) 3 At Obdorsk and Be- resowsk. Observa- tions for 1828 and for 1849. 8. | 133 21'4 | 225 307 +1'002 | —3'r49 | —6°604/|1| Onthe Pacific. Out of observations in 1830 by Erman, and in 1843 on , English ships. 9. |132 68 | 308 18'9 +8:069 | +0°693 | —5°796| 1 | Ibidem. IO, |14I 32°71 | 254 31°0 +3'105 | —6630 | —5'994| 1 | Ibidem. Ir |143 55°0 | 302 10°7 4+7:415 | —0'065 | —5°763|1 | Ibidem. 12, |147 16 283 56°3 +4'140 moe — 6°649| 1 | Ibidem, od i 13. |105 55°43 | 354 16'or \(+2'347) |(—4"118) |. oe 2|AtSt. Helena. En- glish observatory. Intensity-changes not observed. a ee ee ee The quantity p being supposed to express the number of direct obser- vations which might have given a result of equal accuracy to that in question, it ought to be inversely proportional to the square of the probable error of this result, which latter, in its turn, is unknown. Therefore our suppositions on these values of p could pretend to no more than an approxi- mation to reality, and were then founded partly on regard to the exactitude and completeness of the absolute measurements at different places, partly as follows from some regard to the dates of these performances. Out of the preceding values of annual increments, only those under 1 and 3 have been derived immediately and exclusively from observations at the places named in the same lines; and then, especially if the date is generally marked by 1800+¢, the numerical absolute values of magnetic elements are expressed for Berlin, or with wu and ) as under 1, according to Erman’s ob- servations, by d=18 7-55—0-0700362 . ((—1-914)?, §=66 37-20 +0:02125 . (t—102-2)%, w=50204-+0-0068043 . (¢—16-108)*; 10 REPORT—1872. and for Cape Town, or the position as under 3, according to what we have derived from all local English observatory journals, by d= 29 33:85—0-11273 (t—58-04),, i= —58 51-07 +0-02242 (t—165-58)', w=588-95 + 0-02813 (t—61-806)*. Now by developing out of each of these expressions, with t=43°5, their absolute values as well as the annual increments éd, ¢2, and éw of the same, and then introducing these quantities into the easily proved expressions, oX=cosd. dw—w.sinl’. sind. éd, oY=sind.dw+w.sinl’.cosd. dd, oZ=tan?.dw+w.sinl’.sec?7. di, these increments of rectangular components for 1843-5 are obtained as above under 1 and 3. But for all the other above-named places, the existing observations, when treated as the last mentioned, did not give complete expressions for d, 7, and w, but only their expressions for limited periods. The annual increments of the components X, Y, Z, which were determined from such observations, in general did not exactly pertain to 1843°5, but to a value of ¢ somewhat different from 43:5. Now, as our computation for the first epoch, or 1811, had already furnished the increments of the constants a,, «,...,a, for the same, we have, first, calculated (by the help of the following formule (3), (4), and (5)) the annual increments of X, Y, Z at the same places for 1811, and then, having denoted the value of any one of these increments for 18435 by 8, 1811 by 3,, 1800+ by a, we have determined the results, as given above under number 2 and numbers 4 to 13, by the relation s==3, 4 —— _ (43°51), There were, in particular, to be used for the increments under numbers 2, t=41-4, 4, t=35, 5 and 6, t=48-5, 1, #=08'5, 12, t=36, 13, t=45; whereby it appears that the empirical elements of our equations were in- fluenced, to an always slight but not wholly equal extent, by a former calcula- ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829, 11 tion. The values attributed to p had therefore to be assumed with at least an additional regard to this circumstance. Now, as for the conditional equations themselves, between @,, a, 1843-5, and the empiric data hitherto recorded for the same year or for the period 1829-58, it appears, first, that these equations for the “o or increments of declination from 1829-58” had once more to be formed according to schedule (1) (of A, or “equations for 1811”). In this schedule we had again to make n= 7%, but this time with c= paca 5 w.sin 1° As for the two values éd and oi that are recorded under number 13, we have employed for dd the said schedule (1), and in it have taken n= ed vith K ee tt ey. sin L” after substitution of tet with a Oe and then, finally, all the : K w.sin 1 and for di the schedule (2) (of A, or “ equations for 1811”), recorded values of dX, 5Y, and 8Z were set in equations, according to the following schedules (3), (4), and (5), which we had derived for the purpose. ¢ With a=-+sin u, d=-+sin 2u, g=—sin 2u . cos 2d, b=—cosu.cosr, e=—cos2u.cosd, h=—sin2w.sin 2A, ES coy usin A, jf=—cos2u.sind, there is n=dX=a.a,+b.a,tc.a,td.a,te.atf.a,tg-%, th. 5 with a=0, d=0, g=+2sinu.sin2), b=+sinX, e=+cosu.sind, kh=—2sinw.cos2d, (4) c=—cos\, f=—cosw.cosr, is | n=cY=a. a, +b.a,+6 dtd. ate.a +f. atg- a, +h. 5 and then with a=+2 cos u, d=+(3.cos*u—1), g=+38sin* w.cos 2), b= +2sinu.cosdA, e=+3.sin2u.cosr, h=+3.sin’?u.sin2aA, (5) .-< c=4+2sinusindA, f=+3.sin2u.sind, there is again n=dZ=a.a,+b.a,4+¢. a,td.ate.a,+f.atg. a, +h . a. C. Bvaluation of the annual Increments a,, &,.. .+% of the Gaussian constants og hs e.g yh, g, and 7? for both epochs, and Re- ductions made, by the help of these increments, of magnetic Observations from different dates to 1829. The heretofore described means had now supplied us for 1811 with eighty- 12 : REPORT—1872. four, and for 1843-5 with seventy-four numerically different equations of the form n=a.¢,+b.a,+¢.a,+d.a,te.a4f.a,ty.a,th.a,, which directly to satisfy was of course in both cases impossible. But in order to determine those two sets of the eight unknown «,, a, .a,, Which according to the rules of probability had to be assumed for the first and for the second of the said years, it was necessary to supply the just mentioned theoretical form of the conditional equations by the practically possible assumption of v=(—n+a.a,+b.a,+¢.a,+d.a,+¢.a,4f.a,t9.a,th.a@,). Vp, p and v in this expression being meant to stand for the so-called weight of every value of n, and for the error to be supposed in it. Tf, then, [ ] indicate generally a sum of algebraically similar terms, and if the assumed values of the error v be regarded as functions of the un- known, we shall obtain the most probable ‘values of Ds Oe en tae a, by the solution of the following eight final equations under (6), which in their turn are but evident consequences of the general principle under (©) (GC) SSeS ore [v?]=minimum. [ogo |] =o Leet Leap, + Lab e + leer les + ede +[aep]a,+(afp}a,+ (agp ]a,+ lahp jay. [v.92 ]=o= —Dnp]+ [apes + [bop le. + ee, + bape, 2 +[bep jas +[ Sfp ja, +[ 9p la, + [bhp Ja. E 5 |= =o=—|[enp]|+[ cap ]a,+[ebp ja,+[ cep ja, +[edp Ja, \ +[eep]a, +0 ofp ke, +Legp la, +[ chp ja,. E : =| =o=—[dnp]+[dap ja, +[dbp ja, + [dep ja, +[ddp Ja, +[dep ja,+[dfp \a,+[dgp \a,+[dhp Ja,. [» ; i | =o=—|[enp]+[ cap ]a,+[ ebpja,+[ecp la,+[edp ja, +Leepla,+[ fpla.+Legpla,+ehp]a,. [»: ot | =0=— Lin] + Lire, + Lope. fp ke, + hee, : +L fep s+ ff le, + for Ja, +1 she lay. [» =| =o=—[gnp]+[gap]a,+[9>p]a.+[oep Ja, +[9¢p Jay ; +[gep ]as+lofp le.+[o9p la, +[ohp ja,. [ys : uD A =o= —[hnp]+[hap]a,+[Abp ja, + [hep ja,+[hdp]a, L + [hep ]a,+[hfp la, +[hgp Ja, +[hhp ]a,. We have here retained the general form of this prescription for calculating a,,@,....a,, though when employed for the year 1811 it became simplified ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829, 13 by the occurrence of p=1 in every one of the eighty-four termed sums [ ]; whereas in the computations for 1843-5 we had to substitute in the sums [ ], now unity, now another number for the p’s of the seventy-four terms, according to the empirical values for that year, as above mentioned under “B, On the Equations... . for 1843°5.” Now the numerical values for the final equations (6) have been found to be :— For the year 1811. [aa]=+3:970, [ab]=—4990, [ac]=+10°685, [ad]= + 0-235, [aeJ=+3:200, [af]=+0°109, [ag|=—0°353, [ah]=+4-971, [an |=—8-541, [6b] =+68-229, [bc]=+3-758, [bd]=+2-881, [be]=—0-408, [ofJ=+1-906, [bg]= —3-264, [bh] = +5-044, [bn]=—15-069, [ec]=+62:186, [ed]=—2°742, [ce]=+2:290, [cf]=+1-954, [eg|J=—6°771, [ch] =—11:994, [en] =—32-370, [dd]=+23:994, [de]=—0-455, [df]=—2-493, [dy]=—3-006, [dh |=—3:110, [dn]=—8-427. [ce]=+16-280, [ef]=+0°699, [ey]=—O-414, [ch]=+7-918, [en]=—15-486, [ff ]=+13-402, [fy]=—6-608, [fh] =—1-268, [fr]=+13-745. [gg ]=+138-801, [gh]= +5350, [gnJ=—44-715. [Ah] = + 134-680, [hn]=— 6-073, For the year 1843°5. [aap |= +67°883, [abp|=+12:989, [acp]=+9:091, [adp]=+8-784, [aep |= + 20-978, [afp]=+2°959, [agp |=+0°407, [ahp |= +8-036, Lanp |= + 64-265. [bbp]=+75:°782, [bep]=+2:961, [bdp]=—3-325, [bep]=-+0-198, [dfp |= —1-578, [bgp |= + 31°818, [bhp ]= +5-062, [dnp |= — 23-362. fecp]=+71:859, [edp|=—3:574, [cep]=+3°691, [efp]=+3-067, [egp |= —3°337, [chp |= +23:278, [enp]= + 25-870. . [ddp |= +42:260, [dep] =+7:160, [dfp|=+8:076, [dgp]=+2-040, [dhp|=—1-:781, [dnp |= — 29-599. [eep = +43:335, [efp]=—0°359, [egp]=+10-268, [chp]=+6-543, [enp |= — (862. (Afp |= +87-446, [ typ |= —5'698, [ fhp]= +8°145, [fnp]= —12-456. [gop |= +154:637, [ghp|= — 5424, [ynp]=—59-602, [Ahp]=+122:981, [knp]= —18'439, 14. : . REPoRI—1872. The solution of the equations (6), when these groups of numbers were successively substituted, gave then the two sought-for sets of results as follows :— f { > Column of 6,,.,, or | es sec cher Es ag oe values of saul called pertains ‘to annual increments increments Theweonstaeies | fori, for 1843-5. tee re urs oe —0-916 +1-339 oo Cees gi — 0-303 —0-465 eras Seite 25 hs? —0-388 +0:280 ee Ln eer gre —0°301 — 0-829 GAs oat ss ge 0-705 —0°621 Bete tts +2 al +0-966 —0-290 ie eines Fk ge —0-314 —0°255 aot ees Ce +0:027 —0-242- Now, with the help of this Table, the rule for the reduction of any magnetic element that had been observed in the year 1829 +7 (with 7 for any positive or negative number) to what it must be stated to have been in 1829, proved to be :— 1. That to the observed value must be added the number which hereto- fore has been uniformly designated by ; 2. That this » has to be calculated by the schedule (1) (under “A, On the equations” &c.) when a d or a declination is to be reduced ; by the schedule (2) (under the same) when an 7 or an inclination is to be reduced ; by the schedule (3) (under “B, On the equations” &c.) zontal component is to be reduced ; when Y or the western hori- zoutal component is to be reduced ; by the schedule (4) (under the same) by the schedule (5) (under the same). when X or the northern hori- when Z or the vertical com- ponent is to be reduced ; and 3. That, independently of the nature of the observed element, when calculating its reduction n, there must be substituted, in the formula employed, for a, (with , for the integers successively from 1 to 8), a 6, which corresponds to the following expression, when ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829, 15 assuming the numbers marked ¢,, and 0,,.,, under the same super- scription out of the »th horizontal line of the Table :— 8 =-. —_ - 6,,—36 . Bs) +rr z (Gee “ M-++rr F N*. ‘ 65 tens wee To facilitate this evaluation, we used the form gv=r. M-++7,.N, and the following logarithms according to the superscriptions under which they stand : As a further illustration of these rules, we give the following example of In 1818-5 or for r=—10°5 were observed ».¢ Y 7, 73-96, 171-92, our reductions, When 3, is it must be formed | It must be formed Metictititod fox with log M, with log N, as follows as follows olen Rae a 95237 n 85403 n ye generte eopae 9-5942 7-3963 (RT rte te 8:2504 8:0121 » a is 977385 79094 Wee eters S: 9-8442 T4279 n Cie glpplinedt atete 9:4315 8-2864 OTE Sees 94488 6°9509 n a Sigg eee 9-0871 COMA: U 21° 38’, r 306° 10’, hence for 6. =M .r+N .77 is obtained log 6,, when standing for loga,, 95036 n; loge, 058542; loga,, 0:1865n; log «,, 0-7271 1; log a,,0:9794n; loga,, 0°6963; loga,, 0-4843n; log a, 747A n. log a, 9:5667 ; log b, 9°7393 n ; log e, 9'6332 n; in dX, according to schedule (3). And for dX, aa,=—0-12, ba,=+4+2:12, ca,=—1-03, da, = —365, ca,= +410, fa,= +2:92, ga,== —0°63, RO therefore log f, 9°7694 ; log log 1609°74 ; c, 9:8753 ; g, 9°3180 ; log d, 98359 ; log h, 9°8149, éX=[aa,+ba,. cari +thaJ= 4+3°35; X+édX=77-31=the reduced X. * Tt scarcely needs to be observed that the above rule applies verbally to reductions from a year 1800+7, to a year 1800+¢ (¢, and ¢ standing for any positive or negative numbers whatsoever), if only into 6,=7.M-+z7r.N are introduced Be gs (20) Oa nag we to Saas r=t,-t, M= 65 65 16 REPORT—1872. log a,—«; log b, 9:9070 n; loge, 97710 n; logd, —w; loge, 9:8753 n; log f, 97393 n; log g, 9°8467n; log h, 9°3498, in 6Y, according to schedule (4). And for bY, aaz,=0-00, ba,=+3-13, ca,=+0-81, da,=0-00, ea, =+7:16, fa,=—2:72, ga,=+2:14, ha,=—0:13; therefore dY=[aa,+ba,+....+h.a,]=+4+1039; Y+6Y=182:31=the re- duced Y, log a, 0°2693 ; log 6, 9°6387 ; log ¢, 0°7747 n; log d, 0:1932 ; log ¢, 9°7830; log f,9°9190n; logy, 8-9926n; logh, 95895 n, in ¢Z, according to schedule (5). And for 64, da,=— 0°59, ba,=—1°62, cas=+8'15, da,s=—8-32, ea,=—5-79, fa;s=—412, ga,=+0°30, ha,=+0°22; therefore dZ=[aa,+ba,+....+ha,J=—11°83 ; Z+8Z=1597-91=the reduced Z. II. Computation of the twenty-four Gaussian Constants from values observed in or reduced to 1829. The numerous applications which we made of these means of reduction, not only have added considerably to the number of empirical data for our intended research, but they have also increased the intrinsic value of the whole stock of such data. Indeed many observed elements which by their reduction to the epoch 1829 became applicable to our purpose, related to points of extensive regions where all knowledge of magnetic phenomena had been hitherto wanting. Such were, for instance, the beautiful series of magnetic measurements which English navigators haye executed in the antarctic and North-American glacial oceans, and also many magnetic determinations in the interior of the United States. Therefore the materials now collected must amply suffice for our purpose ; but it seemed at first sight as if for its attainment two entirely different ways were left to our option. Further consideration, however, has convinced us that of these ways or modes of operating only the one which we have adopted was admissible ; but this consideration, together with the doubt which it settled, merits to be shortly explained here. According to a first plan of operation, we had to begin by calculating for every newly added magnetic element its excess n over the theoretic value assigned to it by the old approximations for the Gaussian constants—then, having formed for each of these results (with a,, a,....a,, for given functions of w and A, and Ag”, Ah””, every v and p respectively varying from 1 to 4 and from 0 to 4, for the corrections of constants) the expression n=a,Ag'+a,Ag''+a,Ah + .... +a, Ants, to derive from each of these primary equations its corresponding contributions to the twenty-four final equations for Ag", Ag™!,..,Ah**; and lastly, ? ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829. 17 having added each of these contributions to the similar one among those equations which H. Petersen has stated to represent all the magnetic elements measured by Erman in 1829*, we had to solve the so completed expressions according to the sought-for corrections, Ag’®, Ag™!, Ak'?....Ah**. On the other hand, instead of such indifferent aggregation of all new material to all the old, we bad, according to the second method, to make a proper abstract of each of the two classes of data, and then to derive the sought-for values of constants from equations founded only on these abridged materials. _ But as the most probable determination of the Gaussian constants is evidently only obtained by observations at points symmetrically situated all over the earth’s surface and being all of equal weight (that is to say, reliable to an equal extent), the beforementioned method proved to be doubly imperfect. Indeed the material for the said former calculation of H. Petersen consisted in 610 magnetic elements, which corresponded to 650 direct observations executed along a line round the earth of 8100 German miles. The three data for the magnetic determination of a point, therefore, were to be found all over this line at an average distance of 37-4 German miles, or of very nearly 2°5 of the equator, whereas when those points for which magnetic elements had now to be added were counted in their succession on parallels of latitude or on any other lines round the earth, there appeared everywhere a much scantier distribution, which on an average did not exceed a sixth or a seventh of what it was for the former calculation. On immediate addition of the former sums of final equations to the corresponding new sums, the resulting new values of Gaussian constants would therefore have been influenced to an exceedingly larger extent by the magnetic character of one almost linear tract of the earth’s surface, than by all its remaining parts. To compensate such vicious preponderance, we might, before adding the two sums, have multiplied each of them by a number inversely proportional to the frequency of its elements. But this proceeding supposed, in order to be right, that all constituent observations were of equal weight, while in our case we must own, on the contrary, that the probable errors of the newly added elements surpassed those of the formerly observed ones in a considerable though rather indefinite proportion. Indeed by separate comparisons of some of the new and of the old observations with others of their respective classes, the new seemed upon the whole in less accordance, partly of course in direct con- sequence of the manner in which they were made, partly because of their having been reduced to 1829 by a method which, for all our care, was but an approximation to reality. We have avoided these difficulties by choosing the second of the above- mentioned modes of operation and by prosecuting it as follows :— Out of all stations for which the three rectangular magnetic components, as in 1829, had become known, either by direct observation or by our reductions for secular changes, we selected those which are nearest to ten parallels of latitude between w=23° and u=165°, and at the same time to the one or the other of nine equidistant points of every one of these circles. Having then concluded out of the results for these stations the 270 elements that belong to the 90 predetermined points, these latter values were ex- clusively introduced into the like number of our primary equations, which in * As published in the Report of the Highteenth Meeting of the British Association, held in 1848, tables facing p. 98, under “ Final Equations for the corrections of the Gaussian constants from 610 magnetic elements.” 1872. c 18 REPORT—1872. their turn gave the final equations for the most probable twenty-four values of Gaussian constants. It appears that by so doing we have given to the data of observation, jist, the requisite symmetrical repartition over the earth, and then, secondly, to all its parts the nearest possible equality of weight. Indeed, when selected as just said, there followed one another quite casually, on each parallel, observations that were instituted in 1829 and those which had been reduced to this year, now from the earlier date of their direct validity, now from the later one. These data became therefore affected by the still remaining defects of reduction to a different extent and in alternate directions, just as by those inevitable errors of observation which the usual formation of final equations supposes to exist in their numerical material. But then, lastly, as to the reduction of elements from the spots of direct observation to the neighbouring predetermined points, we have avoided its pre- judicial influence by always using a merely mechanical interpolation, relating to points which in latitude as well as in longitude differed in alternate directions from those points to which we were to reduce them. The following Table contains, according to the hitherto used notation of X=f cosicosd, Y=f cosi sind, and Z=f sinz, those values of 270 magnetic elements for 1829 on which our new values of the Gaussian constants have exclusively been founded. To these fundamental numbers are added under AX, AY, and AZ, their respective excesses on the values which a. computa- tion with the old assumed constants assigned tothem. These latter numbers show thus to what extent the hitherto existing theory of terrestrial magnetism still wanted correction in different parts of the earth’s surface. It is still worth mentioning that, for the determination of our following normal values of X, Y, and Z, we have employed out of the vicinity of the parallels to u= 23°, 39 observed elements, » “= 30°, 63 ” ” » US 40°, 63 ” ” » v= 50°, 42 ” ” » US ihe 27 ” ” » v= 90°, 39 ” ” » U>= 105°, 30 ” ” or altogether 303 direct measurements for 7 values. As for the remaining three parallels, to ~=130°, w=150°, and w=165°, we have directly (though always after reduction to 1829) assumed the 81 elements which General E. Sabine, in his ‘Report on Magnetic Observations in the Antaretic Ocean,’ assigns to the intersections of these circles with the meridians to \=40°v, where » denotes the integers from 0 to 8. He has of course deduced these values from a larger number of observations at neigh- bouring points; and by assuming this number to be 97 or from 32 to 33 for each parallel, we finally obtain 400 for the number of direct measurements that have been used for the estimation of the following 270 normal values. parallels with 189 normal 19 be en as $F of XV= 3.42 — Ame sox {X =e E25 6.20% Xv=%9 + $.lb — 08k) yo. 60d 0.609 & F.0€ Lo + XV= v.ct -- z. en on es = 1.661 4.964 iS Sor { XV= ott — otb — = X = 9.258 7.626 a o6 { XV='S.61 — $17 — a X =21.848 £.1001 fe io} XV= 01 — Sz.gS + e sé ie = 0.108 $6.266 & a Xv= 05 + o.$ZL + a of {x = 7.0S+ 1.0L Pe 9 = $1 + Soz + Xv : of ie = g.4of v.61€ < = n 5 X =S9.£07 g.£b1 < o = fo = $.of — Xv a be Us = f.rbx 6.Lz I n Le —EE ——— a © ‘\Y= ,ozt + 08Z * 00% $.6g g.26z 1.091 S.£99 S.E% 4.936 $g.t9 SL.E104 0.gI v.b16 Lil S.£EL 0.17 0.L69 So.0f $6.52 S£.z Sr.LLE + + “oS 9F 6.37 + V.%% 6.671 — 1.661 1.$or — L.¥6S 6.28 + £.0g6 6.0F + g.t901 Wea ¢.€fo1 *fhsoayy sausof ayy 0} Buyp.ooan sanjma ayy anogn sassaoxa way) 40 “XY fo pun vbr L.Iv1 €.S11 Z.78Z 9.27 S.LES $6.¢S Sr1.vfg 9.67 1.126 Sg.gt S1.gIo1 +.6 o.Sfg $9.0 SL.btg Z.71 t.SQv £.2z L.gf& “98 + ‘spuaUodwuon 1D,UOZL.LOY UlIYpLOW aki pe | sgt 1.L9 Se \ets 6.909 =X Zt —=XV Lag =X } of 1.66L =X } S01 $$.65 +=yV $L.£99 =x } 06 S.gt —=XV 06.£g =X }se packs TEXT bos svg =X J $.g1 —=XV v.99 =x lot S.91 —=XV LSS = of 8.0 +=XV g.vot =X |e n hed =X ‘x fo samv4g ‘T “6681 BOL SINVISNOO NYISSOVH FHL FO NOWVIOdWOO THI 20k CHAUAS TAVH LVHL SINANATY ONANOV]L TVYNLON Sor { AY rt oSt { a" xk er 4 AY ovr x eM K 06 i oo A Ps mo SL ee BH 2 OG ie = x eI AV +b e ‘2 AV of ie AV te {x n x Il I pus oad +r ++ ++ o om ++ ++ ww ++ 4+] *,08z *,obz i=) mR S.bzr+ S.zgi— 2.76 + L.o$1— £6 + £.gS1— g.1zZ — Z.b¢1— a V.ob1— f.gz + S.gh1 — rare + 0.0gI— L.ge — 2.087% — 7.61 — 7.L61— 9.9% — S.zgi— ° * 007 f.o1 — Z.gS — 6.65 — LSz1— ibe — 0.691 — giz — f.zgi— SE.gr — Sz.bSit— $6 + 6.16 — 0.0 7.64 — 6.61 — 8-08 — ° “9091 @ i+ ++ +1 ww SNS +H i w + + + ++ ++ ++ pee aa +a [et *, 071 “08 I+ ++ +1 Pos Z.0TI — b.zb —=xV F oble+ Liti+-= gt ZS — So —=XV £.628+ | f.0L1+=% } oss Ig — 021 +=XV £.€97+ .lez+ = } o€t £.62 — 0.0% —=XV g.-boz-+ L.g9gz+ = | $or f.1r + $9.9 +=KXV oS 617+ So.gzf+ = | 06 g.of + S.€ +=xXV SZ 0.£07+ £.0ff£+ = 0.0 1.£4 —=xV F g.£g + o.z61-=K [° St.ér — 6.02 —=xXV S$.08 + ene” | ob 1.6 — g.Z —-=iXV ale fr + LL4L1+=% f.22 — 6.Lz Peay bz Ig — L.8gi-+= 5 ° ° n * oF "50 =Y *fsoayy dausof ay 02 burp.sovn sanjna wayp anogn sassaoxa ayn 40 ‘KY fo pun ‘syuauodwuoo yavozoy Uutajsam to *K fo sanyng “TT 21 ON THE GAUSSIAN CONSTANTS FOR THE YEAR 1829, oS ov of £z ° n "haoryy sarusof oy 02 Burp.coso sanynn ay anoqn sassaaxa ayy 40 “ZV fo pun ‘syuauodwuoa nortan 10 ‘y fo sng “TIT (oe ae ES ae SS re) Sa ——S £.$9 + Z = o.losir— ZV= 9-81 — Z = 9.9b11— ATi — en oe 6.979 — ZV= v.1et + Z= vee + Zv=S2.56 — Z =So.bbv + bs ll = + ie} oO + N NN NN — Z.7t + zlgo + Cir $.096 + for — +.Soz1+ $.L5 — f.gbf1+ 0.96 — €.9Sbi+ ° *,0v 22 REPORT—1872. We give now the result of our investigation, viz. the Gaussian constants for 1829, as resulting from all observations that we have found or made avail- able for the purpose, and thereby forming the best theoretical representation of terrestrial magnetism which we think can up to the present be effected. The probable error that is subjoined to each of these numbers shows to what extent it may be relied upon; but as these valuations are only founded on the differences between the values that were assumed for our 270 normal elements and those which the new constants assign to the same, the mean of their amount may perhaps be still altered by the more numerous comparisons of directly observed and newly calculated elements that will soon be instituted and published. The Gaussian constants for 1829, and their probable errors. Names, | Vi'onventional units,” | Probable of the Gaussian theory*. yee g +916:041 179 ei + 81144 2°97 ee —172°030 2°32 ee + 3°463 2°04 2°1 —127°463 3°92 we + 2060 3°08 oS + 3°575 2°61 ata — 36167 1°03 ae — 53°699 5°41 os + 357466 4°24 he? + 47:069 4°60 Te — 87°942 7°44, }3°2 aes 17°776 1°82 3°3 ma 3°640 073 733 ae 20°744 0°58 g* — 78°353 4°83 Ley —109'919 8°63 a — 9150 6°97 {58 — 44624 7°44 Ss + 31054 2°95 g + 19°198 1°67 i + 8627 1°31 Fa + 2°561 0°54 hae ae + 3173 +068 The derivation of the most interesting consequences of these numerical results and a complete comparison of observed magnetic elements with both their representations by the old and by the newly founded theory being deferred for. the moment, in the mean time the following shows the effect of our performance for those parallels that were especially considered. * Hach=0'00349412 German unit of absolute gente =0°0075781 English = Fe 3 ON THE EXTINCT BIRDS OF THE MASCARENE ISLANDS. Means of probable errors. On the Of the old | Of the new) Of the old theoretic | theoretic | theoretic Nene evaluation | evaluation | evaluation i of the X. | of the X. | of the Y. | 23 serass8 |) rqeg2 | te17°28 30 12°06 18°04 5°67 40 19°71 23°77 16°25 50 29°43 22°56 18°97 75 19°14 21°55 22°02 go 32°43 22°70 18°76 105 26°05 19°06 12°90 130 53°48 25°67 16°46 150 53°88 22°98 44°86 165 42°38 +2129 60°51 On average Eee sbe141 +2843 23 Of the new theoretic evaluation of the Y. 12°98 8°71 393 15°29 17°82 1o°I2 16°32 10°43 23595 21°49 15°98 Of the old theoretic evaluation of the Z. Of the new theoretic evaluation of the Z. 30°34 28°32 28°95 32°44 29°00 34°16 33:25 The new elements of theory have therefore lessened the probable errors Of the X. Of the Y. to to On average... 0°64.12 0°5612 of their former value. | of their former value. And on the to to parallel to O°5012 0°3552 u=165° of their former value. | of their former value. o'r 5 of their former value. Of the Z. to _0°5539 of their former value. to 2 Berlin, February 29th, 1872. Second Supplementary Report on the Extinct Birds of the Mascarene Islands. By Aurrep Newron, M.4A., F.R.S. Tux small portion of the grant so liberally voted by the Association at the Birmingham Meeting in 1865, to aid my brother Mr, Edward Newton in his researches into the extinct birds of the Mascarene Islands, which remained unexpended at the time of my last reporting his progress, has during the last year or so been employed by him in a renewed examination of the caves in the island of Rodriguez, which had already produced so much of interest. 24 REPORT—13879. This examination has been conducted, as before, by Mr. George Jenner, lately the chief executive officer of the island ; and though I am not in a position to give any thing like a detailed account of the results, [am happy to say that I believe they will be found in time to be fully as instructive as those of the former examination have been. We are now in possession of several parts of the skeleton of Pezophaps which have hitherto been wanting, and of more perfect specimens of some of those bones which we before obtained. We have also additional remains of the large Psittacine bird, described from a single fragmentary maxilla by Prof. Alphonse Milne-Edwards as Psittacus (?) rodericanus ; and this, I hope, will enable that accomplished palzontologist to determine more particularly the affinities of the species, which have hitherto been doubtful; and I may add that thus some further light may be thrown upon the position of the P. mauritianus of Prof. Owen. In the course of last year my brother had the pleasure of receiving from Mr. Jenner proof of the continued existence of one of the species described by Leguat as in- habiting Rodriguez, but thought to have become extinct. This proof con- sisted of a specimen procured in spirit of an undescribed and very distinct Paleornis, which I have since described (Ibis, 1872, p. 33) as P. ewsul. Among the bones sent by Mr. Jenner are, I believe, some which belonged to this bird. But more remarkable and interesting still are some remains which are obviously those of a Ralline bird, unquestionably allied to Ocydromus ; and these M. Alphonse Milne-Edwards informs me he is inclined to refer to the “ Gelinotte” mentioned by Leguat, the nature of which has hitherto been only open to guess. There are also bones of other species of birds, perhaps only inferior to this in interest. Most of these specimens have been intrusted to the care of M. Alphonse Milne-Edwards ; for my brother and I believe that the distinguished author of the ‘Oiseaux Fossiles de la France’ has established a claim upon the assistance of all who are interested in extinct ornithology by that admirable work of his; and I learn from him that he will shortly make public the results of these recent discoveries. Report of the Committee for Superintending the Monthly Reports of the Progress of Chemistry, consisting of Professor A. W. WILLIAM- son, /.R.S., Professor Franxianp, F.R.S., and Professor Roscor, F.R.S. Durine the current year the Chemical Society has continued the publication of the monthly reports of the progress of Chemistry, which had been com- menced last year with the aid of the British Association. The labour of preparing these Reports is considerable ; and it is due to the chemists who perform that arduous duty to acknowledge the great care which is bestowed upon it by them for a remuneration scarcely more than nominal. It has been found necessary, in view of the very great number of chemical papers, to render the reports very brief, so as to convey a knowledge of the general results of each paper without giving the details of evidence. The Members of the Committee have had the pleasure of noticing that the reports are considerably valued by English chemists; and there is reason to believe that the anticipations which were formed of their usefulness in pro- moting the advancement of chemistry will be fully realized. UNIFORMITY OF WEIGHTS AND MEASURES. 25 Report on the best means of providing for a Uniformity of Weights and Measures, with reference to the Interests of Science, by a Com- mittee consisting of Sir Joun Bowrine, F.R.S., The Right Hon. Sir Starrorp H. Norrucors, C.B., M.P., The Right Hon. Sir C. B. Apperuey, M.P., Samurt Brown, F.S.S., Dr. Farr, F.R.S., Frank P. Fetiowes, Professor Franxuianp, F.R.S., James Hey- woop, F.R.S., Professor Lrons Levi, F.S.A., F.S.S.,C. W. SteMEns, F.R.S., Professor A. W. Wituramson, F.R.S., Dr. Georcr GLover, Sir JosrerpH Wuitwortn, Bart., F.R.S., J. R. Narrer, J. V.N. BazaLcerte, and Sir W. Farrparrn, Bart., F_R.S. Tue Metric Committee of the British Association have much pleasure in reporting that another great stride has been made towards the attainment of uniformity in the Weights, Measures, and Coins of all countries by the passing of a law in Austria, in. June 1871, rendering the use of Metric Weights and Measures permissive from the 1st of January, 1873, and compulsory from the 1st of January, 1876. The Metric System is gradually diffusing itself all over Europe. At this moment fully two thirds of that Continent, measured by population, have adopted the Metric System of Weights and Measures, and the other third has manifested sufficient interest in the question to justify the expectation of its early adhesion to the general agreement: but in this third there are comprised Russia and England, two countries which, by their popu- lation and commerce, exercise an enormous influence in the whole world. The state of the question in Russia appears to be as follows:—In 1859 a Committee of the Imperial Academy of Russia, consisting of the Academicians Ostrogradski, Jacobi, and Kupffer, issued a report on the subject, which approved of the decimal division already incorporated in the Russian System, the rouble being divided into 100 kopecks, the vedro into 10 krouchki, and the inch into 10 lines, and expressed an opinion in favour of extending such decimal divisions to Weights and Measures. In discussing, however, the possibility of even this moderate reform, the Academicians saw that a very considerable change would be required. Supposing the foot were retained as a unit, how could it be decimalized without abandoning altogether such divisions as the archine, which is 23, and the sagene, which is 7 feet? Yet these are really more in use than the foot itself. And what multiples could be adopted? The foot of Russia, which is identical with that of England, is too small to measure cloth by, and 10 feet would be too large a unit. With such difficulties attending the decimalization of the existing Weights and Measures, the Academicians felt that it would be far better for Russia at once to introduce the Metric System; and this was the conclusion of their recommendations. Since the publication of this Report, the Imperial Academy of Russia has taken an active part in the advance of the system all over the world. In 1867 M. Jacobi was a Member of the International Committee on Weights, Measures, and Coins in connexion with the Paris International Exhibition, and wrote the report which was agreed to by the representatives of all the nations who took part in the Conference on the subject. And later still, in 1870, on the representation of the Imperial Academy of Russia to the French Government and to the scientific bodies of other nations of the need of preparing more accurate and uniform Metric Standards for the use of countries which might adopt the Metric System, an International Commission was appointed to prepare such Standards. This Commission met in Paris in June 1870, and is about to resume its labours 1872. D 26 REPORT—1872. in September next. These steps on the part of the Imperial Academy of Russia have not been followed by legislative action; yet, when we consider the just influence which the Academy exercises in a subject of this nature, it is reasonable to anticipate that their recommendations will be duly heeded, and that as soon as the Standards are completed the Russian Government will take into consideration the necessary steps for introducing the Metric System, whereby the Weights and Measures of Russia may be rendered iden- tical with those of the greater number of European nations. In the United Kingdom considerable progress has been made towards the introduction of the Metric System, though much certainly remains to be done. In 1862 a Committee of the House of Commons was appointed to consider the practicability of adopting a simple and uniform system of Weights and Measures, with a view not only to the benefit of our internal trade, but to facilitate our trade and intercourse with foreign countries. In discussing the question of the possible decimalization of the existing system, the Committee of the British House of Commons, in the same manner as the Committee of the Imperial Academy of Russia, reported that it would involve almost as much difficulty to create a special decimal system of our own as simply to adopt the Metric Decimal System in common with other nations ; and under these circumstances the Committee came to a unanimous recom- mendation in favour of the introduction of the Metric System. Accordingly in 1864 an Act was passed to render permissive the use of such Weights and Measures so far as to legalize contracts made in terms of Metric Weights and Measures, which were heretofore prohibited ; but no pro- vision having been made for obtaining correct Standards whereby to verify the same, the use of the System in shops was not thereby permitted. A Royal Commission has, however, inquired into the question on the Metric Weights and Measures of the United Kingdom; and after considerable in- quiry it issued a report recommending the preparation of such Standards and the removal of every difficulty which may yet exist in the way of the permissive use of Metric Weights and Measures. We may therefore hope that Her Majesty’s Government will speedily bring forward a measure for carrying the recommendation of the Commissioners into effect. The appended map of Europe (Plate I.) shows how extensively the Metric System is already used. If once Russia and England should finally place their legislation on the same footing, other States will certainly follow, and in Europe, at least, we shall have attained perfect unity as regards Weights and Measures. But in other parts of the world also considerable progress has been made. In Asia the whole of India may be said to have adopted the Weights and Mea- sures of capacity of the Metric System, though some time may elapse before the Act passed by the Indian Government can be carried into operation. In America the United States have introduced it permissively, whilst Brazil, Chili, Mexico, New Granada, and other American republics have adopted the Metric System absolutely. Throughout the world as many as 213,000,000 of people have adopted it absolutely, 160,000,000 more Me Sas and 70,000,000 per- missively, giving a total of 443, ‘000, 000. Nor has there been less done as regards the coinage. If we compare the coins now in use all over the world with those in use some twenty years ago, it will be seen what advance we have already made everywhere towards unity. Some countries, such as France, Italy, Switzerland, Belgium, Greece, and _ Roumania, have already an identical system of coinage secured to them by the Coinage Convention of the 23rd of December, 1865. The Austro-Hun- garian Empire issues gold pieces marked 20 florins and 8 florins, equal to 10 Report British Association 30 IE UIRO FP SHEWING THE COUNTRIES WHICH HA METRIC SYSTEM OF WEIGHTS i AND ALSO A SYSTEM OF COINAG THE MULTIPLES OF THE 5 F Goontries marked YB have adopted the Me} Gartries marked [=A have adopted it per Gartries marked TI have adopted it pd Goartries colored Yellow have also 5 Francs, Austria having coins equivale Swederv cows equivalent: to 10 Francs, the Franc System Plate 7, Population. of the World which have adopted the Metric System. Absolutely._.....243,000,000. \ Partially... 160,000, 000. \ Permusstvely.__.. 70,000,000. \ 443,000,000. \ \ 40 EW RO PIE SHEWING THE COUNTRIES WHICH HAVE ADOPTED THE METRIC SYSTEM OF WEIGHTS & MEASURES AND ALSO A SYSTEM OF COINAGE BASED OW THE MULTIPLES OF THE 5 FRANC PIECE (mma mrt Ihre and ha Mir Spt of Wighis dt Meares abel Populauion of the World hich have Cort nk hare dip it perma ‘adopted the Metric System Commi toad TD om api st parcial | Absolutely 213,000,000. Cures cokared. Ville hewn alse achepsinc 1, Crinagye based om the ralinplas of Purtially, 160, 000, 000. Fre, Aan hang one eppralnt tw 10 France & 3 France “Soudan cine similar 10 Prams, the thar Cninervne the Caine of } UNIFORMITY OF WEIGHTS AND MEASURES. ref 25 frances and 10 francs respectively. Spain issues gold pieces of 25 pecetas, equal to the 25-franc pieces ; and Sweden the caroline, equal to 10 francs. The Committee much regret that the German Empire, which had recently a most favourable opportunity for extending the desired uniformity (an object to which she has shown her adherence by the recent adoption of the Metric System), has issued a new gold coinage having nothing in common either with the money of the Convention of France, Switzerland, Italy, Belgium, or with the monetary systems of England or the United States. It is much to be desired that we should clearly understand the points on which a common _ accord exists in matters of international coinage. There is a general agree- ment on the advantage of a complete decimal system, on the adoption of the fineness at nine tenths fine and one tenth alloy; and the greatest number of States agree also on the adoption of gold as the only standard of value. Between the three leading systems of the world, founded respectively on the France, the Dollar, and the Pound Sterling, a point of contact has been found in the 5-frane picce and its multiples, the 5, 10, 20, and 25-frane pieces; and considerable agreement has already been obtained in this method of approach- ing the question. Your Committee would look forward to a much greater identity of coinage being ultimately realized than would be obtained by this method; but it should be remembered that even the universal acceptance of this plan would immensely simplify the relations of coinage between the different nations, and of necessity lead to a more identical system. During last year your Committee have had communications with the Indian Government on the question of introducing the Metric System of Weights and Measures in India, the original Act by which all the Weights and Measures of the System were introduced having been vetoed by the Home Government, and another, limited to Weights and Measures of capacity, having been passed in its stead. In England the action of the Committee has been most influ- ential, especially in connexion with education, It was at the instance of this Committee that the Committee of Her Majesty’s Privy Council on Education have inserted in the Code a clause requiring that instruction on the Metric Weights and Measures shall be given in the Elementary Schools in the King- dom. And in order to stimulate education on the subject, to explain the general character of the Metric System and its relation to the Imperial, and to indicate the advantages which would result from an International System of Weights and Measures, your Committee have granted to the British and Foreign Schools, the National Schools, the Wesleyan Schools, and the Con- gregational Schools in England, as well as to the National Schools in Ireland, copies of Books and Diagrams on the Metric System, which have been grate- fully received. The Committee were anxious to purchase a set of Metric Standards, as stated in their last Report, for the purpose of illustrating lectures and papers on the subject; but they found that while their cost would have absorbed nearly the whole vote, it would have been impossible to lend out such standards without endangering their preservation. In January 1872 a public meeting was held at the Mansion House, under the presidency of Sir John Bennett, Sheriff of London, when resolutions were passed in favour of the early introduction of the Metric System of Weights and Measures and the Decimal Division generally. At this meeting Sir John _ Lubbock, F.R.S., General Strachey, of the India House, the Rey. William \ Jowitt, Dr. Farr, F.R.S., the Hon. N. G. Northope, Superintendent of Public ‘Instruction in the United States, the Hon. Mr. Ryan, of the Canadian Senate, and other persons of distinction took part. ‘The unification of the Weights, Measures, and Coins all over the world is D2 28 REPORT—1872. fraught with immense benefit to science, commerce, and civilization, and philo- sophical and scientific bodies of all nations have given their adhesion to it; the commercial classes look to such unification as an essential element in the eco- nomy of time and the performance of international works, and travellers all over the world regard it as the greatest boon that could be conferred. Towards the attainment of this important object, the Metric Committee of the British Association for the Advancement of Science have exercised an important in- fluence ; and they trust that if they are allowed to continue their action for a few years longer, they will be able to report the recognition all over the world of the principle for the promotion of which they were appointed. In conclusion, your Committee recommend their reappointment. Eighth Report of the Committee for Exploring Kent’s Cavern, Devon- shire, the Committee consisting of Sir Cuartes Lyset, Bart., F.R.S., Professor Puituies, F.R.S., Sir Joun Lussocn, Bart., F.R.S., Joun Evans, F.R.S., Epwarp Vivian, M.A., GrorcE Busk, F.R.S., Witttam Boyp Dawkins, F.R.S., Witt1am Aysu- FORD SanrorD, F.G.S., and Witu1aM Pence tty, F.R.S. (Reporter). In commencing this, their Eighth Report, the Committee have to state that since their last Report was sent in (Edinburgh, 1871) the excavations have been carried on by the same workmen, without interruption, and in all respects in the same manner as in former years. The visitors to the Cavern have continued to be very numerous. Amongst those accompanied by the Superintendents, the following may be mentioned :— The Emperor Napoleon III., the Prince Murat, the Prince and Princess of Oldenberg, Sir W. Jardine, Bart., Sir W. Topham, Rey. M. Brown, Rev. G. Buckle, Rev. Mr. Drewe, Rev. Dr. MacGregor, Rey. F. A. Saville, Rev. W. Thompson, Rey. H. H. Winwood, A. D. W. R. B. Cochrane, M.P., W. H. Smith, M.P., General Freeze, C.B., R.A., Colonel Naylor, Colonel W. Pinney, Captain S. P. Oliver, R.A., Professor F. Roemer, of Breslau, Professor A. Newton, Dr. Bond, Dr. Hounsell, Dr. Schmidt, of Essen, Rhenish Prussia, and Messrs. Bosanquet, H. H. Bothamley, W. R. A. Boyle, — Chaplin, B. J. M. Donne, W. Fenner, R. Gwatkin, J. Holdsworth, J. H. Parsons, E. C. Robson, — Stewart, J. Stilwell, G. C. Swayne, E. B. Tawney, B. Tower, — Waldegrave, W. Vicary, I. Whitwell, and A. W. Wills. The Cavern has also been visited by the Exeter Naturalists’ Club, and by a large party of Members of the British Medical Association, at the close of the Annual Meeting at Plymouth in August 1871, including Rey. Professor Haughton, Professor Lister, Dr. Crossby, of Nice, Dr. A. Godson, Dr, Lang, Dr. Macnamara, Dr. Murphy, Dr. W. Roberts, and Mr. Wilde. Visitors of a much less welcome character have also been numerous during the year. In February last the workmen somewhat frequently observed several large rats running about the Cavern, but for some time failed in all their efforts to capture them. One morning one of the men, on commencing his work, wrapped his dinner-bag in the coat he had just taken off, and put the whole carefully aside. At dinner-time the coat was found to be eaten through, and the bag with its contents was gone. A few days after, the other man, having taken his dinner, placed his bag, containing a piece of bread, in a basket, and fastened the cover. On leaying work, he found a hole had been ON KENT’S CAVERN, DEVONSHIRE. 29 eaten through the basket, the bag was torn into the merest shreds, and the bread was gone. Thus stimulated, the men baited their traps with great care, and had the pleasure of catching seven or eight rats. No further annoyance was experienced until July, when a large rat was seen to enter the Cavern about midday. The poor wretch was found dead in the trap in a day or two. During the last twelve months the Committee have explored the branches of the “ Western Division” of the Cavern known as “The Wolf's Cave,” -« The Cave of Rodentia,” and “The Charcoal Cave,” and have commenced “The Long Arcade.” The Wolf’s Cave.—That branch of the Cavern which extends in a northerly direction from “The Sloping Chamber” was, by Mr. MacEnery, termed “The Wolf’s Cave,” and occasionally “The Idol Cave”*. It received the latter name from “a column of spar” which, “ near its entrance, joined the ceiling and floor and obstructed the way,” and “had a singular resemblance to a Hindoo Idol” +; and the former, because, on the removal of this “ column,” it was found to have “covered the head of a wolf, perhaps the largest and finest skull, whether fossil or modern, of that animal in the world ” t. Mr. MacEnery seems to have been eminently successful in collecting speci- mens in this branch of the Cavern; for he states that “ of the quantity and condition of the remains here it is scarcely possible to give a just idea with- out appearing to exaggerate. They were so thickly packed together that, to avoid injuring them, we were obliged to lay aside the picks and to grub them out with our fingers. They were found driven into the interstices of the opposite wall, or piled in the greatest confusion against its sides, with but a scanty covering of soil, and that of the finest and softest sand intermixed with greasy earth. To enumerate the amount of fossils collected from this spot would be to give the inventory of half my collection, comprising all the genera and their species, including the cultridens. There were hoards.” Here, too, he appears to have found all the remains of Machairodus latidens (known then as Ursus cultridens) the Cavern yielded him, which he states were five canines and one incisor§. When completely excavated to the depth of 4 feet below the base of the Stalagmitic Floor, this Cave was found to extend nearly 70 feet in a north- westerly direction, and at its entrance, or junction with the Sloping Chamber, to be about 40 feet wide. At3 yards inside the entrance it narrows to about 20 feet, at 7 yards to 10 feet, and beyond this its general width is from 7 to 8 feet ||. Its present height is about 7 feet throughout; but before the com- mencement of Mr. MacEnery’s diggings, the space between the Limestone Roof and the Stalagmitic Floor could nowhere have exceeded 2 feet, even if the latter had been entirely free from rubbish. Indeed he states that when they first entered this branch, he and his companions “ crawled like tortoises ” 4]. At the entrance the Roof is commonly fretted as if by the action of acidu- lated water; but here and there, and especially on the eastern side, its com- paratively fresh and smooth aspect indicates what may be termed the recent fall of masses of limestone from it,—an indication confirmed by the presence of such masses, some of them of great dimensions, immediately below. At intervals throughout the entire length of the Cave transverse lines of frac- ture, or divisional planes, appear in the Roof: some of them are close-fitting, * He also spoke of it sometimes as ‘‘ The Wolf’s Passage” and ‘‘ The Wolf's Grave.” + See Tr. Devon. Assoc. vol. iii. pp. 248, 293 (1869). { Ib.p.243. — § Ib. pp. 369, 370. || The breadth is always measured at the level of the surface of the Cave-earth. In this Cave it was invariably narrower at the bottom of the excavation. §] See Trans. Devon. Assoc. vol. iii. p. 292. 30 REPORT—1872. but occasionally they have been corroded or fretted into cavities of rudely elliptical outline, from a foot to 2 feet in height. The largest of them measures 5 feet long and something less than 1 foot wide; its walls are much fretted, and numerous pipe-like stalactites depend from its roof. Some of the holes are completely lined with stalactite, whilst others are quite bare. There are no traces of Cave-earth in any of them. The north-eastern wall of the Cave, from the entrance to nearly 30 feet within it, is a confused mass of large fallen blocks of limestone. With this excep- tion, the walls, as in the other branches of the Cavern, consist of beds of limestone in situ. They are not much fretted, their edges are all more or” less angular, and they are here and there traversed by fissures corresponding with the lines of fracture in the Roof. From the considerable remnants left undisturbed by Mr. MacEnery, there was, no doubt, a continuous “‘ Granular Stalagmitic Floor” from end to end. It seems to have varied from 3 to 12 inches in thickness, and to have possessed the granular and laminated structure characteristic of the Floor covering the “ Cave-earth.” In a large area at the south-eastern angle of the Cave the Floor had been left untouched, and was found to be in some eases fully 2 feet thick. Like that in a great part of the adjacent Sloping Chamber, of which it is a prolongation, it contained numerous large masses of limestone and of the “Old Crystalline Stalagmitic Floor” so frequently mentioned in former Reports. Similar masses, of both kinds, were abundant in the Caye-earth below the Floor in the area just mentioned; and in some instances the blocks of lime- stone lay across one another with but little deposit between them, as if they had fallen after the accumulation of Cave-earth had ceased. In a few in- stances the cavities or interspaces were not covered with the Stalagmite, and some of them contained a few recent bones and other objects. Omitting this south-eastern area, Mr. MacEnery extended his researches quite to the innermost point of the Cave, and, with few exceptions, up to 13 feet from the entrance, had broken up and searched the entire deposit to a depth exceeding the Committee’s four-feet sections. Within the point just specified, he contented himself with cutting a comparatively narrow trench, leaving the ground quite intact adjacent to, and a few feet from, the south- western wall, but, as before, carrying his excavations to a depth exceeding 4 feet. At 24 feet from the entrance, however, he dug to no greater depth than 2 feet, and very rarely exceeded this in the inner part of the Cave,—thus leaving the Committee’s third and fourth foot-levels everywhere intact, besides the belt adjacent to the south-western wall, of which, as already mentioned, no portion was touched. This margin, it may be presumed, was left intact in consequence of all the excavated material being lodged on it. No portion of the latter appears to have been taken out of the Cave. The deposit the Committee found in the Wolf's Cave, whether disturbed or undisturbed, was well-marked typical Cave-earth, consisting of red loam with about 50 per cent. of angular fragments of limestone. There were no traces of the older deposit termed “ Breccia” in previous Reports, either in situ or redeposited, and, excepting the area in the south-eastern corner, already mentioned, no fragments of the Old Crystalline Stalagmitie Floor. In proceeding to the objects found in the Wolf’s Cave, it is obvious that nothing can be said about such as may have been on or in the Stalagmitic Floor; they, if such there were, had no doubt been seeured by the earlier explorers. It has already been stated that there were occasional interspaces among ON KENT’S CAVERN, DEVONSHIRE. 31 the blocks of limestone lying confusedly in the south-eastern portion of the Cave. In some of these, all of them being sealed up with Stalagmite, shells of the common Pecten (Pecten maximus, Linn.) were found, amounting to a total of twenty-five. Most of them were large shells, and some were thickly incrusted with calcareous matter containing, in one or two cases, traces of charred wood. In one instance two, and in another five, shells were found fitted neatly into one another, and cemented together with carbonate of lime, thus leaving no doubt that man had not only packed them, but placed them where they were found. The fact that some of them were ‘dead shells,” having Serpul attached to their inner surfaces, indicates, of course, that they were not in all cases taken to the Cavern because they contained an article of food, but probably sometimes, at least, as domestic vessels, The undisturbed Cave-earth in this branch of the Cavern yielded a con- siderable number of the remains of the ordinary Cave-mammals, including nearly sixty shells, which may be distributed as in the following Table :— Taste I.—Showing how many per cent. of the Teeth found in Cave-earth in the Wolf’s Cave belonged to the different kinds of Mammals. Miyenbis eos 6. 44-5 per cent. | Elephant ........ 2°5 per cent. IEROTSE? of Nios oe 25 3 intone SFI GM 1 a Rhinoceros ...... 15 es Nia) eS cs epee 1 Ba Megaceros ...... 3 a OxB see Se ee al 3 ener ee Re o, 3 3 Rabbit. ha 2s.) 5) a Meer. A BS amare Bonite PO OU aw only 1 tooth. It will be remembered that the Cave-earth is excavated in vertical slices or “Parallels” extending generally from wall to wall of the branch of the Cavern under exploration, to a depth of 4 feet and a horizontal thickness of 1 foot ; that each Parallel is taken out in 4 successive “ Levels,” each a foot in vertical depth; and each Level in “ Yards,” or masses 3 feet in length. From what has been already stated, it is obvious that in the Wolf’s Cave there were no continuous first or second Foot-levels intact, and that even the third and fourth were not everywhere met with. Confining attention to the twenty-one instances of each of the two latter which did occur in the same Parallels, the following Table will show the distribution of the teeth of the various kinds of Mammals in them :-— Taste 11.—Showing the distribution of the Teeth of the different kinds of Mammals in the third and fourth Foot-levels of twenty-one Parallels of Cave-earth in the Wolf’s Cave. 3 a Lis] 2 a eiflelselelaisiealal. ml ole |/o2/S/8)2).2) 0] Hitialsialimlielaialo No. of Parallels containing teeth in 3rd Level... 16/12) 9| 2)}4)}4);0/2/0)/1 " i ‘ h,, | 1614/15; 2}212)1)/ 2/1} i ‘ both Levels! 19118/18/ 3/6|6|1/4/1|1 BG Woof tenth, in SelDeavel (. 62s cac. cas. :s--c 63 24/11/13; 4/4/0/ 2/2] 1 : 2 aR ie 6829/21) 3}2/2|5\2/0\1 4 cate a1 oe Tail63/s2\ie|6|6l5|4)/2/2 32 REPORT—1872. The following examples will serve to explain Table II.:—Teeth of hysna occurred in the third Foot-level in 16 distinct Parallels, and in the same number in the fourth ; but as they were met with in a total number of 19 Parallels only, it is obvious that in 13 instances (= 16 + 16 —19) they occurred in both levels in the same Parallel. Again, as the Table comprehends 21 Parallels, and teeth of hyena were found in 19 only, it follows that there were 2 Parallels (=21—19) in which no teeth of this genus presented themselves. Further, a total of 131 teeth of hyzna were exhumed in the 19 Parallels, and of these 63 were in the third Foot-level, and 68 in the fourth or lowest ; hence the different Levels were almost equally rich, and on the average several teeth occurred in one and the same Level and Parallel. To take another example:—Teeth of bear were found in the third Foot-level in 4 Parallels, and in the fourth Foot-level in 2; but as they occurred in a total number of 6 Parallels, it is obvious that in no in- stance were they met with in both Levels in one and the same Parallel (44+2—6=0). Again, as the Table comprehends 21 Parallels, and teeth of bear were found in 6 only, it follows that there were 15 Parallels (21—6=15) in which no teeth of this genus presented themselves. Further, a total of 6 teeth of bear were exhumed in the 6 Parallels, and of these 4 were in the third Level and 2 in the fourth or lowest; hence the third was the richest Level, if the slender evidence may be trusted; and the teeth occurred singly, no more than one having in any instance been found in the same Parallel. It is perhaps noteworthy that whilst teeth of rabbit and fox occurred in the Wolf’s Cave, as is shown in Table I., they did not, according to Table IL., present themselves in either the third or fourth Level. As in previous years, the Committee have removed and examined the deposits dug up and thrown aside by Mr. MacEnery. In the Wolf's Cave, as elsewhere, this material yielded a large number of the remains of the ordinary Cave-mammals, including about 350 teeth, which may be thus apportioned :— Taste IJI.—Showing how many per cent. of the Teeth found in the disturbed material in the Wolf’s Cave belonged to the different kinds of Mammals. PRONA 5. ss Acie ead 36 percent. | Bear ...... 1:5 per cent. SHIOTS@ ayers sn. coi = 33°5 - Deer cok. sas 15 35 Rhinoceros ...... 19 “a Badger .... 1:5 a Megaceros ...+.. 3 “ Oa aa as less than 1 per cent. SHEED sheik osts os 2 Mg Dione ee be ”? Though it would be utterly useless to compare Tables I. and III., since the latter includes teeth not only from all Levels, but possibly such as were lying on the Stalagmitic Floor, as well, perhaps, as more recent introductions, it is not without interest to observe that even amongst the rejected or neglected specimens, as the case may be, as well as in the undisturbed Cave-earth in every branch of the Cavern, the most prevalent forms are hyzna, horse, and rhinoceros, and that their relative prevalence is indicated by the order in which they have been named. The bones and teeth present much the same characters as those found in previous years. Thus, many of the latter are in jaws or fragments of jaws, destitute, as usual, of their condyles, and, in most cases, of the lower borders ee Se ON KENT’S CAVERN, DEVONSHIRE. 33 also. Most of the specimens have an almost white colour, but some are of a dark hue; some are more or less coated with stalagmite, some are broken, some split, and very few have escaped the teeth of the hyena. Amongst the finer and more remarkable specimens may be mentioned jaws of hyena, canines of lion and bear, a left lower molar of Hlephas primigenius, part of left lower jaw of rhinoceros, and a portion of a palate and both upper jaws of megaceros. One of the canines of bear (No. 5537) is so peculiarly worn or cut, both on the crown and on the fang, and especially the latter, as to suggest the probability of human agency. -On account of its strange aspect it was for- warded to Mr. G. Busk, President of the Royal College of Surgeons, F.R.S., V.P.L.S., &c., a member of the Committee, who thus remarks on it :—‘‘ The bear’s canine (5537) is certainly very curiously worn if it be naturally so. The wearing of the crown part is possible enough, perhaps; but I cannot account for the apparently worn portion of the fang, which, of course, during life must have been protected from wear. But what could be the object of such an implement if it were manufactured? Perhaps a kind of gouge or chisel.’”’—(Signed) Grorce Busk. The mammoth’s grinder (No. 5575) is almost perfect. Its crown measures 6 inches in length and 2°5 inches in greatest breadth. It was found Sep- tember 13, 1871, in the third Foot-level, with 22 teeth of hyena in parts of 5 jaws, 2 of rhinoceros, 1 of bear, with several large bones and fragments of bone. The bear’s tooth just mentioned was a canine worn almost to the fang, which measures 1-7 inch in width. The rhinoceros jaw (No. 5562), which has lost its condyles, but not its lower border, contains 4 consecutive molars, and is quite the finest specimen of the kind met with by the Committee. It was found September 2, 1871, in the third Level, with a tooth of bear, bones, and fragments of bone. The jaws and palate of megaceros (No. 5646) contain 6 consecutive molars on the left side, and 5 on the right. This specimen was found October 10, 1871, in the third Level, with 1 tooth of rhinoceros, 1 of megaceros, 5 of horse, 6 of hynza in parts of 2 jaws, bones, and splinters of bone. Though Mr. MacEnery was not so fortunate as to find any flint implements in the Wolf's Cave, the Committee met with 5; and 4 of them are amongst the best specimens the Cavern has yielded. No. 5563 is a white lanceolate implement, 2-8 inches long, 85 inch broad, and +2 inch thick. It has a strong subcentral longitudinal ridge on one surface, is slightly concave longitudinally and convex transversely on the other, reduced to an edge on both margins, rounded and rather blunt at one end, abruptly truncated at the other, and has apparently seen some service. It was found September 2, 1871, in the fourth Level, with 1 tooth of bear, 1 of rhinoceros, 3 of hyzena, 3 of horse, and 1 of ox. No. 5571 is a pale grey flint implement of delicate proportions. It is 3-7 inches long, ‘65 inch in greatest breadth, and -1 inch in greatest thickness. It is longitudinally and transversely convex on one side, somewhat strongly concave lengthways, but slightly convex in the direction of its breadth on the other, has a long narrow oval form, three ridges on its convex side, a thin edge all round its perimeter except at one end which is rather blunt, and does not appear to have been used. It was found September 9, 1871, in the third Level, with 4 teeth of hyzna, 1 of rhinoceros, 1 of horse, 1 of ox, and frag- ments of bone scored with teeth-marks. No. 5592 is a chert implement, rudely quadrilateral i in form, 2:5 inches long, 2°2 inches broad, *6 inch thick, and has apparently been used. It was 34 - -REPORT—1872. found September 20, 1871, in the first Level, with 2 teeth of horse and 1 of rhinoceros. No. 5602 is a strongly proportioned chert lanceolate implement, 3°9 inches long, 1:1 inch broad, and -4 inch thick. It is concave on one face, very strongly carinated on the other, truncated at one end, pointed but blunt at the other, and worked to an edge along its two margins. It was found Sep- tember 22, 1871, in the fourth Level, with 4 teeth of hyzena, 2 of horse, and several fragments of bone. No. 5656 is a somewhat irregular ovate chert tool, unequally convex on its two faces, 4:2 inches long, 3°3 inches in greatest breadth, and ‘85 inch in greatest thickness, It has been wrought to an edge around its entire cir- cumference, but not elaborately finished; at one small part near its broader end a portion of the original surface of the nodule from which it was formed remains, and it has apparently been much used. It was found October 13, 1871, in the third Level, but without any bones or teeth in the same Yard. Three implements of the same type have been mentioned in previous Reports *. The Cave of Rodentia.—From the north-eastern corner of the Wolf’s Cave, a passage, scarcely 5 feet long, about 5:5 high, and where narrowest not more than 5 feet wide, leads into a chamber measuring about 25 feet from east to west, and 20 from north to south. It was termed the “ Cave of Rodentia” by Mr. MacEnery, who thus describes his researches in it :—‘“ We now found our- selves in the midst of hundreds of Rodentia. Of their remains and dust the deposit was constituted, agglutinated together by calcareous matter into a bony breccia. It should have been premised that the stalagmite above them was about a foot and a half deep, regularly laminated and free from all adyenti- tious matter. .... It suffered no disturbance or interruption from its first commencement. .... The remains of Rodentia were wanting in no part of the Cavern that we had yet examined, ... . but here, in this grotto, they swarmed in countless multitudes. Not only had their tiny remains penetra- ted into every cleft and crevice of the rock, but they insinuated themselves even into the chambers of the large bones. The wolf’s skull, in the passage, had its cavities charged and its surface incrusted over with a concretion of their bones... .. It was an interesting spectacle to behold myriads of minute animal remains congregated by the side of elephants, rhinoceroses, and hyenas in a common sepulchre. Heads generally crushed; lower jaws preserved. When a handful of this dust was thrown into water, hundreds of teeth rose to the surface, and it was by this means they were collected ” t. It will be seen from the foregoing quotation that here, too, the Committee were following Mr. MacEnery’s steps. His labours, however, were on a less extended scale than in the Wolf’s Cave. In the narrow trench to which he restricted himself, and which was not continuous, his excavations never extended more than 2 feet, and frequently not more than 18 inches, below the base of the Stalagmitic Floor. Connected with this Cave, more- over, there proved to be two recesses, which he did not enter; indeed he did not suspect their existence. The Roof of the Cave of Rodentia slopes gently towards the north. Its general height above the bottom of the Committee’s excavation is about 8 feet ; * See also ‘The Ancient Stone Implements, &c. of Great Britain,’ by John Evans, E.B.S., F.8.A., 1872, figs. 386, 387, p. 447. ft Trans. Devon. Assoc. vol. iii. pp. 244, 245. ON KENT’S CAVERN, DEVONSHIRE. 35 and from this it varies but little, except in one or two places, whence masses of limestone have recently fallen. The Roof is fretted, and has occasional flues, extending tortuously upwards, and from 9 to 12 inches in diameter at the bottom, where they are largest. None of them contain any stalactitie or earthy matter. The walls of the Cave are but little fretted, and their edges but slightly rounded. Almost immediately on entering the Cave the workmen had to blast a large mass of limestone lying on the Stalagmitic Floor, and which in all probability deterred Mr. MacEnery from breaking ground there. A few yards further in, a portion of the south wall, certainly in situ, and without obvious in- dication of severance from the limestone stratum of which it was a part, was found to project a few feet beyond the general direction, and to have Cave-earth beneath it. This underlying deposit had been regularly removed as the successive Parallels were excavated. At length the entire mass, estimated at a ton in weight, fell and very nearly crushed the principal workman. The Stalagmitic Floor, originally continuous across the entire length and breadth of the Cave, had in great part been broken up by the earlier explo- rers. Judging from the remnants of it still remaining, it was of the ordinary granular and laminated character, and from 3 to 12 inches in thickness. Beneath this Floor the deposit was the common Cave-earth from top to bottom of the 4-feet sections, except in the northern corner of the Cave, where the Old Crystalline Stalagmitic Floor, in situ, formed its basis, and rose like a boss from beneath. In the excavated deposits thrown aside in this Cave by Mr. MacEnery, the Committee found bones and teeth as usual, and a bronze gouge 3°2 inches long, and °75 inch in diameter at the end intended for the reception of the haft. There can be little or no doubt that it lay on the Stalagmitic Floor before Mr. MacEnery entered the Cave, and that he failed to observe it. The only objeet found in the Granular Stalagmitic Floor (that overlying the Cave-earth) was a fine os innominatum of a rhinoceros, No. 5743. In the intact Cave-earth about 1000 teeth of various kinds of mammals were met with, and in the ratios shown in the following Table :— Tastr ITV.—Showing how many per cent. of the teeth found in Cave-earth in the Cave of Rodentia belonged to the different kinds of Mammals. ELODIE via, «loin oy 2ere cote 44 percent, | Reindeer ........ 1:5 per cent. PLOTS CH ogy oy ane iad avers 28 - Elephant ........ 1 8 Rhinoceros ...... 9-5 Hi Whi one teen 1 i Megaceros ...... 4 es Sheepihizs.t2e fs 5 fe WOR): 4:5 foals al 4 > Boras Warbst 1 tooth only. eariisis itil auld . 3 3 Wolfs? oss inn 1 tooth only. Mice rsy! Ste ak Wats 2 In certain parts of the Cave the Cave-earth was found intact in every Level; in others the uppermost Foot-level only had been broken up, leaving the second, third, and fourth undisturbed ; whilst in a third area the two lower Levels alone had not been touched. The second group occupied an area of but limited extent, and needs no further notice, but the distribution of the teeth in the first and third are shown in the following Tables :— 36 REPORT—1872. Taste V.—Showing the distribution of the Teeth of the different kinds of Mammals in each of the four Foot-levels earth in the Cave of Rodentia. of thirteen Parallels of Cave- o|3 4 H za |e ollie é al ls hi} OO Qo eal cecal eel ere 3/ a, BIElS|EPIEl SIS 18/4/88 = om o PIRI SA laa lalo lala No. of Parallels containing teeth in Ist Level] 3) 3) 2) 2|} 2/0|0)| 0)1/0/0 4 Pi _ ma , | 8 9] 5/0| 5/1/1] 40/1] 1 a < : 3ra._ | 11) 9] 5) 2] 1/211] 3/ololo : a 4 4th » | 2 5| 3/1] 1/1}/0] 1/1 }o0}0 " 4 » all Levels| 13}11] 8/5 | 7) 3/2] 6] 2/1/12 Total No. of teeth in Ist Level ............ 13} 7| 3) 2) 2}0/0) 0); 2]}0)0 , { palaBad “ake tier cc} 44\96| 7/0/10/1/1] 6/0}/111 53 5, 3rd ss, 38] 24} 6; 2] 1/3)}1)] 8}0);0);0 ‘ DNA OE PEE Oe 617; 4/1] 1/1]0] 2l1]/o0]}0 : Wiehe et Tereteos oe 101) 7420] 5 |14/ 5 |2\16/3/1]1' Taste V1I.—Showing the distribution of the Teeth of the different kinds of Mammals in the third and fourth Foot-levels of fourteen Parallels of Cave-earth in the Cave of Rodentia. S| 2 2. é/¢/8)8 g E/ElEB/3 218i ale Bia iaisielalalolsa No. of Parallels containing teeth in 3rd Level ....)13/11! 9} 5) 1/)1)1)4/2 r ¥ ‘ th gy os nce JD | ln’ a (Oso leipebeaalea : A ; Fath Teele, ..|14/13110| Biot eal aera Total No. OF Teeth in Bid DLevdlo).4 2b yoo 64(39/isii1}1f1alal7l3s i A OE: ee ae 68/25| 7} 2}0|/0/0/211 . ; Bit deeMtevdin, 12 0, Se 132]64/25/13/1 11/1. 9/4 In the material which Mr. MacEnery had excavated, examined, and thrown aside in this Cave, about 130 teeth were found, which may be apportioned as in the following Table :— Taste VII.—Showing how many per cent. of the Teeth found in the dis- turbed material in the Cave of Rodentia belonged to the different kinds of Mammals. PEVOTIR. ns sp ee iE OCHE ROX Se. eee wa sass 3 per cent. Horse ©.) 2, BES 31 . 1,2 OY Fe peieraeer tan 3 5 Meer’ Ay Saas 12:5 Oi Reindeer.......... 1 tooth. Rhinoceros ...... 8 +s Wolo. fe. ae ee ear je.) Sei Fe 3 i WO ee ee ee d bagi: It has already been mentioned that there were two recesses in this Cave into which Mr. MacEnery did not enter. One, in the north-east corner, ON KENT’S CAVERN, DEVONSHIRE. 37 measuring 4 feet long by 4 feet broad, yielded 36 teeth of hyzna, 5 of deer, 4 of horse, 4 of rhinoceros, 2 of ox, a portion of an elephant’s tusk, numerous bones, and 1 flint flake. The other, in the opposite corner of the Cave, measured 9 feet by 8 feet, and was found to contain 161 teeth of hyena (many of them in parts of jaws, all having lost their condyles), 107 of horse, 40 of rhinoceros, 16 of deer, 10 of bear, 8 of megaceros (of which 5 were in part of a lower jaw), 5 of elephant, 5 of ox, 5 of sheep, 4 of lion, 1 of fox, a great number of bones, balls of coprolite, 1 flake of flint and 2 of chert. The following are among the noteworthy specimens found in the Cave of Rodentia :— Part of the left upper jaw of a bear (No. 5740), containing the last three molars, which are not much worn. This specimen is in a good state of pre- servation, and was found November 18, 1871, in the third Level of Cave- earth, with 2 teeth of hyena, 1 of lion, and 1 of elephant. Part of the right upper jaw of a bear (No. 5745), containing the last three molars, which are somewhat worn. This specimen, which is not well pre- served, was lying with a portion of probably the same head in a corresponding condition, and containing 1 canine of great size. They were found November 20, 1871, in the second Level of Cave-earth, with 1 tooth of hyzena. A canine of a bear (No. 5749), much worn, and having a fang 5:1 inches in girth. It was found November 22, 1871, in the second Level of Cave-earth, with 1 tooth of horse. : Portion of an elephant’s tusk (No. 5764), measuring 10 inches long and 6°5 inches in girth—the largest specimen of the kind the Committee have met with in the Cavern. It is partially invested with stalagmite, to which a few small angular stones adhere, and on its surface there are teeth-marks of hyena. It was found November 27, 1871, in the first Level of Cave-earth, with 2 teeth of hyzena, and gnawed fragments of bone. A very small tooth of an elephant (No. 5774) with two diverging fangs. It was found December 2, 1871, in the fourth Level of Cave-earth. On account of its very small size and unusual fang it was forwarded to Mr. Busk, who has furnished the following remarks on it:—“=2,,, milk-molar of Hlephas primigenius. As this tooth is only one half the size of the tooth usually, but erroneously, regarded as the m.-m. 1, I consider that it represents the very rare occurrence of a true m.-m. 1. If not, it is the smallest tooth of the kind I am acquainted with, except in the Maltese dwarf elephants (vide my paper in Zool. Trans. vol. vi. pl. 53. fig. 2). The proper dimensions of m.-m. 2 in Elephas primigenius are about ‘8 inch x ‘7 inch, and the smallest T have seen of El. indicus is 6 x-48; whilst a tooth in the Zebbug collection is -4 x32, and the present one -45 x ‘3, or nearly the same. One objection, however, and that a strong one, to the present tooth being really m.-m. 1, arises from its having two divergent fangs, while the Zebbug tooth has only one, or two connate into one. This is a very curious specimen, and, as re- gards the elephant, of remarkable interest.”—(Signed) GrorcE Busk. Several good specimens of coprolite were met with both in the Cave of Rodentia and the Wolf’s Cave. Five implements and flakes of flint and chert were found in the former Cave, but none of them rank amongst the best of the Cavern series ; indeed one only (No. 5741) requires special description. It is a light grey flint, rudely oval in form, irregularly convex on both faces, 2°8 inches long, 2°4 inches broad, and ‘95 inch in greatest thickness. Though it has undergone a considerable amount of chipping, and is reduced to an edge all round, it is by no means a well-finished, but was probably a very efficient, “ scraper.” a 38 REPORT—1872. It was found November 18, 1871, with 5 teeth of hyzna, 2 of megaceros, 1 of horse, and 1 of rhinoceros, in the third Level of Cave-earth. Besides the implements, there is a piece of chert having the form of a rude triangular pyramid, 3-2 inches high, its scalene base being 3°3 inches long and 1:2 inch broad. It was found November 30, 1871, with 2 tecth of hyzena, 3 of horse, and 1 of ox, in the third Level of Cave-carth. Its form is scarcely indicative of an artificial origin ; and though its edges are some- what rounded, it does not seem possible for it to have been transported by natural agency from the nearest locality in which such material is now found _ in situ, without being much more rounded than it is. Before proceeding to another branch of the Cavern, the Committee would remark that they commenced their investigation of the Wolf’s Cave on July 12, 1871, and from that time until they had reached its termination, as well as that of its offshoot, the Cave of Rodentia (a period of nearly six months), they cherished the hope that, like Mr. MacEnery, they might find some remains of Machairodus latidens. During their progress they were daily face to face with their energetic predecessor’s labours, and from time to time met with the tools with which they were performed *; but they had finally to leave the two Caves on December 30, 1871, with a feeling of great disappointment that neither amongst-the many hundreds of specimens which Mr. MacEnery had left in his broken ground, nor in the Cave-earth remaining intact beside and beneath his diggings, had they met with any trace of the great object and hope of their search. MacEnery states that he found the famous canines “‘in diluvial mud mixed with teeth and gnawed bones of rhinoceros, elephant, horse, ox, elk, and deer, with teeth and bones of hyenas, bears, wolves, foxes, &c.” +, and that he subsequently discovered an incisor of the same species in the same bed}. It will be seen from Table III., given above, that, with scarcely any other exception than that of Machairodus, such an assemblage of remains as he enumerates was actually found by the Committee in the very soil which he had examined and cast aside; and from Table I., that of the animals in his list, just quoted, the great sabre-toothed Felis was the only one which failed to present itself when the Committee broke up the undisturbed Cave-earth lying below that which yielded the canines and incisor. When to this it is added that the most careful search by the Committee failed to detect in the Cave-earth which they excavated any remnant of the older Cavern deposit, and that MacEnery was struck with the fact that, though “ delicately edged,” the canines were found quite uninjured in the midst of the shattered bones &, a strong case seems to be made out in favour of the propositions that Machair- odus belonged to the Devonshire Cave-earth fauna, and that his remains found in Kent’s Cavern were not redeposited fossils. The Charcoal Cave.—Two passages open out of the south-west corner of the Sloping Chamber, opposite the entrance of the Wolf's Cave. The more important is of considerable length, and leads in a south-westerly direction to a series of large chambers, in which the Committee have not yet under- taken any researches. Mr. MacEnery designated this the “‘ Long Arcade.” Very near its mouth is the entrance of the second passage, to which, for a * The tools were two hammers, a small chisel, a trowel, and an iron scraper. It cannot be necessary to state that these mementos of him who first made the Cavern famous haye been carefully preserved. + See “Plate F,” ‘Cavern Researches,’ edited by E. Vivian, Esq., 1859. t See Trans. Devon. Assoc. vol. iii. p. 370. § Ibid. p. 294. * ON KENT’S CAVERN, DEVONSHIRE. 39 reason which will shortly appear, the Superintendents have given the name of the “Charcoal Cave.” This passage the Committee proceeded to explore before undertaking the Arcade. It extends on the whole in a southerly direction for a distance of upwards of 50 feet, varying from 5 to 13 feet in breadth, and throughout the first half of its length maintaining a tolerably uniform height of from 9 to 10 feet. At 16 feet from the entrance it sends off a branch in an easterly direction, and at 26 feet a second branch towards the south-west; re- solving itself, in short, into three passages, which ultimately reunite, and may conveniently be termed the “ Northern,” “Central,” and “Southern ” branches. They have all, but especially the northern, the aspect of long- continued watercourses fretted by the subsequent and unequal action of acidulated water. Mouths of “flues” present themselves in the roofs and walls ; but none of them have any traces of earthy matter, and few are lined with stalactite. The branches are subject to a very copious drip very soon after rains, but no portion of it enters through the flues just mentioned. At 18 feet from the entrance of the Cave a thin layer of black matter, among which charcoal was conspicuous, was observed lying on the surface of the Stalagmitic Floor, where it covered an area of about 2 square feet. It was thought to be probably the remains of a fire kindled by some recent visitors to the Cavern, though the place seemed an unlikely one for such a purpose, the roof being no more than 4 feet above the floor before the exca- vation, and the narrow passage being very seldom entered by visitors. The whole of the material was carefully collected, and, on being washed and examined, yielded the following assemblage of objects :—Small rough pieces of stalagmitic matter; bits of charcoal, some of them incorporated in the stalagmitic matter just mentioned ; upwards of a dozen small pieces of very coarse friable pottery, of a reddish colour, without any trace of ornamenta- tion, and in all probability parts of one and the same vessel; two unworn lower ‘‘ wisdom teeth” of a human subject; a few entire phalangeal bones, apparently of an individual barely mature ; part of an ulna, of a pelvis, of a vertebra, of ribs, and numerous small fragments of bone; an almost perfect left lower jaw of a fox, containing the canine tooth and five molars; a few incisors and bones of small rodents. In accordance with the practice invariably followed since the commence- ment of the exploration, the water in which the objects just mentioned were washed was passed through a fine sieve for the purpose of detecting minute objects of interest. This water was almost black from the fine matter held in suspension, and which, on being deposited and dried, proved to be fine silt coloured with charcoal. As earlier explorers of the Cavern had in one place in this Cave attempted to break through the Stalagmitic Floor at a point further in than the spot occupied by the black material, and must have frequently trampled on it, there is no difficulty in accounting for the broken condition of the pottery, the charcoal, and most of the bones. It is scarcely necessary to observe that the Charcoal Cave takes its name from the patch of black matter just described. Mr. Charles Rodway, a distinguished dentist of Torquay, to whom the human teeth mentioned above were submitted, was so good as to furnish the following note respecting them :— “Torquay, June 11, 1872. “My pear Srr,—I have examined the two teeth you brought me, and they are right and left inferior ‘ dentes scpientie’ of a human being. They . 40 REPORT—1872. are the teeth of a subject between the age of 15 and 20 years, judging from the undeveloped state of the roots, which later in life would be longer, with the pulp-cavity at the apices considerably smaller. I notice upon the lingual surface of the left tooth what I take to be a deposit of salivary calculus, which leads me to suppose that they were already erupted from the gum, although not sufficiently risen to have been used in mastication, as the enamel on the masticating-surface does not appear to have been subjected to friction. It would be impossible to say whether they are the teeth of a male or female; but from their strong likeness they are unquestionably the teeth of the same person. «Yours truly, (Signed) *‘ Cuartes Ropway, 8.D., Li. R.C.S.” With the exception of the jaw of a fox, and the incisors and bones of rodents, all the osseous remains were believed by the Superintendents of the Exploration to be those of a human subject of about the age indicated by the wisdom teeth, and were all forwarded to Mr. G. Busk, who has furnished the following Report on them, confirming, with a few exceptions, their human character. The specimens were twenty in all, and were numbered ;2_, sr and so on, Mr, Busk’s Report. “No. =. Fragment of left lium; probably female ; age unascertainable. “2. Not human. «3. The sternal end of a human clavicle, “4, First phalanx of third finger, right hand; entire, but with the epiphysial line of junction quite distinct ; age 18 to 20. “5. Portion of body of lumbar vertebra, showing that the epiphyses were ununited ; age the same. «6, A fragment of the sacrum. “7, First phalanx of fourth finger, right hand, with the epiphyses detached. “8. Second phalanx of right thumb. “9. Upper end of right ulna, of rather peculiar form; the peculiarity con- sisting in the straightness of the posterior angle and the breadth of the square anterior face. Epiphyses quite united; but as this union takes place at 16 years, the bone probably belonged to the same individual as the above. “10. Shaft of humerus (?) of (?). Not human. “11. Fragment of second right metacarpal. 12. Distal portion of first metacarpal, or phalanx of thumb. ‘13. Fragment of the shaft of a clavicle, of slender make. “14, Fragment of the left ischium of a young ruminant of the size of the ibex, or a large goat; but may be by chance a young red-deer—not reindeer, nor fallow-deer, nor roebuck. «°15, Right cuneiforme bone. “16. Right pisiform bone. “17. First phalanx of fourth toe. «18. Second phalanx of fifth toe. “19, Third phalanx of third finger. «© 20. Second phalanx of toe. (Signed) “ Grorce Busk.” “32 Harley Street, July 29, 1872.” The Superintendents incline to the opinion that, since the age of the sub- ject to whom Mr. Busk ascribes the bones harmonizes with that of the person ON KENT’S CAVERN, DEVONSHIRE. 41 to whom Mr. Rodway says the teeth belonged, all the remains are portions of the same skeleton, and that they had been preserved in a cinerary urn of which the potsherds found with them were fragments. There was a continuous Stalagmitic Floor from the entrance of the Char- coal Cave to 19 feet within it, except at one place, where it did not quite ex- tend from wall to wall. In the next 5 feet the Cave-earth was without any covering, but at 25 feet from the entrance a floor again presented itself. It was of the usual character, varied from 2 to 12 inches thick, and near the entrance there was in it, about 2 inches below the surface, a thin layer of carbonaceous matter. In the northern branch the floor was everywhere continuous, and varied from 18 inches thick at the entrance to 1 inch at the inner end. In the central branch the floor was but partial, never exceeded 9 inches thick, and was occasionally no more than a mere film. In one or two instances pieces of Old Crystalline Floor were incorporated in it. There was very little floor in the southern branch. Remnants of an old floor in situ, extending from wall to wall, presented themselves in each of the branches, always at some height above the Cave- earth. They were indications, of course, of the former existence, and at least partial dislodgement, of a deposit older than the Cave-earth, and which there attained a higher level. The most considerable of them was in the central branch: it was from 9 to 10 feet long, 3 inches thick ; its upper surface was 1°5 foot below the limestone roof, and its lower surface 4 feet above the granular Stalagmitic Floor, the spaces between it and the roof above, and the ordinary floor below, being quite unoccupied. The remnants in the other branches differ from this in their measurements only. With exceptions in portions of the central and southern branches, to be noticed immediately, the mechanical deposit in the Charcoal Cave was true Gave-earth. At the entrance, and for about 11 feet within, it contained an unusually great number of fragments of limestone from top to bottom of the section. Beyond the point just specified, up to 18 feet from the entrance, such fragments were rare, except in the uppermost Foot-level, where they still abounded ; their place below being taken by a few pieces of red grit, some of which were fossiliferous, whilst the Cave-earth became very sandy. From the first to the second bifurcation of the Cave, as well as for a few feet within each branch, the Cave-earth was no more than from | to 3:5 feet deep, and rested on a continuous, but very uneven, limestone floor—an instance, and probably the only one yet known in the Cavern, of this floor being reached. In the northern branch the deposit was true Cave-earth throughout. In the central one the Cave-earth contained a few pieces of Old Crystalline Floor, and throughout the innermost 10 feet rested immediately on the old dark red Breccia, found elsewhere in the Cavern beneath the Crystalline Stalagmitic Floor. In the southern branch nothing but true Cave-earth was found from the entrance to 8 feet within it; but beyond that to the end, a distance of 17 feet, from the base of the section to 2°5 and even 3 feet above it, the entire accumulation was the old dark red Breccia, rock-like in its cohesion, continuous from wall to wall, and clearly in situ. It may be well at this point to give a brief recapitulation of the facts as they presented themselves in ascending, but not necessarily chronological, order, in the same vertical section, in the central and southern branches :— First, or Lowest. Dark red rock-like Breccia, at least largely composed of angular, subangular, and rounded fragments of Devonian grit, derivable 1872. z 42 REPORT—1872. from the adjacent loftier hills, but not from the comparatively low one in which the Cavern occurs. Its depth is unknown, as its base has not been reached. : Second. Cave-earth, consisting of a somewhat light red loam and generally about 50 per cent. of angular fragments of limestone, with an occasional pebble not derivable from the Cayern-hill. Its depth was variable, but never less than 1 foot. Third. A floor of granular Stalagmite, from 1 to 18 inches thick. Fourth. An unoccupied space from 1 to 4 feet high. Fifth. A floor of Crystalline Stalagmite from 3 to 4 inches thick. Sixth. An unoccupied space from 1 to 3:5 feet high. Seventh. The limestone roof of the Cave. Were we to speculate on the history of the Charcoal Cave as indicated in the facts just described, we should find ourselves taken back to the time when it was formed, not by any conyulsion, but by the actual and probably gradual removal of the limestone which once filled the entire space between the walls, as is shown by the unfissured roof and the continuous limestone floor. Secondly, so far as can be ascertained, the introduction of angular, sub- angular, and rounded pebbles of dark red grit, with sandy mud derived from their attrition, until the Cave and its branches were filled almost to the roof. Thirdly, the introduction of materials from without having ceased, the Breccia which had accumulated was hermetically sealed up with a cake of Crystalline Stalagmite, from 3 to 4 inches thick—the result of the slow solu- tion and precipitation of calcareous matter. Fourthly, the Crystalline Stalagmite was partially broken up, and a portion of the Breccia was dislodged, the removal being more complete in some parts than in others. Fifthly, again there was introduced a mechanical deposit, but instead of dark red grit and sandy mud, it consisted of a light red loam and angular fragments of limestone of various sizes. It did not attain to so great a height as the previous deposit of dark red material. Sixthly, a floor of Stalagmite, differing from the former in being granular instead of crystalline, was formed on the red loam or Cave-earth, at a lower level than that which sealed up the Breccia. Seventhly and lastly, this latter floor being completed, there was placed on it a small cinerary urn, containing human bones and bits of charcoal. But to return. The deposits in the Charcoal Cave were by no means rich in osseous remains. The granular stalagmite yielded a few unimportant bones only, and in the Cave-earth there was but a comparatively small number of bones, and no more than 85 teeth. The latter belonged to different kinds of mammals in the ratios shown in the following Table :— Taste VIII.—Showing how many per cent. of the Teeth found in Cave-earth in the Charcoal Cave belonged to the different kinds of Mammals. HiGrse:t kane todd Sore Ret jeDOT, COM | BOAT so. wt ons aloes ig 3:5 per cent. Hiryeaniate 2. so setors Fees 29-5 hy Ao) ae eee ae 2:5 a OX. ANe tara Sonar 12 a Hlephant,........ 1 < Rhinoceros ...... 10°5 55 D2 ea 1 fa QadSeriss awe cece 6 - SMECD: feycrene «55 e¥icgs 1 = There were but thirteen of the Parallels consisting of Cave-earth from top tu bottom of the 4-feet sections which contained teeth, and, these amounted to no more than 31 in number. Their distribution is shown in the following Table :— ON KENT’S CAVERN, DEVONSHIRE. 43 Tanrn [X.—Showing the distribution of the Teeth of the different kinds of Mammals in each of the four Foot-levels of thirteen Parallels of Cave- earth in the Charcoal Cave. some ¢i@/8/]./3 ig B/RIS/8 | ela 2 Hib le#liala lola No. of Parallels containing teeth in 1st Level ....| 4 2 1 1 0; O 1 ” ” ” 2n ” 2 2 0 0 0 0 0 % eS te 3rd, Pe) B4) Ocho he hto4e'O ” ” ” 4th ” 2 2 1 0 0 1 0 bs :; . “5p 925 Wy i Vc ih eke tig MND Tedbof teeth Ieiee Bevel vse. 4. 004.vio.. 7| 2| 11 1] of o| 1 - se bn RAI: RASS kG atte 4| 2| 0] 0o| o| o| 0 x i Goct Sn Plies ae SIR RIaR aS SS Oe Oi deta 0. Lad . . Ree ee oi oo tl Oe Ulett Une a 2 witha 2.2) sobais, egy, 160) y oy! ow omelet aw The following may be mentioned amongst noteworthy bones found in the Charcoal Cave :—The distal end of a tibia (No. 5906), an astragalus, and the proximal end of an os calcis of horse, all inosculated in true anatomical posi- tion as when clothed with flesh, thus intimating that they were so clothed when lodged where they were found. The fractured end of the tibia affords decided evidence of the powerful jaws of the hyena. With the specimens were found another distal end of a tibia of horse, a metatarsus of horse, a metatarsus of reindeer, part of an antler, a rather small astragalus, and a gnawed bone. They were lying but little below the surface of the Cave-earth, where it was not more than 1-5 foot deep, almost in contact with the roof of the southern branch, and deposited on the old dark red Breccia; and they were extracted June 6, 1872, in the presence of one of the Superintendents. In a precisely similar situation, and but one foot from the objects just named, a metacarpus of horse and a large atlas were found two days after. On April 22, 1872, there were found on the surface of the Cave-earth upwards of 600 bones of rodents all lying together; and on the 11th of the same month nearly 800 small stalagmitic bodies, which may be likened to rather large, ill-shapen, rugose marbles, were found in a heap on the Cave- earth, im a small recess in the wall of the southern branch, with two hazel- nut-shells and a piece of bone. On May 17 a similar but smaller heap, con- taining about 100 such “marbles,” with a toothless fragment of jaw, was met with in a position precisely like the former. Several coprolites were found in the Charcoal Cave. One small flake of white flint (No. 5899) was found in the southern branch on May 22,1872. It may be dismissed with the remark that it lay in the first Level of Cave-earth with 2 teeth of hyena. Bones and teeth were found in the old dark red Breccia in the central and southern branches. The bones were much broken in digging them out, on ac- count of the rock-like character of the Breccia. The teeth, like those found in the same deposit in other parts of the Cavern, were all of them those of bear. In their Fifth Report (Exeter, 1869) the Committee called attention to a flake of flint found in the Breccia in the “ Water Gallery,” and pronounced by Mr. John Evans, F.R.S., 2 Member of the Committee, to be not only of E2 4A, REPORT—1872. artificial origin, but to have been used by man*; and they ventured on the opinion that, from its being coeval with the Breccia (which must have been laid down long before the deposit in which, so far as the Cavern evidence goes, the first traces of the Cave-hyena, Cave-lion, mammoth, and their con- temporaries were met with), it was anthropologically by far the most impor- tant object the Cavern had yielded. From that time the Committee have had no opportunity of investigating this old Breccia, and hence no announcement of further discoveries of the kind were looked for in their Sixth or Seventh Reports (1870 and 1871). They are now, however, enabled to return to the subject, and to state that the Breccia has yielded two additional flint implements. The first of these (No. 5900) was found May 22, 1872, in the southern branch, from 1 to 2 feet deep in the Breccia, in which it was firmly im- bedded ; and over this was an accumulation of typical Cave-earth, having no Stalagmitic Floor either above or below it. There were no bones found near the implement; but vertically above it, in the Cave-earth, were the small flake of white flint and the 2 teeth of hysena just mentioned. . It is rude in form, rather over 5 inches in greatest length, scarcely 3 inches wide, and about 1-5 inch in greatest thickness. It exhibits a small portion of the sur- face of the nodule from which it was made, is of a dull cream colour, and its weight is less than that of ordinary flints of the same size ; in these respects resembling some of the tools found in the Windmill-Hill Cavern at Brixham. All the dimensions of the second implement (No. 5903) slightly exceed those of that just described. Its colour is a pinkish cream; one of its surfaces is nearly flat, whilst the other is very convex, and retains much of the sur- face of the original nodule. One of the Superintendents, who assisted to extract it, had the opportunity of studying it before any attempt was made to move it. The Breccia was compactly cemented together, and the imple- ment was firmly imbedded in it, at 1 foot below its surface, above which was Cave-earth to the depth of 27 inches, and, without being covered with sta- lagmite, reaching within 3 inches of the roof; in other words, the united thickness of the two deposits overlying the tool was 39 inches. It was di- stinctly observed to be fractured ; and as the severed portions were in such close contact as to render the line of junction almost microscopic, it had obvi- ously been broken where it lay. Every care was taken in its removal ; but on being extracted it fell into three pieces, one of which remained firmly attached to and incorporated in a lump of the Breccia. The fractured surfaces showed that its colour was whitish throughout, and that its texture was granular. It was found May 27, 1872, in the southern branch of the Cave, about 2 feet from the specimen just described (No. 5900), and, like that, had no bones near it. The excavation of the Charcoal Cave and its branches was completed July 7, 1872, the labour of 4:5 months having been expended on it. The Long Arcade.—The principal passage opening out of the south-west corner of the Sloping Chamber, as already mentioned, was termed the Long Arcade by Mr. MacEnery +, and the ‘‘ Hyeena Cloaca Maxima” by Dr. Buck- landt. It has a direction towards south-west, and is the great thoroughfare to the “ Labyrinth,” ‘“ Bear’s Den,” and ‘‘ Cave of Inscriptions.” Its explora- tion is at present in progress. Up to the end of July about ten weeks’ work had been expended on it; but a very large amount remains to be done there. Mr. MacEnery had commenced the exploration of the Arcade, but meeting with fewer fossils than he hoped, soon abandoned it §. * See Report Brit. Assoc. 1869, pp. 202, 203. t See Trans. Devon. Assoc. vol. iii. p. 303 (1869). { Ibid. p. 237. § Ibid. p. 290. ON KENT’S CAVERN, DEVONSHIRE. 45 At its entrance this branch of the Cavern is about 17 feet in width and 13 in height. The roof is the naked limestone, much fretted or honeycombed. The Granular Stalagmitic Floor was continuous in every direction and of very great thickness. Its surface, for some distance, was occupied by a series of natural basins, bounded by stalagmitic walls rising above the general level of the floor. They varied in depth from an inch to fully a foot, and in wet seasons were constantly full of water. Similar basins occur in other parts of the Cavern, but those at the mouth of the Arcade (the great thoroughfare) have attracted a large amount of attention. Mr. MacEnery described them as “encircled with wavy walls, rivalling the most exquisite works in pastry” *. When breaking up the floor it was observed that the bottoms of the basins were formed of a softer looser stalagmite than that composing the walls, and that these dissimilar characters extended vertically downwards through the entire ‘‘ Floor.” Charcoal has been found in a few of them, and one con- tained two or three bones. At the western wall of the Arcade, and several feet from it, the Stalagmitic Floor was never less than 4, and not unfrequently upwards of 5 feet thick ; but at the eastern wall it rarely measured more than 2 feet. The upper- most 6 inches were frequently of a dirty reddish colour, as if soil-stained ; but at greater depths it was very pure, often granular, occasionally flaky, and everywhere distinctly laminated. At something more than a foot from the bottom of the Floor, there was found in every section a roughly horizontal, continuous, black line, extending from the western wall of the Arcade to a distance, in one instance, of 7 feet, generally about a quarter of an inch thick, but never exceeding half an inch. It was due to the presence of charcoal, and, of course, represented a thin sheet of that material. It was very carefully watched as the Floor was broken up, but yielded no trace of bone or of any substance besides the charred wood. This “‘ Charcoal Streak” was observed and studied by Mr. MacEnery, who, attaching great chronological importance to it, described it no less than four times +. The portion of the Floor in which he found it was not more, at most, than half the thickness of that recently broken up by the Committee. From his description it appears to have been horizontal, midway from the surface to the bottom of the stalagmite, from 1 to 2 inches thick, about 5 feet in greatest length in any section, composed of charred wood and straw, and to have contained the following objects imbedded in it :—Small polished pebbles of white flint, shells, two portions of the jaw, a tusk, and some phalanges of boar, the under jaw of a badger, bones of rabbits and rats, and cylindrical bones which Dr. Buckland, who extracted them, assigned to deer. The latter were half-roasted, and, with the exception of the jaws of the boar, all the bones had been more or less exposed to the action of fire. No extraneous objects of any kind were found in the Floor above or below the “ Charcoal Streak.” The Committee have been more fortunate, having met with bones in other parts of the stalagmite, but all of them below the black line. The most note- worthy of these are a tooth of deer (No. 5818), a large vertebra (No. 5951), and a well-worn tooth of hyena (No. 5969). In the same deposit a piece of black flint (No. 5938) was found July 18, 1872. Mr. MacEnery’s diggings in the Cave-earth at the entrance of the Arcade had in some places been carried to a depth of 3 feet below the Stalagmitic Floor, thus leaving the fourth Foot-level intact. They gradually became less and less deep, until at 12 feet from the entrance they ceased entirely. This excavated material has been carefully reexamined, but contained very few specimens. * Trans. Devon. Assoc. vol. ili, p. 236. t Ibid. pp. 235, 236, 261, 291, and 335. 46 REPORT—1872. The deposit underlying the Stalagmitic Floor was typical Cave-earth, having no peculiar characteristics. Up to the end of July no trace of the Breccia (the older deposit) had presented itself, either am situ or in incorpo- rated fragments. It has not proved to be very rich, nor has it been remark- ably poor, in bones and teeth; and it has yielded two flint implements. It is believed, however, that the lack of abundance will be found to be fully compensated by the character and value of at least one of the specimens. One of the implements (No. 5819) is a somewhat mottled white flint, rather irregular in form, flat on one face, doubly carinated on the other, 3-3 inches long, 1:1 inch in greatest breadth, and -4 inch where thickest. It was found in the first Foot-level of Cave-earth with a portion of a grey flint nodule, apparently fractured artificially. The second implement (No. 5829) is a bluish-grey flint, semilunar in out- line, 2-5 inches long, 1:5 inch broad, and fully °5 inch in greatest thickness. It was found, with a tooth of hyzena and a tooth of horse, in the third Foot- level of Cave-earth. Up to the end of July 120 teeth and a considerable number of bones, be- longing to various kinds of mammals, had been met with. As the exploration of the Arcade is not completed, it is perhaps undesirable at present to exhibit the distribution of the teeth in a tabular form. The hyzena, as usual, takes the lead, and is followed by the horse and the rhinoceros in their usual places, Though, amongst the animal remains, several good specimens have been met with in the branch of the Cavern ‘at present under notice, only two of them require special mention. One of these (No. 5968) is the right lower jaw of a young bear, and, what is very unusual in the Cavern, perfect i in all its parts. Such, however, was its fragility that it was broken in taking it out of the deposit. It was found July 30, 1872, with an additional canine of a young bear (in all probability belonging to the same individual) and a tooth of elephant, in the third Foot-level of Cave-earth, over which the Stalagmitic Floor was 5 feet thick. The other specimen (No. 5962) is a well- marked incisor of Machain odus latidens, found July 29, 1872, with the left lower jaw of bear containing one molar, in the first or uppermost Foot-level of Cave-earth, having over it the Granular Stalagmitic Floor 2:5 feet thick. It answers admirably to the following description given by MacEnery of the incisor he found :—*‘ The internal face of the enamel is fringed with a serrated border. This tooth is distinguished further by two tubercles or protuberances at the base of the enamel from which the serration springs, and describes a pointed arch on the internal surface. .... The body of the tooth in this specimen is not com- pressed but rounded” *. He adds, “ Whether this belongs to an inferior species of U. cultridens, or [is| simply the incisor anterior to the canine of the larger species of U. cultridens, I am not able to pronounce with certainty. If merely the incisor, it is still interesting, as it serves to show that the serrated character is not confined to the canines, and that the rest of the teeth, and ae the frame, are marked by a peculiar conformation.” A glance at the new specimen suffices to explain why Mr. MacEnery was uncertain respecting the canine or incisive character. Indeed the workmen _ sent it to the Secretary of the Committee under the belief that it was the canine of a wolf, it being partially covered with Cave-earth; and its true character was detected whilst it was being washed, August 5, 1872. MacEnery states that his incisor, which unfortunately cannot be traced, was ‘‘ about an inch long” *—the expression, in all probability, of a rough * Trans. Devon. Assoc. vol. iii. p. 370. ee. FOUNDATION OF ZOOLOGICAL STATIONS. 47 guess, and not of actual measurement. ‘he incisor from the Cavern (doubt- less that discovered and described by MacEnery) figured by Professor Owen in his ‘ History of British Fossil Mammals, &c.’* very nearly corresponds in size with its homologue just found. The new specimen is slightly longer in the crown, and somewhat thicker in the fang. The Committee cannot but feel that their thanks, as well as those of all paleontologists, are due to the Committee of the Geological Section for having, year after year from 1864 inclusive, cordially applied for a grant from the funds of the Association for the exploration of the Cavern, to the Committee of Recommendations for having recommended the successive applications, and to the General Committee for having annually voted the sums applied for. One of the hopes of the Cavern Committee, in commencing their researches, was that they might find some traces of Machairodus. This they have never abandoned, though year after year passed away without success; and they cannot but express their gratitude to the body whose patience and liberality has enabled them to continue their labours until this hope was realized. The greater part of this Report was written before the discovery was made; and had the work ceased on July 28, 1872, those who always declined to believe that Machairodus had ever been found in Kent’s Cavern, would have been enabled to urge, as an additional argument, the fact that the consecutive, systematic, and careful daily labours of 7 years and 4 months had failed to show that their scepticism was unreasonable. This great accumulation of negative evidence has been for ever set aside, and-all doubt of Mr. MacEnery’s accuracy for ever removed, by the discovery the Committee have now had the pleasure to announce. They can now announce also that Machairodus latidens and man were con- temporaries in Britain ; for even if, notwithstanding the great array of facts to the contrary, the former should prove to have belonged to the era of the Breccia, and not to that later time represented by the Cave-earth, the two flint implements found in the Breccia, to which attention was called in a previous part of this Report, as well as that produced and described at Exeter in 1869, take man back to that earlier period also. Report of the Committee appointed for the purpose of promoting the Foundation of Zoological Stations in different parts of the World. Tur Committee beg leave to report that, as stated in the Report of last year, the Zoological Station of Naples will be ready and in working order in the beginning of January 1873, the progress of the construction being such as to enable Dr. Dohrn to make this assertion. This undertaking has received much official and private assistance, not only from public authorities, but in a very high degree from private persons. The Committee have much pleasure in acknowledging especially the extraordinary services rendered by Mr. W. A. Lloyd, of the Crystal-Palace Aquarium, in giving every assistance to Dr. Dohrn, as far as technical difficulties are concerned. Special care has been taken to secure donations to the future library of the Station. The eminent firm of Engelmann, in Leipzig, has presented all its works on Biology not previously possessed by Dr. Dohrn. Vieweg, in Brunswick, has also sent all his publications on Biology. Theodore Fischer, in Cassel, has done * A History of British Fossil Mammals and Birds. By Richard Owen, F.R.S., F.G.8., (1846), p. 182, fig. 70. 48 REPORT— 1872. the same. Important donations are promised from Dr. Alexander Agassiz, Cam- bridge, Mass., comprehending the publications of both his father and himself. To secure the development of the library on a greater scale, it will be necessary to make general applications. For this purpose, Dr. Dohrn, assisted by several of the greatest German publishing firms, is preparing an appeal to all German publishers, and hopes also to succeed with a like demand in Italy. The Committee hope that the British Association will lend its moral assistance to a similar demand in this country, not only by granting a complete set of its own publications, but by recommending a similar act to other scientific bodies and private persons. The Committee are further glad to announce that some Steam Navigation Companies are prepared to grant a free passage to the Naturalists, and free transport for the goods sent to or from the Zoological Station. Dr. Dohrn contemplates a new step for the purpose of securing a larger income for the Naples Station. He is about to offer to several Governments, Universities, and Scientific Bodies working-tables in the Laboratory of the Station for a certain annual sum. The payment of this sum would confer upon the subscribing Government, University, or Society the right of appoint- ing naturalists, who, on presenting a certificate to the administration of the Station, would be furnished with a working-table and admitted to a partici- pation in all the other very extensive advantages of the Station. The Committee think it well earnestly to advocate this new step of the administration of the Naples Station, the more so as it lessens the burden of the single naturalist, enabling even such as are destitute of means to profit by the manifold advantages of the Station, while it guarantees a fixed annual income to the latter, which would be employed in improving the technical and other means of investigation. Fourth Report on the Fauna of South Devon. By C.Srence Bartz, F.R.S. In presenting to this Association the Fourth Report of the Marine Fauna of the South Coast of Devon and Cornwall, it cannot he supposed that any great increase of novelties, either in species or genera, can be added to the forms known; and to recapitulate those already reported is unnecessary. My attention therefore has been directed more especially towards the develop- ment and habits of animals that have fallen within my range of observation. Facility has been given in this direction by the establishment at Plymouth, under my suggestion and plan, of a marine pond for the purpose of keeping and storing animals for the aquarium at the Crystal Palace. Already it has given us opportunities of observing the habits of animals that could scarcely be obtained under any less favourable circumstances. These oppor- tunities will become still more numerous and valuable as the conditions of the pond become more adapted to deep-sea species. The pond is formed out of a deep gully in the limestone shore, and much of it extends far into a cave beneath the cliff. The pond is irregular in shape and depth, and affords many crannies, nooks, and corners for animals to live or take refuge in. At the entrance, where the water is deepest, the width of the pond is about eleven feet, but at other places it is more than double that extent ; and when the sea rises to the higher spring-tides the length of the pond extends upwards of eighty feet from the wall that separates it from the waters of the Sound. The rocks, which were formerly covered with ON THE FAUNA OF SOUTH DEVON. 49 Fucus, are now matted with grass-green Algz ; and with the change the water has lost its foul and stagnant appearance, and become pellucid and clean. The following fish have been taken on the coast since the last Report, and with those already mentioned form a tolerably perfect list of the fish of the southern coast of Devon and Cornwall :— List of Fishes taken off Plymouth. (The English names are from Couch.) Raia marginata (Bordered Ray) EMMMRENONB Re eeteesssecscesscccsescaatsessoctcssaassaceeaee Squatina congelus (Monk-fish) Syngnathus (several species) Anguilla conger (Conger) Lepidogaster cornubiensis (Cornish Sucker) etme ewww reese nee n ee eee Frequency. Common. Common. Common Common Common .........+ Not common; com- mon in some parts. Lepidogaster bimaculatus (Doubly-spotted Sucker) Not common...,..... Solea vulgaris (Sole)...........0:0csecseceteeeeee eaeeeenes Common ............ Rhombus punctatus, young (Miiller’s Topknot) ...) Common ............ SORES oa arc eine dette a cle sie sip sti e'v'ad vow a euiieinin Abundant ..,......... Motella vulgaris (Three-bearded Rockling) .........| Abundant ............ Merlangus pollachius (Pollack) ..................00000- Abundant ............ Morrhua lusca (Bib, or Whiting Pout).............. Abundant ............ Morrhua minuta (Bower) ............s0cceceeeeeee eens Abundant ............ Morrhua vulgaris (Whiting) .............0ccse:seneeees Common ............ Clupea harengus (Herring).............:sscceeceeeseeees Occasionally ......... Alosa finta (Shad, Maid)...............cseeeeesseeeeeees Occasionally ......... Belone vulgaris (Garfish) ....+......:..eseceeeeeeee ees Common ............ Scomberesox saurus (Skipper) ...........:seseeeeseees Once only ............ Labrus maculatus (Ballan Wrasse) ...........0..008 Abundant ............ Labrus mixtus, g¢ & ? (Cuckoo Wrasse) ..........-. Not common ......... Crinilabrus melops (Corkwing) ................02s0e00 Abundant ............ Crinilabrus rupestris (Goldsinny) ..................... Abundant ............ Acantholabrus exoletus (Rock Cook)..............-.- Abundant ............ Callionymus lyra, § & ? (Yellow Skulpin) { ae ase ak Gobius niger (Rock Goby) ........... Acsconapodnaeneiae Abundant ............ Gobius ruthinsparri (Two-spotted Goby) ............ Abundant ............ Gobius unipunctatus (One-spotted Goby)............ Abundant ............ Blennius montagui (Montagu’s Blenny) ............ Uncommon ......... Blennius gattorugine (Gattorugine) ............ ...| Not plentiful ......... Blennius pholis (Shanny) ............:.cseceseeeeeeeees Abundant ............ Mureenoides guttata............c.ccccceceeeeeeeeeeeeeeeees Abundant ............ Mugil capito (Grey Mullet) ...............c ceeeeeee ee Abundant ............ Atherina presbyter (Smelt) ...,........ccsccsseeeeeseeees Abundant ............ Zeus faber (Doree) .........02.seceeceeeeeeeeseereeceecees Not common ......... Capros aper (Boar-fish) ......s00..sesessecssseeeeeseeees Common ............ Scomber scombrus (Mackerel) .............0..0.:0e00e Common ............ Pagellus centrodontus (Bream) ...............06000008 Common ............ Gasterosteus spinachia (15-spined Stickleback)...... Common ........:... Cottus bubalis (Lucky Proach) ............0.:00:00200 Common ............ Aspidaphorus cataphractus (Armed Bullhead)...... Common ............ Trigla cuculis (Red Gurnard)................eesceeee ee Common .........+.5 Trigla hirundo (Tub-fish) .......sseee.cseceeeeeeeeeeees Common ............ Trigla gurnardus (Grey Gurnard) .................266 Common ............ Maulus surmuletus (Surmullet) ................:00:000+ Not common..,.,..... Trachinus draco (Greater Weever) ..............0+0 Common ............ Trachinus vipera (Viper Weever) ..............sserees Not common ......... Serranus cabrilla (Coruber) ...............0000e00eee Not common......... Labrax lupus (Bass) Common Locality. Sound. Estuaries. Sound. ” Estuaries. ” Sound. ” ” ” . Estuaries. Sound. [Hoe. Under the Sound. ” Estuaries. Sound. ” Estuaries. Sound. ” ” Estuaries. Offing. Sound. ” ” : Estuaries. Offing. Estuaries. ” Offin g. Estuaries. Sound. 50 REPORT—1872. Most of these have been confined in the pond, where they generally appear to acclimatize themselves readily. The exceptions appear to be among those species whose habits are of an erratic character, as the Mackerel (Scomber scombrus). Several specimens of this species have been placed in the pond, where the imprisonment alone seemed to operate prejudicially upon them. They appeared to roam from point to point, seeking an outlet; but finding none, they one after another succumbed to their altered conditions and died. But other fish not only live but thrive well, apparently having no consciousness of any altered circumstances in their existence. ‘These, from a constant and close inspection, will, I hope, furnish us with opportunities of recording notes of their habits and ways that cannot be obtained under less favourable conditions. The beautiful Blue Wrasse (Labrus miatus) has already given us an instance that is important in the history of its life, in the decided preference it exhibits in sexual selection. It was not until it had been observed in confinement that the Blue Wrasse and the Spotted Wrasse were known to be one and the same species. ‘lhe male is very much more rare than the female, and is probably supposed to be more rare than it is, from the fact that those that have been confined in the pond at Plymouth appear to be losing the distinguishing colours and assuming that of the female as the summer time is passing on, so that there is much reason to believe that the beautiful deep- blue colour only exists, or at least is much more intense, during the pairing or breeding time. During this period the male has been seen to select its special favourite out of a considerable number of females congregated in the pond, and faith- fully accompany her as she swam about from place to place. In accordance with this same observation, Mr. Alford Lloyd, of the Crystal-Palace Aquarium, informed me that when at Hamburg he had noticed this peculiarity, and first drew my attention to it. He said that having a very handsome specimen of the Blue Wrasse, he placed him into a tank of water alone: instead of conducting himself like an orderly fish and swimming quietly, he for some time swam eagerly about in search of change; but not finding it, he took the unusual freak of jumping out of the tank; this he did two or three times. Fearing to lose him, it was determined to put another in with him; and a female specimen was selected. This appeared to have no very favourable sue- cess, for the Blue Wrasse most ungallantly chased her about, and tried to drive her from his presence. Another female was selected, with the same result. It was then determined to place the original specimen into a tank in which there were several swimming peacefully about, among which were many un- selected females. Immediately the transfer was made, the animal swam amongst the forlorn group and fixed on one, by no means the handsomest of her sex, and selected her as his mate. With this one he was returned to his own tank; and here he conducted himself in a peaceful manner, never attempting again to jump out of the tank in which he was confined. T have also to record the capture of a specimen of the Bogue (Sparus boops, L.), 113 inches long; when it was brought to me it was in a very beautiful state of preservation. Of this species there have been but two or three speci- mens taken, and these scarcely so fine as the specimen now recorded. It was taken in a trawling-net, and brought in alive, but did not survive its capture. The specimen is preserved in the collection of the Museum of the Plymouth Institution. Mr. Brooking Rowe informs me that in July last a specimen of the German or Long-finned Tunny (Orcynus alalonya) was taken in the Laira estuary, ON THE FAUNA OF SOUTH DEVON. 5] near Plymouth. It was 9 feet long; the tail, from tip to tip, was 2 feet 11 inches wide; the girth 5 feet 11 inches: it weighed 800 lbs. This is, I believe, only the fourth example mentioned as haying occurred in Great Britain. On the 6th of September last I had brought to me a small fish (living) about three quarters of an inch long, of a purple-black colour, with the exception of the caudal, posterior dorsal, and postanal fins; these were so transparent as not to be visible without extreme care while the animal was in the water. The head was large, with the upper jaw slightly protruding over the lower. The head was elevated between the eyes, and three sharp spines were present on the postero-lateral margin, just above the gill-covers ; a row of small spines were visible on each side of the posterior half of the body, and three large spines are implanted at the lower base of each lateral fin ; but the most striking peculiarity of the animal exists in the large size of the fins themselves, particularly the laterals. There are four, two upon each side; they are narrow at the base, where they are connected with the animal, from which point they gradually, but rapidly, increase in width and length, until the latter is about one third of the length of the animal, and the former more than equal to its depth. An examination of its details with that of known species has led me to the conclusion that it is a young specimen of the Grey Gurnard (Trigla gurnardus). CRUSTACEA, Among the Crustacea I have as yet but little to report, some observations on the earlier development of the Homarus having been interfered with by the loss or robbery of some specimens that I had retained in special crab- pots some fathoms under water. This has deferred the opportunity until another season. There are, however, two subjects of interest that might be here alluded to. The first is the decrease that is perceptible in the numbers of the edible species of Crustacea. This is the more apparent in the littoral than in the deep-sea forms, and is likely to be more felt with the rapidly increasing prices of articles of consumption. The circumstance no doubt arises from the custom of destroying the females as well as the males at all seasons of the year, and of the preference given for culinary purposes to the female lobster (Homarus marinus) when heavy with spawn. The increased value of the animal makes it eagerly sought after by fishermen. But there is not even this excuse for the capture of the female crab (Cancer pagurus). The marketable value, as compared with the male, is at least one fifth ; this arises from the smaller size of the animal as a whole, and of their claws in particular. But they are captured in greater numbers, and are con- sequently wantonly destroyed, being frequently hawked about the streets for a very few pence apiece. It appears to me that there could scarcely be any hardship inflicted, even temporarily, upon “ shell-fishermen ” if they were in- terdicted from taking the female lobster during the spawning-season, that is, from February until May, and that of the common crab at all. I am aware that this suggestion is open to the remark that the lobster and the crab are so prolific that the number of ova that each hatch in a season is in the former several hundred thousand, and in the latter more than a million at a time, and that these very large numbers would within a short period soon stock all the bays of our coast. To this I would reply, that in all those forms of life where the ova are most abundant, the development of 52 REPORT—1872. that species is least in proportional quantity. This is true of crustacean life as well as that of other forms; and I think it worthy of consideration, particularly by those who, as a crucial test in the theory of evolution, demand the exposition of a series of successional forms of life; they should remember that of the lobster, common as it is around our coasts and in our markets, there is not a fisherman or observant naturalist who-has yet seen that stage in its life which unites the animal as we know it with that which we have seen it when it quits the egg; that is, no one has seen or knows any thing about the animal between the time when it is half an inch and the time when it is four inches in length. That which is true of the lobster, is like- wise true of all the higher forms of Crustacea, excepting only that of the common littoral or shore-crab (Carcinus menas). The second circumstance that I wish to notice is one that has been eluci- dated by observation in the aquarium. I have several times observed that a specimen of Pagurus, or soldier crab, will seize hold of the shell in which another, generally smaller, specimen of the same species is dwelling. I supposed that the larger animal was covetous of the shell in which the smaller dwelt. I have seen them, as I thought, endeavour to take posses- sion of such occupied shell, until their soft and tender body received such a pinch from the previous possessor as compelled them hastily to retrace their steps. Mr. Alford Lloyd has written in my note-book the following sentence :— ‘In the spring of the year, in the Hamburg Aquarium, I have seen the male of this crab take hold of the shell in which a female is contained, and carry her about for weeks together, grasping the thin edge of her shell (as of a Buccinum); and when the female is ted the male does not take away the food, as he would if a male were so fed in his vicinity.” I would here lke to state that the preservation of Crustacea by keeping them in glycerine for a few days, and then drying them, will be found to be a very superior plan to that of spreading them out without any preparation. I have specimens that have been treated two or three years with glycerine that are as flexible asa fresh crab. It will be better of course that as much of the soft parts should be removed as possible. I have also been trying, and I think with success, to preserve fish in the same way. A specimen of the Bogue (Sparus boops, L.), taken more than two months ago, is as fresh in colour and as flexible as when captured, excepting the eye, which was in a partially decomposed state when placed in the glycerine. I think, when further experi- ments have confirmed the fact, that with or without admixture with another medium, glycerine may afford a very valuable addition to the preservative agents of our museums. Among the Mollusca we have to record the capture of many specimens of Eledone This has generally been supposed to be a rare species on our coast ; but we find that Octopus vulgaris, the supposed common species, is the more difficult to obtain. Both these appear to live well and happily in captivity ; so also does Sepia officinalis. Mr. Rogers, who has charge of the pond at Plymouth, and is a most active and zealous collector of marine animals, tells me that two specimens of this last-named cuttlefish were placed in the pond on the 8th of June, 1871]. They continued doing well until the 24th, when they were seen to be in copuld, head to head, arms interlaced, and remaining stationary, resting on the bottom for about twelve minutes, then separating. On the 26th the male was killed by a dog, which seized it when in shallow water. These creatures were rarely seen far apart, usually following each other in every ON CATALOGUES OF SPECTRAL RAYS. 53 direction, swimming with equal ease either backward or forward; they were never seen to feed, but always appeared to be in search of food, after the manner of the Wrasses, moving slowly round the sides of the pond and rocks, thrust- ing their heads into holes and crevices: when disturbed, they darted through the water with great swiftness. The female died on the 6th of July, and on being opened was found to be in yery good condition, and to contain a large quantity of ova. I have been taking steps to have within the cave behind the pond a case with a glass front so constructed as to enable us to watch the habits of animals with the greatest care. The water in this pond is several degrees lower in temperature than that in the tanks of the Crystal-Palace Aquarium, a circumstance that will enable us to study marine life under still more natural conditions. I believe that students of marine life will find this pond to be a valuable instrument for the carrying out of prolonged researches in the examination of structure or the development of animals ; and they will find in the keeper an ever willing and obliging assistant and cooperator. I cannot close this Report without expressing great regret at the loss of our old friend and fellow naturalist, Jonathan Couch, of Polperro. He was a close observer and zealous lover of nature, and only wanted the advan- tages of a less secluded life to have placed him among the foremost of our naturalists. He died ata ripe old age, and, I am sorry to say, has left a widow and three children in the greatest straits of poverty, to assist whom would be a kind and generous testimony to a long and well-spent life. Preliminary Report of the Committee appointed to construct and print Catalogues of Spectral Rays arranged upon a scale of Wave-numbers* , —the Committee consisting of Dr. Hueerns, Mr. Lockyer, Professor Reyno.ps, Professor Swan, and Mr. Sronzy (Reporter). Tue reference of spectral lines to a standard scale of wave-numbers, instead of to a scale of the wave-lengths in air of a given pressure and temperature, or to any of the other scales in use, has very marked advantages. The scale of wave-numbers furnishes ¢o the theoretical inquirer the ratios between wave- lengths, which are what he chiefly wants, in the simplest and most conspi- cuous form, since a series of rays of which the wave-lengths are in geome- trical proportion will be represented by equidistant lines upon the map. No person who has not encountered the task can conceive how tedious it is to carry on a theoretical investigation with any other scale. And to the observer the scale of wave-numbers offers the advantages which have been well stated by Professor C. A. Young in the following words :—* An accurate chart of the solar spectrum on which the lines should be mapped according to ‘ inverse wave-length,’ proposed by Captain Herschel himself, I believe, as well as by Mr. Stoney and others, would sufficiently resemble the spectrum seen in a spectroscope to be equally convenient in the observatory with that of Kirch- hoff, and would be free from the reproach of arbitrariness and irregularity in its scale. Such a chart would be most gladly welcomed by all spectrosco- pists, and would immediately supersede those of Kirchhoff and Angstrém.” (See a letter from Professor Young in ‘ Nature’ of the 6th June, 1872.) * The term wave-numbers appears preferable to the equivalent term: “inverse wave- lengths” which has been hitherto used. 54 REPORT—1872. Accordingly, your Committee decided on reducing to wave-numbers all the wave-lengths, whether of solar lines or of the rays of incandescent vapours, which have been determined with sufficient precision. Mr. Charles EK. Burton has offered his services gratuitously for making the necessary reductions, and has made considerable progress with the solar spectrum, the greater part of which is now nearly ready for the press. A specimen of the catalogue of solar lines is appended to this Report, containing the lines from E to b. It is intended that this catalogue shall contain in a compact form all the most useful information that is , available, viz. :—References to the position of each line on Kirchhoff’s and Angstrém’s maps, details of the process by which the standard wave-numbers have been deduced, and indications of the intensity, width, and origin of each ray wherever these have been determined*. The rays will, moreover, be bracketed into the groups which strike the eye in looking at the spectrum, and a number will be assigned to each group which will sufficiently indicate its position on the standard scale. Your Committee have as yet only incurred an expenditure of £4 for books, maps, and preliminary printing. ‘This leaves a balance of £16 in their hands out of the grant of £20 placed at their disposal last year. It is estimated that the two catalogues which the Committee propose to publish (the Catalogue of the Principal Lines of the Solar Spectrum, and the Catalogue of Rays of Incandescent Vapours) will cost about £60. This does not include the cost of the charts, which ought to accompany the catalogues in order to render them complete. ‘The charts would increase the entire sum to be expended, including the grant already made, to about £120; but a portion of this sum would return to the Association in the form of the pro- ceeds from the sale of the catalogues and charts. Your Committee think that they could render the second catalogue more perfect if they were in a position to employ a competent person to revise and extend the determinations of the rays of incandescent vapours; and they therefore suggest that this revision be made a part of their functions, and that an addition of £50 be made to the grant for this purpose. This would increase the sum to be granted this year to £150. The Committee accordingly recommend that they be reappointed, and that this sum be placed at their disposal, in addition to the balance at present in their hands. APPENDIX. Specimen of a Catalogue of the Principal Dark Rays of the visible part of the Solar Spectrum, containing all the Rays registered by Kirchhoff and Angstrom, arranged on a scale of Standard Wave-Numbers. (The Spe- cimen contains the Rays from E to b). Column 1 gives the position on the Arbitrary Scale attached to Kirchhoff’s maps. > Column 2 reproduces the wave-lengths in,tenth metres as determined by Angstrém, after applying to the numbers of Angstrém’s list the small cor- ‘rections which he indicates at p. 29 of his memoir, “ Le Spectre Normal du Soleil.” The wave-lengths of this list are wave-lengths in air of 760 millims. pressure at Upsala, and 16°C. temperature. Column 3 contains the reciprocals of the numbers of Column 2, each mul- * Mr. Burton intends to revise the more refrangible part of the spectrum, and to supply the intensities and widths of the lines of this portion, which was not included in Kirchhoff’s investigation. tiplied by 10’. ON CATALOGUES OF SPECTRAL RAYS. 55 Each number in this column is accordingly the number of times that the corresponding wave-length in air goes into one millimetre. Column 4 contains the correction for the dispersion of air of 760 millims. pressure and 16° temperature, deduced from Ketteler’s observations (see Phil. Mag. for 1866, vol. xxxii. p. 336). per millimetre an vacuo. Column 6 indicates the intensity and width of each ray as determined by i rays coincident with solar lines, and contains some other remarks. Column 8. In the last column the rays are bracketed into the groups Column 5 contains the Standard Wave-numbers, 7. ¢. the number of waves Kirchhoff, 6 being the most intense, and g very wide, viz. about 0-15 of one degree on the Scale of Standard Wave-numbers. Column 7 enumerates the substances which have been found to emit bright which strike the eye in looking at the spectrum, and to each group is assigned a number which sufficiently indicates its position upon the Standard Scale. ° Position onlAngetriém’s Kirchhoff’s 5274-42 5272-67 5269°59 5268-67 5267°39 5265-94 5264-68 526351 5262-60 5261-11 enn a1 og <7 | 5254-21 5252-60 5251-15 5249°81 oe et SSaSSE ‘aii 5246-43 5242°86 5241-67 5239-16 5236-44 5233-72 523224 5229-14 5227°63 5226°38 5224-42 5275°19 Number of waves per millimetre in air. 1895-67 95-94 5259-78 5248°60 5234-52 96°57 97:68 98°01 98°47 99-00 99°45 99:87 1900-20 00-74 01-22 03°23 03°82 04:34 04:83 05°72 06:06 07°36 07-79 08-70 09°69 10°39 10-69 11:25 12°36 12-91 13°37 1409 Correction for the dispersion of the air. 0°53 0:53 0-535 0:54 STANDARD WAVE- NUMBERS, 1895°14 1895-41 1896-04 1897-15 1897:48 1897:94 1898°47 1898-92 1899°34 1899°67 1900-21 1902°70 1903:29 190381 1904°30 190552 1906°82 1907-25 1908:16 1909°15 191015 1910°69 191182 1912°37 1912'83 1913-55 1900°69 1904:73 1909°85 Intensity PPP RP CLOT HOOP RP ooe 8 8a ork AAs AQ | i——\ bb] WPwhbwowr Peo npne Dp reed 222 2. oo aS Sn ae on DS chen: | wseeose oo 2° Origin &e. Co. “| ca} double. Between these two rays, a ray, of cobalt. ‘Feand Ti. Accord- | cording to Ang- strom a triple ray, very strong. ae } double. Groups of Rays. Group 1898 (Group £). Very strong. Group 1904. Faint. Group 1912. Strong. 56 Position on Kirchhoff’s Arbitrary Scale. 1588'3 89°1 REPORT—1872. Angstrém’s Number of | Correction Sranparp (Intensity waye- waves per | for the Wivk: a Origin & lengths | millimetre | dispersion Sure Width Be ee in air. in air. of the air. BEES, ou 5217-28 | 1916-71 191617| le |cu. 5216-64 16-94 191640 | 3b Fe. 5215-64 17°31 1916-77 | 3b |Fe. 5214-50 17°73 1917:19| 3b Fe. 520959 | 19:54 ‘491900| 2b Ti. 520778 | 20:20 1919:66 { ea } ee am Cr. Wanged 5205-37 21-09 1920-55 5b |Cr. 5203-88 21-64 1921:10 | 5b /Feand Cr. 5201-69 22-45 1921-91 | 5b |Fe. 5199°89 23-12 1922:58| le 5198-08 23°79 ~ | 499325 | 3b (Fe. 5197-19 24-12 192358 | 2b 5195-33 24:81 1924.27 | {}> double 2bf |Mn 519424 | 25-21 192467 {4 Pt ze | double aes | 499536} 1b. [t. ian 5191-80 26°11 1925°57| 5c (Fe. 5190-68 26°33 192599 | 5b |Fe. 5188°33 27-40 192636 | 5b (Ca. 518749 27-71 192717 | 1b (Ti. 5185-24 28-55 192801 | 1b~ Fe. fart! 4g : 5183'10 29:35 1928'81 | 6g | et! Winged 4g : 5182-75 29:48 192894 | — 5179:66 30°63 1930-09 1b (Fe. 5178-27 31-15 193061; — 5176°52 31:80 193126 | 1b 5175°73 32-09 193155} 1b [Ni. parses 193253 5a 4e : 517216 33-43 1932:89 6f } bey soe Winged 4e an 5171-20 33-79 1933-25/ 6b (Fe. : : ; 6b] |b. Fe. Ni. Wing- 5168-48 | 3480 1934-26 { ee } eee : , , 6e) |b, Fe. Mg. Wing- 5166-88 35°40 1934:36 { pee | 1 ca 5165°88 35°78 193524 5b |Fe. ‘ ) ; 2b) | Fe. Wing very 5164-73 36-21 1935-67 { A } ae mium Group) Strong. Group 1932 (The Great Magnesium Group). OBSERVATIONS OF LUMINOUS METEORS. 57 Third Report of the Committee appointed to consider and report on the various Plans proposed for Legislating on the sulject of Steam- Boiler Explosions with a view to their Prevention,—the Committee con- sisting of Sir Witt1aM Farrsairn, Bart., C_E., F.R.S., &c., Joun Penn, C.E., F.R.S., Frupericx J. Bramwe t, C.H., Hueu Mason, SamveL Ricsy, THomas Scuorretp, Cuartes |, Bryrr, C.L., Tuomas Wesster, Q.C., Epwarp Easton, C.H., and Lavineron E. Fuercurr, C.E. Wuen the Committee presented their last Report on the subject of “Steam- Boiler Legislation’ to the Meeting of the British Association held at Edin- burgh, it was fully expected that the measure, having for its object the pre- vention of Steam-Boiler Explosions, which was then before Parliament, haying been introduced by John Hick, Esq., Member for Bolton, as the result of the inquiry by the Parliamentary Committee which sat upon this subject during the Sessions of 1870-71—it was fully expected that this measure would by this time not only have passed through Parliament, but also have been in active operation, so that some practical results might have been arrived at. Such, however, has not proved to be the case. The Bill, though read a first time in the House of Commons late in the Session of 1871, and reintroduced this year as early as the 7th of March, has not yet passed a second reading, having been postponed from time to time. It was thought better to wait the maturity of Mr. Hick’s Bill before assembling the Com- mittee for consultation; but this course, though considered advisable, has, owing to the delay just referred to in the progress of the Bill, prevented the Committee completing their report for presentation at this Meeting of the British Association. Under these circumstances they request an extension of time, and suggest their reappointment for another year, when they hope to complete the task assigned them. Report of the Committee, consisting of Jamus GriarsuEr, F.R.S., of the Royal Observatory, Greenwich, Roserr P. Grea, /.RS., Avex- ANDER S. Herscuet, F.R.A.S., and Cuartes Brooks, F.R.S., Secretary to the Meteorological Society, on Observations of Lumi- nous Meteors, 1871-72; drawn up by AvexanpER S. Hurscuen, F.R.A.S. Amone the objects whose special promotion it was suggested in the last Report that the Committee would undertake by combined observations during the past year, the attention of observers at several stations in Scotland and England well used to accurate and systematic registry of shooting-stars was, as in former years, frequently not unsuccessfully directed, at the request of the Com- mittee, towards recording the appearances of shooting-stars visible on the annually recurring meteoric dates in August, October, November, December, January, and April. The August meteors were somewhat more brightly visible last year than commonly, on the two successive nights of the 10th and 11th of August, and the clearness and darkness of the sky enabled a more than ordinarily large number of meteors to be carefully ohseryed. From a long list of meteor-paths 1872. B 58 REPORT—1872., recorded both at the Royal Observatory, Greenwich, and by the observers for the British Association, the heights of twenty meteors of the shower visible on the different nights of its reappearance were calculated, and several other meteors were identified as haying been doubly observed whose real paths have not yet been computed. The position of the radiant-point of the shower* was found to be, as recently pointed out by Mr. Hind in a letter in ‘ The Times’ of August 8th, more northerly than hitherto, at a pointin R. A. 35°, N. Decl. 59°, three or four degrees north-westwards from x Persei towards ¢ Cassiopeix. A few meteors of the October shower were visible on the 19th of October last; but the sky being overcast, with stormy weather, on other nights of the shower, the time and rate of frequency of their fall at the maximum intensity of the shower could not be ascertained; and from the few recorded meteor- tracks only a roughly approximate position of its radiant-point was obtained. The condition of the sky was generally little more favourable for observa- tions in November and December than in October; but on the morning of the 13th of November a clear view of the Leonids was obtained both at Stonyhurst College and at the Royal Observatory, Greenwich, while on another following morning, that of the 15th of November, they were also well seen by Professor Herschel at Newcastle-upon-Tyne; and their abundance on the latter date was considerably greater than that of the unconformable meteors from all parts which appeared at the same time with them. The distribution of the November meteor-group along the ring which forms its orbit being at pre- sent unknown, the watch for the return of the Leonids this year will be renewed for the purpose of comparative observations of their greatest rate of frequency in successive years. No accordant observations of single meteors appear to have been recorded either during the October or November star-showers. At most of the corresponding places a clear view of the December shooting. stars was obtained on the night of the 12th, while the sky was everywhere completely overcast on the 13th. Meteors appeared at the rate of ten or twelve per hour for one observer from the direction of Gemini; and the posi- tion of the radiant-point in this constellation could be pretty correctly ascer- tained by the meteor-tracks recorded on the night when they were principally observed. This appears, as in former years, to have been near @ Geminorum. On the night of the 2nd of January a favourable state of the sky permitted a considerable display of the January meteors to be seen at several of the corresponding stations, and to be simultaneously recorded at the Royal Observatory, Greenwich. The star-shower continued with about equal brightness until daybreak on the morning of the 8rd of January ; buta cloudy sky on the night of the 3rd everywhere prevented the close or a continuation of the shower from being seen. In this and the December meteor observations several examples of doubly observed shooting-stars were found, of which, with those of some other similar observations contained in these descriptions of the meteor-showers of the past year, the heights will be immediately calculated. The radiant-point of the January star-shower appears not to have altered its place sensibly in the interval since its last principal appearance in England on the 2nd of January, 1864+. The last meteoric shower of the past year which was successfully watched for by the observers was that of April 19th, 1872, when a few conspicuous meteors, radiating from the direction of Lyra, were recorded at nearly all the stations, and also at the Royal Observatory at Greenwich, and, under the direc- * Which appears, from the few observations of the shower on the 9th and 10th inst, (August 1872), to have very nearly maintained the same position in the present year, T See the volume of these Reports for 1864, p. 98, OBSERVATIONS OF LUMINOUS METEORS. 59 tion of the Rey. R. Main, by Mr. Lucas at the Radcliffe Observatory at Oxford. The watch at the latter place was continued during the night of the 19-20th of April until the morning hours, and the Lyraids continued to be more and more abundant until daybreak. The position of the radiant-point was close to that found in the former observations of 1864*. The prevalence of some other radiant-points of shooting-stars chiefly producing, it appears, bright meteors during the months of March, April, and May was discernible ; and the heights of two bright meteors from different radiant-points that appeared on the night of the 19th of April will be approximately obtained from double and triple observations of their apparent paths which were then recorded. The heights of some large meteors seen on other nights of the year have also been determined with some certainty from corresponding observations of them at distant places, of which a short description is given, with that of the principal observations from which they are derived. Large meteors have been seen in more than ordinary numbers during the past year; and the informa- tion respecting several of these meteors which has been received by the Com- mittee is included in a general list in continuation of some former notes of meteors of the largest class. But two aérolites appear to have fallen during the years 1871-72; the first at Searsmont, in the United States, on the 21st of May, 1871, and the second in November, 1871, at Montereau, in France. At the conclusion of the Report the contribution of some recent valuable additions to meteoric literature by the Italian astronomers and observers of shooting-stars, Prof. Schiaparelli and Signor Denza, in combination with a well-known representative of meteoric science in Germany, Dr. G. von Boguslawski, is briefly noticed and described; and in the last place a long list of radiant-points placed in comparison with each other in a single Table by Mr. Greg at the close of this Report, forms a complete comparative index t of the epochs and positions of all the meteoric showers included in the general lists hitherto published for the northern hemisphere. Great improvements of this Table will, it cannot be doubted, be made by reducing the many meteor-tracks, of which, since the appearance of the last printed meteor-catalogue in these Reports, a large number of descriptions have been received. To enable them to accomplish this undertaking, the continu- ation of the Committee’s operations, and of a grant to support them in execu- ting charts and tracings, is earnestly recommended to the British Association. The watchfulness of observers on every fine night when favourable opportu- nities present themselves for recording the occasional appearances of shooting- stars, in order to contribute fresh materials for the same purpose, is once more appealed to, in addition to the nights of annual recurrence of meteor-showers, of which, as before, due notice will be regularly communicated to them by the Committee, and suitable means will be furnished to them to enable them to assist these objects by their observations, to which their attention will again be in- yited at the returns of the several meteoric epochs, as in former years. J, Murnors pouBLY onspRVED. Among the meteors observed during the simultaneous watch for the annual meteor-shower of August, December, January, and April, in 1871 and 1872, Several accordant observations of individual meteors were found, enabling their real heights to be satisfactorily ascertained. A list of such accordances * See the volume of these Reports for 1864, p. 98, + Anequally extensive list by Dr. J. F. Schmidt, of Athens (Astronomische Nachrichten, No. 1756, 1869), unknown to the Committee when the accompanying Table was com- piled, is, for the present. omitted from its comparisons, , ¥ 60 REPORT—1872. on the nights of the 10th and 11th of August, 1871, with the results obtained from them as computed by Professor Herschel, appears in the ‘ Quarterly Journal of the Meteorological Society’ for November 1871, from which the annexed figure is copied, showing the real heights of first appearance and of Reference numbers. Ay Ie 9S 5.6. 77 8 9) BOTT 2: 18, 41S Se Lets) oes Tage. 120 120 100 100. s ira} 3 2 ay & a 2 o i ‘ vo 3 g0j/---- 80 3 vo 8 : 3 -} & 2 | FI 2 604-- 60 2 s 5 ie 2 Ss "234 or, a =) Q ee ag ~~» ~~ e 5 isa) y 20 20 0 0 Sea-level. Real Heights of twenty Shooting-stars, doubly observed in England on the nights of the 9th to 12th of August, 1871, above the surface of the earth. disappearance of twenty shooting-stars of last year’s August shower, together with their average real height. On comparing together the actual hori- zontal distances from the observers at which their apparent points of dis- appearance had been accurately recorded, it appears that a circle 160 miles in diameter represented a field of view within which four fifths of all the terminations of the meteors’ visible paths were seen and recorded by the observers, mapping their apparent courses at its centre; and that, on the average, three or four times as many accordances of observations are likely to be obtained by observers at stations separated from each other by distances of between forty and eighty miles, as at places either nearer to or more distant from each other than about these limits. The average heights of the meteors thus observed above the carth’s surface was 86 miles at first appearance, and 52°5 miles at disappearance; the average length of path 46 miles, and the average velocity of nine Perseids contained in the list 51 miles per second. The difficulty of estimating exactly the small duration of their rapid flights, and a tendency, by aligning their apparent OBSERVATIONS OF LUMINOUS METEORS. 61 courses with the brightest neighbouring fixed stars, to overstate rather than to underrate the apparent length of their visible flights, will perhaps account for the excessive real velocity of the Perseids obtained in these results of the Simultaneous observations. The velocity of a single meteor of the shower; as bright as Sirius (the first meteor shown in the diagram), unconformable to Perseus, and directed from the radiant-point in Pegasus, was somewhat more exactly obtained, both its apparent path and its duration being very earefully observed by Mr. Wood at Birmingham and Mr. Clark at York, _ whose observations were in excellent agreement. The real length of the path of this meteor was_38 miles, and its resulting real velocity was 19 miles per second. On comparing together the observations of the shooting-stars recorded at Greenwich with those seen at the British-Association stations during the same August shower, several perfectly accordant observations were found on the night of the 11th; and but few satisfactory identifications of meteors doubly observed on the night of the 10th of August, excepting that of the brightest (at 10" 51™ p.m, as noticed in the following descriptions of the shower), could be detected. The following list contains a general description of the various shooting-stars which appear to have been doubly observed at the Royal Observatory, Greenwich (and by the observers at other stations), on the night of the 11th of August, and on the other nights of simultaneous watch kept for the reappearance of the annual meteor-showers which haye been visible during the past year. A few double observations of shooting-stars are also contained in the accom- panying list of bright meteors, and in the detailed accounts which will shortly be given of the observations of the meteoric showers. The meteor No. 7, whose real height is figured in the above diagram from observations at York, at Hawkhurst, and in London, was also seen at the Royal Observatory, Greenwich, and its apparent path was there recorded at 11" 14™ 59° p.m. on the 11th of August. The redetermination of the real height of this meteor by comparison of the new observation with the former ones, and the computation of the several meteor-heights to be derived from the additional observations contained in this Report, will afford interesting materials for future consideration. The last meteor in the accompanying list, on the 19th of April last, will be seen to have been triply observed at York, Wisbeach, and Hawkhurst. The heights determined from the observations at the first two places are 66 miles at first appearance, and 41 miles at disappearance. But if the observation at Hawkhurst is correct, the meteor probably moved at an elevation of not more than 50 or 55 miles at first appearance and 30 or 35 miles at disappearance. From the former observations the length of its visible path was 90 miles ; but in the latter case it would not exceed 70 miles ; and if the observations at York and Hawkhurst only are employed, as affording the widest parallax, it would be somewhat less. The duration of its flight was probably underestimated at York at half a second, and overestimated at Wisbeach at 3 seconds. The ave- rage duration is 13 second, giving the probable velocity of the meteor not more than 40 miles per second ; while the actual velocity of the Lyraids, calculated from the astronomical theory of the great April meteor-group, is 30 miles per second, The recorded paths of this member of the shower diverged very ex- actly from a common radiant-point between z and 6 Herculis, about 20° from the usually observed centre of divergence of the meteor-group in Lyra. The estimated height of a bright meteor seen on the 31st of August last was also obtained from accordant observations of its apparent path at Ross 62 in Herefordshire and at Hawkhurst, as will shortly be noticed in its particular description. ‘The confirmations of the astronomical theory of large meteors REPORT—1872. and shooting-stars, and the advance of our existing knowledge of the laws that regulate their courses, characteristic rates of motion and appearance, and Date. 1871. Aug.11 11 1] 1] 11 1] 11 1) 11| 11 11 11 11| 1]} 1) Hour. 10 11 ll ll 11 11 ll Te ll il 12 14 30 30 48 59 Place of Observation. Hawkhurst Royal Observa- tory, Greenwich. Hawkhurst eevees Royal Observa- tory, Greenwich. Royal Observa- tory, Greenwich. Bolton, Cheshire Royal Observa- tory, Greenwich. Royal Observa- tory, Greenwich. Sheoting-stars doubly observed during the Annu Apparent Magnitude, as per Stars. Srd Mag. ...cceeseres Ist Mag. cc. sceceses Ist Mag. cserereseee 2nd mag. From Ist mag. to} size of 2. Brighter than 2 ...| PTV eR Pee eee eee eer 1St MAG. rsevscceess Ibid ..............-|Brighter than Ist- mag. * Regent’s Park, |Ist mag. ...+06...00 London, Birmingham .../Brighter than Ist- mag, * TDG ise caseceassnee Brighter than Ist- mag. * |Royal Observa- {Ist mag. ..........4 tory, Greenwich. Hawkhurst ...... Dh tecensitya sasaenre® Brighter than Ist-| mag. * |Bluish white .| Bluish white . Bluish white . beeen eee eee eenesleoee Bluish white . Yellowish...... ! eee eee Eee e ree et Bluish white 15 second Duration. Very swift . 0°7 second weet e ee eeeeenenee 1:0 second ... 15 second .. 1'3 second ener 0-7 second .. More than 1)Across 0 Urse Ma second, see eeeeene serene 1°5 second 1:0 second 1 second ...|From ...|From 350°+77° .../From direction Position. e= o= '|Prom 345°+80° tion of o Cygni. : a= o= From 265°-++62° to 247 +45 From direction 0 y Cygni shot cross 0 Sagitte. . 24> From 326°+ 8° to 314°5—12 tion of e Cam lopardi. . Uz o= From 294°+33° to 28 +25 .|From direction o « Cassiopeiz pas sed across 6 Per: sel, joris to 12 Canu Venaticorum. : a= O= From 180°+76° to 191 +51 8°+4+56° to 240 +58 to 265 +71: . From e¢ Urse joris. Fell t wards horizon. e e= O= \rom 350°-+-76° to 27 +60 « Androme passed about to the right B Andromeda. OBSERVATIONS OF LUMINOUS METEORS. 63 the dates of their greatest frequency, may be greatly assisted by the accounts of those who are favourably situated to observe them, even without the special accuracy which should yet always be aimed at in descriptions of these hitherto but partially investigated phenomena. ‘Meteoric Showers recorded in the years 1871 and 1872. Length of Path. Pee eee e eres Prete tweens SOO renee eeneee PE OR eee eererecs Teer ee eeeee + PPPAO Pete eeeeee PPE ereeeele eee eteerverls wer eeeeeeeeeler Direction. TOR e ere emer e reese eee ea esarenarenees seen eens Pee eee m en eeeeee ee eee eeeeeaeen Appearance ; Remarks. Left a slender streak ...cscccseeeees Left a streak MeL @ StKEAK eveasccareienenveeei sis No streak HAO meee ere e ener eesracean see eeneeee ee eee ee Pe Oe ee areatane Cevereeereeeee see eeeene Peon ee beeen arernee seoveesetencees Oe been ee eeee Cone e enter eenene eeeeee Radiant-point ¢ Cassiopeix .. ‘Fell towards the left at an in- clination of 45°. [From direction of Cygnus] ... [from direction of Cygnus] ... Train not bright, but lasted 34 seconds. [Identical with me- teors at Hawkhurst, 105 14™, and London (Regent’s Park), 10" 15".] Left a fine streak, which remained visible for 3 seconds. No particulars of appearance re- corded. Left a streak ......... dacenesapvsasi: Lieft a fine strealc satcecasesesseress Path imperfectly seen .sssseeeeee Left a long train on its course. (From w Cephei to 6 Draconis.) .|(From y Cephei to W Draconis)... Left a fine streak ... seen eerreeerers Left a broad fine streak. (From y Cephei to just below e Cassi- opeiz.) Left a magnificent streak. Observer. Miss Herschel. .|Wm. Marriott. Miss Ilerschel. T. Wright, J. E. Clark. riott. iR. P, Greg. Wm. Marriott. W. C. Nash. T. Crumplen. W. IT. Wood. Id. Wm. Marriott. Miss F. Herschel. Win. Marriott. iT. Wright & Wm. Date. 187]. Aug.11 1] ll 11 11 1] 11 11 Dec. 12 12 1872. Jan. 2 64 Hour. hm i s 11 45 30 -11 46 56 11 50 30 11 51 10 11 54 35 155-0 1273) 0 12 4 4 12°29 0 12 29 25 1013 0 1017 0 (time by watch, ll 430 2) ll 4 30 2} Yi 5 30 Yawkhurst Hawkhurst uncertain) Place of Observation. Royal Observa- tory, Greenwich. Hawkhurst ...... Birmingham ... UW erG bsnascern Wage? Royal Observa- tory, Greenwich. Royal Observa- tory, Greenwich. | Tooting (near London). Hawkhurst ...... |Royal Observa- tory, Greenwich. |Eaton Square, London. Tooting, near London. REPORT—1872. Apparent Magnitude, as per Stars. Brighter than 2b... mag. * SLO MAP, ors...045 Royal Observa- |=Ist mag. ......... tory, Greenwich. TDI... .ccecsccovve+|2NG MAL. .ceccoesses SE MAG: sceecesscees 3rd Mag. ..seeerese. ISt Mae. cs.scenseee Brighter than 1st- mag. * Mange! tees sssenneeee ss Brighter than Ist- 'Bluish white . .\0°7 second .. 2nd Mag....eerreeeee | Ist mag. ...++. sevessts MAID, (kaceacren scene Wan toate sie 2nd mag....+.. Pica As bright as Jupiter Duration. .|Slow speed ... .|1°3 second ... 0°83 second ... 11°2 second ... JL second ...... «(15 second ... il second ...... .From « Draconis '(0°3 second ... eee ee nett te eeeee '|From 160°-+55° Position. a= 6= From 23°+66° to 8 +62 | From direction of dromede. e— — From 340°-+30° to 355 +42 From « Pegasi in direction of y Pegasi. passed across Bodtis. a From 332°+57° to 310 +36 From 286°-+20° to 278 + 6 From 323°+51° to 288 +20 From ¢ Cygni to y}| Aquile. 2 = From 80°+9°5° to 74 +4+4°5 From 75°+28° to 60 +23 From a point be tween @ and ff Urse - Majori passed in the d rection of 0 Aull rig. Disappeared at 4 (m,w) Lyncis, Course from y Ursz Majoris, be ginning 6° short of that star. e= O= to 135 +44 Length of ‘Path. Beene tener eersteee 20° Peereere eet er naeeereerenrle .|[From Pegasus] wee taeneeeenle OBSERVATIONS OF LUMINOUS METEORS. Direction. [Radiant in Pegasus] se eeee eer eeceee weeee ee ee enone eee: ..|Left a very fine streak .|Left no streak. Appearance; Remarks, Brilliant nucleus and broad train. (From the left of 0 Cassiopeize} to beyond y Cassiopeiz.) Left a splendid train .......04 Left no streak. (From » Pegasi to below c, « Andromedz.) Left a streak Left a streak ......... Siewaits tue den et (From head stars of Cepheus to « Andromedz.) .|From 4 (6 Cygni, ¢ Aquile) to « Aquilz, and 10° beyond that star. Leftiraystveak: \..messadensees sagantae Left a streak for 4 second. (Along the axis of Cygnus, and just south of it, as mapped.) .../Position probably correct within 4° each way. (From 4 (8, 1) Tauri shot to a little below the Pleiades, disappearing some degrees before reaching them.) Left a streak ...... pOCnOUESIOOSTEIO: Left no streak.ec...s...ccccsssceeeees Left a streak. Position, as mapped, fairly well observed. (From a little south of 6 toa little south of « Ursz Majoris). 65 Observer. Miss I. Herschel. Wm. Marriott. ‘Miss F. Herschel, Wm. Marriott. W. C. Nash. W. H. Wood. Id. W. C. Nash. Miss Herschel. W. C. Nash. II. W. Jackson. Miss J. Herschel. Wm. Marriott. A. 8. Herschel. H. W. Jackson. REPORT—1872. Apparent : Magnitude, Colour. Duration. Position. as per Stars, Place of tip our - Date Hour. Observation. | i | | =e 1872.; h m_ s Jan. 2} 11 29 © |Hawkhurst ...... SSSUIUS cesscesecee|eoeeceeeeenes Jénve| -sceueqecenadteaed From about y Cas- a, 8 Arietis. 0 \Eatoh Square, |Brighter than Ist-|White ......... |2 seconds...... From 3 («, B) Au- London. mag. * rigee to A Tauri. OMbid-Senrercatregces SIGMA. cs psessseess|| WHILE secnesree 1-4 second .../From 130°+6'5° to 1l4 —6 0 |Hawkhurst ...... = CastorAaeioccs i ove tints asdasoneaaced| tse ben Maeaeee .»»|From 115°+29° to 91+ 4 OT bid) Hiaesedsdetedes| USEIMA ES axanks aideslorvncedevana sdanec|ansveairseenseeyin From B Camelo pardi past « Per- sei, and past the Pleiades. 54 30 |Eaton Square, |=Sirius ..... «eee White, then [2 seconds...... a= oe London. orange. From 96°+44° | to 86 +10 0 |Wisbeach, Cam-|Ist mag. vcs. Yellow ...+eeee+/3 SCCOUAS, ,.40 a= O= bridgeshire. | From 232°+73° E to 107 +63 27 30 |Hawkhurst ...... Ist Mag. ..secsevececlecetoeceesrssecees[seeaseeeseeeeeeeee LOM 45 °--56° to 50 +50 O: |Norkeyeteersesets == SINS tare cnsatetis WGIGG) cescesaee 0°5 second .../ From 228°5°429° to 203 +12 II. Lancs Merzors. In addition to the occurrences of this kind of whose appearance accounts were received by the Committee since their last Report, the following list describes some conspicuous meteors of which no particulars were contained in previous Reports :— 1. 1851, July 30, 8" 10™ p.m. (local time).—Two days after the total eclipse of the sun in the north of Europe in that year, a large fireball was seen in Denmark and on the coasts of the Baltic, in bright evening light ; and it was described in many of the contemporary local newspapers. The OBSERVATIONS OF LUMINOUS METEORS, 67 wn of Direction. Appearance ; Remarks. Observer. ee easevsccs|oussovcccccocccsccssesssccssssseceenas(Briiant; left'a slight streak...... Miss M. R. Herschel. MMGseieesercess0s|s0 scnctacnocsscssccescsscccovsccsessoeee(Drightest in the last half of its|A. S. Herschel. course. Mileaecasscs.|o0 PidevagesdaxecdiccrdageeiveVves Nt SW one or Worretieta Obsery rs Place Apparent course and appearance of a Jarge Meteor seen at Copenhagen 1851, July 30, evening, by Pp. J. Winstrup. and third it seemed to be mixed with flame of rapidly increasing brightness ; and in the last third part of this portion of the meteor’s flight, its nucleus was plainly visible, of intense whiteness and brilliancy at the centre, and surrounded with duller red light towards the border, which was of the same width as the smoke-wreath. It became extinguished at 6, and from this point to ¢ three more small cloud triangles, like those first formed, were added in quick succession to its length. ‘The earlier portions of the smoke- wreath had by this time entirely disappeared, the meteor taking not more than three or four seconds to produce the cloud column, which was also the time taken by this part of the smoke-wreath and by each of the cloud triangles to disappear; so that the whole duration of visibility of the pheno- menon was about fifteen seconds. Immediately after its disappearance, the blue sky at that place remained as clear and as bright as it had been before the meteor’s passage. The cloud-substance of the triangles first formed was bluish white, like the smoke of gunpowder, while that in the upper part of the smoke-column became quite dark as it disappeared. By marking the first and last points of the meteor’s course (a, ¢) with reference to the houses of a neighbouring street, and pacing their distance from his point of view, the apparent path of the meteor, as it was thus ohecivae by Mr, Winstrup, appears to have been ascertained as follows :— Point of commencement, a, altitude 7°, 52° east from south. Point of disappearance, c, altitude 30°, 19° east from south, Apparent length of the meteor’s course, a c, about 42°. Inclination of its apparent course to the horizon, about 38°. OBSERVATIONS OF LUMINOUS METEORS, 69 2. In the ‘Standard’ of September 15, 1869, Mr. F. P. Bullock describes a remarkably bright meteor, which he saw at Cheltenham, at 10" 8™ p.m., on the 12th of that month, passing rapidly, and with an extraordinary long course, over a complete quarter of the sky. 3. The following observations of rather bright meteors were communi- eated, with some of lesser magnitude noted during previous years, by Mr. J, E. Clark :— 1869, September 20, 6" 46™ p.a.—A meteor about + of the apparent size of the moon was seen by Mr. A. K. Brown, Mr. 8. P. Thomson, and by other observers, at Denbydale, near Huddersfield, of pale yellow light, apparently not much stronger than that of Saturn, and changing to red. It fell about 15° in 24 seconds, nearly vertically, to a point about 15° above the east horizon, followed by a streak or tail of sparks, which became redder, like the nucleus, towards the end of its course. 1869, December 21, 8" 15™ p.w.—Near Leominster, Mr. J. E. Southall observed a meteor of yellow colour, and of about the greatest brilliancy of the planet Venus, descending vertically 123° in half a second from a point in R. A. 97°, S. Decl. 7°, to R. A. 86°, S. Decl. 18°. The meteor was visible through light clouds, which obscured the view of any streak or sparks which may have accompanied it in its course. 4, At a meeting of the Natural History and Philosophical Society of Derry, in Ireland, on March 4, 1870, Mr. William Harte described some observations of a remarkable meteor which passed over Donegal on the night of the 27th of December 1869. 5. 1870, July 25, evening.—Soon after dark, a brilliant meteor was observed in Kent and at other places near the English Channel. At Dover it was seen to rise almost perpendicularly from the sea horizon in the east, increasing in splendour until it disappeared overhead. The first effect of its very striking and unusual upward course was to produce an irresistible impression that it was a signal rocket or other artificial light fired from some distant vessel on the sea. Some current descriptions of this fireball, which appeared in the daily journals at the time, have unfortunately escaped the notice of the Committee. 6. On the 16th of October, 1870, descriptions of two bright meteors received by the Committee appear to indicate some close connexion from their resemblance, although, from their recorded positions and from a slight interval between their times of appearance, they appear to be distinct. The first, which appeared to Mr. J. E. Clark and Mr. 8. Giles, at York, at 8" 25™ p.m., of red colour, increasing from the apparent brightness of a fourth-magnitude star to that of Venus, described a short course of 8° or 9° in three or four seconds, from a point in R. A. 22°, N. Decl. 20°, to R. A. 34°, N. Decl. 16°, leaving a few sparks, but no visible streak upon its course. At 8" 28™ p.a., on the same evening, a meteor brighter than a first-magni- tude star, and in every other respect of perfectly similar description with that observed at York, was seen by Mr. William Marriott, at Greenwich, describing, in the same time, an apparent course of the same length, in the northern sky, from the star ¢ towards the star a in Draco. The meteor seen at York appeared in the south-east, at such a considerable distance from the direction indicated by the Greenwich observations as to admit of no possible consideration of their identity by the supposition of ordinary errors of obser- vation. But the remarkable resemblance of their descriptions and their nearly simultaneous appearance, if not attributable to the earth’s passage at the time through a common meteor-system, is yet a very similar occurrence 70 f REPORT-——1872, to the pairs and groups of meteors which are sometimes observed to appear in very brief succession in ordinary star-showers. The radiant-point of the pair, if these meteors might be so regarded, is between the constellations Cygnus and Vulpecula. But from their close vicinity, respectively, to the radiants R, and BG,, in Musca, and in the neighbourhood of Draco, which first present themselves about the middle of October, it appears more probable that their remarkably foreshortened courses may be clearly individualized as distinct, and that they were evidently members, respectively, of those well- marked, and widely separated showers. A similar instance of coincidence, but apparently without real connexion, will shortly be noticed in a future age. : 7. Another bright meteor, from one of the latter radiant-points, R,, was recorded by Mr. Wood, at Birmingham, at 10" 7™ p.m. on the 1st of Novem- ber 1870; brighter than Sirius, white, and moving for two seconds in a short course close to the apparent place of the last meteor seen at York, from R. A. 27°, N. Decl. 21°, to y Arietis. At 10" 27™ a second-magnitude meteor, with a very short course, passed, leaving a streak across the Pleiades, proceeding from the same radiant-point, from which a few other meteors, noticed by Mr. Wood on that night, were also directed. In a note to the latter appearance, he observes that “a writer in the ‘ Times,’ of about that date, describes an ‘ Astronomical Phenomenon,’ which was ‘ a sudden light- ing of the Pleiades of momentary duration,’ and which took place twice on the same night. I observed the same effect produced by this meteor; and it is evidently owing to the proximity of the radiant R, to the Pleiades, causing the meteors to be seen foreshortened when they happen to present themselves in the position named.” Large Meteors observed since the presentation of the last Report. 1871, August 13, 8" 30™ p.m.—In a letter to Mr. Glaisher, Mr. W. J. Miller communicates the following observation of a fireball seen by him in August last at Glasgow :—“ On the 13th inst., about 8" 30™ p.m, I observed, about due north from the western part of this city, a meteor making a nearly vertical descent ; it tended slightly westwards. The elevation might be about 25° or 30°; and the twilight was still strong. The effect on the eye was more of a flash of lightning, or the sudden appearance of the new moon, than any thing I can compare it to. The sky being clear, there could be no lightning of this description.” 1871, August 21, about 9° p.a.—The following description of a large meteor seen at Knocklong, Limerick, was communicated to the Committee by Mr. W. F. Denning in a letter from the observer, Mr. Jeremiah Henly, who writes :—‘‘ The meteor was visible a few minutes after 9 o’clock. It seemed to issue from about Polaris, and travelled across the heavens for a space of at least 7° or 8° [? 70° or 80°] in the direction of the constellation Hercules. As it passed throngh the atmosphere, it seemed to leave a brilliant track of fire across the heavens, which continued visible for about ten seconds.” 1871, August 31, about 9° 45" rp.w.—A meteor of very remarkable ap- pearance was simultaneously observed at Hawkhurst (Kent) and at Ross (Herefordshire) under very favourable circumstances for determining its real height. The attention of a lady, Miss Strong, who observed the meteor near Ross, being directed, when it appeared, to the unclouded appearance of the full moon, which had then risen some 15° above the E.S.E. horizon ; of a sudden the meteor came into view, with leisurely speed and with surprising lumi- OBSERVATIONS OF LUMINOUS METEORS. 71 nosity, issuing, apparently, from close behind and from the centre of the moon’s side. From this point of first appearance it glided slowly eastward, leaving on its track a train of Meteor, The Moon. gold-coloured sparks as broad and bright and compact, apparently, as the nucleus which it pur- sued. After advancing for a considerable space ~ the nucleus disappeared instantaneously, as if it were suddenly extinguished ; and the sweeping portion of the train nearest to the moon broke into separate sparks, while the train, along its whole length, lay scattered along the sky like sparkling dust, which quickly faded away. In the absence of any neighbouring stars, which were then only beginning to glimmer faintly in the evening light, no more exact description of its apparent course, after leaving the moon’s side, could be successfully attempted. A complete view of the meteor from its point of commencement, in a cloudless sky, was also obtained by Professor Herschel at Hawkhurst, in Kent, where it passed across the sky, at a considerable elevation, and with a long and brilliant course, at about 9" 44™ p.m. In the first portion of its flight, which commenced close to the stars g, 7 Vulpecule, it increased from the brightness of a first-magnitude star to that of Sirius; and thence, while passing near the star ¢ Cygni, it was accompanied on its course as far as the star » Pegasi by a uniform and compact train of yellow sparks, of nearly the same brightness, and of twice the apparent diameter of the nucleus. The brightness of the meteor, in this part of its course, was but little less, and it at length exceeded that of the planet Venus at its greatest brilliancy, while its head was of the same yellow colour as the wide track of light which formed its train. At the latter point the bright nucleus disappeared, and the luminous train of sparks ceased, while a small spark, about as bright as a fourth-magnitude star, with intermittent light, could be traced pursuing its course about 8° or 9° further, to a point about 2° below the star v Pegasi, where it finally disappeared. The meteor moved over its whole apparent course of 40° in six seconds; and the bright belt of light, about 6’ in apparent width and 20° in length, which remained on its track, was visible for three or four seconds afterwards, resolving itself into small sparks, which appeared to move forwards along the streak in the direction in which the meteor had advanced. The perfect continuity of the long train of sparks, its little inferior brightness, similar golden-yellow colour, and general resem- blance to the head, which it enclosed so completely on both sides as to exceed it considerably in width, and the steady forward motion of the meteor, caused it to strikingly resemble the sudden and horizontal discharge of a distant rocket. Such features of special interest in its appearance will, it may be hoped, from its brightness, and from the clearness of the sky on that even- ing, haye attracted the attention of observers at other places, besides the two widely distant points of observation here recorded, at which its appearance 792 REPORT—1872, and the position of its apparent path in the heavens were noted under the most favourable conditions. The point of commencement of the meteor’s course is found with consider- able certainty, from the two foregoing observations, to have been situated at a height of 44 miles above the sea, over a point in Pevensey Bay, about 6 miles from the Sussex coast. The real course of the meteor from this point was, nearly, from due west to due east, with a very slight inclination to the horizon ; or that direction of its real flight is most nearly accordant with the observations. The point of disappearance of the small spark which advanced furthest along its flight was, hence, at a little lower elevation, of about 40 miles above the sea, close to the French coast, near Boulogne. Assuming that the moon’s apparent place at Ross was exactly upon the apparent course of the meteor, which appears to be really signified by the remarkable obser- vation that, as seen from that locality, the meteor appeared to issue from close behind the moon, the agreement of this point with that of the meteor’s first appearance, as observed at Hawkhurst, in a graphical point of view, is so accurate and precise, that the real position of this point of the meteor’s course, as above determined, may be satisfactorily assumed, without any material corrections, as being substantially correct. On the other hand, admitting that, for the purpose of calculation, the description of the remaining portion of the meteor’s apparent course, as observed at Ross, is obviously incomplete, the narrow limits between which (conformably to the rough notes and sketches of its appearance there, and to the remaining portion of its apparent track as mapped at Hawkhurst) the meteor can be supposed to have moved, allows a very important conclusion to be drawn from a complete examination of the remaining materials which were recorded concerning its apparent course. If not exactly in the true west point of the horizon, the apparent radiant-point from which the meteor was directed can yet not have been far removed (not exceeding about 20°) southwards from this point, nor at any great elevation (not exceeding about 30°) above the western horizon, and it proceeded apparently from the radiant Q,, near @ Herculis, chiefly con- spicuous in August; so that the direction of its real course relatively to the earth did not differ greatly (not more than 45) from that of the earth’s real motion in its orbit at the time when the meteor appeared, which was nearly from the 8.W. point of the horizon. The greatest length which can be assigned to the meteor’s real path is rather less than 42 miles, derived from the supposition, as above assumed, that the meteor’s real course was almost horizontal and almost exactly directed from the west. But if the meteor’s real path was more inclined than this, it must also have been shorter (and with the above extreme inclination, which it might be possible to assign to it from the observations, its length would not exceed 33 miles*). As the whole duration of the meteor’s flight, observed at Hawkhurst, was six seconds well counted while the meteor was in sight, the real velocity of its motion cannot haye much exceeded seven miles per second; and under certain possible assumptions of its apparent course at Ross, it may even have been less than this, or the meteor may have travelled with a real speed of only 53 miles per second. While the average real velocity of shooting-stars * By supposing the meteor, as seen at Ross, after issuing from near the moon’s place, to have descended obliquely at an angle of 45° with the horizon, towards the left. The drawings represent the meteor as slightly ascending, rather than descending; and it is described as advancing a considerable space, and producing a luminous train of some length, after leaving the moon’s side. ‘This representation of the meteor’s apparent course at Ross, when compared with the Hawkhurst observation, agrees exactly with a perfectly horizontal real course, directed from about 4° south from west. OBSERVATIONS OF LUMINOUS METEORS, 73 relatively to the earth is fully 30 miles per second, it follows that in this case, where the meteor was evidently overtaking the earth, moving nearly in the same direction with it, its real velocity in space must have exceeded that of the earth’s motion in its orbit by not much more than 7 miles per second. The excess of the velocity of a meteor overtaking the earth directly in a para- bolic orbit, above that of the earth’s mean motion in its own nearly circular orbit, is found by Dr. Weiss to be about 93 miles per second*. The following letter in ‘ Nature,’ May 16, 1872, from Mr. G. C, Thomson, at -Cardiff, affords another instance of bright meteors noted during the past year, the real course of which appears to have not differed greatly in their direction from that of the earth’s motion in its orbit, at the time of their appearance :—‘‘TI observed a meteor at about half-past eleven on the night of the 8th inst., in the constellation Scorpio, which passed very close to the star Antares, travelling from right to left. It appears to me worth remark- ing, from the fact of its course lying very near and roughly parallel to that part of the ecliptic which corresponded to the earth’s position in her orbit. It traversed some 8° or 10° of arc, and was visible for three or four seconds, gradually increasing in brightness until it was nearly on a par with Antares, which star it also resembled in colour. Its slow apparent motion imme- diately suggested the idea that it was moving in the same plane and direction as the earth, in fact that it was overtaking us in an orbit just outside our own. The course of another meteor seen about half an hour earlier from a westerly window, and described to me as not inferior to Jupiter in brightness, appears also to have lain in the direction of the ecliptic, but from left to right, in the neighbourhood of the constellations Gemini, Cancer, or Leo. It is rash to generalize from insufficient data; but I conceive these meteors may both have belonged to a system whose orbit lies nearly in the plane of the earth’s orbit, the apparent retrograde motion of the last named being caused by the direction of its path crossing our orbit at a point behind the earth’s then place, instead of in advance of it.” The two meteors here noticed appear to have belonged to the meteor-system denoted by the radiant-point Y, presenting itself during the first half of May, near the centre of the con- stellation Leo, and scarcely more than 20° distant from the point in the ecliptic from which the earth’s motion is directed during the early portion of that month. The apparent motion of the two meteors in opposite directions (in the former case moying eastwards towards Scorpius, and in the latter case westwards towards the constellations Gemini and Cancer) is most readily explained by the effect of perspective upon their, probably, not far from really parallel courses, joined with the circumstance that in their appearance above the observer’s horizon, at Cardiff, the meteors successively presented themselves upon opposite sides of their common radiant-point. In relation to the probable positions of their apparent radiant-centres, both * As a convenient means of exactly estimating the very short intervals of time occupied by meteors in their flight, it may be suggested to observers to repeat the English alpha- bet (or as many letters of it as are required, rapidly and distinctly) immediately after the meteor’s appearance. With ordinary fluency of pronunciation one alphabet occupies about four seconds, and fifteen alphabets can usually be repeated in one minute, the time occupied by a single syllable, or by one letter of the alphabet, when thus repeated, being about one-sixth part of a second. By beginning the repetition during or immediately after the meteor’s passage, and continuing it during an equal period of time to that in which it appeared to move, a pretty exact estimate of the interval may thus be obtained from memory. In ordinary cases (where the time of the meteor’s passage does not allow more than five or six letters of the alphabet to be repeated) the observation may be repeated ‘once or twice, and by counting the number of letters, in each case, a more exact average determination, amounting generally to a very close approximation, may be obtained, 1872. G WA REPORT—1872. the bright or reddish colour and the apparent speed of motion of meteors in their flight present a very important and interesting subject of study and of further observation. 1871, September 2, about 8" 15™ p.m.—On this and the following dates some bright meteors, proceeding apparently from different radiant-points from that in Hercules of the meteor last described, were noticed, and the following was recorded by Mr. J. M. Wilson*, as it appeared to him on the above evening, in the fading twilight, and with a slightly clouded sky, and to other persons at Croakbourne, in the Isle of Man. The meteor appeared in the west, and presented a visible disk of about the apparent size of an cighth of the moon’s surface. As it increased in size, the nucleus broke into three following and connected portions, the foremost and brightest of which was white ; and a luminous streak remained for about one second upon the meteor’s course. It moved for two or three seconds, with a slow and uniform motion, over a space of about 45°, descending nearly vertically in the west, from between the stars y, « Herculis, crossing Corona to a little below ¢ Bootis, where it finally disappeared, about 15° above the horizon. 1871, September 4, 9" 30™ p.m.—At Brancepeth, near Durham, Mr. Joseph DAvsen doteminicted the following description of a very fritadt meteor which he observed at the above hour; his shadow cast before him as strongly as during bright full moonlight, causing him to turn in time to see the meteor in its descent. It was first seen passing Polaris and descending towards Ursa Major (see the accompanying sketch); intensely white, like the ¢ Polaris »,/ ’ ? é i ud i 4 wih P ss PATTY i e Li / ig! \ hs iff | ' Ursa. Geriady Major iy ota ° Le Point of the meteor’s explosion and subsequent appearance. Meteor scen at Brancepeth, Durham, 9h 30m r.m., September 4, 1871. magnesium light, and bursting into seven fragments as it approached that constellation. The two larger fragments appeared each to be not less than the head of the meteor before its disruption, and all were white, fringed with blue, and died out as sparks falling towards the earth, but apparently not reaching the horizon. The meteor burst with a momentary increase of light, and ‘the fragments remained visible for about three seconds. No sound of an explosion was heerd after the meteor’s disappearance. The following account of some bright meteors visible on the same evening * © Nature,’ September 14, 1871. OBSERVATIONS OF LUMINOUS METEORS, 75 at Bristol was received from Mr. William F. Denning :—“ On September 4 I noticed several shooting-stars that were quite conspicuous. At 9" 40™ one passed slowly down from the N.E. to the north horizon. It was of globular form, and seemed to leave sparks in its flight. No train of light marked its path. This was the most brilliant one that I saw, and was equal, I imagine, to a star of the first magnitude.” On the 10th of September, 1871, at 7" 4™ p.u., a very brilliant meteor was also seen, while the daylight was yet too strong for any stars to be visible, by Mr. 8. J. Johnson, at Upton Helions, near Crediton, in Devonshire, and by several other persons in that vicinity. It described, in about five seconds, a course of 15°, from an altitude of about 25° to an altitude of about 10° above the south horizon. A large meteor is stated, in the ‘ Madras Times,’ to have been observed at Trevyandrum, in India, on the night of the 21st of October, 1871, which crossed the sky from the north, with rapid speed, in about four seconds, moving at an altitude of 35° or 40°*, Some accounts of other bright meteors, noticed towards the end of last year, will be found described in the accompanying general list of such observations. 1872, Feb. 7, about 9" 40™ p.m.—A second meteor of great brilliancy was seen by Mr. Joseph Lawson, near Brancepeth, Durham, on this evening, of which he communicated the following description :— The meteor first appeared above and to the right of y Cassiopeie, whence it described in about two seconds a downward course of about 30° towards the west, directed nearly from Polaris. It appeared small at first, but in- ereased steadily until the apparent width of the head was about 30’ of are, its uniform expansion strongly conveying the impression of a gradual approach Ursa- e é asor Maj iy ry 6 Cassiopeia : e i Polaris ; 3 @ dea Pris Salas So yoo U geet 3 eZ Position of a meteor’s path among the stars, and its apparent sg gete approach towards the observer, near Brancepeth, Durham.—Feb. 7th, 1872. towards the observer’s place. As it advanced the head became pent-atnlpied intensely white, with a border of purple light, and it finally burst into several fragments, which appeared as very white ‘sparks, advancing further upon the meteor’s course, and speedily becoming red. The fragments disappeared from view behind the smoke of a neighbouring colliery, the noise of whose engines, close at hand, prevented the sound of a report, if any followed the meteor’s explosion, from being heard. 1872, March 4, 7° 45" p.w—A bright meteor seen at many places in * © Nature,’ December 28, 1871, = a2 76 : REPORT—1872, -- England was thus described by Mr. T. Perkins, who observed it at Durham. The Durham Cathedral clock had just finished chiming the hour of a quarter to eight when the meteor appeared. The apparent size of the nucleus was much larger and its light was much brighter than that of the planet Venus, and it appeared of a brilliant greenish-blue colour. It described a course of Pleiades e Alde- eis baran Se @ Ov 2 2 7 ¢ Orion Ee, ° ° See e : about 20°, with slow motion downwards, in about 2 seconds, and vanished suddenly (if it was not hidden by the branches of some neighbouring trees) at an apparent altitude of about 12° or 15° (as measured afterwards by the elevation of the trees) from the horizon. Its point of disappearance was about 8° or 10° below a point between the stars (3 and x Orionis. Its path was slightly curved, as shown in the figure, and directed, in the latter portion of its flight, very nearly from the Pleiades. Mr. 8. H. Miller observed the appearance of the meteor near Wisbeach in Cambridgeshire, its light causing him to turn round and to note it in the last portion of its flight. In apparent size it appeared to be about one-third of the apparent diameter of the moon, perfectly white, like a drop of liquid silver, falling in the west, where it descended to the horizon. At Northwich, in Cheshire, it appeared to cast as much light as the moon shining brightly in its first quarter. It shot from the direction of the Hyades, near Aldebaran, and disappeared close to Orion’s belt (Manchester ‘Examiner and Times’). It also attracted attention at Bowdon near Man- chester, where it was observed in the south-west, descending towards the S.S.E. horizon. It was at first accompanied by a reddish train, which changed to blue and left some sparks, when the meteor, with a dip southwards, sud- denly disappeared. As seen at Bolton, near this point, by Mr. A. Greg, it appeared facing him (and to another observer, “low down in the sky” before him) as he looked towards the south; and it disappeared in a large and bril- liant flash while passing over the belt of Orion. 1872, March 8, 9" 5".—The most brilliant meteor recorded during the year, and one of great interest from the southern character and much further westerly situation of its radiant-point than that of any meteor-system hitherto recognized during the period of that month, was observed by the assistant at Lord Rosse’s Observatory at Birr Castle, in Ireland, and was thus described j : : | OBSERVATIONS OF LUMINOUS METEORS. 77 in his note of its appearance communicated to ‘ Nature’ of the 14th of March last by Lord Rosse :— Observed an intensely brilliant meteor. It was first seen in the region of Lepus, whence it moved with a slow and steady motion across the heavens to the §.E. horizon, where it gradually disappeared in a bank of cloud at about 9" 5™ 19° Greenwich mean time, having occupied 7 or 8 seconds in moving over 50° of a great circle. The time given may be a few seconds wrong, as it was noted by an ordinary watch. The head was intensely bril- liant, of a bluish-white colour, and lighted up the whole sky. “Tts brightness was maintained during its entire visibility, and may have been as great as the moon at quadrature. Apparent diameter of the head 42’. It was followed by a very narrow tail about 3° in length, and of a reddish hue. It did not leave any phosphorescent train behind it; but at the latter part of its course it threw out some reddish luminous masses that gradually faded away. Its apparent course was in a great circle through § Canis Ma- joris to a point near the S.E. horizon in azimuth S. 283° E., and altitude 83°. For 3 Canis Majoris the azimuth was 8. 20° 52"4 W., and altitude 16° 43"3. —Observatory, Birr Castle, March 8th, 1872.” It is to be regretted that a meteor of such unusual splendour and magni- tude, which must (if clouds permitted) have been widely visible over the south of Ireland, and in the west and south-west parts of England, has not received any public or private notice which has hitherto come to the know- ledge of the Committee, nor any apparent recognition from observers; while, if the important astronomical interest that attaches to its appearance is rightly understood, the great advantage of their investigation, if such have been pre- served, it may yet be hoped, will prevail upon observers to communicate them to the Committee. 1872, April 12, 4" 36™ p.w.—A fireball, not less brilliant, but, on account of its appearing in the daytime, probably less conspicuous than the preceding meteor, was seen on the afternoon of the above day by Mr. Whipple, at the Kew Observatory, by whom the following observations of its appearance were recorded * ;— “Yesterday afternoon, whilst standing on the lawn of the observatory, with my back to the sun, which was brightly shining, I saw a splendid meteor fall in the south-east. The sky at the time was of an intense blue, and cloudless, with the exception of a few cirri in the north and north-west, and the meteor, as seen against it, presented the appearance of-polished silver. The flight of the meteor was almost vertical, at an altitude of about 30°; its extent was about 10°, and the tail, which seemed to hang in the air and fade away like the tail of a rocket, was, at the instant of:explosion, probably 3° in length. There was no report accompanying its disruption, or it would certainly have been heard, the neighbourhood being very still at'the time. Immediately on its disappearance I looked at my watch; it was 4" 36™ p.m., Greenwich mean time. Had the fall occurred after dark, I have no doubt but that the meteor would have exhibited a magnificent spectacle ; for its brilliancy far exceeded that of the moon as seen by daylight.” / 1871, December 6th, 8" 14™ p.m., or 8" 15™ p.w.—A meteor of great bril- liancy was recorded at the former hour at Birmingham by Mr. Wood, and at the latter hour at Beeston Observatory, near Nottingham, by Mr. Lowe. The descriptions of these meteors, which are included in the following general list, differ in some important physical respects, which might almost lead to an independent conclusion that two different meteors were observed. The meteor * Nature,’ April 18, 1872. 78 REPORT—1872., seen by Mr. Wood at Birmingham was deep blue; its nucleus disappeared without apparent expansion or explosion, and left a very slight, evanescent streak upon its course. The meteor observed by Mr. Lowe at Beeston was distinctly red; it burst with a flash, and left a very enduring streak of red points upon its course. With these essential differences of character (and even with the short interval of only one minute between the times of their observations), the identity of the meteor seen at Beeston with that observed by himself is regarded by Mr. Wood as not sufficiently established, or as being at least open to question, in the absence of further observation. The recorded positions of the meteors’ paths are, moreover, so close to each other, that although they present a small displacement in the right direction to be produced by the great distance (about 45 miles) between the observers’ places at Beeston and Birmingham, yet the unusual height of 360 miles above the earth at first appearance, and of 240 miles at disappearance, which their comparison together would suppose, must be regarded as requiring a proof from further observations, of which none have hitherto been received by the Committee. III. Aroxrres, The following accounts of two aérolites which fell last year are extracted from the scientific journals in which their eek aah have recently ap- peared. 1, Searsmont, Maine, U.S., 1871, May 21, 8" a.m. (local time).—Professor Shephard, of Amherst College, Massachusetts, has published some particulars respecting the meteoric stone which fell at Searsmont, Maine, U.S., on May 21st. About 8 a.m. there was heard an explosion, like the report of a heayy gun, followed by a rushing sound resembling the escape of steam from a boiler. The stone fell in a field, and a lady who was in a house close by saw the earth scattered in all directions as it entered the ground. The hole which it made was soon found, and on digging down the fragments were found still quite hot, the outside surfaces showing plainly the effects of melting heat. The largest piece weighed two pounds, and the fragments altogether twelve pounds, They emitted an odour like that of flints when rubbed violently together. The hole made by the falling body was two feet in depth, the soil being a hard coarse gravel; but the fracture of the stone was obviously occasioned by its striking against three large pebbles, each about four pounds in weight. Professor Shephard obtained and examined the largest fragment of the aérolite. Fully one half of its surface was coated with the original crust, and the shape would seem to denote that the perfect mass had been of an oval, subconical figure with a flattish base, so as on the whole to have approached the shape of the famous Duralla stone now in the British Museum. Among the constituent elements were found meteoric iron, peroxide of iron, chladnite, troilite, together with a single blackish mass which Professor Shephard considered was in all probability a plumbaginous aggregate. The following notice of its composition has also recently ap- peared :— .. “This meteoric stone has been examined by Dr. Lawrence Smith (Silliman’s “American Journal of Science,’ September 1871, p. 200). He finds it resemble very closely the Mauerkirchen stone that fell in 1768, the crusts correspond- ing quite closely both in thickness and appearance; the Mauerkirchen stone, however, has not well-marked globules like that of Searsmont, and in thig respect it corresponds more nearly tothe Aussun aérolite, Its specific gravity was 3°701, and its composition is— OBSERVATIONS OF LUMINOUS METEORS, 79 SPAT OU AUOW o v.50s + calc rhnne 100iden MR one yt nee 14:63 Magnetic PyTites oo.) se ccctcenererercuyreerenes 3:06 Bar Titty ore ih foila pus duces dase sh gibt aisy satiate! tie tuare isan 43-04 Bronzite, a hornblende with a little albite or ortho- clase, and chrome Iron .,seepeeereeenes Spats} 39-27 100-00 With the bronzite there may also be some enstatite, which would be con- founded with the former if existing in the stone.” 2. Montereau (Seine et Marne), France, November 1871,—“ It is stated that an aérolite weighing 127 lbs. fell lately near Montereau (Seine et Marne), in France. It appears to have come from the east, and burst with a loud explosion, giving a bright blue light, It is of an irregular spheroid shape, and black, and is to be sent to the Academy of Sciences,”—~‘ Nature,’ Novem- ber 30th, 1871, TY. Mererorrc SHowers. In the prosecution of a system of observations on the annual meteor- showers of the past year, proposed to engage the constant attention of the Committee since their last Report, a more than usually abundant series of successful observations were made, exhibiting with greater completeness than in previous years the general character of the displays, which have presented themselves with more than ordinary prominency on each of the annual shower-meteor dates. . A first description of the observations collected at the several British Asso- ciation Stations qn the nights of the 9th to the 12th of August last is con- tained in the Quarterly Journal of the Meteorological Society for the 15th of November, 1871, where the numbers of meteors mapped at the different stations, and their rate of frequency at certain places where their numbers were counted in successive hours and half-hours, were for the most part fully stated. The following are some additional observations relating especially to this latter point, and to the general characters of the August shower in 1871, as they were recorded by the different observers, The numbers seen per hour by Mr. Wood at Birmingham were, on the night of the 9th twelve, on the 10th twenty-four, and on the 11th sixteen. The meteors came in groups, with lulls; they were mostly small, and with a much larger proportion than usual of orange-coloured and train-bearing meteors, In the watch kept by Captain Maclear at the Royal Nayal College at Portsmouth on the night of the 10th, the sky was throughout clear or over- spread with such a slight haze as only occasionally to dim the faintest stars ; and all the brightest meteors visible were noted between 11 o’clock p.m. and 2 o’clock a.m. from a favourable point of view upon the College roof, where a number of the brightest meteors visible between 11" 45™ and 12" 45™ was also added to the list by Lieutenant Mathias, whose attention was di- rected towards a different quarter of the sky; and the number of meteors visible in a somewhat less favourable position between 10" and 11" p.m. was also counted alone by Captain Maclear. Deducting one quarter of the meteors seen between 11" 45™ and 12% 45™ as having been observed by Lieut. Mathias, the remaining numbers of bright meteors seen by Captain Maclear alone in the successive half-hours ending, during the night of Aug. 10th, at 10°30", 11", 11"30™, 12%, 12°30", 13", 13"30™, 14%, Total were) 6% 10k" 1@ = 12) Qh BBbhn 34 | > BBs 147, showing an increase in the rate of frequency until the end of the watch. 80 REPoRT—1872. Besides those noted, many smaller meteors passed unrecorded, about two thirds of the meteors counted being as bright as first, and some of the rest as bright as second-magnitude stars. But few meteors were visible on the night of the 9th; and twelve were seen between 9° and 10" p.m. on the 11th. Between 10” and 11" p.m. on the 11th no shooting-star was visible, although the sky was then as clear as it had been during the previous hour, or on the night of the 10th. A bright meteor shot downwards through Corona soon after 10" 30™, and a remarkably large one close to Saturn soon after 10" 45™ p.m. on the 10th. The latter meteor was pear-shaped; it lighted up the objects round the observer, and burst at the end of its course like a shell. This meteor was also seen at Cardiff, and was described, in a communi- cation to Mr. Glaisher on the meteors of that evening by Mr. G. C. Thompson, as follows :—‘‘ Aug. 10th, 10" 51™ p.w. Meteor equal to or larger than Venus ; from direction of a,, a, Capricorni, downwards towards the west (right hand), ‘inclined about 60° to the horizon. Beautiful light-green hue. Near the end of its course it seemed to divide into several fragments, or a small cloud of sparks.” It was also visible at Greenwich, where the following notes of its appearance were recorded by Mr. Glaisher’s staff of observers at the Royal Observatory :—“ Aug. 10th, 10" 51™ 15° pw. Brighter than Jupiter; pale green; duration of flight 0-7 second; length of course 5°: left a fine train. Meteor pear-shaped; from 12° below, and to right of Antares, fell perpendicularly.” At Hawkhurst a broad red flash, like that of lightning, was visible in the sky at 10" 50™ p.m.; but the meteor itself was not seen. It was, however, well seen in the neighbourhood of Hawkhurst, and a pretty accurate measurement of its apparent path by objects near which it appeared to pass was there obtained. It fell nearly vertically from about 20° to about 3° or 4° above the horizon, 60° W. from magnetic south, with no great speed ; and it appeared to burst, with sparks, when at its brightest. At 11" 2™, Paris time, corresponding within afew minutes with the time of this observation, a meteor of twice the brilliancy of Venus, of strong whitish light, like an electric spark, was also seen in the south by the observers of M. Le Verrier’s staff at St. Lo, on the French coast of the English Channel, and at Angers on the Loire. Of the other bright meteors seen at Portsmouth on the night of the 10th, one descended towards the east, and burst at disappearance, at about 12" 45™; and one passed across Polaris at 12" 55™. At about 1° 30™ a bright green meteor appeared in the §.8.E., at an altitude of about 10°, moving towards the 8.8.W. Shortly afterwards a very bright one passed across Pegasus towards the 8.W., with an explosion at disappearance. One of the last two meteors may not impossibly be identical with a fireball ob- served by the observers of M. Le Verrier’s staff at Trémont at 1" 32™ 49° (Paris time) on the same night, which passed from R.A. 235°, N.P.D. 29°, to R.A, 200 5s Ne os and burst at disappearance with a strong red light, leaving a luminous streak upon its course that was visible for 33 seconds. On each evening of the shower the numbers of the meteors were also noted, under favourable conditions of the sky, by Mr. W. F. Denning, at Bristol, with the following results :— Meteors. Meteors. Aap 911" BE* 16012 7 Aug. 11. .10" 35™ to 108 50™ 18 Pe S22 to 13" i pee ei to 12» 29 2 OF ailiay to 14 8 ell coe to DOSS eG 3 Oe fowls? 21 ey Meret bce is iro 12 SN 15s ay ORR UO to 11 17 ell ol OO atonlas 23 ae LO to 12° 27 il es) to 13" 15™ di POW IS. to TASH" ORY 11.13" 15" to 13" 30" 14 OBSERVATIONS OF LUMINOUS METEORS. 81 Attention was principally directed to the northern sky, and many meteors doubtless escaped observation. Most of those observed were especially small ones; those seen on the 9th were nearly all minute and scarcely dis- cernible. Several brilliant ones were seen, however. At 12% 23" on August 10, a meteor of great lustre, and star-like in appearance, diverged from Perseus towards the horizon. It was of a blue colour, and left a lumi- nous streak which was visible for about four seconds. At 10" 44™ on August 11, another brilliant one, about as bright as Venus, was visible in Ursa Minor, and the train of light which it left was visible for a few seconds. It was, however, at 12" 50™ on the latter date that the most brilliant meteor was seen. It passed between the fourth-magnitude stars e and £ Cygni, and soon afterwards disappeared, leaving a train of light which endured for about seven seconds, This one, like the great majority of those observed, radiated from or nearly from the small star B Camelopardi. The first of these bright meteors corresponds with an observation at Cardiff, contained in the description of the star-shower on the 10th of August communicated to Mr. Glaisher by Mr. G. C. Thompson :—“ August 11, 12° 22™ 4.4.—A meteor, as bright as Venus, passing downwards between a and Aurigz, from the direction of the sword-handle in Perseus. Fine purple colour ; leaving a portion of phosphorescent train visible for about half a minute, which had, I think, a lateral drifting motion in the direction of 8 Aurige.” No sound followed the explosion of any of these meteors. Mr. Denning adds the following list of observations of the same shower by Mr. Edmund Neison in London, who was assisted in his watch for the meteors by two friends, and who recorded the numbers visible on successive nights, Meteors observed in August 1871. Bright| Total | No. Date. Time, me- | num-| per Remarks, teors. | ber. | hour. h m hm August 6...... 9 58 to 10 47 6 15 18 | Two extremely brilliant. (49™) htt td j.5 5 8 58 to 10 35 17 43 27 =| Four extremely brilliant. (14 37m) pee ate. 9 45 to 10 18 11 29 53 | Two extremely brilliant. (33™) :. Dee cas 9 5tol03 21 62 43 | Five very brilliant. jh 96m - OR 10 7 to 10 58 3l 90 | 106 | Four very brilliant. (51) gl eerree Cloudy ; clear but it 2 ... | One very bright. for 5™ Bee LD) bate 9 55tol10 26 10 20 39 | Three very bright. (31) cael ee 9 Oto 9 56 10 25 27 | Two very brilliant. (56™) Totals ........ Gh 48m “107 | 286 The total number of meteors observable was, without doubt, over 500, as only about one half of the sky was kept under view. The following par- ticulars were recorded of some of the most brilliant meteors which came under observation. 82 REPORT—1872. Date. * Time. Remarks. hm =.58 nf? August 6 ..,... 9 58 0 | From a Cassiopeie to a Andromedex. - Very brilliant blue meteor, leaving a long streak. ” Gaincre: 10 40 ©|A very bright meteor traversed the centre of Ursa Major. ” Tia winwes 10 15 0 | From near a Herculis to Libra. Left a bright yellow train. * Tf cones 10 27 0 | From B Ophiuchi to Saturn. - lh Weausts 10 35 80 | From B Pegasi to a Aquarii. 4 5), 9 45 0 | From Cassiopeia to Cygnus. Left a bright streak. ¥ oS . 10 7 0 | From a Lyre (Vega) to Sagittarius. Left a long train. 5 Opene. 7 9 50 .0 | From Cassiopeia to a Lyre. 7 9 ......, 9 52 O | From Cassiopeia to Cygnus. aS ORD ts i 10 12 0 | From Lyra to Pegasus, a D dens 10 17 0 | From Cassiopeia to Delphinus, leaving a long train, n eae 5 10 30 0 | From Cassiopeia to y Pegasi. Left a long train. re OI, A 10 5 0 /| From 6 Cygni to a Aquile. Yellow. ei LO as 10 40 0 | From Draco to Serpens. Left a long train, oot 10d Ol, Peiiee ok 10 45 0 | From Lyra to Ophiuchus. Left a long yellow train. ~ eee WY Sa ee 10 50 0 | From Cassiopeia to Lyra. Left a long, pale-blue train. pete LO eee se. 10 55 0 | From Cassiopeia to Cepheus. Left a long train, pte PUBO e! 10 10 0} From Aquila to Sagittarius. cM STS ra 10 3. 0 | Along the Milky Way to Saturn. sat. ed! aastie 10 7 O | Towards the south, near Saturn. Pome | ageeneee 10 16 0 | From 7 Pegasi to Andromeda. Left a streak, PO is ehae | 9 33 0| From Cepheus to Perseus. Left a brilliant train, 4g lla Sarnia 9 56 O | From Capricornus to Sagittarius. Fast and brilliant. At Hawkhurst the appearance of the last meteor but one of this list, on the 13th, was recorded at 9" 32", slowly and steadily increasing to a bolide of about the brightness of Venus, of nearly white or pale yellow colour, tapering behind to a narrow train, which marked its track for a few seconds. It first appeared close to h Urse Majoris, and fell perpen- dicularly, about 12° along a line drawn from » Draconis, or from between the stars e and £ Urse Minoris, towards the horizon. The meteor ap- peared in full view, and the point of first appearance and the length and direction of its flight (apparently from Draco) were very exactly noted. A detailed description of the various meteors of the shower recorded at the Radcliffe Observatory, at Oxford, was also obligingly communicated to the Committee by Mr. Main. The meteors were chiefly observed by Mr. Lucas, who was occasionally assisted by Mr. Keating; and the following Table shows the number of the meteors which were noted on the successive nights. No. re- Date. Time. Plo. of feanied Remarks. meteors.| per hour. hm bm : Aug. 7...|9 40t013 0} 10 3 | Watch kept until 13" 30™; no meteors as | (3® 20”) bright as 1st-mag. stars observed. FP 8... 9 30 to 14 49 47 9 | Watch until 15". Motion of the meteors (5" 19™) mostly very rapid. Eleven meteors= Ist-mag. stars. Py 9...;9 11 to 14 57 57 10 | Watched from 8» to 15" 30™. Seven me- (5 46™) teors = Ist-mag. stars. » 10...)9 8tol4 44] 100 18 | Watched from 84 30™ to 155. Four me- (5' 36™) teors brighter than the fixed stars. Seven- teen meteors = Ist-mag. stars. to15 9} 102 17 | Watched from 8" 30™ to 15510™, Three h Sm) meteors brighter than the fixed stars. Nineteen meteors = 1st-mag. stars. Totals ml 26h gm 316 OBSERVATIONS OF LUMINOUS METEORS, 83 The following particulars of some of the most remarkable meteors are con- tained in the list of observations, of which a full description will be included in the forthcoming printed volume of the Radcliffe Observations. Date. | rime, | h August 8...| 12 Beas ise ace 11 Ly 22: 1s Dees 1 eee 13 «| 10 14 m 30 40 10 Remarks. Meteor=1st-mag. +; white; duration one second. Shot from x Draconis to a Corone. Curved path and long train. Meteor=1st-mag. +; white; duration two or three seconds. Shot past a Lyre northwards, leaving a streak. Mr. Keating saw a meteor pass through the field of the Transit- circle while looking for a star near the south horizon. Meteor =2nd-mag. «; duration one and a half second. From @ Cassiopeix to 6 Cygni, Meteor with a long course and streak, Meteor=1st-mag. *; duration one anda half second. Shot from a Delphini past 6 Aquile, leaving a streak. Two meteors=2nd-mag. *s appeared in quick succession, with an interval of about one second between them, passing on yearly the same course from a point near a Piscium towards n Ceti. Meteor=2nd-mag. x; white; duration two seconds. Passed from x Draconis, just under Polaris, —*. This meteor had the slowest motion of any observed in this night’s watch. Brighter than a lst-mag. *; red. Shot from 6 Pegasi to a point near 8 Aquarii. This meteor rapidly followed two other meteors equal to 2nd and Ist-mag. xs in Bootes, and directed from 8 Andromedx to y Pegasi. A flash of red light from the south was visible in the sky, re- sembling lightning. [Meteoric. See above.] As bright as Jupiter; duration two seconds. From a point under y Urs Majoris to the north horizon. Brighter than a lst-mag. x; yellow. Passed from y Ca- melopardit to a Urs Majoris, leaving a brilliant train, about 15’ in width, visible for about fifteen seconds, just under Polaris, after the meteor had disappeared. Certainly the most brilliant train I have ever seen. A streamer-look- ing appearance was visible in the place for half an hour, and was recognized by Mr. Keating at 13" 0™. [The meteor was also seen at Leamington, and, as will shortly be described, by Mr. Greg, at Manchester. ] Meteor=Ist-mag. x; white; duration one second. Passed from a point near y Cygni to 7 Pegasi. [From radiant in Cygnus.] At 14" 13™ two meteors=4th-mag. xs, appeared at the same instant moving in parallel paths between Band n, and between a and y, across the constellation Pegasus. Brighter than a 1st-mag. x; duration one and a half second. Shot from 7 Persei, increasing in brightness, and changing from red to blue, and leaving a streak, until it burst over y Andromede. Meteor=Ist-mag. x; duration one second. Passed from a Cygni to a point south of a Lyre, leaving a bright train. This train was in two parallel lines, which slowly joined together sideways, and then disappeared (Mr. Keating). Two fourth-magnitude meteors, with an interval of two seconds between them, shot from Z Aquarii to d Capricorni, and from a Aquarii to B Aquarii. ; As bright as Jupiter. From a point between 6 and ¢ Draconis to halfway between a Coronx and a Ophiuchi. Left a train visible for five or six seconds. (The beginning of the meteor’s course not well seen.) ' f As bright as Jupiter; yellow. From cz Tauri to a little below Aldebaran. Left a streak. Two second and fourth-magnitude meteors appeared imme- diately following each other from y Urs Minoris to between » and @ Draconis, and from a point just over / Urs Majoris, descending vertically. t+ Known in maps of Bode’s Constellations as the star 7 Custodis, 84: REPORT—1872. The following observations of the shower by Mr. R. P. Greg, at Man- chester, on the night of the 10th, and at Bolton on the nights of the 11th and 12th, describe the unusual appearance of one of the most remarkable meteors recorded in the above list:—“The number of the meteors was larger than usual, though not remarkably so. On the 10th and 11th, between 10" 30™ and 12", I did not perceive much difference in the horary numbers: perhaps four or five in a minute for two observers; coming sometimes four or five nearly together, and then several minutes passing without any being visible. On the evening of the 12th there was a great falling off, not only in the numbers, but also in the size and flashing train peculiar to the Perseids. At about 9" 30™ p.w. on the 10th, before I looked out, I heard that a splendid meteor was seen here. “At 12" 31”, on the night of the 10-11th of August, a very remarkable meteor appeared in the 8.E., which I hope may have been doubly observed, although it was visible after the time appointed for the simultaneous watch. It commenced close to 8 Andromede, moving nearly on a line from n Persei to a point a little beyond the star y Pegasi, which it almost crossed, describing a course of 10° or 12° in about two seconds. The nucleus had a sensible disk of about 2’ in diameter, and, together with the train, showed prismatic colours. The train lasted twenty or thirty seconds, and soon. assumed a serpentine appearance. It was one of the most beautiful meteors Thaveseen. About four or five seconds after it had disappeared, it broke out again five or six degrees further on, near \ Piscium, moving exactly in the same direction, apparently the same meteor over again, about half its former size, but with the same colours, and leaving a bright streak on this part of its course for about three seconds. What appears most unaccountable was that it broke out again three or four seconds, at least, after it should have done, had it been the same meteor continuing onwards at the same velocity. It seemed, instead, to be another meteor, although it must have been the same; but how its speed could be so checked after it first ceased to be visible, and it could then go on at the same speed as before, I do not know.” The results of the regular observations made at the Royal Observatory at Greenwich, by Mr. Glaisher’s staff of observers, are, in point of numbers and of the brightness of the meteors seen, very similar to those obtained at Oxford, the watch on the nights of the 10th and 11th being kept for about six hours and four and a half hours, and during from two to three hours on each of the remaining nights. The total number of meteors mapped, by the parties of from one to four observers who watched during a space of about 25" 50™ on the different nights was 470; and the ayerage number per hour, with that of the meteors equal to or brighter than first-magnitude stars alone, recorded on each night is shown in the following Table :— Date; 18d 30™, when it was obscured by the rising moon. A similar faint appearance was observed by Professor Herschel, at Glasgow, on the evening of the 7th. 86 RETORT—1872, meteors were counted between 9" 30™ and midnight, of which forty-six fell during the last hour. The courses of fifty-six bright meteors were mapped during a watch of about eight hours on the nights of the 9th, 10th, and 11th, with an average hourly rate of appearance, for one observer, of three bright meteors on the 9th, nine on the 10th, and ten on the 11th, all of them directed from Perseus. The Perseids were of all magnitudes, but the greater number of bright ones (in proportion to the number visible) made their appearance on the 11th, They presented the appearances com- mon to the meteors of this radiant; and some of them left brilliant streaks of blue light, which expanded after the o << disappearance of the nucleus, fading gradually from the ends towards the centre. In several instances I noticed that the nucleus was apparently separate from the train, the brighter ones reminding me very much of the corresponding shower of 1863.” On the nights of the 10th and 11th the sky was overcast at Edinburgh and Glasgow; but several bright meteors were seen at Glasgow on the nights of the 7th, 8th, and 9th by Professor Herschel, one of which shot with a flash overhead at about 12" 48™ a.m. on the 9th, resembling faint lightning. At Edinburgh on the 9th, and at Sunderland on the 11th and 12th, the paths of fifteen Perseids were also mapped by Mr. T. W. Backhouse, although the sky was obscured at Sunderland by thick fog and haze. At Knocklong in Ireland a good view of the shower was obtained by Mr. Jeremiah Henly, whose description of its appearance was communicated to the Committee by Mr. W. F. Denning :— Although I did not reckon the actual number visible, I considered that more meteors appeared on the 11th than on the 10th. On the 11th, in about three hours, I witnessed thirty- three of remarkable brilliancy, while on the 10th, in the same space of time, only twenty-seven of a similar character were visible; but the smaller meteors I did not reckon on either night.” Mr. Denning also regarded the shower at Bristol as at least as intense on the second as on the first night of its appearance, and thus describes the principal characters of the meteors seen:—“ The majority of the meteors were accompanied with trains, which, however, disappeared immediately on the extinction of the head. Most of those seen were white, but several appeared blue, and some of a yellow colour. No sound was heard after the explosion of any of them. The meteors were most numerous on the night of the 11th-12th; and the same was the case in the year 1869, according to my own observations.” At Hawkhurst the paths of 107 bright meteors were recorded with more or less detail by one observer, during a watch of about ten hours, on the nights of the 9th-13th of August, lasting about three hours (until shortly after midnight) on each of the first three nights, and for a shorter time on the other two. The average hourly numbers noted on the former nights were six bright meteors on the 9th, sixteen on the 10th, and eleven of similar character on the 11th. Three brilliant meteors appeared on the night of the 12th, and one on the night of the 13th, among ten bright ones recorded in an hour on the former, and seven in the same time on the latter night. Of these, the first (already stated to have been seen at the Royal Observatory, Greenwich) appeared at 10" 46™ 30° p.m., with a sensible disk and apparently fully as bright as Venus, of dazzling bluish-white light, crossing (3 Ursee Minoris from a point about half a degree below Polaris, be- ginning at R. A. 40°, N. Decl. 894°, and ending at R. A. 225°, N. Decl. 75°, It left a bright streak which remained visible, on its whole course for about OBSERVATIONS OF LUMINOUS METEORS. 87 three seconds. At the Royal Observatory, Greenwich, the meteor, of pale- green colour, leaving a bright streak visible for fourteen seconds, moved in about two seconds from. Cassiopeis across 3 Cephei, almost to a Lyre. The other two bright meteors seen at Hawkhurst on the 12th were scarcely inferior in brightness to this one. That which appeared at 11" 16™ passed from 7 Pegasi to a point midway between y Piscium and ¢ Aquarii, changing from blue to yellow colour as it increased, and leaving a bright streak for a few seconds on its course. The second was observed at 11" 34™, passing in fully one and a half second over 30° or 40° of are from the star B Andromede, along a line directed from 5 Cassiopeize and inclined about 50° to the horizon. Tt left a bright streak for some seconds on its course, which was broken into two, or had two maxima of brightness at two different points of its length. The apparent paths of these two meteors were :— R. A. N. Decl. R.A. N. Decl, August 12..11"16™> Q. Began at 348°+22°. Ended at 343°+4+ 6° ‘ dame DO gees PR pape ou: 13-4163 The trains of most of the meteors seen at Hawkhurst were bluish and rather faint, except when seen foreshortened. They sometimes distinctly spread out after the star had disappeared, and grew gauze-like. They rarely resembled the golden-yellow dotted lines which have sometimes been seen to mark the track of bright meteors in former August showers. Position of the Radiant-pornt. At Bristol, on the evening of the 10th, Mr. W. F. Denning “ saw several small meteors which, from their various paths, must have been in close proximity to a radiant-point which is undoubtedly situated at R. A. 2" 30™ # (374°), N. Decl. 58° 30’. This is Bp about 34° 8.W. of the sword-handle of Perseus, and between x Persei and B 2p Camelopardi. I saw several small Be: meteors whose paths were extremely Cassio-peia short, that came exactly from the place I have indicated. The annexed aS is a rough delineation of a few of the * meteors’ paths that were observed in € the neighbourhood of this radiant- % point in Camelopardalus. There were many other meteors whose paths were conformable to B Camelopardi; and el there appears no doubt as to this being the radiant-point, or rather the prin- cipal one.” Set London, August 10th.—On this Came/o- evening the radiant-point appeared to pardalus 7 # Q & _ Mr. Crumplen to be for most of the gouey meteors near y Persei; but another S radiant-point higher up in the sky Rk a was quite apparent for some of them. q ‘Tn the case of every meteor, whether . & mapped or counted, I ran my eye back along the track to determine, if possible, the true radiant-point. It 88 REPORT—1872. appeared clear enough to me that there was more than one radiant, or that a somewhat extensive space of the sky would be required if the tracks of all the meteors were to be included in it. I believe, however, that the great majority of the meteors will be found to have diverged from a spot rather higher than the famous cluster in Perseus (33 Hyr), say about 1° above. Meteors from this point have been plentiful each evening, and three quarters of those observed between 11° and 12" on the 10th came from there. I noticed that these followed each other rapidly, and that after a lull for a few minutes, a radiant still higher would manifest itself, as will be indicated by the map. The radiants in Ursa Major, Cygnus, and Pegasus were also active, especially the latter; but with one or two exceptions these meteors were not particularly noted.” From avery full projection of more than 300 meteors seen at York between the 5th and the 12th of August, Mr. J. E. Clark obtained the proportions of the meteors directed from each of the principal radiant-points of the shower in 1871. “The proportion of the Perseids observed was about 85 per cent., from Cygnus 7 per cent., from the radiant below e Pegasi about 43 per cent., from Polaris about 2 per cent., and from an apparent radiant-point in Aquarius about 1 per cent. One meteor was observed in Auriga, appa- rently from a radiant-point near 6 Aurige. “The main radiant on the 10th, as shown by the mapped courses, lay close to m Persei; but very many were directed from a Persei, or even lower still, whilst a large number extended the radiant to x. Besides the central radiant, there seemed to be one or two outlying points from which the tracks appear to diverge. One of these seems to be between @ and y Andromede, and another by ¢ Camelopardi. “Of meteors almost stationary, the best was one seen by Mr. Waller and Mr. Brown just by » Persei on the 8th. I observed some nearly so, near y Persei on the 8th, below y on the 10th, and at y on the 11th, also by v Draconis on the 10th; and Mr. Brown saw one by p Cephei on the 8th.” In a letter in ‘ Nature’ of August 17, 1871, Mr. Clark communicates the numbers of the meteors seen on each night, together with some further par- ticulars regarding the above radiant-points, which are here appended. ‘“‘ Having been engaged during the past week in observations on the August meteors, I thought a few of the results might be interesting to some of your numerous subscribers. My regular observations extended from Sunday night to Friday night; and, as the following Table will show, the weather was, with the exception of one night, as favourable as could reasonably be desired. From over 120 meteors mapped down (out of about 330 seen) it is evident that, the principal radiant-point, or rather line, is a line drawn from a Persei to y Persei, and onwards towards 7. One bright meteor was seen on the 8th, just below » Persei, which did not move more than 4° in a second of time, and left a cloud behind it lasting about two seconds. A remarkable feature was the outlying radiants, as they appeared to be, one of which was situated at or near @ Cassiopei, another near the star c of Camelopardalus. The radiant situated between 6 Cygni and y Draconis is yery well marked; also a radiant near y Cephei (where another almost stationary meteor was observed), and one just below e Pegasi, towards a Aquarii; associated apparently with the last is a radiant near the small lozenge in Delphinus, above a Aquile. “Tn the following list of 312 meteors observed here, 242, or about 77 per cent., were from the Perseus radiant or radiants :— OBSERVATIONS OF LUMINOUS METEORS. 89 “ Meteors seen August 1871, at York. Hours. State of sky. peeeed ates Raise, Proportion. hmhm SETOMCO—HO TOL | HUNG) seoscncceaosst- 6 5 83 see] IO 20-12 O | Hime .........000.0. 34. 28 “82 SeeTO! O-T2, 0.) BING: 5.65.2: -65.s00- 49 30 “61 ..| 10 o-12 © | Fine, till 11°45, then cloudy ... 50 31 *62 .| 10 30-11 30 | Cloudy and hazy . 6 4 6 9 55-12 5 | Few clouds at times, and very slight haze......) 120 106 “88 9 55-125 | Ditto .........,..... 47 38 *80 «Generally two watching, sometimes three, and once or twice but one. For the 10th I had a list of twenty-six others handed me, observed by a friend close at hand, of which nineteen were from Perseus. “J, Epmunp Crarx.” 20 Bootham, York, August 14.” At Birmingham the position of the radiant-point appeared to Mr. Wood to have undergone no change from its apparent place as described in former years. At Manchester on the 10th, and at Bolton on the 11th and 12th, Mr. Greg noted especially the short meteors near the radiant-point in order to deter- mine, if possible, its real place. On the night of the 10th it appeared to be situated about halfway between 7 and y Persei, on the 11th exactly at », and on the 12th about halfway between y and y Persei. In relation to these results Mr. Greg observes :—“ There can, I think, be little doubt, judging from my own observations, that this year the radiant-point was lengthened out on a line between x and y Persei, with the centre precisely at y (or &), that there was a tendency to move with the time from x towards y, and that on the night of the 11th the tendency to accurate radiation was unusually pre- cise. Probably accuracy of radiation is a symptom of a particular shower - being at its maximum intensity, with the individual meteors less scattered than at periods of its minimum display. I saw so very few meteors move near the radiant, either up or down, that I cannot so precisely state the position of the radiant-point in right ascension as in declination.” Among the list of meteors received by the Committee from the observers of the August shower in 1871, the paths of 316 meteors noted on the nights of the 9th, 10th, and 11th of August were sufficiently well indicated to be correctly delineated on suitable star-maps. Of the whole number nine were directed from a radiant-point near the north pole of the heavens, at about R. A. 10°, N. Decl. 82°; fourteen proceeded from a radiant-point in Cygnus, apparently close to 8 Cygni, at about R. A. 293°, N. Decl. 42°; and thirty-three meteors diverged from radiant-points in or near the constellations Pegasus and Aquarius. Of the remaining number a few meteors appeared to be very erratic or sporadic, and about 250 were distinctly members of the shower diverging from the radiant-point in Perseus. The long duration of the shower appearing to offer a favourable opportunity for ascertaining if the _ position of the radiant-point underwent a sensible change during the time of its continuance, the recorded apparent paths of all the Perseids noted during successive intervals of ten minutes on each of the nights of observation were 1872. H 90 REPoRT—1872. projected upon separate maps. A similar projection of the paths of the meteors recorded at the Royal Observatory at Greenwich on the night of the 10th of August was also made upon a separate map for each interval of ten minutes during the hours of observation. With the exception of the period between 9° and 10" p.m. on the 10th among the Greenwich observations, and between 9°45™ and 10" 45™ p.m. on the same evening among those of the British-Association observers, when 40 per cent. of all the meteors mapped diverged very accurately from a centre of radiation at about R. A. 34°, N. Decl. 61° nearly midway between y Persei and « Cassiopeie, and a very marked activity of this radiant-point during the following hours of both those series of observations until midnight on the 10th, no tendency to accurate divergence from a single radiant-point during any sustained period was obser- vable during the continuance of the shower. A radiant-point near n Persei, which was also discernible among the British-Association observations on each evening of the shower, presented itself most conspicuously in those made at Greenwich on the evening of the 10th, towards midnight, and by the inter- section of its meteor-tracks with others from the more northern radiant, appeared to give rise to a prominent centre of divergence after midnight between y and e Cassiopeize, which may have owed its apparent activity to the simultaneous existence of the former pair. The general radiant-point of the meteoric shower at Greenwich on the night of the 10th was very nearly the principal one already indicated, with a tendency, especially after midnight, of some meteors to come from directions nearer to and to y Persei. All the meteor-tracks noted by the British-Association observers between 9" 36™ and 12"44™ on the 10th having been projected upon a single map with the radiant-point in Perseus near the centre of the projection, a densely crowded region of intersection of the tracks prolonged backwards was found to occupy a roughly triangular space of about 10° in length along each side, having its centre very nearly at the above indicated spot in R. A. 36°, N. Decl. 58°, and its angles in nearly symmetrical positions at points in R. A. 31°, N. Decl. 61°, R. A. 36°, N. Decl. 53°, and R. A. 45°, N. Decl. 59°, as shown by the small circles marked in the accompanying figure. The first of these points cor- responds very closely with the definite radiant-point, which was most conspi- cuous during the early portion of the shower. On the night of the 11th the principal intersection of meteor-tracks recorded at the Royal Observatory, Greenwich, was still close to the latter point, at R. A. 31°, N. Decl. 62°, during the hours of observation from 9 until 13" 30", with subordinate points of intersection at B and D Camelopardi, and between n and P Persei. A projection of all the tracks recorded by the British-Asso- ciation observers between 9" 45™ and 13” on this night having been made on a similar map to that prepared for the observations of the 10th, the principal centre of divergence was found to be placed not far from its position on the previous night, a few degrees northward from y Persei, at R.A. 31°, N. Decl. 58°. A meteor with very short course appearing close to this point marked its position very nearly. The tracks of the remaining meteors were almost evenly distributed round it, within distances which included nearly all the courses of 12° or 15° from its centre. But other apparent centres of radia- tion also presented themselves somewhat definitely near the north and south borders of the radiant-region, in the neighbourhood of ¢ Cassiopeiz and y Persei, at points in R. A. 25°, N. Decl. 63°, and R. A. 42°, N. Decl. 55°, as shown in the figure by the small circles marked @), forming apparent outliers of the central point. a OBSERVATIONS OF LUMINOUS METEORS. 9] On the night of the 9th of August the apparent paths of 38 Perseids re- corded by the British-Association observers between 9° and 12" 50™ appear to have diverged from two definite radiant-points of nearly equal intensity at the extremities of an oval space, extending from » Persei to near e Cassiopeie, through which nearly all the recorded paths prolonged backwards passed. These points were situated in R. A. 29°, N. Decl. 60°, and R. A. 39°, +.55°. w 3 » 8, me) vo Ss XK 8 © I~ or ne S 3 'Q eee S) o ‘> ia at ~ > =: | @ > X The general centre of divergence of the Perscids during the whole period of greatest intensity of the shower on the nights of the 9th—12th of August, 1871, was shown by the combined results of these observations to be a few degrees northwards from the star x Persei, and not far from a point in R. A. 35°, N. Decl. 59°, which is the average place obtained by giving equal weight to all the separate radiant-centres shown iu the figure, of which the positions H 2 92 REPORT—1872. were determined from the observations of the shower communicated to the Committee by the observers for the British Association. The figure represents in plane perspective the apparent paths of all the Perseids noted on the nights of the 9th, 10th, and 11th of August, 1871, whose visible tracks were in the immediate vicinity of the general radian-tregion of the shower. Meteor-showers in October, 1871.—On the night of October 14th, between 115 and 12" p.m., six meteors, as bright or brighter than 1st-magnitude stars, were observed at Hawkhurst in one hour, radiating with considerable accuracy from a point near the head of Aries, and close to the point of first. appearance on this date of the radiant R, in Musca, which appears to contri- bute bright meteors from the direction of this constellation during the prin- cipal meteor-showers of October, November, and December, but from which so many bright meteors.in one hour as those seen at Hawkhurst on the above date form an exceptional display. Another meteor, ike one noted on this date, as bright as Sirius, proceeded from the same radiant-point, passing over- head at Hawkhurst, and leaving a faint streak, at 11° 45™ p.m. on the 19th; and two scarcely less brilliant members of the same meteor-shower appeared, with short courses and slow motion, near the radiant-point on the 21st of October. Three or four bright meteors with swift motion and leaving bright streaks on their tracks, proceeding apparently from circumpolar radiants near A,,,,, and F,, , in Cassiopeia and Auriga, were noted during the same short watch at Hawkhurst which was kept on each of those dates. The sky was overcast with rain and wind on the nights of the 18th and 19th at Hawk- hurst, and at all the other places from which communications were received ; and although occasional openings of the clouds allowed a few stars to be seen at Hawkhurst, where the single bright meteor last noticed was observed, and at Tooting, where Mr. H. W. Jackson kept a watch for them whenever the state of the sky permitted, no other shooting-stars were recorded. But in a mode- rately clear sky, from 7" 45™ until 11" p.m. on the 18th, six meteors of some brightness were mapped at the Royal Observatory, Greenwich, two of which were directed from R,, one from the north pole, and the rest from a radiant- point near A,, ,, in Cassiopeia, or F, , in Auriga. On the night of the 20th the sky remained overcast at the southern stations ; but at Birmingham, Sunderland, and Glasgow a few meteors were visible through fog and haze, which generally obscured all stars less bright than the third magnitude, until nearly midnight, when the sky gradually became more clear. Three small shooting-stars were observed at Glasgow by Mr. R. M‘Clure between 11” and 12" p.m., and two by Mr. Wood at Bir- mingham, as described in his observations on the shower. Between 9 o’clock and midnight on the same ‘evening, four meteors, three of which were directed nearly from R,, and one apparently from the north pole, were observed by Mr. T. W. Backhouse at Sunderland; they were unconformable to the radiant O (Schiaparelli, No. 36, B. A. Report for 1870, p- 98), or to any of the other radiant-points noted by Mr. Backhouse in the morning hours of this and the two following nights. Another bright and unconformable meteor, seen on the same night, was also directed from the north pole; while the twenty-one remaining meteors, seen in the course of about two hours of observation on the mornings of the 21st, 22nd, and 23rd (and all but three on the earlier dates), indicated the return of the October meteors, and presented some contemporaneous radiant-points, of which Mr. Backhouse gives the following description in his remarks on these results of his observations :— “The meteors marked A [twelve meteors noted in about an hour and a ———— SO NT IG se. alle OBSERVATIONS OF LUMINOUS METEORS. 93 half on the mornings of the 21st and 22nd, and another on the morning of the 23rd] in the list belong to Schiaparelli’s Radiant No. 36 *, and those marked C [two meteors noted on the last morning of the watch] to his No. 37+. Those marked B [five meteors seen on the mornings of the first two nights] have a radiant-point in R. A. 113°, N. Decl. 58°; but, owing to the remarkable swiftness of these meteors, this point can be only approxi- mate. I make the radiant-point of A at R. A. 97°, N. Decl. 15°, taking the observations of all three nights. The meteors marked U were unconform- able to all these showers. It will be seen that only one of these appeared in any of the mornings, and no unconformable ones in the evenings. “The hourly rate of frequency of meteors of all.kinds, at that time of morning at which they were most numerous, was on the 20th [morning of the 21st] 19, on the 21st 12, on the 22nd 8.” None of the shooting-stars observed at Hawkhurst, or at the Royal Obser- vatory, Greenwich, on the evenings of the 14th and 18th of October were directed from the radiant-point in Orion; but on the night of the 21st the tracks of eleven meteors from this radiant-point were mapped at Hawkhurst between the hours of 11" 30™ and 13° 30™, and an approximate position of -- the radiant-point was obtained. This appeared to be between the stars y, v Geminorum and » Orionis. A small meteor, almost instanta- neous, near this point described 8 a short path, which appeared eS curved towards Castor and Pol- p Ne Gemint lux, and which lay in the sky like a bent whip(seethe sketch) ® between y Geminorum and ¢ ° Tauri, at about R. A. 90°, N. ® @ @ Decl. 20°. The last meteor of C) fT ‘4 the shower seen at Hawkhurst sd ° on this night was directed from the point C, between Castor and Pollux, regarded by Mr. Bia Backhouse as having furnished e*v a few meteors on the morning E of the 23rd of October, at Sun- e derland, during his observations of this shower. With regard to the appearance of the October meteors at Birmingham, Mr. Wood communicated to the Committee the following results of his obser- vations of the shower in the past and in previous years :— oe Orion Luminous Meteors. Birmingham. Epoch 19th October. W. H. Wood. ' The meteoric shower of the above epoch has not been visible from this Station since 1868; and the following are the unpublished results of those * Brit. Assoc. Report for 1870, p. 98.—Oct. 21. Near y Geminorum, at R. A. 96°, N. Decl. 13°. Apparently identical with the radiant O, near y Orionis, described in previous Reports, of the meteor-shower on October 18-21. t Ibid. Between Castor and Pollux, on October 21-25. About 17° or 18° from Schiaparelli’s position of the former radiant-point. t Connected, apparently, with the radiants F,,, [Report for 1868, p. 403], from the middle of September to the latter end of November, at R. A. 83°, N. Decl. 50°, near a, 8, and 6 Aurige. 94. REPORT— 1872. observations, together with those of the succeeding years, to the present date (1871) :-— Meteoric Shower, October 19, 1868. Centres of radiation and the number Percentage of colours. per cent. from each. Orange or yellow........ = 40 Radiant. per.cont.| Blues nice sc isizes Nene = 40 CD) BAR reticet cle (eilots. oceans = iF Whiter iaih aca sean = 2 BARN NT 101 . 30™ p.m., when it was again obscured. During this interval seven meteors from Gemini, nearly equal to first-magni- tude stars in brightness, were recorded, and their apparent paths were mapped by Mr. R. McClure. The first (described in the above list of large meteors), which diverged like the rest from Gemini, was as bright as Jupiter; and but one meteor of the shower left a persistent streak. A Geminid was also observed at 12" 20™ on the same night, and its apparent course was mapped. The tracks of all these shooting-stars prolonged backwards passed through a small circle about 12° in diameter, whose centre was close to the star e Gemi- norum at a point in R. A. 97°, N. Decl. 28°. Twenty meteors were counted by two observers during the hour of the watch ; but the paths of only the most conspicuous, which diverged from the direction of a radiant-point in Gemini, were recorded upon the map. On the night of the 13th, rain, and a com- pletely overcast state of the sky, prevented any further observations. By projecting all the recorded paths of the Geminids upon a single map, a * This meteor may also possibly have been a “ Geminid,” the direction of its apparent path being very nearly conformable to the position of the radiant-point of the shower in Gemini as observed at its return last year. 100 REPORT—1872. radiant-region of oval form contained between the meridians of R. A. 96° and 112°, and between the parallels of north declination 20° and 40°, would include the directions of 37 of the 45 tracks which are thus drawn. In this area the intersections of the tracks, prolonged backwards, are slightly more concentrated than elsewhere within the radiant-space, at a point in R. A. 104°, N. Deel, 34°, about 4° from @ towards a Geminorum, while the general character of the radiation was diffuse; and the apparent paths of but few meteors were recorded near the radiant-point. Meteor-shower of January 2nd-3rd, 1872.—On these dates a watch was arranged to be kept by observers in different places in England, and at Glasgow from half-past 10 o’clock until midnight ; and a favourable view of the shower was obtained at most of them on the night of the 2nd of January. Towards 11 o’clock a few detached clouds, which had partially obscured the sky in London during the earlier part of the evening of the 2nd of January, disappeared, and the view of the shooting-stars during the re- mainder of the watch until midnight was uninterrupted. In the neighbour- hood of Regent’s Park, Mr. T. Crumplen noted the appearance of nine meteors in this interval, beginning his watch at 102 45™, and recorded the apparent paths of six conformable meteors upon amap. ‘Three of these were as bright as first-magnitude stars. All but one, which appeared ruddy, were white or bluish, not swift in their motion, and two of the brightest left a short streak of light upon their course. The courses of all, prolonged backwards, intersected each other within the space of a small circle 5° or 6° in diameter, having its centre at R. A. 228°, N. Decl. 52°. So quickly did bright meteors succeed each other, that it appeared probable that the shower would continue to be of some brilliancy after midnight. An aurora was visible at the same time in the north. In the south-west part of London, near Eaton Square, the meteors were also watched by Prof. Herschel, between 10" 30™ and midnight, the light of the rising moon, which first appeared at about 11" 30™ v.m., being the only obstruction to their view. The paths of 16 shooting-stars were mapped, of which only one appears to have been unconformable to the usual radiant- point of the shower. It shot on avery short course close to Polaris from the direction of the zenith at 11" 7™, and was not perfectly observed. Four or five smaller meteors may also have passed unrecorded. ix of the meteors mapped were as bright or brighter than 1st-magnitude stars, the brightest ap- pearing white and those of lesser magnitudes of yellow colour. The brightest only of the meteors seen appeared to leave a faint streak of light, visible for less than a second, on its course. This meteor described a path of 35° in two seconds: it was as bright as Sirius during the last half of its course; it appeared at 11" 56", and its appearance was simultaneously observed at Hawkhurst. Of the fifteen conformable meteors, five were erratic members of the shower, their apparent paths, prolonged backwards, passing about 20° on each side of a very definite radiant-point, from which the remaining ten meteors all diverged. A circle of about 6° in diameter, round a central point in R. A. 227°, N. Decl. 49°, would include the intersecting prolonga- tions backwards of the tracks of all the latter meteors. This apparent place of the radiant-point, which was close to that observed by Mr. Crumplen, is also not more than 5° from the position of the radiant-point of the same shower, at R. A. 234°, N. Decl. 51°, as observed in 1864*. A slight increase in the rate of frequency during the watch appears to indicate a * See these Reports for 1864, p. 98. OBSERVATIONS CF LUMINOUS METEORS. 101 growing intensity in the progress of the shower, the numbers of the meteors recorded in the successive half-hours until midnight being 3, 5, and 8. At Tooting, near London, the sky was also very clear on the evening of the 2nd; and Mr. H. W. Jackson noted the appearances of nineteen meteors between 10” and 11” p.m, the tracks of six of which were very accurately laid down upon a map. Hight meteors were observed ; and the paths of two of them were mapped between 11" and 11" 15", and only two meteors were visible in the following 15™ until 11"30™ p.w. The whole number of meteors seen by one observer in 1" 30" was 29. A bright meteor (described in the above list), whose course was exactly conformable to the usual radiant- point of 2nd of January shooting-stars, was also recorded by Mr. Jackson on the night of the 31st of December. Although proceeding generally from the direction of the radiant-region between Bootes and Draco, no definite centre of divergence was distinguishable among the meteor-tracks recorded at Tooting, which appear to have belonged to outlying members of the group; and one of the eight meteors mapped was unconformable to the general radiant-point of the shower. These meteors appeared for the most part white ; they were generally bright, and left faint streaks upon their course, which remained visible upon the track of one of the brightest for about one second. A flash like lightning was observed at 10° 16™ p.m., and two similar flashes were noticed between 10" 16™ and 11" p.m. At the Royal Observatory, Greenwich, the apparent paths and appear- ances of fifteen meteors were registered between 10" 12™ and 11" 17", of which four only were less bright than stars of the first magnitude, in a watch partly kept by one and partly by two observers. They were mostly bluish, but some yellowish white, and described apparent courses of from 10° to 40° in length, in one or two seconds of time. Ten of the meteors recorded in the list left more or less faint persistent streaks of light upon their course. Two or three of the meteors whose apparent paths were thus registered appear to have been unconformable to the general radiant-point, and the tracks of the remainder prolonged backwards present a space of somewhat diffuse radiation in the region about Quadrans and the tail-stars of Ursa Major. The sky was also free from clouds at Hawkhurst on the night of the 2nd, and a watch for the January shower was kept from 11” 20™ until midnight. Fourteen meteors were noted in this interval, and the paths of ten were satis- factorily observed, and were drawn upon a map. All were directed from the neighbourhood of the radiant-point in Quadrans; and the backward pro- longation of their tracks presents a region of somewhat diffuse radiation, extending over an area about 25° in diameter, having an apparent principal centre of intersections at a point in about R. A. 220°, N. Decl. 47°. The meteors seen were principally of the first and second magnitudes, white, shooting across the sky in long courses, with moderately slow speed; and about half of their number left a slight persistent streak of light on the whole or on a part of their course. Several smaller meteors passed unrecorded, and the hourly numbers of the meteors seen was not less than twenty for two observers. At Birmingham the sky was very clear on the night of the 2nd; the courses of fifteen or sixteen meteors were mapped ; and the appearances of many more were noted by Mr. Wood during the hour between 10" 15™ and 11" 15" pa, At 10" 17™ a flash like that of distant lightning (apparently the same as that recorded by Mr. Jackson near London, and if so, probably meteoric) was seen upon the south horizon during an interval of twenty minutes after 10 o’clock, in which no shooting-stars were visible. At 102 REPORT—1872. 10" 20™ a meteor of fourth magnitude was seen, and at 10" 21™a sudden out- burst of several bright varicoloured meteors made its appearance in all parts, four or five shooting-stars being visible in the space of an eye-grasp, so that it was impossible to record the particulars of more than one or two members of this group. Two of them noted by Mr. Wood were brighter than first- magnitude stars, leaving streaks, apparently not conformable to the usual radiant-point of the January meteor-shower, but rather diverging in nearly parallel courses from the radiant A, , in Cassiopeia, or one of them possibly from the radiant NG in that neighbourhood. This burst of shooting- stars gradually subsided, and meteors as bright as first- and second-magnitude stars continued to succeed each other at short intervals until 10” 49™, when intervals of meteoric quiescence, unbroken by the appearance of any shooting- star for 10™, 14™, and 20™, succeeded each other ; and the last meteors seen during the watch were recorded at 10° 59" and 11°13" p.m. Among twelve meteors registered by Mr. Wood during the half hour between 10° 20™ and 10" 50™, two were as bright as, and five brighter than, first-magnitude stars, and five left luminous streaks that remained visible for two or three seconds on their course. In colour they were mostly blue, white, or yellow ; and the duration of their flight was generally from one second to about one second and ahalf. Projected upon a map, the apparent courses appear to diverge from a centre between the last stars in the tail of Ursa Major and a Draconis, several of their visible tracks having been noted in or near the constellation Ursa Major; but many scattered meteors were observed; and in the following remarks on the shower Mr. Wood assigns various radiant-points to the prin- cipal meteors, whose directions he had projected and compared together upon the maps. “* Meteoric shower of January 2nd, 1872.—A fine shower of bright meteors, at the rate of twenty per hour for one observer, radiating in the proportion of 42 per cent. from K, [radiant of the annual shower}, 22 5 from MG, 36 3 distributed over the radiants A, ,, A,,, NG, DG,, KG. “Meteors of slow apparent speed, train-bearing, and varicoloured. The time of maximum, the duration, and intensity of the shower could not be ascertained in consequence of clouds supervening on the succeeding night. The foregoing meteors were probably only a fragment of the shower.” A description of the shower by Mr. J. Morton, at Eccles, near Manchester, was communicated to the Committee by Mr. W. F. Denning. It was first noticed at 8" 40™ p.m. on the 2nd, the sky being then very clear, but after- wards becoming partially obscured by clouds. One bright meteor, leaving a train of sparks, and five smaller ones were seen before 9 o’clock; and eight meteors of some brightness from that time until 10" 23™ p.m. Six of the fourteen meteors noted were as bright as second, and one was as bright as a first-magnitude star. At Glasgow the sky was so hazy on the night of the 2nd, elves 10" 55” and 11> 20" p.m., that Jupiter and the brightest fixed stars only were visible; but during the remainder of a watch from 10" to 12" pw, the sky was cenerally clear, and fourteen meteors were observed in this interval by Mr. R. McClure. ‘The apparent paths of nine of them were drawn upon a map; and of these meteors four were as bright as first-magnitude stars, two were as bright, and the rest fainter than stars of the second-magni- tude. All but one, of reddish colour, which passed in a short course from Ursa Major across the star Pollux, appeared white ; and they described ares of from 5° to 20° in length, in times which varied from a half to a full OBSERVATIONS OF LUMINOUS METEORS. 103 second in duration. Their tracks projected upon a map, although proceeding, as in the foregoing observations, from a general radiant-region near and around the star @ Bootis, presented within that space no well-marked centre of divergence. On the same night, and during the morning of January 3rd, as appears from the following observations at York and Sunderland, the shower con- tinued to be very bright, with occasional lulls and apparently outbreaks of its intensity, until near the approach of daylight. At Sunderland Mr. Backhouse reported that ‘‘ though the night of the 2nd was for the most part very fine, yet at the appointed time the sky was so cloudy that I only watched for a short time, especially as meteors were so scarce. I only saw one at that time; but in the morning I watched for at least twelve minutes in a cloudless but moonlit sky, the radiant-point in Draco being high in the sky, yet I saw no meteor belonging to that system, and only one altogether. ' The evening of the 3rd was fine till about 10" p.m., when it clouded over. I did not sce a single meteor, though I watched for about ten minutes at 6" 30™, and equally long about 9" 15™.” Another considerable outburst of the shower must, however, have occurred shortly before daybreak on the morning of the 8rd, as the brilliancy and rapid succession of the meteors at that time at Street, Somersetshire, attracted a child’s attention, who, as related by Mr. Clark, informed him of some of the particulars of their appearance. ‘The nights, both of the 2nd and 3rd, were so unfavourable as to prevent me from sending you any observations. On the morning of the 3rd, however, I had an account from my nephew, who though but eight years old is intelligent enough to take a good deal of interest in simple scientific things, of several meteors which he had seen, coming rapidly after one another, and evidently somewhat bright.” On the following evening, and night of the 3rd to the 4th of January, the “sky was so completely overcast at all the British-Association stations that no shooting-stars could be observed ; but on that evening a single meteor, as brilliant as Jupiter (as described in the above list), was observed at Green- wich, the direction of whose apparent course was almost exactly directed from the radiant-point K, in Quadrans (Bode, or in the region of Draco between Hercules and Bootes), which distinguishes the annually recurring meteor-shower of the 1st—3rd of January. Meteoric showers of April, 1872.—Some observations of the April star- shower in 1871, not included in last year’s Report, were obtained by Mr. Clark, at York, with a clear view of the sky, from shortly before ten o'clock until midnight on the night of the 19th of April in that year. Six rather bright meteors, with very short courses of only a few degrees in length near the constellation Ursa Major, were mapped, belonging apparently to the meteoric system or group of radiant-points M, in that constellation. One meteor from the direction of Lyra was also seen before eleven o’clock, and six between eleven o’clock and midnight, the sky being equally clear,—the numbers of meteors of all kinds seen in the former hour being six, and in the latter nine. The sky was overcast on the other nights of the shower. The radiant-point M, of Heis’s and Greg’s former list* was marked in * Report for 1864, p. 99. Radiant at R. A. 160°, N. Decl. 51°, enduring from April 16th-30th, apparently identical with M, of Heis’s list for April, at R, A. 155°, N. Decl. 47°, near \ Urse Majoris: now subdivided by Mr. Greg into separate radiant-points, MZ and MGZ, near @ Urs Majoris and Cor Caroli, in March and April; M,Z near y Leonis on the 19th-20th of April; and MG, in the Lynx, near the fore fect of Ursa Major, from the end of April to the beginning of June. (See the Table at the end of this Report.) 104: REPORT— 1872. April last by the appearance of some conspicuously bright meteors, to whose characteristic briliancy Mr. J. E. Clark drew particular attention in the following communication to ‘Nature’ of May 2nd, 1872 (the meteors alluded to by Mr. Clark are described in the foregoing list) :— “ T noticed in your Number of last week the account of a brilliant meteor observed in Cumberland on April 19th. Now I had reported to me a very similar meteor at nearly the same time (about 8" 40™ p.m.), an account of which I forwarded, with the other results of my night’s watch, to Mr. A. 8. Herschel, who would gladly receive any further report of the same; un- fortunately I have not the Number of ‘ Nature’ at hand, and therefore cannot make a personal application to your correspondent. On the same evening, about 11" 7", I myself saw an exceedingly brilliant meteor, which fell to a point just south of Vega. It is curious that both of these came from the radiant situated at about R. A. 155°, N. Decl. 47°, or rather from one of the group of radiants there situated, M, of Heis, 56 and 52 of Schia- parelli. It would be an interesting point of investigation whether the meteors from that radiant-point are of peculiar brightness.” —J. E. Ciarx, April 30th, 1872. The meteor seen by Mr. Clark at York was seen at the same time at Hawkhurst; and the direction of its apparent path there, prolonged back- wards, meets its similarly prolonged track, as observed at York, near y Urs Majoris, very near the position of the radiant-point M,. The bright meteors described in the above list on April 5th and 19th, and May 3rd, appear all to have diverged from the same group of meteor-radiants in Ursa Major. Those recorded on March 26th, April 12th and 22nd, radiated from centres of a group of apparently equally bright meteor-showers, 8 , in the neigh- bourhood of Virgo and Come Berenices. On the evenings of the 12th, 13th, and 14th of April, 1872, Mr. Greg watched at Buntingford, Herts, for an early appearance of the April meteor- ~* showers from the direction of Cerberus or Lyra (QH,, QH,), connected to- gether apparently in one meteor-system making its appearances on the 13th and 19th-20th of April. The former radiant-point was noted from the paths of nine small shooting-stars, seen in about two hours on the morning of the 13th of April, 1864, by Prof. A.S. Herschel at Hawkhurst * ; and no appear- ance of this shower appears to have been again visible in subsequent years. Its radiant position at R. A. 270°, N. Decl. 25°, was yet distinctly marked, the meteors resembling each other even more closely than those of the group from Lyra in their appearance, and moving in swift courses over all parts of the sky from a region of somewhat diffuse radiation, extending to but not exceeding the limits of the small constellation Cerberus (Bode), with an average centre at about the position named. By its close neighbourhood to the well-established radiant-point of the Lyraids at about R. A. 278°, N. Decl. 34°:5 +, it appears to have been an early commencement of that shower, and an integral part of the meteor-system which was first shown by Drs. Weiss and D’Arrest to be apparently connected with the periodic orbit of the Comet I, 1861. Mr. Greg’s watch for the early reappearance of the group on the above date was unsuccessful, two small meteors only being observed from the radiant DG (in the head of Draco), and two meteors radiating from the direction of /3 Herculis, during a very careful watch on each of the above- named nights. Shortly after the end of April last, a communication from Mr. W. F. Den- * Report for 1864, pp. 40 and 98. + See these Reports for 1864, p. 98, and 1868, p. 399. 4, 6,6 OBSERVATIONS OF LUMINOUS METEORS. 105 ning informed the Committee that Mr. Knobel, at Burton-on-Trent, had observed ‘many meteors in April, particularly on April 14th, 1872. They appeared to radiate from a point in Bootes east of ¢ Bootes.” This point, which is yery near to /3 Herculis, was nearly in the direction of the last two meteors seen by Mr. Greg, and in the position of the general radiant Q, ,* of meteors first beginning to be seen about the 23rd of April, but which appears from these ‘observations to present itself close to the same position at least ten days earlier, on about April 12th. (See the Table at the end of this Report. Radiant, No. 51.) The night of the 19th of April, 1872, was generally not unfavourable for observations at most of the British-Association stations. At York, until nearly 11" p.m, the sk’y was nearly overcast; but at that hour the clouds began to disperse, and soon after the beginning of the watch they had finally disappeared. During the succeeding interval between 10" 45™ and 11" 45™ P.M. nine meteors, two of them as bright and two brighter than first-mag- nitude stars, were observed, six being visible in the first and only three meteors, with two or three faint flashes near a Lyre, in the last 45™ of the watch. From 11" to 11" 15™ there seemed to be quite a brisk shower, but after that time their rate of fall diminished considerably. The Lyraids were all noticeably rapid in their flight, their courses varying from 5° to 25° in length, and the duration, even of the longest, scarcely exceeding half a second, They were colourless or white, and there was a noticeable absence of streaks upon their course. ‘Two or three meteors diverged from a radiant, No. 53 of Schiaparelli, in Come Berenices, apparently connected with the radiant 8, ., near the same constellation, in Virgo, of Heis; others from M, ; and five of the nine shooting-stars whose courses were mapped were Lyraids. The brightest of these appeared at 11" 28™, and its apparent course was also noted at Wisbeach and at Hawkhurst. The radiation of the Lyraids was not very exact; but the courses of three, prolonged backwards, intersected each other very nearly at a point in R, A. 280°, N. Decl. 43°, near 7 Lyre. Some further observations on the progress of the shower will shortly be given from Mr. Clark’s report of its appearance. At Buntingford a clear sky prevailed on the 19th, between 11" 15™ and 12" 45", and the apparent paths of seven meteors of first and second mag- nitudes, all of them meteors of the April shower, were drawn upon a map by Mr. Greg. The backward prolongation of their tracks, which were generally not far from the radiant-point, presented a very definite area of intersections 3° or 4° in width, at about R. A. 268°, N. Decl. 25°, in Cerberus. Their courses were generally short ; and the following is Mr. Greg’s description of their appearance :—‘‘ Owing to the moon being so bright the tracks were rendered rather shorter and the trains less visible than they would otherwise have been, besides causing me, no doubt, to miss seeing a number of others. Certainly there was distinctly a shower going on which was not visible on the evenings of the 12th, 13th, and 14th. Five only of the seven were very white ; their average brightness was that of a first- or second-magnitude star, and owing to the shortness of their apparent paths their duration was under P if any thing, halfasecond. The radiants QH, [of meteors on the 12th-13th, in Cerberus] and QH, [of the Lyraids on the 19th-20th of April] appear to me to be simply one and the same shower, with a slight difference in the dates and in the positions of the radiant-points.” The sky was quite over- east at Buntingford on the night of April 20th. At Mr, Crumplen’s station in London the sky was remarkably clear, but * Report for 1868, p. 402. 1872, 1 106 REPORT—1872. only three meteors radiating from near a Lyre, and in the neighbourhood of that constellation, were observed in a watch of three quarters of an hour, at about 11 o’clock on the evening of the 19th. The first of these was as bright as a first-magnitude star, leaving a streak of light upon its course which re- mained visible for nearly a second. On the night of the 20th, soon after 10 o’clock, the sky was entirely overcast. At Bristol, on the 19th, few stars were visible between 10" and 11°, the sky being very cloudy, excepting for a few minutes in the north-east, at about eleven o’clock, when one conspicuous meteor and one small one only were seen by Mr. Denning. The former rather bright meteor is described in the above list. At Birmingham a hazy state of the sky also prevailed on the 19th, and strong full-moon light on this and the following evenings only permitted a single meteor to be seen. The scarcity of meteors on the latter night during an hour’s attentive watch was, however, fully confirmed by the other obser- yations which will shortly be described. “ Meteor shower of April 1872. * April 19th, from 10" p.u, till 11" pu. Sky hazy; moonlight; no meteors, » 20th; from 10" 20™ to 11°20" p.m. Sky clear; moonlight; one meteor. » 20th, 10" 59™ p.a.; brighter than a 1st-mag. star; white; dura- tion 0:5 second. From @ Aurige; path 10°, directed from a Lyre. Left no streak (a part only of the meteor’s course seen, askance).”— W. H. Wood. On account of the overcast state of the sky no observations on these dates were obtained at either Glasgow, Newcastle-upon-Tyne, or Sunderland. A list of six meteors seen at Wisbeach between 10" 45™ and 11° 30™p.m. on the 19th, with a tracing of their apparent courses on a map, was received from Mr. 8. H. Miller, with the following remarks on their appearance :— “There was a remarkable accordance in their direction, and No. 6 seemed to take the same path as No.5. The brightness of the moon interfered with the observations of their colour, and also of the length of their path, especially as they were small, and their trains of light a thin streak. I did not see one on the 20th, although I kept a persistent watch.” In reply to a later in- quiry on the latter point, Mr. Miller adds, “The sky was clear on the night of the 20th, during the hour I watched, and had there been any meteors then, I think I must have seen them; but after 11" 30™ it became cloudy, and there was rain on the next morning early.” _ On the night of the 19th, at Hawkhurst, the sky was very clear, the moon- light bright, and a faint aurora was visible in the north. Between 11 o’clock and 12" 15™, four observers counted 16 meteors, whose apparent courses were more or less exactly recorded. Ten of these meteors were seen in the first, and six in the last half of the watch, and nine were as bright as, or brighter than, 1st-magnitude stars. Two of the brightest meteors mapped were also simultaneously observed at York, and one of them diverging from Lyra was at the same time recorded at Wisbeach. Nine of the sixteen meteor-tracks were directed with no distinct centre of radiation from a space between a Lyre and 6 Herculis, and the remaining meteor-tracks were nearly equally distributed in their directions from the radiant-points WG(?) in Cygnus, S,; in Virgo and Come Berenices, Q,. im Corona, and M, in Ursa Major, Se OBSERVATIONS OF LUMINOUS METEORS. 107 The only meteor from the latter radiant-point (near the zenith) was the very brilliant one seen to fall vertically elsewhere, and described as proceeding from the same radiant-point by Mr. Clark, at York. The Lyraids appeared white and swift, and generally left no streak; but when seen foreshortened near the radiant-point they sometimes appeared bluish or yellowish, and left persistent streaks. The sky was overcast on the night of the 20th, and no meteors were observed. At the Royal Observatory, Greenwich, during an interval of clear sky on the 19th, between half-past ten and half-past eleven o’clock, six meteors were registered by one observer of Mr. Glaisher’s staff, of which three were as bright as first-magnitude stars, and four diverged from the neigh- bourhood of a Lyre. The Lyraids were all bluish white, with short appa- rent paths, leaving streaks. On the night of the 20th, the sky at the Royal ey, Greenwich, was too cloudy for further observations of the April shower. During the night of the 19th of April, it appears, from observations which were continued at the Radcliffe Observatory at Oxford, by Mr. Lucas, until the appearance of daybreak, that the activity of the April meteor-shower was yery brightly maintained until the morning of April 20th. During a strict watch kept for shooting-stars on that morning from 1” a... until 4" a.m, the sky was quite clear during the.first hour, and only crossed occasionally by clouds from the south-west during the last two hours of the watch. Towards 4 o'clock a.a., the brightness of the full-moén light gave way to that of the approaching dawn ; and a thick haze beginning at this time to overspread the sky, at length obscured all but a few stars of the first and second magnitudes. The appearances of twenty-six meteors were recorded ; five in the first, five in the second, and sixteen during the last hour of the watch; the numbers of 1st-magnitude shooting-stars visible in the same times being two, one, and six. Seventeen of all the meteors noted were Lyraids, of which the numbers recorded during the same times were four, three, and ten. Six of the Lyraids were as bright as first, and six as bright as second-magnitude stars, and they appeared white even in the strong moonlight. Their courses were generally very rapid, sometimes 20° or 30° in length, and occasionally leaving a per- sistent streak. Of the nine remaining meteors, all but two proceeded appa- rently from a radiant-point in Cygnus eastward from that in Lyra, not far from the position in May and June of a radiant-point WG in that constel- lation ; four courses prolonged backwards intersect each other close to e Cygni, near which one of these unconformable meteors also moved with a short ap- parent path. The brightest meteor seen during the watch moved from the direction of e Cygni, bursting when it had reached the brightness of Jupiter, on a long course from y Cassiopeiz nearly to Capella ; its duration was two seconds, and it was followed by the next meteor, which appeared as bright as a 2nd-magnitude star, moving upon exactly the same course. Two other unconformable meteors were directed from the radiant-points 8,, in Virgo and Come Berenices. The tracks of the seventeen Lyraids, prolonged backwards, all passed through a region of radiation including the chief stars of Lyra and the stars §, o Herculis, where a circular area, about 15° in diameter, with its centre at R. A. 275°, N. Decl. 32°, would include all the directions of the Lyraids that were observed, and was probably very near the central point of divergence of the group. The radiant-point being near the zenith when the Lyraids were most numerous in the last hour of the watch, and their courses extending round it towards all parts of the sky, this apparent place of the apg a 12 108 REPORT—1872. although not definitely marked by exact intersections of their apparent paths, yet appears to be the best average position of the somewhat diffuse centre of divergence which they appear to have presented that was obtained during the last annual reappearance of the April meteors. The notable absence of meteors on the evening of April 20th, after the somewhat considerable star-shower that was seen at most of the stations on the preceding night, was especially remarked by Mr. Clark, who described the following particulars of the watch which he kept at York for the appearance of any continuation of the meteor-shower which might be visible on the second night :—“ The watch on Saturday the 20th was altogether unsuccessful. IT commenced a few minutes before 10", and was joined at 10" 25" by Mr. rown, when for about ten minutes a cirrus cloud from the cast obscured two thirds of the sky, and we were driven in by a snow-storm from the north at 11" 10™; after which I did not watch, as it remained more or less cloudy. However, during that period of nearly an hour and a quarter, for half the time two watching, we did not see with certainty @ single meteor. Such a remarkable absence of them I have never noticed before. ‘Yo be sure the moon was brilliant, but not so brilliant as to obscure 4th-magnitude stars.” Meteoric Shower of May 1872.—Some preparations which were made by the Committee to watch for the appearance of any star-shower or conspicuous meteors on the nights of the 17th, 18th, and 19th of May, when such have been occasionally observed, were entirely frustrated by a constant succession of wet and cloudy weather. During the hour appointed for observation on the evening of the 20th of May, Mr. Miller watched, with a tolerably clear view of the sky, at Wisbeach, without seeing any meteors. A single bright meteor of the shower was seen at Newcastle-on-Tyne, in an interval of clear sky for about twenty minutes, on the night of May 17th- 18th, at 12" 10™ (midnight) by Professor Herschel. It resembled a Lyre in brightness and colour, and passed in two seconds from between ¢, » Draconis to between Z, » Ursee Majoris, beginning its course 5° before, and ending it 5° beyond those stars, and leaving a bright streak upon its whole track, which remained visible, even in the bright moonlight, for one or two seconds, The meteor’s motion was apparently from the radiant DG, in Draco, and was not conformable to the principal radiant-group in Corona and Hercules (Q, ,) of this meteoric epoch. PArers RELATING To Mrrrortc Asrronomy, A pamphlet of printed instructions to observers of shooting-stars for the year 1872-73 has been circulated among astronomers and the associated ob- servers of shooting-stars in Italy by Professor Schiaparelli and Signor F. Denza, appointing five or six nights in each month for combined observations, together with a list of nights in the whole year for which not more than twenty meteor-tracks were recorded by Zezioli. Observers at fourteen Italian stations are engaged in these observations ; and the Italian Luminous Meteor Association have already recorded the apparent paths of 6151 meteors in 1870, and of 10,257 meteors in 1871, which have been projected upon suitable maps for exhibiting the radiant-points which they present. It is intended to print these maps so as to exhibit the positions and characters of the different radiant-points, with their dates of appearance, as clearly and conveniently as possible to the eye. The star-maps employed by the Asso- ciation of Italian observers are constructed upon the same projection as the well-known Celestial Atlas of Professor Dorna of Turin. The observations AY lee 0 ah etottar wed l). | | ' ‘ - . r’ e 2 SN" alanibes ; iolonsntb ye er odicd fence sorve-dincball 1G err Va rivadd’ a’ ifiioX mow =» 1) i) ale B . ‘ , : x « ; ae eee ae er, Be ie Ag < oe) PRE be botdeola 3 teil ' ae mod Pek oo eet Ja feeio 7) i c8s: loteoto = eo4 "41 Jeni de WleytH orto; h feurmizhlt “Stites avert Shtelud 2° “errottewwelo naoiticor 9d Deleon ® - ral as-is Z ash ov C258; " Taoyt - il sem) =~. .°2¢-4-" 08s _s6 oadens abriitiial Vaal ne fears uri {idado 1 Ale rep Blea) ane <0 LE Sa ae ie ‘. i Sehyrt ity : anaitedind doris rorncatibh Sor oa mode db PRE a Bite ( i, ¢ at ~ ~ 7 : or: ee ere - I finales gg Reon '20% vA eto a net cert) be Berd oe be dsie'3 fs dint) ena Pas * a ope ont 0) eley hehe t . . Sharer 4 bea SE "Oil Ay vie. | } all: mug GE ad puiko 705 Dye otarginols ri nilest wieer er gh sop ptt The ele et tye > a peru car4 bled t yell dé ipeiiv til in a _ldailurg dilostewk mi ae" qeerc ‘Vo ad meee (eloH Yo 6) atrinthes te Hew er dosh ori} fidtn * Soon A Hh of ety A aL amen sorte 7 iy Ri ery iy . i+ 5° ope in (eae) 8882 Fi tomoI= 282 w Jroteinrnnitins piel : : a _ Bri ideusts ia aes) “ew Birt et ” iz 2m to dhehrMindsepiosd AMindor'd | vas a Cen me ea a pases MeN Ao) edhe eat ont Ui oethegds faut AS GCE oe ers) ‘ Hest Bevo 7 OM itw iil iaicesad oe apish Bea shale Fae dire)” on Oe tod Veo drt) toll 2 Pe L an Wier = aid i'l 1+ OAT Yo gettin May £ DC Yo tavamencru tithes relied “pete te. ; m . (02 .0% oni) Sf1g pipes 0 il Sdpen priscuinan aa meses Rt +" £ey Sei ? weet tins | LED tote 0 aOR! ,. wheeene "mS Hai Jord ‘fants silF tial laoidesbi yldeclprt AivgA.g Funded rr A. $2881,4 = Steg "6s3) Bost, A Jeena wr ole oldaion : 2 OF T POSITIONS AND DURATIONS OF METEOR-SHOWERS aed p> 108. A GENERAL COMPARATIVE TABLE OF THE RADIANT-POSIT of shi Vished int Greg and It pat 19 met & r ai . 1848-70 (Dit Ase Germany publ . 16 Kngland Li Tealy eke Tn cor Avornge position radfscls exit , radiants * 2," by 3 I A } i a F uration of N.B. Radiant-aren supposed to be 15" in diamet in ti aah y ia f Name of radiant} thowors sate Mrs Grog; from Z pe ; ra A ioeers ' ye ee n I Doguilawaki"t Ra. |W. Ded R n 2 : a Dec.ixgita Fob::14 : 3 wna Teadia \ + etn 3 a Ledge * | ; Ione January 1=1 Fr 1 [ac Doctre atabontrgge+qst, Comet of 16807 (Vi ‘ 2 . ° nn 1 to Feb 9 ' 4 $ 5 : s |e Tadiant T f 1 Cc borated by American observations A notable meteor M the fi i ‘ 8 as [Kus Deo. 1510 Jan. 8 ' Kus x - b : : : : ¢. \lng Maala's Annes t Git | sprue Protabil 5‘ j - ya ‘ Ph ten January 6 a8 aioe Jan. 16 to Feb. x i as | M Hedin ; reat 18" 5 . . ¢ t I ai fr oe . : + [Gen : Melton ( ; ii . I F tif . Mart 14 usr ° Sais ; i ; : ° 2 ‘ ; NT by Afr, ¢ Denia’ observa ¢ ‘ > ° . rh 6 + |K s a i Had ple. ¢ 2 y ¥ 4 4 A t { z 3 : . a H Fr 5 Nitec : ° : ; +. |c : i ' tf F ar, 7 5 Mareh 1 1 ; M K K 3 eK M ' a ; tho € : ; Fob 15 to Mar gt | 1 i : ' é ' ' rin Australia ron . A RA RA : I : F x ‘ ia : o mulle Meteors «mall p t . r ‘ = bd : Feb t ‘ ‘ = a : 1 . . . ai F iy zZ t rt v + 4 e . . rn i ‘ M 6 f ¥ : , : Satara we E ‘ M y : é M 6 April 1 4 My? i f un « s : : W 5 : > |G j Comat IV. 1 5. K ‘ : it : oe Api. Probably id 7 R qua Ip reaiia Prof : . 3 : +) sw lou y ; ay Apel 15 : 5 > [ar x apes Piper ; ; pull Mor j ; s : = p x apres | 398 ry April's 1 184. 2 + x M7,37 i = || cersh rof. 8 rn O54 2 , z . i ation of M6 er 4 nM . x April 1 . i i No R r . . : z ; i : = ¥ = © | Caret Ww ; : i ree a May 1 7 na N i I rook, i : = “ J May 1-31 ’ . = = . : iit sf Te \ RA 4 : ghee 2 é May sent 1 ° 4 . ° . | June 1 |B 5 = . , : a J } Ww Tein, ee Ep ae 1 4 : : ay” ng A \ ‘ r j tapiay se i P E. Clark, at ‘ xo a < | Caret Mote ze0t+55%. Centre a16°4 57"? C A by 2 I . J Aug 16 & [as Aug, 1-1 5 t 1 » . sti 5 3 o rol A. 8. It 1 1 Perhaps=Q ‘ Spe 5 | 90 [Nast July 110 Aug. 31 ; : insne i Ff Se ot EN3* in byte 2m Comet IIT A : 5 vata dug x s joa |x A . » |cure Yi (lor Au cursayer nol Tela hemisphere radian } Naa Jali i gir Augaws 187%, se ASW} See No.1 = bin a1, 485 130) put a Nees lds 4 A : : Pei: i with Rs, 3 of Gand IZ Spi. 6 18 4 (¥ ‘ : 5 A welledefined m ‘ Fis6o-71. Max Aug. Comet IE, 19377 (Weiss and Schiapa ie is tr peers i x [Bo : = 2 ‘ r ; ; 3 ; Z H 2" | Cart ay sveclll ixghit Hetr's position t ial by Gand I. See No. 6 B large test July. 18-41 i |e a 5 + | cart well defined 1 |ts7.a39 143 ee fT D Aug. t “ Ojai Sara ery " p [Ata ir NU, the Peres ha sled radiant-ares extending froma Perseua ta ( ‘ : Shee alopals. = Oomet TIL, 1 : i ‘ 3 uw |Tue . . a hone of 5 ea | Pa “ deats4 ta Geplae a ? > | Com ph 19 9 Ort 30 1 is Bap 110 Ort 1 1 ' y a6, 151 Aug. 10 40 Bet i A ‘ + 2 A woll-rancked Sep 55: “Requires {ether investignt 7 i aA AeA ee sel Pace ese Lee ; males Deroisick alata igh aA an men Nowe * “ 1 iba, 166 4 7 Multi ridiant; ceotre ab An iinportant Hofined F Rorinbed| Sieras] seapilaeny October 16-31 »| 4 h a! s S 3 meleorio shower, with tondency to advanco with the tine from 7574-45" to os +54" ; r) e, |e . 7 oh || tere October 1-15 97 6 |Ans ul 4 6 | ise ; * oures : i ol canst te " at |i a in 4 Cart 7 " | Tmiorked shower; radiant precise nt'» Orionin cs 5 o | Caret ‘ 5 ‘ October 16-31 305 4s oh : + | care ° 4 Odober 16-31 | se | 6 ents 110 : scare pmabnutesy el 8 October 16-3 y | pervallcni raqured for thls shower i 30 | 365 Oot 35 to Now. a1 6 4 Noveriber 121 | 16 Mr, Dackhouse, 4-6 Nov. 1869; radiantesq?-416"; and also observed at + u 5 ss | Greenwioh, 13 Nov. 1870, at ¢5°-+25". Generally a woll-uiarkel ahower at | a Tauri L e . © | Cares Oot. 41 to Dee ta 14 « jut s fs Py comb 9 bs | ae lay iu 3 pps A | > x ° |Ge reenter 18-13 1” 37 | 468, 170. ‘ ‘ © | Caret . . 1 with 1 é H 2 | Cora November 15-1 149 ; Nor. 13-15 % "identical with Comet I, 1966 Soveaber 33-14 is (Dens) Sein) Ay ame |r ara 4 > Obscrved by Prof, Denua, 1870, (?==pwoudo-radiant of A 16, Ps, 5 of Bt 3?) ° ; 5 Gara Nov. 35 10 Dee. 9 a s 279 56 x ‘ HH November 1y+t4 | 40 | oo lapr [Nov 33 toDeo.1 s| as. | OorsiaNor.yo | 4s | 46 Connected wih W378 and 2 No. 171 probably apwuloradiant, Roun | further Inveeligatic iia Novenber 13-17 “7 $8 | 169, 178 ° js «| Caro . oe I \ 1 is vember } 7 | os lib Bole Moat crs ti tualy o \\ekea lallant probably sloogated. Supposal by Wain, D‘Arrest, Gullo, and Sehlaparsll v 5 reas | sete [Ana 15 5 7 | to be cunuieolod with Diela's comet, A 19 of Haiseai®-igye i i Kor 10 to Deng ras | 56 bag 175, i Wie | 146 . 2 Ic ee nite ‘ ‘ ; 1] Observed at Greenwich, 1879; radiant near Cor Caroli; indistinet . ny Deveunter 35. ty | a7 410 Dea 19 ie | . ‘ 5 {ccf Madiant elongoted.140°-+70" to 199"-b7a%, Shower well sharkod. ig ° ‘ © | Cares i ° . 7 Nor, 19 to Deo, 15 iy 4 |Nig.20 iy November 59-46 yes | ae | a74 075 Nov. a6 Dew 30 | 100 December t=1§ maf capt Beg 4n {oporlant meteorlo shower, Maximum 11=18 Dex Tuadiant-contrs 8 Gomi n | oru Tadiant at 105" +4: Th P. Greg and 1, Wood at 1oo*4-34° in 186 longated, go" 49" lo 105*-b al December 9 a6 ms . . . : 2 December 9-41 | 63 [ayy 18, - | o | Deormber Ya 8 . s 139 (7h | December 34 4 cee et Pouibly commencement of No. 7 (Jan. 6). | . esa tent eal Late Avsovtliorn radiant in tho list of Hols and Neumayer, From obsereatious i Kogland, 9-1 August, 1871 ro | | . x . . . } Mectuce ty 10.1% Grog fromm tho Radlite observations nl Oxford, 180-91 Hague translation of Hlgparal' work, Wotwurt be. p, 24, Astronomische Xwohriehten, No. 164s. lia Assoviation Keports, vol. for 1868, ‘The lost three Now in this list are supplementary radiantpolnts reeeally confirmed or established by Mr, Greg. + i OBSERVATIONS OF LUMINOUS METEORS. 109 of shooting-stars made at the observatory of Moncalicri continue to be pub- lished in the Meteorological Bulletin of that observatory, in which nearly 1000 meteor-paths observed before the end of April 1869 have been already published, All the observers’ notes are also transmitted to Milan for final reduction and arrangement in a collective Catalogue by Professor Schiaparelli. In connexion with this extensive research, an enlarged edition of his ori- ginal Memoir on the Astronomical Theory of Shooting-stars* has recently been compiled by Professor Schiaparelli, and was published last year under his directions, as a separate volume, in the German language by Dr. von Boguslawski, of Stettint. The materials of the original Treatise have been much increased, so as to present a full account of the recent investigations in meteoric science whose results have most contributed to advance this modern branch of astronomy since the publication of his former work. A complete Table of all the 189 radiant-points obtained from Zezioli’s observationst, the full particulars of which have not been previously published, is also em- bodied in the work, with a supplementary Table showing the position of each radiant-point with regard to the apex of the earth’s way, and the principal elements of its parabolic or cometary orbit. In a list of notes on the several radiant-points, a comparison of their positions with those obtained by other observers, showing them in many cases to corroborate or to correct former observations, is made to connect the new list of radiant-points in every im- portant point of agreement with the older lists of Heis, Greg, and Schmidt, _ and with the separate determinations of special radiant-points by individual observers. A useful summary of these results is given by Mr. Greg in the accompanying comparative Table of radiant-points, presenting in one view all the points of difference and resemblance between the several general cata- logues of radiant-points which have hitherto been published, with the excep- tion of the extensive Catalogue recently printed by Dr. Schmidt in the second volume of the publications of the Observatory of Athens, to which the Com- mittee have not yet been able to refer§. With the aid of observations received since the appearance of the last printed Meteor-Catalogue in these Reports, the Committee propose to consider more closely the epochs and positions of the general radiant-points exhibited in this Table, and to enter in a future Report into a complete discussion of the identity and of the comparative im- portance of the different families or groups of meteoric showers which, in many instances, it appears most properly to represent. * «Note e Reflessioni intorno alla Teoria Astronomica delle Stelle Cadenti.” (See these Reports for 1868, p. 407.) + Entwurf einer astronomischen Theorie der Sternschnuppen, von. J. V. Schiaparelli. Aus dem Italienischen iibersetzt und herausgegeben von Georg von Boguslawski (8vo, with four Plates, 268 pp.). Stettin, 1871, Verlag von Th. von der Nahmer. ¢ A Table of the principal meteor-showers only of this later list was formerly pub- lished by Professor Schiaparelli (vide Report for 1870, p. 98), with slight subsequent alte- rations in two Memoirs in the Ephemerides of the Milan Observatory, containing annota- tions on the history and characteristics of each meteor-shower of the List, one memoir in- cluding the meteor-showers observed in each half year. That for the first half year was noticed in the last Report (1871, pp. 44-48), and the concluding Memoir has since been received by the Committee from Prof. Schiaparelli. To this complete cycle of meteor- ‘ showers, and to the descriptive notes which it contains, further consideration will be devoted in the next Report. § The same Table is also presented by Dr. Schmidt in the ‘ Astronomische Nachrichten,’ ~ No. 1756. 110 Date. 1783. Jan. 8 Sept.26)... Nov. 2, 1794. June 28 1871. Sept. 1 Oct. 8 11 1] Noy. 9 ll 12 Hour. hm s Eyening ...|Slough, Bucks,..|Very bright eee reeeeee 8 55 3 55 p-m. = p.n 11 56 10 p.m. 8 17 30 p.m. 7 45 p.m. (Possible error 2™,) . Knocklong, p.m. Place of Observation. eeeeeee sere ree nereee Knocklong, Co, Limerick, Co. Limerick. Between Alder- shot and Farn- ham. Regent’s Park, London. ‘Brompton, Lon- don, | Royal Observa- tory, Greenwich eee eee eee e rene Tenby, South Wales, REPORT---1872. Apparent Size. Brilliant ..... eaeces? carseeeemerceoete Large and bright... Fully as bright as Venus. Nearly as bright as Venus. Very large wee eeeaee |Brighter than Ju- piter. Brighter than Ju-| piter, Brighter than the fixed stars, GENERAL LIST OF BOLIDES AND ) Colour. Very white Rocket-like ........./.. yen ee sees asco rye Very brilliant ...... Seay sagegeseis oeab| > Very bright......... Showed most beautiful co- lours. WWM b ant vesuss Intensely vivid green. Bluish; the fragments crimson, Bluish ,. Bluish-white . Orange-yellow Duration. Te eee e tenner nee see been enter eereee Slowand state- ly motion. Slow motion. . Two or three seconds, 6 seconds. 6 seconds. ... 1 second 2 or 3seconds. Slow motion. ..-/Dropped from 6 Meteor-streak. Ursa Major. .... Moved from Pola: eee eeey Position. COO nent meee ner eeeenns ...|Passed along close | under @ Lyre. Cygni. Ee In the southern sky’ at an elevation of} about 20°. First visible nea Pegasusand passed across the sky to} Capella. “2= From 328°+17° | to 300— 23, ending its flight} a little beyond Aquile. From altitude 45°,| 15° W. from S.,} to altitude 30° or| 35°, 20° W. from} Ss, By the side and to the north of Ju- toris from Pollux. in a nearly straig line between e¢ an ¢ Ursee Majoris. Passed between and e Leonis. | halfway between and A Tauri. Course.as in sketch A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS, RIGHT METEORS OBSERVED IN 1871 snp 1872. Length of Path. ——- —_—— —— Beene rere retetnne IEE. scccaseenns Long course... Peepereopees vecens Deeeeearerensees Fee eer eeeree Peete e ee eneeewraalene Ahern cere ee etrenie Direction. Fell perpendicularly to the ho- rizon. ee eeeee PO ee ee verses seeeeeene ..|Directed from js Urse Majoris OO e eee eee ae en eeeeteseeeeeeans eenenes Horizontal from east to west. ‘Directed from Andromeda...... Path curved. 4 Dropped straight down .....+++. Pree eee ee .. (Left a slight streak..........sssesves Appearance; Remarks, &c. | Globular nucleus. Left a streak! visible 40° after the meteor had disappeared. Gave a very bright light. Left a luminous streak visible for 1™ 20° or 30° to the eye, and for about 3™in the telescope finder. eee rece r errr rere cere e reer) eee enneeeee Resembled a faint sky-rocket. A portion of the train in the posi- tion shown in the sketch re- mained visible for 3™ at least. | Pewee eee eeerereereare eee eee eee eesesaee Several other meteors were seen on the same night, but none so conspicuously brilliant as this one. Disappeared gradually; left along, broad, blue streak for 4 or 5 se- conds. 1°27 i 2106 | 1°35 1°76| 1:62) 2°63| 3°60 SI ¥18 |) 2°48) 4°06), resiieery7 : TST Pts 1°54 84.) 3°28] 214|] I-77} 1°31) 46g) 51) 149) TOL "75 ; 156} 2212)" Te09)|' =2¢92)|— 1:05 |) 2475 “95 k= 3°39 *66| 3°70 83) 2°12 I44| 1°30|) 1°08 "95 76|) CLeTS:|\s 220g.) e125 1°31 "74 “OZ Cran "90| 1°95 63) 2°73 21) 3°72|| *54| 2°31] 754] 3°20|] °74| 3°34] 307| 633] . 99] 2°88 130} 4°34]} 1:02] 3°14|| 3:04] 3°46 *§2| 4°67 24." 3740 jlo Ts | 3°50|,.. 2558) aes 1°13} 1°42 40} 1°77|| 2°92] 149] 1°70] 1°94]! 3°00] 1°64] 1°74] 1°66). 2°40 68 1°62] 5°52 86) 6:43 "70| 5:27] 1°93) 5:09|| 1°82] 6°87) 19} 7°53 *84| 6°08 2°88| 2°25]! 3°96} 340]| 447| 2°98| 7°26] 5:cg|| 3°38] Fog) 3°99} 3164) 4°43) 189 2°75 56 || 1°78 95 || 2°75 *$g| goo] r1rl| 2°54 86] goo] 124) 1°78 42 2°02] 240]] 1°67] 1°53|| 2:41| 1°32] 2°71] 4 gol] 2°53| 1°86) 1°88) 1°92]. 1:96) 124 — SS ee —— |__| —} ——_—_— — 19°15| 27°96|| 16°77] 29°17]|| 21°48] 26°06] 31°26| 36°00 | 21 76| 27°63| 21°40] 33°71] 20°61 | 25°61 Division VII.—Norrn Miptanp Counties (continued). Lincouy, Norrincuam. Lincoln. (Market Rasen.|Gainsborough.| Brigg. Grimsby. |New Holland.|| Welbeck. 3 ft. 6 in. 3 ft. 6 in. 3 ft. 6 in. 15 ft. 0 in. 3 ft. 6 in 4 ft. 0 in. 100 ft. 76 ft. 16 ft. 42 ft. 18 ft 80 ft. 1870. | 1871.| 1870.| 1871.| 1870.) 1871.) 1870.| 1871.| 1870.) 1871. |) 1870.| 1871. in. in. in. in. in. in. in. in. in. in. in. in. #35) (**70] © 10] ©" 97] *E-r0} © 66) i yo) P3239) rts | 78). cae r72| 1'95| 302] roq| 2°41] r79] 1:23] 1°44] 1°63} 1°89]/ 1°62) I4t moog |) BR] e Gr y's Brg Pea bh G5) f a5) 8 77) OOo | Ot Bi). aes “68 | 3°06 55) 477 “44| 2°91 73) 2°74 43° 3°07 "66! 3°05 63) 1°25 76 “44 SSO Tt 75 OH 58 OA) Sis “5}| aes 1°88) 3°40; 1°38] 3°35 | 248] 2°57] > 180] 2°21}? 3°33 3°61 |)...1°89] 3°71 *g0} 37°00} 1°05] 2°94 68} 2°73 *30| 3°26 76) © 3°O5 |)... .*60.] “gtax 1°87| 10g} 1°56] ys'o4] 4°74) 1°76)" 3:68) 1°37 1°64.| 1°07 ]}.. 1°13 98 r21| 4'06| 1:22] 4°68} 1°46) 5°87] 1103) 4:06) 1°13] 5°O7]| 1°21] 5°31 9°58) 43] 515] 116) 6°73] 103] 5°37) 31°35] G15] B02) 5°58) 3°78 I‘gl| 1°77 53] og! 3°42) *a-16) 2°25) 1°39) | 2°12] © 3°85 1°81 82 199] 1°62] 1°31) 118] 2°84] 1:29} 2°90) 1°41) 3°43] 1°31)| 2°48) 1°57 25°26| 23°15 | 16:44| 22°37] 24°06] 24°17| 20°10| 22°68 | .23°67 24°56 | P2 21°58| 25°48 196 REPORT—1872. ENGLAND. Div. VIII.—Norri- Division VII.—Norru Mrpianp Counties (continued). “UT ractaaei MU NteIE BSTE NTIES. | Dersy. Cuesnire. ; castarels, Cholmondelly. Height of Derby. Chesterfield. |Comb’s Moss. Peith "1 Macclesfield. Castle, | Rain-gauge NA: Nantwich. |} above Ee Ground ...... 6ft.0in, | 3ft.6in. | 3ft.6in. | 3ft.6in. | 3 ft. Gin. 1ft.6in. | Sea-level...... 180 ft. 248 ft. 1669 ft. 965 ft. 539 ft. 42 ft. 1870. 1871. | 1870.) 1871.} 1870.| 1871. | 1870.| 1871.] 1870.| 1871.) 1870.| 1871. in. in. in. in. in. in. in. in. in. in, in. in. || January ...... 1°43 F32) (is t°9 Qi) est! p e3i92 ||» e1°59 12-3794 | a ees Sule arog: 977) 5°73| SESS February ...) tog} 151} 1°84] 1°94) 3°08] 3°23] 2°42) 3°84 8g] 1195 | 122] “27541 March ..+.....| 3°47) 15} 2°25], 1°18) 3°95] 1°75 | 3°24] 146} 1:85 976)|, 42°52)| eS APril baesesecs EN tm ke “25 |22°25 | 1385.) 6'29)|. \1°57 | .4rgoi| o.1°78 esa ego Reoes MSiy: sarees 507 PFPA OS mek 2218 | EA Ou ety || | ecole (2I0g Regia “73 | -2786)|| Sarg eae PNW Meese ce 1°23] 4°16 798} 4°23] 81] goo} 169} 4°85] 1°93] 3°97] 1°70] 3°18!) uly: .eescbasct "79| 4°68 "83 3°39] 2°83) 4°86) 4178]. 4°53] 2:02| 5:78] .m50| Shag August ...... VBE gai 2 Hs 66) Ig] 81] 2°94] 1°57] 2°45] 2°06] 1°93] 3°54] 129 September...| 1°13] 4°92] 104] 4°80] 3°26) 667] 311] 475] 2°62] 4°53] 2°21) 4:90) October ...... 491] 2°37] 5°58] 2°9r} 9°92] 4°93] 11] G03] 5°67] 5:92] 5°44] § 3°97) November ...} 1°99] 1°05] 1°95 SSIs |'§ §2,70)|atz98 pee 82) e179 84] 2°47) 2°46) - 1°34 |) December ...) 2°07} 1°29] 2°41) 1°30] 3°08] 3°53] 2°62/ 2°33] 31°80] 2°51| 2°86) 1°69) Totals ...... 18°73 | 28°70] 21°00} 26°56] 40°24 46°12] 37°90 41°55] 23°83 | 36°34] 26°21] 31°73 Division VIII,—Norru- WerstERN oF fax A 5 " Division [X.—Yorxsurre. Counties (continued), LAncasuire (continued). Yorx.—West Rivine. Broomhall . Height of ne on Park, im ld. Tickhill. Penistone. Rain-gauge Bncaber. ecient Sheffield. eae above ee pe ee EE EEE Ground ...... 1ft.6in. | 4ft.8in. | 2f-Oin. | 4ft.0in. | 2ft.0in, | 3 ft. Gin, Sea-level...... 120 ft. 155 ft. 340 ft. 1100 ft. 61 ft. 717 ft. 1870.| 1871.| 1870.| 1871.] 1870.| 1871.| 1870.| 1871.| 1870. | 1871. | 1870. | 1871. in. in. in. in. in. in. in. in. in. in. in. in. January ...... 3°96| 195] 4°34] 2713] 2°82] war} 3°63) 4325) 121 96) 3°52] 74h February ...) 2°64] 445] 2°76|) 437] 1°85) 210] 2°87) 311) 137) 1°54) 2°15 2°76 March ......) 2°56] 1:89] 2°28] 2°23] 279] 1°26] 2°71] 1°38) 2°13 °33:|) Saran|| sinega, PATTIE setve oe. < 1°76| 2°97| 1°60} 3°79 66] 3:12] TIQ| 4°74 “49 | soci 88} 3°07 Nay iSiashencs 2°51} 1°78] 2°79] 1°81 BOd|| at42 | 92220)|! E77 “58 | 2785) 62 | oa-gir pie \.oretese 2°12] 2°44| 1°88{ 2:25] 1°27] 4°63] 369] 3°82] 2°08] 4°23] 3°93] 4°42 July...) 2°02] §°97| 1°56] 4:93] 97] 3°08] 118] 3°42] "78]| 3°63) °55) 2°63 August i... 2°27] I'95| 1'97| 3719 *86| 1°65] 147] 2°06 5O74) wih 59 *98| 1°83 September... 3°39/ 3°96] 365] 3°78] 1°63] 640] 238] G09) “68| 5:23] 266) 6°34 October ...... 9°86] 6:14] 11°30] 6°36] 7°87] 2°74] 9°67] 3°30] 5°71] 351) 866) 3°13 November ...| 3°02] 1°81] 3°07] 2°36] 1°92] 1°52] 2°22] 1°86| 1°73 "89 | 2526) px5y December ...| 3°56) 4°28} 2°64] 521] 3°03] 450) 3°16] 2°03] 2°97] 31741) 214] 139 Totals ...... 39°67] 39°59 | 39°24] 42°41] 26°01 | 30°63) 33°46] 34°32 | 20°68) 26-44] 29°56] 31°55] | ENGLAND ON THE RAINFALL OF THE BRITISII ISLES, Division VILI.—Norru- Western Countims (continued). 197 LANCASHIRE. : Howick lton-le- Manchester. | Waterhouses. rae od Pi Behn Slack h or Stonyhurst. reston. 2 ft. 7 in. 3 ft. Gin. 3 ft. 6 in. 0 ft. 8 in. O ft. 6 in. 1 ft. 8 in. 0 tt. 8 in. 106 ft. 345 ft. 283 ft. 38 ft. 73 ft. 29 ft. 376 ft. 1870.| 1871.| 1870.| 1871.| 1870.| 1871.| 1870.| 1871.| 1870.| 1871.| 1870.| 1871:| 1870.| 1871. ‘ - —- — — ——— — | in. in. in. in. in. in. in. in. in. in. in. in. in. in. 3°13 3°25 || 122) 3°95) (B70) aay} 132) 3°30) 1°50) 3°30) Fi20) Aer 73 Res) |e 2°73 “95 || 9°31 |) is4a | .At59 |-ae-o2 || 12782.) > 1:20] 3°20] “xe72 | ~2°3S!| | arOR) | meAgE meee reso) 2°02 1°26|| 3°31] 29] 2fog| ai2| 2°30] 2t00] 2740] | 1745) 2:92)|/ mpg 2°22) 3°52] 180] 4°39] 2°46] 3°78] 1°44] 2°56] 1°60| 2:40] x10] 2°20] 2°64] 3°60 *75| 2°07] 13) 213} gr] 41°86) 162] 162} I-50] 70} 345] 1°45] 1°95} 1°80 I79| 2°66) 147] 4°72] 4:01) 3°57] 3158] 2°05] 60} 2:25] x35] 175] 2°23] 3°36 Bar) 3°55 | 22700) 4°32 |) 123] 4°32 55) 4°94 65] 4°80] r10] 443] 2°27] 8:08 Mose e0o|) 9 2°24.) 2°7r || 251 | 1°71) -2r2 | ixt0g| 3°rO| 2°00! 1°23] 41°38 2°87) 2507 2°66| 3°82] 2°26] 4°93] 3°78] 5°30] 2°72] 3°62] 2:90] 2°90) 3:00] 2°90] 3°99] 4:20 8°36) 4°51} 11°33| 4°75] 11°54| 6:11] 8:80] 6:90] 10°62] 6:90} 9:60] 6:15] 13°36] 6°58 Bao erar|) 3°05| 1°57| 3°89) 2£°76| 3°14] Igo| 3:00] 1:40] 2:70] 150) 3°52] 2°08 Beez 250| 2°14.) 2°60) 3°57] 3°64) 2°37) 2°51] 2740] 37:20] 2°66) 2°65] 4°09] 3739 29°55| 33°23] 33°64) 36°91 | 43°47) 40°93| 29°84] 31°95] 34°7| 34°25] 31°41 | 29°94) 45°56) 43°91 Saddleworth. 1871. in. in. 9728 || 12°07 186) 2°35 259) 2°14 a7 | * 3°59 165) 2712 239) 4°03 113) 4°67 221 | =1'97 ass) 5°24 997| 5°07 2°88 86 3°05| 3°62 38°11 | 37°73 Division [X.—YorxsuirE (continued). Yorx.—Wesr Ripine (continued). Longwood, Huddersfield. 4 ft. 6 in. 650 ft. 1870.| 1871. in. in. 3°33 “gz 1°56) 2°34 2°54) 96 *96| 2°89 rr7 || -1°39 118} 2°96 “47| 1°56 99 9° 1°94) 2°73 5°47 143 2°78 ex 175 *65 24°14] 19°04 Ackworth, | Well Head, Or pden Eccup, Pontefract. Halifax. Hl oon; Leeds alifax. Oft. 3in. 0 ft. 11 in. 0 ft. 10 in. 0 ft. 9in 135 ft. 487 ft. 1375 ft. 340 ft. 1870. | 1871.} 1870.) 1871.| 1870.| 1871.) 1870.| 1871 in. in. in. in. in. in. in. in. 142 *66| 3°36| roo] 3°80] I'50| 2°26 7 147| 164] 3°77| 2°60| 210] 3°70] Y07| 2°34 1°89 “Gib e2:20i | © E08 |) (2:40)||| (r-ToO |) sey) e09 “42 | 2°75 Bo} 3°38] 1°70] 5°20 eM Sb "75| 1°50] 1°43] 17°90] 2°00] 2°20] 1°36 "97 1°73| 513] 478] 3°28) 180] 3°50) 1°54) 3°70 68) 2°71 "Hail OZ 77), eke OO 15430 80] 3°58 1°33| 81) go] 28) 450) 70} 1°93} IIQg *93| 5°80} 1°76] 4°73] 2°00] 4:80] 1:05] 6°70 5°53| 1°69| 8:96] 2°98] 10°80] 3:90) 7°26] 3°25 mens *96) 2°74 *87| 3°20] I'00} 2°19] 1°04 2°93} .°99| 2°94] 1°43) 3°cO| 2°80) 3°39) 144 20°83] 26'20| 29°59] 27°90| 35°30] 36°70 | 26°29 | 29°82 York. 0 ft. Gin. 50 ft. 1870. | 1871. in. in. 1°68 “70 1°88) 251 80] 21 *66| 2°76 1'08| 1°31 280 |. “aezy *51| 2°80 1°58] 1703 1°18] 6°60 610] 2°67 193) 125 3°16) 2°12 24°37 | 23°68 Se, 198 REPORT—1872. ENGLAND, Division IX.—YorxsuiRe (continued). Yors.—West Rivne (continued). Height of | Harrogate. Rain-gauge above Ground ...... O ft. 6 in. Sea-level...... 380 ft. 1870.| 1871 in. in. January ...... 2°59 "79 February ...| 2°72] 2°98 March: | saa. 276)! | aisig April .e : 200 REPORT—1872, WALES, Division XI.—Monmovrn, WALES, AND THE IsLANDs, l | Monmovrn. Guamorcan. | Carmarruen. | Pewnroxe. | BRECKNOCK. | f | Carmarthen || Haverford- | Al Heicht of | Llanfrechfa, Abert ; ae tens armarthen averford- Brockncou | Pe ence Newport. Een ii Gaol, west, reer | above ee ee, Ground ...... 4ft.Oin. | 1ft.Oin. |] 14f.9in. || Oft. 6 in. 1 ft. O in, 2 ft. 0 in. | Sea-level...... 360 ft. 220 ft. 40 ft. 92 ft. 95 ft. 437 ft. | 1870. | 1871.| 1870. | 1871. |} 1870.| 1871. |) 1870.| 1871. |] 1870.| 1871. || 1870.) 1871. in. in. in. in. in. in. in. in. in. in. in. in. January ...| 4°07| 2°39] 2°96] 3:05]! 2:44/ 3°65|| 4:17] 4°80]] 4°28] 6:05]] 5:22] 7-14 February ...| 4°27| 3°37] 4°24] 2°63|| 249| 2:40/| 5°55] 4°02] 3°92] 3°31 || 8°38] 3:42 March ...... 190] 2°53] 1°96] 196/| 2:28} 1°73]/ 3°99] 3°06)| 3°88) 224 33 | ig"75) ADE. Seccaes 233) S16u15 "2 | 374 23] 4°10 81} 4°69 "71| 4°44 *50 4°76 | NRW. tiesto: 2,,62,|| 1200 || 72:08 $87; || 92377 86 || 3°24 89 || 3°26 53 || 3°03 “gt JUNO chiens. -22)|| | sO irr lemesag)| |) | mages 78 80] 2°99// 18] 1°50 #22) nao | OLY seceea re 3°31| 5°20) 192] 4754|| 31°83] 5°34|| 1°74) 717/| 2°21) 4°97]) 1°73] 3°30} August ...... 3°85] 4°60] 1°39] 2°46]| 1°87] 1°70]| 2°68] 3°28]| 2°70) 2:18]] 2°75) 48x } September... 2°79} 8°32] 1°50] 6°62|] 1°91] 2°99|| 2°80] 6°66]| 2°75] 7:48]| 2:89) 5:25 (October>.<.:.. 8-25] 3°76} 6°22] 4°93|| 626] 520]] 9°36] 7°38] 8°52] 7°64] 10°20 5°99 | November...) 4°64} 321} 4°68 85 || 3°52] 1:28] 5°64] 2°09/| 3:98] r'8r]] 618] 1:05 December ...| 2°54] 4°67] 2°43] 2°72|| 1r'or| 2°66 1°85] s5*0o9]| 2°62] 4°58|| 2°14) atog Totals ...... 38°79] 45°11] 29°90] 36°80 || 25°94] 32°69 42°63| 52°12 || 4o'or| 46°73 || 43°57| 46°71q) Division XI.—Monmovrn, Waxes, anp THE Istanps (continued). oe it et | Carnarvon (continued). Istur or Man. GueERNsEY. Height of |Plas Brereton. Llanfairfe- Llandudno. Douglas Point of Ayr. || Guernsey. | Rain-gauge chan, Head. ay y above | ate é Ground ...... 1 ft. O in. O ft. 8 in. 0 ft. 6 in. 0 ft. 6in, 3 ft. din, 12 ft. Oin. | Sea-level...... 25 ft. 150 ft. Comte! 9) aes 27 ft. ? 204 ft. 1870. | 1871.) 1870.| 1871.) 1870. | 1871. 1870.| 1871. 1870. | 1871. || 1870.} 1871. in. in. in. in. in. in. in. in. in. in. in. in. January «| 3°74] 3°74| 3°85] 3:96) 280) 187|| 3°43] 3°37] 2°30] 2°05] 3°45] 5°91! February ...{ 1°93] 3°03] 2°38] 3°05] 13°53] 2°02]| 2°89] 3:28] 2°55] 2:94]! 1°88] 2°05) Werch Sere. 260 || 2:24.) Pears || Sree) S188 "77 | 2°18| 125) “1°60 | “x°rs || 255 |e APIA ts. esc: 2°03)|.('2°19 | “2220 | Segt5o) |") 92108)| 72-57 533 | ma 25 49} 2°58 "76|> 3°4g INEAY sete cates 1°49 T75)| pba 33 £73) eto) ros ras | parka) “6r]} 1°65 7a UNE sesccoees| | 30)| sae aro | wey | o6| 2:07 *63| I'12 *g0/ 118 "21 ] 2°51 July sesso] °83) 4°65] 89] 329] 54) 3°33 |} 55] m70| °75| 3°73|| 3°26] 3°97 August ...... T7995) 184) r6r} 9137] 7:44) r24)| “1:65 ) 3°72) %r:28) T27 VOI] 1°43 September...) 2°57] 3°14] 2°55) 4:41] 2°18] 3759|| 1:42] 4x21] 2°31 88 66) 5°31 October ...... 5'27| 5:71) 9°34) 6:19) 97:04.) “6°x7)|| 5°65} “6:51 | 85-82] gig r |] hss jeeees November ,..) 6°52| 138] 4°48) 185] 2°94/ 3:24|! 2°20) 4°55| 2°47| 2°27] 3°70] 162) December ...) 3°35] 3°91] 3°39] 2°25] 3:21] 2°30|/ 1°63] 5:00] 3°95] 3°74]| 2°57] 2:60) Totals ...... 36°59 | 34°42] 36°73] 33°75 27°43 | 30°56 || 23°64] 36°41 | 23°89] 24°21]| 25°05] 36°26 | WALES, ON THE RAINFALL OF THE BRITISH ISLES, 201 Division XI.—Monmovin, Wates, AND THE IsLanps (continued), ONTGOMERY. || CARDIGAN. Rapnor. MerIonetu. Fuint. CARNnaryon. Carno Aberystwith Rhayader Dolgelly, Maes-y-dre Hawarden Beddgelert y gin Brithdin. et : isha 1 ft. Oin. 1 ft. O in. 2 ft. O in. 1 ft. 6 in. 5 ft. O in. 0 ft. 4in. 3 ft. O in. 550 ft. 42 ft. 880 ft. 500 ft. 400 ft. 270 ft. 264 ft. > aa 1870. | 1871. || 1870.| 1871. || 1870.| 1871. |} 1870.| 1871. || 1870.| 1871.) 1870.| 1871. || 1870.| 1871 in. in. in. in. in. in. in. in. in. in. in. in. 2°67] 3°95]| 449] 3°79]| 4:74] 6°43 1°88 86] 2°32] 2°29 || 12°30] 8:17 2°48] 2°47|| 3°92) 4°88] 7°62] 790]/ ‘90) 1°73] 1°33) 2°07/) 4°74] 17°38 2216) || Seu) 2°79| 148 5°68] 4°60 2803) | SISTA em 85) 1s 7°79| 880 2227) 3002 89] 615 3°88) 5°76 Lepalp eae || Saeyel a eAb ie 608} gt 11 1°37 75 2°73 *98 4°66] 1°17 1°34] 10} 02} 1°56 8:00] 2°70 Te52)| 2°74: £90)|='373 2°65| 2°or|| 4°31} 2°67 *78| 280]) 4:82] 4°35 3°29] 5°50) 198) 6:04} 2°05) 7°47 "37| 3°54) °58} 3°23|| 2°58) 16°33 3°42] 2°96 2°00| 2°97 3767/1 © 93°53 I'4t TOF) 2°32 I'02 4°67| 5°69 3°32| 2°76|| 3°11} 4°15] 4°45] 4°35|/ 1:76] 2°97] 190] 4:29|| 840/ 5°96 11°53| 5x1 || 12°23| 6°89 || 16:72] 8°82 5°48] 4°53) 4°41] 4°38]| 22°92] 14:09 640} 3°01 3°85| 1°24|| 8:82] 2°30 3°56] 1°43] 2°60} 161} 10°58] 5°38 3°43 | 2°26 2°46] 2°23 6°78 | 6°33 | 2°20} 1°53] 2°88] 1°59 8°70} 12°93 44°56! 36°76) 41°35 | 43°93 || 71°72 | 60°67 || 22°85 | 24°63 | 23°29 | 28:22 || 101758 |110°89 Div. XI.—Monwmovrn, SCOTLAND, Warns, &c. (continued). Division XII.—Sovrnern Covnrins. Sark. ALDERNEY. Wiartown. KIRKCUDBRIGHT. Dunrrits, Alderney. | South Cairn. || Little Ross. | Carsphairn. Cargen. Drumlanrig. 10 ft. Oin. 1 ft. 4in. 3 ft. 3in. 3 ft. 10 in. 0 ft. 4in. 0 ft. 6 in. 48 ft. 209 ft. 150 ft. 574 ft. 80 ft. 191 ft. 1870.| 1871.} 1870.| 1871. || 1870.| 1871.| 1870. | 1871.| 1870.| 1871. || 1870.| 1871. in. in. in. in. in. in. in. in. in. in. in. in. 1°56| 3°38] 835} 5°05|| 2:40) 1°46) Go2z} 4°67| 5:29) 3°92|| 4°40} 5:00 rar} 2°75] 885] 895|| 213) 4°30] 7°30] 5°71] 5:20] 590]] 6:20) 5:00 "72 69] 3°00] 2°85]) x14] ror] 2°20] 518] 129] 3°47 1°60 *g0 M 48| 2742] 5°65) 8:20 *60)|) e35goil- 52°70}. 5 1G6ile srs6n | 4533 2:20} azo f ; lis 42} 4°85] 2°05 1°67 *50| 4°15| 1°29] 4°68] I'co 3°90 “90 : a 706] 1°96] 3°95| 2°40]! 3°77] 3:16] 184} 5:19] 40] 2718 I°70)}, «3720 ? 3°83 1°30] 2°70] 4°05} 5°25 77 |, 2:85 |. U3n|, 4°58)" 1716). 4:83)|| 2:coleeaRo W5r| roz|| x45| 210) 2°90] 3°10]]/ 131} 3°37] 4175] 4°39] 2°14] 3702} "II| 3°80 1'69| 4°97 *99| 4°35] 630] 2°80|| 212] 3126) 5°31) 2°24| 4:06] 2°60} 4:40] I2¢ 520] 4'12|| 4:20] 3°52] 8:10) 4°80]| 4°41| 3°53] 12°19] 5°50} 856] 400] 7°50] 4:70 2°62| 1°32|| 1°78] 3°47[° 4°05] 7°15 || 2°58] 2°33] 3°35] 483) 232] 340]| 280] 2:90 3°24| 2°57|| 4°95| 1742] 2°20] 3°55|| 2°05] 3°03| 3°20] 8°67] 2:26; 5°89|) 2:00) 6:30 | See eee ee Lae ities [OSE fv deed | 24°33 | 31°32 || 21°05 | 27°18] 62°25] 5615 || 22°95 | 27°60) 51°33] 57°41 | 39°97| 44°54)| 38°81) 41°90 Div. XII.—Sournury Counrius (continued), REPORT—1872, SCOTLAND. Division XIII.—Sovru-Eastern Covuntizs. Dumrates (continued). Roxsureu. SELKIRK. PrEBLes. Berwick. || Happreron. : Silverbut Hall 5 : piss i . Height of | Wanlockhead. Hawick, || Bowhill. Reservoir, Thirlestane. | East Lint Rain-gauge oo Penicuick. above ae | | Ground ...... O ft. 4in. ‘Eft. O in. 11 ft. Oin. || Oft. Gin. 0 ft. 3in. 0 ft. Sin. Sea-level......) 1330 ft. 512 ft. 537 ft. 1150 ft. 558 ft. 90 ft. 1870. | 1871.} 1870.| 1871. || 1870.| 1871. |] 1870.| 1871. || 1870.) 1871. |) 1870.| 1871. in. in. in. in. in. in. in. in. in. in. in. in. January 5166] G10] 2°58] 4181 3°34] 2°03]) 240] 2°55]/ 240] 1:60 27.9) | ais 9 February ...| 6'94| 8°84] 2°38] 4191 2°89} 3°50]/ 2°95] 3°05]| 160] 4rol] 2:94] 2:26 Miarchivss. 2 2°66| 6:26| 303} 2:00|/ 112] 2°13]/ 140] I'g0|} roo] 450] 4°13 "33 | ipril: amass 3°07| 4°28 *96| 4°08 80] 3°89 *70| 4°50 05] 3°80 22] 4°69) Mia > card: :.. 5°36] os} 1°93] 1:06]! 2°63] 1:05]/ 1760} 4r10]| 1°80 "90 257 | aueees June si... 2°02 | 2°02] 1°86) 2°87]) 2:10] 3°37]] 2:90] 2:20]] 2:35] 3:10]} 1°68] 3:22 Why Gatees: 189] 5°84] 2:04] 3:02]! 325] 3°16|| x20] 3:15 *g0] 3°50 193 | 992827 August ...... T90] 5°59] 154] 2°10]) 1°43) 2°74]/ 100] 3°55]! 80] 150]! 69} 1:27 September...) 4°59} 3°35] 1:97/ 1°95|| 2:10] 1°73|| 2°45] 2:25]] 1-60 3°00 ||. 2°26] 2°43] October ...... 795| 467] 3°35] 245]! 3°79] 2°83]| 3°65/ 215]] 3:50] 2-70l] 2:45] 2°55 November ...} 4°50} 2°53] 1°71] 2'cg|| 1'08| 192 115} 4°60]] 1°50] 3°70 *380) 3°16 December ...| 2°77} g:21| 1°64| 3°16 || 2°53] 2:88|| 2:25 3°30] 3:90] 2'20]/ 3°84] 14 Totals ..... 49°31) 59°74] 22°99) 28°50]! 25°06) 31°23 || 23°65] 34°30] 22°40] 31°60 || 19°30] 256 Division XIV.—Sovrn- Western Covytrns (continued), eee eee LANARK (continued). Ayr. RENFREW. . Hill End : Mansfield, || Nither Place, fae House Blibtic, Girvan. Auchendrane. Taree Mesias: Greenock. above Ground ...... 7 ft. Oin. 1 ft. Oin, 2 ft. 3 in. O ft. 6 in. 0 ft. 6 in O ft. 6 in, Sea-level...... 620 ft. 187 ft. 96 ft. 30 ft. 360 ft 64 ft. 1870. | 1871. || 1870.| 1871.) 1870.| 1871.| 1870.| 1871.|| 1870.| 1871.|.1870.| 1871. in. in. in. in, in. in. in. in. in. in. in. in. January...... 2°52) 2°54 || 475] 4°36] 3°54) 3°99] 5°80] 3°30|| 2°00] 5:00 7733] 5°90 February ...} 1°55} 3°83 5°14) 714) 2°45) 4°53] 4°90] 7°50]] 3°75] 5°75] 5:64] 8°65 March™.:.... 88| 2°22 2°06| 4714] 143] 4:04] 00] 4'50/} 1°50 4°50] 1°30| 61m BANDYIL sMecine ss 4 V'24} 2°12]) 2:29] 2°97} 2°11) 3°34} I*g0] 3°30] 2:25] 4:25] 2°55] 5-14 Nay Wee <03 2a 92, |®<2-30 |) Mr02) eas 15 *85| 5:00 70|/ 5°13] 125| 5°64! 160 PUNE 2.2.85! 2°49 "46 3°88} 2°57) 240} 2°13] Igo} I'g90 2°06| 2°00] 91] 3°73 italy Wetoeeens a 2°53) 4°98|| 181] 2°84] 2°02) 3°55) 2°60] 3°40||/ 212| 4c50] 25x 3°51] August ...... 79] 3°24|/° 2706) 4745} 2°06/ 5°15] 2°30] 3:40] 2-25 \6 o| 2771 449% September... | 2°66] 1°76] 3°70} 2°52} 3°87) 2°08] 3:90| 2°60]| 4:37 5 445] 2°32 October...... 3°31} 2°16)| 12°29] 4°03} 4°99| 2°65] 5°60) 3°80}] 5°38] 3°50 715| 662] November ...| 1°Sg| 1°23 3°28| 6:03] 2°55} 2°80} 2:80} 400]! 2:50 4°25)| 922733) | Be December ...J 1°92] 1°67|| 2°85] 5°76] 2-05] 5:06 3°10) 440]! 3°38] 638] 4°62] gr51 Dotals .....: 24°13 | 26°53 || 45°81 | 47°83 | 33°22) 40°17] 40°80| 42°80] 36°69| 47°88 47:00} 62°3 Se a a a a ae Ee Is Glencorse. 0 ft. 6 in. 787 ft. 27°72) 34°35 Balloch Castle. Division XIII.—Sovuru- Eastern Counrizs (continued). - SCOTLAND. ON THE RAINFALL OF THE BRITISH ISLES, 203 Division XIV.—Sovru-WEstERN Countiss, Epinsurcu. LANARK. Charlotte-sq.,}| Newmains, Auchinraith, Glasgow ate Inveresk. Edinburgh. Douglas. Hamilton. Observatory. Bailliestown. 2 ft. Oin. 0 ft. 6 in. 0 ft. 4in. 4 ft. 9 in. O ft. Lin. 0 ft. 3 in. GO ft. 230 ft. 783 ft. 150 ft. 180 ft. 230 ft. 1871. | 1870. 1871.} 1870. | 1871.| 1870. | 1871. | 1870.) 1871.| 1870. 1871. in. in. in. in. in. in. in. in. «| in. in. in. 2°70| 1°67 125| 3°48] 449) 2°89] 2°65] 418) 3:38) 544) 3°77 2°90| 2°05 2°41} 5°66| 3°27) 2°05) 2°75) 633] 4°86) 231 4°63 1°85] 1°00 ro7} 108) 4°54 63) 1°94 *93| 3705] 10g.) 3°26 4°60) °27 4'55| 147] 3°04] ‘80] 302} 1°46) 442) 129) 5°52 79 a “SaaS E7 61) 2°18 7 8l li 5 9°2G) Barer 2h. ee (mn Maenay 2°35| 180 190] 2°75| 3°29] 145) 1°75 1°84| 2°72| 2°49] 3716 310] 1°26 2°80] 175) 499} 167) 4°05| 2°52) 4°51) 3°71 5°82 2°65 "93 2°56| 2°48) 429| 1703] 6'55| 1°76) 3°66) 1:25] 4°82 3°05| 1°77 2°55) 4°09| 180] 2°32] 1°43] 3°71) 160) 4°37) 2°12 Se ies = 73 2°45) 4°75| 428] 2°95} 1°97| 461) 310) 477| 3700 4°70 85 287] 2°76] 211} 1795) 2°40) 1°84) 3°27| 2°53) 3°57 3720} 2°40 163} 178) 5°38) 4°84] 2°73, 2°87) 4°85) 3°20) 4°59 16°50 26°87| 35°22| 42'09| 21'76| 32°02 | 35°25 | 40°54) 36°17 45°69 Division XV.—West Mipnanp Counties. DuMBARTON. STIRLING. Bure. ARGYLL. : Devaar : Arddarock, Polmaise ; Rhinns of Eallabus Loch Long. Garden. Pladda. = Islay. Islay. town. 0 ft. 10 in. O ft. Zin, 3 ft. 3 in. 3 ft. 4 in. 3 ft. Oin. 1 ft. Oin. 80 ft. 12 ft. | 55 ft. 75 ft. 74 ft. 67 ft. 1871. | 1870. 1871. | 1870. | 1871. || 1870. | 1871. 1870.| 1871.| 1870.| 1871. in. in. ims, || ik in. in. in. in. in. in. in. 4°23) 7°19 gi60 || ee28Q |) ATE |p 9°70) 1 6°43 b+ 208 2°78| 3°39| 4°16 681] 7°51 4°60|| 2°38]. 676|| 508) 716) 1°76] 3°70). 3°30 5°16 3790] 2°30 280 *75| I'92 V81} 3°41] 122] 2°58) 1°25) 3°79 511} 3°06 4°30) 131] 3°76]) 1°79] 447] 168] 3°37) 2°58] 3°95 wes) < 6°13 1°30]| 2°75 $37 ee Al28 80} 1°84 °87| 9:09). x3 2°03| 3°07 2°00 || 2°08| 2°48 |) 2°45 *8g| 20g} 1°80] 2:81} 1°53 3°98) 3°14 4°10 3°01 3°35 216} 3°18 be 2°37 | 525 2°61) 4°94 S21) 1°32 3°20), 5°33) 3°34) 824) 2°72 77| 227) 139) 2°79 1°89] 66 2°50}| 2°21] 2°71 3°91| 219} 4°05] 1°72| 5°00) 3°91 5°33| 10°38 310 |) 4°25] 210] 8°52} 4:05) 5°28) 3°57) 813) 5°13 19} 316 2°60!) 1°77] 2°46|| 3131] 5°05) 31°32] 3°03] 2°62 4°67 5'60| 5°83 4:00 || 2°90] 3°82|) 2°07) 4°70} IO 3°82 | 9°69.) 496 59°15 | 71°40 38°10 || 27°63| 37°18 || 38°32) 45°0c| 25°42 | 34°76 | 39°80] 45°52 204 REPORT—1872, SCOTLAND. Division XV.—Wesr Mipianp Countrzs (continued). ARGYLL (continued), Height of |Castle Toward. ache Callton Mor. le ry Lismore. Hynish ; Rain-gauge ee a above eee ee ad eee nee eee! | ee Ground ...... 4 ft. Oin. Oft. 3 in. 4 ft. 6 in. 0 ft. lin. Bii Ain, \4| sees Sea-level...... 65 ft. 16 ft. 65 ft. 30 ft. 0 dm Me 1870. | 1871.) 1870. | 1871.] 1870.} 1871.} 1870.| 1871.| 1870.| 1871.| 1870.| 1871 in. |* in. in. in. in. in. in. in. in. in. in. in. January...... 3°99| 3°39] 3°20] 360] gor! 445] 3°00} 3:00] 1°69] 4:24] 7°61 S04 February ...| 5°53] 6°51} 11°50] 5°40 6°30} 6'45| 3°50] 2°00] 2°47] 4°38] gtox 6°53 March absena 1°33] 4°04] 140] 5°40] 1°32] 4°23 *50| I'50 64.) S10] 2°85] 7°87 FAROE i aueioasis =e 248) 5°43] 4:40| 2°70] 2°39] 3°69] 3:00 *50| 241] 3°84) 4°45) 3°74 WENO .aosaBee 3°98| 2°44] 5°30] 1°20] 4°59] 2°17| 700} 00] 3°34 *93)| 16°27 |) 65 NGM... 2°32} 2°65) 2°80) 1°90] 3°09] 2°70] 2°50] 2°00] 2°36 1°64 | £27316 i233 DULY: | tone =e 2°68! 3°94) 5:10} 5°00] 671] 5°81] 2°00] Stoo} 3°13 3°64) 4°16] 4758 August ...... 2°03) 4°00] 2°20] 4°00] 1°40] 3°29] 2°00] 6:00} 1°39] 1°48 *76i)) TRS September...| 3°80] 1°61] 5'90| 1°80} 4°70 I°97| 5°00] 100} 4°36] 4°38] 8:07] 3°74 October ...... 621] 4°69|/ 6°60] 5700] gt19|} 4°85] goo] 1°50} 6:48] 2°35| 8:17 5°90 | November...) 2°52] 3°72} 1°90] 5°70] 2°61] 516] 2°50] 6:00] 1°64 3°94| 4°63] 8:32 December ...} 4°19] 5°68) 3:00] g:00] 3°95] 7°51| 2°00] 12°00] 1°76] 4:86 5°77 | <3o7g Totals ...... 41°06 | 48°10} 53°30] 50°70] 50°26] 52°28) 42°00] 41°50] 31°67] 35°78 59°53| 57°38 Division XVI.—East Miptanp Countries (continued). Perr (continued). : J Auchterarder Stronvar, Loch), . . a Strath-tay, mee a Loch Katrine.) rouse. Farn Head, | 2tinity Gask.| Scone Palace. Logione above oe Ground ...... 0 ft. 6 in. 2 ft. 3 in. 0 {t. 4 in. 0 ft. 1 in. 2 ft. 6 in. 1 ft. Oin. Sea-level...... 830 ft. 162 ft. 460 ft. 133 ft. 86 ft. 313 ft. 1870. | 1871.) 1870.) 1871.| 1870.} 1871.| 1870.) 1871.| 1870.| 1871.|} 1870.| 1871. in. in. in. in. in. in. in. in. in. in. January 500] 60] 2°15] 2°75] 5:03] 8:05] 2°78] 2:26] 2:05| 2-31 February 9°80] 940] 3°70} 3°20] 14°10} 7°32] 3:16] 3°68] 2:80] 3:95 March ...... 1°30] 6:20 #70) |ee2eg0!\8027A3\|| 87-90 230)| Wa30 "56| 1°50 April Wass 2- 3°60} 4°80 170) 5520) 421011" S45 70 28} 5°30 24.) 4°28 Misty ec Guwed 7°30| 1°80} 2°20 88i5)) 86°10)!" (2:10\| “2:00 *6o} 1°45 "33 ume sesesces 1°80] 2°60 *90| 1°25] 2°55] 2°92] roo} 1°85 *96| 2°22 ily, tecteenc: 2°90} 6:00] 1°30] 3°50) 2°60] 8-05] 1°65} 4°30| 1:20] 4rro August ...... 1'20| 640] 1°30] 2°80 *70| §75| 140] 3:30] T:04] 2°07 September...) 660] 240] 2:10] 1°40) 7°32] 2:28] 3:00] 230] 2:12] 1°85 October ......! 11°30] 8°70] 4:30] 3°75] 10°25| 7°95] 3°76] 4:10] = 3°30| 3°56 November ...| 2°90| 6°40 7.0)| @azrOO)|) eege2 ih ners *90| 2°20] 1°42| 2°16 December ...| 3°70] 9:20] 4:00] 2°85] 3:90] 12°30] 4°36] 2°70| 4:25 "84 Totals ...... 57°49| 70°00} 24°05] 31°85) 61°33] 75°57] 24°59] 34°69] 21°39| 29°67 y. XV.—(continued). Araytu (continued). CLACKMANNAN. Corran Ardnamur- Loch Eil. chan. Pollan. 0 ft. 4in. 3 ft. 6 in. O ft. 6 in, 14 ft.? 82 ft. 174 ft. 1870. | 1871.| 1870.) 1871.] 1870.| 1871. in. in. in, in. in. 6°65| 2°37) 3°64] 3°60] 2°94 9°40] 1°49] 2°71] 3°80] 6°23 7°95 BY eave: CIS a3 185] 82) xi17t 1°36) 6°43 1°65) 2°09] 130} 3°53] 104 1°05] I-91 "Sit £ F298) 02°92 5°95| 3°20] 3°30} 1°88) 3°93 770| 4°84) 2°93) 1°42] 2°64 B25 4:95) 2329 Ft) 2°74) BOS e2O)| E59 424), 2004. 3°85} 2°94) 428] 2°35) 3°56 BS) 273° | 67225 3°07) 3°49 65°25] 30°98 | 37°61] 31°61 | 41°99 Division X VI.—Easr Mrpnanp Counties (continued). Forrar. Montrose SCOTLAND. ON THE RAINFALL OF THE BRITISH ISLES. Division XVI.—Easr Mipranp Countiks. | Kiyross. || Fire, | Pert. | | | | | | err ce | Nookton. | Kippenross. Deanston. | | O ft. 10 in. 0 ft. 6 in. O ft. 4 in. Oft. 4in oot Mae aan 80 ft. 100 ft. 130 ft. 1870. | 1871. | 1870. | 1871. || 1870.| 1871.| 1870.} 1871. pee | el ee eee oe in. in. | in. in. || in. in, in. in. 2°20] 2°30/| 2°21] 43r\| 4°30| 2°50] 3°94] 2°93 100] 4°40]/ 2°00] 3°89|| 260] 4:10} 4°23] 5°70 *50| 1°80 77i\ee TOG)llee LO) te 245 *st| 3°48 1501) 8 5330 Wife! aay, *20| 4°20/ 121] 4°40 1°70 *B0]] 1°72 "90 || 2°20 *45| 2°96] 1°10 T°80)} | 2:30i||) "u91 | 2°32)||F * Too} 2°30), ar7r | ay 80} 4°40 "97| 3°90] x80} 4°20] 2°05] 5°35 PONE ZOEY EOSt |e 223248) eS OHNE SHEO 95) 42% 2°60] 2°20|| 2°47) 1744]| 2°20] 460] 3°15] 1°90 420} 4i2O |) 324 B24) 4-50} | 2530) 5:30) 3°54 T2356) 2970 Pp UF 551 |2 2924.3) |e eis20) |) 2:20); reggie gang 3°990| I30]/ 340] 1°98]| 310] 3'r0| 2°87] 4°30 21°40] 34°10 |] 21°69 | 30°94 || 23°70] 32°40] 30°22] 41°81 Division X VII.—Norru-Eastrern Covntizs. KINCARDINE. The Burn, Brechin. 0 ft. 4 in. 235 ft. 1870. | 1871. in. 1°50 2°40 “47 65 1°47 2°98 4°34 72 2°54 4°92 3°28 574 in. I'Io 3°00 69 5°51 72 1°42 3°21 1°48 2°49 2°78 2°90 1°39 22°15) 28°65] 22°40 26°69} 31°01] 33°74 in. in. 2'20| 1°80 4°00) 4°70 vi *70 *60| 4°40 2°40 *70 *90} 1°80 I°7o| 5°20 *30| 2°50 3:10] 2°00 4°20) 5°40 3°90] 2°60 72) RO 28°70| 33°20 ABERDEEN. Braemar. Aberdeen. Leochel, Cushnie. 1 ft. Oin. O ft. 4in. 3 ft. O in. 1114 ft. 95 ft. 882 ft. 1870. | 1871.| 1870. | 1871.| 1870.| 1871. in. in. in. in. in. in. "80 61} 1°38] 1°30] 41°36] ror 4°40| 3°62| 2°52] 3:42] 4°03] 3°03 °37| 2°73) °83] °38] 143] °70 2°03| 2°65] I'50| 4716] 108] 4:09 2°66] 1:06} 1°36 63) |, 2238 "gI 1'28| 1°90 83) 06} 1°30] 2°50 1°97| 3°74] 3°03} 2°85] 2°72] 4:42 4°79| 2°49 80)|)/a721)|.. 1°80) ees6g 3°68) 3°72) 4191} 1°76] 3°05] 3°30 400} 4°51) 2°55) 3°57) 3°76) 4°08 WAG PP s7O\| 22998" 247.).. 47aaaleeeTG I'95| 1°62} 490] 1°42) §°95| "95 30°38 | 30°35 | 24°00] 25°18) 32°31 pae'sa 206 REPORT—1872, SCOTLAND. Division XVIT.—Norrn-Easrern Counrins (continued). ABERDEEN (continued). Height of Rain-gauge above Ground Sea-level January ...... February March October November ... December ... Division XVIII.—Norru-Wesrern Covnttes. Banrr. Ross anp Cromarry, | 4 ; f Inverinate Ardross pao epee House, Lochbroom. | Cromarty. Castle, \ : "| Loch Alsh. Alness. | 0 ft. 4in. 1 ft. Gin. 3 ft. Oin. 0 ft. 8 in. 3 ft. 4in. 1 ft. Oin. 349 ft. 70 ft. 150 ft. 48 ft. 28 ft. 450 ft. 1870. | 1871. || 1870. | 1871.] 1870.| 1871.] 1870.| 1871.| 1870.) 1871.| 1870.) 1871 in, in, in. in. in. in. in. in. in. in. in. in. 1363/55 1653 36 66] 2°69] 4:25) 4°42] 4rr| 1°52 "70; 2°87| 2°51 3:02] 4°44|| 2°28) x54} m95| 6:53] 16) 4°67 *86| 1°78] 2°06] 3:00 17 3hae 59 98) 9°44] 3°57] G80) 10} 3°95) ‘47]| *54| ‘7o] 47K QAO ie sA' Zo TGA 9e3°O7 1 21778 | o28 |. co44)| Sara | rte ‘77| 2°34) 4:09 1°73 73 I'lg #78)| S4252'| Metco |, ar'58\|| sar | Ox-ep *¥2'|, Hi96 "42 ‘7 bil) yre2s 157 |. otk80) 9475 | o'e'00| seg6 92 | ©3397 || Riez *84.) 2°00 3620) 2°98 || 1:22] 5°42] 3°57] 9°42] 3°62] 3°55| 4140/ 5°99] 199] 4-72 94 22°18 || 2:19)| 93°50] 09°27] -4t29] “2:21 | 93°44. “51; 2°¥0] 2°12] 1°95 232.2) 62822 2°53] 5°61] 3°30] 172] 4°68] 1°76] 1:86] 3°95) 3°37 4°45 $095 | 4212 |]. 2°22)..1°75] 5°80] 9°85] 5:20! 5:04) 1-74 73) 3°61.) (g@e 419] 2°60]! 3:12} 3°30] 2°30] 2°65] 417] 2°69] 392] 1°63] 4:12] 2-80 6°36} I90]] 4'06 796] 3°95] 8:15] 4°88] 5:04] 2°51 54) 4°82) 2°93 29°49 | 28°84 || 23°56] 28°83] 43°95] 58°94] 41°82 | 37°49 | 16°28 | 20°87] 30°80 33°80 Division XVIII. (continued), Height of Rain-gauge above Ground Sea-level January February August September ... October November ... December ... Totals Division XTX.—Norrurrn Counrizs. Ixvervess (continued). SuTHERLAND, Grantown. Laggan. Dunrobin. cia 1 ft. 1 im. 0 ft. 9 in, 0 ft. 8 in. 1 ft. Oin. 712 ft. 821 ft. 6 ft. 35 ft. 1870.) 1871 1870. | 1871.) 1870.) 1871.| 1870.| 1871 in. in. in. in. in, in. in. in. 157| 1°56] 2°41] 494] 2°41) 1°63] 3°00] (1°90) T5441 oeueS8i| eset 3s }Oegahs) W203 | 9525) + 2-80] Sa*6o worn] Sal4 71 P2226 aR on *58| 130] Igo/ 1°80 144| 1783] 4°48) 2:00} 1°32] 3°63] 2°50] 1°70 1°52)) 159) 2062 78 "90 *42| "40 “60 TESgl) > OR Gol meriaa | Paes, BS *80] 1°20 20 2°06| 4°86] 2°02] 3°38 "50| 3°50] 2°09] 3740 2°81) 2°65] 1°82) 3°25 *92| I'S50 *g0| 2°10 2°84.) 4°31| 512] w61] I°95} 2°77| 8:10| 2:60 2°71 | 9 $0051] 0 95339)| 12605 | 92°88) o 25.5 | 2 R250} Sixsbo 5:72)| -Sior |os2to4.|: -1199] 8:42] 2°50 || © Bx80| 2750 3105|| 0127 /) earn || 16234] agr20 *90| 4°00] 2°50 28°26 | 27°27 | 37°69} 32°30] 26°76) 24°75] 35°10 |(22"90) Cape Wrath. 3 ft. 6 in. CAITHNESS. Nosshead. 3 ft. 4 in, 127 ft. 1870. | 1871. 355 ft. ? 1870. | 1871. in. in. 183] 2°85 se a 5) 146] 1°84 3°43} Igt 1°98 84. 1°69 58 241) 5°15 1°34| 320 4°68] 3°16 2°59| 5°06 3°76) 1°38 2°88] 3°80 29°26] 33°12 in. in 1373 ‘60 14} 104 T°03 s 1°64) 2°01 1°66 1°33) 83 67 I’rr| 2°1g 40] 3°19] 2°48) 1°74. 2°30} 1°58 272 | 1265 5°02) 1°45 22'06| 1891 ON THE RAINFALL OF THE BRITISH ISLES. SCOTLAND. Division XVIII.—Norru-Weusturn Counzins (continued). INVERNESS. 207 34°95 | 49°48| 55°40| 7o°10| 25°62) 30°89 | 42°78 | 37°86) 17°91] 20°76 | 33°51) 42°57 ORKNEY. SuETLAND. Pentland (p ieee Sandwick, - Corrimony Ushenish, Culloden | Island Glass, Oronsay. Raasay. Barrahead. | gouth Uist. aS 7 Glen, rquhart. 0 ft. 6 in. 1 ft. 4in. 3 ft. 0 in. Oft. 4 in. 3 ft. Oin, 3 ft. 4in. 0 ft. 6 in. 15 ft. 80 ft. 640 ft. 157 ft. 2 ft. 50 ft. 537 ft. 1870. | 1871.| 1870.| 1871.| 1870.| 1871.| 1870.| 1871.| 1870.| 1871.| 1870.| 1871.| 1870.) 1871. in. in. in. in. in. in. in. in. in. in. in. in. in, 150] 682] 445) 885} m3r} 4°03) 3°02 3°69| 1°56] 1°74] 2°68| 3°34] 3°20] 3°80 W60] 4791] 5°70) 7°55} 1°72) go} 3°03 | 2°29 78 °99| 1°57| 3°60] 2°70} 3°20 2°20) 5°55] 80] 7°35] 00] 2°14) 1°99] 3°30 928) P)rl72)| Soeur | 295427) |, T Songer 510] 1°75} 6:75] 200) I°90} 2°09 6°53) 1°85 "93| 1°96] 3°80] 2°47| 3°50| 1°80 400| 2°34| 5°75]. 215] 2°00 *90| 3700] 114 "74 *4.5\| 22°16) “=re10 "80 "40 3°80| rir} 310) 120] 1°94 *68| 2°82 *95| 1°69 *92| 1°47 65 *70| "90 2°17| §°93| 2°65| 820| 2°30| 3°29] 2°30) 427] 1°33] 4°02) 3°47 6°34| 1°50} 3°30 72| 2°96| 2°10| 4°45] 1°60) 2°98) r'81| 3°64 97 |" $1982) Pexi6A erga 3)|) 190) iaiea §°76| 151| 6:00} 1°75|- 4°49) 2°65] 5°47| 2°39| 2°10) 2°90) 4°95) 2°84] 3°50| 180 4:70| 844] 6:95| 8:80) 3°96| 3°54} 4°65) 519] 2°32| ror] 3°83] sar} 240) 3-00 I'30| 2°90| 4°10] 8:00] 2:00] 3°12) 3°84] 3°28] 2:23) 2°35| 3°46/ 325) 180) I'10 2°10} 5:26| 6:05] 9°80} 1°40} 3°57| 4°32] 5°87] 2°98 88) 2°37] 4°92] 3'r0| 6°60 26°60| 34°80 Serie, Manse, | Sumburghead.| Bressay. East Yell. 3ft.3in. || Oft. Gin. 2 ft. O in. 3 ft. 4in. O ft. 4 in. 1 ft. Oin. 72 ft. 50 ft. 78 ft. 265 ft. 60 ft. 178 ft. 870.| 1871.| 1870.) 1871. || 1870.| 1871.| 1870.| 1871.|/ 1870.| 1871.) 1870.| 1871.| 1870.| 1871 in. in, in. in. in. in. in. in. in. in, in. in in. aro} 1°65] 4165|| 2°30] 3°30] 2°31] 4'65]) 1°62| 2°66| 2t7| 241] 3°15] 5:90 45| 2°60] r00| 2°57]) 210) 3°30] 2°92) 4'40|/ 2°98) 3°39] 2°07| 5§'93| 3°83] 8:co *50| 1°80 65) PO Earl = T500)) "e T°S5Ol/eeie25)\i2?30 DOT 6 © 2"45)) 2 r252)) 0926 | gens eater 230} 160| 1°86] 1r25|| 3:co| 1730) 2°77] 1°74 VI4| 2°3 237 1)| 2°57 | 4997) aan r60} rro| 3152 87|| 70 [Ocl PeteO7 0 rxtr2:|\" Siko7 86) 151 *70| 14] 2°09 “80 "20 69 *47|| x°00 “sant tie70 33 °75\\) 2703) SFair3 | rar2.|* 8a) eos 120] 3°90 *56| 2°78] “4o| 2°30] 4°33] 2°85 93 "52 36) 1°66) x17) 2°34 “30| 2°90 "73| 2°731] *70] 3°30} IX) 2°93]/ *96| 3°04] 1°30] 4°25] 1°88] 2°33 W335) 170} 2°86] 2°59] 3°80] 2:70) 3°30) 2°85) rq} 2°23] x51] grog] 1°75] 2°56 P90} 150) 197) 1°57] 2°50/ 2°30] 3°17) 3°98] 2°96) 4:16) 3:16] 4°33) 2°43] 647 B03) 200/ 2°08) 2°71) 3°80) 90| 3°67) 4°04) 3°43] 325] 3°58) 2°40] 4-49| 5°83 : 1"90 : 7°30 | 3°60} 5°52| 3°98 | 3°00) 4175| 3°46) 317] 4°94] 6:94 29°60 | 26°40| 30°72 | 32°17 | 21'1g| 23°69] 24°48) 33°84) 32°42] 50°88 208 REPORT—1872. IRELAND. Division XX,.—Munsrer. Cork. Kerry. Warerrorp, | Cuare. Cork, Height of Queen’s Fermoy. Pik aoe Waterford. Killaloe. Rain-gauge College. Why above Ground ...... 6 ft. O in 4 ft. 0 in 4 ft. Oin, 4ft.Oin. | 5 ft. Oin, Sea-level...... 65 ft. 114 ft 100 ft. 60 ft. 123 ft. 1870. | 1871.| 1870.| 1871. |) 1870. 1871. | 1870. | 1871. | 1870. in. in. in. in. || in. in. | in. in. in. in. January ...... 4°76] 4°92] 3°50] °4°32 3°37 |. 7750 )|), 74°75 |) 48a || 295775) wang February ...| 4°39] 447] 3°07] 4°55|| 4°67| 6'78|| 3:26] 3:93]/ 3°02] 3°70 March .2:5.. Di2h eocOAi! be2iGe || wi2*28)|| 4996/3778 || 2:99) |-o2rr8)||\) O74) meonRs Avor) |snesttee: r14| 4°48 ‘on: |4 3°19 || 5°63}, 22481), 2821) sacar || e207 | eaano2 May) Reetet.e- 2°38 3655 2716 66 || 4°95 06 || 3°50 "7111 3°93 99 GUNG) Peeakiess: eV i ed) "73 Bao *26i| 915-70 )||) W291) 43-74: CO iD || garmin Daly fingers. Tor | 4°67 *g1| 3°80 281 7°53 | '47| 5°02 || 1°30] 5°99 August ...... T“60)| H2705)| rer6)| 97-53 55] 5°14} : : : ‘ September... 3:44] 4°59| 2°75| 2°87|| 12°68] 3798 | October ...... 6°70] 3°43] 618] 3°82]] 16°51] 7°05 || November ...| 3°33} 5°06] 2°23] 1°92]] 8°66] 4°43] December ...| 3°98] 4°20] 2°89] 3752 1°53| 829, Totals ...... 35°61 | 45°38 | 29°09] 35°56 || 69:01] 62°72 Div. XXII, LEIster. Fenagh ~ House, Bagnalstown. 1 ft. 5 in. 340 ft. | 1871.] 1870. | 1871. in, CARLOW. 412} 3°48 2°33u aegis 2°34) 2°04 VOI | 3°57 196 . 106 ? 1°53] 445 Division XXII.—Connaveur (continued). ENNISKILLEN. Division X XIII.—Uzusrer. ANTRIM. Roscommon. Suico. Cavan. Mount . Height of Holywell. Doo Castle. Shannon, Eee ; Rain-gauge Sligo. ; above Ground ...... 5 ft. 6 in. 1 ft. O in. 4 ft. 5 in 0 ft. 9 in. Sea-level......| ...sseaeee oe | eee nes 70 ft 208 ft. 1870. | 1871. |) 1870. | 1871. | 1870.| 1871. 0. | 1871. in. in. in. in. in. in. in. in. January ...... 3°28] 2:98]] 3°31] 4°57] 3°32] 4111 4°19] 4°33 February ...| 2°74] 3°62|| 4:12] 3°86] 2:26] 334] 2°51] 3°36 Merch) esse: Go| sees5 || 223i ematOOsligasO | gh 2T KaarchA || ien83 \ oval) mae sbane 146| 3°22|| x72) 4°98) 1°75| 3°51] 316) 3°3x NUE), ga Reese 1'68| 1°34|/ 3°30] 4142] 2°86] 1:06} agi "92 PUNO Marae ep e=s w81| 4°27 TI53)| 8 ZrO t| weere2 e277 to ea oe le 09 sfalliy* eeane-se 212| 5°49)| 1°66) 5°64| x86) 653] 165] 7°82 August ...... 2°48| 2°48 *86| 2°41] 3°05| 2°66) 1°24) 2°46 September...| 3°32] 1'95]] 3°59] 2°21] 4:07] 1°55] 3°35| 2°03 October ......| 5:92] 2°21|| 9792] 3°67| ro:12| 3:21] 7°60] 2759 November ...) 1°93] 1°92|| 2°56] 2°57| 3:25] 3°26) 1°86] 1°78 | December . 2°90) I'99|| 3°41] 3°60) 45] 3°35] 3°22] 2752 Totals ......] 31°22 | 33°62 | 38:21] 40°84) 42°21] 38°50] 32°45 | 36°04 Florence | Court. 11 ft. 0 in. | 300 ft. | 1870. | 1871. in, in. 486) 4°49 5°38) 4°75 1°44] 3°93 2°01] 4°56 3°62.)/: soe 1°23 |, exeon || '27] 8:22 1°38) 3°37 || 3°74] 2°19 | |} 12°15] 3°57 2°64) 4°24 | 435} 3°89 42°97 46°29 | Aghalee, Lurgan. 1 ft. O in. 105 ft. 1870.| 1871. in. in. 2°95| 3°33 I'gt| 2°84 146 1°45 120] 2°86, 2'18 c 1'06 2° 252.5 5a 145) 3° 2°29) 2° 757 |e ) 1°57] 2 i 2°97 2° 28°86 | Cartow (@ontinued). ownes Hill, Carlow. 1 ft. Oin. 291 ft. ON THE RAINFALL OF THE BRITISH ISLES. IRELAND. 209 Sidi. Division XXII.— Division XXT.—Lerysrer (continued). Gaetan QueeEn’s Co. || Krne’s Co. WIckELow. Duin. GaALway. F Galway, Portarlington.|| Tullamore. wee Black Rock. | Cregg Park. Queen’s ways College. | DEsSE dy Bi ES eae ee 1 ft, 2 in. 3 ft. 0 in. 5 ft. 0 in. 29 ft. O in. 3 ft. 0 in. 8 ft. 2 in. 240 ft. 235 ft. 250 ft. 90 ft. 130 ft. 30 ft. 1870.| 1871. || 1870.| 1871.) 1870.) 1871. || 1870. | 1871.] 1870.| 1871.| 1870.| 1871 in. in. in. in} i.) | ane in. in. in. innate in. 2°83] 3°43|/ 281] 3:43/] 420] 3:79|| 2°59] 3:76] 3°82] 3°60] 44x] 6:44 1°75] 2°00// 3182] a14]| 3°36] 3:98|| 2°68] 2°63] 2°97] 281) 2°72! 4°78 2°28] 1°46 2°67] 1°75 Z°15 | 172 2°12 68) I22,| 3°02), 145) eon 93) 3°17)/ 98} 400|] 65] 3°47|| 65] 2°86] 181} 498} 261) 3°44 2°15 "63 || 2°12 AISA ee 2a =32)\| 1°20 16] 3°79 86] 4°36) 1°28 86] 2°33 *69| 2°71 48] 3°08 "JO| 2°54 98] 3°97) 145] 3°50 117} 5°62] x07] G629|| 46) grr] 68] 5-94] 1°33] 4°95] 3°43] 620 161| 1°97/| 1:49] 1°70|| 2:20] 1:24|| 1°96]} 110] 199] 214] 3°29] 3°64 2°95) 160|/ 2°66] r19]} 2°64] 4°46 122) e4tO|, 3602 D305 se52 | eae 6°54} 2°83] 554] 2:29]! 8:64] 348]| 664] 284] 6:09] 3°48] 9°69] 220 104} 1°65 65] 144/} 219] 481i] 54) r41I 89] 146) 4°57} 1°38 1°93] 1°82)) 2°36] 1-70/| 2°90] 1°79|| 2°94 *99] 210] 4guS| 3°65) 244 26°04} 28°51 || 24°86} 29°09 || 33°14.| 33°25 || 25°02| 28°11] 30°01 | 36°84] 44°84] 39°69 Antrim (continued). trim, it. O in. 50 ft. Tey este in. 22| 3718 174) 2°64 ‘91 | 1°63 86] 3°90 2°38] 1°03 169! 1°94 60] ° 6:29 pany | © 1°78 B36) 3°14 7°60! 2°57 175 | . 2°52 B50)| 2°37 p54) 32°73 Division XXITI.—Uzsrer (continued). Lonponperry.|| Tyrone. Donzaat. Belfast, Queen’s | Carrickfergus.|| Londonderry. || Omagh. Letterkenny. | Dungloe. College. 7 ft. 4in 1 ft. 0 in. 0 ft. 6 in. 1 ft. Oin. 1 ft. 8 in. O ft. 6 in. 68 ft 18 ft. 80 ft. 280 ft. 108 ft. 10 ft. 1870. | 1871. | 1870.| 1871. |) 1870. | 1871. } 1870. | 1871. || 1870. | 1871.| 1870.| 1871 in. in. in. in. in. thay fh abayeee|artne in. in. in. in. 2°44) 4°38] 3°37| 3:41|| 3°00] 4°44] 2°87] 411]! 3°93] 5°70] 2°73) 4°37 BeCmeeaaanee asin “3:67 Zee Ge 2ckO'| | 2:Gr |= 2rde AsHr | srs e336 240 T4ol) 1°78 })) 1:27 ||) 20x TOR | as O5:) 89) 2:04]/ 1°77) 448) 168) 4°37 Aig eso 2. lia T28.9)|) Ato} 2°20] 4°12 7 Oi pge7.5 2126.1 \ Asai2) | 28g) gases BOA eS | e125 8 87 |] 2°04 16 || 2°84 67|| 3:16] 129] 2°10) 1°23 P20 oD O7 ) t20) 1°53 1°'70| 2°40 Tosh ie as 2°70| 3°82] 2°02] 2°84 161} 3°86] 2:27] s:00|| 1°95] G20] 2:06] §:79]] 182) 943] 2°14) 5°77 2°09) 2°83 *57| 3°97|| 2°40] 2°80|| 215] 219|] 2°33) 3°50] 2°78) 229 143| 3°39| 2°23| 27541] 4°53] 3°78|| 3°25] 1°67]) 5:90] 2°78] 470) 3°63 9°92 3°08] 8-31] 2-44]] 980} 1°63]) 7°70) 2°49} 1105) 4°74] 8°50) 4r32 103| 1°74| 1°36] 2°99|| 2°50] 340] 2°15] 1°47/| 4°49| 4°50) 4°02) 3°58 2°39| x84] 2°96] 2-45|| 3°55| 2°70|| 233) 2°52 || 4°90] 4°47) 2°86) 5°53 30°14| 3r-91| 30°70| 35°05 || 37°27| 37°18|| 32°06) 31°43 || 49°42) 52°63/ 39°18] 43°65 _ 4 210 REPORT—1872. Report of the Committee, consisting of the Rev. Dr. Ginsgure, W. Hepwortu Drxon, Rev. Dr. Tristram, F.R.S., General CuEsnry, Rey. Professor Rawiinson, and Joun A. Tinneé, appointed for the purpose of undertaking a Geographical Exploration of the Country of Moab. Report on the Exploration of Southern Moab. By Cunistran D. Gryssure, LL.D. Tue expedition left London on Wednesday, January 10th, 1872, and arrived at Jaffa on Monday, January 22nd, about eleven o’clock in the morning. The party consisted of Dr. Ginsburg, Dr. Tristram, and Mr. Johnson. Mr. Klein, the original discoverer of the Moabite Stone, arranged to join them at Jerusalem. The object of the expedition was to get to Moab as soon as possible; it was determined not to tarry in the Holy Land, how- ever much some of us felt tempted to explore the country. We therefore proceeded, at 3.30 p.m. on the same day, to Ramleh, taking Lydda on our way to Jerusalem. Carly in the morning of the following day (January 23rd) we started for Jerusalem over Beth-Horon, and reached the sacred city in the dark. After waiting six days at Jerusalem for an escort, and making the neces- sary preparations, we left for Hebron January 30th, at 10 a.m., where we arrived about six o’clock in the evening of the same day. Here we engaged Abou Dachouk, the Sheikh of the Jehalin tribe, to conduct us safely to Kerak. He entrusted his old uncle, Abou Salama, to head the escort; and we left Hebron at 1.30 p.m. on Thursday, February lst. As it had been determined to enter Moab by the south, we now made our way to Engedi, and arrived at Um Ghazelat at 5.30 p.m. Though this place is halfway between Hebron and Engedi almost in a straight line, and though the old Abou Salama, our guide (who, like his an- cestors, was born and brought up in this neighbourhood), has acted as a guide to former explorers, yet he does not seem to have mentioned Um Ghazelat to those few travellers who have come this way before to explore the basin of the Dead Sea, nor can it be found in the most recent maps of Syria. We pitched our tents for the night at this supposed new place, near the encampment of the Raabneh tribe. At 10.5 a.m. on Friday (February 2nd) we left for Engedi, where we arrived at' 4.30 p.m. Here we encamped near the beach of the Dead Sea, and opposite the Moab shore and mountains, to which we were making our way. We left Engedi in the afternoon of the following day, which was Saturday, and determined to pitch our tents for Sunday at Sebbeh. Between Engedi and Sebbeh we passed on the shore of the Dead Sea the following four Wadys :—Wady Ghar, which is close to Engedi, and which we erossed at 12.37 p.m.; this Wady, which our old Sheikh solemnly assured us was Ghar, is marked both in Van de Velde’s and in Lynch’s maps as fyreyeh. The next is Wady Chobrah, which, according to Mr. Klein’s most painstaking cross-questioning, we found to be the proper spelling, and not Khuberah, as it is spelled in Van de Velde’s map; this Wady, which we reached at 2 P.m., is an hour and twenty-three minutes from the former one, The third Wady, which is an hour’s distance from the second, and which is marked in Van de Velde as Wady Halil, we were positively assured is Wady Mochrath; whilst the fourth Wady, which is about forty minutes’ distance from the third, and which has no name at all in Van de Velde, we were told GEOGRAPHICAL EXPLORATION OF MOAB. 211 is Nemriyeh. The distance between this Wady and Wady Seyal, where we camped, we did in a little less than an hour. Having spent Sunday, February 4th, at Sebbeh, and explored the ruins of the famous fort, we started on Monday, at 7.45 a.m., for the Wady Zuweirah, where we arrived at 3.30 p.m., and encamped for the night. In the seven hours and three quarters which it took us to get from Wady Seyal to the Wady Zuweirah, we passed no less than ten Wadys, respectively called (1) Wady Sebbeh, (2) Wady el Kattar, (3) Wady Havhav, (4) Wady Senin, (5) Rabbat el Jumuz, (6) Wady el Kitter, (7) Wady Mersed, (8) Wady Chasrurah, (9) Wady um Berrek, and (10) Wady Nejd. Of these ten Wadys, which are almost equidistant, only six are laid down in Van de Velde’s map; and even of these six the names of three only cor- respond, the names of two out of the three being reversed (viz. Nos. 4 and 5 in this Report), whilst the names of the other three (viz. Um el Bedun, Wady Hatrura, and Um Baghek) are not to be found. It may be here remarked that Wady Nemriyeh, which, according to our guide, is on the south of Sebbeh, is in Van de Velde’s map on the north, that the cliffs come up quite close to the sea between Wadys 8 and 9, leaving no beach whatever, and that we had here to make our way over the rocks. This fact is not pointed out in Van de Velde’s map. Being determined to cross the dangerous Valley of Salt early in the day, we left the Zuweirah at 6 a.m. on Tuesday, February 6th. Before leaving this remarkable spot we were determined to explore it, as well as the range of salt mountains which is known by the name of Khafhm or Jebel Usdum. It will be remembered that this is the spot marked in De Saulcy’s map, as well as in the map of Palestine used in our British schools, as the site of Sodom ; indeed De Sanley declares that he saw here “the ruins of a build- ing which was anciently a part of Sodom.” Anxious as some of our party were to see the relics of the doomed city, a careful inspection of the heap of stones referred to left no doubt upon the mind that they are the remains of a mediseval square tower, which was erected here to protect the labourers in the salt mountains who carried on traffic with Hebron and other towns. Between the Zuweirah and our entering the Valley of Salt we passed the marvellously torn and rent salt mountain, as well as three Wadys. Our Sheikh, Abou Salama (the brother of the very man who was De Saulcy’s guide, and who gave him such minute information about the ruins of Sodom), could not even tell us the name of any of the Wadys. One of these had actually bored a tunnel through the salt mountain, and thus made a remark- able hole through the cave in Jebel Usdum. The beach now was nothing less than a soft slimy mud. The distance between the Wady Zuweirah and the extreme point of the Es Sabkah, where we began crossing it, is an hour and a half. At 7.30 we entered upon the margin of the barren flats of back- water. After marching for about three hours knee-deep in slush, and ecross- ing seven drains, some of which were dry and some still draining, we arrived in the front of the Saphia at 10.3 a.m. Here our troubles began. Seeing our cavalcade crossing the Salt valley, the Moabites must have thought that we were fair game for plunder, or that We were come to invade their homesteads. On approaching the Saphia, we - found three tribes arrayed against us in front of the wood, beyond a narrow intervening stream. The grotesque mob, as we neared them, uttered shrieks, yells, and war cries, firing off their few guns, and refusing to let us enter their territory. Abou Salama, our old Sheikh, and Daud, our dragoman, with a few of our Bedouins, bravely jumped over the stream. The horses of Q2 212 REPORT—1872. the old Sheikh and the young dragoman fell into the water, and the riders were soon seen rolling on the ground and struggling with their enemies. One of our Bedouins was lying prostrate on the ground, and bleeding pro- fusely. After a few minutes the Sheikh and the dragoman were again on their legs and parleying with their assailants, assuring them with solemn oaths that we had not come to invade the country. We were at last allowed to cross, and were led by these bands of robbers into the Saphia, where a place of encampment was assigned to us about three miles towards the north. After pitching our tents we clearly saw that our safety consisted in keep- ing together, and not straying singly into the wood, since these robbers were lurking behind the trees and bushes for prey. The three tribes who occupied the Saphia, and who now considered us fair game, are the Bene Attia, the Maaz, and the Warroney. We were, in fact, virtually prisoners, inasmuch as we did not venture to go beyond our tents; and we therefore deemed it more prudent to remain within our encampment the rest of the day, which was Tuesday, February 6th. In the mean time the robbers secretly des- patched messengers to the Mugelly of Kerak to inform him that a batch of European magnates were in the Saphia, and that they too should come and have their share out of us. The son of the Mugelly Sheikh of Kerak, as it might be supposed, immediately came over and declared that we were in the hands of cut-throats and robbers, and that he came to save us from them. From the respect and deference which the Saphia tribes paid him we believed his declarations, and indeed began to feel ourselyes more secure and at liberty. We now determined to explore the Saphia and the extensive ruins in the neighbourhood. ‘To do this we had to negotiate with the Saphia robbers, not only for permission but for escort. Their demands were exorbitant. As we decided to see what could be seen here we made the best bargain we could ; and about 11 a.m., February 7th, we started on our explorations, ac- companied by eight of the Saphia princes on horseback. Our direction was south-west of the Saphia, and we rode through a forest of acacia, thickets of tamarisk, and dwarf palms, till we came to very extensive ruins. These ruins, according to our guides, are divided into three parts; one is called Sheikh Isa (Jesus), the other Kasur el Bashaira, and the third the Mashnaka (hanging-place). In the second of these ruins we saw corpses of women lying about. After carefully inspecting the ruins, which cover between one and two miles of the ground, it may be inferred that though the bulk of those which still rise to a considerable height above the ground are decidedly remains of medieval sugar-mills and other buildings of that period, the foundations, and indeed the larger portion of the hewn stones strewn about, are as decidedly partly relics of buildings of the Roman period and partly the remains of edi- fices of a much older date than the Roman occupation of this district. They most probably exhibit the Moabite fortified frontier, both against the Jews on the west of the Dead Sea and against the Edomites on the east and south-- east. The fact that this is the southern frontier of Moab suggested another con- clusion, which elucidates a geographical remark in the Pentateuch on the limits of Moab that is greatly obscured, and is perfectly without meaning in the authorized version. In Numbers xxi. 12, 13, we are told that the Israelites removed from Zared, “and pitched on the other side of Arnon, which is in the wilderness that cometh out of the coasts of the Amorites.” This verse therefore gives the Arnon as the northern limit of Moab, thus GEOGRAPHICAL EXPLORATION OF MOAB. 2138 assuring the Israelites that all north of the Arnon up to Heshbon is to be theirs. In confirmation of this statement, the sacred writer quotes in the verse immediately following the declaration made respecting the frontiers of Moab from “The Book of the Wars of Jehovah,” wherein the whole extent of Moab from south to north is most minutely fixed, and the two boundaries are ;distinctly specified, viz. the southern boundary is Vahab in Suphah [Saphia], and the brooks of Arnon the northern boundary. Completely surrounded by the escort of these savages, we left our encamp- ment at 8 a.m. As our tents were pitched almost in the centre of this oasis, we passed through, for about two miles, a forest of acacia, tamarisk, dwarf palms, and reeds on the shores of the Dead Sea, bearing north-north-east. At about 8.20 we reached the ruins of Um el Hashib, and about 8.40 we erossed the Wady Korcha. - The name of this Wady disclosed a remarkable fact, which Dr. Ginsburg believes will henceforth definitely settle a geographical point mentioned in the famous inscription on the Moabite Stone. On this triumphal pillar King Mesha tells us, in line 3, that he erected the monument in question at Korcha. In lines 21, 24, 25 we are told that this king built and greatly fortified Korcha after the expulsion of the Jews from Northern Moab; and though the word is treated as a proper name, and hence is without the article, yet epigraphists of great distinction maintain that the word, according to its form, cannot be a proper name, and therefore is the Plat-land or Market. Now the existence of a Wady named Korcha, spelled in exactly the same way as on the inscription, leaves it beyond the shadow of a doubt that Korcha on the Moabite Stone is the proper name of a town. When, in the sequel, we come to Dibon, we may be able to show the position of this town. Going on still due north we came (circa 9.2 A.w.) in about twenty-two minutes from Wady Korcha to Wady Mirwacha, and in an hour and a quarter more reached the ruins of Numeira (7. ¢. circa 10.15). These ruins are in extent more than half a mile, and cover a surface of uneven ground. The stones of ancient buildings, which are strewn about in all directions, are mostly very large, about a foot and a half in diameter, but roughly cut. Some foundations of buildings, as well as the remains of a quadrangular wall, are distinctly discernible. The great geographical interest of this place arises from the fact that it figures on the maps of the few eminent travellers who have explored this region as the site of two remarkable places mentioned in the Bible. Thus Irby and Mangles (p. 448), as well as Lynch (p. 345), identify it with the ancient Zoar, to which Lot and his daughters fled for shelter at the destruction of Sodom; whilst De Sauley marks it as the site of Zeboim, which was destroyed at the same time as Sodom. The locality, however, as well as the name, correspond far more with the ancient Nimrim mentioned in Isaiah xy. 6, and Jeremiah xlyiii. 24, than with either of these hypotheses. Marching due north for about three quarters of an hour, we entered a thicket of thorny trees and bushes, and then crossed Wady Azzal at 11.30 a.m., leaving a fringe of reeds near the beach of the Dead Sea to our left. We continued our march north-east, ascending a hill and leaving the promontory or peninsula of Lissan somewhat to our left. We now ascended the southern portion of the ravine through which the Wady Drah flows into the Dead Sea, and crossed the Wady at about 2 p.m. Our journey was now almost due east, ascending all along by the side of the ravine; and at 3.30 we reached the top of the hill Drah, about 600 feet above the Dead Sea. The scene of our encampment here was most charming. To our left was the deep ravine 214 REPORT—1872, through which the Wady Kerak flows, with a perfect oasis on its slopes and with a Bedouin encampment. To our right there was a perpendicular moun- tain rising above us, on the summit of which are the ruins of an ancient tower, which was evidently designed to guard the pass to Kerak. At our back was the peninsula of El Lissan, and in front of us were the steep moun- tains of Moab, through the defiles and over the giddy heights of which we had to wind our way to Kerak. By the lurid light of our bivouac fires this remarkable spot looked sublimely lonely. The Mugelly with great cunning selected this place as best serving his purpose. We retired to rest, little dreaming what we should have to wake to. In order to show how secure we were under his protection, and to lull us to sleep pleasantly, the Mugelly got up a sham fight with the Saphia robbers, charging them with mean behaviour towards us, and threatening to stab them, for which purpose he actually drew out his dagger. As it was an affair between themselves, quarrelling about the money we gave them to buy them- selves a lamb for supper, we did not interfere, but went to sleep as soon as the deafening noise of these villains subsided, and rose early to resume our journey to Kerak, which was only four hours and a half distant. It was here that the true character of the young Mugelly showed itself, and that we learned to our bitter cost why he urged us to dismiss our Jehalin escort, and why he adroitly selected this lonely spot for our encampment. No sooner did he perceive that we had begun to strike our tents than he demanded £70, and declared that he would not allow us to proceed unless the money was forthcoming. He at last consented to take 25 napoleons; and at about 8 a.m. we started on our journey. What might happen to us at Kerak when lodged in the clutches of this vagabond was more than any of us dared to think of. We tried to comfort ourselves with the fact that one of the gang was a Christian, and that he might be of help to us when the worst came to the worst. We proceeded on our journey notin a very good humour for exploring. We continued ascending a ridge of wild mountains, called Akabat Charaza, crossed the Wady Charaza, and came to the ruins called El Kabo (7. e. the cave), about 1000 feet above the Dead Sea (circa 9 a.m.). Here we were told a Christian Sheikh lived in olden days, who exacted tri- bute from all travellers to or from Kerak. The hill on the right of El Kabo is called Bothéneh, whilst the hill more to the north still is called Elmanzar (v.e. watch-tower), Ascending still higher we climbed a ferruginous hill, called Jebel el Hadid, passed Wady Umeshanan at 9.30, Wady Ruseis, with the spring called Ayin Ruseis, at 11.15, reached the plateau of Omsidré at 12, and descended to the bottom of Wady Kerak at 12.40. We now began climbing an almost perpendicular zigzag, leading to the summit on which the ruins of this famous fortification, with its enclosed huts, are planted. On our way to Kerak, the Mugelly was very anxious that we should camp outside this vulture’s nest in the deep valley below, which is exceedingly fertile, and where there are ruins of ancient buildings and a sugar-mill. To this we decidedly objected, as we should have been cut off from all communi- cation with the inhabitants, and in that case the vagabond could make any demand upon us without the possibility of our appealing to any one. He had therefore to lead us up to Kerak. The road consists of a very steep terrace on a charming ravine, strewn all over with stones of different shapes and various sizes. These stones being imbedded in the precipitous ascent, form, in fact, crooked steps. So steep is the ascent, that we had to dismount and lead our horses. We reached the top at 1.30 p.m. It was fortunate that we went to examine the place immediately after our GEOGRAPHICAL EXPLORATION OF MOAB 215 arrival; for soon after we returned to our tents the son of the Mugelly, who brought us from the Saphia, came and demanded no less than 600 napoleons, as the remainder of the money for bringing us here and for allowing us to encamp at Kerak. We of course refused to pay any thing, and told him that, although he had extorted 25 napoleons from us, he had no right to act in this hostile manner. Seeing that we were determined not to be bullied out of any more money, he forbade us to leave our tents, and we thus became pri- soners. In this plight we were visited by the Greek catechist, whom Mr, Klein knew. He procured us a messenger, whom we secretly despatched to Jerusalem with a letter to Mr. Moore, the British Consul, informing him that we were prisoners and that 600 napoleons were demanded of us. As it was Saturday we made up our minds to a quiet rest in our tents for two days, which we did not grudge, as we were tired and wearied out with annoyance from the Kerak vagabonds. In the midst of our gloom, however, a ray of light appeared. We heard that Zadam, son of the Sheikh of the Bene Sachar, with whom Mr. Moore the consul had made a contract at Jeru- salem to take us from Kerak to the north of the Arnon, had arrived here, and was the guest of the Mugelly. The old Sheikh, the father of the Mugelly who had plundered us on our way from the Saphia, we had not seen as yet. We were told that he camped three hours from Kerak, that he was a better man than his rascally offspring, and that though “his belly, too, was as large as our tent, his mind was as wide as the ocean.” We therefore sent a messenger to our future protector and guide Zadam, requesting him to come to our tents. At about 12 a.m, the old Sheikh of the Mugelly, with Zadam of the Bene Sachar, and a hoss of Moabite grandees came to pay us avisit. To this old Mugelly Sheikh in conclave we recited our troubles. He at once set us at liberty, and told us we were perfectly free to go where we liked, that his country was our country, and no man should dare to touch us or make any demand of us. _ Our joy was now beyond bounds. We were not only set at liberty without money and without price, but we were told we might go wherever and do whatever we liked. To our further satisfaction we saw the old Sheikh taking his seat on the ground among his magnetes, fifty yards from our tents, with his son opposite him in the ring, and heard him rating the scoundrel as hard and as loud as possible, telling him that he had brought shame and confusion of face upon his old father in the sight of these Consuls (which is the name they give to distinguished foreigners), and dei.anding that the 25 napoleons taken from us should at once be restored. We even heard that the money which had been divided between the chief robber and about a dozen minor scoundrels was actually being collected. Being thus set at liberty, we devoted the rest-of Saturday and the following day to the exploration of this stupen- dous ruin and the town. The following is a sammary of the results :— The very entrance into this ext aordinary ruin of Kerak, or the ‘“ Rock of the Desert” (Petra Deserti), as it was called in the middle ages, is remark- able. It consists of a long and winding passage of about 100 feet through a high ridge of the natural rock, which forms a cavern gate. It is in such a zigzag that we could not see those of our party who were fifteen yards before us. It is surmounted by an illegible Arabic inscription. Looking at it from the summit of the neighbouring mountains which overtop it, Kerak exhibits the form of a rude triangle; whilst from the bottom of the ravine it appears like a.vulture’s nest, constructed on a peak more than 4000 feet above the Dead Sea, 216 REPORT—1872. To understand the plan* of this fortification, it is necessary to bear in mind that the hill, the summit of which contains Kerak, rises on three sides from a deep valley, thus yielding natural buttresses, which, from their im- mense height and perpendicular form, defy any attempt at scaling them. It is only the north-west and south sides which are joined to the neighbouring mountains by crests of rocks; these, therefore, require artificial protection, and it is for this reason that the fortification consists of two distinct parts, viz. the tower on the north-west and the castle on the south. The tower is a large oblong building of immense height, constructed of very huge and neatly cut sandstone. Viewing it from the town, it looks like three out of four skeleton walls of an unfinished edifice, being open towards the defile. It is furnished with galleries and staircases inside the thickness of its walls, putting the different stories of which it consists in communication with each other. It presents its three faces (the circumference of which measures about 131 yards) to the defence of the exterior, and is joined by its two extremities to the town which it was designed to defend. The stones of which it is built have been cut from the side of the rock on which it is erected. By this process the north-western side has not only been separated from its adjoining mountains, but the tower has obtained a very steep but- tress. From the Arabic inscription El Melek—Daher—Bypbars in the central wall, it is called “The Tower of Daher,” or “The Tower of Bybars.” It was within this three-walled tower that we camped, and were imprisoned in our tents. We saw Jerusalem most distinctly from the top of this tower. The castle or fortress on the south, which was designed to defend this side, left by nature unprotected, is in form a long square, widening towards the north, the north face being about 153 yards, the south 87, the east 218, and the west 240, thus making a circumference of about 698 yards. It is separated from the city on the north by a wide ditch, and is defended on the south by an immense reservoir, which is flanked by an enormous ditch, more than 98 feet wide, cut in the rock. A rampart, with galleries stretching across the length of the enclosure of the castle, divides it into two courts, viz. a lower court towards the east, and a higher court towards the west. In the eastern or lower court is a chapel, with nave of 82 feet long, four windows, two in each side, and ending in a semicircular arch. There is a staircase in the thickness of the north wall, which leads to the platform on the top of the edifice. Irby and Mangles have noticed remains of large fresco- paintings, one apparently representing a king in armour, another the mar- tyrdom of a saint who has his bowels twisted out, as well as an imperfect inscription in Gothic letters (p. 364). But with the exception of the inscrip- tion nothing is now to be seen. ‘This court also contains the dungeon. In the angle of the western extremity of the higher court is the gate of the castle, which leads, through a long and narrow passage, to two other doors furnished with portcullis and complicated defences. These had to be passed before entrance could be obtained into the enclosure. The court con- tains numerous cisterns and immense magazines of five or six stories high, which are now partly dilapidated. This castle was built about a.v. 1143 by Payen, who was cup-bearer to the King of Jerusalem, and who received Kerak as a fief after the execution of Knight Romanus. * For a sketch of the plan of Kerak, as well as for an able treatise and some verbal com- munications on the same subject, according to which I have been enabled to correct and supplement my rough notes, I tender my best thanks to M. Mauss, the learned architect of the Duc de Luyne’s expedition to the east of the Dead Sea. For the working out of the plan which was exhibited I am indebted to my wife.—C, D, Ginspura, GEOGRAPHICAL EXPLORATION OF MOAB, 217 Between the Tower of Bybars on the north end and the castle on the south, there are ruins of numcrous buildings as well as an immense reservoir. The plateau on which the town is built measures in its greatest length from north to south 852 yards, and in width from east to west 776 yards. Taking it as a rude triangle, the north-east face of the rampart measures about 1028 yards, the south face 868 yards, and the west face 732, making a total of 2628 yards. In other words, the plateau of the rock on which Kerak is built is not only more than 4000 feet above the Dead Sea, but is surrounded by a rampart more than a mile and a half in circumference, ex- clusive of the tower on the north and the castle on the south. But though the fortifications are of the crusading period, some of the ruins in the town, and of the materials used in the construction of the modern dwellings, are decidedly relics of the Roman occupation of this place. These houses, which are some distance from the fortifications, are, as a rule, under the ground. They exhibit a very extraordinary appearance at a distance, since little more than the outlines of squares are visible above the ground. Dr. Ginsburg rode over several of them without perceiving that he was on the top of human residences. On going or descending into one of them, he found it consisted of one large room only, and had a few arches thrown across it, on which were the rafters. In this house, which was occupied by a rela- tive of the Sheikh of Kerak, were the bases of four ancient columns, with a Mosaic pavement in the centre, of which the occupant made a circular hearth, with a raised rim around it. A fire was burning on it; and as there was no hole in the roof to serve as a vent, the whole room was full of smoke, so much so that he could not remain there more than a few minutes, much as he wished to examine the place. There were also raised recesses in the room, serving as a bed and as receptacles for corn. Part of the room also was set apart for the horse, and the goats too were admitted. here is not a single dwelling-place among the hundreds of houses with a window. The population of Kerak is about 8000, about 6000 Mussulmans and 1600 Greek Christians. The former count about 2000 muskets, and the latter from about 500 to 600. After a minute inspection and examination of the ruins of the place, Dr. Ginsburg could discover no trace whatever to justify us in marking Kerak on our maps as the Kir Moab or the Kir Haraseth of the Bible. We were now determined to make the best of our time; and haying heard that the Sheikh of the Mugelly, who appeared as our second deliverer, was likely to disappoint us, we endeavoured to see as much as possible. We therefore started early on the following day accompanied by two horsemen, nephews of the Sheikh, to survey the neighbourhood of Kerak. We rode to the south of the town over magnificent ridges, down rugged and steep ravines, and across beautiful highland country from 8 a.m. to 5.30 P.M. We first came to the place called Gelameh el Sapela, from which Ibrahim Pasha bombarded the town. At 9.15, still travelling $.8.E., we reached the first ruin of Kirjathaim, which is on a hill. The stones which mark the basis of the walls are now in a different position from what they originally were, and distinctly show that the traces of the buildings which they indicate are of a much later date, probably of the crusading period. As the summit of the hill is only about 1000 yards in circumference, and as the ruins on the slope around do not extend very far down, the town must originally have been small. Still the immense stones which are strewn about in all directions, and the extensive cayes on the ridges, show that it was in olden days a very strong and im- 218 5 REPORT—1872, portant place. There are terraces running down at regular intervals to the bottom of the hill, At 9.20 we reached the sister hill, on which the second part of Kirjathaim stood. Its ruins are almost exactly like those on the other hill. And as the terraces here like those there descend all around, the rings of which they consist, as a matter of course, becoming wider and wider as they near the bottom, the last terraces of the two hills meet at the foot, and so connect the two parts of the town. For this reason the place was called Kirjathaim = “ the double-towned.” In each part we saw a deep well, with thoroughly cemented walls, capable of holding a very large quantity of water. As the crow ilies, Kirjathaim does not seem more than ten minutes from Kerak. At 9.30 we left Kirjathaim, and in less than ten minutes we reached a place called Kirbath Nulet, and in about a quarter of an hour after (9.45) we came to Kirbath Aziza. Here we found an old wine-press cut in the rock, and on the other side of the ruin we saw an enormous well. A very little further on we came to Kirbath Nukad, and at 10.10 to Chorba Chaviya. We then reached (at 10.40) a tremendous naturel cavern, called Gava, and got to Mochra at 10.53, This is a very extensive ruin, and has some remarkable cisterns, caverns, and other remains of former glory rarely seen in other places. The most interesting part of this place, however, is in its bearing on the history or geography of Moab as recently disclosed on the Moabite Stone, inasmuch as it supplies one of the two missing places mentioned on this Triumphal Pillar. In lines 13 and 14 of the inscription, Mesha, king of Moab, tells us that after capturing Ataroth and slaying its inhabitants, “ the men of Gad who dwelled in it from time of yore,” he repeopled the place with “the men of Mochrath.” The context plainly shows that these men must have been faithful subjects upon whom the king could rely, and that hence their dwelling-place was south of the Arnon; but-as far as our know- ledge goes, no such place has hitherto been identified. There can therefore be hardly any doubt that this is the place. Within five minutes of the above ruin (10.57) we came to a place in ruins called Gel-gul. After an hour and a quarter (12.7) we reached Mode, where we saw a Roman mile-stone. The inscription was so defaced that we could not decipher in which reign it was set up. At 1.25 we passed the Wady Medin. On our way back we examined the ruin Chorbath Theniah, which is close to Kerak. It is an extensive ruin, and it is rather remarkable that so large a fortification and town should have been erected so near the for- midable forts of Kerak. It was well that we had made use of our liberty thus to examine the neighbouring country ; for on our return we found the old Sheikh with his retinue of sons, cousins, nephews, brothers, and officials sitting in council around and within our tent. He hcard that we were to leave Kerak soon ; and as he wanted a pretext to plunder us, he told us he had been informed that we had sent a messenger to Jerusalem to report his son’s conduct. The fact is that the Greek priest, who for some reason or other expected money from us, and of course was disappointed, got to know that his catechist had secretly pro- cured us a messenger, and reported to the Mugelly Sheikh that we had sent a letter to Jerusalem. What harm this could have done to the old Sheikh was a mystery, since he pretended to repudiate his son’s robbery. The motive, however, was apparent. In spite of all his cunning devices to conceal it, we saw perfectly well that he wanted to extort money from us, and that he must do it at once. This pretended deliverer of ours therefore suddenly changed GEOGRAPHIGAL EXPLORATION OF MOAB. 219 into an insulted enemy. He declared in the midst of his people in our face, that he cared neither for the Governor of Nabulus nor for the Pashas of all the East, nor for the Consuls at Jerusalem, and that he was determined to send us back to the Saphia to the robbers, from whom he now said his son had delivered us. The young Mugelly had therefore no more made his face black by his conduct to us at the Drah as the old rascal declared before, but rendered us unspeakable service by saving our property and our lives. This was now the story of the old Mugelly Sheikh, and to this we had to address ourselves. Our feelings may easily be imagined when we found our professed friend suddenly changed into as great a robber as his son. The Bene Sachar chief who came to Kerak to fetch us told us that it all meant money, and that we must make up our minds to submit to another extortion. The question was therefore discussed what would satisfy the old vagabond. We decided to give him twenty napoleons and his brother five napoleons, and with this he was satisfied. With feelings of great relief we left the old ruined castle, congratulating ourselves that we had at last actually escaped from this fiery furnace. But we had not gone more than 300 yards when a very violent rain commenced, accompanied by a terrific hailstorm. The horses refused to proceed, and we had to return to take shelter behind the walls of the Greek church. Ina few minutes we were wet to the skin, and it seemed that even the elements conspired against us to keep us at Kerak. After waiting for an hour and a half behind the walls and among the tombs in this drenching flood, we made a fresh start at 12.30. The anxiety of the muleteers to get away was so great that they would not allow the storm to stop them, and had gone on without us. Our joy in leaving, which was now brightened by a little sunshine, made us forget that we had tre- mendous ravines to descend and precipitous heights to climb of thousands of feet. It was only when we were actually facing these giddy heights and depths that we began to think how their natural difficulties were now en- hanced by the heavy rain. However, we got through without any further accident than some of the mules falling down and upsetting the luggage, which created a Babel of swearing and such an incessant shouting and cla- mouring amongst the Arabs as only those can realize who have ever had the misfortune to hear it. On our way to Rabba, after ascending the next height, we passed along a beautiful highland, which might be made exceedingly fertile by a little cul- tivation; but these Bedouins prefer plunder to work, and, only sow that which they absolutely require for themselves and cattle. The whole journey from Kerak to Rabba took us three hours and a half. We passed through Chorbath Rakin, a small ruin about an hour from Kerak, Bether, and Min- char. Whatever these places may have been in olden days, at present only large scattered stones and the bases of walls remain to show that at all events some of the buildings were strong and capable of defence. At four o’clock in the afternoon we reached Rabba. This is supposed to be Ar, the ancient capital of Moab (Deut. ii. 9, 29). We camped on the site of an ancient pool, about 50 by 60 yards, and about 21 feet deep. There were three large caverns in the walls, which were a godsend to us; for it was pouring rain on our arrival here, and these caves afforded shelter to us and our horses whilst the tents were being pitched. Between our camp and the ruins of Rabba there was about a quarter of a mile, and there were two more pdéols from which the ancient city derived its chief water-supply. As the rain continued we could not do more than inspect 220 . REPORT—1872, the ruins before nightfall; but early in the morning Dr. Ginsburg and Mr. Klein went to examine them more closely. Unlike Kerak, Kirjathaim, and other ancient places, the ruins of Rabba, which are about a mile and a half - or two miles in circumference, are situated almost on a level, with the ex- ception of one part, which is on a very low hill. On the northern side are the remains of an old temple, with several columns still standing. There are on all sides caverns, large and small, cisterns of various dimensions, and wells of all sorts, which show that the place in its entirety must have been of great importance. There are, moreover, scattered among the ruins, large blocks of basalt, which are hewn into smooth stones for use, and which are evidently of much older date than the bulk of the ruins. It was here they saw a basalt slab, of almost exactly the same dimensions as the celebrated Moabite Stone, which had evidently been prepared for an inscription, but which, for some reason, had been left uninscribed. Several others of smaller size were also seen, which, from their slabby appearance, were apparently intended for tablets. These ancient relics afford every op- portunity to the dealers in Moab and Jerusalem, whose cupidity has been roused by the discovery of the Moabite Stone, to supply the demands of the market, The impression that was formed of the ruins of Rabba is, that though there are among them many vestiges of the Roman period, such as pillars, cisterns, extensive roads, &c., there are very few relics of an older date. To examine Rabba thoroughly, as it ought to be done, one should remain on the spot, and work quietly for at least a week, turn up all the important stones, and in- vestigate and measure all the various pools, cisterns, and caverns. This, however, we could not do. But after a close examination of the place and its surroundings, they came to the conclusion that Rabba is not the ancient Ar, the antiquated form of IR, or AR Moab, as it is stated on the most recent maps. Rabba is almost in the centre of Southern Moab, whilst the Scripture Ar Moab was on the confines of the Arnon, and marked the ex- treme northern limit of the trans-Arnonic Moab, Vahab in the Saphia de- fining the southern frontier (comp. Deut. 11, 36; Joshua xiii. 16; Numb. xxii. 36, and zbid. xxi. 18 and 14), The Greek name Areopolis was first given to the ancient Ar Moab on the Arnon, and afterwards, when Ar Moab was destroyed by an earthquake (comp. St. Jerome on Isaiah xy.), it was transferred to the modern Rabba. We left Rabba at 8.25 (Feb. 15th) on Thursday. At 9.30, travelling N.N.E., we came to a place called Kasr Rabba (7. e. the Palace of Rabba). The ruins here, though small, are exceedingly massive. The stones of which the palace was built are enormously large; they are bevelled, and somewhat resemble those of the old wailing-place at Jerusalem. The bases and cor- nices of columns which lie about on the ground measure 4 feet 8 inches in diameter. The fact that in many parts of the shattered walls the bevelled part of the stones was turned the wrong way, shows that the buildings have been shaken by a violent earthquake. In leaving Kasr Rabba at 9.55 we saw, at a distance to the left, ruins on a hill, which are called Shichan. On the greater part of the way to these ruins, the old Roman road is still most distinctly traceable. Whilst some of our party were marching with the mules to the Arnon, we galloped to Shi- chan, which we reached at 11.20. It is 4700 feet above the Dead Sea, and has a very remarkable cistern on its summit. The distance between Kasr Rabba and Shichan is about 8 miles. In descending the summit we found ourselves for at least a mile and a half on regular terraces, which had eyi- dently been most carefully cultivated in olden days.: GEOGRAPHICAL EXPLORATION OF MOAB. 221 On leaving this place at 11.35, and marching to the Arnon, the change of the soil was extraordinarily sudden. From the fertile ground around these - ruins we all at once came upon a most dreary wilderness, which was only relieved by tremendous holes in the ground, and by dried-up and stunted bushes. It was not till we came close to the verge of the Arnon that signs of fertility began to show themselves. We reached this awful rayine at 1.55 p.m. The southern side, though not as perpendicular and as grand as the descent at Engedi, is exceedingly steep, being 2150 feet deep. It took us fully an hour and a half before we reached the stream at the bottom at 3.30. All the way down the traces of the old Roman road and unfinished Roman mile- stones are to be noticed. The stream is narrow and rapid, and to the right of the descent are still to be seen the ruins of two arches of the bridge, which, however, in its present form, is not older than the time of the Crusades. The cliff at the northern ascent is 1900 feet high. As the road extends over a wider ground, it is on the whole not so steep. It took, however, quite as long a time to ascend it as the descent on the southern side occupied. - Here, where the maps put the ancient Aroer, Dr. Ginsburg and Mr. Klein left Dr. Tristram and his friends. A messenger had arrived from Jerusalem with the sad tidings of the dangerous illness of Mr. Klein’s eldest child. He at once decided to return to Jerusalem, which was perfectly natural. Mr. Klein was the only one who could talk with the Arabs, and we were almost entirely dependent upon him for the information from the Bedouins. The Arabs pronounce the same word differently; and apart from a thorough knowledge of the language in all its various provincialisms, it requires great tact to obtain the necessary information from them. Mr. Klein, with his complete mastery of the language, and especially his intimate acquaintance with the ways, manners, and customs of the Arabs, not only knows how to get information out of them (a tact which he acquired by twenty years’ resi- dence among and intercourse with them), but, above all, he understands how to test the correctness of the information by a series of direct and indirect cross-questioning, which is quite an Eastern art. As it appeared to Dr. Ginsburg that Mr. Klein was thus an essential member of the expedition, he determined to return with him. Dr. Ginsburg continues :-— - We left the Arnon at 7.30 a.m., February 16th; travelling due north, almost all the way on the remains of the old Roman road, and passing the imaginary site of the Biblical Aroer, we came to the ruins which go by the name Diban at 8 a.m., 7. e. in about half an hour. From the fact that the famous Moabite Stone was discovered here, I devoted some time to the ex- amination of the place. The whole of this once celebrated stronghold is in ruins; there is not a single hut to be found on the spot. The circumference of the ground on which the ruins lie prostrate is at least a mile and a half. Like Kirjathaim in the south of the Arnon, this town was originally built on two hills, the sloping terraces of which joined at the bottom; and by this means the place, which looked at a distance like two distinct cities at the top, was joined into one at the bottom. Notwithstanding its undoubted age, few traces of antiquity are to be seen among the shattered ruins of the walls. The old stones have evidently been used up for later buildings; and it would require a sojourn in the place for at least a fortnight carefully to turn up the foundations and the heaps of ruins to ascertain whether some other yaluable relies are to be discovered here. From a careful inspection of the place in connexion with the ruins not far 222 rerort—1872. off, I am convinced that it is not the site of the ancient Dibon, but of Korcha. My reasons for this conclusion are as follows:—i. In all the eight passages of the Bible wherein the name Dibon occurs (Numb. xxi. 80; xxxii. 3, 34; Josh. xiii. 9,17; Isa. xv. 2; Jer. xlviii. 18, 22), no data are given to fix its exact site. The christening, therefore, of these ruins by the name Diban, on the part of the Arabs, like the naming of many other localities, has been suggested by Biblical explorers. ii. The Moabite triumphal pillar which was found here gives us the direct information that Mesha erected it at Korcha, a city which this monarch built. As no one who will examine the enor- mously heavy fragments of this huge block of basalt, with its delicate inserip- tion, will suppose that it has been brought here intact from another place without the inscribed letters being injured, the spot where it was found must be the site of its original erection. And, ii1., between this place and the stream Valeh, an hour’s distance, there are several old ruins, the names of which our Bedouin guide could not tell. One of these is most probably Dibon. After a careful investigation of this ancient site, we left to cross the north- Arnonic portion of Moab. Our route was now to have been over the upland. Going in a north-westerly direction, we passed several ruins, and crossed the stream Valeh, about an hour from what is called Dibon. From this place, instead of pursuing the usual course, due north over the highland, our Bedouin took us westward, right over the range of mountains to Mayin, or what is sup- posed to be Callirrhoé. In this charming valley, to the hot springs of which Herod the Great resorted during his last illness, we pitched our tents close to the encampment of the Awazim tribe, to whose protection we were recom- mended by Abou Zadam of the Bene Sachar. Early in the morning, February 17th, we left for the Jordan, escorted by Abou Wardy, the Sheikh of the Awazim. He, too, led us across the range of mountains instead of by the usual upland road. The most remarkable and significant part of my experience, bearing on the yalue of the information obtained from the Bedouins, I gained on this part of my journey. In looking at a map of Palestine, it will be seen that this range of mountains has played a most important part in the history of the Jews. From these heights Balak king of Moab, and Balaam the prophet of Baal, beheld the Israelites en- camped on the Plains of Moab. From here Moses the great lawgiver saw the promised land: here he died and was buried. Here we passed across the very spot marked on the maps as Pisgah and Nebo. We had with us, from the Arnon to Mayin or Callirrhoé, a Bedouin who was a native of Northern Moab, the whole extent of which is only about twenty miles in length and as many in width. The fact that he was the only companion of Zadam, the magnate of the Bene Sachar, and that with this chief he was to be our guide for more than a month, sufficiently shows that he was no ordinary man of his tribe. From Mayin again to the Plains of Moab and the Jordan we had with us the Sheikh of the Awazim himself, who was not only born and brought up in the neighbourhood, but is the chief of the whole district. Yet neither the second in command of the Bene Sachar nor even the chief himself of the Awazim could tell us a single name of gorge, valley, mountain, or ruin between Diban and the Jordan. The reason of it is simply this. In Palestine, which has been visited by pilgrims ever since the fourth century, who came in search of the placcs wherein the events connected with the life of our Saviour have transpired, the law of demand and supply has brought to the surface whole regions which would otherwise neyer have been named, Those who came thousands GEOGRAPHICAL EXPLORATION OF MOAB. 223 of miles under the greatest privations to do homage in the birth-place of the Saviour, on the various spots where the greatest of his miracles were per- formed, where he suffered, died, and was buried, were determined to have the scenes. Hence the different sections of the Church, inspired by pious devotion, and aided by the cupidity of the natives, have not only been able to discoyer the place of every event, but to secure for themselves severally a different spot where the same event was enacted. The case, however, is different in Moab. Here no events connected with the life of Christ have taken place. Here no pilgrims have come in search of sites. Very few even of explorers have traversed the country. Hence the natives, who can neither read nor write, and who are dependent for information upon hearsay, have never heard from outsiders what places are wanted, and therefore do not know them, and cannot supply them, Geographical Exploration of Moab. By Rey. H. B. Tristram, FR. Tue expedition for the exploration of the country of Moab, so liberally aided by the grant of the British Association, set out from Jerusalem on the 30th of January. Our party was reinforced by Mr. R. C. Johnson, who proved himself invaluable both as a surveyor and a photographer; Mr. Buxton, not less efficient as a photographer and observer; Mr. Hayne, who devoted him- self with great success to the botany of the country; Mr. Mowbray Trotter, to whose gun we were indebted for many a meal; and the Rey. F. A. Klein, of Jerusalem, the discoverer of the Moabite Stone, whose thorough knowledge of Arabic and of the people and the country rendered him an invaluable member of the party, till suddenly recalled home by a melancholy domestic affliction. We determined to enter the country from the south, as being the most difficult and least known route, our course being by Hebron, Engedi, Masada, or Sebbeh, Jebel Usdum, and thence across the Sebkha, or barren sand-flat, which extends for several miles to the south of the Dead Sea. This we ac- complished with a guard of the Jehalin tribe of Arabs. At the edge of the Sebkha we were on the frontier-line of ancient Moab and Edom; and here we met with some little difficulty from a robber tribe, the Beni Atiyeh, with whom, however, after a faint show of hostilities and a few random shots, we were able to make terms. We found the Ghor es Safieh, which we were able to examine at leisure, very much more extensive southward and eastward than it is marked in the maps. It is, in fact, a fertile belt scarcely raised above the level of the Dead Sea, 16 miles from north to south, and fed by the numerous perennial streams and springs which gush from the lofty sand- stone range that forms the buttress of the Hauts Plateau of Moab. On the heights above the southern extremity are the villages of Tufileh and Feifeh, on the banks of streams, which we were not able to visit. Our exploration of the Safich was carried out under considerable difficulty, as the natives were lawless, and we could only move with an escort of horsemen. However, we were able to ascertain, in our rides with our guards and in several rambles on foot, that there are no remains of importance in the oasis itself. The principal ruins are of some ‘extent, indicating a well-built village, with several fragments of columns and Roman work, called Kasr el Bushireh ; and a little higher up is a tolorably perfect water-mill, and a Saracenic gateway of rather rude construction, belonging apparently to a ruined Khan; it is 224 REPORT—1872. now called “ Mushnekkr,” or “the gallows.” No other ruins could we find. We explored on foot the widest part of the Safieh towards the Dead Sea, on the edge of which a rank vegetation of sedge and reed takes the place of the dense thickets of nubk and dom tree which stud the cultivated plain, here about four miles wide. Leaving the Safieh we proceeded by the route of Irby and Mangles to Draa. The day’s journey led us through every conceivable variety of vegetation and non-vegetation. Leaving the Nahr el Hassan, the great source of fertility to the Safieh, we passed through a scrubby plain, rushes, canebrakes, and finally a bare salt marsh, without a scrap of vegetation to the sea, and a grayelly shelving slope, with scattered gnarled acacias above it; near its commence- ment is a ruined village, Um el Hashib, not far from the Wady Grahhih. The barren plain is fringed by a fetid ditch, well named Mir’whar, or “ stink- ing river,” with salt and offensively smelling liquid. Having crossed the salt plain, we came to the Nahr Hanyir and Nahr Nimeirah, salt streams. At this latter are the mean and almost obliterated ruins of a large place, appa- rently unfortified, and usually marked in the maps as the ancient Nimrim of Seripture. This, however, we have reason to believe is incorrect, as the position is defenceless ; and we were told of ruins higher up near the sources of the stream in the mountains, which still bear the name of *‘ the waters of Nimeirah.” Near them is another Scripture locality, “the brook of the willows,” which is given to the head of the next stream before it leaves the mountains. A little above this lower Nimrim we visited the ruins of a fort, Khirbet es Sheikh, which appears to have been nothing more than a watch-tower to guard the road. After crossing the Nahr es Asal, or Honey River, we began to ascend the shoulder of the Lisan, a mass of barren salt marl, without a trace of life, past or present, and in a few hours reached Dria, generally said to be the an- cient Zoar, after crossing the Wady Weydah, in which the palm-tree is abundant. Drda, though the seat of a bishopric in the time of Eusebius, has left no traces beyond lines of foundations and heaps of sandstone, some of them squared and dressed. But the deep glen on the crest of which the city stood is richly wooded with palm, oleander, and other trees; and its fertile belt can be traced by the eye as far as the Mezraah, a wide, scrubby, tree-dotted plain, opening on the bay to the north of the Lisan, and now covered with the tents of the Beni Atiyeh. This has been traversed by Messrs. Palmer and Drake. From Dréa we ascended to Kerak by the route so well described by Irby and Mangles. A fort, hitherto unnoticed, guards the pass about halfway up, called El Kubboh. The character of the architecture is crusading, and the local tradition makes it the stronghold of a Christian Sheikh. Just to the south of this, the ‘‘ Wady of the Willows” was pointed out tous. We calculated the ascent from Drida to Kerak to be 3720 feet,—Drda, though on the brow of a bold shoulder, being 570 feet below the sea-level, and Kerak 3180 feet above it (barometric). Without pretending to compare the country with Switzerland, and at the risk of incurring the sneers of those who, Judging only by bigness, accuse any one who is enthusiastic on Palestine of “‘ Holy Land on the brain,” any one less prejudiced than these critics will admit the pass to be a magnifi- cent one, and the situation of Kerak to be majestic. It has already been described by Irby and Mangles, and is sufficiently GEOGRAPHICAL EXPLORATION OF MOAB. 225 known to students. The entrance to Kerak is certainly unique, by an arched natural tunnel in the side of a precipitous cliff, out of which the traveller emerges in the midst of the city. The photograph shows this gateway into Kerak. It is needless to describe the extraordinary position of the city and its natural and artificial strength against the resources of medieval or modern Oriental assault. It was undoubtedly the strongest natural fortress in Syria before the introduction of modern artillery—a platform of a triangular shape, each side from 3 to 2 mile in extent, inacessible except by exposed mountain- paths on all sides, save where a neck of land connects it with the adjoining mountains, and this cut through by a wide fosse of 30 feet deep and touch- ing massive walls 18 feet thick above it. The fortifications, Phoenician or Jewish in their lower parts, then Roman, surmounted by the work of Crusaders, are of vast extent and enormous height. The photographs give some idea of the vast labour expended on these works. We found Kerak as little hospitable as have our predecessors in this land. The Mudjilli, though holding a Turkish commission, is practically indepen- dent, and is an unscrupulous, avaricious, and cunning chieftain. We were held as prisoners for some days to ransom, after entering under his son’s safe conduct; but our imprisonment was not severe, though rather costly. On one day, when our keeper relented, we were able to go out with a guard, and ride many miles to survey, while the rest of the party photo- graphed nearer home. Our survey proved very successful in fixing the sites of many ruined places, some of them hitherto unknown by name, and the others erroneously placed in all the existing maps. Our course lay chiefly south for twelve miles, and thence back by a detour to the eastward. Crossing the deep valley of Tziatin, where the soldiers of Ibrahim Pasha were slaughtered in 1844 in attempting to cut their way from the north, we marked the position of Jelam es Sebbha, where Ibrahim Pasha had his camp; and then of Kureitin (evidently an ancient Kiriathain), the remains of twin ancient towns close together, each on alow knoll, This fashion of two adjacent towns with the same name seems to have been very prevalent throughout the whole of Moab. Here we found ourselves on the high tableland which forms the country of Moab, studded thickly in every direction with ruined villages and towns, always situated on gentle swellings—Kirbet Azizeh, Kirbet Nekad, M’hheileh, Howeiyeh, Jubah (on the old Roman road), Mahkhennah (mentioned by Irby), Modeh, Abon Taleb, Mesh’had, and several others. Modech, like Kureitin, has been a twin city, and there is a Roman milestone, unmutilated, close to it, of the date of Antonine. At none of these ruins did we find any water, but wells and cisterns innumerable, from fifty to one hundred in each place, generally one for each house, and oil-presses and wine-presses cut in the rocky slopes. We returned by Madin, more extensive ruins than the others. Here were sarcophagi and sculptured fragments, and house-walls quite perfect, but without a trace of mortar between the dressed stones. We saw, but did not visit, the ruins of Moureyah, Hamad, Suhl, and Nachal, mentioned by Irby. From the Kerak people we obtained a long list of names of ruined sites known to them, upwards of sixty in number, some of which seem the Arabic representatives of Hebrew names. Dimnah (perhaps the Dimon of Isaiah, commonly held to be identical with Dibon), Lubeirah, Sumrah, Yaroud, Betir, Hadadah, Rahun, Zérar, Hhomoud, Azour, and others. In a few days, by the aid of Sheikh Zadam of the Beni Sakkr, we were 1872. R 296 REPORT—1872., able to leave Kerak without the payment of a very heavy ransom (£70 in all), and started for the north. It must be remembered that Kerak is the one inhabited place in the whole country, the only town or village in the vast and once densely peopled region between Hs Salt in Gilead and Shobek, a little village in the ancient Edom. Passing the ruins of Suweiniyeh and Duweineh, after descending from Kerak, and ascending again more than 1000 feet, we rode through the ruins of Rakim and Mikhersit, from which place we followed the Roman road to the ancient Rabbath Moab, now Rabba. These are some of the most extensive and finest ruins in Moab; but the incessant rain prevented our taking any successful photographs. We camped inside an immense Roman tank, 60 yards by 50, and, though filled to a considerable extent with the refuse of the goats which are herded there, still nearly 30 feet deep. The city seems to have been a square, more than a mile each way. One fine temple has some columns and two arches left ; but all else are only broken walls, with long lines of straight narrow streets and countless vaults arched over. The ruins are Roman, but with many carved stones from earlier edifices built in, and many dressed blocks of basalt, telling of a still more ancient city. There are several green mounds covering extensive masses of masonry, which might probably repay excavation. From Rabba we followed the Roman road northward, passing a very perfect little Roman temple, one and a half mile from the city, and soon afterwards a ruined town (the remains of which seem anterior to the Roman occupation), Missdehh, and immediately afterwards Humeitah, the Hammat or “Animah” of Palmer, probably an ancient Ham. Kasr Rabbah, or Beit el Kurm (the house of the vineyards), four miles north of Rabbah, has possessed a magnificent Corinthian temple ; the diameter of the columns, many of which with the frieze are standing, is 4 feet 8 inches. Hence the Roman road divides, one line going towards Shihan, the other, more easterly, to the passage of the Arnon. ‘The former crosses the gentle depression which marks the commencement of the Wady Ghurweh. An easy slope reaches to the top of Jebel Shihan, on the southern side of which, lining the Roman road, are very singular remains, countless small enclosures, fields or gardens, all formed of blocks of basalt, undressed, and no limestone employed; they cover many acres. The road here has been only 15 feet wide. The city itself, on the top of the hill, has been built chiefly of limestone, with very little basalt. The cisterns are numerous and of considerable depth; but they, as well as the wells, are now all dry. Descending by N.E. we passed through the ruins of Balh’ua, and overtook the rest of our party, who had followed the other route. Near the edge of the ravine of the Arnon are the remains of an old fortress, Kirbet Sum’hra, and then Muhatet el Haj, conjectured to be the Jahaz of Scripture, shape- less ruins. The passage of the Arnon has been described by several of our predecessors, who have certainly not exaggerated its magnificence or their fatigues. By our barometers the depth is 2150 feet, and the southern plateau is 200 feet higher than that to the north. The Roman paved way may be frequently traced, as well as the remains of the bridge below. From crest to crest, we computed by triangulation to be about three miles. . The upper part of tue southern side reveals a superficial basaltic stream, which is absent on the north. There are numerous ruined forts all along the Roman causeway. On the northern brow, a mile east of the road, are the ruins of Arar, the ancient GEOGRAPHICAL EXPLORATION OF MOAB, 227 Aroer; and “the city that is in the midst of the river” (Josh. xiii. 16) is no doubt indicated by the remains in the luxuriant strip of semitropical verdure that fringes the Arnon far below it. Here, from the news of a sad domestic affliction, brought to us at Rabbah by a messenger who had been beaten and robbed of the letters by the scouts of the Kerak ruffians, Mr. Klein, to whose aid we are really indebted for the success of our expedition, through his masterly knowledge of the language and his friendship with the Beni Sakkr, was compelled to leave us and return hastily to Jerusalem. He was accompanied by Dr. Ginsburg. From the northern crest of the Arnon bank a good view could be obtained of the general lie of the Wadys which here furrow the high land. The Arnon, or Wady Mojib, is formed a little above where we crossed it by the junction of three ravines of nearly equal height, the northern one named by Zadam Wady Seideh, the name given in all the maps to the central one, and the others Mikhanas and Balhua. A ride of three miles across a dreary highland plain brought us to Dhiban, another double city on two knolls, whose caverns, cisterns, underground store- houses, and semicircular arches present no peculiar features. To the west of both knollsis a little stream, near which the famed monolith was found, and in which water was running. All the surrounding hills are limestone, and there is no basalt except what has been brought here by man. It is need- less to say that no inscribed remains now exist above ground; but we found a very finely dressed basaltic oil-press, with the upper stone lying close to the outer cylinder, by the bank of the stream. 'From Dibon we struck eastward, by the route taken by Messrs. Palmer and Drake, towards Um Rasas. The road lay up a wide depression, which could scarcely be called a valley, known as Kurm Dhiban (the vineyards of Dibon), and continuously for three miles were the traces of the vineyard- ridges across the slopes. These are “the plains of the vineyards” of Judges xi. 33, the route taken by the Amorites after their discomfiture by Jephthah. Rujum Selim, a shapeless inconspicuous heap, is the only ruin on the way from Dibon to Um Rasas. This latter seems placed too far east by Palmer, who has also erroneously marked the Hadj road as touching it, and placed it ten miles too far west—a mistake not to be wondered at when we con- sider the very great difficulties under which Mr. Palmer and Mr. Drake accomplished their visit. A Roman road does, however, touch Um Rasas from Heshbon to the south. Um Rasas was of necessity very hastily examined by our only predecessors, and is of much greater extent than had been imagined. The outline of the city and its walls, apparently repaired at a later period, is perfect,—no grass-grown mounds, but simply fallen or falling buildings, with streets encumbered by the masonry and countless arches; no heathen temples within the city, but five Christian churches, one of them probably a cathedral, and all of the Basilica type. The apse was generally perfect, with the plinth and beading decorated by bosses carved with alternate heads and crosses. Some of them we photographed. Outside where we were camped was the amphitheatre, now grass-grown, and several very deep cisterns, not very large superficially. The most interesting ruin here is a Christian mortuary tower, which Mr. Palmer has sketched, close to the ruins of a Byzantine church, of which we took photographs. This tower is a landmark for miles round, and ludicrous traditions are locally attached to it. Um Rasas appears to me to be probably the “ Thamatha” of the ‘ Notitia,’ RQ 228 REPORT—1872, the station of the first Valentian “ Ala ;” and the name is preserved in the Wady Thamed close by. It certainly must have been one of the most important cities in these highlands in the Roman times, and is on the Roman military road. We made expeditions eastwards to the ruined fort M’seitbeh, where there was abundant water in a large cistern, and the Hadj road eleven miles east of it, east of which is the ruined Khan Zebib, which places have never before been visited. Khan Zebib is evidently built on the ruins and with the débris of a former great city; and to the east of it are the remains of an interesting Doric temple. Jemail (two and a half miles south of Um Rasas) and Ghazal (Khazaleh of Palmer’s map) were also visited. At both of them there was water, and traces of vineyards in the neighbourhood. Khan Zebib is above the rise of the Wady Shabek, the head feeder of the Zerka Main or Callirrhoe, a wide shallow basin fed by the drainage from a lime- stone range to the east of it. The Hadj road is here closely marked by about fifty parallel furrows, formed by the tread of long lines of camels pursuing the same tract for ages in succession. Near the great temple east of Khan Zebib are numerous natural caverns, which form subterranean labyrinths, and have been cemented and used as reservoirs in past ages: now they seem occasionally employed as hiding- places and folds by the Bedouins. Beyond these are a number of artificial mounds and circles of stones, affording unquestionable evidence of the cairns of the primeval inhabitants. We spent several days at Um Rasas, in the hope of securing a stone which’ is buried there, but which the Bedouins would not reveal to us. I have seen a squeeze of this stone, which is now in the possession of Dr. Dodge, of Beirut, having been taken by a Bedouin before the stone was buried; it is of basalt, and bilingual. The centre is occupied by a serpent biting a scorpion. On the serpent are inscribed numerous Pheenician characters, and on one side is a long inscription of many lines in the Phoenician cha- racter; on the other, arranged in a similar semicircular fashion, one in apparently Nabathean letters. I hope ere long to obtain a copy of this important inscription. From Um Rasas we travelled N.W., passing Beihar and the ruins called Draa, a Moabite city of the very oldest type, probably the Zoas of Eusebius, and the seat of a bishopric. This place has not been previously noticed, and solves some of the difficulties which have encumbered the topography of the Zoas of the Pentateuch. In two hours we crossed the Wady Thamed, overhanging which, on a peninsula formed by the river, is an immense heap of stones, apparently an old keep and enclosure. It is 300 feet above the Wady, and is known as Um R’mail. We made this our station for a few days. Three miles north of it is Zafaran, with a fort of large squared stones on the top of a till, and the remains of the town below it. There are no traces of arches here, and the place seems pre-Roman. It may perhaps be the Naar Safari of the ‘Notitia,’ the station of the second Ala miliarensis. Near it are the similar ruins of E] Alaki, and two miles further El Herri, a fortress on a knoll and a town below it, with the old Roman road passing close by. The next ruin, N.E. from hence, is Um Weleed, one of the most important and extensive in the whole country. The ruins are of three distinct types, pre-Roman, Roman, anda Saracenic Khan. No previous traveller has visited it, and its local name gives no clue to its ancient name, The Roman road passed GEOGRAPHICAL EXPLORATION OF MOAB. 229 through it. There isan amphitheatre; the pavement of a forum, surrounded by the bases of columns, is entire, 41 paces by 38, and just beyond it the eastern gate of the city, outside which is an interesting little Doric temple, 12 yards by 10, facing east, the niches being still zn situ. The streets here have been arcaded; and we found in some places the flat slabs of stone which formed the flooring of the dwellings above the streets still entire. By the side of these old streets the ancient Khan looked but a work of yesterday. We followed the Roman road from Um Weleed to Um el Kuscir. There is no ruined bridge as marked in the maps; but there is a long massive wall across part of the plain, built for the purpose of guiding the floods into the cisterns. Um el Kuseir is of the same type as the last named city, but not so extensive. Hence we struck eastward to Ziza, where we spent a weck. It is men- tioned in the ‘ Notitia’ as the headquarters of the Dalmatian Illyrican cavalry. The remains of Ziza are very perfect. The tank is simply magnificent, 140 yards by 110 (see Photograph): many of the stones are 6 feet in length. Much engineering ingenuity is shown in the mode by which the upper valley has been banked, and a system of sluice-gates arranged for filling the pool and letting off the superfluous rainfall. Above it is a strong Saracenic fort, still entire, and which was occupied by Ibrahim Pasha. The upper story has been fitted for engines of war, and . many stones taken from Christian chambers marked with plain symbols appear in the walls. The ancient city is on a long ridge further up, occupying several acres, and full of sculptured ruins. The whole hill is honeycombed with cisterns. The principal remains seem not earlier than the Christian period, comprising several churches. Six miles east of Ziza we crossed the Hadj road, not far from the base of the limestone range which forms the eastern limit of the highlands of Moab. A little beyond this, at the very base of the hills, but without any trace of water, we discovered a palace which surpasses in interest any other of the ruins which this expedition has brought to light. From the eminences near Ziza we had detected a pile of masonry in this direction ; the Beni Sakkr gave it the name of Mashita, and spoke of it as being like the other ruinous heaps which we were continually examining. A gazelle had beguiled our ride, and ‘not a little were we startled when we reined in our horses in front of a fagade of which only the photographs ean give the slightest idea. Two days were well spent in photographing and measuring (see Plan and Photographs). We were in utter perplexity as to the origin of these magnificent buildings; nor was our difficulty lessened by the long lines of inscriptions in an unrecognized character on the lower corners outside the inner palace. One thing was plain, the palace had never been finished, at least in its decorations; and we have to thank Mr. Fergusson for having given us the clue to the solution of the problem. Mr. Fergusson is decidedly of opinion that it is the work of Chosroes II., the Sassanian king of Persia, after his conquest of Syria, North Arabia, and Egypt in a.p. 611- .622. The builders seem to have been interrupted, for it is evident that the decorations were never finished. This is explained by the advance of the Emperor Heraclius, who so brilliantly swept the Persian out of the whole of his conquests, and recalled for a moment the glories of old Rome. There are no more ancient remains of any kind in the neighbourhood, and no Saracenic additions whatever. Mashita stands forth in absolute solitude and isolation, unlike the cities of Moab, with their traces of many - 230 REPORT—1872, epochs. It probably was erected as a hunting-palace, to gratify the luxurious taste of Chosroes. Mr. Fergusson has pointed out the indications in this wonderful sculptured facade of Byzantine art, guided by Persian sei 4 (see Plan and Photograph), It is not a little strange that so perfect and unique a building has remained unnoticed and undiscovered by any European before us, and without any tradition attaching to it by the Bedouin. There is no trace here of any de- struction by the hand of man. The sculpture is of extraordinary depth and scarcely weathered, as may be seen by the photographs. Travelling north from Ziza, the ruins of Kustul, evidently some Roman ** castellum,” possess, as may be seen from the photographs, a character distinct from any other Moabite cities. There are the several walls, cisterns, and arches, these latter unusually massive and well finished; but besides them two castles, with many semicircular bastions, surmounted by a sculptured balustrade of the Corinthian order. The principal castle is 84 yards square. The smaller castle, isolated from the city, would seem to have been a temple fortified. We found a Greek altar of white marble, and several marble capi- tals, which must have been imported from the Greek islands or Asia Minor, Below the city is a tank like that of Ziza. Six miles north of Kustul I visited Thenib, a heap of cisterns, walls, and arches, and two miles further north Rujum Hamam, a ruined heap of shape- less stones. This was our extreme north-eastern point. Travelling west from Kustul, Um Zibarah presents only a large assembly of hummocks and hollowed cisterns. Crossing the commencement of Wady Jifar we reached the top of Jebel Jelul, a most remarkable hill, hitherto unnoticed, or placed close to Heshbon, rising 300 feet above the plain and covered with ruins. Pieces of Doric entablature were strewn about. The panorama from Jelul was uninterrupted for several miles in all directions. From Jelul, turning south, we passed Sufa, crossed Wady Habis, the ruins of Betan el Bareil, Habis city, and then leaving the highlands followed down the gorge of the Habis, the main feeder of the Zerka Main. Owing to the ruggedness of the road it was a two days’ journey to the hot springs of Cal- lirrhoe. We had now left the country of the Beni Sakkr, and were in that of the Hamaydeh. These latter have been spoken of as an independent tribe, and the remains of the ancient Moabites. We never found them inhabiting huts, but only tents like other Bedouins; physically they seemed decidedly inferior to the Beni Sakkr, who treat them as mere vassals, pasturing their cattle and camels where they please in Hamaydeh territory, and summoning them to their service. They obeyed the orders of Zadam implicitly, when he desired Ibn Tarif or any other of their Sheikhs to act as our guides in any part of their country. Ner were we once asked for backshish from the time we left the Kerak men till we reached Jericho. Their chief men never pre- sumed to enter the tent with Zadam, but consorted with the servants. The gorge of the Callirrhoe is one of the grandest I have seen. We had to ascend to a narrow secondary plateau and then descend 1300 feet to the hot baths. The north face of the ravine is red sandstone below and white limestone above; the south face is formed by a stream of basalt, in many places co- lumnar. Our camping-ground was delicious, by the side of a warm sulphur torrent, 96° Fahr. just where it dashes into the cooler stream of sweet water in front of us. The hot sulphurous springs all issue from the north face of the gorge, at the junction of the red sandstone with the limestone. In a reach of three ‘miles there are ten principal springs and many minor ones, dashing down “ GEOGRAPHICAL EXPLORATION OF MOAB. 231 little nullahs or canons, all shaded with date-palms and canebrake. The temperature of the upper spring was only 85°, that of the fifth and tenth, which are the largest, was 135° and 140° at their exit from the rock, The heated stream of the Callirrhoe retains a temperature of 70° at its mouth. There is not a trace of Roman baths or of building of any kind; this is not to be wondered at when we observe the rapid deposit of sulphur now forming about all the lower springs. These sulphurous deposits form crum- bling cliffs, under which the hot stream has in many places made itself a tunnel, to which the Arabs have pierced holes through the overlying crust, over which they sit and enjoy a natural vapour-bath. We made this lovely glen our headquarters for eight days, and thoroughly examined the neighbourhood. The castle of Macherus (M‘Kaur), the place of the martyrdom of St. John Baptist, does not seem to have been noted by any predecessor, and is wrongly placed in the maps. It stands to the 8.E. of the head of the Wady Sgara, the next glen to the south of Callirrhoe. Its natural position is accurately described by Josephus ; but there is nothing left to give any idea of the great strength of its fortifications. The citadel, isolated, as Pliny observes, from the city below, has only foundations of the keep just level with the soil, circular, exactly 100 yards in diameter ; within it is a well of great depth, a large and deep oblong cemented cistern, and two dungeons, one of them very perfect. The town occupied the ridge of a long crest running east and west to the west of the fortress, and is marked by a stupendous heap of stones, beyond which are the foundations of several forts and of a small temple. The stone heap is 250 yards long and of great height, and the crest is 3800 feet above the Dead Sea. The finest view on the east side is, I think, from the top of the ridge between M‘Kaur and Callirrhoe. Attarus, the ancient Ataroth, and Kureiyat (Kiriathaim) were also visited. Attarus is certainly in extent among the most considerable of the Moabite ruins, but featureless ; Jebel Attarus is three miles distant from the site which bears the name of ancient Ataroth. It has been crowned by a massive square fortress, The feature most remarkable in this treeless country is a fine tere- pinth, which attracts the eye from far and is noticed by Burkhardt. Round this hill and in the undulating plain between it and the city the ground is sparsely covered with trees, the only wooded spot in the highlands. Tere- binths, oaks, and especially the almond-tree in abundance, present an aspect most refreshing in this bare and monotonous land. Kureiyat has nothing worthy of note, and from hence to the Arnon there is scarcely a ruin on the eastern edge of the plateau. In the neighbourhood of the Callirrhoe we observed several prehistoric stone circles, like those found at Beitin and elsewhere, and many cairns, which seem far anterior to the mounds of the cities. An expedition to Zara (the Zareth Shaphan of the Bible) was full of interest. The narrow ravine of the Callirrhoe it was impossible to follow ; and we were compelled to mount the heights, cross two more gorges, and follow the crests till we descended 2000 feet from a lower plateau upon the oasis of Zara. This is not, as marked on the maps, at the mouth of the Callirrhoe, but consi- derably to the south. It was a city of Reuben, its frontier town on the shore, and shows few traces of later occupation. We may trace the features of the Jewish town, a central fort on a knoll and the houses clustering round it, as may be seen to-day at Gibeon and elsewhere. We were surprised to find a wide extent of rich land fringing the Dead Sea, abundantly watered by hot springs, some sulphurous and others sweet. This belt reaches to within a short distance of the mouth of the Arnon. Northwards some bold 202" ; _ REPoRT—1872.: headlands intervene between it and the Callirrhoe, and a scramble we had to get round to the fissure through which the river emerges, forming a spit covered with tamarisk at its entrance. It is needless to say that we found the shore-line laid down by Lynch most accurate, but the sketching-in of the country, even close to the water’s edge, most inaccurate, as his party in this district seem rarely to have left their boats. There is a striking contrast between the eastern and western shores; on the latter there are only a few patches of verdure, scarcely breaking the desolate barrenness of the coast-line ; on the east all is exuberant verdure and continually running streaimlets to the water’s edge. The palm-tree is abundant, and clings to the sides of the little ravine from a height of over 1000 feet to the very edge of the sea (see Photograph), while the varying shrubs and flowers overpower the botanist. This must be attributed to the sandstone formation, which, underlying the eocene deposits, nowhere appears on the west, while it is greatly elevated on the eastern side. Arrived at the mouth of the Callirrhoe, we ascended the gorge on foot with an ibex-hunter for our guide, and though the seranshline was severe, were richly rewarded. At the shore the cliffs : are 600 feet high, and the opening only 100 yards across, sometimes, as we ascend, only 30 yards. It winds and turns suddenly, and the glow of the red sandstone walls is gorgeous. Paths or tracts of course there are none ; and we were compelled to climb as best we could up the side, when a waterfall, Jebel Moia, 7. ¢. ‘‘ waterhill,” barred all progress. After having thoroughly investigated this district we turned northwards, visiting at leisure the sites on the western edge of the highlands where the cities of Moab were most crowded. In this region, as far as Heshbon, I must notice the great number of noe mens which everywhere occur in these parts, which are too rocky to have been ever subjected to the plough; I have counted more than twenty in one morning’s ride. They are all of one pattern, three stones placed endwise forming three sides of a square, and a large stone forming the cover, generally about six feet in diameter. I never found four supporting stones. We followed a road, Jewish or Roman, to Maon and then to Medeba. On every side are the foundations that mark the boundary-walls of fields or vine- yards, while the Belka Arabs here, for the first time, exemplify the natural fertility of the country by their cultivation of large tracts in wheat and barley. For the ruins of Main (Boal Meon), which occupy four adjacent hills, and of Medeba, which retains its Bible name unchanged, I can but refer to our -photographs. At the latter we camped for some days and visited the ruins to the east and north. Medeba contains more perfect Roman remains than any of the other western cities of the highlands. It is not in a hollow, but, like all other towns of Moab, on the top of a knoll. The forum, or whatever else it may have been, is the largest we have seen, 280 by 240 yards, with a colon- nade, and the bases of the columns still im situ, many temples and later ebristian churches. The most remarkable remaining work is the reservoir, built on the same principles as Solomon’s pools, and 120 yards square, with its walls 30 feet thick at the base, tapering to 18 feet. It would be tedious to describe the temples and churches of Medeba, which at least prove the dense population of this part. The other northern cities of Moab call for no special mention; they occur every half mile, and are alike in their main features. Man has had little or nothing to do with their decay. We examined carefully the ON THE ELIMINATION OF ARBITRARY FUNCTIONS. 233. heights overhanging the Dead Sea with a view to Nebo. The modern Nebbeh affords exactly the view described in Deuteronomy, and I can find no other to rival it. The city of Nebbeh is lower down on a spur of the range, and with remains more perfect than ordinary. The whole country is here densely erowded with ruins; but the names do not indicate their ancient equivalents —Maslubiyeh, Kuseir, Et Tein, &e. From Nebbeh we worked to Ayun, Mossa, Heshban, &c., which have been visited by many others. We made some sojourn in the Seisaban, and iden- tified Ramah, Beth Jesimoth, and other scriptural sites, and thence worked down the shore of the Dead Sea towards Callirrhoe. We ascertained that the Seisaban, the ancient plains of Shittim, is of very much greater extent than the maps represent. The fertile Ghor extends from the Beit Nemeirah, or upper fords, to within 3 miles of the mouth of the Callirrhoe, and is well watered throughout; but in ancient warfare this region could never be defended, and the ruins are unimportant, though there is not a single mound without the stones which tell of some fort of the olden time. We trust we have by our expedition carried out the intentions of the British Association. We have carefully mapped.the whole country north of the Arnon, every previous map of which we found to be a mere work of the imagination. We have left no ruin in that tract unexplored; and though we ‘have brought home no Moabite stones, we never dreamt we should be able to do so. The grant was for geographical exploration, and that we have endea- voured consciehtidusly td carry out, and have brought to light some twenty ancient cities hitherto unvisited and unknown, and others known only by name. The zeal of my companions enabled me to exhibit about 100 photographs. Sur Vélimination des Fonctions Arbitraires. By Cu. Hermite, Corr. Member of the Mathematical Society, London. [A communication ordered by the General Committee to be printed im extenso.] C’xst la définition géométrique d’une famille de surfaces par un certain mode de génération qui a conduit 4 définir analytiquement une fonction z de wx et y par le systéme de deux équations ¢(2, ¥,2, a, A, B,... eat (2%, 9, 2 a A, By. .L)=0, et eee ov entrent un paramétre variable a ef un nombre quelconque n de fonctions arbitraires de a, représentées par A, B,...L. Obtenir une équation aux différences partielles, 4 laquelle satisfait la fonction z quels que soient a et ‘ces » fonctions, sera la question traitée dans cette note par une méthode nouvelle. J’observe en premier lieu que les relations données permettent de considérer x et y comme dcs fonctions de z, dont les dérivées successives, ae n OR nm Oe =—, v ae Te v= ST dz dz dz dy pete yt OY ! (fe 4 = = —--, see Ida’ dz dz’ 234 REPORT—1872, s’obtiendront, soit directement si l’on peut avoir x et y explicitement exprimés en 2, soit par les régles relatives aux fonctions implicites. Dans ce dernier cas nous aurons @abord, Start By 1p Los Mg etlagn sy tag Doe Mama da lz de dy” dz : puis: e n din, ny (lo Co Fo d¢ &o 1 €$_9 4 rad ee dy” (ae dady’ dy? av) ei dydz ar 7 oS dyn ,dbn, (Pp Cy @p Gy ., ay _ vais die ae pi i? dey pe a vt) +z, — "Vagaet ae dz (3) et ainsi de suite. En second lieu je remarque que z=f(w, y) étant la fonction qui résulte de Vélimination du paramétre a, on reproduira identiquement la quantité z si l’on y remplace « et y par les valeurs qu’on tire de la résolution des équations (1), car autrement ce serait de deux relations conclure une troisiéme qui en serait distincte. D’aprés cela et en regardant a et y comme fonctions de 2, la premicre dérivée de lidentité obtenue donnera Végalité suivante : la seconde et la troisiéme celles-ci: dz dz Wz dz dz ——— si —- n! — pes A — a of ay! = 0, . ry . . 5 da Pk ah Ge see fin. i a . dz dz Pz ra “ of" + apt 38 a 3 a" a) wm ae) ' Seeker " ‘3 Es ay ay i da aT y Pa dz dz dz~ , + eS dx*dy” dady” aye & >) = a 0 les quantités a’, vw, w'", y', y", y"” devant étre remplacées par leurs valeurs en fonction de z, ou éliminées au moyen des relations (2), (3), &e. En con- tinuant les mémes calculs jusqu’a la dérivée @ordre n, on parviendra & un systeme de n équations, ot les dérivées particlles de Vordre le plus éleyé seront éyidemment : (8) dz d*z dz da” da dy’ *” * dy et, en y joignant les deux relations proposées, il sera possible d’effectuer ’élimination du paramétre a et des n fonctions arbitraires A, B,... L. C’est le résultat cherché qui est ainsi une équation auw différences partielles Vordre nu. Dans le cas le plus simple de n=1, lorsquw’il n’existe qu’une seule fonction arbitraire, cette équation aux différences partielles s’obtient immédiatement en résolyant par rapport 4 a et A les équations 9(2, ¥,2%,a,A)=0, (a, y,z,a,A)=0; ayant en effet G=0(v,y,z), A=¥(x, y, 2); ON THE ELIMINATION OF ARBITRARY FUNCTIONS, 235 il ne restera plus trace du paramétre ni de la fonction arbitraire dans les re- lations (2) qui deviennent : dd, ae, be = 0; OM ee yf +. a¥ 9, dx dy dz dx Z et le résultat de ’élimination de x’ et y' entre ces équations et P’équation (4) est immédiatement donné en égalant 4 zéro le déterminant: dz de dv \ da’ dx’ dx’ dz db dv iy ay ay? do dw dz’ -dz = oat Sans m’arréter & tirer de 14 les équations aux différences partielles des cylin- dres, des cones etc., je prends pour exemple les surfaces réglées dont la géné- ratrice est la droite : ew=Az+B, y=az+0, ce qui nous donnera un cas d’élimination de trois fonctions arbitraires. Or ayant z'=A, z"=0, a’’=0; y' =a, of 80; ght sas les équations (5) et (6) deviennent simplement Gz de We EE Sasa he tb), Ge dady ap ; “) dz dz Gz de — meat ’ , —{A, =0, (a da*dy dady” de a), A Bee A iene | et il ne reste plus qu’a effectuer l’élimination de —, ce qui est bicn en effet ; « le résultat connu. La considération des surfaces enveloppes, ot s’offre un mode de génération enticrement différent des précédents, conduit 4 définir une fonction z de a et y par deux équations contenant un paramétre variable a, et dont l’une est la dérivée de l'autre par rapport 4 ce paramétre. En désignant de nouveau par A, B,...L, ~ fonctions arbitraires de a, ces conditions s’expriment ainsi ; Fe Y 2, a, A, B, eee L)=0, -_ © @ © © «© (7) ds Tad (% tp % a, A,B... L)=0, > pi oh 5, wt ee et nous nous proposons encore de former entre la fonction et les variables indépendantes, une équation aux différences partielles qui subsiste quelles que soient ces fonctions de a. A cet effet je concois que x et y soient déterminés par les équations (7) et (8) en fonction de z, de maniére 4 avoir toujours les relations préeédemment obtenues : dz dz Gz tie. 0.2, dz dz. Ke, ' ney —1=0 te at Oe goth FT ie ene ieee one eS 1 BN oss oa dy” oy da AN dy” ‘\dx®” dady’ apt), eh 236 REPORT—1872., Mais je procéderai différemment pour calculer les dérivées: en mettant a profit une circonstance importante qui s’offre lorsqu’on veut dz dz tiver de ces équations les dérivées particlles aa a Différentiant pour cela la premicre par rapport 4 a, en supposant a foinibien de a, y, 2, il vient q df , df dz , df da _ dx dz dx dadx ”’ ou simplement d’aprés l’équation (8), Uf ade 4, da‘ dzedx” et on obtiendrait de méme: of, df de _ dy dz dy Or nous n’ayons plus dans ces relations les dérivées des fonctions arbitraires par rapport au parametre, et nous en tirerons les quantités cherchés a, 7’, ar dz +... exprimees au moyen seulement de A, B,... L, en observant que a. ri par oy étant une fonction enti¢rement déterminée de a et y, que jappellerai pour un moment 0 (x, 7), on aura d0 dé a! dé ie a ~ > dz da dy dot Von voit qu’on devra écrire d. fdz\ « @a, Wz dz a) ~ dev a dady ys et pareillement dz vit Wz ' ‘: dy aa — seh _ D‘aprés cela en représentant suivant l’usage, les dérivées partielles du pre- mier ordre par p et q; celles du second ordre par 7, s, ¢, nous aurons pour déterminer a’ et y', ces deux équations : Tat get ee tat at Geet Zew'tw) =0, dx" dady dudz dadz” d yd? OF a: oto? tS yy! d°f a Hog a? i fap 44 af af ; 0, dady eT ay? y Y ade ydz + Fe jae 72) ets = (Se +ty')= et il est clair qu’en continuant de différentier par rapport 4 z, on formera de proche en proche, les dérivées de x et y jusqu’a un ordre quelconque n—1, avec cette circonstance que les dériyées partielles de z Jusqu’ a ordre n seront introduites dans leurs expressions. Il en résulte qu’en les substituant dans les relations (4), (5), (6), ete., on sera conduit 4 un systeme de 1 équations ON THE ELIMINATION OF ARBITRARY FUNCTIONS. 237 entre ces dérivées partielles et les quantités a, A, B,...L, Nous pouvons done en y joignant celles-ci, Fay, 2, dy Ay By «oh L)=0, of ip Yf »=0, i + a 0 de — dz des? effectuer l’élimination du paramétre et des n fonctions arbitraires; c’est le résultat cherché qui est ainsi une équation aux différences partielles d’ordre x. Nous allons en faire l’application 4 deux exemples tirés de la géomé¢trie, aprés avoir remarqué que les équations ci-dessus, en x’ et y', jointes 4 la relation (4), pe' +qy'—1=0, donnent par l’élimination de w' ety’, la condition A=0, A étant le déterminant du systéme suivant: Beye diy pdf yl edits aap api da? daxdz dz dady . daxdz dz df af df af Cha i df ’ — S, == ; t | q dady dydz” dz ‘ dy’ dydz q+ dz ef vf af df ey et EP ! wl phe ” drdz ig dz*? dydz Ti dz? Mais si on ajoute aux termes de la premicre et de la seconde colonne hori- zontale ceux de la troisiéme, multipliés d’abord par p et ensuite par q, on aura plus simplement A= B’—cl en posant: Cf Of y df 1 = eal poe Wet ye +P” ‘ 2 dadz dX ; p) + dz” SET os, Ak ath ye df O=(F> ae gba) + Zs if af 8 if dady dydz dxdz a df q+ dz? PYt+ a s. Ce résultat peut s’obtenir directement d’une manicre trés-facile ; je me borne- rai 4 en faire l’application d’abord aux surfaces développables enveloppe des positions d’un plan mobile: z+av+Ay+B=0, ce qui donne immédiatement A=r, B=s, C=é d’ou par conséquent l’équation si connue: s?—7rt=0. Soit en second lieu les surfaces canaux, enveloppe des positions d’une sphére de rayon constant, (e—A)’ + (y—BYy + (¢—a) = @, dont le centre décrit une courbe quelconque. On obtient alor’ JA=1+p't(c—a)r, JB=py+(c—a)s, JCH14¢°+(c—a)t, cet le paramétre s’élimine au moyen des relations x—A+(z—a)p=0, y—B+(z—a)q=0, qui donnent en substituant dans l’équation de la sphére, a es V1+p*+¢@ De la résulte l’équation aux différences partielles du second ordre : a(s'—rt) a [d+¢r— 2Qpqs + (1+p*)¢] V1l+p+¢+ (1+p?+¢ y=. nw 238 - REPORT—1872, Nous ne nous sommes occupés jusquwici de la formation des équations anx différences partielles que dans le cas d’une fonction de deux variables. Considérons maintenant par exemple une fonction w de 2, y, 2, en la définissant par ces trois équations, ol entrent detx paramétres a, 2, et un nombre quelconque de fonctions arbitraires A, B....L, de ces para- metres, savoir: — (2X, YZ, U, a, B, A, B,...L)=0, W(@, y, 2, u, a, 2, A, B,...L)y=0, 6 (a, y, z, u, a, B, A, B,...L)=0. L’élimination des fonctions arbitraires s’effectuera par la méme méthode que précédemment, et donnera pour résultat une équation aux différences parti- elles dordre n, La méme conclusion s’obtiendra aussi en considérant les relations : : df df F(x, y,2, u, a, B, A; B,...L)=0, qa =0, agers Mais elle n’a plus lieu, si l’on pose seulement deux équations ayec un seul paramc¢tre variable, savoir : o(a,y,2,u,a,A,B,...L)=0, Ya, y,2,u,a,A, B,... L)=0; ear alors on peut former une équation aux différences partielles d’ordre n, représentant le résultat de I’élimination d’un nombre de fonctions arbitraires de a supérieur 4 n, et égal a ——. Lorsque le nombre des quantités A, B,...L n’est point compris dans cette formule, s’il est égal a 4 par ex- emple, de sorte qu’on ne puisse pas obtenir une équation aux dérivées par- tielles du second ordre, on parviendra en introduisant les dérivées du troisiéme ordre, 4 plusieurs relations distinctes au lieu d’une seule. Cette circonstance que présente souvent l’élimination des fonctions arbitraires, montre qu’on doit attacher une grande importance aux formes analytiques ou l’élimination donne-lieu 4 une conclusion précise, & une seule et unique équation aux différences partielles; et tel a été le motif qui m’a fait entreprendre ces recherches dont je prie l’Association Britannique de vouloir bien agréer Yhommage. Report on the Discovery of Fossils in certain remote parts of the North-western Highlands. By Witu1aM Jouyy. A .imestone runs from Durness and Loch Eribol, in the north of Sutherland, with varying thickness but more or less continuity south by Loch More, Inchna- damph, Ullapool, and Loch Maree, to Kishorn near Loch Carron, where it dies out on the mainland. This limestone rests on a thick deposit of quartzite, and this again on the red sandstone of the west coast. All of these rocks enter into some of the grandest scenery of the North-western Highlands. These rocks were considered unfossiliferous till 1855, when Mr. Peach made his great discovery of those fossils in the Durtiess limestone which were classed by Mr. Salter as Silurian, and the discovery of which enabled Sir R, Murchison to complete his classification of the rocks of the N.W. of Scot= ON FOSSILS FROM THE NORTH-WESTERN HIGHLANDS. 239 land. These fossils were discovered in the limestone of Durness, where they are numerous, and where more have since then been found. ‘This Durness limestone forms, geographically, an isolated basin lying to the west of the great strike of limestone which runs from Eribol to Skye. In this detached deposit only have fossils been found, with the rarest exceptions, to be named below. It is important, therefore, that organic remains should be found, if such exist, in the great line of strike, in order to determine whether this last limestone is fossiliferous or not, and also whether the Durness lime was deposited under the same or under different conditions. It was for the purpose of making diligent search along this great line of deposit, that a grant was asked and obtained last year from the Association; as also for the discovery of more perfect specimens, and, if possible, new species, from the Durness lime, in order to determine more precisely the relations these fossils bear to the Silurian and other systems, than could be made from the speci mens submitted to Mr. Salter in 1858. Since the Edinburgh Meeting last year, search has been instituted along this great strike of limestone at Durness, Loch Eribol, Inchnadamph, Elphin, and Kinlochewe, and will be made at Ullapool and Loch Kishorn. At these points, certain clergymen, teachers, and other gentlemen have kindly consented to do what they can towards the discovery of fossils, so that more systematic search will now be made than heretofore. Good results may be anticipated, if not in the discovery of fossils, at least in greater certainty as to the presence or absence of organic remains in these remarkable rocks. At Durnsss, in July of last year, many fine fossils were obtained, through the efforts of some members of the Committee and their friends, from a re- markable island of limestone near Cape Wrath, called Ellan Garye. These fossils were shown at the Meeting in Edinburgh, and were pronounced by Mr. Peach much finer than any he had seen from the same locality. They have been secured as the nucleus of a collection for the Association. A col- lection of fine specimens was also made by a student resident in the district, for Professor Nicol, of Aberdeen, who now has them in his possession. This island is so difficult of access, except in the very calmest weather, that we were unable to land both this year and last. In June of this year, along with some friends, I landed on a rocky headland of limestone, on the west side of the Kyle of Durness, where fossils are exposed on the weathered surfaces of the limestone in remarkable numbers, and I obtained some good speci- mens. Several gentlemen in the neighbourhood have kindly agreed to make diligent search in the Durness limestone at various points, and one of them has also kindly allowed the use of his boat for this purpose; so that good work will be done at the least possible expense. Loca Ertsor.—No fossils have yet been discovered in the extensive lime- stone rocks on Loch Eribol. An Orthoceratite was presented to the Jermyn- Street Museum by Sir R. Murchison, which he got from Mr. Clark, of Eribol House. This Orthoceratite is unique, as being the only organism found in the quartzite. It was not, however, found in situ, nor at the spot marked by Sir Roderick in his paper in the ‘Geological Journal’ of August 1860, yol. xvi., but was picked up in a detached piece of rock between Eribol House and the loch to the west. Lime-works have been established on Loch Eribol on the limestone peninsula of Heilim, and quarrying has been done in connexion with these, but as yet no fossils have been found. These ope- rations afford an unwonted opportunity for their discovery, and the strictest watch is to. be kept by the lessee. Incunapampu,—In the immense development of limestone at the head of 240 - -REPporT—1872, Loch Assynt no fossil has yet been discovered, except two by Mr. Peach in the stinking limestone above the manse near Inchnadamph. One of these was an Orthoceratite. I spent some time on this limestone this year, but was unsuccessful, except in finding a piece that may turn out to be organic. Mr. Peach’s discovery shows that fossils may be found here; and the parish teacher is to make search during next year. Epuin is situated.not far from the splendid limestone-cliff of Craig-an- Knockan, figured by both Murchison and Nicol in their papers on these rocks. Here the limestone is largely developed, and has been quarried at various points. The teacher of the Society school is to look for fossils. Near Uttapoor, on Loch Broom, there has been a good deal of quarrying for lime-burning, and the sections are extensive. Something may be dis- covered there. Search will be made. At Kintocuewe, at the head of Loch Maree, there is not so much lime- stone exposed as in other parts. The Free Church teacher there is to devote his spare time to a search; but much cannot be looked for, as the limestone is in contact with igneous rocks, in Glen Logan, where it is found. At Locn Kisyorn there is a large exposure of limestone along the loch near Courthill. This will be submitted to careful search. In this way the whole line of strike of this limestone from N. to 8. will be examined by intelligent men, who have kindly and earnestly entered into the work, and we consider ourselves fortunate in having secured such cooperation, The Committee confidently hope that by next Meeting they will be en- abled to present to the Association a good collection of organic remains from these interesting rocks; or, at least, to have done something that will contri- bute to greater certainty as to whether, and to what extent, these rocks are fossiliferous or not. Report of the Committee on Earthquakes in Scotland. The Committee consists of Dr. Brycr, F.G.S., Sir W. Tuomson, F.R.S., D. M1tne- Hog, #.R.S.#., and J. Broven. As Convener of the Committee‘on Earthquakes in Scotland, I have to report that the last year has passed without any incident coming within the scope of this inquiry ; there has not occurred any sensible disturbance in the Comrie district, or oscillation of the lakes in the neighbourhood, such as those recorded in former Reports. In other parts of Scotland the same freedom from earthquake-movements has prevailed. But this state of quiescence is not likely to continue; and the attention of the Committee has been turned to the remedying of those defects which from time to time are apt to occur with instruments long in use, and to the extension of the means of observing to other localities suitably placed for the pur- pose. The accomplishment of this object renders necessary some more simple means of noting shocks than any which have hitherto been applied by the Committee. The seismometer belonging to the Association, which now occupies the tower of the parish church of Comrie, is of too complex con- struction, and takes up too much room, to be applicable except in a few peculiar localities. Some simple and cheap method of indicating earthquake- movements is thus much to be desired. Any apparatus for the purpose ON THE STRUCTURE OF CARBONIFEROUS-LIMESTONE CORALS. 24] should occupy small space, be little liable to derangement, capable of being put up in any ordinary apartment not of special construction, and its indica- tions such as any intelligent person could easily interpret and readily note. The Committee are now anxiously considering what instrumental means will best combine these several requisites and advantages, and what stations would be most suitable to select in extending the area of the inquiry. Mean- while the seismometer of the Association, which is the invention of the late Principal Forbes, is kept in proper working order at Comrie, where also the first supplemental indicator will beset up. Principal Forbes’s son, Mr. Geo. Forbes, Edinburgh, who has gained some practical acquaintance with earthquake in- struments at Naples, has been taken into their counsels by the Committee, and they have now to request that Mr. Forbes be added to their number. (Signed) James Brycr, M.A., LL.D., Convener. P.S.—During the Session of the Association at Brighton an earthquake of considerable severity occurred in the Comrie district, of which an account will be given next year.—J. B. Fourth Report of the Committee appointed to investigate the Structure of Carboniferous-Limestone Corals. The Committee consists of Jamzus Tuomson, F.G.S., and Professor Harkness, F.R.S. Ar the Liverpool Meeting of the British Association the Committee reported that they hoped, by means of a new process, to produce representations of the most delicate internal structures of corals of the Carboniferous series. The necessity of such a process forced itself on the Committee by the cireum- stance that none of the existing methods of representing corals reproduced faithfully the details of their internal structure. The photographs of the Carboniferous corals exhibited at the Liverpool Meeting represented these details in some of their most delicate forms, This result had been obtained by the transmission of light through their sections ; and subsequent investigations have led us to infer that there are no better means than that of photography for reproducing generic details, Great expense, however, attends this process; and as it is also a very slow one, experiments have been made in order that the same satisfactory result might be more readily and less expensively obtained. At the Edinburgh Meeting they were unable to lay before Section C the same number of results as at the previous Meeting; but they had so far succeeded as to be able to produce two plates, although they were not so perfect as was desirable: they were, however, sufficiently successful to justify the Committee in asserting that a more simple and less expensive process was available. In the application of this process the Committee have been ably assisted by Mr. Reckie, the artist employed by them in engraving the copper-plates. During the past year the investigations of the Committee have been con- tinued with increasing interest. They have now made sections of upwards of 1300 specimens, and have been able to add considerably to this branch of Palzontology. In their Report presented to the Liverpool Meeting ninety-two forms were alluded to ; and these presented characters sufficiently distinct to justify the 1872. 3 s 242 REPORT—1872. Committee in adding them to those previously described by MM. Milne-Edwards and Jules Haime. By this addition, the number of British Carboniferous corals amounts to 156 species. From the forms which have been recently sliced, and also from those of former years, the Committee have ascertained that among these species from 300 to 400 varieties occur, an increase which is so great, and the variations so minute, that it becomes difficult to determine specific characters among these corals. The gradations of the varieties are in some cases so constant, and pass so imperceptibly into each other, that they induce the inference that there has been an inherent tendency in the polyp to vary independent of, but to be modified by, the conditions of its surroundings. The forms occurring in deposits which have resulted from deep water are not only more symmetrical in outline, but also more perfect in their internal structure than such as are met with in strata formed in shallow water, where they have been exposed to the constant shiftings and abrading influence of shore deposits. In the case of such forms as eccur in a matrix originally in the state of fine mud, these are small in size; and they seem to have been gradually exterminated by the impurity of the water, arising from the increase of the fine sedimentary matter originally held in suspension. Many of the specimens which have been sliced are found to be perfectly useless from their imperfect state of fossilization. Some reveal structural characters not previously noticed by authors in this branch of Paleontology ; it is desirable that these should be studied further before a complete classi- fication of this group of animal life is attempted. The classification of corals has in some instances been based upon external aspects ; in others on the number and form of the septa. The number and arrangement of the lamelle which pass from the inner margin of the primary septa and fill up the columellarian space have also been adopted as bases of classification. Some writers regard the form and position of the dissepiments of the endotheca as of specific importance; and some rest generic and specific distinctions upon the presence or absence of the columellarian line which passes from the inferior to the superior, and terminates in the centre of the calice. Observations, however, justify us in inferring that, although these several characters are of importance, they cannot be depended upon for specific determinations. During the last fifteen years no less than 10,000 specimens have been sliced, many of which show structural differences’ in character from such as have been accepted as of specific importance, which induce us to conclude that further examinations are necessary before determining even a variety. It has been stated that the columellarian line has been accepted as of generic value. In a new group of corals, which will form the subject of an extensive memoir, this line is developed, in some instances, near the inferior, and in others it occurs only in the superior portion of the coral. The dissepiments filling up the interseptal space are in some forms angular, in others subangular and. rectangular. We have, however, recognized these several outlines in the safge form, and cannot, therefore, accept the outline of the dissepiments as of specific importance. In the case of the number of lamelle also, some forms present the lamelle in one part, while in another part of the same coral the space is filled up by tubule. ON CLAIMS FOR REWARD FOR ADOPTED INVENTIONS ETC. 243 Concerning the number of the septa, this can hardly be regarded as of value, since this number is dependent on age and surrounding conditions during the growth of the polyp. In order that some definite rule may be obtained as a guide in the classi- fication of corals, it is proposed to select generic types, and, after making sections of these through different parts, to exhibit their structure in plates, from the ova to their mature forms; and it is only when this is faithfully done that we can hope to determine where a species begins and a variety ends. We have, in conclusion, to thank the British Association and many kind friends for the assistance rendered us, and hope for its continuance until this laborious but interesting investigation be completed, as we are satisfied that results will be obtained commensurate with the time and expense which the work has cost during the last fifteen years. A sum considerably in excess of the grant having been expended, the Committee have to ask that a further grant of £25 be placed at their disposal for continuing the investigation. Report of the Committee, consisting of J. ¥. Baruman, C.E., F.R.S., P. Le Neve Foster, V.A., C. W. Merririetp, F.R.S., E. Easton, F.G.S., F. J. Bramwe tt, C.E., W. Hors, V.C., and H. Baverman, F.G.S., appointed to consider the mode in which new Inventions and Claims for Reward in respect of adopted Inventions are examined and dealt with by the different Departments of Government, and to report on the best means of removing any real causes of dissatisfac- tion, as well as of silencing unfounded complaints. Havine regard to the evidence taken by the Committee of the House of Commons on the subject of the Patent Laws, in 1871 and 1872, on the rela- tions between inventors and the Government, as well as to complaints made in Parliament and elsewhere, your Committee were of opinion that they had before them sufficient information “ as to the mode in which new inventions, and claims for reward in respect of adopted inventions, are examined and dealt with by the different departments of Government.” They therefore did not think it necessary or desirable to examine witnesses on the subject. The Committee considered it fully established that the present methodical mode of dealing with inventions submitted to the different departments of Government was uncertain and unsatisfactory in itself, frequently unjust to inventors, and generally detrimental to the public administration. They considered it established to their satisfaction, that real injustice was frequently done to inventors, not only by neglect and procrastination in dealing with their claims, but also by the undue preference of other con- flicting claims urged by officers of the different departments. Without enter- ing into the merits of any cases in point, it appeared beyond doubt that the practical judges of the inventions have been very often rival inventors within the departments. The Committee considered it obvious that this placed both the inventor and departmental officers in a false position, and that the con- sequent decisions could be satisfactory to nobody. As matter of evidence, they considered that these departmental decisions had failed to give satisfac- tion either to inventors or to the public. 82 24.4. REPORT—1872. It remained for the Committee to consider and report on the best means of removing ‘‘ any real causes of dissatisfaction, as well as of silencing un- founded complaints.” The Committee are of opinion that the primary means of effeeting this object isto bring the adjudication of these claims within a jurisdiction inde- pendent of the administration of departments of the public service. As long. as the Patent Law remains as at present, the Committee are of opinion that the only satisfactory method of determining what compensation should be given to inventors, in cases where the Government makes use of their inven- tions, is to have recourse to arbitration. Any inventor whose patented in- vention is used, or beheved to be used, by any Government official, or agent under Government authority, should be at liberty to apply to the proper Government department, stating what is the invention used, and how and where, and requesting that the application be referred to the decision of two arbitrators, who shall be appointed, one by the applicant and one by the Government department, with power to appoint an umpire, and that the proceedings be assimilated to ordinary compensation cases. The Committee, hoping that the recommendations of the House of Commons Committee will, at an early period, be made the subject of legislation, recommend that steps be taken, by petition to Her Majesty or otherwise, to make the grant of Royal Letters Patent for inventions of effect as regards the servants and officers of the Crown in the same way, and to the same extent, as Letters Patent are of effect as regards all others of Her Majesty’s subjects. Your Committee feel that, if in every case officials appointed to investigate new inventions were required to affix their signatures to their reports, very beneficial results would follow, as the personal responsibility thus attaching to them would ensure their full attention, and deter them from rejecting hastily, or on insufficient grounds, any proposition or invention brought before them. The Committee consider that their Report would be incomplete if they did not call attention to an Act for preserving secrecy in the case of inventions connected with warfare. This Act is the 22nd Vic., cap.13. Its principal provisions are :— Section 1. Improvements in instruments or munitions of war may be assigned by inventors to Secretary of State for War. Section 2. Foregoing enactment may extend to assignments already made. Section 3. Seeretary of State for War may certify to Commissioners of Patents that the invention should be kept secret. Section 4. Where he so certifies, petition for letters patent to be left with Clerk of Patents, under seal of Secretary of State. Section 5. Such packet to be kept sealed. Section 6. To be delivered on demand to Secretary of State or Lord Chancellor. Section 7. At expiration of patent to be delivered to Secretary of State. Section 8. Where Secretary of State certifies after filing of petition, docu- ments already filed to be put into sealed packet. Section 9. Copy not to be sent to Scotland or Ireland, nor published, but otherwise provisions of Patent Acts to apply. Section 10. No seve facias to be brought. Section 11. Secretary of State may waive benefit of Act. Section 12. Communication of invention to Secretary of State not to pre- judice letters patent. OBSERVATIONS OF LUNAR OBJECTS. 245 Report of the Committee for discussing Observations of Lunar Objects suspected of Change. The Committee consists of the Rev. T. W. Wess, the Rev. Roperr Haruey, F.R.S., and Epwarp CrossLEY, Secretary. J Tan Committee have pleasure in presenting their Second Report on the above subject. It will be remembered that the Report of last year was confined principally to the discussion of the possible variations of visibility of the numerous spots and craterlets upon the floor of Plato under the same condi- tions of illumination. ‘That now presented is directed chiefly to the discus- sion of the various streaks and bright patches which interlace the spots and craterlets. One interesting and important change has been fairly shown—the floor of Plato becomes darker with the increase of the sun’s altitude. Mr. Birt has suggested an explanation of this phenomenon. Whatever be the true cause of this change, it is very difficult to account for it by the ordinary laws of reflection. When we consider the varying aspect of the streaks at the same time of the luni-solar day, we cannot but think that, with careful observations made with powerful instruments, such as the Newall Refractor and many others, we may be able to confirm or otherwise a physical explanation of these curious changes involving the existence of certain gases and vapours upon the surface of the moon. The Committee can only look upon the study of Lunar Physics as in its infancy, and they trust that in future years the Association will not overlook this important branch of astronomical inquiry. Report on the Discussion of Observations of Streaks on the Surface of the Lunar Crater Plato. By W. R. Birr. In completing the task assigned to me of discussing the observations of the streaks on the floor of Plato, I have been desirous of including every, even the most minute, circumstance bearing on the exhibition of phenomena that may possibly illustrate the condition of a small portion of the moon’s surface at the epoch 1869 April to 1871 April. Drawing my conclusions from the experience of twelve years, I feel that I may confidently say it will be some years before another series of observations of a particular region will be undertaken with the view of so closely examining the spots and streaks cha- racterizing it, unless a staff of efficient observers be organized with the pro- vision of a fund sufficiently ample to defray all the necessary expenses. The work is a difficult one. The staff should consist of not less than six devoted observers, who would, independently and most probably, as in the present case, work with instruments of varying aperture and carefully record all their observations. The principal qualification is a keen eye for the apprecia- tion of delicate variations of tint, and the detection of minute spots of light with a readiness of referring them by estimation and alignment to the respec- tive localities of the region on which they are seen. The observations should not be allowed to accumulate, but should be forwarded at once to an experi- enced selenographer charged with the work of arranging and discussing them. Taking into consideration the results of the discussion of the present and previous years embodied in the two Reports, it appears that in order to con- firm these results, and to open up new investigations in other regions of the moon’s surface, the requisite time cannot well be fixed at less than three years—five would most probably afford the best results. 246 REPORT—1872. The results of the present work may be briefly characterized as confirming, by a direct reference to the sun’s altitude above the horizon of Plato, the sup- position that variations of tint in some measure depend on increasing and decreasing altitudes. The ascending and descending branches of the curve obtained from independent estimations of tint by the several observers are sufficiently near those of the sun’s altitude to enable me to delineate a nor-, mal curve representative of the sun’s influence in darkening the floor of Plato, or else in overspreading it with something of the nature of a dark covering, as his rays strike the surface at the increased angle of about 40 degrees. While this darkening influence comes out most unmistakably, there are variations in the lighter and darker portions of the floor which seem quite irreconcile- able with solar influence of a gradual character. The treatment of the obser- vations under intervals of the luni-solar day fails to bring out any regularity in these variations, and it is only by treating the observations chronologically that the true sequence of the changes can be detected. To do this for every separate streak would not only swell this Report to an unseemly length, but would consume more time than can be devoted to the inquiry. I have, nevertheless, considered separately the changes which were observed in August 1869; and in order to assist in showing more distinctly these changes and their connexion inter se, I have introduced the hypothesis of a dark obscuring medium. Not that I lay any stress upon a mere hypothesis of this kind; it serves to connect the observations, and that is all; it may or it may not be true, and should therefore be held very lightly. In addition to this examination of the distribution of the light and dark spaces on the floor, I have traced from day to day the appearances of a single streak, that desig- nated a, from its first detection in September 1869 to the close of the obser- vations; and to show more conclusively that the variations manifested by this and neighbouring streaks were not dependent upon the same solar influences which contributed to the darkening of the floor, I have arranged all the ob- servations bearing upon them in the order of intervals of the luni-solar day. The principal divisions of the present Report are:—1, the influence of the sun on the floor of Plato; 2, an examination of changes recorded in August 1869; 3, the history of streak a; and 4, observers’ notes arranged in intervals of the luni-solar day, and embodying generally the results of the two years’ observations, It may contribute to a better understanding of the nature of the streaks, their connexion with the spots, and their variability, if the physical charac- teristics of Plato be described. We have :—First, a mountain-cinctured plain, of about sixty miles in diameter, the wall rising to the average height of nearly 4000 English feet. This wall is surmounted at four points by needle- like pinnacles of rock, which rise to a further elevation of 3000 feet, so that their summits attain the height of about 7000 feet above the plain, which is not strictly level, the border having suffered from dislocation, which has raised the floor in a direction from S.E. to N.W. Second, two systems of streaks, as seen between April 1869 and April1871. They are related to the “fault” produced by dislocation. The S.W. system consists of the “ trident,” the N.E. of the streaks G, n, and y (see fig.1). These two systems, which are opposite in direction, are intimately connected with certain spots in their respective neighbourhoods, the 8.W. radiating from spot No.1. Of the N.E. system, streak @ emanates from spot No. 3, » from spot No. 4, and y from spot No. 6. The most prominent streak on the floor is the sector which takes its rise from spot No. 4, but has occasionally been seen in the opposite diree- tion, extending as far as spot No. 3. The S.E. portion, that extending to the “lh he pe ee) OBSERVATIONS OF LUNAR OBJECTS. 247 S.E. border from spot No. 4, has, under very fayourable circumstances, been seen by two independent observers at two different epochs as separate streaks radiating from spot No. 4 (see fig. 15, p. 285). Third, the N.W. portion of Plato, containing spots Nos. 13, 19, 16, 33, and 35, and characterized during the period of the observations by greater alternations of brightness and changes in the forms of the streaks than obtained on any other part of the floor. 3 o g fo} ; o i. s om : 8 5 os 8 5 =] nD a" oS i=] et) ae to] mn =f 2 2 “Sy Sere i 7a reer) iid = By 3 ‘ Vile a 2 4 ! Tae | ity, tl it y (eet te Wn TIMUR EL 12) * wy Ny eat HT I* ; dy | wil \| Ii \| i th | Ty : ulti Wily ty | aT \ Me ful titi : 8 hy Rs \ On| iti : i ni : S Taam OT Aitiel! 2G = Saget A ig “ a ; 2 aD e & cd £8 s £ s “A fe at b ht eee 3 Be] is) Rn Enumeration of Streaks. South-west area. System S.W. of the fault crossing Plato. a. The trident, very rarely seen complete (see figs. 5, p. 252, 6 and 7, p. 254) g. The S.E. arm of trident, its apparent origin spot Na. 1. Cheer cere eeeerereens ee... White spots....... Recent streaks ............0+ 248 REPORT—1872. e. The central arm of trident, apparent origin spot No. 1. e. The N.W. arm of trident, apparent origin spot No. 1. 6. The narrow streak forming the 8.E. bifurcation in the neighbourhood of the N.W. arm of the trident. 6. The N.W. bifurcation in the same locality, a narrow streak. South area. §.W. of the fault crossing Plato. p. A streak parallel with the south border. It was first seen by Mr. Pratt on May 13, 1870. See Report British Association, 1871, pp. 88-91; also History of Streak a, concluding paragraph, post, p. 267. South-east area. N.E. of the fault crossing Plato. b. The sector originating at spot No. 4, of a furrowed character, as seen under the most favourable circumstances. 1. A branch from the east side of the sector, running towards the south- east. North-east area. System N.E. of the fault crossing Plato. B. The streak emanating from spot No. 3. n- The streak emanating from spot No. 4. y- The streak emanating from spot No. 6. d. The stem of the trident, its apparent origin spot No. 1. It is but rarely seen. s. A curved streak seen by Mr. Pratt on August 28, 1869, North area. NE. of the fault crossing Plato. x. A slightly curved streak east of spot No. 16; its northern portion is coincident with a. a. The straight streak east of Webb’s Elbow. q- A branch from « crossing the locality of n, seen only by Mr. Pratt, August 28, 1869. North-west area. §.W. of the streak crossing Plato. - A straight streak nearly aligning with 3 (see fig. 16, p. 286). #. A shorter streak parallel with ) (see fig. 16, p- 286). A curved streak directed towards the N.W. arm of trident. . The continuation of a, west of Webb’s Elbow. Webb’s Elbow (see fig. 1, p. 247). A short streak parallel with Webb’s Elbow, seen once only (see fig. 16, 86). ost > ONS sit Streaks but rarely seen. f. A short streak on the west part of the floor, seen by Elger in 1866. g. A long streak on the west part of the floor, seen by Birt in 1863. h, A short streak on the N.W. part of the floor, seen by Elger in 1866. The north-eastern part would seem to be a continuation of fF: n. A streak crossing the floor from N.N.E. to S.S.W, through spot No. 1, seen by Birtin 1860 and 1863, also by Pratt on April 12, 1870, and March 3, 1871 (see post, pp. 281 and 282). Both in interval 96 to 108 hours. The above enumeration has been drawn up with an especial view to the connexion existing between the spots and streaks. There are a few points worth notice, particularly as regards the streaks: one is, their appearing brightest nearest the border of Plato; another, assuming that they have OBSERVATIONS OF LUNAR OBJECTS. 249 their origin in spots, that they extend from higher to lower ground; and a third, their sharp and definite character on some occasions contrasted with their extreme delicacy on others. Mr. Pratt, under date of November 9, 1869, wrote as follows :—‘ As far as I can remember, I have always forgotten to say how delicate the chief parts of the trident are; they are most delicate.” In the Observers’ Notes (see post, pp. 272 to 298) there are numerous instances recorded of the difficulty of detecting the stem and arms of the trident in the neighbourhood of spot No. 1, and often of their complete disappearance. On the other hand, observers frequently speak of the sharp definition of certain streaks. As regards the connexion between the spots and streaks, in the case of the largest spot, No. 1, which is situated on the highest part of the floor, it appears highly probable that the three arms and stem of the trident are connected with it much in the same way as streams of lava are connected with the volcanic orifice from which they issue; the varying intensity of brightness of the arms is greatly in accordance with the supposition of their being the results of intermittent emanations from an orifice of this kind, of which the cone is spot Nol. The spot ranking next to No. 1 is No. 4, which appears to be of almost the same character as No. 1, the main differ- ence being its frequent hazy appearance, which on some occasions is very marked. From this spot three distinct streams appear to issue :—JFirst, the sector, which is usually seen to spread out from it in a fan-shape ; very rarely the fan of brightness has been seen striped, as if the slope from spot No. 4 to the S.E. border were furrowed. Generally the brightness extends as far as the border, where three spots have been (although rarely) seen; and on one occasion a dark space, as if occasioned by a cloud, covered them. Second, the streak n, extending to the N.E. border : this streak very frequently exhibits, in common with the arms of the trident, a fading of the portion between the cone and the border, so that the portion near the border is usually the brightest. Third, a streak mentioned only as an extension of the sector from spot No. 4 to spot No. 3; it is not often seen. The disposi- tion of the three streams indicates very probably the channels in which any ejecta may have descended from the orifice, and in which such ejecta may have so accumulated as to have produced the appearance of ‘spurs ” noticed by Mr. Pratt (see Report Brit. Assoc. 1871, p. 95). On either side N.W. and S.E. of spot No. 4 are the spots Nos. 3 and 6. The three are situated upon the N.E. slope from the “ fault,” and from No. 3 (which, by the way, is a group of three openings) issues the streak (6, and from No. 6 the streak y. The near parallelism of the streaks 6, n, and y results most probably from the positions which the spots from which they issue occupy on the sloping ground. The north-west part of the floor offers a very decided contrast to every other portion, characterized, as it has been during the two years, by consider- able alternations of brightness, as well as alterations in the forms of the streaks found upon it. The connexion between the spots and streaks, to which attention has been directed, is well marked ; but here in the N.W. area it is difficult to detect such a connexion, if it exists. The principal spots are Nos. 13, 19, and 16 ; and these lie in the principal streak of the district, and do not appear as orifices from which distinct streaks issue. In whatever the peculiarity of this portion of Plato consists, it is one that should be most assiduously watched and every phenomenon witnessed on it most carefully recorded. The observations had proceeded with great care during a period of more than twelve months, when-a new streak made its appearance between spots 250 REPORT—1872. Nos. 5 and 14. Some months afterwards a continuation of this streak east- ward of No. 5 was observed, and very lately it has been seen between Nos. 14 and 22 (9, fig. 1, on p. 247). A very remarkable characteristic of this streak is its parallelism with the south border. Taking all the circumstances of the observations into account, it can scarcely be doubted that this is a new streak, the eastern and western portions being connected with spot No. 5, and the further continuation westward with spot No. 22. If it should be well established that new streaks make their appearance from time to time, we may be able to understand that many recorded differ- ences from the older delineations are to be referred not so much to errors of the earlier selenographers, as to real changes in the objects themselves; for example, this very area of Fig. 2. Plato is figured by Beer and Midler, in the first edition of the large map, as being crossed from N. toS. by four light streaks, as in the annexed sketch, fig. 2. That Madler actually saw these four streaks there can be little doubt, as they are distinctly mentioned in ‘© = ‘Der Mond.’ That they are not in existence at present =2 a is quite certain; for the disposition of the streaks is NOW plato.— Beer and Midler. very different from that figured by Beer and Midler. i 3 INFLUENCE OF THE SUN ON THE Foor oF Prato. Previous to an examination of certain non-periodic changes of brightness, colour, and the forms of streaks, it is essential to ascertain the normal varia- tions of tint as dependent upon the gradual increase and decrease of the sun’s altitude before and after the sun’s meridian passage. This has been ascer- Curve of variation of tint on the floor of Plato. tained by noting the tint of the floor in accordance with the directions specified on the form for receiving the records of the observations. A medium tint has been regarded as the mean line, and its value fixed at 0°50; and as the curve of the sun’s altitude consists of an ascending and a descending OBSERVATIONS OF LUNAR OBJECTS, 251 branch, and also as the floor becomes darker as the sun ascends higher, an ordinary light tint has been fixed at 0°33, and a dark tint at 0-66; very light and very light indeed have been registered provisionally lower than 0:33, and very dark and very dark indeed higher than 0-66, so as to give a range, as regards Plato, of 1:00. The actual range resulting from 133 obser- vations in two years is 0-41, and the range of solar altitude at the equinoxes on the parallel of 50°.is 40°. The chromatic range very nearly coincides with that of altitude, and the connexion between the tint of the floor and the effect either of light or heat is plain and unmistakable. The floor must therefore consist of material capable of becoming darker by exposure to light and heat, or it must possess a covering that may possibly be affected in the same way. The inflexions of the chromatic curve indicate rather considerable variability, especially in the deepening of the tint, which hardly accords with a permanent surface being heated by definite and regular increments of heat: and it would also appear that the solar effect is not fully attained; for although the ranges of both curves are very nearly equal, a mean chromatic curve drawn with a free hand would indicate an average lighter floor than that which a regular heating might be expected to produce. So far as the writer is aware, this is the first attempt to indicate numerically the chromatic effect of light or heat, or both, upon the moon’s surface. It has long been known that the grey plains appear darkest under a high sun, but the knowledge of the nature of the progression has been vague and undefined. It is greatly to be desired that other spots, especially in lower latitudes, should be observed in the same way; but some time must necessarily elapse before observations of them could be compared with those of Plato. II. An EXAMINATION OF CHANGES RECORDED IN Avuaust 1869. These changes were recorded in four carefully executed drawings of the floor of Plato by Mr. Pratt. They exhibit, first, a rapid alteration of the distribution of the light and dark portions of the floor between the 16th and 17th of August, and a more gradual but slight, yet still perceptible, change from the 17th to the 28th. Calling the figures in their order 4, 5, 6, and 7, and starting with the assumption that the permanent colour of the floor is light (see Section on the influence of the sun on the floor of Plato), we may trace the changes between each of the observations, remarking at the outset that the spots are presumed to be permanent as to their positions on the floor. Fig. 4, August 16, 1869, exhibits a disposition of the darker shading entirely detached from the border on every side. The shape is roughly that of a W,—the western leg being the widest, with spots Nos. 14, 1, and 19 just on its border; the dark space forming the middle leg extending from beyond No. 17 to beyond No. 3, both spots being involved in it; and the eastern leg very near the east border, having spot No. 6 on its western edge. Seven spots are given on the drawing, viz. Nos. 14, 1, 6, and 19, just on the border of the darker portion, Nos. 3 and 17 in its midst, and No. 4 on the light portion. Theorizing merely as a help to connect and interpret the phenomena observed, and assuming that the lighter tint is that of the floor and the dark tint that of a something which varies in position, the nature of which we have yet to learn, we have in fig. 4 its disposition on August 16, 1869. Of the shading of the floor on this day Mr. Pratt thus writes :—“ This was more 252 REPORT—1872. curious than I had seen it before, and totally different from my former sketches.” Fig. 5, August 17, 1869.—In this figure we see a very considerable exten- sion of the dark portion of the floor, the spot No. 6 still marking the position Fig. 4. | ‘Fig. 5. it iw ' Plato, 1869, August 16.—H. Pratt. Plato, 1869, August 17.—H. Pratt. of the western edge of the eastern leg of the W of the 16th. On the 17th we find this leg had extended quite to the eastern border; indeed the whole of the northern boundary of the dark portion had become extended to the N., N.W., and W. border ; at the same time the opening between the eastern and middle legs unveiling the lighter floor (?) had become extended, so as to include spots Nos. 3 and 19, and to exhibit (?) spot No. 13. If this were so, it could only have been effected by a separation of the darker substance, whatever it was, which, spreading outwards towards the border of Plato, pro- duced the different configuration observed on the 17th. This opening from the §.W. part of the floor to the east border and sector was seen by Mr. Gledhill on September 25, 1869 (see post, p. 295, and fig. 9, p. 263). In the southern part of the floor we have another opening, apparently in the neighbourhood of spot No. 1, which joined the opening effected in the northern part at its western end, the N.W. arm of trident e; and, simultane- ously with this opening, the dark substance near spot No. 3 overspread a portion of the opening between the western and middle legs, by which the stem and north-western arm of the trident was produced. That part of the darker portion just 8.W. of spot No. 1 must have under- gone the greatest change in its disposition, inasmuch as not only was an opening made from No. 1 to beyond No. 14, but the substance itself must have increased ; for there can be no doubt that the area covered by the darker portion on the 17th exceeded that covered on the 16th. The effect of this extension was the production of the S.E. and middle arms of the trident, or, at least, the rendering of them apparent as compared with the 16th. Looking at the position of spot No. 1 in connexion with the three arms of the trident, can it be possible that emanations from this crater tended to preserve the radiating openings marked by the figure so well observed from the 17th to the 28th inclusive ? In reference to August 17, Mr. Pratt has the following remarks :—‘ This {the floor] was very remarkable: resolved to give it especial attention, and, after some application, succeeded in adding piece to piece till a sketch was OBSERVATIONS OF LUNAR OBJECTS. 253 completed, very strange in comparison with last night’s sketch. Its form, complicated as it was, was very carefully traced in the drawing, and repeat- edly seen afterwards, but so delicate that it was impossible to see the whole at once. It required to be traced out by minute attention.” Compare Mr. Pratt’s drawings (figs. 5, 6, and 7) with Mr, Gledhill’s of September 25 (fig. 9, post,.p. 263). In comparing Mr. Pratt’s sketches of August 16 and 17, the transition in the 25 hours is very remarkable; indeed so much so as to indicate that some extraordinary change had come over the floor in the interim: the disposition of light and dark is almost entirely different, yet I think I can trace the effect of “action” on the floor. On the 16th the lighter portion affected the border, the darker portion being entirely separated from it. The northern boundary of the dark portion took the form of the streak ¢ and «, which was plainly seen on the 17th, with a dark portion on its north. Had the streak c and « a motion southward from the north border between the two observa- tions? Again, on the 17th, e, the N.W. arm of the trident, was not sepa- rated from c. It would appear that the markings, as seen on the 17th, were evolved, from the peculiar and remarkable disposition of the light and dark portions seen on the 16th. It will be seen further on that, as the observa- tions proceeded, the light portion was not unfrequently noticed to be in con- tact with the north border. 1869, August 20.—Mr. Gledhill described the floor as darker than the surface of any of the Maria=0-99 ; the sector faint and all spots faint. On the same day Mr. Pratt thus graphically describes his seeings:—*“ The shading on the floor of Plato is quite a study, and a perplexing one; some- times, when the air is disturbed, a light sector (S.E. part), like Mr. Birt’s key-plan, is alone visible. Again, in a few minutes two streaks from Anaxa- goras would seem to cross the floor, as sketch May 22, 1869 ; then, again, between the two, a third narrower streak appeared, similar to Webb’s copy in ‘ Celestial Objects ;’ and as definition improved, a light marking near the north rim («) was seen; and again a change, and the appearance is decidedly the same as on the 17th of August, a near approach to Mr. Knott’s sketch. “These different appearances were reobserved, in all their curious dis- solying-view-like changes, several times over, thus beautifully showing the harmony that may possibly exist between the most dissimilar observations, and strongly suggestive (to my own mind) that the form of the shading on the floor is permanent, and that the various degrees of visibility of its more difficult features is owing to the relative changes in the medium through which we see it—whether of the earth’s atmosphere alone, or of an obscuring medium on the floor itself, must be determined by comparison with similar and simultaneous observations in different parts of the world. Thus within two hours I several times saw four greatly differing aspects of the shading on the floor, viz. B. & M.’s, Mr. Birt’s, Mr. Knott’s, and my own.” 1869, August 21.—Mr. Gledhill recorded the tint of floor as dark as that of the Mare Crisium, and that the light sector was fairly seen. Fig. 6, August 23, 1869.—We find in this figure the extension and gathering up of the dark portion still in progress, although to a very small extent as compared with the “action” of the 16th to 17th. The northern light portion was seen separated from the N.W. arm of the trident, and an opening made from spot No. 6 to the 8.E. border, apparently by the action of the spot. Some additional spots were seen on the 23rd—viz. No. 5 on the west border of the S.E. arm of the trident, No. 22 on the N.W. arm, No. 16 on the northern opening, and No. 7 near the east border. 254 REPORT—1872., On this day (August 23) Mr. Gledhill described the bounding lines of the light sector, when produced, as cutting two craters outside and above Plato, and the sector itself as “faint, but luminous and well seen.” Mr. Pratt’s record is as follows :—‘‘ The floor was seen as on the 20th inst., similar to Mr. Knott’s; other markings of a more complicated character were very Fig. 7. yf = == = = b = =O5 = == — — 22 = SS 07 — = 1... . Or 4 ——— b a 190 = 30> = 160 ek Q Plato, 1869, August 23.—H. Pratt. Plato, 1869, August 28.—H. Pratt. strongly suspected. The trident-shaped marking a little more slender and elongated N.E. and 8.W. than in my sketch of the 20th inst., probably an error in drawing its first appearance. On this drawing I have the following remark :—‘ N.W. arm of trident separated from curved streak by a narrow neck of dark surface. The stem as on the 17th.’”’ 1869, August 25.—Mr. Gledhill described the floor as “not so dark as the upper part of Grimaldi.” 1869, August 26.—Mr. Pratt writes: “ Shading on floor visible, precisely as in sketch of the 23rd of August, 1869—~viz. the long streak from the N.W. round by N. and crossing 8.E., with the ray / towards the middle of II E ¥ ’, and the trident-shaped marking on the 8.W. part of the floor, with the streak [stem of trident, d] extending halfway from spot No.1 to No. 4.” 1869, August 27.—Mr. Gledhill described the light sector as a very faint object. Spot No. 3 easily seen double, and the floor but little darker than the Mare Imbrium. 1869, August 28.—Mr. Pratt’s record is as follows:—‘The shading of the floor was seen as on the 23rd of August, with the addition of the apparent continuation of the streak (d) from spot No. 1 to spot No. 4, and a curved streak commencing abruptly at the shadow of the rock Rupes Smythii (B. & M.’s Z), not sketched, and continued towards spot No. 3, and joining the streak along the north side of the floor.” These features are exhibited in fig. 7; the opening forming the stem of the trident is seen extending as far as the “Sector,” and a new opening, apparently a continuation of the northern opening, extending north of spot No. 7 towards the east border. The hypothesis suggested as an explanation of the variations depicted in Mr. Pratt’s drawings recognizes the darker portion of the floor as possessing an obscuring character, and subject to changes which do not affect the lighter. Although looking at this hypothesis, as set forth in the above remarks, as explaining the variations observed by Mr. Pratt, yet it is difficult to divine the nature of the darker portion, as it appears to absorb light rather than reflect it. It is noteworthy that it is the darker portion of the floor that OBSERVATIONS OF LUNAR OBJECTS. 255 varies its tint to the greatest extent. There are further phenomena which require explanation ; neither the light nor the dark tints are seen at sunrise or sunset, but a greenish tint characterizes the floor at those times. It is when the sun attains an altitude of 30° that both the light and dark tints appear; and it has been especially noted that when the craterlets assume the appearance of white spots, the sun is usually about 30° high. All the phenomena hitherto observed on Plato, except the variations in the visibility of the spots, and, it may be, in the visibility of the streaks also, depend upon solar influence. In order to guide future inquiry, it may probably be useful to present an enunciation of the principal features of the hypothesis employed in explain- ing the above-recorded variations as bearing upon the lighter and darker markings of lunar plains generally. The hypothesis is based upon the known properties of gases and their affections by heat. Being well acquainted with phenomena, the proximate causes of which are understood, we may proceed to the study of other pheno- mena of which the loci are inaccessible to us, but which, being knowable, we may also, by observation and induction, become acquainted with their causes. We know that the effect of heat on all bodies whatever is to vaporize them, and this vaporization proceeds at all temperatures, low as well as high. We also know that vapours behave as permanent gases, are diffused through them, are elastic like them, and are expanded as they are by successive in- crements of heat. We further now that vapours of even solid substances attain a state of maximum density in given volumes of gases dependent upon temperature ; and our knowledge extends a step further, viz. that when the temperature of a given volume of gas is diminished below the point of maximum density of any particular vapour, the superabundant vapour is condensed and cloud or dew are formed, and this alike of metallic as well as of liquid substances. Now, bearing in mind these four results cognizant by us, the conclusion seems to be irresistible,—(1) that the sun shining on the moon’s surface must vaporize the materials of which it is composed ; (2) that the vapours thus raised from the surface must be dissimilar, inasmuch as the different reflective powers of different parts of the surface indicate the existence of different materials composing the surface; (3) that the different vapours resting on the solid surface act upon each other and upon the ma- terials of the surface itself, so that diffusion takes place, and maximum den- sities are attained as the temperature both of the surface and of the vapours increase; (4) that the expansibility of the vapours raised above the surface by the accumulated heat of at least 177 hours of uninterrupted sunshine must produce ascensional currents of the liberated vapours, carrying them into colder regions, where condensation occurs, and cloud or mist is formed ; (5) that the attraction of gravitation acting on the condensed vapours causes them to descend into warmer regions, where they are dissolved; and as the temperature declines less vapour is raised, and the features of the surface become unobscured. A very pertinent question may here be asked. Is this hypothesis capable of substantiation, or, upon examination, is it likely to be found destitute of proof? In reply it may be asked, Do the darker markings, which appear to be formed some time after sunrise upon the floor of Plato, partake of the nature of clouds? and are these clouds perforated and separated by elastic vapours rising from a surface heated by an exposure to sunlight of 48 hours or more, in consequence of which its reflective powers become stronger, pro- 256 REPORT—1872. ducing the lower lighter surface? The difficulty in this supposition is the dark upper surfaces of the hypothetical clouds. If we can find a vapour which, when illuminated by the sun, appears darker than the ordinary sur- face of a cloud of condensed aqueous yapour in sunlight (which, by the way, shines with about the same luminous intensity as the moon’s surface), we shall be in a fair way of explaining the difficulty. The green colour which is witnessed at sunrise and sunset is probably the natural colour of the floor of Plato, which, under the accumulated heat of the solar rays, reflects a lighter tint ; at the same time the condensed vapour overspreads the lighter floor below, giving rise to the appearances we witness. In applying this hypothesis to the explanation of the phenomena presented by Linné, it is necessary to remark that we have a shallow basin surround- ing a cone. The earliest appearance is that of the cone standing out from the dark surface around, the next of a white spot, more or less of a cloudy character, surrounding and hiding the cone. If the above-enunciated hypo- thesis be correct, it would explain the Linné phenomena thus—at sunrise the features are well marked, as neither a liberation of gas nor its condensa- tion has taken place: as the sun’s altitude increases, the surface around Linné becomes heated, reflects more light, and a spot is formed at the same time in the lower levels; the condensation of liberated vapour not far above the surface produces the generally observed dark appearance of the Mare, obscuring on many occasions spots and craters. The remarkable instance of the contraction of the white spot around Linné in June 1867 may be explained by the condensed vapour rising higher, so as to leave a smaller area of the upper part of the cone visible; or if it were at an elevation equal to about the summit of the cone of Linné, a partial cessation of the liberation of elastic vapour would allow it to gather around the cone, to be dispersed by a further eruption of vapour or gas from the orifice of the cone. On the 22nd of September, 1871, I received a letter from Mr. Elger, in which he says :—‘“ Your letter of the 18th, relating to the markings on the floor of Plato, has greatly interested me, inasmuch as you therein suggest a theory to account for the remarkable appearances observed, which seems to me to be well worth careful consideration. Doubtless the sun’s heat during the long lunar day must cause vaporization on the moon’s surface, and sub- sequent condensation of the various vapours raised follows as a matter of course. So far we have a vera causa which would account for a great deal, if we could only show that the vapours raised are sufficiently dense to produce VISIBLE effects: it is highly probable that they are so, or, at all events, we may suppose that the varying visibility of such delicate objects as the spots on the floor of Plato is, to a certain extent, accounted for in this way; but I would submit that, in the case of the markings, it is difficult (if the dark spaces between the markings are the upper surfaces of masses of vapour hovering over the floor, and of course varying in altitude from hour to hour) to account for the fact, that since the year 1866 the light streaks have altered so little in shape and position. It seems to me that if they were merely openings in the dense vapour, they would not only vary in position from lunation to lunation, but changes would take place from hour to hour, which could hardly be overlooked by observers with powerful instruments: Linné is a case in point. The observation of June 1867 is in perfect har- mony with your theory; indeed the phenomena presented by this remark- able formation are, I think, quite inexplicable, except by supposing agencies of the kind suggested by you to be in operation. At some future time, when selenography is more advanced, it will probably be found that all OBSERVATIONS OF LUNAR OBJECTS. 257 objects on the Maria and low-lying tracts are more or less variable in visibility.” In reference to Mr. Elger’s remarks, an important question may be sug- gested. Is the moon surrounded by an atmosphere of elastic gas? This question has been answered in the negative, inasmuch as in the phenomena of occultations no distortion or bending of the rays of light from the stars occulted has been noticed. If I remember rightly, this is the basis of the negation: Mr. (now Sir W. R.) Grove, in his address to the members of the British Association at Nottingham in 1866, alluded to the unsolved state of the question ; and, “supposing the moon to be constituted of similar materials to the earth, it must be,” he said, “doubtful if there is oxygen enough to oxidize the metals of which she is composed; * * * and it might be a fair subject of inquiry whether, if there be any coating of oxide, it may not be so thin as not to disguise the form of the congealed metallic masses, as they may have set in cooling from igneous fusion.” The presence of oxygen, in- ferred from oxidation, presupposes an atmosphere of permanently elastic gas or gases. From the investigations of Herr Althaus, it has been approxi- mately estimated that the moon’s hemisphere turned towards the earth attains at least a maximum temperature of 840° of Fahrenheit, upon the assumption that the moon’s power of absorbing heat is equal to that of quartz. The heat thus attained would very closely approximate to the temperature at which iron appears red in twilight, and exceeds the fusing-points of tin and lead. On the other hand, the minimum is estimated to be —92° of Fahren- heit, which would give a fall of about 940° in fifteen days; this would be equivalent to daily increments and decrements of heat of about 63° each. This enormous variation must be attended with very considerable expansion and contraction of the gases, either present or liberated, and a very rapid diminution of temperature upward must result. Now about the period of maximum temperature of the luni-solar day the surface, whatever materials may compose it, must be in a very different condition to what it existed in at sunrise; and this is so far visible to us by the different aspects of objects under high illumination, so graphically described by Webb, and also by the intensely glowing luminous spots, such as Aristarchus, Censorinus, Dionysius, and various streaks under a midday sun. If the heat exceeds the melting- points of tin and lead, it is quite possible that, long before the maximum tem- perature is attained, substances may be fused and vapours given off which, rising quickly to a cooler region, may be condensed and become visible to us as cloud. As regards the streaks on Plato, it has been proved by observation that the floor is irregular, although it generally appears to be smooth and even ; it is known in some places to rise slightly above a mean level and to sink in others slightly below ; and this depressed character is most prominent at the interior foot of the surrounding mountain-ring. The principal craterlet is situated upon the highest part of the floor, and from it radiate the arms and stem of the “trident.” It is not at all unlikely that the great heat to which the surface is subject may at times produce eruptions from this and other eraterlets ; indeed we appear to possess evidence that this has actually taken place at least twice within the period of the observations; and the arms, as well as the sector and great northern streak, may owe their existence to such eruptions, which of course would give them a permanent character. Sub- jected to the intense cold of the lunar night, at sunrise they would only reflect the same amount of light as the other portions of the floor; but as the floor —_— unequally heated, some portions absorbing heat while others 1872, T 258 REPORT—1872. reflect more light, they would stand out as luminous streaks and markings, to be partially or’ wholly obscured by any condensed vapour which may happen to be floating above them. An absence of condensed vapour would impart to the floor a sharpness and definiteness so often observed, by the aid of which very minute objects are easily seen, while even a slight film, ana- logous to our cirrostratus cloud, would impart a mistiness by which the more delicate spots and streaks would be obscured, the broader features still re- maining visible—a state of things of which evidence exists in the observations, and which has been observed more or less since the time of Heyelius, who relates that ‘several times he found, in skies perfectly clear, when even stars of the sixth and seventh magnitudes were visible, that at the same altitude ot the moon, the same elongation from the earth, and with one and the same telescope the moon and its maculz did not appear equally lucid, clear, and conspicuous at all times, but were much brighter and more distinct at some times than at others.” In a letter written under date of September 27, 1871, the Rev. T. W. Webb suggests that there is more inequality than we have yet studied in the reflective power of different substances at different angles of illumination or incident light. “It may be,” he says, “that different colours behave differently when treated in this way ; and I suspect they do: ¢.g., if from the surfaces of certain materials the capacity for reflection of blue rays should increase more rapidly than that for red, then with increasing angle of illumi- nation the colour of the object would slightly change, and with it its propor- tional visibility at a distance where colour becomes imperceptible. * * * Is it not possible that other circumscribed regions in the moon, e.g. that glorious Archimedes, might show variations in the markings eyen more defi- nite and considerably more easily dealt with than those in Plato? The curiously but occasionally speckled and streaky aspect of the Mare Crisium, as described by Schroter, B. & M., and others, would be a grand case were it not so rare. If we could only find some smaller and more easily studied surface, equally or more frequently varied, it would be a great matter. But is there not something of a more general character underlying, as it were, these special instances that has never yet been properly investigated? We lay it down, as if it were unquestionable, that local colour in the moon is masked in the rising and setting illumination, and comes out under high angles when the shadows disappear. It may be so; but why? IfI took a piece of plaster of Paris, moulded it into all sorts of hollows and knobs, and painted it harlequin fashion, then the colouring would be all equally visible, whether under oblique or vertical illumination; or, to make it more like the moon, if the artificial surface were only shaded with brownish or bluish greys we should have the same effect; as long as there was light enough to show it, the distinction of colour would remain. On the moon it is far less evi- dent, and frequently quite imperceptible. Now what underlies this? Why do certain very dark spots on the moon come out under high illumination, or certain brilliant specks, being much less if at all contrasted with the neighbourhood when near the terminator? Could we produce an artificial surface which would behave in the same way? Why should this difference (whatever may be its cause) depend, not on the angle of incidence, but on that of reflection ; for the full-moon aspect extends over the whole disk, not- withstanding the low illumination of the regions all round the limb, many of which show spots as vivid or as deep as more central regions? No one, so far as I know, has touched at all on this very interesting point.” Mr. Webb’s suggestions and queries are very important. On that of an OBSERVATIONS OF LUNAR OBJECTS. 259 irregular surface painted with different colours presenting an equally diversi- fied appearance, whether the incident light were oblique or vertical, and the distinction of colour remaining so long as sufficient light existed to show it, I would remark that there can be no doubt that the moon’s surface is as much variegated with colour as the earth’s, but by distance the distinction of colour is softened down to tones of grey, in the same manner as we are able to distinguish nothing but greys in a distant terrestrial landscape. It is the telescope which brings out the distant red-brick building or the dazzling whiteness of the church steeple under a noonday sun, the predominant colour of the landscape being either the delicate green of spring, the deeper green verging on blackness in summer, or the rich reds, browns, or yellows of autumn. These are the colours which characterize the foliated covering of the earth, interspersed with a sandy or even white tint indicative of the ex- istence of vast desert tracts. At the distance of the moon we only perceive on her surface various tints, from a dark blackish grey to a dazzling white ; and these are certainly intensified under vertical illumination, but most decidedly under that reflecting angle the value of which is measured by the supplement of the difference of longitude of the moon and sun when it is equal to zero, or supplement ( —©=0°. Perhaps the following experiment may set this matter in a clearer light. Take an ordinary cream-coloured envelope and place within it a piece of bluish paper, so that the two tints may appear in juxtaposition, also a piece on which various shades of grey have been dabbed, as trials used in colouring. If these are held or placed in such a position that very oblique light may fall upon them from a lamp, although the distinction of colour may be perceptible, it will be, under the earliest illumination, so very slight as to be hardly cognizable if viewed from an angular position equal to the supplement of 90°: 7. ¢. let the lines from the lamp to the illuminated surface just grazed by the incident rays and from the same surface to the eye form an angle of 90°; now let the lamp, eye, and illuminated surface be brought into the same plane, although not into the same line, and it will be found that the tints become much more distinct. No more light falls upon the surface than before ; but the eye views the surface under a different disposition of the angles of incidence and reflec- tion, the consequence being a better appreciation of its inherent light and shade. By placing the different shaded papers in such a position that the light from the lamp falls perpendicularly upon them, and bringing the eye as nearly as possible into the same perpendicular line, we view the paper as we view the full moon, the tints coming out in the strongest manner possible ; and this is in accordance with the law that the greatest quantity of light is irregularly reflected with the smallest angle of incidence. As the diameter of the moon subtends a maximum angle of less than thirty-three minutes of are, the rays coming or reflected from her are nearly parallel ; from which it follows that the path of the solar rays impinging on the moon, and passing to the earth, will be nearly as the sides containing the angle known as the supplement of the moon’s elongation from the sun, which at full eeuals 0°. In applying our experiment to the moon in all its generality, we ought to have a regular increase and decrease of intensity of tint, subject to small but also to very regular variations. Is it so? In one remarkable and well!- observed instance, at so early a period as twenty-four to thirty-six hours after sunrise on Plato, the north-west portion of the floor was so strongly illuminated as to obliterate the well-known north-west streak. This appeared to be an abnormal brightening of the floor, and must have been quite inde- pendent of illuminating or reflecting angle; its bearing upon pe Pratt’s T 260 REPORT—1872. remarks relative to an unusual exhalation of vapour causing an extension of lucid area (see post, p. 261) or a flowing together of neighbouring light-streaks is obvious. On the 12th of May, 1870 (the brightening of the floor was ob- served on the 9th of May), it had so far subsided as to allow of the north-west streak being seen, one observer (Mr. Gledhill) recording it as the brightest on the floor, another (Mr. Elger) registering the part east of spot No. 16 as very bright and well defined. This was from 96 to 108 hours after sunrise. That this increase of light was independent of either illumination or reflec- tion, except as transmitting agents, is evident from the fact that at the same interval from sunrise, 96 to 108 hours on the 14th of March, 1870, the eastern arm of the “ trident ” was recorded as the brightest marking. Mr. Pratt, writing under dates October 17 and 18, 1871, says :—‘ A year or two since I was reading Kirchhoff’s ‘ Memoirs,’ Roscoe’s ‘Spectrum Analysis,’ and several other works on the subject, and at the same time frequently spent an evening in Mr. Mayall’s laboratory with his splendid spectroscope. About that time I often considered the possibility of vapours rising from the heated surface of the moon, and wondered if the dark spaces were in any way absorptive clouds, and became of the opinion, and am s0 still, that both the darkest and the lightest markings on the surface may be but the appearances of vapours..... Looking at Proclus, Aristarchus, and the interior of Tycho, I can never feel certain that their brilliancy is merely the dazzling reflection from naked rocks; and that great valley running N.E. from Tycho suggests other causes for its whiteness than merely different incident and reflecting angles and different materials of its soil. The Mare Frigoris has very often suggested to me (and I have mentioned the same to you more than once) both the possibility and probability of its being covered with some- thing very foggy in its nature. It has frequently had that appearance in my telescope; and while objects on the heights of the rim of Plato have been well defined, a general haziness has belonged to those on the Mare below,— full proof, I think, that the obscuration not only belonged to the moon itself, but was confined to its lower levels. That under the circumstances the intense heat must produce vapours from the surface, even if small in quantity, and that, once produced, they must act as your theory supposes, seems incon- trovertible.. Some visible effects of their production, both in absorption and reflection of solar rays, must follow as a natural consequence; and if those instances you have thought proper to adduce are not real observations of those visible effects, it remains for some more assiduous observers to bring forward more complete proof of their presence; but I cannot then see that even the supposed presence of such vapours is in the least degree negatived. The proof of their presence by observation of their effects would only be in abeyance. Does not the softened margins of light-streaks generally on the moon suggest a vaporous origin? Surely, in the case of Linné, it is as reason- able as that the white spot arises from reflection from a surface of shivered glass. The past observations of Linné and your present theory fit well to- gether; and it seems to me that if one may be forgiven for supposing the presence of a small quantity of moisture on the moon, then the hotter the surface the whiter the spots and streaks would become to our view.” [In reference to Mr. Pratt’s remark on the whiteness of the heated surface, TJ may call to mind the appearance of slated roofs under a July or August sun which I have noticed. It is just as if the slates had been coated with a white pigment. Instead of a dark slaty hue they have presented a strongly decided white, so as to induce the belief that the roof had been whitewashed or painted white. Having given some attention lately to the so-called irregular OBSERVATIONS OF LUNAR OBJECTS. 261 reflection of light, in connexion with the above remark I may notice that an increase of light from dark slated roofs is observed as the sun approaches such a position in the heavens, with regard to the eye, that if the roofs con- sisted of polished surfaces an image of the sun would be seen at the moment when the angle of reflection equalled the angle of incidence ; and this tendency to the formation of an image is greatly augmented by a falling shower, the rain bringing the slates more into the condition of a watery surface, rendering them comparatively darker, except at those points where the two angles meet. Irregular and roughened surfaces on the moon will consequently appear brighter at those periods in the lunation when the light from the sun to the moon, and thence to the eye, falls in the lines of incidence and reflection. At all times irregular reflection from the moon is independent of the incident rays; but an approach to regular reflection attended with increase of light, the epoch of which for each point of the moon’s surface is clearly calculable, must occur during every lunation, so that all normal brightening may be easily detected. ] “ Starting from the hypothesis, it seems to me that your explanation of the variation of position of the light-streaks must be held a very reasonable one ; and I beg to add a small supplement. I suppose that the maxima of midday heat at the latitude of Plato are not always the same, that they run through a slight seasonal variation, then a periodical difference in the quantity of vapour raised would result ; and if the general outline of the light-streaks is the result of the local conformation of the ground as related to the craterlets, then an unusual amount of vapour raised;might cause two or more light- streaks apparently to flow together for a time, producing an entire change in their outline, afterwards, as the heat lessened, to resume their most usual appearance. I have often thought the light-streaks suggested the remem- brance of the mists and fogs which may be seen on an autumnal evening from the elevated parts of our downs; as evening advances the mists gradu- ally appear winding about in streaky shapes or isolated in irregular patches, according to the formation of the ground, while their margins, sometimes sharp, are generally soft and ill-defined, very much like lunar light-streaks to my mind, if they could be seen from a nearly perpendicular direction. «There is a difficulty as to the nature of the dark tints, supposing them to be cloudy coverings; but is it quite certain that the middle tint is really the true colour of the soil? What if the darkest tint was the colour of the naked surface, and if the middle tint, which appears at sunrise and sunset, is a covering of the nature of hoar frost, the vapour which is supposed to be raised during the luni-solar day freezing again on the sudden approach of night? But we are supposing the presence of moisture on the moon. We must not forget the Baconian maxim.” [Mr. Pratt’s idea of hoar fr ost is very su ggestive; not that the appearance of the surface near the terminator is of that nature in the sense in which we employ the term, for one would think that then the reflected light would be most certainly white ; yet it cannot be denied that, generally speaking, within about 10° of the terminator, the surface of the moon is such as we may suppose that of the earth to present after a cold clear frosty night, the atmo- sphere being exceedingly translucent, so that objects are readily and clearly visible. The lunar night must be intensely cold, with enormous radiation, by which, whatever gas or vapour may exist, both its bulk and elasticity would be greatly reduced, especially towards sunrise; so that it is quite possible that an atmosphere, if such there be, would be of the rarest charac- ter, and this would fully account for the clearness and sharpness of objects at 262 . REPORT—1872. sunrise. Upon the supposition of the existence of an atmosphere, and of the exhalations arising from the intensely heating of the surface as the sun ‘approached the meridian, at a distance beyond 10° from the terminator, in the absence of dense clouds, we may have an undefined mistiness not fully and entirely obscuring objects nor interfering with their distinct outlines, yet rendering their aspects different as compared with those which they present when they emerge from night. And this difference of aspect may not only be increasing up to the epoch of maximum temperature, but diver- gent, inasmuch as various substances will be variously affected by the degrees of heat to which they may be subjected, some darkening under the intensity of the solar rays, others behaving in quite the opposite manner and exhibiting something like dwminosity, arising, perhaps, from heat-rays reverberated from the sides of craters as the sun shines almost perpendicularly upon them. That phenomena of the kind just alluded to are clearly recognizable upon the moon there can be no question. We have only to read Webb’s masterly exposition of the progression of appearances during the luni-solar day to be convinced that some such agencies as we have here supposed must be at work. Oi ihe probable success of continued observation of minute objects Mr. Pratt writes :—‘‘ It has long appeared to me a reasonable expectation that the effects of such a low-lying atmosphere (as only could be supposed) would be much more visible in the search for minute detail on the surface than in the observation of occulations; while the former method might be expected to yield results much more rapidly than the latter, as the duration of the maximum effect to be expected in the latter case could not be much greater than a second of time, while in the former case it might be observed con- stantly for hours at a time,” ng) FP History oF STREAK a, WITH ITS ADJUNCTS, ON THE Nortr anp Norru-west Froor or Prato. Lunation September 1869, from 9 hours before meridian to 12 hours before sunset, This streak was not observed until the 20th of September, 1869, when it was first seen by Mr. Elger (see fig. 8). It is figured by him as a short, straight, narrow streak, stretching across the north-west part of the floor, and forming, if produced, an acute angle with the longest diameter of Plato drawn through spots Nos. 1 and 4. On the 25th of September, five days later, Mr. Gledhill observed the streak, its form and direction being nearly iden- tical with those of the streak seen by Mr. Elger. For the general distribu- tion of streaks on the floor see fig. 9 and ‘* Observers’ Notes,” interval 72 to 60 hours, post, p. 295. On the 27th of September, near sunset, interval 24 to 12 hours, the streak was seemingly lost, as Mr. Gledhill records only the streak ¢ as a broad band of brightness, in width about one third the distance from the north rim to spot No.1; nor does he specify it separately on October 27, 1869, under the same interval 24 to 12 hours. Lunation October 1869, from 69 hours before meridian to sunset. In this lunation the streak was picked up by Mr. Gledhill in the interval 108 to 120 hours, covering spots 13, 19, and 16 ; he aligned it, and found that if produced it would cut the north border of B. and M.’s A (438, Webb’s third edition of ‘Celestial Objects’). On this occasion it was deemed advisable to OBSERVATIONS OF LUNAR OBJECTS. 263 divide it into two separate streaks, that east of spot No. 16 being designated “a,” the western part “o.” On October 19 Mr. Gledhill delineated it as a narrow streak (see fig. 17, p. 288); but as he omitted the western part of the Fig. 8. Plato, 1869, Sept. 20.—T. G. E. Elger. Plato, 1859, Sept. 25.—J. Gledhill. floor it is uncertain if the continuation reached the border. On the 21st it was recorded as brighter than on the 19th. On the 25th a dark space was seen between it and the border; and it was observed by Mr. Gledhill on the 26th and on the 27th, in the interval between 12 hours and sunset. Lunation November 1869, from 117 hours before to 21 hours after meridian. On November 14, at an earlier epoch than it had hitherto been observed, Mr. Gledhill recorded the streak as seen east of spot No. 16, the western part “o” being absent. On January 12 Mr. Elger (same interval, 60 to 72 hours) showed in his drawing the continuation “0,” with an extension of its north-west border to the north-west border of Plato, 7. e. the floor from the south-east border of “‘o” to the rim of the crater was equally bright ; this brightness commenced on the east at Webb’s elbow. On the 19th of No- vember the continuation “o” was observed contemporaneously with ¢, which reached nearly to 6, and was convex towards the border. This is in contrast with later observations, in which ¢ was seen concave towards the border (see lunation April 1870, post, p. 264). The contemporaneity of ¢ and “0” indicates that a change had supervened between the first observation in September and November 19, on which day Mr. Gledhill recorded a as tho brightest streak on the floor, and first observed Webb’s elbow. Lunation December 1869, from interval 24 to 36 hours after sunrise to interval i 48 to 36 hours before sunset. This lunation afforded as many as ten observations of Plato, so that the progression of the illumination of the streak could be well traced. At first, on the 12th, it was seen with difficulty, the north-west part of the floor being brightest. On the 13th it was still difficult to separate from the north and north-west part of the floor ; but on the 14th it was seen continued in “0,” the two forming the brightest and best-defined streak on the floor. Interval 72, to 84 hours. ‘The observations of December 12 and 13 are the earliest of the bright north-west floor, which would, from its dip towards the border, reflect more light soon after sunrise than at a later period of the luni-solar day; and it may have been from this circumstance that the brightness of the streak merged into that of the floor. It is, however, noteworthy that on February 9, 1870, interval 24 to 36 hours after sunrise, the streak a should 264 REPORT—1872. have been seen as a sharp narrow bright streak, from the tip of the most northern shadow to the north-east border nearly parallel with a line through spots Nos. 1 and 4, and no mention of a bright floor in its neighbourhood. On December 15, interval 96 to 108 hours after sunrise, the continuation 9” was seen “fairly bright,” but on the 17th it was not recorded; a new phase, however, was noticed, viz. Webb’s elbow, which was continued in c, terminating the streak recorded as very bright on the west. This phase was more fully developed on April 14, 1870. The brightness of the streak con- tinued from December 17 to December 24; indeed it was recorded as the brightest on December 21, 22, and 24, LIunation January 1870, from 36 hours after sunrise to 33 hours before meridian passage. On January 11, 1870, 36 to 48 hours after sunrise, the streak was well seen, its brightness blending with the bright north-west floor. On the 12th, 14th, and 15th, the continuation “0” was observed. On the 15th, 132 to 144 hours after sunrise, the streak a, which extended from Webb’s elbow, was quite separated from the border. LIunation February 1870, from 24 hours after sunrise to 69 hours before meridian passage. On February 9, interval 24 to 36 hours after sunrise, as remarked under the December lunation, the streak was recorded as “sharp, narrow, and bright.” Either the streak must have been brighter than in December, as seen during the same interval, or the floor darker; whichever of the two was the real state, the difference is not explicable on a change of illuminating angle, the altitude of the sun being the same both in December and February. On February 11 and 12 the streak was well seen, being recorded as very broad and bright on the 12th. Lunation March 1870, from meridian passage to 24 hours before sunset. The observations during this lunation were made under the reverse light, i. €. after meridian passage. On the 17th and 19th of March the streak a and the sector were the brightest markings on the floor. On the 23rd, under a declining sun, the streak appeared diffuse and extending up to the north border. ‘This is remarkable, and indicative of the brightness not being due to illuminating angle, which, from the slope towards the north-west border being turned from the sun, would render the floor darker as seen by Mr. Pratt on August 28, 1869, and by Mr. Gledhill on March 24 and Novem- ber 15, 1870. (See Report Brit. Assoc. 1871, pp. 86, 87.) Lunation April 1870, from 36 hours after sunrise to 45 hours after meridian passage. The principal feature in the earlier observations of this lunation is the indefiniteness of the continuation ‘0’ which appears in Mr. Elger’s sketch of April 10 (see fig. 12, post, p. 275), but was not seen by Mr. Gledhill as a distinct sharp streak on that day. On the 11th it was very hazy and ill- defined. On April 14, interval 132 to 144 hours, the floor presented quite a different aspect (see fig. 15, post, p. 285) to that of April 10, the continu- ation ‘0’ being entirely absent, and the elongation of streak ¢ towards the western arm of the trident ¢ being concave towards the western border. On the last occasion, November 19, interval 168 to 156 hours, when ¢ extended OBSERVATIONS OF LUNAR OBJECTS. 265 towards the south-west, the concavity was in the opposite direction (see Lunation November 1869, ante, p. 263). The streak a extended on the 14th of April from Webb’s elbow, and was quite separated from the northern border of Plato. On the 15th it was recorded as very bright, the projecting portion of ¢ being brighter than on the 14th, and nearly joining the western arm of the trident; the continuation ‘“‘o0” was not seen. On the 16th ¢ had disappeared, a being recorded as bright and sharp. On the 17th it was re- corded by Mr. Gledhill. In this lunation “0” was seen from 36 to 84 hours after sunrise. The observations of April 11, 1870, and December 14, 1869, are synchronous as regards interval from sunrise. On December 14 a and “0” formed together the brightest and best-defined streak on the floor. On April 11 “0” was very hazy and ill-defined. These opposite characters under the same solar alti- tudes, as well as those recorded in the previous February lunation, cannot be explained on the hypothesis of changes of illuminating angle, for there were none, but point to some agency operating within the enclosure of Plato. The appearance of the portion of ¢ projecting towards the western arm of the trident on the 14th, its nearly joining the arm on the 15th, and its disappearance on the 16th, combined with the opposite directions of the convexity in November and April, again point to recent or, we may say, present local action. Lunation May 1870, from 24 hours after sunvise to 33 hours before meridian passage. The commencement of the observations during this lunation was charac- terized by the north portion of the floor being brighter than hitherto observed. On May 9 both Mr. Gledhill and Mr. Elger recorded independently this in- creased brightness ; in consequence the streak a could not be traced. The moon’s latitude at midnight was 4° 21'-9 N., Plato at that time being north of its mean position. On May 10 the streak a was seen by Mr. Gledhill. On May 12, interval 108 to 120 hours, or from 12 to 24 hours before the apparition of the projection ¢ in April, this marking, although plainly seen, could not be traced so far to the south as in April, nor was it so sharply de- fined as in that lunation ; indeed all the west portion of the north-west area was hazy as on April 11 and 12, and also on June 10. While this haziness characterized the western part of the floor, the area east of spot No. 16 was free from it; the streak a, as seen Ly Mr. Elger, was very bright and well defined. Is not this indicative of the haziness being due to local lunar action, and of the restriction of such action to a very small area of the sur- face, also of the inefficiency of change in the illuminating angle to explain it? On May 13 the streak a was recorded as bright and well defined, and very bright at the locality of spot No. 19. Lunation June 1870, from 105 to 69 howrs before meridian passage. Two observations only were obtained during this lunation; the first on June 9, 72 to 84 hours after sunrise, when streak a (query its continuation **9”’) had the same nebulous appearance which it exhibited on May 10; the second on June 10, 96 to 108 hours after sunrise, when the eastern portion a was bright and well defined, the western portion “o” hazy, partaking of the general haziness of the north-west portion of the floor. These observa- tions are in striking contrast with those of February (see ante, p. 264), in which neither the haziness nor the continuation “0” were observed. The 266 REPort—1872, brightness on the north-west portion ef the floor appears to have declined since May 9, LIunation July 1870, from 117 hours before to 81 hours after meridian passage. Three observations were obtained in this lunation,—on July 8, 60 to 72 hours after sunrise, when streak a was seen as a bright object; on July 14 and 16, from 156 to 96 hours before sunset, a condensed brightness in the central part of streak a being witnessed, Lunation August 1870, from 9 hours before to 141 hours after meridian passage. Three observations are the only ones recorded, the first on August 11 near meridian. In a drawing by Mr. Elger streak a is shown as very narrow, and quite separated from the north border, the west end crossed by the projection ¢ from Webb’s elbow; “o” was not seen. On the 13th the streak was seen by Mr. Gledhill, a dark tint of floor being recorded by Mr. Pratt. On the 17th the streak was recorded by Mr. Gledhill as the brightest amongst the faint streaks observed. Innation October 1870, from 81 hours before to meridian passage, Two observations only were obtained,—the first on October 6, interval 96 to 108 hours, when streak ¢ was seen quite detached from the border, and figured as narrow by Mr. Elger; the second on October 9, seen near meri- dian, when it (a) was shown as narrow by Mr. Elger, quite separated from the north border, the west end crossed by Webb’s elbow and ¢; these toge- ther form a curved streak, concave towards the west border (see ante, pp. 263- 265), the continuation “o” being entirely absent. Lunation January 1871, from 168 to 132 hours before sunset. In the first of two observations in this lunation, made on January 7, the north-west part of the floor is recorded as being in the same state as in August 1869 (see post, p. 269); in the second, on January 8, Mr. Gledhill recorded the streak a as sharply defined, bright, narrow, and straight. LInunation March 1871, from interval 72 to 84 howrs to interval 96 to 108 hours after sunrise. On the second interval, 72 to 84 hours, the streak a was seen extending from spot No, 19 to spots Nos. 20 and 21; it is described as having been very distinct, On the third interval, 96 to 108 hours, it was observed by Mz. Pratt as the fourth in order of brightness, the sector « and (3 being brighter. Erratum.—Fig. 9, p. 263, dele connexion between streaks ¢ and e; not in original. In the Report Brit. Assoc, 1871, p. 66, the position of streak a is given as determined by three sets of measures by Mr. Gledhill of the two ends of the streak on September 13 and December 9, 1870, and May 1, 1871. The streak is shown in fig. 4 of that Report as long and narrow. The numerous observations of the floor, including those of streak a, show that not only is the north-west part of the floor variable as regards its tint (light or dark), but that the positions of the streaks are also variable ; and this variation is confirmed by the measures, which differ in yalue just as the recorded posi- OBSERVATIONS OF LUNAR OBJECTS. 267 tions differ among themselves. The point of intersection of the measured streaks is in or near the locality of spot No. 19, at which a brightness has been observed. If the bright streaks are due to ejecta (see ante, p. 249), their varying positions may not be difficult of explanation. On September 13, 1870, the measures which determined the position of streak a were as follows :— : For W. end on border parallel to longest diameter 15:3=°319. Ae ANE, # Fr, transverse ,, 10:°2=:213. ee ch ” longest i s0io=" 120. ees rf “ transyerse ,, 13°1=:273. On December 9 they were as follows :— For W. end on border parallel to longest diameter 16-1=-371. Va SEEN < ” > transverse ,, 45= "104. » L Fi a longest jf. eae Oole ae or i transverse ,, 14:7=°339. These measures are more in accordance with two separate streaks, or there may have been four streams of ejecta. As illustrative of the probable permanency of the streaks, at least for some time, I quote the following from observations not included in the period embraced by the discussion :— 1871, October 22; interval 12 to 24 hours (?).—Mr. Elger noticed the north-west portion of the floor as equally light; and on November 27 he recorded the sector, Pratt’s streak p and y, as unusually easy; a diagram is given of a, Webb’s elbow, and a portion of ¢, agreeing with fig. 14, p. 284. 1871, December 22, and following days.—Mr. Pratt noticed the haziness over the north-west portion of the floor so frequently observed in April, May, and June 1870. In the following pages the observations of streak a are arranged, first chronologically, and second in the order of intervals from sunrise to sunset. It is presumed that these arrangements, combined with the foregoing remarks, will contribute to give a completeness to the history of a single feature closely observed during the greater portion of a period of two years. History or STREAK &, CHRONOLOGICALLY ARRANGED. Period of the reoorded appearance of a, 1869, Sept. 20, to 1871, March 3, The entire absence of this streak from the floor of Plato during the period of Mr. Pratt’s observations in August 1869 is noteworthy. 1869. > s Sept.20, 168 to mer. The first record by Mr. Elger’s drawing with the continu- ation “0.” » 25, 72, 60, Observations by Mr. Gledhill of the curvilinear streak from spot No. 18 to the sector, also of ‘‘ 0,” » 27, 24 ,, 12. es notseen, ¢ described asa broad band of brightness. Width 3 from spot No. 1 to rim. Oct. 17,108 ,, 120, Well seen; covers spots 13, 19, and 16; alignment, if pro- duced, would cut N. border of B. & M.’s A. West “0.” » 19,156 ,, 168. Shown by Mr, Gledhill as a long narrow streak. Mr. Pratt mentions a portion of the floor near the mountain “m” on the north of the streak as very dark, » 21,156 ,, 144. Brighter than on the 19th. » 25, 6O,, 48. Dark space between the streak and border, » 26, 86 ,, 24. Seen by Gledhill. » 27, 12,, 0. Seen by Gledhill, 268 1869. + Noy. 14, 60 to 72. » 19, 168 Dec. 12, 24 » 18, 48 » 14, 72 » 15, 96 » 17, 144 » 19,168 » 20, 144 Hie PAM mises; OO » 24, 48 1870 Jan. 11, 36 » 12, 60 y 14, 108 » 15, 182 Feb. 9, 24 ” 11, é 2 pela; 06 Mar. 17, mer. », 19, 182 4) 28 186 -Aprill0, 36 5, dd, 72 » 14, 182 » 16, 168 h » 156. yy Mer. REPORT—1 872, Seen by Gledhill east of spot No. 16; “o” absent. Continued in streak “0,” with ¢ reaching nearly to 6, con- vex to border. Contrast this with later observations, in which it was seen concave to the border; a change is manifest by the contemporaneity of ¢ and “0.” (See re- marks under Sept. 25, p. 295.) Brightness of N.W. area. Seen with difficulty ; N.W. part of floor brightest. Difficult to separate from the bright N. and N.W. part of floor. Continued in “0,” the two forming the brightest and best- defined streak on the floor. The brightness of the N.W. area appears to have subsided. Continued in “o0;” fairly bright. Very bright, extending from Webb’s elbow, which is con- tinued in ec. This phase was more fully developed on April 14, 1870: Mr. Elger’s observation. Recorded as bright. Recorded as bright, and extending from Webb’s elbow. The continuation ‘‘o” appears to have been lost after the 15th. Recorded as the brightest. Recorded as the brightest. Brighter than any other streak. Well seen ; its brightness blends with bright N.W. floor. Continued in “0.” Continued in ‘‘ 0.” Continued in “0,” and extending from Webb’s elbow ; quite separated from border. Bright. Seen as a sharp narrow bright streak from the tip of the most northern shadow to the N.E. border, nearly parallel with a line through spots 1 and 4. From Mr. Gledhill’s measures combined the streak forms an acute angle with the longest diameter through spots Nos. 1 and 4 (see ante, p. 267). Well seen by Mx. Gledhill. Very broad and bright. The continuation “0” was not observed in February or March ; in January it was seen from 60 to 144 hours after sunrise, also in Sept., Oct., Nov., and December. Recorded with sector by Mr. Gledhill as the brightest on the floor and easy. Very bright, with the sector the brightest on the floor. Diffuse and extending up to the N. border; easily but not well seen. Continued in “o;” ill-defined, especially at the N.W. Not seen by Mr. Gledhill as a distinct sharp streak. See Elger's drawing of this date (p. 275.). “09” very hazy and ill-defined. Extending from Webb's elbow, quite separated from the border, the streak ¢ projected towards the south. See diagram by Mr. Elger (p. 285), in which the N.W. part of the floor presents a different aspect to that which it did on the 10th, four days earlier, “0” being entirely absent, and ¢c with e exhibiting a concavity towards the border. Very bright, projecting portion of ¢ brighter than on the 14th, and nearly joining the western arm of the trident: the continuation “o” not seen. 1870; 55» April 16, 163 » 17, 144 May 9, 24 bt, 48 » 12, 103 Pe 18) 199 June 9, 72 » 10, 93 July 8, 60 » 14, 156 LG, 108 Aug. 11, 163 my 1S, 144 17, 48 Oct. 6, 96 ie) 9, 168 1871. Jan. 7, 168 ap 18, 144. Mar. 2, 72 ” 3, 96 a att OBSERVATIONS OF LUNAR OBJECTS. 269 Bright and sharp; projection ¢ has disappeared. Recorded by Gledhill; query “0.” In this April Iunation “0” was seen from 36 to 84 hours, after which c was seen nearly joining e until meri- dian, after which it disappeared. Could not be traced, northern part of floor equally bright as seen by Messrs. Elger and Gledhill. Moon’s latitude 4° 219 N. Seen by Mr. Gledhill. East of No. 16 very bright and well defined, as seen by Mr. Elger. It was seen by Mr. Gledhill east of No. 16, “0” being absent on Noy. 14, 1869, interval 60 to 72 hours. On May 12 the projection ¢, although plainly seen, could not be traced so far to the south as in April, nor was it so sharply defined as in that lunation; indeed all the west portion of the N.W. area was hazy as on April 11 and 12, and also on June 10. This haziness on the N.W. part of the floor while E. of spot No. 16 was well defined is very noteworthy, as indicative of the haziness being dué to local lunar action, and restricts such action to a very small area of the sur- face. Bright and well defined; very bright at the locality of spot No. 19. The streak « (query its continuation “o”) had the same nebulous appearance which it exhibited on May 10. The brightness on the N.W. part of the floor appears to have declined since the early part of the May lunation. The east portion (a) bright and well defined, the west por- tion hazy; it appeared to partake of the general haziness of the N.W. quarter of the floor. These observations are in striking contrast with those of February, in which neither the haziness nor the con- tinuation “0” were observed. Seen as a bright object. Condensed brightness in the middle. Condensed central portion. Shown as very narrow by Mr. Elger, and quite separated from the north border, the west end crossed by e and 7; no ‘0,’ Seen by Mr. Gledhill; dark tint of floor recorded by Pratt. Recorded by Gledhill as the brightest amongst the faint streaks observed. Quite detached from the border, and figured as narrow by Mr. Elger; no “0,” Shown as narrow by Mr. Elger, and quite separated from the north border ; the west end crossed by ¢ and ec, which together form a curved streak concave towards the west border, the continuation “o” being entirely absent. No mention of a; the N.W. part of the floor in the same state as in August 1869. (See figs. 4& 5, p. 252, and figs, 6&7, p. 254.) Recorded by Gledhill as sharply defined, bright, narrow, and straight. Extending from spots No. 19 to Nos. 20 and 21; very di- stinct. The fourth streak in order of brightness as observed by Mr, Pratt, the sector « and 6 being brighter. 24 to 36,1869, Dec. 12. 1870, Feb. 9. » May 9. 36 ,, 48,1870, Jan. 11. » April 10. €0, 1869, Dec. 13. 1870, May 10. 72, 1869, Nov. 14. 1870, Jan., 12. yerdinikyeaek 84,1869, Dec. 14. App ciel dg lil » Apnlll. » June 9, 1871, Mar. 2, BA , es 96 ” 108, 18€9, Dec. 15. 1870, Feb. 12. » June 10. Oct uae. 1871, Mar. 3. 108 ,, 1870, Jan. 14. » May 12: 32 re 120 ,, 132 ,, 144, 1870, Jan. 15. » April 14. 5, May 18. 144 ,, 156,189, Dee. 17, 120, 1869, Oct. 17, REPORT—1872. Arrangement in order of Intervals. Seen with difficulty, N.W. part of floor brightest. Seen as a sharp, narrow, bright streak from the tip of the most northern shadow to the N.E. border, we parallel with a line through spots Nos. 1 and 4, Could not be traced; the northern equally bright as seen by Messrs. Elger and Gled- hill, _Moon’s latitude at midnight 4° 219 N, Well seen, its brightness blending with the bright N.W. floor. Continued in “0;” ill-defined, especially at the N. W. Not seen by Mr. Gledhill as a distinct sharp streak, See Mr. Elger’s drawing of this date, fig. 12, p. 275. Difficult to separate from the bright N. and N.W. part of floor. Seen by Mr. Gledhill. Seen by Mr. Gledhill east of spot No. 16; “o” absent, Continued in “0.” Seen as a bright object by Mr. Gledhill. Continued in “o,” the two forming the brightest and best-defined streak on the floor. Well seen by Mr. Gledhill. “9” very hazy and ill-defined. The streak a (query its continuation “o”) had the same nebulosity which it exhibited on May 10. Very distinct, extending from spot No. 19 to Nos, 20 and 21; “o” absent. No observation. Continued in “0,” fairly bright. Very broad and bright. The east portion a bright and well defined, the west portion “o” hazy; it appeared to partake of the general haziness of the Nw. quarter of the floor, (See note in chronological arrangement.) Quite detached from the border, and figured as narrow by Mr. Elger; “0” absent. The fourth streak in order of brightness as observed by Mr. Pratt, the sector x and @ being brighter. Well seen by Mx. Gledhill ; it covers spots Nos. 13, 19, and 16; alignment, if produced, would cut N. border of B. & M.’s A. Continued in “0,” East of spot No. 16 very bright and well defined as seen by Mr. Elger ; the projection c, although plainly seen, could not be traced so far to the south as be- fore, nor was it so sharply defined as before ; indeed all the west portion of the N.W. area was hazy, as in April and June. No observation. Continued in “0,” and extending from Webb’s elkow; quite separated from the border. Extending from Webb’s elbow, and quite separated from the border, the streak ¢ projecting towards the south. (See note in chronological arrangement.) Bright and well defined; very bright at the locality of spot No. 19. Very bright, extending from Webb’s elbow, which is continued in e art of the floor een h h OBSERVATIONS OF LUNAR OBJECTS. 156 to 168, 1869, Oct. 19. 168) 5, mer., mer. ,, 1€8 ,, 120 ,, 108, 1869, Dec. 21. 108 ,, 96,1870, July 16. 96 ,, 84,1869, Dec. 22. SBE 72 ,, 60, 1869, Sept. 25. iy 45, 5, Oct. 25. 48 ,, » 9 Dec. 24, 1870, Aug. 17. 86 ,, 24,1869, Oct. 26. 1870, Mar. 23, 24 ,, 12,1869, Sept. 27. mee, 4, 3, Ott. +27, 168, 156, 144, 182, » Sept. 20, 1870, April 15. py dines Mule pats > O. op) alll Ne 1869, Noy. 19. » Dec. 19. 1870, April 16. 1871, Jan. 7. 1869, Oct. 21. 1870, July 14. 1869, Dec. 20. 1870, April 17. ». Auge 1871, Jan. 8. y, 120, 1870, Mar. 271 Shown by Mr. Gledhill as a long narrow streak; Mr. Pratt mentions a portion of the floor near the moun- tain “m” on the north of the streak as very dark. Continued in “0.” (See fig. 8, p. 263.) Very bright, the projecting portion of ¢ brighter than on the 14th (interval 132 to 144 hours), and nearly joining the western arm of the trident; the conti- nuation “o” not seen. Shown as very narrow by Mr. Elger (see fig. 18, p. 289), and quite separated from the border, the west end crossed by c and 7; no “0,” Shown as narrow by Mr. Elger (see fig. 19, p. 289), and quite separated from the north border, the west end crossed by? and ¢, which together forma curved streak concave towards the west border, the continuation “9” being entirely absent. These observations (interval 168 hours to meri- dian passage) are quite sufficient to show that the change that supervened between the 20th of Sep- tember, 1869, and the 15th of April, 1870, is in- dependent of illuminating angle and its variations, the new disposition seen in April of the streaks on the N.W. part of the floor continuing to October 9, 1870, at this period of the luni-solar day. Recorded by Mr. Gledhill as easy, and with the sector as the brightest on the floor. Continued in streak “0,” with c reaching nearly to 8; convex to west border. This is greatly in contrast with the observations of October-9, 1870 (see in- terval 168 hours to meridian), Recorded as bright. Bright and sharp; projection ¢ has disappeared. No mention of a; the N.W. part of the floor in the same state as in August 1869 (see figs. 5, 6, and 7). Brighter than on the 19th of October, 1869 (see in- terval 156 to 168 hours). Condensed brightness in the middle, Recorded as bright, and extending from Webb’s elbow. Recorded by Gledhill; query “0,” (See note in the chronological arrangement. ) Seen by Gledhill ; a dark tint of floor recorded by Pratt. Recorded by Gledhill as sharply detined, bright, nar- row, and straight. Very bright, with the sector the brightest on the floor, Recorded as the brightest. Condensed central portion. Recorded as brightest. No observation. Mr. Gledhill observed ‘0,’ also the curvilinear streak from spot No. 13 to the sector. Dark space between the streak and border. Brighter than any other streak. Recorded by Gledhill as the brightest amongst the faint streaks observed, Seen by Gledhill. Diffuse and extending up to the north border, easily but not well seen. anot seen, ¢ described as a broad band of brightness, width about one third the distance from spot No, 1 to the border. Seen by Mr. Gledhill, 272 REPORT—1872. IV. Oxzsrervers’ Notts. Interval 12 to 24 hours. State of floor at sunrise (fig. 10).—For observations at sunrise, see Report 1871, pp.67 to 76, also p.96, where the reader will find Mr. Pratt’s observations Fig. 10. State of floor at sunrise, 1870, Noy. 1, 6" to 64 40™, of sunrise. In reference to the dip of the floor to the margin there men- tioned, which is well established, I may remark that on the 20th of Novem- ber, 1871, I noticed the streaks of sunlight at sunrise terminated on the east at some distance from the border, indicating a considerable dip of the floor, if the sunlight were reflected from the true floor. (See Report 1871, p. 68, Jan. 10, 3 hours.) In reference to the streak between spots Nos. 4 and 3, I would observe that the continuous observations of the streaks n and B by Messrs. Gledhill and Elger strongly indicate that they are connected with spots Nos. 4 and 3; the narrow shading between these spots, as shown by Mr. Pratt, is most likely a shallow depression between the streaks if Mr. Pratt’s suggestion of their being spurs be correct (?).—W.R.B. Fig. 10 shows the dip of the floor to the E. border, Tint of floor 9-33. The difficulty experienced on the night of Nov. 20, 1871, in obtaining a good view of sunrise on Plato (if inexplicable on the fact of different apertures having been employed, 74 in. on the 10th of Jan. 1870, and 23 on Nov. 20, 1871) may have been produced by an absorptive medium within the enclosure of Plato: the appearance mentioned in Report 1871, p. 68, was more intensi- fied than I had previously witnessed, and the western portion of Plato, that OBSERVATIONS OF LUNAR OBJECTS. 273 nearest the western border, was darker than the eastern; and there, where the sun’s rays were more obstructed than further east, the peculiar appearance of something reflecting the stronger light from the brighter border above the surface was not seen. The most expressive description that I can give, after twenty-four hours’ consideration, is, in‘the words of Schroter, “a kind of fer- mentation.” It is certainly very unusual for the clearness of objects near the terminator to be interfered with; but should there have been “ vapours” in motion, catching momentarily the reflected rays and, as the sun rose higher, the direct rays over the mountain-border, such an appearance as I witnessed must have been produced; and the presence of such vapours may occasion the darker tint of the floor, and especially the indistinctness of the boundary of the streaks of sunlight and the edges of the shadows. I never before observed the floor of Plato to be so dark; but I have seen it once only under similar circumstances, except that of aperture. Interval 24 to 36 hours. 1870, May 9.—Mr. Elger’s record is as follows:—‘ Markings not well seen” (but he does not specify them); “ the sector was the brightest.” He also says, “the northern portion of the floor [that which on August 26, 1869, was dark and extended between the streak ¢ and the border] was noted as equally light ; the streak a could not be traced.” On the same evening Mr. Gledhill recorded the floor as light, =0-33, and that streak a was not to be distinguished from the bright floor all along the north border. - He described the streaks as faint and rather diffuse, the sector faint, not sharp at edges, and seemed broader than usual. Libration in latitude S. in August and N. in May would tend to throw streak a apparently nearer the N. border in May; but Mr. Gledhill could not distinguish it from the general brightness, Chronological progression of increase of brightness on the N.W. part of the : floor of Plato. On referring to Mr. Elger’s drawings of January 12, 1870, interval 60.to 72 hours, and January 14, 1870, interval 108 to 120 hours, I find the N.W. part of the floor extending from Webb’s elbow to very nearly the position of the west arm of the trident equally light; indeed presenting on the 12th a similar contour to Mr. Elger’s sketch of May 10, 1870, interval 60 to 72 hours, the difference being that on the 12th of January, 1870, the streak a was distinctly separated from the border. The streak a was first recorded by Mr. Elger on September 20, 1869, interval 168 hours to meridian passage, and his diagram of that date is strikingly in contrast with those of Jan. 12 and 14, and May 9 and 10 (see fig. 8, p. 263, and fig. 11, p. 274). On September 25, 1869, interval 72 to 60 hours, we have a diagram (see fig, 9, ante, p. 263) of Mr. Gledhill’s in which the N.W. part of the floor is figured as nearly similar to Mr. Elger’s of the 20th, the streak including the three spots Nos. 13, 19, and 16. On October 17, 1869, interval 108 to 120 hours, Mr, Gledhill again saw the streak, and described it as a “‘ well seen streak which covers 13, 19, and 16;” he aligned it thus: “the streak produced E.N.E, would cut the north border of B. & M.’s crater A outside Plato.”’ On October 25, 1869, interval 60 to 48 hours, Mr. Gledhill gives a diagram in which a and “9” occur with a dark space between the streak and the border. On November 19, 1869, interval 168 to 156 hours, Mr. Gledhill saw the streak a with its continuation “0,” Webb’s elbow, and the streak c, “o” and ¢ diverging from the western side of Webb’s elbow. The earliest instance of an increase of light on the N.W. part of the floor, and of the observation of Webb’s elbow during 1872. U 274 REPORT—1872. the present series of observations, occurred on Nov. 15, 1869, interval 84 to 96 hours. See also December 13, 1869, interval 48 to 60 hours, p. 278, when Fig. 11. _— Plato, January 12, 1870.—T. G. E. Elger. Mr. Gledhill recorded the N. and N.W. parts of the floor as brightest. On De- cember 14, 1869, interval 72 to 84 hours, Mr. Elger sketched a and “ 0,” with Webb’s elbow, the west side of which merged into the streak “0,” The streak ¢ seen by Mr. Gledhill and the spots Nos. 13,19, and 16 were not seen. Mr. Gledhill mentioned the bright floor connecting a and 6 without a distinct streak. The next day, Dec. 15, interval 96 to 108 hours, the elbow is not separately given ; the two sketches (see figs. 11 and 13) very much resemble those of January 12 and 14, 1870. The state of the N.W. part of the floor was nearly similar during the two lunations, the greatest amount of light being observ- able at the earlier epoch in both cases. Mr. Gledhill noticed the N.W. part of the floor bright on January 11, interval 36 to 48 hours. In Mr. Elger’s diagram of Sept. 20, 1869 (ante, p. 263), he gives three light markings—the sector 6, the middle arm of the trident e, and a straight marking on the N.W., replacing the curved streak ¢ of Pratt of August 1869. The western branch of this streak appears to be connected with spot No. 19. To distinguish it from h, which crosses it, it is designated “o;” the eastern portion which joins the N. border is a. On December 20, 1869, interval 144 to 132 hours, the floor was approaching its normal state. 1870, March 11.—Mr. Gledhill recorded the floor as ‘‘medium, =0-50, like the tint of the Mare Frigoris.” 1870, February 9, 4.45.—Mr. Gledhill described the floor east of a line through spots Nos. 1 and 3, produced both ways, as “dusky.” At 7 hours Mr. Gledhill writes, “ E. part of floor still dusky as far as the east edge of sector, and a line along this edge produced to the north border.” Streaks coming into sunlight.—1870, February 9, 5.40. Sector seen faint, but easy. Streak a seen as a sharp, narrow, bright streak, running from the tip of the most northern shadow across to the N.E. border; it is nearly ; OBSERVATIONS OF LUNAR OBJECTS, 275 parallel with a line through spots Nos. 1 and 4, but falls a little at the east end. Streak y seen extending from alittle 8. of the middle of II E ¥2, faint: 6 hours. Streak 3 seen running from spot No. 3 to the N. border. 1869, December 12.—Mr. Elger says, “I could make out a portion of the sector, but it was exceedingly ill-defined; the remaining part of the floor appeared to be of a uniform tint.” Mr. Gledhill recorded the floor as light, =0°33, and the sector faint, nearly as dark as the floor. The streak a seen with difficulty ; the N.W. portion of the floor brightest. The shadows of the west border had edges on the east very well defined, as if a narrow strip of light fringed them without nebulosity. [This last remark appears to be in- compatible with the idea of both spots and streaks being difficult of observa- tion on account of the bad state of the earth’s atmosphere ; for the same observer, with the same instrument at the same time, describes the sector and a as difficult, while the shadows are so well defined as to exhibit dif- fraction fringes. Should the paucity of spots and streaks on this occasion not have been dependent on our atmosphere, then we have a different state of things to that which conduces to the apparition of spots when streaks are faint, and vice versd. | 1870, October 3.—Mr. Elger recorded the sector as complete and faint, but in strong contrast with the dark floor; he remarks that it is unusual for him to see the sector at so early a period of illumination. Mr. Gledhill recorded the sector, with streaks a, 3, y, 6, «, and Z, as seen. Summary.—Sun’s altitude 7° 48'-1 to 11° 38-2; tint of floor 0-39. Streaks generally visible—sector, y, 3, a, and arms of trident; they are mostly faint, but a was seen as a narrow bright streak on February 9, 1870. Interval 36 to 48 hours. 1870, April 10.—In Mr. Elger’s diagram of this date the connexion is unmistakable of the sector 6 with spot No. 4, also the N.E. end of the streak » with the same spot. The connexion of streaks Z, e, and 3 with Fig. 12. Plato, April 10, 1870.—T. G. E. Elger. spots Nos. 1, 14, and 3 respectively is also apparent. In his remarks Mr. Elger says, “ the east arm of the trident was traced through spot No. 5 to spot No. 1; it usually terminates near 5.” He also says, “ although faint, U 276 REPORT—1872. the markings were easily traced; those on the east side of the floor, y, », and 3, were decidedly the brightest ; » was represented by a bright fan-shaped marking close under the east wall.” [This is clearly the bright object de- seribed by Mr. Gledhill under date March 23, 1870, 36 to 24 hours (see post, p. 296), before sunset on Plato; and it is evident that it retained the qua- lity, whatever it may have been, which contributed to its bright appearance during the intervening night. This quality appears to have affected the whole of the northern part of the floor; for we find, 36 to 24 hours before the previous sunset, the streak a described by Mr. Gledhill as “ diffuse and extending up to the north border, and the following forenoon it could not be seen as a distinct sharp streak.”—-W. R. B.] Mr. Elger described the streaks a and “0” (seen as one) as ill-defined, especially the N.W. portion of it. The eastern and middle arms of the trident were the only streaks seen on the 8.W. Mr. Gledhill, same evening, gives on a diagram the positions of the sector and streaks more or less similar to those given by Mr. Elger, and they both agree in placing spot No. 5 on the east edge of ¢. Mr. Gledhill describes all streaks as faint, and 6 and @ (query e), on tinted plate in ‘Student,’ p. 161, as meeting at a point two thirds the distance from the west border to spot No.1. The east edge of sector is described as cutting the 8.E. border a little west of the middle of the straight part of the 8.E. border, and the west edge of sector cuts the south border nearly in the middle. Mr. Gledhill says, “ the brightest part of the floor is the north and north-west, near the north border.” awas not seen as a distinct sharp streak. “Tf,” says Mr. Gledhill, “the east edge of the sector be produced to the north border, the darkest part of the floor lies to the east of this line. Is not this the line of fault marked in your key-plan (Report Brit. Assoc. 1861, p- 183) some years ago? and is not this the portion seen brightest near sunset at Plato on March 24,1870?” Mr. Gledhill noticed that the most southern-pointed shadow (a blunt cone) from the west border was situated on and in the line of the streak 6 (query e). He does not mention the bright part of » seen by Mr. Elger, but gives the entire streak from spot No. 4. 1870, July 7.—Mr. Neison recorded the floor as dark, =0°66; he says, ‘«‘ Never saw the floor so dark ; spots very indistinct, not visible continuously.” This is remarkable at so early an epoch, when the floor is generally described as light or bright. It is also remarkable that the spots should have been indistinct with so dark a floor. Mr. Elger remarked that the sector could just be traced. 1870, January 11, 5.36.—Mr. Gledhill records the floor as bright, =0-33. Determination of the position of sector.—See Report Brit. Assoc. 1871, pp. 66 & 67, and ante, p. 249. Mr. Gledhill determined the 8.E. extremity of the east edge of sector as cutting the S.E. border nearly in the middle of the straight wall to the south of Il E ¥?, and the south extremity of the west edge as cutting the south border at a point characterized by a line through spots Nos. 3 and 17 pro- duced to the south border, 2. e. spots Nos. 3 and 17 and the south end of the west edge of sector align. [On comparing this alignment with the plan from Mr. Gledhill’s measurements (p. 66, Report 1871), it will be seen that it does not agree with the plan. There is abundance of evidence to show that the boundaries of the markings are variable in position.—W. R. B.] Mr. Gledhill recorded the sector as but little brighter than the floor; in the darker parts streaks a, B, 7, y, 6, e, were well seen. The N.W. part of the floor was bright, and blended with the brightness ofa. 7° 0™. Streak A extends a little towards the 8.W. of spot No. 3; streak » cannot be traced OBSERVATIONS OF LUNAR OBJECTS. 277 clearly up to the border, but it is very bright close to the border. «It seems,” says Mr. Gledhill, “as if it were thrown off by the bright lofty wall close to the north of II E¥*.” [The dip of the floor to the border all round has been well determined. Does not this dip prevent not only the tracing of the streak, but its really extending as far as the border?] The sector passes on to spot No.3, 6 (?) meets e about halfway from the west border to spot No. 1 (see ante, p. 247, fig. 1); they are both well seen, are sharp, and the dark space between them is sharply defined. On the same day Mr. Elger’s re- cord was as follows :—‘ The sector could be traced from spot No. 4, through No. 17, to the southern rim, and from No. 4 to the south of the triangular formation, II EK ¥?, on the eastern rim; but it was very faint and badly de- fined. The streak y was not seen; but I remarked that the N.W. portion of the floor, especially near the border, was much lighter than the remainder. No traces of the trident.” The difference between the observations of Mr. Gledhill and Mr. Elger is mainly attributable to difference of aperture, with a probable difference of atmosphere ; they both agree in the greater luminosity of the N.W. part of the floor inthe neighbourhood of Webb’s elbow. 1869, August 16.—See ante, p. 251. 1870, December 2.—Mr. Elger described the sector as very faint. 1870, November 2.—Mr. Elger recorded “ faint traces of the sector.” Mr. Neison remarked that the streak of light near spot 17 (the sector), was much darker, or rather less bright than usual. Summary.—Sun’s altitude 11° 382 to 15° 233; tint of floor 0-39, esti- mated from curve. Streaks generally visible—sector, arms of trident, and those on the northern and eastern floor, viz. Webb’s elbow, ¢, a, (3, n, and y. This interval.has been characterized by an extension of the sector as far as spot No. 3 on January 11, 1870, and of streak (§ beyond the same spot 3 on the same day. Were these extensions due to activity in group 3? It may be noted that streak a was well seen on the same day. Another inter- esting feature of the interval is-the retention, during the night between sunset in March and sunrise in April, of the quality by certain portions of the floor by which they reflect light more strongly than under ordinary cir- cumstances. The extreme faintness of the sector on November 2 and De- cember 2, 1870, as well as its general faintness, is remarkable. Interval 48 to 60 hours. 1871, March 1.—Mr. Gledhill recorded the floor as light, =0°33; streaks very faint, not well seen. Mr. Elger described them as generally faint, espe- cially those on the southern part of the floor. 1870, May 10.—Mr. Elger speaks of the sector and streak y as very bright and sharply defined, /; much brighter than y. Trident faint, especially the west arm e. ‘The lighter portion of the floor near the N.W. border was faint, especially at the west; it appeared to follow the curvature of the border of Plato. No trace of the elbow. Mr. Gledhill recorded the floor as “near medium” [registered =0-50], and the streaks brighter than last night [the 9th]. Mr. Gledhill mentioned his having seen a, from which it may be in- ferred either that the streak was really brighter than on the 9th (see ante, p- 273), or that the brightness on the northern part of the floor had declined in intensity. Mr. Pratt says: “6 [the sector} and « were of the streaks the most visible. The whole of the western end of the floor which was in light appeared covered by a continuous haze of brightness, the chord of the are running nearly N. and §.; a faint glimmer of was all that was possible.” 278 REPORT—1872. The light portion of the floor Mr. Pratt described as extending from the west border as far as the streak g and Webb’s elbow, as shown on the tinted plate in ‘ Student,’ April 1870, p. 161. 1870, March 12.—Mr. Gledhill records the floor as * light, like the sur- face of the Mare Frigoris, ‘medium.’” I have registered it as 0-42. He says, “all streaks seen except A, which runs west from the spot No. 3.” Of streak 7 he says, ‘‘7 does not reach up to No. 4; it is a brush of light near the inner border just to the N. of II E¥?.” [This certainly does not accord with », but is much nearer the position of Pratt’s 7. There appears to be good evidence that the streaks slightly vary in extent and position.—W. R. B.] 1871, January 1.—Mr. Elger described the markings as “all faint,” but did not specify them, except p, of which he says, “the new marking on the south side of the floor could be traced to the east of spot No. 5 (to about half- way between 5 and 17).” In his sketch December 4, 1870, Mr. Elger places spot No. 5 on the west edge of Z. 1870, August 6.—Mr. Gledhill recorded the floor as medium, =0°50, and the streaks as faint and scarcely distinguishable from the floor. On the same evening Mr. Elger says, “Sector seen, but its borders were very badly defined.” He also described the west portion of the floor as of an even light colour. This observation is greatly in accordance with Mr. Pratt’s of May 10, 1870 (see ante, p. 277); the increase of light in both cases most probably depended upon the same agency. 1869, December 13.—Mr. Gledhill recorded the tint of floor as light, =0-33, the N. and N.W. portions being the brightest. The sector was well seen, extending as far as spot No. 3, with a bright base resting on the border ; a and its vicinity, both to the south and up to the north border, bright and difficult to separate. It [this brightness] extends up to 6 [and consequently includes « and c]; 6 widens as it approaches the border of Plato. [Does Mr. Gledhill mean that the light surface extended from the western arm of the trident on the N.W. and N. as far as spot No.3? If so, the great northern streak would, in consequence of the sector and ¢ being connected by the extension of the sector to spot No. 3, have nearly the same contour as given by Mr. Pratt on August 17, 1869, see ante, fig. 5, p. 252.] e« and Z were well seen. Neither y nor 3 were strong nor broad; » was the faintest streak on the floor. Mr. Gledhill speaks of streak ¢ widening as it approached the border. This widening is by no means an uncommon occurrence; the sector is a familiar example, also the streak » has presented this phenomenon : both the sector and y proceed from spot No. 4, which of all the spots is characterized by the most remarkable appearances. Now this widening is closely in accordance with ejecta spreading from an orifice as it descends a surface slightly inclined. Mr. Elger has shown (Report Brit. Assoc. 1871, p. 71) that the surface between spots Nos. 1 and 4 is depressed. Mr. Gledhill says: ‘‘I have never noticed that portion of the trident east of the spot No. 1; I am looking for it. I always see that portion of the trident in which spot No. 22 is situated as nearly in a line with spot No. 1 and II E¥2.” 1870, October 4.—Mr. Elger saw the sector only; it was in strong contrast with the floor. He also exhibits the light border skirting the west side of the floor. Mr. Gledhill says:—‘ The west portion of the floor is the brightest ; the line of separation runs through a point midway between spot No. 1 and the west border, and both ways to the north and south borders. This space includes Webb's elbow, c, the west end of é¢, and S.W. end of e.’’ Similar observations of this light portion are recorded under May 9 and 10, the OBSERVATIONS OF LUNAR OBJECTS. 279 latter by Mr. Pratt ; also on August 6 by Mr. Elger. These observations are in contrast with those of Mr. Gledhill, 1869, December 13 (see ante, . 278). ‘ et sa. altitude 15° 23'-2 to 19° 2-0; tint of floor 0-41, esti- mated from curve. Streaks generally visible—the sector, arms of trident, and a, 6, y, with yn, not quite so frequent, generally faint ; but on Oct. 13 Mr. Gledhill saw the streaks stronger in the S.W. On May 10, 1870, the streaks were recorded as bright; and on October 3 and 4, 1870, the floor remained in a similar state, viz. dark, with the sector, although faint, strongly contrasted with it. The N.W. part of the floor does not appear to have attracted special attention on December 15, 1869, March 11 and 12, 1870, nor on January 1 and March 1, 1871. Interval 60 to 72 hours. 1870, May 10.—See interval 48 to 60 hours, ante, p. 277. 1870, July 8.—Mr. Gledhill recorded the floor as bright, =0-33. The sector and streaks a, é, and e were seen as bright objects. He gives no record of a bright N.W. floor. 1870, January 12.—Mr. Gledhill writes, “Streaks all seen, but not so bright as last night.” Same evening Mr. Elger writes :—‘‘ Tracing No. I. (see ante, p. 274, fig. 11) is from a drawing made about 7° 25™, which, as far as all the markings are concerned, scarcely differs from No. II. for December 1869. [In the tracing for Dec. 15, 1869, the one referred to (see fig. 18, p- 283), the streak y is absent and the brightness on the floor adjoining the west border.} I noted the sector as the plainest and best defined ; the three branches of the trident could just be traced, but they were very ill-defined ; the fan [y] from No. 4 was plain, and the eastern portion (under the east rim) yery bright as compared with the other markings. The streak y was well seen, though faint; (6 could also be traced, but I was unable to see any signs of spot No. 32” [within or on it]. On the same evening, January 12, Mr. Pratt writes :—< Sector b seen badly without S.E. ray [1], and con- nected as usual with streak ¢ [agreeing in this respect with Mr. Gledhill’s seeings |, which appeared connected with the north border near m [this con- nexion is by Webb’s elbow i]. Trident observed, excepting the junction of its arms; its stem seen. Contour of floor very similar to sketch of 1869, August 26.” [On December 13, 1869, Mr. Gledhill’s seeings were some- what similar (see interval 48 to 60 hours, ante, p. 278). ] 1869, August 17.—See ante, p. 252. 1869, November 14.—Mr. Gledhill recorded the sector as “fairly bright,” ¢ and e as broad and bright, and extending beyond and through spots Nos. 5 and 14; # faint, and a entirely east of spot No. 16, and from it a extends to the east border. Summary.—Sun’s altitude 19° 2'-0 to 22° 31'3; tint of floor 0-45, esti- mated from curve. Streaks generally visible—sector, east and middle arm of trident; the others are not so frequent, but more of them are seen, and they are mostly brighter than in the earlier intervals. 1870, July 7 and 8, there appears to have been an absence of brightness in the N.W. part of the floor. Interval 72 to 84 hours, 1870, April 11.—Mr. Elger recorded that all the markings seen on the 10th inst. were reobserved with the addition of the west arm of the trident (e); “‘0” was very hazy and ill-defined, » well seen. On the same evening Mr. Gledhill recorded the floor as medium, =0°50. The north floor at the 280 REPORT— 1872. foot of the north border was brightest, especially at the N.W.; all streaks rather faint, especially the sector. Mr. Pratt speaks of “cloud” in the N.W. and 8.W., where a ray from Anaxagoras appears to cross the floor, inter- fering with the trident, of which the arm east of spot No. 1 (¢) and the west arm (€) were much obscured. 1871, March 2.—Mr. Elger records the markings as mostly faint. Webb’s elbow and the streak a extending from spot No. 19 to spots 20 and 21 very distinct. The new marking, p (Mr. Pratt’s), west of No. 5, faint but trace- able. 1870, March 13.—Mr. Elger described the markings as faint and ill- defined ; they were the same as seen on January 12, 1870. Mr. Gledhill recorded the floor as ‘‘ medium or light, like Mare Frigoris,” registered =0-42. Webb’s elbow was well seen near the foot of the inner N.W. border. 1870, June 9.—Mr. Elger recorded the markings as faint and difficult to trace. The streak a on the N.W. part of the floor had the same nebulous appearance that it had on May 10. [Mr. Elger does not appear to have noticed a brightness of the N.W. part of the floor equal to that observed on May 9.1] 1870, February 11.—Mr. Elger writes :—“ All the markings shown on tracing No. II. (1870, January 14) were seen, but they were very faint. The three branches of the trident could just be traced.” On the same evening Mr. Gledhill says :—* Streaks a, /3, y, 6, e, ¢ are well seen, as also the sector. I see a faint streak just above the west end of a and parallel with it; this streak, if produced eastwardly, would pass just north of spot No. 3 (see fig. 16, post, p. 286). The streak ) is seen easily, it is the faintest ; streak B extends a little to the west of spot No. 3. There is a strong brush of light from the border just north of II E ¥2, from which a faint streak runs up to spot No.4.” [Is this Mr. Pratt’s 7? its direction agrees, but its locality is rather too far to the north. See interval 48 to 60 hours, 1870, March 12, ante, p. 278.] 1869, December 14.—Mr. Elger recorded a and its continuation “0” as the brightest and best defined on the floor, and he shows Webb’s elbow in con- tact with the N.W. border. Mr. Gledhill mentioned the bright floor con- necting a and 6, but without a distinct streak; he recorded the floor as light, = 0-33, and all the streaks as well seen, 7 the faintest, and the extension of the sector to spot No. 3not easy. Mr. Elger says:—‘ The sector I noted as faint and difficult to trace ; the middle prong of the trident appeared to be the brightest on the S.W. side of the floor; it could be traced as far as spot No. 14.” Mr. Pratt noticed the trident shaded off round spot No. 1, the sector nearly divided between spots Nos, 3 and 4, and y in contact with the sector. Summary.—Sun’s altitude 22° 31':3 to 25° 49-5 ; tint of floor 0-49, esti- mated from curve. Streaks generally visible—sector, trident, and the N.E. streaks a, 3, y, and y mostly faint; \ and » were observed on February 11, 1870; and a, with its continuation “ 0,” was recorded as the brightest and best defined on the floor on December 14,1869. Interval 84 to 96 hours. 1870, March 13.—See interval 72 to 84 hours, see above. 1870, December 4.—Mr. Elger writes:—‘The marking connecting the middle and east arms of the trident, which was, I believe, first seen by Mr. Pratt last spring, I found a very easy object, fully as bright as the brightest portions of the trident; it follows the curvature of the south border, and, OBSERVATIONS OF LUNAR OBJECTS. 281 crossing the east arm of the trident, terminates about halfway between the latter and the west limit of the sector. During the May and June lunations I had faint glimpses of it, but it was then a more difficult object than it is now.” 1870, September 6.—Mr. Gledhill recorded the floor as dark, =0-66. Streaks very bright and well seen. 1869, November 15.—Mr. Pratt has the following remarks on the light- streaks :_—‘‘ The trident and sector were both reobserved complete, with the exception of the shading off round spot No.1. (See interval 72 to 84 hours, ante, p. 280.) A considerable addition was also well observed. 1°. The sector appeared widened out between spots Nos 3 and 4. 2°. The N.E. streak was traced of the form sketched, and in contact with the border. [This appears to be the earliest instance of the greater reflective power of the northern part of the floor, which is independent of libration, inasmuch as both on August 26, when the streak was quite free from the border, and on this day, when in contact with it, the moon had south latitude. It is also independent of illuminating angle, as it was most extensive and brightest at an interval of 24 to 36 hours (see that interval, May 9).] 3°. A tongue of light jutting out from the border on the north of B. and M.’s Z, 7. e. the high rock at the east of Plato. [This is the streak », first recorded by Mr. Gledhill on Oc- tober 19, 1869.] 4°. The sector [or streak] on the north of spot No. 3 spread out as far as the border, and enclosing spots No. 20 and 21. 5°. The streak ¢ made another contact with the border near spot No. 16 [this contact is Webb’s elbow]. The streak was connected with the N.W. arm (e) of the trident, being continued beyond its usual termination near spot No. 13, and could be traced to about halfway towards the middle arm (e), beyond which it was quite invisible.” [On the next luni-solar day, December 13, 1869, interval 48 to 60 hours, the same general distribution of the streaks, with the extension of the lighter surface to the north border, was seen by Mr. Gledhill (see ante, p. 278).] In Mr. Gledhill’s observations of November 15, he does not mention the streaks separately, but gives on the diagram the sector b diverging from spot No. 4. He does not indicate the widening out between spots Nos. 3 and 4, as seen by Mr. Pratt. He gives y and # both up to the border, also the streaks a and c, but does not give the continuation into the trident, which it appears he did not observe except the streak 6. 1869, October 16.—Mr. Pratt recorded the junction of the trident as difficult, especially so just west of spot No. 1; the sector and much the brightest. Summary.—Sun’s altitude 25° 49'-5 to 28° 54°3; tint of floor 0°52, estimated from curve. Streaks generally visible—the sector and trident, the N.E. streaks less frequent ; trident seen complete with stem on October 16 and November 15 by Mr. Pratt. Interval 96 to 108 hours. 1870, April 12.—Mr. Gledhill recorded the floor as dark, =0°66; he de- scribed the streaks as all brighter than on the 11th. Mr. Pratt on the same evening recorded the sector as very easy; also J, x, ¢, a, and 3; ny was seen, not ag a streak, but a tongue of light running from the border towards spot No. 4. The streak n (very rarely seen) was observed extending from spot No. 1 to streak x; ¢ and e, the eastern and the middle arms of the trident, were difficult; the western arm of the trident was very faint. The whole area bounded by spots Nos. 14, 1, and 16 with the western border very hazy. Crater G on the exterior N.W. slope well defined at times. 282 REPORT—1872. 1871, March 3.—Mr. Gledhill recorded the floor as dark, =0-66 ; the streaks bright. Mr. Pratt recorded the floor as medium,=0-50. This evening he witnessed an unusual display of streaks, as many as fifteen, which he arranged in order of brightness thus :—the sector, the curved streak « near the north border, the streak 3 from the triple group of spots Nos. 3,30, and 31, the streak a from spot No. 19 to the N.E. border, the middle arm of the trident e, the N.W. curved streak c, Webb’s elbow 7, the eastern arm of the trident Z, the N. bifurcation of the western arm 6 and the southern bifurcation 6, the narrow streak from 8.W. to N.E., , very rarely seen, the short arm / of the sector towards the S.E. also very rarely seen, the streak y from spot No. 6, the streak » from spot No. 4, and the new streak p from spot No. 5 to spot No. 17 (this, Mr. Pratt remarked, was seen easily joining the eastern arm of the trident and the sector from a point opposite to No. 5 to a point closely south of No. 17; it was narrowed about the middle). The streaks #, a, and / were far brighter than in their normal state. 1870, May 12.—Mr. Gledhill recorded the floor as dark, =0-66, and the streaks bright. He does not mention the sector; but from his remark that all were seen, and Mr. Elger regarding it as “very bright,” I have in- serted it. 1870, March 14.—Mr. Elger’s record is as follows :—‘‘ The markings were not well seen; the eastern arm of the trident was the brightest, and could be traced from the south rim of Plato to spot No. 1, passing to the west of spot No. 5. The streak y was very plain; the rest of the markings were very faint and difficult to make out.” Mr. Elger further says :—“ In spite of the haziness of the sky, the markings and minute details of the northern part of the Mare Imbrium were seen with unusual distinctness.” [This is another impcrtant testimony to the unequal visibility of objects, and would indicate that the indistinctness of the markings on Plato was dependent upon some agency more immediately connected with the moon itself.| About an hour earlier on the same evening Mr. Pratt observed Plato, and recorded the mark- ings as rather easily visible. He observed all he had seen before, which were of almost the identical forms of 1869, November 15 (see interval 84 to 96 hours, ante, p. 281). He also recorded two bright streaks from Anawagoras, which crossed the N.W. border, the streak c, and the N.W. arm of the trident, and somewhat confused at first sight the light-markings on the floor (see ante, p. 280). 1870, June 10.—Mr. Elger recorded the sector and the streak y as the brightest markings ; 7 and ( were faint, especially »; 6, though faint, could be traced up to spot No. 3. The eastern portion of a was bright and well defined ; the west portion had a hazy appearance, as, indeed, had the whole of the N.W. portion of the floor. Mr. Gledhill described the streaks and spots as bright, and seen as on June 9; he recorded the floor as dark, =0-66. 1870, February 12.—Mr. Gledhill recorded the floor as “ medium, but nearer dark.” Ihave registered it at 0°55. Streaks all seen, except the two faint ones \ and»; e, the middle arm of the trident, brighter than either g ord; a very broad and bright; 3 and y well seen; » not distinct near spot No. 4, but bright near the border of Plato. 1870, August 8.—Mr. Gledhill recorded the floor as rather dark, =0-70. Streaks not very bright, but well seen. 1869, December 15.—Mr. Elger writes:—‘‘ The markings on the floor were much more distinct than on the 14th. The prongs of the trident (Z, e, é), the sector (6), a fan of light extending from spot No. 4 to the east rim (yn), and the brush (3), on which spot No. 32 is situated, are shown on fig. 13, OBSERVATIONS OF LUNAR OBJECTS. 283 Mr. Elger’s diagram of this date fully confirms the observations by Mr. Gled- hill of the streaks 6 and yn, and their parallelism with a in September and Plato, Dec. 15, 1869.—T. G. E. Elger. October. I believe this to be Mr. Elger’s first observation of these streaks. Taking into consideration the difference of apertures, were they first within reach of the smaller aperture of 4 inches on this day (December 15)? If so, did they become brighter during the interval that elapsed since Mr. Gledhill first saw them? At the close of the October (1869) observations, Mr. Gledhill furnished the following information :—“ Parallel streaks on N.E. floor. Ihave gone over all my observations, and find that y (see fig. 9, ante, p. 263) has always been seen except at sunrise and sunset. 3 appears in my observations for the first time September 25, 1869, about 11 hours. At this time the light sector passed beyond spot No. 4, and had its apex about spot No. 3. It was also seen at this point again on October 21 at 12 hours.” [Was there any connexion be- tween the sector extending as far as spot No. 3 and the streak 8 emanating from the same spot, as if the spot or group had been in eruption? The very short extension of the streak /3 seen once or twice by Mr. Gledhill beyond spot No. 3 towards the 8. W. is curious, as ifit were an outflow in that direction which could not proceed in consequence of the rising of the ground.| Mr. Gledhill further remarks :—“ I saw 6 a few hours before sunset on Plato on the 27th of September, 1869, and also the sector and some other streaks. The streak y was first seen by me about 11 hours on October the 19th, 1869. It comes from that fine summit on the crater-wall (the rock Z of B. and M.) which casts the long shadow on the plain at sunset. The streak 6 I think comes from a portion of the inner slope, which is often highly illuminated ; B and y are nearly always seen now. [Mr. Gledhill appears to regard these streaks as emanating from the wall. Is it not more likely that » emanates from spot No. 4, and ZB from spot No. 3?—W. R. B.] On the evening of De- cember 15,1869, Mr. Gledhill recorded the streak 3 as fairly bright, and as faint near spot No. 4, with a broad brighter base, which is, as mentioned elsewhere, quite in accordance with phenomena of eruption from spot No. 4. Ihave made the following remarks on the form containing Mr. Gledhill’s observations :—‘ 7, which, if I remember rightly, Mr. Gledhill first saw as a narrow streak, to-night is described as broad, with bright base, faint near spot No.4. Mr. Elger on the same evening described a ‘fan’ of light from 284 REPORT—1872. spot No. 4. He has not mentioned it before. Mr. Elger gives 8 with the spot No. 32, discovered by him this evening.” Mr. Gledhill’s record of the remaining streaks observed by him is as follows:—“e and ¢ bright, broad; a, 3, y, 6 fairly bright; ¢ extends up to spot No. 4? ; e extends as far north as ¢.” He agrees with Mr. Elger in recording the “streaks as brighter than last night,” the 14th. He does not mention the sector; but I suppose he saw it. In speaking of ¢ extending to spot No. 4, does he refer to » ? 1870, October 6.—Mr. Gledhill recorded the floor as medium,=0-50; the streaks very bright. Mr. Elger, the same evening, described them as all faint, especially on the east ee side of the floor. Webb’s elbow and che de- ¢ —__ scribed as plain: asketch is givenofthejunction 2 = 2S much the same as it was seen on August 11, 1870 (interval 168 hours to meridian, see fig. 18, post, p- 289); the western strip of light on the floor __ appears to have subsided since October 4, as ob- 1870; Oct. 6.—T. G. E. Elger. served on May 10, compared with May 9, 1870 (see ante, pp. 273 & 277). Summary.—Sun’s altitude 28° 54':3 to 31° 42-7; tint of floor 0-54, esti- mated from curve. Streaks generally visible—sector, trident, and N.E. streak. The trident with stem was seen complete by Mr. Pratt on March 14, 1870. The streak n, which is very rarely seen indeed, was observed on April 12, 1870, and also on March 3, 1871. The streaks were mostly bright. Interval 108 to 120 hours. 1870, May 12.—Mr. Elger recorded the sector and streak y as very bright and well defined; (3 brightest near spot No. 3, and faint at border. The three arms of the trident, Z, e, ¢, faint, but easily traced ; the floor noted as very dark between e and e. The projection from Webb’s elbow, c, seen during the April lunation, although plainly seen, could not be traced so far to the south as before, and was not so sharply defined; indeed all the west portion of the N.W. marking (7.¢. the brightness in the N.W.) was hazy. [Haziness on the W. and N.W. part of the floor was noticed on April 11, 1870, by Mr. Elger. On April 12, 1870, by Mr. Pratt, who described it as very hazy. On June 10, 1870, by Mr. Elger.] The streak a east of spot No. 16 was very bright and well defined, and Webb’s elbow was very evident. The localities of spots Nos. 33 and 35 were the brightest. On the same evening and interval, Mr. Pratt described the sector as but faintly seen, and with the very same aspect as his first view of it, viz. a streak sloping more N.W. and 8.E. than usual, its western edge quite straight, its eastern edge slightly curved and fan-shaped ; all other streaks invisible. 1870, January 14.—Mr. Elger writes:—“The markings were at times very distinct, the east portion of y unusually so. I was unable to make out Webb’s elbow. The streaks n, 3, y, the sector, and trident were all di- stinctly seen. I much regret that the long spell of cloudy weather prevented me from observing the markings after the 14th instant, as I think those on the east side of the floor (y, , 3) were visible much sooner after the first quarter during this lunation than they were during the last. [Had they become brighter? See Interval 96 to 108 hours, 1869, December 15, ante, pp- 282-284.] There appeared also to be something abnormal about spots Nos. 1, 3, 4,5, and 17. Spots Nos. 6, 24, &e. I was unable to make out, although they were seen on the 14th of December, 1869. 1870, September 7.—Mr. Gledhill recorded the floor as dark, =0-66; streaks all very bright. OBSERVATIONS OF LUNAR OBJECTS. 285 1869, November 16.—Mr. Gledhill recorded the floor as very bright, =0°10; he says: “I never saw the floor so bright ; streaks very bright in- deed, definite and easy. I have drawn them as Isaw them. That drawn through No. 5 does not quite reach spot No. 1. Streaks @ and 6 [the bifurcation of ¢] meet halfway between the extremity of 6 (which originates at the foot of the inner slope in a bright elevation on the floor close to the foot, probably B. and M.’s mountain-peak 6) and spot Now.” 1869, October 17.—Mr. Gledhill recorded the floor “as dark as the south part of the Mare Serenitatis (?), registered as medium,=0°50.” He also re- corded a well-seen streak which covered spots Nos. 13, 19, and 16, parallel to the streak 3, which, if produced to E.N.E., would cut the north border of erater A outside Plato. The western portion is designated “ o,” the eastern a. Summary.—Sun’s altitude 31° 42"7 to 34° 115; tint of floor 0-57, esti- mated from curve. Streaks generally visible—the sector and N.E. streaks ; arms of trident not so frequently seen. The streaks were mostly bright, and especially so on November 16, 1869. Interval 120 to 132 hours. 1871, March 4.—Messrs. Gledhill and Neison record the floor as dark, =0-66. Mr. Neison speaks of the N.W. and S.E. portions of the floor as indistinct from broken light and streaks (see Report British Association, 1871, p. 81); and Mr. Gledhill speaks of the arms of the trident being very broad and diffuse. 1870, June 11.—Mr. Elger could only see the sector and the three arms of the trident, all faint. The same evening Mr. Gledhill recorded the floor dark,=0°66 ; streaks bright. Summary.—Sun’s altitude 34° 11'5 to 36° 17'5; tint of floor 0-60. Streaks generally visible—sector, arms of trident, and N.E. streaks except n. Interval 132 to 144 hours. 1870, April 14.—Mr. Elger described the streak 6 as very plain and bright, brighter than y. The middle, e, the brightest portion of the trident ; Fig. 15. a. 7 Plato, 1870, April 14.—T. G. E. Elger. n plain, brightest near the border, directed from the border towards spot Wo. 4; diminishing in breadth as it approached No. 4, it could be traced 286 REPORT—1872. almost up to it. The sector > did not appear to be equally bright, but seemed to consist of light-streaks directed towards spot No. 4 (see fig. 15, p- 285). The most interesting feature observed this evening was a project- ing arm from the west end of a, apparently a continuation of Webb’s elbow across the end ofa. Mr. Elger speaks of it as very plain, and occupying a position a little east of the curved streak c, which is far from being con- stant in its appearance, even if it should have a permanent character. On this ray or projection I made the following remark when I received the information :—‘‘ It appears to be a lateral translation towards the east of c, the portion of the curved streak west of spot No. 16, nearly in a line with Gledhill’s 9;” and I further said, “ this has much the direction but not the position of Elger’s h in the tinted plate of the ‘ Student,’ April 1870, p. 161.” Mr. Gledhill writes the same evening :—“ All streaks are very bright, y narrow and sharp, 7 not well seen far from the border, Webb’s elbow conspicuous.” 1870, May 13.—On this day Mr. Pratt saw no less than 42 objects on the floor of Plato, 26 spots and 16 streaks. The stem of the trident was well seen, also the streak yn as a fan or tongue. For Mr. Pratt’s remarks on the streaks, see Report British Association, 1871, pp. 88-91. On the same evening, May 13, Mr. Elger recorded the streak y as very bright; » and 6 faint, » the faintest on the east side of the floor; the three arms of the tri- dent faint; a bright and well defined; ¢ (the projection from Webb’s elbow) nearly as bright as at last lunation, very bright at the position of spot No. 19; sector very bright and well defined, a dark zone between its base and the border of Plato. [This dark zone is very unusual. | 1870, January 15.—At 6° Mr. Gledhill recorded “ all streaks bright; ” the brightest were a and (3; all others (y, 6, n, £) were seen well; y, which Was seen as a narrow sharp bright streak, not broader than spot No. 17, cut II E¥? a very little south of its middle point. The bright elbow (2) on the N.W. floor, at foot of slope of wall, was well seen. At 10" Webb’s Fig. 16. tase € a SS »._ fh sf Se —_s Oo. i=) = =" = — SS = SS = SSS! == xX ° == SSS = SS SSS —— = = ——— DS B= B @ Streaks on Plato, 1870, January 15.—J. Gledhill. elbow was seen to throw off an arm to the south, towards the streak 6 [this seems to have been a portion of the streak c]. From 12 to 13 hours, Mr. Gledhill says, <<‘ G is fine and bright, but I cannot trace it beyond spot No. 3. The sector is very bright ; it passes beyond spot No. 4 and meets streak 8 to OBSERVATIONS OF LUNAR OBJECTS. 287 the east of spot No. 3. The elbow on the N.W. border, just to the 8.W. of the end of the ridge which runs from the wall of Plato out to the N.W., is well seen; it sends out an arm to the south, which is forked. The northern prong, which extends to the west border, is the extension ‘0’ of the streak a, and the southern prong ¢ meets the streak § west of the point of junction of the streaks 6 and e.” Mr. Gledhill further says, “I also see another faint streak sent off from the long northern streak a up to the border; it cuts the border just east of the exterior ridge.” [This faint streak is marked y ; it has not been reobserved.| “A narrow faint streak runs from a point a little to the S.W. of spot No. 3, parallel to a, and joins the streak 6 between its junction with ¢ and e” [this streak is marked \]; “there is also a still fainter and shorter streak (,:) just south of a, or rather its continuation, “0.” I tried to see f and the streak \ as a continuous streak, but could not; neither did I find that they were quite in the same S.W. direction, but they were very nearly so indeed. » could not be traced quite up to spot No. 4; on the border it was a large square bright streak resting against the foot of the terrace (lowest) of the inner N.E. wall.” The streaks X and p, discovered this evening, have been observed only by Mr. Gledhill; it is probable that they are too faint to be seen with smaller apertures than 9 inches; they have been seen occasionally between January 15, 1870, and March 6, 1871. 1869, August 20.—See ante, p. 253. 1870, November 6.—Mr. Gledhill recorded the floor as dark, =0-66 ; streaks very bright. Mr. Elger says of them, “all faint and difficult to trace, those on the east side of the floor especially.” Summary.—Sun’s altitude 36° 175 to 37° 57'8; tint of floor 0-62, esti- mated from curve. Streaks generally visible—the sector, east and middle arms of trident, and the N.E. streaks a, 3, y, and 7; the whole variable in brilliancy. On January 15 and May 13, 1870, more streaks were seen than usual, especially on May 13. Interval 144 to 156 hours. 1871, March 5.—Mr. Elger described the markings as all faint. 1869, July 22.—Mr. Gledhill could see nothing on the floor, which he re- corded as very dark. 1870, August 10.—Mr. Neison recorded the floor as medium, =0°50, and Mr. Gledhill recorded it as dark,=0-66; he described the streaks as bright, and y not far from the border, as usual. 1869, December 17.—Mr. Gledhill recorded the floor as dark,=0°66: he described the sector as bright, and streak a as very bright; § and y as bright, é, e, and Z less bright, but not equally so; 7 the faintest, but bright near the border of Plato. Mr. Gledhill describes a luminous broad patch, which, starting from the inner border of Plato, about B. & M.’s object ¢ [the most northern peak on the west border], joins the streak a; it also sends off a luminous streak to 6. The luminous patch is brighest and broadest near the foot of the inner slope. [The broad patch is most probably Webb’s elbow, and the streak to 6 is c—W. K. B.] 1870, October 8.—Mr. Elger recorded the markings as generally faint, except a, Webb’s elbow, andc. 3 and y were much brighter than y; the trident faint. Summary.—Sun’s altitude 37° 57':8 to 39° 9-2; tint of floor 0-64, esti- mated from curve. Streaks generally visible—sector, trident, and N.E. streaks; they alternated in brightness. 288 REPORT—1872. Interval 156 to 168 hours. 1870, May 14.—Mr. Elger recorded the markings all faint; a and Webb’s elbow well seen. At the point of junction of a, c, and i (qy. position of spot No. 19) the floor was very bright. Mr. Gledhill on the same evening re- corded the floor as dark,=0-66. Streaks bright, sector and a the brightest ; elbow well seen; \ and p were not seen. 1869, August 21.—See ante, p. 253. 1870, December 7—Mr. Elger recorded all the markings as faint, except cand p. Mr. Gledhill recorded the floor as dark,=0-66. 1870, September 9.—Mr. Elger recorded y and #3 as very faint. 1869, October 19.—Mr. Gledhill recorded the floor as dark as the south part of Grimaldi; it is registered as =0°70. Mr. Gledhill furnished the annexed sketch of the streaks a, /, n, and y, with the sector, unaccompanied by any remarks; it would appear from this that the whole of the 8.W. part of the floor was in some way obscured (see pp. 255 to 262). Mr. Pratt’s remarks on the same evening confirm this idea; he says, “ Trident near spot No. 1 invisible, only the ends of the arms detected with difficulty.”’ He also specifies the posi- tions of the dark localities on the floor : “‘ darkest near m, 1. e. the mountain on Plato, October 19, 1869.—Gledhill. the north border.” [It was this locality which in May 1870 was noticed to be very light, see pp. 273 and 277.] The next darkest area was closely S.W. of B. and M.’s rock ¢, next above it, S.W. of spot No. 1, and the lightest of the dark spaces N.W. of the rock ¢. We have here four areas characterized by a darker tint, the floor itself being registered as more than ordinarily dark, one of the darker spaces being accompanied by an obliteration of nearly the whole of the trident. The localities of the darker areas are shown on the annexed engraving, containing Mr. Gledhill’s streaks. Summary.—Sun’s altitude 39° 9°2 to 39° 50"5; tint of floor 0°65, as estimated from curve. Streaks generally visible—the sector, east and middle arms of trident, also the N.E. streaks a, 3, y; not so frequent. Interval 168 hours to meridian passage. 1870, April 15.—Mr. Gledhill recorded the floor as dark, =0-66. Of the streaks seen, the sector and a and /3 are described as very bright. The same evening Mr. Elger described the sector and y as the brightest markings on the floor; y, 6, and trident very faint. The projecting arm (registered as ¢, see ante, p. 286) observed on the 14th appeared brighter this evening, and extended further towards the west arm of trident, which it almost touched (compare with Mr. Gledhill’s sketch on January 15, 1870, ante, p. 286) ; its direction formed an obtuse angle with the direction of the west arm and with the streak a; the streak “‘o” absent. 1871, March 6.—Mr. Gledhill recorded the floor as dark, =0-66. The streaks and sector bright and well seen, the two fainter streaks \ and p in- cluded. These streaks have been seen on seven occasions before meridian passage. 1870, June 13.—Mr. Gledhill recorded the floor as dark, = 0:66; the streaks and spots bright, but not well seen. Mr. Gledhill has the following OBSERVATIONS OF LUNAR OBJECTS. 289 remark :—‘“ The effect of a low power on Z and e (the east and middle arms of trident) is ‘to show their southern extremities as bright hazy spots, and to hide their character as lines of light; a higher power shows the whole line as a nearly (or quite) uniformly bright streak.” Under this interval and date I have the following memorandum :—“ It is a little remarkable that the streaks (3, , and, still later, y should exhibit such variations as to accord with a decrease of brightness, becoming lost to Mr. Elger, but still lingering in the Halifax refractor. With regard to the tint of the floor, observation has established that it becomes darker under a high sun. Three hypotheses may be suggested in explanation :—First, Will the heating of a bare surface produce a darkening of that surface? Second, Increase of angle of illumination, we know, occasions a darkening of the vegetable covering of the earth: is it so with the moon? Third, Can there exist within the mountainous enclosure of Plato absorptive clouds the results of vaporization by long-continued sunshine ?” 1869, July 23.—Mr. Gledhill recorded the sector as fairly well defined. 1870, August 11.—Mr. Elger described the markings on the east side of the floor » and f as very faint ; the sector and y were not so faint ; the three arms of the trident, Z, e, and e, were plain ; a, with Webb’s elbow, were seen, as in April and May last, very distinct. The drawing gives the elbow and the part of c as forming a sharp angle with a. Fig. 19. Fig. 18. —— — a UL Plato, 1870, Aug. 11.—T. G. E. Elger. Plato, 1870, Oct. 9.—T. G. E. Elger. 1869, September 20.—Mr. Gledhill recorded the floor as dark, = 0°66, not quite so dark as the south part of Grimaldi; the sector easily seen. Same evening Mr. Elger registered the N. boundary of the sector as extending from spot No. 4, just past No. 7, to the east border. This appears to have been an extension of the sector, including the streak y. For Mr. Elger’s drawing of this day, see history of streak a, p. 263, and for remarks, see ante, p. 262. 1870, October 9.—Mr. Elger recorded the sector as plain, y faint, trident faint. ‘‘I again suspect,” says Mr. Elger, “the connexion between the eastern and central arms of the trident observed by Mr. Pratt.” Mr. Elger gives a sketch of a and Webb’s elbow, with c in a line with the elbow, join- ing ¢, the west arm of the trident. The streak c, from Webb's elbow to the west arm of trident, is curved, the concavity towards the west border (see In- terval 168 to 156 hours, post, p. 291). Nothing appeared to occupy the area between the border and streak except the plain floor; the streak “‘o” en- tirely absent. See intervals 132 to 144 hours, and 168 to meridian, ante, pp. 285, 288). Summary.—Sun’s altitude 39° 50°5 to 40° 0°0; tint of floor 0-66, estimated from curve. Streaks generally visible—the sector, the middle arm of trident most frequent, the eastern arm next, and the western arm 1872. x 290 REPORT—1872. but seldom ; the streak a more frequent than y, 8, or n. Most of the ob- servations during this interval have shown the N.W. part of the floor in proximity with the border as destitute of streaks. Interval meridian passage to 168 hours, 1870, March 17.—Mr. Gledhill recorded the floor as dark, = 0-66; he de- scribed the sector and streak a as easy objects, bad as was the night; the southern streaks were faintest, a and the sector brightest, then came n, y, /. 1870, July 13.—Mr. Gledhill recorded the floor as dark, = 0°66; streaks very bright. 1870, September 10.—Mr. Elger recorded the sector and trident (three arms, ¢, e, ¢) as very distinct, » scarcely discernible, and 6 brightest near the rim. Summary.—Sun’s altitude 40° 0'-0 to 39° 505; tint of floor 0:67 to 0-66. Streaks generally visible—the sector and the east and middle arms of trident; the N.E. streaks less frequent. Interval 168 to 156 hours. 1870, April 16.—Mr. Gledhill recorded the floor as dark, =0-66 ; the streak a is described as bright and sharp. The same evening Mr. Elger writes :— “The markings appeared as on the previous night, with the exception of the projection from Webb’s elbow (c), which I could not see.” This is note- worthy, as on the 14th and 15th it was evidently increasing, now it seems to have suddenly disappeared ; it does not appear to have been observed by Mr. Gledhill. 1871, January 7.—Mr. Elger recorded the markings all plain. The curved marking on the N.W. side of floor appeared exactly as shown in the ‘ Student,’ April 1870, p. 161; the elbow 7 was distinctly seen. The new marking p was also well seen; spots Nos. 5 and 17 were connected by it: at times y seemed to be a prolongation of it; it could not be traced through the sector. The observation by Mr. Elger of « and ¢ with Webb’s elbow, being exactly as given in the ‘Student,’ is interesting, especially as contrasted with the observations, also by Mr. Elger, of the prolongation of the elbow at a sharp angle with a (see ante, pp. 284, 289), from which it may be inferred that the streak is variable in position; and this gives further countenance to the con- clusion that the N.W. portion of the floor is the most variable. 1870, August 12.—Mr. Pratt recorded the floor as very dark, Mr. Neison recorded it as dark. Mr. Pratt says :—‘ In moments of best definition the area comprised between spots Nos. 19, 1, and 4 and the northern and _ north-east rim was not nearly so well displayed as the rest of the floor, giving a strong impression of an obscuring medium existing there. The dark parts of the floor were darker near the rim.” 1869, December 19.—Mr. Gledhill recorded the floor as dark, =0-66; the sector very bright, and, after spot No. 1, the most striking object; a bright, 3, e, € less bright; the prolongation of the sector to spot No. 4 fairly seen. 1869, September 21.—Mr. Gledhill recorded the floor as not so dark as the extreme south part of the floor of Grimaldi. Of streak ¢ he says, ‘‘ Spots Nos. 13, 19, and 16 are well seen, a streak of light connects them; it is a thick, dense streak, not faint and diffuse.” The sector he describes as “bright, permanent.” 1869, November 19.—Mr. Gledhill recorded the floor as dark, = 0-66. In addition he gave the following remarks :—<“‘ The sector bright and well de- al OBSERVATIONS OF LUNAR OBJECTS. 291 fined; as usual, of all the streaks a is always brightest; 6 is one of the brightest, but less so than a; y is similar; y is bright and mostly well seen ; f, e, 0, and 6 are always the faintest and broadest; e and & are almost always seen, 6 not always; that portion of a which lies to the west of spot No. 16 is not always seen” [this answers either to “0” orc]. Mr. Gledhill described and figured a short streak from the N.W. border very bright. On this I remark :—‘‘ The elbow of light tint described by the Rev. T. W. Webb as seen by him on Oct. 24, 1855 (see monogram of the Mare Serenitatis, p. 13), was well seen (and very bright) by Mr. Gledhill, 1869, Nov. 19, moon’s latitude 4°10'+8. On the 16th the moon’s latitude, 5°, was more favourable for seeing it; but it does not appear, from Mr. Gledhill’s observations, that it was then visible.” See Mr. Gledhill’s remarks on the streaks y, 6, and 7, ante, p. 283. It would appear that, so far as the streaks are concerned, the N.W. part of the floor exhibits the greatest amount of variation. Looking at Mr. Gled- hill’s diagram of November 19, and taking into consideration the general structure of the floor, we have in the S.W. the arms of the trident radiating from spot No. 1; in the S.E., the sector fan-shaped, the sides radiating from spot No. 4; inthe N.E., 6 specified by Mr. Gledhill as one of the brightest streaks from spot No. 3, and a, 2, n, and y more or less parallel. Now bearing in mind that Plato has suffered dislocation from a fault from N.W. to $.E., that spot No. 1 is opened upon the highest part of the floor, and that spots Nos. 3 and 4 occur on the N.E. slope from the fault, it is not a little significant that the directions of the streaks are from higher to lower ground. Mr. Pratt suggests that the light-streaks are coincident with formations analogous to “spurs” from the chief centres of the residual activity on the floor (see Report Brit. Assoc. 1871, p. 95). 1869, November 19.—On this evening Mr. Gledhill observed the streak a and its continuation “o”; he also saw, forking from the locality of spot No. 16, the curved streak c, convex to the west border (see ante, pp. 263, 264, 285, 289). On contrasting Mr. Elger’s and Mr. Gledhill’s sketches of Sept. 20 and 25 respectively with Mr. Gledhill’s of Nov. 15 and 16, and espe- cially of Nov. 19, the existence ofc and “0” as separate streaks is undeniable. On Sept. 20 and 25 “0” was distinctly recorded by two independent observers ; it was also recorded on Oct. 25, 26, and 27 by Mr. Gledhill. On Noy. 15 it was not seen by Mr. Gledhill, nor on the 16th, the streak ¢ passing over and beyond spot No. 13. On Noy. 19 there was a great development of light- streaks, the N.W. part of the floor exhibiting the curved streak ¢, with “0” and a and Webb’s elbow in contact with the N.W. border. Mr. Pratt recorded the N.W. streak making a contact with the N.W. border, near spot No. 16, on Nov. 15. 1870, October 10.—Mr. Elger recorded y and f as plain, n faint; the con- nexion by p between the centre (e) and eastern (¢) arms of trident seen. Trident and markings on N.W. side of floor as on the 9th of October. Spot No. 5 is recorded as seen on the east edge of the east arm of trident (see ante, pp. 254 and 275). Messrs. Pratt and Neison recorded the floor as “medium,” and Mr. Gledhill recorded it as “very dark.” The lighter tint, as seen by Messrs. Pratt and Neison, is exceptional. Mr. Gledhill mentioned that the sector was composed of bright lines radiating from the apex to the base (see ante, p. 285). Mr. Elger witnessed a similar appearance on April 14, 1870. (Interval 132 to 144 hours.) Summary.—Sun’s altitude 39° 505 to 39° 9°2; tint of floor 0°66 to 0-65. Streaks generally visible—the sector, east and middle arms of trident, with x2 292 REPORT—1872. the northern bifurcation of the western arm 6, the N.W. and N.E. streaks except 3, which is less frequent. Interval 156 to 144 hours. 1870, July 14.—Mr. Gledhill recorded the floor as dark=,0-66. The sector and streaks seen were dense and bright; the streak » was seen near the border; a had a condensed brightness in the middle; the south ends of the south streaks ¢ and e were brightest. With powers 150 and 115 the sector appeared to be condensed at the apex. On the same night (July 14) Mr. Ingall speaks of the floor being, at times of fine definition, covered with spots of light. I have registered it as very light, = 0-00; it must, however, be considered as exceptional, the floor being dark under a high sun. This extra- ordinary spottiness of the floor appears to be of the same nature as the ap- pearances of the Mare Crisium, related in Webb’s ‘ Celestial Objects,’ third edit., pp. 82 & 83. Mr. Ingall gives the distribution of the markings as follows :— First. A large white cloud stretching half round the crater-floor from spot No. 14 to spot No. 3. This white cloud occupies the position of the middle and the east arms of the trident and that of the sector, with its extension to spot No. 3, the sector and the two arms of the trident being connected. It is remarkable that this cloud is entirely separated from the border; and, so far as the sector is concerned, we have a similar observation by Mr. Elger on May 13,1870. (See Interval 132 to 144, ante, p. 286.) Second. A detached fainter cloud on the N.W. part of the floor, which occupies precisely the posi- tion of the curved streak c, with its convexity tewards the border ; it incloses spot No. 16. Zhird. A small detached mist on the S.W. part of the floor, which occupies the position of Gledhill’s streak 6. Fourth. A curious brush of light adjoining the N.W. border (Webb’s elbow), much brighter near the wall. The difference between Mr. Gledhill’s and Mr. Ingall’s observations, particularly as regards the absence of streaks near the border, except Webb’s elbow, which characterizes Mr. Ingall’s, is doubtless due to the difference of apertures. The elbow appears to have been seen well in both instruments. 1869, August 23.—See ante, p. 253. 1870, November 9.—Mr. Elger recorded the markings as faint, except the sector and y; the latter is described as unusually bright. 1869, October 21.—Mr. Gledhill described the streaks a, 3, n, and y as seen on the 19th, but brighter; he also described the apex of the light- sector as reaching to about spot No. 3; he has, further, this remark :—* On the S.W. rim of Plato, near or at the foot of the inner slope, are three bright foci; from these the three great bright streaks on the floor proceed,—(1) a line from the uppermost, on the 8. border, produced to N.E., cuts spots Nos. 1 and 3 [this must be the streak €]; (2) a line from the next lower produced passes just S. of spot No. 3 [this is Gledhill’s 6]; (3) a line from the lowest, towards the N.W., cuts the E. border of Plato just below or N. of II E¥?. I. could not trace the streaks well which proceeded from these foci. On the same evening, with the Royal Astronomical Society’s Sheepshank’s telescope No. 5, aperture 2°75 inches, power 100, I observed Plato and found the floor very ill-defined, the sector the only light marking visible; it was brightest towards the S.E. border. Definition, Earth’s atmosphere ‘ very bad, much boiling and fluttering.’ The definition on the moon was very irregular; Plato was very difficult to observe, while the markings around Copernicus and Kepler were admirably seen. Idetermined the following tints :—the surface around Kepler =5°:0; Plato, the S.E. part of sector, =4°-8; Mare Imbrium, 8. of Plato, =4°-4; Mare Imbrium, between the Mountain Chajorra and Straight chain, OBSERVATIONS OF LUNAR OBJECTS. 293 =3°6; Plato, the W. part of floor, =1°-6 ; Grimaldi, 8. part of floor, =0°-6. These determinations exhibit increase of brightness with increase of num- bers—Grimaldi the darkest, surface around Kepler the brighest. My estimate of the tint of the floor of Plato, on the scale adopted for comparison with the sun’s altitude, was 0°66, or dark; this is about a degree brighter than the 8. part of the floor of Grimaldi.” 1870, September 11.—The markings, as observed by Mr. Elger, were all indistinct. Summary.—Sun’s altitude 39° 92 to 37° 578; tint of floor 0°65 to 0-64. Streaks generally visible—the middle arm of trident, sector, and y the most frequent; the east arm of trident and the N.E. streaks less frequent. Interval 144 to 132 hours. 1870, April 17.—Mr. Gledhill recorded the floor as dark, = 0-66, and the N. streaks as brightest; 6 as bright as the sector, and y, n seen only at the foot of the slope. 1869, May 27.—Mr. Gledhill records the sector as ill-defined below. 1871, January 8.—Mr. Gledhill described the streaks as having been well seen ; one, not named, as very sharply defined, bright, narrow, and straight. This I apprehend to be a, as Mr. Gledhill generally describes it as such. 1869, December 20.—Mr. Gledhill recorded the floor as dark, =0-66. Streak seen (bright); sector a fine striking object. On the same evening Mr. Pratt recorded the markings as peculiarly indistinct, from which he considered the apparent difference of form which he observed to arise. The trident near spot No. 1 was shaded off. The greatest peculiarity shown by Mr. Pratt in his diagram is a bifurcation in the neighbourhood of streak £, or rather two streaks from spot No. 3 instead of one. Mr. Elger on the same evening showed one only, very narrow. and remarked the portion of the floor between 8 and y to be very dark. Mr. Elger further said, “a remarkable feature observed was the strip of light (streak y), which during the whole evening was by far the brightest marking on the floor.” This streak is not recorded by Mr. Gledhill, who noticed the sector as being the most striking object. Mr. Elger saw a part of ¢ and Webb’s elbow 7, which he described as the brightest on this part of the floor. 1870, August 13.—On this evening the floor was recorded as “ dark” by three observers, Mr. Pratt, Mr. Gledhill, and Mr. Neison. Mr. Pratt re- marked :—‘‘ On this evening, as well as 1870, Aug. 12, the tint of the dark portions of the floor was much intensified close to the rim; it was the case all round, but especially so between 6 and Z, between e and Z, and between Band yn.” Mr. Gledhill observed the streaks to be very bright ; they appeared to stand out in relief. Compare with Mr. Pratt’s suggestion (1870, October 17) of the light-streaks being analogous to spurs (Report, 1871, p. 95). 1870, October 11.—Mr. Elger recorded the streak n as very faint. Summary.—Sun’s altitude 37° 57'°8 to 36°17°5; tint of floor 0-64 to 0:62. Streaks generally visible—the sector much more frequent than the others ; next in order east arm of trident, y, G, anda. The N.W. streak and middle arm of trident less frequent, the others rarely seen. : Interval 132 to 120 hours. 1870, March 19.—Mr. Gledhill recorded the floor as dark, =0-66 ; he de- scribed the sector and a as very bright, the brightest on the floor. 1870, November 10.—Mr. Elger described the markings as better seen 294: REPORT—1872. on this evening than on any other during the lunation. Webb’s elbow and c well seen. Summary.—Sun’s altitude 36° 175 to 34° 115; tint of floor 0°62 to 0:60. Streaks generally visible—the sector, trident, and N.E. streaks. Interval 120 to 108 hours. 1871, January 9.—Mr. Gledhill’s remarks are the same as on January 8, under interval 144 to 132 hours. See ante, p. 293. 1869, December 21.—Mr. Gledhill recorded the floor as dark, =0-66. Streaks all fairly seen, except 6 and y. [I suppose by all Mr. Gledhill means those which he has lately seen; I have accordingly recorded b, a, e, £, 0, and y.] Mr. Gledhill mentioned none as bright except a and the sector, and they were not bright and clear as usual; a was perhaps the brightest. A bright brush of light was seen near B. & M.’s 6 on the border, which appeared to merge into aand 6. A line through spots Nos. 17 and 1, produced to the N.W. border, cut the border just above or to the south of the brush, which is Webb’s elbow z. The brightest portion of the border is described as that to the north of the streak a, the east end of the bright part of the border being much the brightest. A diameter at right angles to the longitudinal diameter of Plato passing through spot No 1 would cut the east and brightest ex- tremity. Mr. Gledhill adds, ‘‘ It seems a long narrow basin.” ~ Summary.—Sun’s altitude 34° 115 to 31° 42"7; tint of floor 0-60 to 0-57. Streaks generally visible—middle and eastern arm of trident, sector, y and a; others less frequent. Interval 108 to 96 hours. 1871, February 8.—Mr. Pratt described the streaks as ill-defined, except 1, which was very fairly seen and much brighter than any part of the trident. 1870, July 16.—Mr. Gledhill recorded the floor as medium, =0-50; he described all the streaks as bright, except \ and y, which were faint. a, #, y, 6, €, € were all well seen: 7 was seen near the border, and a had a condensed central portion; the south streaks (£,¢) were brightest at their southern ends. Mr. Gledhill does not mention the sector; but it is very probable that he saw it, by his recording all as bright. 1869, August 25.—Mr. Gledhill recorded the sector as “ very faint” at 11 hours; at 13.30 he recorded it as ‘ fine.” 1870, September 13.—Mr. Gledhill recorded the floor as dark, =0-66. The streaks were very bright and well seen. Mr. Gledhill measured the positions of streaks Z, e, 6, and a with the sector (see Report Brit. Assoc. 1871, p. 66). Summary.—Sun’s altitude 31° 42-7 to 28° 543. Tint of floor 0-57 to 0-54. Streaks generally visible—the sector most frequent, three arms of trident ; N.E. streaks much less frequent. Interval 96 to 84 hours. 1869, December 22.—Mr. Gledhill recorded the floor as dark, =0-66. Streaks all faint; «a the brightest; 6, , and y difficult; e, Z, and sector fairly seen, but faint. The brightest part of the inner wall was north of streak a, as well as all the west border. Shadows were already under the east border. Time 12 hours. At 12.30 Mr. Gledhill recorded the part of the inner north wall of Plato, from which the brush of light proceeded, as much less bright than the adjacent portions east and west. 1870, August 15.—Mr. Pratt recorded the floor as dark, =0-66, but OBSERVATIONS OF LUNAR OBJECTS. 295 paling; the darker margins of the shaded parts of the floor were still visible as on the 12th and 13th, but not in such striking contrast. 1870, October 13.—Mr. Pratt remarked that all the objects on the floor appeared fainter than usual. This, which especially applies to the light- streaks, which were very well defined at their edges, is remarkable when Si) many spots are detected as on that evening. Summary.—Sun’s altitude 28° 54°3 re 25° 49"5; tint of floor 0-54 to 052. Streaks generally visible—the sector principally, the others but seldom, especially the N.E. streaks. Interval 84 to 72 hours. 1869, August 26.—Mr. Gledhill recorded the sector as very faint. See ante, p. 254. 1870, September 14.—Mr. Gledhill recorded the floor as medium or light, =0-42; streaks faint, but well seen. Mr. Neison recorded the floor as mo- derately dark, =0:58, mean 0- 50, or medium. Summary. Sun's altitude 25° 49-5 to 22° 31! 3; tint of floor 0°52 to 0-49. Streaks generally visible—sector and eastern and middle arm of the trident. Interval 72 to 60 hours. 1869, July 28.—Mr. Gledhill recorded the sector as faint and diffuse. 1870, August 16.—Mr. Pratt recorded the floor as medium, =0-50, and much paler than on the 13th (see ante, p. 293, interval 144 to 132 hours). The darker parts of the shaded portions of the floor were but just perceptible with attention. 1869, September 25.—Mr. Gledhill described the tint of the floor as “ not much deeper than that of the Mare Imbrium.” He appears to have seen streaks c [“a strong streak of light connecting the spots Nos. 16, 19, and 13, which were not seen” |, « [ “a diffuse streak of light runs east from spot No. 3 parallel to that crater along spots 16, 19, 13”’], and the connexion of « with the sector [‘‘ a streak is seen from spot No. 4 to spot No. 3, as if a continuation of the sector” |. On these I have the following remark :—“ ¢ from the 8.W. of spot No. 13 (not seen) to. IJ E¥? on the east border made out in separate streaks.” The continuous direction of these streaks forming one white line was seen by Mr. Pratt on August 17, 23, 26, and 28 (see pp. 252— 254). Mr. Gledhill described the three arms of the trident as follows :— “ fe] A rectangular luminous patch stretches from the south rim of Plato to spot No. 14, embracing it and passing on till nearly in a line with spot No 1, at which point a luminous streak [e] shooting from the rim and em- bracing spot No 22 meets it. This latter streak seemed to become a mere line as it approached the streak e.” The 8.E. arm [Z] is described as “an irregular rectangular patch of light running from the south rim to spot No. 1 nearly.” It does not appear that Mr. Gledhill observed the junction of the three arms. The N.W. arm [e] is described as “ very bright, the brightest, the greatest brightness being close to the rim of Plato.” The central arm [e]is described as “less bright,” and the S.E. arm [¢] as “still fainter.’ The apex of the sector is described as beyond spot No 4, distinctly enough extending to the streak ) running from spot No. 3to rim. The following note is appended by Mr. Gledhill :—« I could not see the limits of the three arms of the trident as they approached the centre.” From his sketch Mr. Gledhill appears to have seen the streak “0” and its continuation a, his delineation being almost identical with Mr. Elger’s of September 20. It is not at all improbable that a change had occurred in the N.W. part of the 296 REPORT—1872. floor, ¢ and x being much fainter and the western part of c obliterated, even in the larger aperture of the Halifax refractor, as compared with the seeings and drawings of Mr. Pratt in August 1869; the change consisted in the fading of x and ¢ and the intensification of a and “0.” For Mr. Gledhill’s drawing see ante, p. 263. 1870, October 14.—Messrs. Gledhill and Pratt both recorded the floor as medium, =0°50. Mr. Pratt remarked that the streaks were difficult, con- sidering the number of spots that were visible. Summary.—Sun’s altitude 22° 313 to 19° 2"0; tint of floor 0°49 to 0:45. Streak generally visible, the sector. Interval 60 to 48 hours. 1869, August 27.—See ante, p. 254. 1869, October 25.—Mr. Gledhill recorded the floor as light, =0°33, the sector as ‘‘ very faint, and differing but little in brightness from the floor to the east of it; its base was bounded by three craters, Nos. 26, 27, and 28, on the inner slope of Plato; its apex extended beyond spot No 4, and it eut streak £ a little east of spot No. 3:” the streak y is described as bright, sharp, and narrow. Summary.—Sun’s altitude 19° 2’0 to 15° 23°3; tint of floor 0:45 to 0:42; the streak 3 most frequent. Interval 48 to 36 hours. 1869, December 24.—Mr. Gledhill recorded the floor as light, =0-33; the sector as large and diffuse, scarcely brighter than the adjacent floor ; outline not sharp. The streaks 6, e, Z about as faint as the sector; }, yn, and y not fairly seen ; all are faint. All along the north border of the pointed shadow from B. & M s ¢ Mr. Gledhill saw a fringe of light (see Interval 24 to 36 hours, 1869, Dec. 12, ante, p. 275; also quotation, Elger’s Observation 1871, Noy. 20, post, p. 299), i. e. the floor adjacent to the north edge of this shadow was quite bright up to the foot of the border of Plato. a appeared brighter than any other streak. 1870, August 17.—Mr. Gledhill recorded the floor as rather bright, regis- tered at 0°40: streaks faint; a was the brightest, but it was neither dense nor broad, nor could it be said to be really bright; the others were fainter than it. The sector had ill-defined edges. Summary.—Sun’s altitude 15° 23'3 to 11° 38"2; tint of floor 0-42 to 0-39. Streaks generally visible—sector and eastern ‘arm of trident, others not so frequent ; all recorded as faint. Interval 36 to 24 hours. 1870, March 23.—Mr. Gledhill recorded the floor as medium, =0-50. He described the sector and a as easily, but not well, seen ; a was diffuse, and ex- tended up to the north border [in December the brightness near the border subsided after interval 60 to 72 hours, see ante, p. 268]: 6, e, seen with some difficulty ; they were much fainter than a and the sector. The shadow of B. and M.’s was on the floor, and the adjacent floor to the N.W. was very bright, much brighter than a or the sector. The bright space was directed to spot No. 4, and it extended one third of the distance from the border to No.4. Mr. Gledhill could not determine its shape; but it appeared to him as an intensified form of the streak y, and was the most striking object on the floor. 1870, July 19.—Mr. Gledhill recorded the floor as bright, =0:33. The streaks but little brighter than the floor ; none were striking objects. 1869, August 28.—See ante, p. 254. OBSERVATIONS OF LUNAR OBJECTS. 297 1870, November 14.—Mr. Pratt at 10 hours recorded as follows :— “Definition very bad; a large area of the floor to the S.E. shaded off deli- eately, as of a slightly lower level. Tint of unshaded part a little darker than the surrounding Mare, that of the shaded portion as dark again. The out- line of the shaded part conforms roughly with that area of the floor adjoining the inner edges of streaks 6 and x.” [Mr. Pratt has furnished a sketch, dated 1870, November 15, 11.50, which I apprehend from his letter, combined with the date of his observation, should be November 14, and that the S.E. part of the floor should be S.W.; with these corrections the sketch and observa- tions.agree.]| Mr. Pratt’s record proceeds thus :—‘ These observations have much confirmed in my own mind some previous ideas, faintly shaped by former views, that the light-streaks are merely parts of the floor relatively raised and perhaps more rugged and broken (hence one cause for their con- trast in tint with the rest of the floor), and that the spots are, especially several of them, raised: perhaps they are the centre points of the latest activity, which also possibly produced the streaks by raising them above the level. Was it by successive deposits of ejected material? One would have expected a lava- like deposit after reading Piazzi Smyth’s ‘Teneriffe.’” [The contrast of colour is a most important study, which may be greatly advanced by continuous observations of the variations in intensity of two or more neighbouring spots. | On the same evening, November 14, Mr. Gledhill recorded the floor as light, =0-33, and the streaks as very faint. Mr. Gledhill noticed that the floor was separated into a lighter and darker portion, the line of separation con- sisting of the west edge of the sector produced to meet the north border. The floor to the east of this line is bright, and to the west darker. [This line would be nearly in the direction of the fault in the neighbourhood of which the surface is raised, and the difference of tint is most likely produced by the obliquity of the sun’s rays.] Mr. Pratt’s sketch is in perfect accordance with Mr. Gledhill’s observations. 1869, October 26.—Mr. Gledhill recorded the floor as bright, =0°33. The spots, except No. 1, were not readily seen; the sector and streaks were faint. Summary.—Sun’s altitude 11° 38'2 to 7° 48°1; tint of floor 0-39 to 0°36. Interval 24 to 12 hours. 1869, September 27.—Mr. Gledhill recorded the floor as not so dark as the Sinus Iridum, nor so light as that of Archimedes; it is registered as light, = 0-33. Mr. Gledhill described the streak c as a broad band of brightness, width about one third the distance from the north rim to spot No. 1, enclosing spots Nos. 13, 19, and 16; the streak § he described as a faint belt from spot No. 3 to the east edge of Plato. The limits of both bands were very indefinite. Summary.—Sun’s altitude 7° 481 to 3° 548; tint of floor 0°36 to 0:33. Interval 12 to 0 hours. 1869, October 27.—Mr. Gledhill recorded the sector as very faint and indefinite ; the streaks all very faint indeed, yet all seen at best moments. Floor registered as light, =0-33. 1870, November 15.—Mr. Gledhill recorded the floor as light, =0-83, but consisting of two parts, the eastern light and the western dark. Mr. Pratt’s observations, 1869, August 28, interval 36 to 24 hours, were similar in cha- racter. See Report Brit. Assoc. 1871, p. 86. Summary.—-Sun’s altitude 3° 54':8 to 0° 0'; tint of floor 0°33 to 0:30. 298 REPORT—1872. Interval 0 to 12 hours. (Near the summer solstice.) In the Report for 1871 (see Report Brit. Assoc. 1871, pp. 94, 95) a de- scription of sunset, as observed by Mr. Pratt, is inserted. Mr. Pratt’s letter was accompanied by a drawing, a copy of which is given below. Fig. 20. 1870, Oct. 17, 11" to 12", Sunset observed by Mr. Pratt. APPENDIX, Although the epochs of the following observations are not within the period embraced in the foregoing discussion, they bear so intimately upon the results that a notice of them may not be inappropriate. On November 20, 1871, I observed sunrise on Plato with the Royal Astronomical Society’s Sheepshank’s No. 5 telescope, aperture 2°75 inches, power 100. At 5.50, Greenwich mean time, I made the following record :-— “‘ The appearance of Plato, examined at intervals of a few minutes since 4.35, has been very curious to-night. I have been unable to divest myself of the impression that a kind of sparkling or agitation played over the dark floor deep in shadow. This appearance has latterly greatly increased, and now there are two well-marked regions (but by no means distinct streaks of sun- OBSERVATIONS OF LUNAR OBJECTS. 299 light) north and south on the floor ; they are parallel, and are separated by a darker region of an intensity equal to the west part of the floor, which ex- tends over about one third of the longest diameter.’ At 6.0 the record runs thus :—“ There is no: doubt of the northern streak of sunlight existing on the floor, and traces of the southern streak are becoming apparent. Not the slightest appearance of the streak seen by Bianchini (see Report Brit. Assoc. 1871, p. 73) has been observed. 6.20. The northern and southern streaks of sunlight are both decided ; their western extremities lie upon the line of fault from N.W. to S.E. The long shadow of the peak 6 is now seen; it aligns with the north part of II E¥? and the rock @, or rather the inlet between them and the bases of the first group of mountains of the Alps west of Plato. 6:30. The light of the northern streak is the most intense, although both are faint. 6.45. The southern streak of sunlight is greater in extent (width) than the northern, perhaps nearly double. Although definition on the moon’s surface is generally good, there appears to be a want of defining power within Plato. Occasionally I see something approaching to well- defined shadows, but greatly inferior to what I usually see with this glass. The streaks of sunlight do not come out with that intensity which I re- member to have seen them on January 10, 1870. 7.10. Sunlight on Plato increases in intensity, but the shadows are deficient in definitioh, and the streaks terminate on the east at some distance from the border, indicating a considerable dip of the floor, if, indeed, the sunlight be reflected from the true floor. 7.15. In best moments I see the northern edge of the shadow of the peak y. The general character of the reflected sunlight is faint. The north edge of the shadow of y aligns with the south part of II E¥? and the sum- mits of the group of mountains west of Plato, the bases of which aligned with the shadow of 6 and the north part of II E¥?. The floor appears to be much darker than the site of Newton to the south.” On the same evening Mr. Elger observed and sketched Plato ; his drawing, fig. 21, made at 7.30, aperture 4 inches, power 115, exhibits a feature which, Fig. 21. so far as I am aware, has not been observed before, viz. a number of streaks parallel to the longest diameter of Plato, which Mr. Elger described as “ very 300 REPORT—1872. striking.” Ata still later period Mr. Neison observed Plato from 8.5 to 8.35. He described the floor as “ very dark,” and gave two gradations of shadow, that in the south-west being marked “ dark shadow,” while the portion be- yond, towards the east, he marked “shadow.” This portion is drawn as ex- tending nearly to spot No. 17, bisecting spot No. 1, and passing a little west of spot No. 16. On comparing the drawing with Mr. Elger’s at an earlier epoch, it would appear that Mr. Neison’s “ shadow ” was in some way con- nected withthe streakiness observed by Mr. Elger; for by 8.35 the true shadow must have retreated to about the position given by Mr. Neison for his “ dark shadow.” The outline also of Mr. Neison’s “ shadow ” is not in accordance with the peaks on the west border. Mr. Neison further deseribed the northern light-streak and sector as very distinct and of a pearl-grey colour, and spots Nos. 3 and 17 of a pale grey colour, which he saw di- stinctly. Spots Nos. 16 and 25 are described as “ faint.” ‘“ Although,” says Mr. Neison, “ this is extremely early, the spots were extremely plain.” Mr. Elger’s remark is as follows :—‘“ Sunrise finely seen; shadows of peaks y, 3, e very sharply defined ; no spots observed.” The darkness of the floor is alike recorded by myself and Mr. Neison; and Mr. Elger’s drawing testifies equally to it, especially on the north-east portion. It is this darkness, so unusual at sunrise, combined with the difficulty of making out the streaks and shadows on my part, and the observation by Mr. Elger of the peculiar streakiness, so unlike the ordinary light-streaks on the floor, that lead me to suspect that on the 20th of November, 1871, between 4.35 and 7.40 G. M. T., the interior of Plato was in an abnormal state. While the above-recorded observations were in progress, and the difficulty of observing the interior of Plato from 5.50 to 7.15 was very great, Mr. Pratt observed a very remarkable phenomenon on the Mare Frigoris, which he de- scribed as one of the most singular and striking of all the local observations he had witnessed. The following is an extract from his observing-book :— 5.30. Ona general survey of Plato and wide neighbourhood, the very pecu- liar aspect of the Mare Frigoris attracts attention. The appearance can be compared to nothing but a kind of haze, entirely local, hanging rownd the NV.W. foot of the slope of Plato. It is the more conspicuous as nothing of the kind is visible either on the Mare Imbrium or on the Mare Serenitatis. The objects on the Mare Frigoris were indistinct, as if veiled. At 6.30 the appearance was much modified. At 7.30 very little of the veiling was to be seen. Between other observations frequent attention was given to it until 9.0, but no return of the phenomenon appeared.” The contemporaneity of my own observations of the interior of Plato with those of Mr. Pratt of an immediate contiguous locality, is conclusive of the connexion between the abnormal condition of Plato and the veiled appearance of the N.W. slope, extending to the Mare Frigoris. On other occasions Mr. Pratt has described the appearance of the floor of Plato as if seen through a veil of thin white polarized clouds, such as appear in our own atmosphere. Phenomena of this kind are strikingly in contrast with an appearance which I witnessed on the same evening and at the same time,—it was the sharp and well-defined character of the broad band of roughened ground extending from the Apennines to the region of Ukert, Pallas, and Bode. Such observations as the foregoing remind one strongly of similar observa- tions recorded on numerous occasions by Schroéter, which are said by the greatest Selenographer of the present century to have been proved to have been illusions. It is a remarkable fact, and one well worthy of deep con- OBSERVATIONS OF LUNAR OBJECTS. 301 sideration, that whenever close attention is given to the moon’s surface some- thing of the kind is sure to crop up; nor is it confined to eye observations alone; photography tells the same tale. In the letterpress to the fourth area of the Lunar Map I have given instances of differences between photograms of various dates; and in drawing up my monogram of Hipparchus, I com- pared every object in every available photogram. It is much to be regretted that a means of detecting differences, if not changes on the moon’s surface, should be so little utilized, for I have not met with any published results of the comparison of lunar photograms except my own, as specified above ; and we know that numerous negatives must be in existence. We can hardly conceive it possible that illusion can enter as an element here; apparent dif- ferences may result from flaws either in the originals or in printing, but these are capable of being eliminated: and, again, on photograms we have whatever differences may present themselves under the eye; whereas in those observed with the telescope we have the records only to depend upon, and these records *will be more or less convincing according to the impression made by the phenomena on the mind at the time. As illustrative of this I quote Mr. Pratt’s remarks in connexion with the phenomena of November 20, 1871:— “Whether or no Lunar Meteorology ever becomes an accepted fact, I shall always retain a strong belief that this observation was one of the earliest and most complete records I know of, from the greatest intensity of the mist, or whatever it was that obscured the region, until its entire dissipation by the rays of the rising sun.” With this Mr. Pratt contrasts an observation of the Mare Frigoris on December 27, 1871, as follows :— Definition of objects on the Mare Frigoris fully as good as on any part of the border of Plato, in marked distinction to the observation of November 20, 1871.” One of the results of my late discussion of observations of the floor of Plato is, that certain peculiar phenomena, consisting of variations'of the brightness of the N.W. floor and in the forms of the streaks thereabout, have been noticed during the greater part of two years by two or more independent observers. On the 22nd of December, 1871, Mr. Pratt noticed “ a marked haziness over the north-west part of the floor of Plato, an instance of very limited mistiness.” Still, comparison with other portions of the floor rendered it to Mr. Pratt’s mind a no less certain instance than the former one of the Mare Frigoris ; for to one who has so constantly worked at the floor, even limited phenomena would be as apparent as those of wider range to the general observer. Now what are we to say to illusion? Here are independent observers during a period of many months testifying to the existence of the same phe- nomena; and not only so (for their testimony would have been weak had we merely taken a disjointed remark here or there, or had one observer only, as in the case of Schréter, recorded these seeings), but we have had the ob- servations carefully examined and arranged under certain heads, the evidence has been sifted, and we think that an impartial verdict would negative illu- sion, and declare for some active element producing the phenomena observed. What that element is becomes 4 most interesting question. So far as we have been able to make out, the most active agency that has modified the moon’s surface is voleanic. Have the appearances to which allusion has been _ made any connexion with a continuance of this agency ? 302 REPORT—1872. Report on the Mollusca of Europe compared with those of Eastern North America. By J. Gwyn Jerrreys, F.R.S. [A communication ordered by the General Committee to be printed zn extenso.] Arrer mentioning that he had dredged last autumn on the coast of New England in a steamer provided by the Government of the United States, and that he had inspected all the principal collections of Mollusca made in Eastern North America, the author compared the Mollusca of Europe with those of Massachusetts. He estimated the former to contain about 1000 species (viz. 200 land and freshwater, and 800 marine), and the latter to contain about 400 species (viz. 110 land and freshwater, and 290 marine); and he took Mr. Binney’s edition of the late Professor Gould’s ‘ Report on the Invertebrata of Massachusetts,’ published in 1870, as the standard of comparison. That work gives 401 species, of which Mr. Jeffreys considered 41 to be varieties and the young of other species, leaving 360 apparently distinct »species. About 40 species may be added to this number in consequence of the recent researches of Professor Verrill and Mr. Whiteaves on the coast of New Eng- land and in the Gulf of St. Lawrence. Mr. Jeffreys identified 173 out of the 360 Massachusetts species as European, viz. land and freshwater 39 (out of 110), and marine 134 (out of 250), the proportion in the former case being 28 per cent., and in the latter nearly 54 per cent.; and he produced a tabu- lated list of the species in support of his statement. He proposed to account for the distribution of the North-American Mollusca thus identified, by showing that the land and freshwater species had probably migrated from Europe to Canada through Northern Asia, and that most of the marine species must have been transported from the Arctic seas by Davis’s-Strait current southwards to Cape Cod, and the remainder from the Mediterranean and western coasts of the Atlantic by the Gulf-stream in a northerly direction. He renewed his objection to the term “ representative species.” The author concluded by expressing his gratitude for the kind hospitality and attention which he received from naturalists during his visit to North America last year. Mollusca of Eastern North America, according to Binney’s edition of Gould’s ‘Invertebrata of Massachusetts,’ eo 25 eal eg Page. Name of Species. 5 a S Synonyms and Remarks. Se aoe °° EI A ie 28 | Teredo navalis, Linné ......... N | Wood’s Hole, Mass. (J. G. J.). 29 Norvagica, Spengler ...) N E 30 |——megotara, Hanley ...... N E 31 |—— Thompsonii, Zryon...... 8 82 dilatata, Stimpson ...... N oe T. megotara, variety. 33 chlorotica, Gould (1870). N E | T. pedicellata, Quatrefages 84 | Xylotrya fimbriata, Jeffreys...) S (1849), var. 36 | Pholas costata, Z............h00 NS) 38 truncata, Say ............ 8 39 | Zirfeea crispata, J. ............ N E_ | Genus Pholas. 40 | Solen ensis) 7. ....c..c.ese0cs0es N EH 43 | Solecurtus gibbus, Sp. ......... 8 44 CTvASUS VSP, csactecec desc 8 ON THE MOLLUSCA OF EUROPE AND EASTERN NORTH AMERICA. 803 Name of Species. Machera squama, Blainville . costata, Say Solemya velum, Say (1822)... borealis, Zotten (1854) .. Panopza arctica, Lamarck (UIST) ec: Aa gra ec dd oe Ae CneCr ear Glycymeris siliqua, Chemnitz . Mya arenaria, L. ........2...+4 truncata, DL. .........06006. Corbula contracta, Say........- Nera pellucida, St............ Pandora trilineata, Say Lyonsia hyalina, Conrad...... arenosa, Moller Anatina papyracea, Say Cochlodesma Leanum, Conr.. Thracia Conradi, Couthouy GUESS) re. cet reco cnde stele aaah ws —— myopsis (Beck), Mail. (issn) yopsis (Beck) ae Mighels& Adams (1842). Mactra solidissima, Ch. See Serer rrr rr ovalis, Gould ........05- lateralis, Say ............ Cumingia tellinoides, Conr.... Ceronia arctata, Conr. ......... deaurata, Turton ......... Kellia planulata, S¢............. suborbicularis, Montagu. Turtonia minuta, Fabricius... Montacuta elevata, St... Saxicava rugosa, Pennant...... ATCUCHs Din. secseste otee ee Petricola pholadiformis, Lam. dactylus, Say ............ Macoma fusca, Say (1826) ... proxima, Gray (1839)... Tellina tenta, Say..........2.... tenera, Say Lucina filosa, S¢. (1851) dentata, Wood ............ Cryptodon Gouldii, Philippi (1845). Spherium simile, Say Cate. — partumeium, Say (1822) rhomboideum, Say ote Vermontanum, Prime (1861). truncatum, Linsley — tenue, Prime securis, Prime of Cape Cod. a ~S o > mM i] ° a ~ mS fo) Zi AAAs teens eeeeee tenes seneee seeeee Synonyms and Remarks. G. Siliqua. G. Siliqua. S. togata, young. S. togata, Poli (i791). Saxicava Norvegica, sp. (1793). G. Cyrtodaria. Allied to LZ. Norvegica. Allied to Thracia pretenuis, which is European. T. inflata, J. Sowerby (1845). T. truncata, Brown (1827). Not 7. truncata, Br. T. sep- tentrionalis, Jeffr. MS. Lovén received a single valve from Finmark. M. solidissima, var. Allied to M. subtruncata, which {is European. Mesodesma deauratum, var. G. Mesodesma. G. Lasea. G. Cyamium. Linné instead of Pennant. S. rugosa, var. Valentia, Ireland ; a fragment. P. pholadiformis, var. Tellina Balthica, L. (1766). T. calcaria, Ch. (1782). Allied to TJ. tenuzs. L. borealis, L. (1766). Axinus flecuosus, Mont., var. (1803). S. striatinum, Lam. (1818). S. lacustre, Miller (1774). Allied to S. cornewm, which is European. S. pisidioides, Gray (1856). Perhaps introduced into England. S. lacustre, var. S. lacustre, var. Rykholtit. 304 REPORT—1872. Name of Species. Spherium occidentale, Prime Pisidium dubium, Say (1816) Adamsii, Prime (1851)... — compressum, Prime...... —— equilaterale, Prime tenses ferrugineum, Prime...... abditum, Haldeman (1B41)........ccseeeeeereereeeee Astarte castanea, Say . sulcata, Da Costa ......... —— semisuleata, Leach (1817) —— quadrans, Gould elliptica, Hanley — Banksii, Leach (1817)... crebricostata, Forbes (1847 —— Portlandica, Mighels .... Gouldia mactracea, Linsley ... Cyprina Islandica, Z Cytherea convexa, Say......... Venus mercenaria, Z notata, Say Tapes fluctuosa, Gowld......... Gemma gemma, Totten Manhattensis, Prime ... Cardium Islandicum, JZ. ...... elegantulum (Beck), CTL BR Ssh onmatesner oa Bubrnss Liocardium Mortoni, Conr... Aphrodita Greenlandica, Ch. . Cardita borealis, Conr. (1836) rere e reer reer reer errr it twee ennee ter eeeeee sees wee eeeeeeereee Arca pexata, Say transversa, Say...........- Nucula tenuis, Mont. —— proxima, Say ............ expansa, Feeve ............ delphinodonta, Migh. ... Yoldia Tatil Say (1831)... — obesa, St. Peer eaters erecrees siliqua, Reeve (1855) ... —— thracixformis, Storer ... —— sapotilla, Gould (1841) . myalis, Cowth. ............ Leda tenuisulcata, Couth. (1838) — Jacksonii, Gould......... eee eee Cee $0 = ie) Be] 8 3 o a—h®) Q Ee 5 or EI a & N N EK N E N ING tices ° ING sseszee N H N SING Neves ce IN jesasésn N N 0 fe eco be NY us lteceas: N HK N E ING lhewees INN > il ace ese? N E ING aaees: N INE Siiessaeas N E IN} Alpena s N E N E INGS “ieee N E N E Ss IN) leeeees N EB N INES, | jceee a N Ez N E INS |/\deeeee N E N E N E aN OW cawatee N aD) INE: Sipeassacs Synonyms and Remarks. P. amnicum, Mill. (1774). P. fontinale, Draparnaud (1805). Allied to P. nitidum, which is European. P. pusillum, var. obtusale. P. pusillum, Gmelin (1788). Possibly some of these North- American species may be re- duced in number. Perhaps a variety of A. borea- lis, Ch. Including A. undata, Gould= A. Omalii, J. Sow. A, borealis, Ch. (1784), var. A. castaned, var. nana, A, sulcata, var. A, compressa, Mont.(1803),var. A. depressa, Br. (1827). A, compressa, var. G. Crassatella. G. Venus. V. mercenaria, var. Venus. V. mercenaria, young. G. Cardium. C. suleata, Bruguiére (1792), var. A, pexata, var. N. tenuis, var. Y. arctica, Sars. G. Leda. Allied to ce lucida, which is Europea L. aretiok: eas (1819). G. Leda. L. hyperborea, Lov. (1846). G. Leda. DL. pernula, Mill. (1770), var. L. pernula, var. ON THE MOLLUSCA OF EUROPE AND EASTERN NORTH AMERICA, Page Name of Species. 164 | Leda minuta, Fabr. ............ 165 caudata, Donovan.......+. 167 | Unio complanatus, Solander .. 169 nasutus, SA7/......1....e00 170 radiatus, Gi. .......ec00e 172 cariosus, Say .......0.0. 173 ochraceus, Say .....0...06 174 |Margaritana arcuata, Barnes LSZS) Rest. WS dees seeandses 176 | -—— undulata, Say .........6. 177 marginata, Gould......... 178 | Anodon fluviatilis, Zea......... 180 implicata, Say ....s....05 182 undulata, Say .........06 -183 | Mytilus edulis, Z................ 186 | Modiola modiolus, Z. ......... 188 | —— plicatula, Lam............. 190 | Modiolaria nigra, Gray ...... 192 GIGCORB Liseseecusoneangeaes 193, corrugata, St. .........6.- 194 |Crenella glandula, To¢z. ...... 195 pectinula, Gould (1841). 196 | Pecten tenuicostatus, Migh. § PAU Man ceeeretecst seca sca doseda. 198 Islandicus, Miill.......... 199 irradians, Lam. ....004.. 200 fuscus, Linsl. ............ 202 | Ostrea Virginiana, Lister...... 203 borealis, Lam. .......0000: 204 | Anomia ephippium, Z.......... 204 |—— aculeata, Gm. .........00. 205 electrica, D. ......ccccecees 206 squamula, D,....0..2...+0 208 | Terebratulina septentrionalis, Couth. (1839) eideessscecess< 210 | Rhynchonella psittacea, Gi. . 211 | Waldheimia cranium, Gm. ... 213 | Philine sinuata, Sf. ............ 213 | —— quadrata, 8. Wood....... 214 | —— lineolata, Couth. (1839) . 215 | Scaphander puncto-striatus, Migh. § Ad. (1842) .......4 216 | Diaphana hiemalis, Couth. ibe ptemcsstvacdiae.-2s-sscenen 216 | ——debilis, Gould (1840) ... 217 | Utriculus Gouldii, Couwth. SBN eee ties cn cn c:000sdeoseenne 218 pertenuis, Migh. ......... 219 | ——canaliculatus, Say ...... 220 | Cylichna alba, Br.........:....-. 221 | ——oryza, Tott. (1835) ....« | North or South of Cape Cod. European. & Hee ics) 30 Synonyms and Remarks. Mill. instead of Fabr. | L. minuta, var. Perhaps U. cariosus, var. Unio margaritifer, L. (1766). | G. Unio. G. Unio. Dillwyn (1817) instead of Lea. Anodonta cygnea, Li. (1766). G. Anodonta. A. cygnea, var. G. Anodonta. G. Mytilus. G. Mytilus. C. faba, Faby. (1780). P. irradians, young. O. -Virginiana, var. A. ephippium, var. A, ephippium, var. A. ephippium, young. Terebratula caput-ser pentis, Li. (1764), var. Miill., instead of Gm. rebratula. Allied to P. nitida, which is European. G. Te- P. lima, Br. (1827), S. librarius, Lov. (1846). Utriculusglobosus, Loy.(1846). Utriculus hyalinus, Turt. (1834). U. turritus, Moll. (1842). U. Gouldii, young. Bullautriculus,Brocchi(1814). x 5 306 REPORT—1872. ad Gs ; BBL Page Name of Species. — 2 Synonyms and Remarks. Bet 5 A 3 222 | Bulla incineta, Migh. ......... N 222 solitaria, Say ...,.......- S 223 |-— occulta, Migh. & Ad. (IBA) ase aesseceuetaeeneeneseSe N E | Cylichna striata, Br. (1827). 224 | Tornatella puncto-striata, dd) S | ...... Perhaps Act@on pusiilus. G, Acton. 226 | Polycera Lessonii, D’ Orbigny.| N E 228 | Doris bilamellata, L. ......... N E 229 tenella, Agassiz ......... iu wares Perhaps D. inconspicua, which is Huropean. 229 pallida, Ag. (1870) ...... N E_ | D. aspera, Alder & Hancock ; 1842). 230 diademata, 4g. (1870)...) N 1D) vo tuberculata, Cuvier (1802). 231 |—— planulata, SZ. (1853) ...) N E_ | D. repanda, A. & H. (1842). 232 PVISCAS Sip setea ste secnues: i eer “ Very closely allied to D, in- . conspicua.” : 233 | Ancula sulphurea, SZ. ......... it a ea “Very like to Ancula cristata,” which is European, 234 | Dendronotus arborescens, TET at oconPOPABEOORT CER: DFE N E 236 | Doto coronata, Ga. .........0.- N E 238 | Afolis papillosa, LZ. .......00.6. N E 240 salmonacea, De Kay (GSES Sastina in qaneten anneeee IN) Geades Folis bodoensis, Moll, (1842). 241 Bostoniensis, Cowth.......) N | ...... “ Approaching closely 2. coro- nata of Forbes,” which is European. 242 | —— rufibranchialis, Johnston.| N E 243 pilata, Gould ...,.......- N 245 | —— stellata, St. ..........0600- N 246 | —— purpurea, St. ...eecere eee N 246 Tey pe ao, 7s Aer N E 247 |—— diversa, Couth............- N 248 despecta, Johnst. ......... N E 249 | —— gymnota, De Kay......... IN) 3} agers “Nearly allied to #. concinna,” which is Kuropean. 250 | Calliopea (?) fuseata, Gould...) N 251 | Embletonia fuscata, Gould ...| N 252 remigatd, Gould ......... N 253 | Hermeea cruciata, 4lcx. Ag....| 8 254 | Aldevia Harvardicnsis, 4g ...| N 255 | Elysia chlorotica, Ag. ......... N 256 | Placobranchus catulus, 4g....| N 258 | Limapontia zonata, S¢..........] N 258 | Chiton apiculatus, Say......... 8 259 | —— cinereus, LZ. ......c0.00000- 8 E | GC. marginatus, not C, cinereus. Asingle specimen only ; ques- tionable. 260 |—— ruber, Lowe .........00.0e- N E 261 |——marmoreus, Far, ...... N h 263 albus, Mont... crctasvess oy SCC) epee CACC APO RES Buccinum undatum, L. ciliatum, Fabr..........06. Cobre ee eeeeseee —— Donovani, Gray (1839). cinereum, Say Fusus Islandicus, Gim.......... —— pygmaeus, St. ws... —— ventricosus, Gray tornatus, Gould: (i840) . decemcostatus, Say Trophon clathratus, L. seen eeeee —— scalariformis, Gouw/d (GUSSO) eyed sees sedet dowel ene muricatus, Mont.......... Busycon canaliculatum, L. . CATICa, G70. c.cccevccsoeess Fasciolaria ligata, Migh. § Ad. Ranella caudata, Say ......... Cerithiopsis Emersonii, Ad.... terebralis, Ad. (1841) ... Trichotropis borealis, Sow. ... Admete viridula, Fair.......... Vitrina limpida, Gould (1850) Hyalina cellaria, Miéll.......... arborea, Sai/........sss0e0 electrina, Gould (1841). indentata, Say .......0.+ minuscula, Binney —— Binneyana, Morse —— milium, Morse ferrea, Morse..........0.00 — chersina, Say (1821) . — minutissima, Lea ( (i841) —— multidentata, Binney . lineata, Say Macrocyclis concava, Say...... Limax maximus, L. ...........- agrestis, L. campestris, Binney (1841) tenes North or South of Cape Cod. N N res| | European. leoitc>| loco) Synonyms and Remarks. C. Holbillii (Beck), Mall. (1842). | Subgenus Desmoulea. | NV. propingua, J. Sow. (1824). Not that species, but B. un- dulatum, Moll. B.g glaciale, L. (1766). G. Urosalpinz, allied to Pur- pura. Not that species, but /’. curtus, Jeffr. Not Buccinum Sabinti or Fu- sus Sabini, Gray. F. despectus, Li. (1766). Not that species, but 7. trun- catus, Str. T. clathratus, L. (1766). Doubtful as American, G. Cerithium, not Cerithiopsis. C. trilineata, Ph. (1886). Broderip and Sowerby’s spe- cies. V. pellucida, Mill. (1774). G. Zonites. Closely allied to Z. excavatus, but umbilicus much less open. Zonites radiatulus, Alder (1880), var. alba. Zonites fulvus, Mull. (1774). Helix pygmea, Drap. (1805). L. levis, Mill. (1774). OE 309 310 Page. 410 412 413 415 415 417 418 420 422 423 424 425 426 427 428 429 431 433 433 434 435 456 437 438 439 39 440 441 442 442 445 444 445 446 447 448 45] 453 454 454 457 465 466 467 471 473 REPORT—1872, Sr 3g ae ‘ 3 Name of Species. ca ey Bos 68 39 E A & Diam tlayie 2, geateenceceacscd N E | Helix alternata, Say ............) N striatella, Anthony ...... N asteriscus, Morse ......... N labyrinthica, Say......... N hirsuta, Say .........s0-..- N — monodon, Rackett ...... N palliata, Say.........e000.. N tridentata, Say...........- N albolabris, Say............ N — dentifera, Binn. ......... N —— thyroides, Say ............ N SAV, BOR ses.s.0eceroee N —— Pharpa, Say ..eceecccceeeee N E pulchella, Miill. ......... N E —— hortensis, Mill. (1774)..| N E Cionella subcylindrica, Z....... N iE Pupa muscorum, Ly .......00. N E — Hoppii, Moll. .......... N pentodon, Sa7 ..........4. N decora, Gould .........00 N Falla Si ieaddcwsassth as. 8 armifera, Say ...........- = aN, — contracta, Say ...........- N Tupicola; Say. ..c..0s0006s N corticaria, Say .......6..4. N Vertigo Gouldii, Binz. (1843)| N E milium, Gould............ N Bollesiana, Morse (1865)| N E ovata, Say (1822) ...... N iH —— ventricosa, Morse(1865).) N E simplex, Gould (1840)...| N E Succinea ovalis, Gould (1841).| WN aS) avara, SAY. ccsceicsssceeee- i ROY er obliqua, Say (1824)......] N E Totteniana, Lea ......... mM | Case: Arion fuseus, Mill, (1774) ...) N 10) Zonites inornata, Say ......... ON acdeees suppressa, Sa7............ N — fuliginosa, Griffith ...... N Tebennophorus dorsalis, Binn.| N Alexia myosotis, Drap.......... N E Carychium exiguum, Say (VS Z 2) rites cca sertaghetnn 13 ; 8 1S LIMULUS wu] [= Jurassic. a he ee 3 ‘ S R & eS i | | ee | a § "3 SI || ome ee 3 ty |* eee 8S: 3 Ss ; 2 2 = Triassic. ge S Si9 She SS 5 = xa) i) 8 S = Hs-es hss 12 Ug Sy ae Sis ae sl g/g Sigs S Permian. ax oS Ss & | s Fs + = “|= og BY _*Ss te | ES ~SS—|+BELLINURUS —|— S35 rr id 18 = PRESTWICHA yg 23 J feoscoRPis Carboniferous. a mS z ref = 4 gS fi it xz ao < =z —, — Es ——B— 3 -?-5. [i é E Dep ie Devonian. ma 3 ry a eg fee -wS_E__ is ea Rs : 3 é "SE NEOLIMULUS 5 oe Explanation of Lines. Upper Silurian. | fy 3 rs i] es ia Ejeeesmro Aberrant and parasitic types. 2a sa OX Ea Fy ieee ty, 3 3 - By Fi ? oi hw] = Groups which possessed both per- Fe pait i] s a # os sistence and powers of modifica- Lower Silurian. ime 5 A z ee roll tion and development. 2 Re a: Persistent types with little or no , cd i paweste nnn variation. Upper Cambrian. CN So rt? veeenne. Groups which have died out. EEE eS ee med {a Pao 1-2): Probable common point of ancestral ON THE SOLAR ECLIPSE OF DEC. 12, 1871. 327 The accompanying Table (p. 326) is merely intended as an attempt roughly to indicate (according to our present knowledge of the earliest appearance in time of the several orders of Crustacea) the most probable manner in which the various groups were evolved from a common pre-Cambrian parent-stock. I have specially distinguished those which are merely persistent types, but incapable of modification, from those which were capable both of persistence and modification ; and these again from the inadaptive types which have died out. The aberrant and highly specialized parasitic types appear last in time, and mark the culminating point of the Crustacea when conditions prevailed more highly favourable to the class than at any earlier period. Report of the Committee appointed to organize an Expedition for observing the Solar Eclipse of Dec. 12, 1871. Ar their Meeting in Edinburgh in August last, the General Committee of the British Association for the Advancement of Science having had under their consideration the great importance of observing the eclipse of 12th of De- cember, 1871, authorized their President, Sir W. Thomson, F.R.S., to bring the matter to the notice of the l'reasury, which he did in a letter dated 9th August, 1871, stating fully how desirable it was in the interest of science that advantage should be taken of this opportunity to advance solar physics, and explaining in general terms the best methods of carrying them out. It was suggested in the President’s letter that Mr. J. Norman Lockyer, F.R.S., who had long devoted himself to spectroscopic investigations, should form a member of the expedition. The President was authorized by Sir E. Sabine, K.C.B., President of the Royal Society, and Mr. Lassell, President of the Royal Astronomical Society, to state to the Treasury their cordial concurrence in the request of the British Association. ; A most prompt reply was received to their communication, the Treasury, by a letter dated 16th August, 1871, acceding at once to the request of the President, and granting a sum not exceeding £2000 for the purpose. In the hope of a favourable reply being received from the Treasury, the General Committee had, by a resolution at their last Meeting in Edinburgh, authorized the General Officers to take such steps as they might deem advisable as soon as possible after the receipt of the Treasury letter. The General Officers held a meeting on the 22nd of August; and having in the first Mmstance requested Mr. Norman Lockyer, F.R.S., to join them in consulta- tion, they resolved to appoint a Committee to direct all the necessary arrangements. To this Committee, as originally constituted, additional members were from time to time added. It now consists of the following names :—The President and General Officers of the Association, Prof. J. C. Adams, Sir G. B. Airy (Astronomer Royal), Prof. Clifton, Mr. De La Rue, Dr. Frankland, Mr. Hind, Mr. -Lassell (President R.A.S.), Lord Lindsay, Mr. Lockyer, General Sabine, General Strachey, Colonel Strange, and Prof. Stokes. The Treasury having been good enough to address the Admiralty and the War Office requesting their cooperation, the Committee entered into com- 328 REPORT—1872. munication with these departments and with the Colonial and Indian Officers, and have much pleasure in stating that they haye had the most liberal and hearty assistance from all the departments of Government. The first duty of the Committee was to arrange for the dispatch of instru- ments and instructions to Australia, which it was necessary to do by the mail of the 2nd of October. By Mr. Lockyer’s exertions, and the kindness of Mr. Huggins in making over a camera of Mr. Dallmeyer’s, which the Committee undertook to replace within a month, these instruments were all sent off in good time, and reached Melbourne with little or no damage. The unfortunate result of the expedition to Australia, from bad weather, -is well known and deeply regretted, and need only be briefly mentioned. The Committee now turned their attention to the selection of the places best adapted to observation in India. Very careful inquiries were made from every available source as to the nature of the climate in different parts of India on the 12th of December, and in these the Committee received most valuable assistance from General Strachey. The season was about the middle of the north-east monsoon, making it probable that there would be fine weather on the west coast of the peninsula, but that the weather on the east coast and in Ceylon could not be depended upon, the rainy season breaking up in December, but sometimes early in the month, but at other times not till nearly or quite the end. It was originally intended to fix the number of observers at five; but on further consideration it appeared to the Committeé that, because of this un- certainty of weather, it was desirable to divide the expedition into as many parties as possible; with the very important assistance mentioned in the next paragraphs, they were of opinion that it would be feasible, by means of the Treasury grant, to purchase the necessary instruments and to provide passage-money for ten observers. The Peninsular and Oriental Company, at the request of the Committee, made the most liberal arrangements for freight and passage to and from Point de Galle, and the Admiralty at once communicated by telegraph with Admiral Cockburn, at Trincomalee, receiving an immediate reply, stating the frigate ‘Glasgow ’ would be at Galle on the 25th of November in readiness to trans- port the party to the place of observation and bring them back again. The Governor of Ceylon, in the same liberal manner, not only placed the steamer ‘Serendib’ at the disposal of the expedition, but undertook to give all possible assistance in officers and material which might be needed. After making these arrangements, the Committee appointed Mr. Lockyer chief of the expedition, and Dr. T. Thomson Secretary and Treasurer. The selection of observers was necessarily difficult. To many highly qua- lified physicists the length of the voyage was an insuperable obstacle; but Mr. Lockyer was able to submit to the Committee the following names :— 1, Rey. R. Abbay, Wadham College, Oxford; 2. H. Davis, Esq.; 3. R. J. Friswell, Esq.; 4. Henry Holiday, Esq.; 5. W. Lewis, Esq.; 6. Captain Maclear, R.N.; 7. H. N. Moseley, Esq.; 8. Captain Tupman, R.M.A.—all gentlemen devoted to and well skilled in solar physics. To the chief of the expedition and to these gentlemen the Committee have great pleasure in giving their most cordial thanks for the zeal which led them to undertake a long voyage with the sole object of the advancement of science, and in expressing their great satisfaction with the way in which the expe- dition was carried out. Mr. Davis, the accomplished photographer of Lord Lindsay, undertook the ON THE SOLAR ECLIPSE oF DEC. 12, 1871. 329 department of Photography ; and the Committee have to express their sense of the generous assistance afforded them by that nobleman in supplying all the necessary photographic apparatus. Mr. Holiday, a skilful artist, who had long been a student of physical science, undertook to sketch the phenomena of the eclipse. To the other gentlemen the spectroscopic and polariscopic observations were allotted under the direction of Mr. Lockyer. Before leaving England Mr. Lockyer telegraphed and wrote to Signor Respighi, a very eminent Italian astronomer, requesting him to join the party, which, by the liberality of the Italian Government, he was able to do, joining at Suez, and rendering most valuable assistance. Mr. Lockyer tried further to obtain the assistance of several very distin- guished foreign observers. He communicated with Mr. Young, M. Janssen, M. Zéllner, M. Angstrém, Prof. Schmidt, and Mr. Peise; but from various causes none of these gentlemen could join the party. The expedition embarked at Southampton on the steamer ‘ Mirzapore,’ receiving early attention and assistance from Captain Paris, R.N.R., and the officers of that ship, which was selected on account of its passing through the Suez Canal, so that all risk of injury to the instruments was avoided. The party reached Galle on the 27th of November, fifteen days before the day of the eclipse. Subject to any alteration which might become needful on the receipt of more complete information in Ceylon, Mr. Lockyer had made the following arrangements of stations and observers :— Ceylon. Trincomalee: Mr. Moseley. Jaffna: Mr. Lewis, Captain Tupman, R.M.A. India. Poodoocotta, near Trichinopoly: Signor Respighi, Mr. Holiday. Mannatoddy, in Wynaad: Rev. Mr. Abbay, Mr. Friswell. Baikul, in Canara: Mr. Lockyer, Mr. Davis, Captain Maclear, Dr. Thomson. The Ceylon party embarked at once on the ‘Serendib,’ where they were received by Captain Fyers, R.E., the Surveyor-General of Ceylon, and Captain Hogg, R.E., who had been requested by the Ceylon Government to assist the expedition, and both of whom furnished very valuable reports. The other parties embarked on board the frigate ‘Glasgow,’ whence the Poodoocotta party was landed at Beypore, the Wynaad party at Cannanore, and the Canara party at Baikul. The Committee are happy to state that the weather was favourable, and the observations successful at all the stations but one. At Mannatoddy, in Wynaad, the sun was obscured, and the regret with which the Committee learned the bad luck of Messrs. Abbay and Friswell was enhanced by their knowledge that the land journey of these observers was one of great hardship and fatigue. The Committee are most anxious to take this opportunity of stating that the expedition received every possible assistance from the Viceroy and ° Governor-General, the late Lord Mayo, from the Governor of Madras, Lord Napier, and from the Governor of Ceylon, Sir Hercules Robinson, and from all the officials of both the Indian and Colonial Governments with whom they came in contact. They have further to report that the frigate ‘ Glasgow’ not having been able, owing to its services being urgently required elsewhere, to bring the parties back to Galle and Bombay, the Government of Madras was good enough to assist the expedition, which would otherwise have been in diffi- 330 REPORT—1872. culties as to travelling expenses from the places of observation to Galle or Bombay, by a liberal grant of £100. In conclusion the Committee have much pleasure in laying before Section A an interim report by Mr. Lockyer on the results of the expedition, to be fol- lowed as soon as possible by the full report, which the Royal Astronomical Society have undertaken to publish. An interim Report on the Results obtained by the British-Association Eclipse Expedition of 1871. By J. Norman Locxysr, F.R.S. I. New Instruments. These were as follows :— 1. A train of five prisms to view the corona. 2. A large prism of small angle placed before the object-glass of a telescope. On these instruments I may remark that the Royal Astronomical Society, in the first instance, invited me to take charge of an Expedition to India merely to conduct spectroscopic observations; but although this request did me infinite honour, I declined it, because the spectroscope alone, as it had been used before, was, in my opinion, not competent to deal with all the questions now under discussion. Thus some of the most eminent American observers had come to the conclusion that the spectrum of hydrogen observed in the last eclipse round the sun, to a height of 8’, was a spectrum of hydrogen ‘‘far above any possible hydrogen” at the sun. Hence it was in some way reflected. Now with our ordinary spectroscopic methods it was extremely difficult, and one might say impossible, to determine whether the light which the spectroscope analyzed was really reflected or not; and that was the whole question. It became necessary, therefore, in order to give any approach to hopeful- ness, to proceed in a somewhat different way in the 1871 expedition, with regard to the spectroscope, and, to guard against failure, to supplement such observations with photographs. To understand the method adopted, let us suppose a train of prisms. Take one prism out of the train, and consider what will happen if we illuminate a slit with a monochromatic light and observe it through the prism. If we render sodium vapour incandescent and illuminate the slit by means of it, we get a bright yellow image of the slit, due to the vapour of the metallic sodium only giving us yellow light. But why is it that we get a line? Because we employ a line slit. If, instead of a straight line, we have a crooked line for the slit, then we see a crooked line through the prism. Going one step further : suppose that instead of a line, whether straight or crooked, we have a slit in the shape of a ring, we see a ring image through the prism. And then comes this point: if, when we work in the laboratory, we examine these various slits, illuminated by these various vapours, if we observe the corona in the same way, we shall get a ring built up by each ray of light which the corona gives to us, since we know, from the American observations, that there were bright lines in the spectrum of the corona as observed by a line slit; in other words, the corona examined by means of a long train of prisms should give us an image of itself painted by each ray which the corona is competent to radiate towards us*. These were the considerations which led to the adoption of this new attempt to investigate the nature of the corona now in question. It was, to use a * After I had thought of this arrangement, and had secured an instrument to carry it out, Prof. Young, in a communication to ‘Nature,’ suggested the same method of observation. ON THE SOLAR ECLIPSE OF DEC. 12, 1871. 331 train of prisms, pure and simple, using the corona as the slit, a large number of prisms being necessary to separate the various rings we hoped to see, by reason of their strong dispersion. This principle, good for a train of prisms such as I have referred to, is good also for a single prism in front of the object-glass of a telescope. Such was the method adopted by Prof. Respighi, the distinguished Director of the Observatory of the Capitol of Rome, who accompanied the expedition. This method, if it succeeded, would be superior to the ordinary one in this way. If we were dealing merely with scattered light, then all the rings formed by vapours of equal brilliancy at the base of the chromosphere would be of the same height; while if such scattering were not at work, the rings would vary according to the actual height of the vapours in the sun’s atmosphere. 3. Integrating spectroscopes driven by clockwork. 4. A self-registering integrating spectroscope, furnished with telescopes and collimators of large aperture and large prisms. (This instrument was lent by Lord Lindsay.) 5. A polariscope-telescope so arranged that the same observer could almost simultaneously observe both with the Savart and the Biquartz. 6. A polariscope-telescope arranged for rapid sweeping round the corona at a given distance from moon’s limb. Tl. Tur Mar Resvrts. Spectroscopic Observations. It has been established that the idea that we do not get hydrogen above 10” above the sun is erroneous, for we obtained evidence that hydrogen exists to a height of 8’ or 10’ at least above the sun. Just as the sun disappeared Prof. Respighi employed the instrument to which I have already referred to determine the materials of which the pro- minences which were then being eclipsed were composed; and he got the prominences shaped out in red, yellow, and in violet light, a background of impure spectrum filling the field; and then as the moon swept over those prominences they became invisible. He saw the impure spectrum and the yellow and violet rings gradually die out, and then three broad rings, painted in red, green, and blue, gradually form in the field of view of his instrument ; and as long as the more brilliant prominences on both sides of the sun were invisible he saw these magnificent rings. These rings were formed by C and F, which show us that hydrogen extends at least 7’ high ; for had we been dealing with mere glare, had we not been dealing with hydrogen itself, we should have got a yellow ring as well. In addition to the red ring and the blue and violet, which indicate the spectrum of hydrogen, he saw a bright green ring, much more’brilliant than the others due to 1474. While Prof. Respighi was observing these rings by means of a single prism and a telescope of some 4 inches aperture, some 300 miles away from him (he was at Poodocottah and I was at Bekul) I had arranged the train of five prisms. My observation was made intermediately, as it were, between the two observations of Prof, Respighi’s. The observations may be thus compared :— Respighi .. C D? FG .... Prominence at beginning of eclipse. Lockyer ..C 1474 FG.... Corona 80" after beginning of totality. Respighi.. C 1474F_ .... Corona mid eclipse. 332 REPORT—1872. I had no object-glass to collect light, but I had more prisms to disperse it, so that with me the rings were not so high as those observed by Respighi, because I had not so much light to work with ; but, such as they were, I saw them better, because the continuous spectrum was more dispersed, and the rings (the images of the corona) therefore did not overlap. Hence doubt- less Respighi missed the violet ring which I saw; but both that and 1474 were very dim, while © shot out with marvellous brilliancy, and D* was absent. These observations thus tend to show, therefore, that instead of the element the line of which corresponds with 1474 existing alone just above the pro- minences, the hydrogen accompanies it to what may be termed a great height above the more intensely heated lower levels of the chromosphere, including the prominences, in which the lower vapours are thrown to a greater height. With a spectroscope of small dispersion attached to the largest mirror of smallest focus which I could obtain in England, the gaseous nature of the spectrum, as indicated by its structure (that is, bands of light and darker intervals as distinguished from a continuous spectrum properly so called), was also rendered evident. Photographs and Structure of Corona. The photographic operations (part of the expense of which was borne by Lord Lindsay) were most satisfactory, and the solar corona was photographed to a greater height than it was observed by the spectroscope, and with details which were not observed in the spectroscope. Mr. Davis was fortunate enough to obtain five photographs of great perfection at Bekul, and Captain Hogg obtained some at Jaffna ; but the latter lack in detail. The solar nature of most, if not all, of the corona recorded on the plates is established by the fact that the plates, taken in different places, and both at the beginning and end of totality, closely resemble each other; and much of the exterior detailed structure is a continuation of that observed in the inner portion, independently determined by the spectroscope to belong to the sun. This structure I was also enabled to observe in my 63-inch equatorial, even three minutes after totality was over ; and we may now say that we know all about the corona, so far as the structure of its lower brighter levels (that portion, namely, which time out of mind has been observed both before and after totality) is concerned. It may be defined as consisting of cool promi- nences—that is to say, in this region of the corona we will find the same appearances as in prominences, minus the brightness. We find the delicate thread-like filaments which all are now so familiar with in prominences ; the cloudy light masses, the mottling, the nebulous structure, all are abso- lutely produced in the corona ; and I may add that the fainter portion of the ring, some 5’ round the sun, reminded me forcibly in parts of the nebula of Orion and that surrounding 7» Argus, as depicted by Sir John Herschel in his Cape observations. While both in the prism and the 63-inch equatorial the corona seemed to form pretty regular rings round the dark moon, of different heights, according to the amount of light utilized by the instrument, on the photographic plates the corona (which, as I have before stated, exceeds the limits actually seen in the instrument I have named) has very irregular (ignored by the spectroscope), somewhat stellate poles—-a fact perhaps connected with the other fact, that the most active and most brilliant prominences rarely occur there. ON THE SOLAR ECLIPSE OF DEC. 12, 1871. 333 Sketches. From the photographs, in which the corona is depicted actinically, we pass to the drawings, in which it is depicted visually. I would first call attention to two drawings made by Mr. Holiday, who formed part of the expedition, and in whose eye every one who knows him will have every confidence. First, there is a drawing made at the commencement of the totality, and then a drawing made at the end. There is a wonderful difference between these drawings; the corona is in them much more extensive than it is repre- sented actinically on our plates. In another drawing, made by Captain Tupman, we have something abso- lutely different from the photographs and from Mr. Holiday’s sketches, inas- much as we get an infinite number of dark lines and a greater extension than in the photographs, though in the main the shape of the actinic corona is shown. The corona, as it appeared to me, was nothing but an assemblage of such bright and dark lines; it lacked all the structure of the photographs, and appeared larger; and I have asked myself whether these lines do not in some way depend on the size of the telescope or the absence of a telescope. It seems as if observations of the corona with the naked eye, or with a telescope of small power, may give us such lines; but that when we use a telescope of large power it will give, close to the moon, the structure to which I have referred, and abolish the exterior structure altogether, leaving a ring round the dark body of the moon, such as Prof. Respighi and myself saw in our trains of prisms, and I in the 63-inch telescope, in which the light was reduced by high magnification so as to bring the corona to a definite ring some 5’ high, while Prof. Respighi, using a 4-inch telescope, brought the corona down to a ring something lke 7’ high. Many instances of changing rays, like those seen by Plantamour in 1860, were recorded by observers in whom I have every confidence, one observer noting that the rays.revolved and disappeared over the rifts. Polariscopie Observations. Mr. Lewis, in sweeping round the corona at a distance of some 6’ or 7' from the sun’s limb, using a pair of compensating quartz wedges as an analyzer, which remained parallel to itself when the telescope swept round, observed the bands gradually to change in intensity, then disappear, bands of a com- plementary character afterwards appearing, thereby indicating radial polari- zation. Dr. Thomson, at Bekul, saw strong traces of atmospheric, but none of radial polarization, with a Savart. With the same class of instrument the result obtained by myself was precisely similar; while on turning in the Biquartz, at the top and bottom of the image of the corona, 7. ¢. near the sun’s equator, faint traces of radial polarization were perceptible for a short distance from the moon’s limb. Captain Tupman, who observed with the polariscope after totality, announces strong radial polarization extending to a very considerable distance from the dark moon. Reversal of Lines at beginning and end of Totality. Captain Maclear, who was observing with me at Bekul for some time just before the commencement of totality, but when the light of our atmosphere was cut off by the interposition of the dark moon, saw a large number of very fine lines of different heights at the base of the chromosphere. 334 REPORT—1872, Mr. Pringle, also at Bekul, saw many lines flash into the field of an analyzing spectroscope, carried by clockwork, at the end of totality. Captain Fyers, the Surveyor-General of Ceylon, observing with an inte- grating spectroscope, saw something like a reversal of all the lines at the beginning, but nothing of the kind at the end. Mr. Fergusson, observing with an instrument of the same kind, saw reversal neither at the beginning nor the end, though during totality he saw more lines than Captain Fyers. Mr. Moseley states that at the beginning of the eclipse he did not see this reversal of lines. Whether it was visible at the end he could not tell, because at the close the slit had travelled off the edge of the moon. Prof. Respighi, using no slit whatever, and being under the best conditions for seeing the reversal of the lines, certainly did not see it at the beginning ; but he considers he saw it at the end, though about this he is doubtful. From the foregoing general statement of the observations made on the eclipse of last year, it will be seen that knowledge has been very greatly advanced, and that most important data have been obtained to aid in the discussion of former observations. Further, many of the questions raised by the recent observations make it imperatively necessary that future eclipses should be carefully observed, as periodic changes in the corona may then possibly be found to occur. In these observations the instruments above described should be considered normal, and they should be added to as much as possible. Preliminary Report of a Committee, consisting of Professor M1cuart Foster, F.R.S., Professor W. H. Frowrn, F.R.S., and BensaMin Lownz, M.R.C.S., appointed for the purpose of making Terato- embryological Inquiries. Mr. Lowne reported on two forms of Incubators. He thought from his experiments that to insure success the heat must be applied above the egg, and that the death of all those which he placed in an incubator heated beneath was due to convection. Death took place in all these cases from rupture of the yelk-vessels between the third and tenth day. Other deficiencies were observed in many embryos; but owing to the im- perfect condition of the incubators in use, Mr. Lowne was not sufficiently satisfied as to their nature. Mr. Lowne believed he had adopted a plan of incubator, in which the temperature is regulated by an air-thermometer and the heat is applied aboye, which would enable him to arrive at satisfactory results in the course of next year. ON ELLIPTIC AND HYPERELLIPTIC FUNCTIONS. 335 Report on Recent Progress in Elliptic and Hyperelliptic Functions. By W. H. L. Russext, F.R.S, WE now enter on the consideration of the Hyperelliptic Functions. I propose to divide the subject into four parts, thus :— Part I. On the System of Hyperelliptic Differential Equations adopted by Dr. Weierstrass. Part IT. On the System of Hyperelliptic Differential Equations adopted by ____ Jacobi, Gépel, and Rosenhain. ; Part III. On the Transformation of Hyperelliptic Functions. I hope to add Part IV. On certain Theorems not involving the Periods of the Functions, with a Supplement to the Report. al Parr I. On the System of Hyperelliptic Differential Equations adopted by Dr. Weverstrass. We now proceed to explain the discoveries of Dr. Weierstrass. It will be seen that the form of his hyperelliptic differential equations is different from that assumed by Jacobi, Gépel, and Rosenhain. The object of Weierstrass is to solve these equations; and the advantage of his method will be seen when we consider that he solves the hyperelliptic equations generally, and not for ‘a particular case, which is all that Gopel and Rosenhain had previously effected. Weierstrass assumes as follows (Crelle, 47) :— me (2) de P(x) dx “n P(x) dee bof 22 fiat (20 gt tf" 22 ae 2n—1 me * P(x) da 2 P(w) da *n PCa) da B-{ 22% 2VR(@) + vag tf a WIG G9n—1 &e.=c&e. ‘ ={ "26 ae Re ae a ee i; ae —%n-1 2V R(x) | ae =e ay, 2 aan AV R() where R(a)=(# —a,)(«@—a,)(*% —a,) ore (w—a,,); P(~)=(x—a,)(# —a,)....(*#—4a5,_}) 3 and let Q(x) =(«#—a,)\(w—a,)....(@—4ay,), so that R(x) =P(aw) . Q(a). Ef L(e) = («—2#,)(#—«#,)....(v—a,), we define _ M(-1)4L@,) V(-1yBG) where a is the greatest number contained in 3a ; al (uu... + -Un)y sn et el 336 REPORT—1872. also al(u,u,..- Un)a, p= VA + (a,— 4%) TE VR(x,) a (uu, - ++ Uy) gt (uu, cia B (w,—a,)(@,—a,) L'(z,) where the upper or lower sign is to be taken according as a is less or greater than 3, and where & refers to y, ANG yee Soke ua Ie a eo) P(a)da Now let i-\ sey VR(@)* then 5 1 2 2Qv K,—K,+K,—....+K,=0, for v=1, 2,3....n. (See Jacobi, Crelle, 13.) Moreover, let 2-1 2 oe P(a)da ' 2(w—ay,_1) V R(@) 1 pee me eeB Berl (%2c-1 P(x)da F pei 2(v@—dy,_) VR(ax) . K,=K, ,+K,o+ Kw K =K, i+K, 2+ K, .—?K,, 1, Kok 4K 44 K, ,—?K, » K,=K, + +K,,,—?K,, 1 — 7K, » K=K, .+ +K,,,,—1K,, ,—iK,, »» 2 a taiad , Kink, 4K, 5— eK, 5 then the following four fundamental formule hold good, where we make use of the symbol (/a to denote zero when ais less than #, and unity when « is greater than 3 :— qa 24 al(u,+K, ae are ).= al(u,w,...+)a. . . . . . . (1) ga 7a al(u,u,...-), Ces eae re Fe P/aal(u,,U,. +» Phen (2) ft VOR oy akon ae B —#/"al(u,.... al(u,—K,....) = ae al(u,..++)g B al(u, +K ON ELLIPTIC AND HYPERELLIPTIC FUNCTIONS. 337 We shall now indicate the method by which these formule are to be . proved; it will be sufficient if we put n=3, which will guide at once to the investigation for (7) greater than 3. Let (w—a,)(w—a,)(x—a,)(w—p)"(x—g)"(e@—1)— (2—a,)(w—a, )(¥—4,)(@—4,)(C, +00 + 60°) = (w@—w,')(e—x,)(u—a,)(w—x,")(a—a")(w—a",)(w—a,)(@—#,)(€—#,),(3) ~ and put in this equation which also necessitates : P=4,, I=, T=A,, and the equation becomes (a—4a,)(x—a,)(a— a, )(w—a,)(x—a,)(v—4,) —(#— A, )(C, + Oe+ ©,cv*) =(a«—a',)(w—z2',)(w—x', (w—w,)(w—a,)(w—a,).. » » » « CA) Putting in this equation successively v=, v=a,, #,=x,, we have V Re Co+6,2,+6,0,°= V v,—a, V Re C+6,0, 16,0, = 25 wv, — a, VW Re C,+6,0,+ C0, + v Re, : v,— a, whence a VA Re, : Lt. v,— 4a, (a, =F X,)(%, i x,) nm VA Ra, : Li, VA Re, : v0, v,— a, (a, a Ly )(X, a #,) v,— Me (w, iy x, )(@, Te ,) pert: V Re, ‘ U+2, v,—a, (2, ea? L,)(X, - 2,) _ WRa; Ui +2, WV Re, Ui +x, ° —= ——————— v,— a, (2, < &,)(L, = x,) v,— a, (a, an L,)(X, Sale ) ow VRe, 1 V Re, 1 : v,— a, (7,— X,)( x, mi x,) v,— Mb, (a, i x), aa v,) V Re 1 L,—U, (L,—%,)(%, — 5) Substitute these values in equation (4), and we have, putting at the same time v=a,, V {(a,—#' (Gq — #4 — EV 1G — 2 (4, — 2. )(G, — #4) =4iVa,—4, { ptm,K anor +m,K rr w= 7K tb Ky atin + 7K, gy e,=m,J, +m eg marie Fass Gt gat) at sb Ted then we shall have Alfa De Rr ae OT? Pa). Ala Dw'.bos oan Tee he CAl(ue.).. « We shall prove the first of these formule. We easily deduce from equation (1), section 5, that AG, LOK Seo Ae CAO where m is an integer. Hence a B Al(u,+ 2mK, + 2rK,....)= 23 mI,(u,+2rK,-+K,) —23,r5,(u, brik eae ad ine ve ae YAl(u. eas) j a Bp Ad, $rd,)(u,-+rk, -+mK,) +mr(K, —KWbaiu....) a ae B a. — Send Nt EE I nas esi) 5 ON ELLIPTIC AND HYPERELLIPTIC FUNCTIONS. B45 In precisely the same manner we shall find, continuing ‘the process, a B Y Al(u,+ 2mK, + 2rK, + 28K, . Fe «i)} a B a _.-28,f(nd, tr, +08, cu, bi, 0K, +0h,) By ay a B a as 4 ms(J,K,— 5K) +as(J,K,— K,J,) } AlGies. 48.) a B a B NY _ ool (m3, +05,+85,)(u,-+mK,+rK,+sK,)} ies, from which we may infer the truth of the theorem. Section 8.—Now assume 1 “= 7 (K, v,+K,, gat eee +K, Un), 1 u= ~ (Kz, M+ Ky wt...» + Ke, Yn), = +, 1, +K,, 0,+ ae +K 10m) ; whence we obtain equations of the form v,=7(G,, 1, + Ge, Wat... +G,, Mn)» v,=7(Gy, gu, + Ge, Ua... +G,, WUn)> v,= 1 (Gy,,t, + Ge,,U,# ey 'Sie 8 4+Gy, Mn) > from these equations we have manifestly voV;,e” Vs; =X, cGy, c= 0, = K G. =O. . voc 2K, .G,.=1, >%%,,6,.=1, (B) Then from the first of equations (2), section 6, we have 2(G,, 0K, Jy, 0 Gy, oy, Ky, 0) =0, or 2{K,, 3.6), 03,,0—J,, 2eGy, oK,, o} =0, or Se, het an a, SAK eG peda dee Boe, My, tdi But BAR 3.6. dig —t coCuela) es, 2 Gt i ee at =JS,.—-Iy, 93 34.6 ° REPORT—1872, consequently we shall have . 2,1K,, oze(Gy, ol, yc Jie G, = =0. This equation must hold good for all values of ¢; wherefore, putting pHre(Gy, od v,¢c Jy, ec G, o> we shall have Ky 1p, + K, .p,+K;, ee ayeene Ha iP,=9, Ky 2p, + Ky op, +Ks op,+ oO. tse 7035 K, .p,+K,,.p,+K,.p,+ Bist + Ki. P,=0. These equations give p,=p,=....=p,=0, or F(Gy, oy, Jy, GF, st =0, or 2G, Jy, ee: Oye * Ops tao Now if we put ZG, op ce? es) a i LyGy, Ke cl, e™> , o=G,, AL) then we shall have S22 Dive Ky, U ey Ak c= 2%, “ar Ley, Ky, 6, oq ote tens (3) The first of these formule may be proved thus: since 2G, Jy, = 2G, Jy, therefore 22,6, K, Jy, = 22,G,, J, KK, 0; that is (see equations B), =A 2Gy I, Ky os or basal ye» Whence a ae Also, for the second of these formulx, since by equations (2), section 6, we have =(K,, oo yee. ok’, ¢')=0, when ¢ and ¢’ are unequal, =e when ¢ and ¢’ are equal ; : hence S1=(G,, K cv, Ay int g—2(J, G PLS ot Tw = 5 G,, cl ON ELLIPTIC AND HYPERELLIPTIC FUNCTIONS. 347 Hence Jy, c= : " G,,, a 3,2 (G,, on JK’, e = 5 oy, ec! a5 2,€y1, ee ce? To ' or ds =9 » eT aeiey, ok ec This formula may be written thus, by merely changing the letters: ’ T 1 ’ J v,e = 3%, ot 2a a(G J a a, os v,B a, G,, ty, ar x aaa(G,, a9 a ak, gy, es bol A and o. ge ec — 9 G,, gk a ar = .2(G,, pa, aka, jp e) a aoe eK’, e as 2 2,(G,, ay, aka, oe a) > therefore 3,(J', K’, J’, 0K’, .) = 5 3G, By, eG, Ky, 0) i gi = Gy, aN ACH ak, » ro = (Ga, ple aI, ak », at K’,.): But 3", K’, = 5G, A, Comes G,, c! oe J, Ne a =0; e hence >,G,, aa aS > G PUGS eo: . . . e . . (4) VV, Section 9.—Let us now put E(u,uu,.- +. )=2 Bu, u,€, - then v,c vy ¢~-y,c? E(uuju,. ++ )=33,3,2,6,, Jo, uu bh Vy Cy Mh ve? E(u, + 2w,, u,+ 2, lay )= 32,2 ,2,,G,, J (u,+ 2w,)(U.+ 2w,) Bm eB aH (tb, ,-- - Us) +S, 3,0,U 8, J, 4+3,2,5,,0,u,6, J. BV CTV, ho ey ie BoC Vy Be, +23, ,3,,0,0 G, J Pvc Uy he Cy Me Now 3,G,, ht a 3,G,, ulm K, te m Ky ot eens) * )= me, : hence 35,3 ,0 UG, Jo p= S52 Gy, Fo, w= vey 5 also 23,226), wJe, wr Ye= 2e,0, E(u,+2u,. 0. -)=E(u,. 2.) +23,¢,(t,+ ,). 348 REPORT—1872. Now let us define a symbol, J (yy Ue =I Mare Yal(uu,. Ve then, when v, becomes v,4+2m,7r...., wu, becomes w+ 2(K) m,+Ky 9m,+ Ky ymt....)=u,+2u,, and therefore J (Y+2m,7, v,+2m7, +....)= gens Bchonh UmT2E ney (+o) —2En6,(%,+o) Al(u.u ) ; BOE ae fale eye ane Aus, ey ee Section 10,—Let us now recall the values of 6, , (section 8) defined by the equation 6, .=2,G, ,K’,, ..7, and let us assume = r,6,, Pata. ot foc 3+ eevee 10,, ? and let us ascertain the values of u,u,v,.... when v,v,.... become v,+6,%, v,+6,i,.... Thus u, becomes it 1 ; , ra (Ky 1% +Ky out... -- Ky a) + 7 (Ki, 19, + Ky, 20,+.-.- Ky 6, t= + Kyi SG, 7K, +736. 3K’, 5 +7 5.G Gk’. ot. cal Tos Taf +K, (7,36, sh’, »+7.3,G, oK’, +1,3,0, 0K’, gk one Pine ie rea 12 VV, vv, 2 + K, 3(7,2,G,, 3K’, 1 + 7,3,G,, 3k’, 2 + r,2,G,, 3k’, 3 pee ce yi Pas ge =u, (7,5,2,6 KS 1K, ak r= = G K’,, 2K, oe esa ) V, Be Boy, B A ' ' , im te =u tr Ky try ot7 Ky gt... =mto i, so u, becomes u,+w',i, U,,U,+w'i,+.... We will now investigate the value of J(u, +26, v,+20,2,....) —- Og aye 14 U,+20 Qeyreeeee Alu, + 20" i, u,+ 2Qu' i; arate ¥: Now E(u,+2w't, u,+20'2....)=E(u,, uu,....) +i3, 23,0 UG, Te, ptt, 226), Je, ye oly — 22,2 ,3,,8,, To, ye es Bo VC Vy eo Cy Me Vy ee Cy But 233,30 UG, J =712,2,2,,(7,K',, i+ re ot rie gees )u,G,, ie ne ev Cy Cy Mh ON ELLIPTIC AND HYPERELLIPTIC FUNCTIONS. 349 But 2, > ,%,G,, Pa ASS ING = 24 3,=,,G,, le Ze Nie =(by 1 and 3 of section 8) 3,{J',..— 5G, a} and therefore i3,3,3,,2,7,G,, Jo, u's, Me= Shr o, it 7 atte gach: Vy Be Cy =*" 5 (rs, 17,6, 9+7,6,, 3+ eee )}u, =i3,€'U,— 5 (ry, Ary, trst....)=t3,€'U,— ‘ SY, Similarly, i3,3,5,6,, J, 0/04 = Pe he 53 Lastly, 3356) Jee a FIST Ky eR, ote Ka CR i: --) By Be ey Me eerie: SoG de Ke AX & wie Vy CyB , ' T ' = BSryry StI ¢, K aa D) G,, Kk ¢, at AX , / T 1 ’ = aa & ay K ¢ Shes 3 SBT yTy Ve, K c, A! ! U = Se cH oT BIO: Whence we have J,(v, + 26,7, v,+26,7,...-)=g-e. LZ _6' ol -—tD Vy 4 — 23,6). + 2,799 eet uy +o viji E(u, sat al(uye,. aa — Zr, (%+6,o% =e." et MT (vv... aire ie From this expression, combined with that given in last section, we may develop Jc(v,v,v,....) in a series of exponentials. The full expression is given by Kénigsberger, Crelle, lxiv. p. 19. Section 11.—Hitherto our investigations have had reference chiefly to whole periods. We will now investigate some formule involving half periods. To determine Al(u,—K,. Pe f By a former equation, we have t ¢ dlog, al xi d log. Al(u,+K,..)—d log, Al(u,. . = — 3, J,— el du, 350 REPORT—1872. Al(u,+ K,....)=Ce Fain, .)al(u,....),3 whence Al(u,+2K,....)=Ce +O) ey ey ms al(u,... a» VP Ce 25 12m LOK) Ay On at Now put u,= ily a ...3 then, since (Crelle, xlvii. p. 301), a a a a i Ke Al(—K,, —K,,...)=Al(K,, K,....), wehave Ci" “*=1, C, Salar ae and therefore ee a -35,{u,4+ 3") 1, Ke... ee Al(u, eae )alu, 135 es Arce ti." 3,25 ¢ tf DY deat Fila, We will next investigate the value wu, assumes when v,.... becomes v,—m,r+6,2,,.... (see Crelle, xlvii. p. 305). It is plain that 2 u, becomes Uae =,m,K), oh - 3,K, yoy and 3K, ,6,=2,K, 3 1 uv, w= Sy hy, ye ea, HGS T =75,7,K'), mn ; and therefore the required value of u, is (mm,.... 7,r,.... being here 0 or 1) a 1 wu, —(m, Ky +m,K, ot+....)+07,K), 1 +7,K') o+....)=u,—K, (Weierstrass, 1. ¢.). Section 12.—Hence J(u, we mya 8,2) — Now ae gees ew) =32,2,2,G (u, OK Mu Vy Jou ON ELLIPTIC AND HYPERELLIPTIC FUNCTIONS. 351 a =E(uyu,.. ..%4,)—43,3,3,6,, Jo, Ket, -$3,3.3,6,, Je, JK, Mo Vy he Cy Me Vy Cy ve +4330 G/ J. KK Wises iflas Cy: pure We, Co But S356 J. hae ib Vs fic Cy J Be. =, 5, 2-(m,K,, ym Ky at os. =, ye on Gi. its ute =S 55 o Mor Gy, (mK, +m, K, -+m,K, +....) en Cy CV, fh —12,{2,2,6,, Pils On. pb Kot hacks +2) hu, => > M3 oe —7z,{7 0", je 5 Gs, cae Cae 5, 2)+ Peet o }u, pM Cc, he = =(mI., 1 + mJ o, at MJ 3 an git ue cml t3(7",9'., 1 + tN at tad 0, 3 a5 me ue . 5 irG, 1, + Gy, 4+ . +r, (Gy 9%, +G,, Agee) api oa = D Ete oe 1D,€ + 5 Sr Yy Again, 3,05, wre, ph K= S22 1G, Fo, LAK, PSK, ob LSM K,, y— Spit K's, pi} Th 5,39 103,3,5,G6,, Jo, Ky, Ko, — ta dptty p52 Gy, wo, oKy, K's, o Vy Me Cy Vy A Pe Vs he C,H, KAZ B MyM Baer Oy, we, why, Ko yy — BBM” yer Fy, Wo, phy, pe, pt CCB Vy Be ey p PPP BV, Bey & , . ; =F, 2mm, 2,3 ,(2,G,, pia We, ie AL. 2, SM 7, (3,2,,G,, vas ae ¢, aK, A vue, we vy Ue ve V, We, ep tyr 32, 3,6, Jy, pX's, pe, up 2p Bau, pas Ky, pK ot Tv = F,S,My My ZI o, XK, PU ~i3,3m758,(J, jee 9 Gr JK, R , a3 mr 3(F ‘sass a0F »)K Noe 35,7 787 Pe a, »)B. ' =3,(mI, +m,J, ot... mK, +m, K, ot...) ~i3,(mK, ,+m,K, ot... ry, Ardy, ott), ot +--+) 2 mK, mK, ot .. ++ mS’ o #7 S'o ot «os -) a 2(7,5",, a Fils, ot Pia sais bhi te 7, K’,, 1 “i Bae. ofrK,. 3+ * fue & ) 352 REPORT—1872. i in + = SE yM TBE, Ky, 4 + Bays mG K, yt43,3p7s" vv; p! C, pe, pp p'-p, p! . . s ' ’ =F ,€0¢ ha teow, + Ur Bmy"y i 13 ,€ oe ,€' ,w aE PROG Moreover a sy t— $. K) Al(u,—K,....)=e ATG U way — Z(om,J pred, aio orl, tr’, au, —a(maK, J nt. a 17). Al(u, ae Me cg la es Pia w! @)) —_ Al(u,. Aa ae Combining these results we have U E(t, Wo, ie. (Uy, Uys U Je(v,—pyrt+ot....)=e ) Al(u,u,. tara) a? ae Sad be lp where U=— SeeoMe+ ide ete — 9 2 ea ZA -EWe ~9 >.€ ot Oy Symyry a Ze ce —33e'' +g 2\",5, + e,u,— ide u,—43.€,0,+ : Sew’ + J .€ Wot ZEW os Now X,€ Wp — B,€,W' = =.{(m,K,, y+m,K, o+m,K, gt--. drs", 1 ea at Ts? ont ED —%{(m,J,, ptm, gtmJ, erie as 7K’, ie ci ot7,K", Re ee) = 5 (mr, bing, + = 5 ay: Consequently, substituting this in the preceding formula and reducing, we shall have a . U=— 3 3,7, (¥,— 2,7 + 36,2); and therefore Sone Uy) ts r (uv, —Am a+h0i - ; 2 Uh 8 .U,), =e ie ee F.(,— dr + 3d,i...), which is the formula 60, p. 305. Weierstrass then shows that we are able to expand J,(v,—m,r+d,i....) in a series of exponentials. Section 13.—The theoremsjust given contain in fact thesolution of what Clebsch and Gordan have called the ‘ Umkehr Problem,’ as applied to the hyperelliptic Al(u,u,. oy eat we have also shown that Al(w,u,....) depends on J(v,v,....), where V,, 4, functions ; for we have already given al(u,, u,....) ON ELLIPTIC AND HYPERELLIPTIC FUNCTIONS. 353 are connected linearly with w,u, &c., and J,(vv,....) can be expanded in a series of exponentials. Moreover, we now see that Al(w,w,....), depends on J(v.—m,r+o7....), when J.(v,—m,r+6,i....) can be expanded in a series of exponentials. Hence al(u,w,....), can be expressed as the ratio of two series of exponentials, a theorem equivalent to the well-known sin am 2Kx 1 Ox 3 WE Bar" iSiction 14.—We shall conclude this part of our subject by giving the ex- pansion of hyperelliptic functions in terms of divided arguments as given in Dr. Weierstrass’s second paper. Let R(w)=(#—4,)(@—4,).. . .(@ Ay, 4 1)s P(x) =(«—a,)(w—a,)....(w—a,), R(w)=P(w) Qe, Q(a)=(e—a,)(e—a,)....(@—@,), i: a dav, L a CN aN du,=5 5 v,— Sie " ¢,—4, : WV Re, a x —d, : VRe, q 1 Piw,) de, pea 5 dx, Pa, dx Boo fa Vhe i 2 aE, V Re, aed 2 =O» MB i, Pia dx i abe dx. Pz lx duj= 5 Od ng 5 ithe + pele tig x i ay" Re, vi,—@, NRe Any one of these equations may be written 32 ‘ Ee, : aoe — du } <_ i —t rs Gee Vv Rw, where & applies to », and extends from 1 to p. Wow let x’, v)....0,', 0", 22"... 0"... ky es @,. aig ) be a set of mp variables Ejacean adie to ‘ei arg dtnonts Whi Mh oe sa i ever e Rieu Ww, U te) yy OY aes (m being an even ree so that i oes. da, i sl Pa de, me 35 Soa Ve a ee pe —————— eee uv —a : 2° a —a Au 1 c ah N Re, w—a, WV Re! eee da™ 35° Se ve 7” Z aC) (ir) oa, Ravi ' ' 1 ” Dect he dx, ”, 1 Pz dar, a ein aa i igo sar eG CC 2° a,—a, V Re 7 2" ela, VRa iis 1 P. “aie d: a) So —*_ — qd un), DIS 1) MV Rel 3504 REPORT—1872. 1 Lae da™ 39 2° Gora num) > wy WV Ra Ra”) Pp also let M(x) be a rational and entire function of the ("P)e N(a) one of the (2 —1 }th order ; also let P(w)M?(w)—Q(v)N*(v)=11(v) (av), where M(w)=(w—a)...., (@—a,), (@—2))...., (@—2,), pe (a—a”) o, (aa), we consequently have for ¢(a,), where a, is one of the roots of P(#)=0, Qa, NG) M(a,) mine a1, H15 aa, vy, &e. from the hyperelliptic differential equations by Weierstrass has shown that it is possible to deter- $@,) => reversion of series, and that consequently in terms of w,, ww, w,- _ 94) Qa,) But, by Abel’s theorem, wr ” m) Uy =U, +U+...- +ul ? ! Dea aaa ee) “| (m ), te (m) (m) may be expressed by a series f(u,..u{ Us. Uys is Un) &e.= 2.0% , ” — (m) U, Ubu ieee FUZ . eee abies wy Now let WH=y=..., SU =o t, ene dems pe ( ee Up =Ug= 00. sult) ’ (Ce ' U U =u=..,. =u =o; (4) Mia up\ Qa J A; B prin Or, | B other words, the arguments may be taken as small as we please. TIDAL OBSERVATIONS. 355 Report of the Committee appointed for the purpose of promoting the extension, improvement, and harmonic analysis of Tidal Observa- tions. Consisting of Sir Wit11am Tuomson, LL.D., F.R.S., Prof. J.C. Avams, F.R.S., J. OtpnHam, Wit11amM Parkers, M.Jnst.C.L., Prof. Rankine, LL.D., F.R.S., and Admiral Ricuarps, R.N., F.RS. Drawn up by Mr. E. Roberts, under direction of the Committee. 1. Tue results already deduced from the discussion of tidal observations by the method of harmonic analysis being scattered through several succes- sive reports, it has been thought highly desirable to collect and rearrange them in the present Report for comparison and facility of reference, along with the results obtained during the past year. A full description of the method pursued in the reduction of the observations is first given in order that the results may be more readily understood. The explanation is the same generally as that contained in the Committee’s first Report ; additions and alterations haye, however, been made where found necessary during the reduction of the observations. 2. The chief, it may be almost said the only, practical conclusion deducible from, or at least hitherto deduced from, the dynamical theory is, that the height of the water at any place may be expressed as the sum of a num- ber of simple harmonic functions* of the time, of which the periods are known, being the periods of certain components of the sun’s and moon’s motionst. Any such harmonic term will be called a tidal constituent, or sometimes, for brevity, a tide. The expression for it in ordinary analytical notation is A cos nt-+Bsin nt; or R cos (nt—e), if A=Rcos e and B=Ksine; where ¢ denotes time measured in any unit from any era, » the corresponding angular velocity, the speed, as it will henceforth be called for brevity (a quantity such that 27 ig the period of the function), R and e the amplitude n and the epoch, and A and B coefficients immediately determined from obser- yation by the proper harmonic analysis (which consists virtually in the method of least squares applied to deduce the most probable values of these coefficients from the observations). 3. The chief tidal constituents in the North Atlantic Ocean, indeed in all localities where the tides are comparatively well known, are those whose periods are twelve mean lunar hours and twelve mean solar hours respec- tively. Those which stand next in importance are the tides whose periods are approximately twenty-four hours. The former are called the lunar semidiurnal tide and solar semidiurnal tide; the latter, the lunar diurnal tide and the solar diurnal tidet. There are, besides, the lunar fortnightly tide and the solar semiannual tide§. The diurnal and the semidiurnai tides have inequalities depending on the excentricity of the moon’s orbit round the earth, and of the earth’s round the sun, and the semidiurnal have in- equalities depending on the varying declinations of the two bodies. Each such inequality of any one of the chief tides may be regarded as a smaller superimposed tide of approximately equal period, producing with the chief * See Thomson and Tait’s ‘Natural Philosophy,’ §§ 53, 54. t See Laplace, ‘Mécanique Céleste,’ liv. iv. § 16. Airy’s ‘Tides and Waves,’ § 585. t See Airy’s ‘Tides and Waves,’ §§ 46, 49; or Thomson and Tait’s ‘Natural Pkilo- sophy,’ § 808. § See Airy’s ‘Tides and Waves,’ § 45; or Thomson and Tait’s ‘ Natural Sr uneephy: § 880, B2 356 REPORT—1872. tide a compound effect which corresponds precisely to the discord of two simple harmonic notes in music approximately in unison with one another. These constituents may be called, for brevity, elliptic and declinational tides. Thus we have the following schedule of tidal constituents :— Speeds Lunar. Solar. The lunar monthly and solar annual (elliptic). 2 o—w n The lunar fortnightly andsolarsemiannual| 5 9 9 (declinational)): 5 ceycdyp eye) col) one 4 q The lunar and solar diurnal (declinational) . 4 Y 2 i 9 Var se Ve a The lunar and solar semidiurnal . . . .2 2(y—o) 2 (y—n) . yt o—@ y+ 0 The lunar and solar elliptic diurnal . . . 7 Yaa vinnie: Ye Sieh oie y—3e+m y—3n EP = The lunar and solar elliptic semidiurnal . . 4 2 ates ee at The lunar and solar declinational semi- 9 dural: epee Lodteratceine set ones 4, Here y denotes the angular velocity of the earth’s rotation, and o, n, a those of the moon’s revolution round the earth, of the earth’s round the sun, and of the progression of the moon’s perigee. The motion of the first point of Aries and of the earth’s perihelion are neglected. The slow variation of the lunar declinational tides due to the retrogression of the nodes of the moon’s orbit may be dealt with, probably with sufficient accuracy, according to the equilibrium method. The inequalities produced by perturbations of the moon’s motion, other than of evection and variation, are insensible. These perturbations give tidal constituents, which must be included in the analysis for all places at which the range of tide is considerable. The follow- ing are the speeds of these perturbing elements for semidiurnal tides :— 2y— ot w—2Qn 2y—30— w+2n 2y—4do4+2n 2y—2n Lunar evection semidiurnal. . . | Lunar variation semidiurnal . . { There are also evection and variation diurnal tides, but which, from their nature, must be necessarily very small, and consequently have not hitherto been included in the analysis. 5. There are besides, as Laplace has shown, very sensible tides depending on the fourth power of the moon’s parallax*, the investigation of which must be included in the complete analysis now suggested, although for simplicity they have been left out of the preceding schedule. The amplitude and the epoch of each tidal constituent for any part of the sea is to be deter- mined by observation, and cannot be determined except by observation. But it is to be remarked that two of the solar elliptic diurnal tides thus indicated have the same period, being twenty-four mean solar hours, and also the period of one of the lunar diurnal tides agrees with that of one of the solar diurnal tides, being twenty-four sidereal hours, and that the period of one ~ [* The chief: effect of this at any one station is a ¢erdivrnal lunar tide, or one whose veriod is eight lunar hours. Values of this haye been determined from the tidal observa- tions. at Liverpool, Ramsgate, Portland Breakwater, &c.] TIDAL OBSERVATIONS. 357 of the semidiurnal lunar declinational tides agrees with that of one of the semidiurnal solar declinational tides, being twelve sidereal hours; also that the angular velocities y—o+a@ and y—o—zq are so nearly equal, that obser- yations through several consecutive years must be combined to distinguish the two corresponding elliptic diurnal tides. Again, one of the lunar varia- tion tides has the same period as the chief solar semidiurnal tide. This would be of great importance for tidal theory, were it not that its magnitude must be so small as to be scarcely seusible. Each lunar declinational tide yaries from a minimum to a maximum, and back to a minimum, every nine- teen years or thereabouts (the period of revolution of the line of nodes of the moon’s orbit). Observations continued for nineteen years will give the amount of this variation with considerable accuracy, and from it the propor- tion of the effect due to the moon will be distinguished from that due to the sun. It is probable that thus a somewhat accurate evaluation of the moon’s mass may be arrived at. 6. There are also shallow-water tides which depend on the rise and fall of the tide, amounting to some sensible part of the whole depth of the water, or, which comes to the same, the horizontal velocity of the water being sensible in comparison with the velocity of propagation of a long wave through some considerable portion of the sea which sensibly influences the tides at the point of observation. Helmholtz’s explanation of compound sounds, according to which two sounds, each a simple harmonic, having mt, nt for their arguments, give rise, if loud enough, to sounds having for their arguments (m+n)t, (m—n)t, suggests that the compound action of the solar and lunar semidiurnal tides must give rise to shallow-water tides, whose speeds are 2(¢—n) and 2(2y—o—n). The action of the solar or lunar semidiurnal tide alone must also (by the case m=n) give rise to shallow-water tides. The following are the speeds of these compound shallow-water tides which have (with one exception not yet tried) been found to be sensible at some of the places dis- cussed hereafter :— Speeds, 2(¢—n) fortnightly. 2(2y—a—n) quarter-diurnal, Helmholtz compound shallow- 2y—4o4+2n water tides. . . . « . 2y+2c—4n | 2(2y—B0+ 2) 222y+ o—3n) Onc of the semidiurnal components contained in the above list has the same period as one of the variation semidiurnal tides, and is therefore to be held accountable for any deviation, whether of magnitude or of epoch, which the tide of this period, calculated from observation, may show from the values which might be expected merely from the lunar perturbation alone. 7. The methods of reduction hitherto adopted*, after the example set by Laplace and Lubbock, have consisted chiefly, or altogether, in averaging the heights and times of high water and low water in certain selected sets of groups. Laplace commenced in this way, as the only one for which observa- tions made before his time were available. How strong the tendency is to pay attention chiefly or exclusively to the times and heights of high and low water is indicated by the title printed at the top of the sheets used * See ‘ Directions for reducing Tidal Observations,’ by Staff-Commander Burdwood (London, 1865, published by the Admiralty) ; also Professor Haughton on the ‘“ Solar and Lunar Diurnal Tides on the Coast of Ireland,’ Transactions of the Royal Irish Academy for April 1854, } semidiurnal. } quarter- diurnal. 358 REPORT—1872, by the Admiralty to receive the automatic records of the tide-gauges ; for instance, ‘‘ Diagram, showing time of high and low water at Ramsgate, traced by the tide-gauge.” One of the chief practical objects of tidal investi- gation is, of course, to predict the time and height of high water; but this object is much more easily and accurately attained by the harmonic reduction of observations not confined to high or low water. The best arrangement of observations is to make them at equidistant intervals of time, and to observe simply the height of the water at the moment of observation irrespectively of the time of high or low water. This kind of observation will even be less laborious and less wasteful of time in practice than the system of waiting for high or low water, and estimating by.a troublesome interpolation the time of high water, from observations made from ten minutes to ten minutes for some time preceding it and following it. The most complete system of obser- vation is, of course, that of the self-registering tide-gauge, which gives the height of the water-level above a fixed mark every instant. But direct ob- servation and measurement would probably be more accwrate than the records of the most perfect tide-gauge likely to be realized. 8. One object proposed for the Committee is to estimate the accuracy, both as to time and as to scale of height, attained by the best self-registering tide-gauges at present in use, and (taking into account also the relative costliness of different methods) to come to a resolution as to what method should be recommended when new sets of observations are set on foot in any place. In the mean time the following method of observation is recommended as being more accurate and probably less expensive than the plan of measure- ment on a stem attached to a float, often hitherto followed where there is no self-registering tide-gauge. A metal tube, which need not be more than 2 or 3 inches in diameter, is to be fixed vertically in hydrostatic communication, by its lower end, with the sea. A metal scale graduated to centimetres (or to hundredths of a foot, if preferred) is to be let down by the observer in the middle of the tube until it touches the liquid surface; and a fixed mark attached to the top of the tube then indicates the reading which is to be taken. Attached to the measuring-scale must be one or more pistons fitting loosely in the tube and guiding the rod so that it may remain, as nearly as may be, in the centre of the tube. The observer will know when its lower end is precisely at the level of the surface of the liquid, by aid of an electric circuit completed through a single galvanic cell, the coil of a common tele- graph “ detector,” the metal measuring-scale, the liquid, and the metal tube*. By this method it will be easy to test the position of the water-level truly to the tenth of an inch. It is not probable that tidal observations hitherto made, whether with self-registering tide-gauges or by direct observations, have had this degree of accuracy; and it is quite certain that a proper method of reduction will take advantage of all the accuracy of the plan now proposed. 9. An observation made on this plan every three hours, from day to day for a month, would probably suffice to give the data required for nautical purposes for any harbour. It is intended immediately to construct an appa- ratus of the kind, and give it a trial for a few weeks at some convenient harbour; and if the plan prove to be successful and convenient, it will come to be considered whether observations made at every hour of the day and {* Instead of the galvanic detector, an hydraulic method may be found preferable in some places. The latter consists in using a stiff tube of half inch diameter or so, instead of the solid metal measaring-bar, and testing whether its lower end is above or below the leyel of the water by suction at the upper end.] TIDAL OBSERVATIONS, 859 night might not, all things considered (accuracy, economy, and sufficiency for all scientific wants), be preferable to a self-registering tide-gauge. 10. One of the most interesting of the questions that can be proposed in reference to the tides is, how much is the earth’s angular velocity diminished by them from century to century? The direct determination of this amount, however, or even a rough estimate of it, can scarcely be hoped for from tidal observation, as the data for the quadrature required could not be had directly. But accurate observation of amounts and times of the tide on the shores of continents and islands of all seas might, with the assistance of improved dynamical theory, be fully expected to supply the requisite data for at least a rough estimate. In the mean time it may be remarked that one very important point of the theory, discovered by Dr. Thomas Young and inde- pendently by Airy*, affords a ready means of disentangling some of the complicacy presented by the distribution of the times of high water in dif- ferent places, and will form a sure foundation for the practical estimate of a definite part of the whole amount of retardation, when the times of spring- tides and neap-tides are better known for all parts of the sea than they are at present. ‘To understand this, imagine a tidal spheroid to be constructed by drawing an infinite number of lines perpendicular to the actual mean sea- level continued under the solid parts of the earth which lie above the sea~ level, and equal to the spherical harmonic term or Laplace’s function, of the second order, in the development of a discontinuous function equal to the height of the sea at any point above the mean level where there is sea, and equal to zero for all the rest of the earth’s surface. This spheroid we shall call, for brevity, the mean tidal spheroid (lunar or solar as the case may be, or lunisolar when the heights due to moon and sun are added). The fact that the lunar semidiurnal tide is, over nearly the whole surface of the sea, greater than the solar, in a greater ratio than that of the generating force, renders it almost certain that the longest axes of the mean lunitidal and solitidal spheroids would each of them lie in the meridian 90° from the disturbing body (moon or sun) if the motion of the water were unopposed by friction ; or, which means the same thing, that there would be on the average of the whole seas, Jow water when the disturbing body crosses the meridian, were the hypothesis of no friction fulfilled. But, as Airy has shown, the tendency of friction is to advance the times of low and high water when the depth and shape of the ocean are such as to make the time of low water, on the hypo- thesis of no friction, be that of the disturbing body’s transit. Now the well- known fact that the spring-tides on the Atlantic coast of Europe are about a day or a day and a half after full and change (the times of greatest force), and that through nearly the whole sea they are probably more or less behind these times, which Young and Airy long ago maintained to be a consequence of friction, would prove that the crowns of the lunitidal spheroid are in advance of those of the solitidal spheroid, and therefore that those of the latter are less advanced by friction than those of the former. It is easily conceived that a knowledge of the heights of the tides and of the intervals between the spring-tides and the times of greatest force, somewhat iaore extensive than we have at present, would afford data for a rough estimate of the proper mean amount of the average interval in question—that is, of the interval between the times of high water of the mean lunitidal and mean solitidal spheroids. The whole moment of the couple retarding the earth’s rotation, in virtue of the lunar tide, must be something more than that calcu- _ * See the collected works of Dr. Thomas Young, vol. ii, No. LIY. (London, 1855, John Murray), and Airy’s ‘Tides and Waves,’ §§ 459, 044, 360 _ REPORT—1872. lated on the hypothesis that the obliquity of the mean lunitidal spheroid is only equal to the hour-angle corresponding to that interval of time. 11. We know, however, but little at present regarding the actual time of the spring-tides in different parts of the ocean; and it is not even quite certain, although, as Airy remarks, it is extremely probable, that in the southern seas they take place at an interval after the full and change, although it may be at a less interval than on the Atlantic coast of Europe. There must be observations on record (such as those of Sir Thomas Maclear at the Cape of Good Hope, which Staff-Commander Burdwood showed to Sir W. Thomson in the Hydrographical Office of the Admiralty) valuable for determining this very important element for ports on all seas where any approach to a knowledge of the laws of the tides has been made. To collect information on this point from all parts of the world will be one of the most interesting parts of the work of the Committee. 12. Another very interesting subject for inquiry is the lunar fortnightly, or solar semiannual, tide, the determination of which will form part of the complete harmonic reduction of proper observations made for a sufficient time. The amounts of these tides must be very sensible in all places remote from the zero line* of either northern or southern hemisphere, unless the solid earth yields very sensibly in its figure to the tide-generating force +. Thus it has been calculated that if the earth were perfectly rigid, the sum of the rise from lowest to highest at Teneriffe, and simultaneous fall from highest to lowest at Iceland, in the lunar fortnightly tides, would amount to 45 inches. The preliminary trials of plans for harmonic reduction referred to below, make it almost certain that hourly observations, continued for a sufficiently long time at two such stations as these, would determine the amount of the fortnightly tide to a fraction of an inch, and so would give immediate data for answering, to some degree of accuracy, the question how much does the solid earth really yield to the tide-generating force ? 13. A beautiful synthesis of the complex dynamical action to which the semidiurnal tides are due, imagined by Laplace, will be used in this Report to enable us to avoid circumlocution. A number of ideal stars (‘astres fictifs’?) are assumed to move, each uniformly in the plane of the earth’s equator, with angular velocities small in comparison with that of the earth’s rotation, so that the period of each relatively to the earth is something not very different from the lunar or solar twenty-four hours. Each one of the approximately semidiurnal tides (§ 3) is produced by one alone of these ideal stars. 14. One of the ideal stars is what is commonly called in England the “‘mean sun,” being that point of the celestial sphere in the plane of the earth’s equator whose hour-angle is equal to mean solar time: for brevity we shall call it S. Another of them might be the “mean moon” similarly defined (called M); but, to allow the same Tables (§ 16) to be used for the reduction of tidal observations of different years, we shall take it as a point moving in the plane of the earth’s equator, with an angular velocity equal to the mean angular velocity of the moon, and set at 0°-0 for its hour-angle at the com- mencement of any series of observations t. Similarly K might be the first point of Aries, but, for the same reason, will * Thomson and Tait’s ‘Natural Philosophy,’ § 810. + “On the Rigidity of the Earth,” W. Thomson, Trans. R. 8., May 1862; or Thomson and Tait’s ‘ Natural Philosophy,’ §§ 832-849. { Other hour-angles to those here given were first used, but not proving of any practical utility, the above were substituted for them, simplifying to some extent the ultimate cor- rections depending on these assumptions. TIDAL OBSERVATIONS. 361 be taken as a point in the plane of the earth’s equator, set so that its hour- angle is 0°-0 at commencement. O is an ideal whose right ascension increases twice as fast as that of the mean moon, and which is also set with 0°-0 for its hour-angle at com- mencement. L and N are ideal stars whose rates of increase of right as- cension are respectively greater than, and less than, that of the mean moon, by a difference equal to half that of the mean moon relatively to her perigee. 15. General Schedule of the diurnal, semidiurnal, terdiurnal, and short- period shallow-water tides, which have been included in the analysis, show- ing speeds in degrees per mean solar hour, and periods in mean solar hours :— Diurnal Distin- — et Be ont guishing Speeds. Periods. Letters. 3S h ) Y—N=I15'0000000 §=—24'0000 TS, !_ RE RARER GRE Mile Jeanne PRN oS cS ctecssOeeiet | roe seone P ¥—2n=14'9589314 240659 K Y=15'0410686 23°9345 M y¥—T=14'4920521 24°8412 lip 9S) Ea Sees cr oe ae Sees RY) S53 ERE are alee O Y¥—20=13°9430356 25°8194 JT -y+o—w=15'5854433 23°0985 Q y¥—30-+w=13'3986609 6-268 684. EE oS ccceaseete ame ME paaees 5 > gue EARRRAB Rear 0 a fre poor OMS po treet tees DONE EM Cc tivccssseccene eee Terdiurnal pe Speeds. Periods. a h PREM ciececesosuuce ee | emeersc M 3(y¥—9) =43°4761563 82804 eee eee tee teneee 1-diurnal (shallow-water) A Speeds. SS) 6(y—n)= 90"0000000 M 6(y—o) =87°9523126 h 470000 4°1402 i ~ Periods. Semidiurnal cae aks ak 07 => Speeds. Periods. oO 2(y—7)=30"°0000000 =: 2"0000 2Y—N=30'0410686 11°98 36 2y—3n=29'9589314 1270165 2y = 30°0821372 ©11°9672 2(y—o)=28-9841042 12°4206 2y—o—W=29'5284788 12°1916 2y—30-+m=28'4397296 81276584 2y—o+mw—2=29'4556254 12'2218 2y¥—30—w+2n=28'5125830 12°6260 2(y—20-+7) =27'9682084 12°8718 2(y+o—2n)=31'0158958 11°6070 Quarter-diurnal’ (shallow-water) OF oo — Speeds. Periods. 4(y—n)= 6o.0000000 —~ "0000 4(y—9)= 5779682084 62103 4(y—39—3n) = 58°9841044 = 6°1033 a(y—So-+an)= 569523128 63211 Ay +39—37)= 60158960 — 5"g001 4-diurnal (shallow-water) —— pee ee eS es Speeds. Periods 8(y—)=1 20°0000000 3°0000 8(y—o)=116'9364168 =. 3" 1052 16. If ¢ denote time reckoned in mean solar hours from the commencement of any set of observations, vt (y- 27—27)E, (y—a)t, ke. 362 REPORT—1872., will be the hour-angles of the ideal stars. These have been calculated by successive additions for each integral mean solar hour of the year, and subtraction of 360 every time a number exceeding 360 has been reached ; and the results have been tabulated. Preceding each hour-angle, the num- ber which, multiplied by 15, most nearly agrees with it has been written. The following is a specimen page for one day of the Table thus formed :— 8 R T 2 K (y—n)t (y—2n)t (y—in)t (y—2n)t ye h 5 h a h ° h 3 h ° fo) re) ° 0°00 ° 0°00 ° 0°00 ° 0°00 Trg Fearing oz I 14°98 I 14°96 I 15°04 2 30 2 30°04. 2 29°96 2 S2.9192 2 30°08 3 45 3 45706 3 44°94 3 44°88 3 45°12 4 60 4 60°08 4 59°92 4 59°84 4 6016 552275 op aa foe 8 Cy Eels 5. aD Sy ores 6 90 6 90°T3 6 89°88 6 89°75 6 90°25 7 105 7 10515 7 04°85 7 04°71 7. OG? $8 120 8 12017 8 119°83 8 119°67 8 120°33 9. 735 O38 o 29 9 134°81 9 134°63 92351 3% 10 150 IO 50°21 Io 149°79 Io 149°59 IO 15041 lI 165 Ir 165°23 II 164°77 Ir 164755 ir 165°45 Iz 180 12 180°25 12 179°75 Iz 179°51 12 18049 13° 195 13 195°27 sy es 13 194°47 13... 195753 14 210 14 210°29 14 209°71 14 209°42 14 210°57 15 225 15 225°32 15 224°69 15 224°38 15 -225°62 16 240 16 240°34 16 239766 16 239°34. 16 240°66 17/255 17 255°36 17 25464. 17 254730 17 255°70 18 270 18 270°38 18 269°62 18 269°26 18 270°74 19 285 19 285'40 Ig 284°60 Ig 284°22 Ig 285°78 20 300 20 300742 20 299°58 20 299°18 20 300782 2I 315 2I 31544 2I 314'56 2I 34°14 21. 315°86 22) 330 22 330°46 22 320-52) 22 329°10 22 330°90 23 345 23 345°48 23 3445% 23 1344/95 23 345°94 8 M L N ~ 0 (y—n)t (y—-o)t (y-20-20)t (y—$o+20)t (y—20)¢ h > h 3 h s h A h 5 ° ° ° 0°00 ° 0°00 fe) 0'00 ° 0°00 Tels I 1449 I> 14°76 I (| 3422 I: Siaana ZO 2 28°98 2 29°53 2 28°44 2 27°89 3. 45 3 43°48 3 44°29 3 42°66 3 41°83 4 60 4 57°97 4 59°06 4 56°88 4° 55°77 5. 75 5 72°46 5 73°82 5. a7 XO 5 69°72 6 go 6 86°95 6 88°59 6 * 85°32 6 83°66 7 105 7 101'44 7 103°35 7 99°54 7 97°60 8 120 8 115°94 8 xr1811 8 113°76 7 ae 9 135 9 130°43 9 13288 9 127°98 8 125749 10 150 Io 144°92 IO 147°64 9 14220 9° 139743 Il 165 II 59°41 Ir 162"41 IO 156°42 IO :153°37 12 180 12 173/90 M2 7 7, II 170°64 IY 167-92 13 195 13 188"40 13 191°94 12 184°86 12 18126 I4 210 14 202°89 14 206°70 13 199'08 13 195°20 15 225 14. 217°38 15 221746 14 213730 14 20915 16 240 15 231°87 16 23623 15 227752 15 223°09 17 255 16 246°36 17 250°99 16 241°74 16 237703 18 270 17 260°86 18 265°76 17 255796 17 250°97 19 285 18 275°35 19 280°52 18 270718 18 264'92 20 300 Ig 289°84 20 295°28 19 284°40 19 278°86 2I 315 20 304°33 PB Cool 20 298762 20 292°80 22330 21 318°83 22 324°81 21 312°84 20 306°75 23 345 22% 333°32 23 339°58 22 327706 21 320°69 TIDAL OBSERVATIONS. 3863 8 J Q r (y—n)e (y+o—w)t (y—30+a)t (y—40+30—n)t h 2 h é h & h S ° re) ° 000 ° 0'00 ° 0°00 y 15 P pcesi59 TI 1340 I 14°73 2 30 2 wiFti7 2 26°80 2 29°46 3 45 3 46°76 3 40°20 3 44°18 4 60 4 62°34 4 53°59 4 58-91 Si 7S 5 77°93 4 66°99 5 73°64 6 90 6 93°51 5 80°39 6 83°37 7 105 7 10910 6 93°79 7 103°09 8 120 8 124°68 7 10719 8 3117°82 9 135 9 14027 8 120°59 9 13255 10 150 Io 155°385 9 133°99 Io 147'28 Ir 165 Il 17144 IO 147°39 II 162°01 12 180 12 187°03 Ir 160°78 12 17673 13 195 14 202°61 Iz 174'18 13 191746 14 210 15 21820 13 187°58 14 206719 15 225 16 233°78 13 200°98 15 220'92 16 240 L7 GAOT 14 214'°38 16 235°65 17 255 18 264°95 15 227°78 17 250°37 18 270 Ig 280°54 16 241°18 18 26510 Ig 285 20 296712 17 254°57 19 279733 20 300 21 31°71 18 267°97 20 6294°56 21 315 22 327°29 Ig 281°37 21 309°28 22 330 23. 342°88 20 294°77 22 324°01 23 345 © 35347 21 30817 23 338'74 8 y p or 2MS MS (y—n) (y—40—}0+n)t (y—20+n)t (y—20—3)t h o h ° h oO h °o ° ° ° 0'00 ° 0°00 ° 0°00 Er 1s I 14°26 I 13°98 ae 7ay Bin 390 pe TH 2 27°97 2 29°49 35. aS 3 42°77 3 41°95 3 4424 4 60 4 57°03 4 55°94 4 58°98 ball de 5 7128. 5 g"92 Cie kee: 6 go 6 = 85°54. 6 83:90 6 88:48 7 105 7 99°79 7 9789 7 10322 8 120 8 114°05 7 111'87 8 117°97 9 135 9 128731 8 125°86 9 132°71 Io 150 Io 142°56 9 139°34 Io 147746 Ir 165 10 1567382 IO 153°83 II 162'21 Iz 180 Il 171'08 It 167°81 12 17695 13 195 IZ 185°33 12 181°79 13 91°70 14 210 13 199759 13 195°78 14 206744 15 225 14 213°84 14 209°76 15 221°19 16 240 15 228°I0 Hh nasty 16 235°94 17) 255 16 242°36 nt eG ag7°7g 17 250°68 18 270 17 256°61 17 251°71 18 = 265°43 19 285 18 27087 18 265°70 19 28017 20 300 19 285°13 Ig 279°68 20 294°92 21 41s 20 299°38 20 293°67 21 309°67 22,3340 21 313764 21 307°65 22 324°41 23° 345 22 327°90 21 321°63 23 339716 364 _ REPORT—1872. rs) 28M 3MS 38M. (y—n)¢ (y+o—2n)t (y—4e-+2n)t (y+40—4n)t h * h 4 h 5 h 6 O° Oo ° 0°00 ro) 0°00 ° 0°00 r= 15 Te Gage I 34°24 EEA 2 qeso 2.) 32502 2 28°48 2 30°51 32 45 3 46°52 3. 42°71 3. 45°76 4 60 4 62°03 4 56°95 4 6102 Se SiS 5 77°54 5 7119 5: E7827 6 90 6 93°05 6 85°43 6 91°52 7 105 7 10856 7 $90;67 7 10678 8 120 8 124°06 8 113°90 8 122°03 3) OOS 9 7 g 128714 9 13729 190 150 Io 155708 9 142°38 IO 152°54 Ir 165 II 170°59 Io 6156°62 Ir 167°79 12 180 12 186'Io0 Ir 170°86 12 183°05 13 195 13 201°60 12 185'09 13 198730 14 210 14 21711 13 199°33 14, 213756 I§ 225 16 232°62 14. 213°57 15 228°8r 16 240 17 24813 15 227°81 16 244°06 17 255 18 = 253°63 16 242°05 17 259°32 18 270 19 279°I4 17 256:29 18 274°57 19 285 20 294°65 18 270°52 Ig 289783 20 300 21 310°16 19 284°76 20 305708 20" 405 22 325°67 20 299°00 21 320°33 22 339 23. 34917 20 313°24 22 335°59 23-345 o 35668 22 327748 23 -350°84 17. We will now describe the method of reduction pursued, in the first place confining ourselves to the statement of what was actually done for the year 1864 and the harbour of Ramsgate. A datum-line 10 feet below the previously supposed mean level was chosen*, and the height of the curves marked by the self-registering tide- gauge was measured from this datum-line in feet and decimals of a foot for each integral mean solar hour of the year, and entered in the Table. A period of 369" 3", or rather more than a year, was taken as being to the nearest hour twelve and a half lunations or twenty-five periods of spring- and neap-tides, and therefore giving a least possible amount of influence of the mean lunar and solar semidiurnal tides, each on the sets of averages used in the calculation of the other. This period has been used for the evaluation of the whole of the remaining short-period tide-components contained in the previous schedule, with the exception of the elliptic diurnal and semidiurnal tides, for which the follow- ing periods were chosen for similar reasons :— Lunar elliptic semidiurnal tides (L and N) 358? 6", Lunar evection semidiurnal tides (\ and v) 349% 22%, Lunar elliptic diurnal tides (J and Q) 3704 5". 18. These averages were taken according to the following rule :—First for the S tides, twenty-four means of the heights at 0", 1", 2",.... 23" of S hours (or ordinary mean solar time) were taken. Next for the M tides, twenty- four averages were taken of heights grouped similarly according to the M hours. In thus averaging for the M tides every height which was recorded at a time within half an M hour before or after 0" M time was taken as if it had been observed at 0" M time, and so for 1, 2", 3", &c. of the M time. The proper correction on this was applied afterwards, as will be described later * The true mean level for the year 1864 was found to be 10°192 above this datum-line, or ‘192 of a foot higher than was supposed. TIDAL OBSERVATIONS. 865 ($24). Other averagings were performed according to the same rule for the Kk, L, N, &c. reckonings respectively each averaging giving a group of twenty-four means. 19. The next step was to find for each of these sets of averages the coeffi- cients A,, A,, B,, A,, B,, &c. of the harmonic formule, A,+A,cos nt+B, sin nt +A, cos 2nt+ B, sin 2nt +A, cos 8nt+ B, sin 8nt, n denoting, as in § 2, the rate of increase of the hour-angle for each case ; for instance y for the K tides, y—o for the M tides, andso on. The condition to be fulfilled is that the values of this formula calculated for t=0,t=1.., t=23 may agree as nearly as possible, on the whole, with the twenty-four numbers of the group (the sum of the squares of the differences to be a minimum*), The tabular forms and rules given by Mr. Archibald Smith, and published by the Admiralty, for the harmonic reduction of the deviation of ships’ compasses, have been adopted mutatis mutandis, and have proved very convenient. 20. If, instead of including only seventeen coefficients, A,, A,, B,,..... A,, B,, the calculation had been extended to A,,, B,,, A,,, so as to include in all twenty-four coefficients, the calculated values would necessarily have agreed with the twenty-four numbers given by observation. But there was no apparent probability that any thing more than accidental irregularities and errors of observation could be represented by higher terms than A,, B,, and therefore these were the highest included. The following Table exhibits the results of this process for six series, the remaining series presenting similar features. The columns headed “ differences ” preserve the residues, however, and may be referred to should further study of the subject indicate that use- ful results are to be derived from them. ‘The greatest of them is :055 of a foot, and the maxima in each column are only from ~, to 34, of a foot. Values of A,, B,, A,, &c., to first Approximation. S} K L M N O (y—1) (y) (y-3e-3~) (y-2) (y—-Bo+3@) (y—2c) A, +0'0231 —0°2052 —9'0305 +0'0223 +oror8sr —0'2963 13 fi —0°0255 —0'0236 —0*0120 —0'0058 +o0'0048 +0°0687 A, +1°5598 —0'4540 —0'2276 —4°3176 +o°8191 —0°0994 B, +0'9923 —o'oo61 -++0°2669 +4°5037 —0'7342 —0°0007 Ags 00086 +0°0937 — 00096 —o'0138 —o'0c08 —0'0073 B, -+-0°0004. -+o'0015 --0'°0093 +0°0408 +o'orr! +0'0078 A, +0'0295 —0°0127 —0'0457 —0°5443 —0'0094. +0'0030 B, -+o°0009 —o'co2I —0'0927 —o'0878 —o'o122 +o'ec34. A; 00000 —o'005I —0'0023 +0'0032 —0°0013 +0'0022 B, -++0°0029 +0°0072 +-0°0046 -+o'0019 +0°0052 —0°C074 A, +0°0017 —o'oco8 —o'0050 —O'1132 —0'0287 —0'0062 B, +0'0068 +0'0027 —0'0079 —O'III4 —0'0024. + 00040: A, -~ +0'0008 -0°0030 —a'0056 +0'0021 —0°0022 +0:0202 B,° > +0'0046 —o'oorr +0'0043 —0'0031 —o'0004. —0'0084 A; +oroorr -+0'0058 —0'0421 +0°0295 +0'0048 —0'0057 B, +0'0028 —0°0933 +0°0312 —0'04.16 —o'ooor +0°0073 ING 10°1988 10°1989 10°1843 IO"1g92 10°1853 IO'Ig7I * According to Laplace’s method of ‘ least squares,” 366 Calculated. (1) 11°8234 12'0992 11°8255 II'I414 10°24.54 9°3442 876403 8°34.04 85202 91488 10°0677 11°0364 11°7584 12°0408 1178133 11'1660 10'2798 9°3918 8°6955 8°3844 8°5682 92166 10°1327 11'0908 (y—) Observed. (2) 11°8231 12'0976 11°8226 11°1528 10°2413 9°3386 8°6455 8°3371 8°5184 9°1539 10'0731 11'0268 11°7593 12°0420 118154. 11°1607 10°2897 9°3870 8°6889 8°3886 8°5781 9°2153 10'1360 11°0874 (y—40—40) omen Calculated. (1) 98159 10°0343 10'2272 10°4373 10°6552 10°5447 10°3081 IO‘I317 9°9976 9°9221 10°0186 9°9607 9°9119 IO‘OS1I 10'2596 10°4881 10*6960 10°5723 10°3 501 10'2197 9°9996 979041 9°9726 9°8655 Observed. (2) 9°8165 10°0483 10°2018 10°4.650 10°6342 10°5549 10°3057 10°1 864. 9°9850 9°9460 9°9894 9°9846 9°9°33 10'0704. 10'2839 10°4609 10°7134 10°5700 a3 39508 10°23 32 99912 99010 9°9838 9°8549 REPORT—1872. a oN Difference. (1)—(2) -++0°0003 ++o°0016 -+0°0029 —O'oll4. +o'0041 +0'0056 —0'0052 +0°0033 +0'0018 —0'0051 —0'0054. +0°0096 —0°0009 —0'0012 —o'0021 +0'0053 —0"0099 +0°0048 -++0°0066 —0'0042 —o'oolg +0'0013 —0°0033 +0'0034 Difference. (1)—(@) —o'0006 —o'0140 -0°0254 —0'0277 +0'0210 —0'0102 +0'0024 —0°0047 +0'0126 —0'0239 -+0'0292 —0°0239 +0°0086 +0'0107 —0'0243 0'0272 —0'o174 -0'0023 +0'0108 —0'0135 -+0'0084 +0°0031 —o'oli2 +0'0106 = Calculated. (1) 9°5336 9°5944 9°7901 10°0467 30'2872 10°5013 10°6300 10°6197 10°5148 10°3483 IO'I S501 10°0000 9°9408 9°9882 10°1539 10°3705 10°5 572 10'6729 1076636 10°5373 10°35 52 IO°IO4!I 9°8107 9°6030 Calculated. Q) 5°2674 82397 12°3265 154386 16°4609 15°8858 -14°0736 11°3474, 8°5247 6°1588 4°5765 4°1587 5°2398 8°1633 12'2161 15°3376 16°4241 15°9220 14°1568 11°4.504 8°5987 6°1570 4°5249 4°1303 (y) Observed, (2) 9°5384 9°5886 9°7949 10'0470 10°2825 10°5977 10°6250 10°6209 10°5167 10°3443 10°15 38 9°9977 9°9431 9°9840 10°'1621 10°3586 10°5702 10°6626 10°6673 10°5408 10°3461 IO°II40 g'8042 9°6034 (y—¢) Observed. (2) 5°2795 8°2397 12°3143 15°4591 16°4382 15°9041 14'0634 11°3496 8°5289 61519 4°5841 4°1516 52461 8°1588 12'2178 15°3410 16°4160 15°9342 14°1451 11°4566 86019 61441 4°5446 41112 Difference. ()-(@) —0'0048 +0'0058 —0'0039 —0'0003 +0'0047 —0'0064 +0°0050 —o°ooI2 —o'0019 -- 0°0040 —0'0037 +0°0023 —0°0023 +0'0042 —0°0082 +o'ollg —0'0130 +0°0103 —0°0037 —0°0035 -+0°00g91 —0°'0099 +0'0065 —0°0004. eT, Difference. (1)—(2) —o'or21 0"0000 +o'o0122 —0°0205 +0'0227 —0°0183 +o'oIo2 » —0"0022 —0°0042°— +0°0069 | —0'0076 +0°0071 —0'0063 +0°0045 —O°0017 —0°0034 +o'co8r —o'0122, +0'0117 — 00062 —0°0032, +o0'0129 —0'0197 +o'o191 TIDAL OBSERVATIONS. 867 (y—io+2a) (y—20) 5 ~~ ee ee teresa Calculated. Observed, Difference. Calculated. Observed. Difference, (1) (2) (1)—(2) (1) (2) (1)—() 10°9849 10°9688 +o'o161 98166 9'8427 —o'o261 10°5 382 10°5 528 —o'0i46 9°8354 9°8278 -0°0076 10°01 46 10°0059 +0'0087 9°9348 9°9300 +0'0048 9°4882 9'4898 —o'0016 10'0573 10'0630 —0°0057 * 91314 9°1350 —0'0036 10°1567 I0"'1549 +0'0018 Q°lI41 g'1095 +0'0046 10°2547 10'2565 —o'0018 9°3896 9°3920 —0°0024. 10°3529 10°3448 -fo'0081 98195 9'3203 —0'0008 10°4.185 10°4312 —0°OI27 10°3658 10°3630 +0:0028 10°4357 10°4260 -+0°0097 10'9264 10°9284, —0'0020 10°4499 10°4515 —0'0016 11°2698 11I'2707 —0'0009 1074696 10°4704, —0°0008 11°2642 11°2602 -++0'0040 10°4270 10°4348 —0°'0078 10°9573 10°9627 —0'0054. 10°3790 10°3569 +o'0221 ~ 10°4766 10°4723 +0'0043 Io"4114, 10°4.368 —0'°0254. 9°9446 9°9460 —o'ool4 10°4014 10°3937 -+-0°0077 9°4472 9°4479 —0'0007 IO°3101 10'2850 +0'0251 91166 9°1163 +0'0003 10'2987 10°3500 —0'0513 g9°1059 g°1028 +0°0031 10°3189 10°2643 +0'0546 9°3910 9°3987 —0'0077 10°2291 10°2642 —0'0351 9°8357 9°8248 +oro109 10°1271 10°1163 -+-o°0108 10°33 34. 10°3934. —o*0I00 10°0589 10'0606 —o°'0017 10°9362 10°9320 +0'0042 9°9363 9°9238 +o0°0125 11'2746 II‘2701 +0°004.5 9°8322 9°8620 —0'0298 112714 11'2833 —O°olig 9°8190 9°7823 +0'0367 21. In the averages for any one of the S, K, L, M, N, O, &c. tides ex- plained above, the influence of each of the others is nearly eliminated because of the greatness of the number of periods (roughly 360 and 720) of each in . the series of observed heights included in the summations. The choice of the approximate period 3694 3", as explained above ($17), makes as little as TABLE OF ComPARATIVE Mzan Sorar anv Mran Lunar Hovrs. Hour M (y—«). s{4a|s|el7|8]> |rofx 15 16| 17 | 18] 19 16/14/16) 13) 316) 14 }17] 15] 16]} 16/16) 17/15/17\ 45/17) 15| 17|14/16|14|151 15] 14 15/15|15)15|}314)15 | 15) 16) 35) 37|15| 17| 16/16) 16/16) 16) 16) 16) 14 | 16) 14 | 16| 14 13) 16/14)15/15)14 |16| 14) 16} 15|17| 15|17\ 15) 17]15|16] 17\|15|17 | 14| 16 | 14| 16 15/}14}15\14/16/14 |15] 15] 15) 16|15/ 16/16) 16/16/16) 15] 17] 16/16 | 16) 15 | 16] 14 14.) 16/13) 16/14] 16 | 13| 16} 14] 16/15] 15/37/15] 27/15/17|] 15} 17| 15 | 17] 15 | 16 15 15)15/15 |} 14/16) 34 | 15) 14) 15]15)15| 15] 16|16/16)17/ 15] 17/15|16 | 16/16] 15] 16 16/14}16) 14) 15/15 | 14| 16) 13} 16] 314] 16/14) 17/15/17] 16| 16/16] 15 17] 35 | 17| 15 14}15/14/15 [15) 15/15/14) 16| 14) 16) 14] 16)16)16| 16/16] 16 | 16|17 | 15] 17 16) 15/16 | 14} 16) 13 | 16) 14) 16) 14/35] 15} 15|15|14\ 17] 15| 17|15|17|15]17 | 16| 16 16/16} 16| 16/14/16 | 13] 16} 14] 15} 14| 15] 15/15] 35]15}17] 15!317|15 | 17 15 |16|16 15)17)15)17)15|15 | 15] 14) 15]14| 16] 13} 16/14] 16} 14] 16| 16/16/16 | 15] 17 | 15] 17 17) 1537 )15)17| 314 | 15) 15] 14] 16) 14) 16] 13] 16) 14/16) 13| 16) 16) 16) 17/15 | 17]\ 15 16|16/16) 16/15] 17 | 34] 16}14]) 15} 15] 15] 15|14]} 15/15] 15| 13} 17] 15 |17| 16 | 16| 16 15/16/17) 15|17} 15 | 17] 14] 16/13) 16) 14] 15] 15] 14] 16] 14] 16/13] 17/15] 17 | 15| 17 14 17/15/17) 16) 16|.16 | 16) 16) 15/15/14) 15) 14} 16/14] 15] 15) 15|15| 14 | 16/16] 16/15 TS5 | 15/37/15) 17) 15) 17 [15 | 16) 17] 14] 16| 13) 16) 14) 16/13] 16| 14} 16/14 134] 37 | 15] 17 16 | 17/15/17) 15) 16) 16 | 16) 15) 17) 36/15] 15} 14/16/14.) 15] 14] 25] 14] 16 | 14] 15 | 16| 16 17 |37/16)15/17|)315] 17 )15] 317] 15) 37/15 | 16/14] 15|15|14] 16] 13| 16| 14 | 16 13 [16] 15 18 | 16/16/16) 16} 16) 16} 17) 15) 17) 15/16] 16) 15}14] 15] 315/75] 15|14| 16 | 14| 16 13/15 19 | 16/35)17)15|}17|15 |17| 16) 16] 16/15) 17} 15|}16]13}16]14| 16| 14 15 |15|14|16| 13 20 14|16)15|}17/15| 16 |16| 16| 16] 16/16] 16/17/15] 16/13} 16] 14} 15| 14 | 15 15 [15|15 920 | 14) 15)15/ 16) 16) 15 | 17} 15} 47) 35] 17| 15) 17) 16/16] 15) 14] 15} 14] 16/13] 16] 14] 16 22 | 16/13) 15] 15) 316) 17) 15) 17\ 15] 17) 15| 17} 15|16] 16/16] 15) 14/16] 14 | 16 13 | 16] 14 23 | 14/16/13] 16/14/17 | 16| 16| 16/16} 16| 16/16} 15]17| 15/17 I5(IS5(15 {15/35 | 14] 15 Hour § (—71) 21 r|2 12 20 22 13 | 14 23 — Se WwW PH OM CN AnPW HHO _ wy Lal a 368 REPORT—1872. possible of the mutual influence of the two largest tides, the lunar and solar semidiurnal tides, in the two averagings performed to determine these two tides. But the incommensurability of the periods renders it impossible to al- together escape, in the direct synthesis for any one tide, the influence of the others. Accordingly, the coefficients A,, B,, &c., shown above, are to be regarded as first approximations in the mathematical solution of the problem. The next step followed was to find corrections upon each summation for the influence of the tides determined by the other summations, these corrections, for a second approximation, being calculated on the supposition that the first approximate values of A,, B,, A,, &c., already found, are correct. Auxiliary Tables for performing this process have been formed for use along with the other Tables (one being given as a specimen, p. 367) ; but the ultimate correc- tions found from them, after very considerable labour, affected the terms which represent genuine tide-components in so small a degree that their use has since been discontinued. The 8, K, L, M,N, and O tides for Ramsgate, 1864, were, however, so corrected, and the corrections thus formed are here given. 22. The corrections are to be subtracted from the values of A,, B,, A,, &e., to first approximation, and are as follow :— Table of Corrections of the 6 x 16 Coefficients A,, B,, ce. 8 K L M N i) (y—n) (y) (y-30-4~) (y-2) (y-4e+3~) (y—20) AS —"0025 —"0002 —"0021 +:0087 —'olsr —'0032 B, + '0015 -+'0001 —"0050 —'0003 +'0032 +°0056 A, —‘0018 —'0313 +'0065 —"0009 +'0093 —'o1388 B, —"o104 +0105 —'0338 +:0033 +ro101 —*‘o008 A, +'0009 +0087 —'0074. —'0025 —‘Oool —'0063 B, —"0004. —"0074 +'0152 —*oo15 +°0044 +'0032 A, _—"0005 +'0043 +0067 — ooo! +0015 —*0046 B, —"0013 +:'0026 —"oo4t —"'0013 +:0016 —"0003 A, +0105 — ‘olor +'0037 -++'0009 —"0052 +0024 B, —"o184 +°0075 +*0020 —"ool4 +0088 —"olog A, —'o198 +*oo12 —‘ooll —*0007 —*o004. —*0097 B, —'0042 + "0009 +'0017 +°0017 —'0020 — ‘0067 A, —*0030 +'0039 —'O145 —"0002 +0021 +0086 B, —"0035 +0042 +0014 —‘oolo —"003I —'0103 A, "0002 — ‘0009 — ‘0431 +°0005 +0008 -+°0029 B, +0001 +0064 +'0362 —"ool4 —‘oolo —'0030 Values of A,, B,, A,, &c., to second Approximation. 8 K L M N O (y-n) (y) (y-de-2%) (7-9) (y—-Be+3-m) (y—2c) Ay +0°0256 —0'2050 —0'0284 -+0°0136 +0°0332 —0'2931 B, —0'0270 —0'0237 —0°0070 —0°0055 +0'0016 +0'0631 A, +1°5616 —0'4227 —0°2341 —4°3167 +0°8098 —0o'0716 B, +1°0027 —o'0166 +0°3007 +4°5004 —0°7443 -+-o'0001 A, +0'0077 — 00050 —0°0022 —o'oll3 —0'0007 —0'0010 B, -+0'0008 -+0'0089 —0°0059 +0°0423 +0°0067 +0'0046 A, -+0'0300 —o‘oI70 — 070524 —0°5442 —o'olog +-0'0076 B, +:0'0022 --0'0047 —0'0886 —o'0865 —0'0138 +0°0037 A; —o'o105 --o°0050 —o*'o006o +0'0023 -+0'0039 —0'0002, B, +0'0213 —0'0003 -+0'0026 +0°0033 — 00036 +0°0035 A, +:0'0215 —0'0020 —0'0039 —Oo'l125 —0'0283 ++0'0035 B, +o'o110 -+o'0018 —o0'0096 —O'1131 — 070004, -+-0°0107 A, +0°0038 —0'0009 +0'0089 -+ 070023 —0°0043 +o'0116 B, +o'0081 —0°0053 +0°0029 —0'002I +0'0027 +o'0019 Ag --0°0009 +0'0067 -+-o*0010 --0"0290 -0°0040 —o0'0086 B, +0°'0027 —0°0097 —0'0050 — 00402 -+0°0009 +0'0103 Ay 10°1988 10°1989 10°1843 101992 10'1853 IO'I971 TIDAL OBSERVATIONS. 869 23. The values A,, B, in columns S and M express the mean solar semi- diurnal and mean lunar semidiurnal tides. A,, B, of column K express the luni-solar declinational semidiurnal tide. A,, B, of columns L and N express two constituents of the lunar elliptic semidiurnal tide. A,, B, of column O express zero tolerably well*. A,, B, of columns K and O express the two constituents of the lunar diurnal tide. ibe B, of column § express one constituent of the solar elliptic diurnal tide. Ay B, of column M express one constituent of the lunar elliptic diurnal tide}. A,, B, of columns IL and N possibly depend on the elliptic lunar diurnal tides, but will no doubt be found a better approximation to zero when cal- culated by the average of several years. There is no tide corresponding strictly to them. A,, B, are, as they ought to be, very good approximations to zero in all the columns except M. Their values in this column constitute, probably, a genuine expression of the terdiurnal lunar tide [not included in the pre- ceding general schedule (§ 3) but referred to in § 4], investigated by Laplace as depending on the fourth power of the moon’s parallax, A,, B, express shallow-water tidest derived from the lunar semidiurnal tide, according to precisely the same dynamical principle as that by which Helmholtz has explained the overtones generated in yery loud sounds, even when the source of the sound is a simple harmonic motion. There ought to be no sensible tide expressed by A, and B, in column L; and the comparative largeness of these numbers is probably an accident, owing either to errors of observation or the imperfection of the system of combination adopted, or a chance concurrence of disturbance due to wind &c. A., B, in almost every column approximate remarkably well to zero; and even their greatest values (those of column 8) express merely a deviation of =, of a foot (or 0-3 of an inch) on each side of the mean level. A,, B, may be considered as insensible for every column except M, for which they express, as they ought to do, an undoubtedly genuine shallow- water tide, being the second harmonic (as it were overtone) of the lunar semidiurnal tide. A., B, are very good approximations to zero in all the columns. A,, B, in column M express probably a genuine, though very small, shallow-water tide, the third harmonic of the lunar semidiurnal tide. There is a very good approximation to zero in all of the other columns, It is interesting, with reference to the mode of reduction which has been adopted, to remark to how nearly zero the comparatively large values of A, B, in column O and A,, B, in column L of the first approximation are re- duced by the corrections found in the second approximation explained above, _ 24. Selecting from the preceding Table the coefficients, which are each probably a genuine tide, and applying the proper corrections (Everett, Roy. Soc, Edin. Trans. 1860), which are the following :— * There being no theoretical tide of the period corresponding to them. + Being the resultant of the two whose speeds are y—-o+wa and y—o—w, inasmuch as for a single year the effect of the -+w may be neglected. t It is this term that makes the whole resultant tide rise faster than it falls, as is generally observed in estuaries and other localities separated from the oceans by consider- able spaces of shallow water. 2 2¢ me 370 REPORT—1872. Augmenting factor. A,, B, "0028 A,, B, OIIS A,, B, "02.62. A,, B, "0472 A,, B, ‘1107 A,, Bs "2092 to take account of the circumstance that the mean height for each hour has been taken virtually for the height at the middle of the hour, we find cor- rected values for the coefficients (A, B), from which we have the following amplitudes and epochs, according to notation of § 3:— Ramsgate, 1864, 8 K L M N O (yn) () (y-3e-3@) (y-0) (y—$04+3@) (y—20) A 00373 Or2670 | PEs O'OT4 5 Sacpor 0°3008 €, 313°°48 TB6°Gom, . lew: CL) had: | eee me der Gre 167°°85 R, 1°8772 0'4279 0°3856 6°3078 aRI26y 5) Sitter €, 32°97 182°°25 127°°90 133°°8r CUT fe. Oe reset Ee ad aa: cxeaecore © dy Peaeae dd” Piast FOAMS 5 AAT cetiaks! Eopeneretes Gx PS iG abt.c ee oc Ee: LOAR IGG.) Ooo c.teie . R, CREEL Wheat Oanecene Ma Met inch C5770 i. Wretgits onsite €; Be TOM a asenseNDt , esinte 189°°03 See tal PEL, So. R, SHORTT G Taelad -terieis) ila tee: ONF7L ie cp leathin fet aeeer €, 27°°04 Foss VOT Ries 225°°%4 Bee OOM As 3 GEE Oe ais, Hoc 0°0599 eiaite “house Ere (iitasveess 10 Set eric! elk ROGUES He ees eT eas 25. The hour-angles of the ideal stars having been assumed to be each equal to zero at the commencement of the observations, the previously found epochs (e,, e,, &c.) have to be corrected for this assumption in order that the tide-components may be referred to the true positions of the ideal stars. The correction to be added to the epoch of the diurnal tides will be equal to the true hour-angle of the ideal star at the commencement of the observations. In the semidiurnal the correction will be equal to twice the hour-angle, for the terdiurnal three times, and so on. The longitudes of the sun and moon and of the lunar perigee used in getting the true hour- angles will necessarily be their mean longitudes. In addition to the above six series, others have since been analyzed and included in the schedule. The amplitudes and the corrected epochs of the whole are as follow :— Yr. 1864. A,=10'1988 ft. Average inclination of moon’s orbit to earth’s equator (IT) =20°°3, 8 M L N MS 2SM 3MSs (yn) (ye) (y-40—43.@)(y—40+4-@)(y—40—4)(y + 0—29)(y—B0+4n) WP HORNS nee. 5 Latins coe ie ao en at pst CN Sc EY? Sig Sasi ae, eT chy ale, 0 ES CURE OT Se Oe rn R, 1°8772 63078 03856 DMI DG!, MPa Ne. es tga eee €2 32°70 339°°43 «-186°-28 BOS? ak! Pe eee: 263°°o2 andides eta Biavoag O:044 8" Ras MORE aie em lett OPE ES Gy edie Sao ao ls Miner ew RO ec ssn oo beaters 53906 R, O°OBTS Ors 77 ty Se eetam eon dette 824940. G aS eapes 00276 76, Ao TO; BAO Ge ts scsas an es mee Cog is (hen veter 335°°03 i, ofoz68 Mocaig7ir 22 Aiaka a tea ware et mela ull eet re a ay el SY tous toe Taig ahh tneTenye, aig hic all aeaen el I eany ates SS LLC |S leant act ce Mec bain ia Mi init «latin mcr Ewes « on a0c6 TIDAL OBSERVATIONS. 371 K ) Bo boheme dsndorgis | ‘pp or 2MS 8 Ga2e) G89) (yates yl Ge $e Hern) (y=20+n) R, 0°2070 0°3008 Boy Fes On ate ho PP RINT s | 100°'75 99°°34 2Ga°53 «rage BR Pert ot Nese R, OMaIgG TOR Oi o'1785 0°3526 0'2639 5 MOPS Fei! celvaavadis Wl sviaas 169°'97 328°°05 83°°"79 26. In the determination of the long-period tides the mean height of the tide for each solar day, 7. e. the mean of the twenty-four hourly heights as originally taken from the diagram-sheets, must betaken. This will give 365 means in an ordinary year; in leay year the last mean must be disre- garded, the subsequent equations being adapted for only 365 means. It will be necessary to clear. the means thus obtained of all undue lunar in- fluence, inasmuch as the periods of the lunar tides are not commensurable with the solar twenty-four hours. In practice the tide-components evaluated from the series named, for brevity, M,N, and O are generally found to be the only ones which have any sensible effect. The necessary correction to be applied to these means, on account of the semidiurnal tides of M and N, is R, ., sin 12n eee 54” an is X cos (2nt—e,), and for the diurnal tide of O R, sin Le n 34 sin 4 where nt is the hour-angle bs is ideal star at the time corresponding to the mean of the times for which the heights have been given. If the observa- tions of the tide-heights have been commenced at noon, then the mean of the times for the first day will plete ate to 114 hours of that day. The values of (nt—e) for each ideal star (M, N, and 0) having been found for 113 hours of the first day, then the values for succeeding days will be found from those of the first day by addition of the respective daily variations of nf. The first part of the formula will form a constant for each tide, and the correc- tions are found by multiplying these constants into the cosines of the re- spective values of (nt—e). The mean height, minus the sum of these correc- tions, will give the purified mean for each day. The next step is to take the mean of the 365 purified daily means, and to subtract the purified daily mean of each day from the mean height thusfound. This will give 365 small differences (termed hereafter ch), and it is on these differences that the cal- culation for the long-period tides is based. 27. The yalue of ch for each day is assumed equal to the following formula ;— 5 8 (nt—e,), ch= Acos(s—a)i +Bsin(c—a)i + C cos 2ct -+D sin 2ct + C' cos 2(¢—)#+D' sin 2(6—n)é + E cos yt +F sin nt +G cos 2yt +H sin 2yf, in which A and B express the coefficients of the lunar monthly elliptic tide, ie, D “- f: lunar fortnightly declinational tide, oor, D' F “55 lunisolar synodic fortnightly tide, ie, E 5 solar annual elliptic tide, Res; H 3 iy solar semiannual declinational tide. 202 RE?PORT—1372. 372 The equations are solved by the method of least squares—thatis, the values of dh are multiplied by the respective values of cos (¢— a), sin (o—@)t, cos 2ot, sin Qat, &ec., and the products added together. nents of ten equations are thus formed. T Bas ipod, Qy as Se a3 pm ==) = & aoe Ss 8, sg oS Ad q 3 ai ~ a 9) mt wt o ao mption that the value of nt is 0?-0 The following formule haye been calcu- lated, giving the values of the coefficients for the ri constant for each year—that is, on the assu the equations on the above assumption :— at the commencement of the year. ght-hand components of "H 4S.zg1+ 00.0 + 700.0 +7 00.0 +,¢ £2.0 "FI 00.0 “FI 00.0 “TI 00.0 "yy £z.0 ‘H $2.0 *y 41.0 *H{ 61.0 *H 69.0 "HT 69.0 +4 ¢.zg1+ 700.0 +q FI.0 +49 00.0 +9 t1.0 —plzt —bHoL.1 — 90. —pis.1 +4 33.8 —4 96.4 + 7 £5.z7g1-+ 00.0 —q 42. +,q 01.0 +a fb.zg1+,q $z.£ —q 46.0 +,q $2.0 —, 26.0 +,q 40.1 +,q %0.5 —,0 £z.0 +,90L1 —,Q 11.0 +10 89-1 +,@ 18-1gt+,9 £6.0 —q 41.0 —q 90. — (J 30.0 —q $0.£ +q $4.0 +,9 61.£g1+q 76.0 —,9 76.0 +,9 19.0 +,9 06. +,9 4L.0 —¢ 61.0 + 918.1 —9 01.0 +9 0S.1 —(— 6.0 +9 19.0 + 78-181 +9 83.0 + 88-0 —qzo.r +09 $1.4 —g 69.0 —@ 83.-£ —qtt.o —gq og.t +q Lo.r +g 06. +g 70.1 +0 g1.fgit+g $r.¥ +y 69.0 +y 96.¢ +y ?£.0 +YV 83-+ +yY t0.S —y LL.o +y 62+ —y tZ.o —gq $6.1g1+y 41.2 glu sca: yg glz us: yg %% POS ghz soo° Wook ple us * YQ, 0 ioe + =9(l—o)e us y9, YS + =9(l—2)z 800 * 9, por WIS" 40,00 97 809° Yo += 7(~—0) us° roe +Q6z-% +98L0 +g rz + So.£gr+=7(m—s) 800° 49 Oz TIDAL OBSERVATIONS. 373 28. These cquations, solved by successive approximations, give the follow- ing values of the coefficients for Ramsgate, 1864 :— ft. a at Wecsce the coefficients for the lunar monthly tide (elliptic). R= 00316 e=6978. Mi Staal the coefficients for the lunar fortnightly tide (declinational), R= 070331 c= 56°83. = ee } the coefficients for the lunisolar fortnightly shallow-water tide (syncdic). R= o'og60 e=211"93. . mae 367 } the coefficients for the solar annual tide (elliptic and meteorological). R= o1270 €=253° 20. G =+0'022 5 the coefficients for the solar semiannual tide (declinational and meteoro- H =+0'0713 logical ?). R= 00748 ¢€=72° 48. 29. The epochs of these long-period tides have also to be corrected on account of their phases having been each assumed equal to zero at the com- mencement of the observations, or, more strictly, at the time corresponding to the mean of the first twenty-four hourly observations. The amplitudes require no augmentation. The amplitudes and corrected epochs are as follow :— Long-period Tides. Speed ...... (o—m) 20 2(¢—n) n 2n ft. ft. ft. ft. ft. R 070316 0°0331 00960 0°1270 0'0748 € 45°09 268° 29 207°°85 180° 97 288°02 The reduction of the Ramsgate observations, so far as at present discussed, consists in the analysis of the year 1864 only. 30. A series of tide-records, taken near the entrance of the George’s Docks, Liverpool, has been supplied, on application, by the kindness of the Board of the Mersey Dock Estate. The heights through about twelve hours each, during a few interruptions in the tide-curve (caused by the accidental stopping of the clock &c.), have been inferred from the tide-diagrams of the self-registering tide-gauge at Helbre Island, at the mouth of the Dee. The following years have been selected and analyzed in a manner quite similar to that previously described for Ramsgate. It should have been stated that the epochs of the tide-components for Ramsgate, Liverpool, and also for Portland Breakwater, hereafter described, have been referred to the meridian of Greenwich, Greenwich mean time having been used in the records of the observations. 31. Liverpool (Lat. 53° 40! N., Long. 04 20™ W. of Greenwich). Year ... 1857-58. 1858-59, 1859-60. 1866-67. 1867-68. 1868-69. 1869-70. ft. ft. ft. ft. ft. ft. ft. A,= 167192 16°8208 168289 168998 17°0862 =317°4877 =—-17"1350 i= 2.8°°5 27°°9 27°%Oo 18° 4 18°4 19°°3 20°°6 * Tis the average inclination of the Moon’s orbit to the Earth’s equator, or the rean maximum declination, for the period. 1857-58, 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. REPORT—1872. 8. Speed of semidiurnal 2(y—7). 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. 0°0453 00696 070844 0°0470 0°0349 0°0399 69°°93 59°°78 56°°55 39°04 = 66°18 = 10128 3°2149 3°3124 3°1938 3°1304 370990 31217 11°78 Lr-12, 10°'08 11°°63 11°°31 11°88 070612 . 9'0600 0'0476 0°0475 00678 0°0640 322923 - 330°%8 = 294973314320 327°Kr =—-298°"49 M. Speed of semidiurnal 2(y—o). $$ — orolg2 0°0626 0°0092 0°0396 o°01g4 00603 3320719 266°°69 799:27 358°:02 259°°28 322°°82 9°6745 9°8124 9°8930 10°2713 10°2648 IO°I210 326°10 = 32545 «= 323°99 «= 325955 = 32695 = 3289-38 O°1053 070984. O°1525 00862 "1022 o'1158 330°60 = 315%04 = 321% 7T = 335927 ©=— 327943 324°°76 0°6847 0°6573 0°6371 07648 0°7238 o"7018 220534) 217>-68 221°°30 224°°19 2220550 223°°68 o'1812 01887 0°2093 02057 0°1936 01888 342976 348S2n = 343%I7 = 343980 = 348% 52 -353°OK 0°0582 0'0808 00658 0°0667 0°0670 00665 262938 = 278917 259°°39 282°09 280°89 295°°60 MS. Speed (4y—2c0—2n). — - = —— a ee eed 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. _ 1868-69. 0°4379 0°3488 0°3879 0°4635 0°41 53 0"4080 270°°68 265°°36 270° 49 269° 45 271°°86 269915 28M. Speed 2(y+-o—2n). 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. 01346 O°1595 0°1466 0°1390 01163 o°1402 206° 12 216°°66 229°°57 222°°06 224°'05 224°°11 3MS. Speed (4y—60+2n). ————————e —$—$__—__~.. - 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. (0°0063 _ 0°0212 .o'0185 070210 00313 0'0495 193°°37 52°16 29°94 26°90 58°11 43°78 K. Speed of semidiurnal (2y). HM 1857-58. _ 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. 0°3930 03978 0°3853 0°3278 02939 o°3116 283°°95 283°°08 273°°318 281°*60 289°°15 289° 46 r1$50 1°2742 170995 0°6336 o'7701 0°7346 5°°98 0° 40 349°°61 9°03 13°39 ; 12°°66 OQ. Speed (y—2s). — 1857-58. 1858-59. 1859-60. 1866-67. 1867-68, 1868-69, ©4419, 04136. | -_ 0'4519_. - .0°3058 02694 0°3374. 316°°69 °316°°28 318°°87 312° 74. 93087218 301°°88 a Eraye aries 1869-70. 0°0276 124.°°38 3°0516 13°°63 1869-70. 070841 Br 7 oEs 10°1443 329°°40 O'IO14 313°°23 0°7196 227°°87 02200 3°47 00770 293°°50 2 1869-70. O°3957 272°°96 SS 1869-70. 01206 233°°5! ”* 1869-70. O'0140 45°°20 an 1869-70. 0°34.04 - 293°°38 RS 1869-70, 0°3214 296°'29 : TIDAL OBSURVATIONS. 875 P. Speed (y—27). pit EE eS ale 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. 1869-70. R, 0°1250 0°1339 0°1306 o'1409 0°1357 0°1333 0°0935 6, 101°°96 105°°75 98°°6x 88°43 109°°17 84°21 77°08 L. Speed (2y—c—w). —- 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. 1869-70. R, 0°5069 0'7849 0°3459 o'6015 075842 0°5129 04671 4 -157°'93 168°'91 144°°S1 124°°08 Psi 50 159°°39 I51°°91 a N. Speed (2y—50+a). A____ pee es eee) ee 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. 1869-70. R, 18608 1'7607 1'9716 2'1608 Igi24 1°8307 1'8917 Ey 303°52 = 30872, 303998 = gor®"59 «= 30814 307°°39 —-305°"06 R. Sse (2y—n). Mm eee 2y—3n). 1857-58 & 1858-59. 1858-59 & 1859- 60. 1857-58 58 & 1858-59. “1858 59 & 1859-60. R, 0°1006 00818 0°3490 o'1208 ey 146° 45 146°'60 67°'97 36°'78 X. Speed Cr tear Pi carn ea a aE ee ee 1857-58. 1858-59. 1859-60. 1886. 67. 1867-68. 1868-69. 1869-70. R, o4091- 02262 . of1165 0'2369 0'2166 0'1977 O'Ig13 €, 141°°68 134.°°46 19°08 175°°95 180°'68 138°°54 132°°16 vy. Speed (2y—3c—m+2n),. fe = Se ae ee oa a a EN : 1857-58. 1858-59. 1859-60. 1866-67. 1867-68. 1868-69. 1869-70. R 0'7423 ° ~0°6303 o'2841 o°7182 o°5051 O°1423 o'6g12 € 307°°91 284° 01 261°'09 278°°43 267° 42, B11°'51 332°°41 pb, or 2MS. pad 2(y—2 o+7). a Se EN 1857-58. 1858-59. 1859-60. 1866 67. 1867-68. 1868-69, 1869-70. R, 0'2860 0'2259 0°3076 o'2561 02278 02576 0'2303 6, 31°72 42°°04 32°°55 32°°42 31°'94 64°20 39°°64 32, The analysis of the long-period tides of Liverpool has at present been limited to the first four of the seven selected years. The results are as follows :— Speed ...... (c—w) 26 2(¢—7) 7 2n 1851-58 { eS fe, eee ed aodee ae 1858-59. { = oie 148° oe Ong sani 269°-6 CS Rt nea BS ER EE Hiner FB S272 co) RHP ye BOER ho UE eho ares 876 REPORT—1872. 33. The agreements between the analyzed amplitudes and epochs for the whole of the short-period tides are, on the whole, satisfactory. ‘The chief discordances occur between the evaluated quantities of the lunar elliptic semidiurnal tides L, N,A, and vy. It is extremely probable that a period ex- tending through two entire years would give a much better agreement between these quantities, the period being more nearly commensurable with the majority of the chief tides, the period at present selected eliminating only that of the mean lunar semidiurnal (M) tide. The values of the mean sea-level show a general increase, although the value deduced for 1868-69 stands out prominently from those deduced for the preceding and following years. This uncertainty will affect sometimes, to a considerable amount, the prediction of tide-heights from a jfiwed datum, although such results are better and more intelligible than predictions reckoned from low water of ordinary spring-tides. 34. Through the kindness of Prof. J. E. Hilgard, of the United States Coast Survey Office, three years’ tidal observations, taken at Fort Point (lat. 37°67 N., long. 8"-15 W. of Greenwich), San Francisco Bay, California, were received and analyzed, with the following results :— Year ... 1858-59. 1859-60. 1860-61. ft. ft. ft. A,=8'7103 $2651 $°1608 TERS) 26°99 254 S. Speed of semidiurnal 2(y—7). M. Speed of semidiurnal 2(y—o). ——————— a a ens a ea 1868-69, 1869-70. 1870-71. 1868-69. 1869-70. 1870-71. R, 0°0703 0'0333 o°0714, R, 00173 070236 O°031I €, 269°'99 22.7°°72 304°°53 €, 216°°79 181°30 326°°55 R. Speed (2y—7). T. ses (2y—3n). SE SSS SSS 1868-69 and 1869-70. 1868- 69 and 1869-70. R, 0°0353 o'r108 6, 12°04 38°96 43. Long-period Tides. 1868-69. 1869-70. 1870-71. ft. ft. ft. ; “16 Srnec s ae O96 ee s ae be } Solar annual (elliptic) tide. Speed (7), R 0198 0°059 0'062 ) Solar semiannual (declinational) tide. € 81°98 116°'93 69°°69 Speed (27). R 0076 0°043 0°032 | Lunar monthly (elliptic) tide. 6“ 247°°73 175 27 115°90 Speed (s—w). R 0'038 0°064. 0°035 | Lunar fortnightly (declinational) tide. € 335°40 333°°91 283° 22 Speed (20). R 0°009 0°075 07058 ) Lunisolar synodic eae (shallow-water) € 32619 16°98 156°°62 tide. Speed 2(¢~—n) 44. The epochs are reckoned from the meridian of Kurrachee for the short- period tides, and for the long-period tides from the time when the respective argument of each tide equals 0°-0,—7. ¢. for the solar annual and semiannual tides from the mean vernal equinox, for the lunar monthly tide from the mean perigee, for the lunar fortnightly from the time when the moon’s mean longitude equals 0° and 180°, and for the synodic fortnightly from the mean new and full moons. 45. In addition to the foregoing reductions, a selection has been made from the tide-observations taken during the construction of the Portland Break- water, under the direction of Sir John Coode, from 1851 to 1871. The years selected for reduction were 1851 and 1871, being the first and last years of the observations at present taken, and the years 1857 and 1866, being the TIDAL OBSERVATIONS. 3881 years in which the moon’s declination had attained its maximum and mini- mum respectively. The peculiarity of the tide here gives rise to a consider- able number of important compound shallow-water tide-components, which has led indirectly to their evaluation at Liverpool and Ramsgate, through this clue to their probable existence having been found. It is probable that others besides those already found may exist, and of which a further exami- nation of the tide-curve may indicate their periods. The epochs of the tide- components are referred to the meridian of Greenwich, similarly to the pre- viously analyzed tides of Ramsgate and Liverpool. Portland Breakwater (Lat. 50°°5 N., Long. 9"°8 W. from Greenwich). S. Speed of semidiurnal 2(y—7). M. Speed of semidiurnal 2(y —c). a 4 a TES TAT a EAE Fe a Een 1851. 1857. 1866. 1870. 1851. 1857. 1866. 1870. ft. ft. ft. ft. =21°°6 285 18°5 2.2,9°2, A,=7°0766 7°0054. TI1I4 6:9860 ft. ft. ft. ft. R, 0'0742 070310 0°0255 o'0146 00178 0'0071 0'0348 0°0240 €, 83°85 97°°69 90°56 82°80 2449718 = 247954 = 9333972 «= 291°OR R, 10761 1'0757 T0903 T0551 2°1450 2°0271 1°9824. 20943 €, 243°°3I 2469764 244935 241°°39 195913 »=6-196957 194980 194.9'48 x ecedes 070300 070425 00481 002.64. Eo sonicol Rosco, ene eevee 174°°36 0 195%17 = 188%'10-S 1699°31 R, oo120 070096 00163 O°0104 04556 074.960 0°4725 0°4.680 €, 193914 18504 167958 196926 32°41 41°90 30°°07 32°90 Ta gcse eevee cc Moracerr 0'2217 O'1944 o'2178 0'2106 Picsaesey | ees . reeccon ane rere 73°°07 79°°36 67°°07 71°02 iy scence cen he MBtadece en enceer 0°0136 0°01 46 Orol12 0"0090 UE MGesai la | seses ooo rae cete PP eeeaee 61°70 45°78 38°°83 65°50 K. Speed of semidiurnal (2y). A Cg = ain ke SS Ses 1851. 1857. 1866. 1870. R, 0°2705 0°3245 0°2597 0°2995 rom 211°08 205°°55 202°°97 212° 9 R, c'2768 0°3854 0°2365 02590 €5 253°°95 243°°01 232012 252°°85 O. Speed (y—z2«). P. Speed (y—zy). ———— SS a Tah a a 1851. 1857. 1866. 1870. 1851. 1857. 1866. 1870. R, 071536 o'IgI9 O'1255 01605 0°0957 O'I179 0°1077 0° 1082 €, 249°°38 266954 9 =262%25 = -2519°77 20°82 18°09 14.°°67 17°64. L. Speed (2y—c—7@). N. Speed (2y—30+7a). eee —— —___ —— ———— — =. 1851. 1857. 1866. 1870. 1851. 1857. 1866. 1870. R, 0°2054 "1009 O1544 01723 0°47 34 04454 05182 04890 €, 33°39 © -299°73, 296954 2884318573 185966 = 85°85 = 18631 r. Speed (2y—-c+m—27). vy. Speed (2y—30—mw-+-2n). ee es St eS ee Sa a peqaetetan,) 1851. 1857. 1866. 1870. 1851. 1857. 1866. 1870. R, o1045 00560 0'0832 o'ogor 00950 0°1203 01248 071234 €, 29519 288969 © 314°%10 = 294%24 = 197% 77 = 11879 109°00 13692 oo28 REPORT—1872., por 2MS. Speed (2y—40-+427). 28M. Speed (2y+20—47). a ge EEN SS a a aE 1851, 1857. 1866. 1870. 1851. 1857. 1866. 1870. ft. ft. ft. ft. ft. ft. ft. ft. R, 0°3900 0°3719 0°3773 03756 O°0512 0°0687 0°0639 O'0512 €, 200°49 =6.199°°54 192980 = 1969-61 349°22 6°21 348942 © 34404 MS. Speed (47—20—2n). oMS. Speed (4y—60+27). a oN aa pe 1851. 1857. 1866. 1870. 1851. 1857. 1866. 1870. R, 02660 02655 0'2618 02831 0°0517 o'046r 0°0391 06263 € 88°15 9445 89%43 9326 = 132%1Q §=— 13562136974 = 134.°"50 —— 46. The complete. separation of the mean lunar and mean solar semi- diurnal tides in the foregoing analysis, together with the respective epochs of each tide, furnishes a ready means of finding the time of spring-tides or the time at which the two tides are exactly the same in phase. If we take, for instance, the respective epochs of these tides as given (§ 25) for Ramsgate, we find that the mean solar semidiurnal tide attains its maxi- mum when éwice the mean sun’s hour-angle, or angular distance from the meridian, is 32°70. Similarly the mean lunar semidiurnal tide attains its maximum when twice the mean moon’s hour-angle is 339°-43. Dividing the difference between these two epochs by twice the difference between their respective mean daily motions, we obtain an interval which represents the time at which the two tides are coincident after the two bodies were in conjunction. The difference between the mean daily motions of the moon and sun is 12191 per day. The result thus obtained for Ramsgate is 360°+4+382°-70—339°48 53°27 2x 12°191 : 249-389 = 2°185 days. 47. Treating the solar diurnal declinational tide (P) and the lunar diurnal declinational tide (O) in a similar way, we obtain the interval after the conjunction of the two bodies at which these tides are coincident in phase. Thus, for instance, we find ($ 25) for Ramsgate 262°-58—99°'34 — 163°-24 pee 8 eS = ‘695d v3. 2x 12-191 Baas 48. The lunar elliptic semidiurnal tides L and N, and the mean lunar semidiurnal tide M may also be similarly treated. The equilibrium theory gives h{eos aeons cos [2(y—e)t=g]— 5008 [2(y—o)i+¢]} for the sum of the mean lunar semidiurnal and lunar elliptic semidiurnal tides, where h denotes the semi-range of the mean lunar semidiurnal tide, e the excentricity of the moon’s orbit, and ¢ the longitude of the mean moon (M) reckoned from the perigee, or, astronomically speaking, the mean anomaly. We have $=(o—2) (=) TIDAL OBSERVATIONS. 883 if T denotes the time of perigee preceding ¢: and so the preceding becomes ~ h{eos Xy—a)t-+ > 008 [(2y—3a-+a)t+ (o—a)T] -- 5008 [(2Qy — e—a)i—(e—a) TI} or hf cos 2-y—o)t+ T o0s [Qy—8e+4+a)t+(o—a)T] +5 cos[(2y — e—v)t+180°—(o—)T]}, ss that t=T is the time of coincidence of the M and N tides, and the time of opposition of the M and L tides. Let R, cos{2(y—c)t—e,} +B, cos [(2y—30 4+ #)t—e,] —R,," cos [(Qy—ae—w)t—e,"+ 180°] be the expression for these constituents derived from observation. For the times of coincidence we have M and N observation, 2(y—e)t—e,=(2y—3e+7)t—e,;, ' cc -€ <8 2 Be giving i= auras and therefore the delay = 2a: o—-e similarly the delay of opposition of the M and L observed tides, after the opposition of the corresponding equilibrium tides, is e,"—-e, + 180° Ue Tf, however, the corrected epochs are used, the term T should be omitted. Thus for Ramsgate ($25) we haye for the delay of coincidence of phase between the M and N tides 339°43—310°31 29°12 13°-065 7 13°-065 = 2-229 days after the moon’s perigee ; and for the delay of opposition of phase between the M and L tides 186°-28 —339°43+1180° 26°85 j ae = 73°65 =2°056 days after the moon’s perigee The solar elliptic semidiurnal tides R and T may be referred in a similar manner to the mean solar semidiurnal tide (§). 49. It is here worthy of remark, that the larger (N) lunar elliptic semidiurnal equilibrium-tide (as indicated above) is seven times the value of the smaller component (L); but on reference to the foregoing results it will be found that the proportion between the actual components for _ English ports is about 34 to 1. The cause of this discrepance has not yet _ been discovered: as will ‘be seen subsequently ($51), the deduced value of the smaller component L is too large when compared with its equilibrium- 38 REPortT—1872. theoretical value for nearly all places. On the other hand, the equilibrium- theoretical ratio is fairly approximated to in the values found for Fort Point and Kurrachee. 50. The following Table exhibits the times of coincidence and opposition of phase of some of the chief tides. The values are deduced from the mean of the results when more than one year’s ‘observations have been analyzed. Coincidence Coincidence Coincidence Opposition of phase of of phase of of phase of — of phase of S and M P and O M and N M and L — = oe 8 ee After Moon’s Syzygies. After Moon’s Perigee. SS Se d d d d gles N., long. 0"-20 W. | ash50 5°796 Se igse Ramsgate. : 66 . 056 Lat. 51°-3 N., long. 0-09 E. amaS 95 va 2°05 Ae ae ee en Tat, 24°98, long. a7 w, $ FID (0353 5a eae Seta eae) a rs mare Fort Point (California). ‘ , ‘ Be Lat, 37°-67 a long, 815 w.} er Se i eRe meee Cat Island (Gulf of Mexico). \ Lat, 30°23 N., long. 5-94 W, j The sign — indicates that the phenomenon occurs Jefore the moon’s perigee. 0°535 0'260 —1°747 2°422 The following is the investigation of the formula for semidiurnal and semi- diurnal declinational tides :— Let YP and YS be the great circles in which a_ geocentric spherical surface is cut by the earth’s equator and by the plane of the orbit of sun or moon. When the moon is considered, Y will be approximately the first point of Aries. It is, of course, ag rigorously so for the sun. Drawing SN perpendicular to YP, we have SN=8, the declination. Let SyP=z, being the inclination of the orbit to the equator. Suppose now Q and P to be points of the equator in which it is cut by tlie meridian through the crests of the semidiurnal equilibrium tide, and the meridian through the place for which the equilibrium tide is to be expressed. If s denote the equilibrium semidiurnal variation of tide-height, we find readily, from § 808 (23) of Thomson and Tait’s ‘ Natural Philosophy’ s=C cos? / cos? 6 cos (2x QP), where - denotes a constant for each place. Take P’ so that PP’=QN, and join SP’, Ss TIDAL OBSERVATIONS. 885 ; We have But s=c cos? 0 cos (2X NP')=c cos? 0(2 cos? NP’—1). cos? d cos? NP’= cos? SP’ = (cos YS cos YP'+ sin YS sin YP’ cos 7)? 1— cos? cos (YP'-+-Y8) } ; ‘ = = { det cons cos (YP’—YS)+ 1+ cost)? 9 yo» sin? é Iyp/ ‘oy 1— cost)? 9 = =) cos? (VP —'8) +2! (cos! YP” — sin? 18) + (= 2%") cos? (x P'-+ 78) G 5 2 2 2 opis is <4 et ae a. =¥8)+- cos 2YP'-+ C=) eos 2(YP’+-YS) — sin? 5 . eae Pe ee i © . . «= a“ 2 ig ae aa ss =} — >) cos 2(P'~8) +" cos oyp'4(1 > ‘) cos 2(YP'+Y8S)+ cos? 3 | 2 Hence + \2 ae Sree s=c { ==) cos2(YP'’—YS) $y * cos 2YP’+ es) cos 2(YP’+-YS) } -(1) If time be reckoned from the transit of the first point of Aries across the meridian of P’, we have YyP'=yt when the formula is applied to the solar tide, and for the lunar YP'=yi—Q, where Q denotes the right ascension of the intersection of the moon’s orbit with the earth’s equator, from the first point of Aries. For the solar tide YS is the sun’s longitude, and for the lunar YS is equal to the moon’s longi- tude with a correction depending on 2. Hence, in the two cases respectively, we have YS=ntte+P, YS=ot+e'4+Q,. 6. - 2 se ees (2) where e, e’ denote the longitudes of the two bodies at the time =0, P the sun’s elliptic inequality of longitude, and Q the moon’s elliptic and incli- national inequality of longitude. For the mean semidiurnal and the decli- national semidiurnal tides we neglect these inequalities, and so find (Solar) #- { (ES) cos 2[(y—n)¢—e]+ sin? 2 © cos 2yt+ (=e) cos 2[(y-+n)t+e] } : | where w denotes the obliquity of the ecliptic, and | (Lunar) tme'{ ( pete *V'e08 OE ay elf : cos ayt ($4) vos BA(yta)t+e'] i. 2 2 Denoting by E, 8, M the masses of the earth, the sun, and the moon, by @, w' the parallaxes of the sun and moon, expressed in radial measure t [i.e. =F by a the earth’s radius, and by ? the latitude of the place, 2D « (3) 886 REPORT—1872. and neglecting the influence of land (Q, 33), we have [Thomson and Tait, $§ 808, (18), (23)] s ! a c= 55 wu cos!l and c= wa cos? U, ee ee ee a Using these and (2), with the notation of (3) in (1), we find oa ,f@mSr/l+cosw\? _.. ue ee sin? w stein eos { Fe (AS *) cos [2(y— )¢—2e—2P]+ 9 cos 2yt +(=$2") ‘cos [2(y-+n)¢-+26+22) | SM -/1-4 cos i\? sin? + (A) cos 2[(y—o)t-Q—c'—Q] + cos 2(y¢—Q) = 9 + (32%) cos 2i(y+o)e-9+6+Q)] } . -..« K/h ees) as the rigorous expression for the semidiurnal equilibrium tide-height, on the supposition of no dry land, or of such a distribution as to make A=O0 and 33=0. By taking the expressions given by physical astronomy for 7, P, =, 7, Q, and Q, and expanding in series of simple harmonic functions of the time, it is easy to obtain, in the form proper for the harmonic analysis, a complete expression for the whole astronomical semidiurnal tide-generating influence. -. 2 ies *\ 2 The terms of (3) or (5), containing the factors (==") and (= 9 ? are, on account of these factors, necessarily very small. They show semi- diurnal constituents with arguments 2(y+7)¢ (solar) and 2 (y+-c)t (lunar), which have not hitherto been investigated from observation, but which, for the case of the moon, and particularly in years when @ is large, may be quite sensible. 51. The Table on the opposite page exhibits the comparative values of the analyzed and equilibrium-theoretical semidiurnal tides referred to the mean lunar semidiurnal tide as unity. The epochs of all of these tides are expressed in hour-angles of mean solar time, and are referred to the meridian of the place, except for Liverpool, Ramsgate, and Portland Break- water, which are referred to the meridian of Greenwich. 52. The following will illustrate the method at present employed in the com- parison between the actual tide-heights as recorded and the heights as furnished by the evaluated tide-constants. The residual differences (which include instrumental errors of every description) show the amount of precision arrived at from the tide-components included in the analysis, and are useful as a guide for the introduction of new arguments and the consequent evalua- tion of new tide-components. The Tables are based on the analyzed values of the tide-components of Kurrachee for the year 1868-69 alone, excepting the R and T solar elliptic semidiurnal tides, which are the results of 1868_ 1869 and following year. Tn order to facilitate the computations of the heights, Tables showing the value of the tide above or below mean level for each 15° of hour-angle for the § tide should be formed, or for a less interval if it is contemplated com- puting the tide-heights for more frequent intervals than each integral mean solar hour, and for every degree of the M tide on account of the magni- tude of R, of this tide, and for every few degrees for the rest of the tide- components, 387 TIDAL OBSERVATIONS. 09.46 oZ1.0 $o.yO1 oL0.0 82-49 £07.0 OL.yII ZO1.0 91.48 Lz1.o $£.y0 0L0,0 60.40 060.0 eer Perret 00.49 Lz1.0 796.411 Di *[BUANIptutag yeuorjeurpeq avpostun'T Qz.46 S¥.qIl 600.0 $00.0 Of .yI 66.49 ¥¥0.0 ¥10.0 SLigt £3.01 £z0.0 600.0 00.19 00.10 gz0.0 Yoo.0 Sg10.y21 | 9£g96.q11 Ui a *[eUANTpLUTEG onda Aepog sence eaetene 00.40 gLt.0 0000.y71 8 ‘yeurnIp eS arog uveyt 66.42 pas 95.6 £z0.0 90.42 || bgr.o OO. z¥0.0 ov.yI 9Z0.0 eee eweeenee || ©0.40 770.0 n ‘TeumTp ps UOUDLD 4 || $tZQ.yZ1 a] eeeeee £9.yO1| ¥9-q11 gic.o | $10.0 $9.46 9745 gito.o 610.0 £6.yb 10. g$0.0 Fo.0 IS.yII| 8-qX1 90.0 370.0 €z.yor} z¥.yir £S0.0 £70.90 00.40 00.49 L£0,0 £00.0 O9Z9.y2T | YITT.yTI se X *jeurnIpiUeg wornszdyy Bly! Szz.0 89-yOr 177.0 VzyI §zz.0 06.,6 giz.o 5.49 ££z.0 16.y01 9Z1.0 VL.yOr 161.0 09.49 761.0 fF.q1 660.0 $7.11 0f£0.0 $£.40 £Lo.0 gb.yOr gz0.0 30.44 LLo.0 OZ.49 190.0 TT.yII +S0.0 eee 00.40 Lz0.0 $gS9.y2l | 9161.71 L£,,0 =UMUITXBUI Jo oUt], 000.1 7 oF.yIT = UMNUIXBU Jo OMIT, 000.1 1 So,y2 =WNUITXBUL JO OUT, 000.1 W £z.yOI =UWINUITXEIM Jo omary, 000.1 Y oL.y9 =UNUITXBUL FO OUT, 000.1 =Y 1Z.y1I =WNUIIXeU JO OUUTy, cool = UY ZZ.yI1 == WNUIXEU Jo OUT, *M F6-u9 “S00] “NT 86-008 “JI *(OO1xeyL JO FNH) purrs] yO | cy "M Cl-yQ"SU0T | A “N L9-0LE FI (eraroj BD MLO LOT “H 98uh “Su0T “N G6-081, ‘J@T “Lequiog “H L¥-yh “Buoy “NI G:0FG “FT “ea OVA “M 9Ieq0 “BUOT “NT G-00E 9PL “LOOM BOA pueyytog "H 60-y0 “SU0T “N Gol WL ‘ “aye ssmeyy *M 06-0 “SU0T “N OF-o89 '9°T 000. = YF 00,40 090.1 = UINUIIXRUT JO OWL, =a Yoder Geman ie ea gs N T W 5 le TREANEPIORe |S ond 1euny zwunT uray \. | | | -joodxoavy C14 T3= uns 0} WOOF) “senTeA yeoyeaoayy-uanraqiin bay seeeeeeeeeaseneesere® SNOTIOg 388 REPORT—1872, (1) §,—Solar Semidiurnal tide (including effect of solar elliptic diurnal). h=R, cos {(y—n)t—e} +R, cos {(2zy—n)t—e,} =0'072 cos {(y—n)t— 176°°57} +.0'932 cos {2(y—m)é— 322972} a b c d A B WV - (y—nyt (y—-n)t—-4 cosb exR, d+R, (frombelow) A+ " . ft. ft. ft. ft. fo) 183°43 —'998 —'072 “000 1°674. 1°674 15 198°43 —'949 —'0b9 "003 1'292 1°295 30 213°43 —°835 —‘obo O12 o'814 0°826 45 228°43 —*663 —'048 024 0°367 0°391 60 243°43 pea. — (032 “O40 0°073 O'113 75 258°43 — "201 —"ol4 058 0°007 0'065 90 273°43 +060 +'004. 076 o'I1g0 0266 105 233°43 +316 +'023 "095 0°572 0°667 120 3°3°43 +°551 +040 "112 1050 1°162 135 31843 +°748 +054 "126 1°497 1°623 150 33343 +°894 +064 *136 1791 1'927 165 348°43 +'980 +'071 "143 1°857 2°000 180 3°43 +'998 +:072 "144 1674. 1818 195 18°43 +'949 +'069 “141 1292 1'433 210 33°43 4+-°835 +'060 "132 o814 o'946 225 48°43 +°663 +048 "120 0°367 0°487 240 63°43 +°447 +032 “104, 0073 0177 255 73°43 +'201 +'014 “086 0°007 0093 270 93°43 —‘ob6o —"004 068 ©7190 0258 285 108°43 —*316 —'023 "049 0°572 0°621 300 123°43 —"551 —"040 032 1'050 1'082 315 133°43 — 748 —"054 "018 1°497 1515 330 153°43 — "894 —"064 "008 1°79! 1°799 345 168°43 —"980 —‘o7I "O01 1°857 1858 a b ¢c d B 2(y—n)é 2(y—n)t—e cos b cxR, d+R, » a ft. ft. ° 37°28 +°796 +°742 1°674 30 67°28 +°386 +°360 1'292 60 97°28 —"127 —'118 o814 go 127'28 —*606 —"565 0°367 120 157'28 —"922 —°859 0'073 150 187'28 —"992 —"925 0007 180 217°28 —'796 —"742 0*190 210 247°28 —*386 —"360 0'572 240 277°28 +°127 +118 1°050 270 307°28 +606 +°565 1'497 300 337°28 +'922 +°859 1'791 330 7°28 +°992 +°925 1°357 The values of R, and R, have been added to each value of h to make all the heights positive, and therefore the sum of R, and R,, or 1-004, will have to be subtracted in the calculations of the heights on account of these tides. Similarly, in the other Tables the value of R has in each case been added (except for the lunisolar diurnal and semidiurnal tides, for which tides 1-12 foot instead of 1:41 foot has been applied); the augmented values are indi- cated by the symbol 7’. Instead, therefore, of the mean height being added to the sum of the values of h’ in the formation of the tide-heights, the difference between the mean height and the sum of the whole of the tide-components is to be applied. Care should be taken, in reading off the tide-heights in the first instance, to choose a datum-line sufficiently low, in order to secure this difference being positive. Tables for the other tide-components have been similarly formed, and are here giyen ;— TIDAL OBSERVATIONS. 389 (2) M,—Lunar Semidiurnal (including elliptic diurnal, terdiurnal, &c.). h=o'018 cos{(y—o)f—271°60} +2°586 cos{2(y—o)f—295°°78 +0'044 cos} 3(y— o)t—335°18t+0°017 cos{4(y— o)t—47°'04 +0°044 cos} 6(y—o)f—225°91 : (y—o)t h' ft. ° 99 100 Iol 102 103 104 105 106 107 108 109 110 III 112 eee) 114 115 116 117 118 119 120 "03 "03 ‘of "06 “08 ‘10 *12 3°80 3°87 3°95 4°02 4°09 4°16 ° 120 “121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 133 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 (y—a)t h' ft 4°16 4°23 43° 4°36 4°43 4°49 455 4°61 4°66 4°72 4°77 4°82 4°87 491 4°96 5°00 5°04 5°97 5°10 5°14 5°16 5°19 5°21 5°23 5°24 5°26 3°78 (y—a)e h dia tis 180 3°78 181 3°69 182 3°61 183 3°52 184. 3°44 185 3°35 186 3°27 187 318 188 3°09 189 3°01 190 2°92 I9l 2°33 192 2°75 193 2°66 194 2°58 ag5 ero 196 241 197 2°32 198 2°24 199 2°16 200 2°08 201 2°00 202 I'g2 203 1°84 204. 1°76 205 1°68 206 1°61 207 1°53 208 1°46 209 1°39 210 1°32 21 1°25 212 1°18 213° «Il 214 1°05 215 "99 216 ‘92 217 86 218 81 219 °*75 220 ‘69 221 64 2226 “BG 2230055 224. °50 225 °45 226 ‘41 227, 36 228 89°34 229/035 2300 '28 230 25 bled, ele} 233 20 234. "18 235 ee 230K ness 237 «6°45 235. °I4 239.8 t+ 240 ‘I4 y-o)t h' ft. ° 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294. 295 296 297 298 299 3Cc0 "14 14 Moon’s max, dec. (1868 May to 1869 May)=19°'7. (y—o)t tte ° 300 301 302 393 34. 395 306 307 308 399 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 35° 351 352 353 354 355 356 357 358 359 360 4{IL 418 4°25 4°32 4°39 4°45 4°51 4°57 4°63 4°69 475 4°80 4°85 ae 495 499 5°04 5°97 5.11 5°15 518 5°21 eS 5°26 5°28 5°30 5°31 5°32 rg 5°33 5°33 5°33 5°32 5°31 5°30 5°28 5°26 5°24 5°21 518 5°14 5rI 5°97 5702 4°97 4°92 4°87 4°81 475 4°69 4°62 4°56 4°49 4°42 4°34 4°26 419 4cI 4°02 3°94 3°86 390 REPORT—1872, (3) K,—Lunisolar Diurnal and Semidiurnal (Declinational). h=1'167 cos{ yé—142°°87} +0'239 ft. cos{2yt—340°r25} © © O74! 2 9°43 4 0°45 6 0°47 3 0°49 IO O'S1 12 9°53 14 0555 16 0°56 18 0°58 20 o'60 22 0762 24 0°64 26 0°66 28 0°68 30 O71 GP 10°73 $4 275 36 077 38 0°79 4° o'81 42 084 44 0°86 46 0°89 48 o'91 ao) 204 32) 2°07 54 2°99 56 1°02 58 1°05 Go 108 (y—2c)é h’ . yt (y—20)¢ 1 h’ ft. 1:08 I'll 114, 1'l7 1'20 1°24. 1'27 1°30 1234- 1°37 1°41 145 1°48 1°52 1'56 1°60 1°63 1°67 qi 175 179 1°83 1°86 ft. yt h’ ft. 215 218 2°21 224 2°27 2°29 2°32 2°34 2°36 2°38 2°40 2°42 a43 244 2°45 2°46 2°46 2°46 2°46 2°46 2°46 245 2°44 2°43 2°41 2°39 2°37 2°35 yt ° 180 182 184 186 188 190 192 194 196 198 200 202 204. 206 208 210 212 214 216 218 220 222 224. 226 228 230 232 234 236 238 240 hh’ ft. 2°27 2°24, 2°21 217 2°13 2°09 2°05 2°01 1°96 1"92 1°37 1°82 1°77 I'72 1°67 1°61 1°56 1°50 145 1°39 1°34 1°28 1°22 Il7 vir 1°06 1‘00 0°95 089 0°84. 0°79 yt ° 240 242 244 246 248 250 252 254 256 258 abo 262 264 266 268 270 272 274 276 278 280 282 284 286 288 299 292 294 296 298 300 Lunar (Declinational) Diurnal, (4) 0. h=0'569 cos {(y-20)¢— 308°°37} (y—2o)t h' ay 8a I20 o‘'Oor HMA. PaasTo) 130. ‘00 359 voo 149 ‘oI Tee Wop 150 ‘04 155 06 160 ‘08 165 ‘Ir I7O.. °14. X75 ele 180 o'21 (y—20)¢ h' one: 180 o'21 Tey EAs Igo "29 195 34 200 °39 205 43 210 86— “48 Br5 peg 59 220 «°58 225 °63 230 86°68 eo IS 249 oki’ h! ft, °'79 0°74. 0°69 0°64. 9°59 0°55 o°5I 0°46 0742 0°38 0°35 o'31 0°28 o'24. 0°22 o'rg 0°16 O14 O12 [ob fo) 0708 0°06 0°05 Q'04, 0°03 0702 oO'ol 0'00 o*00 0°00 0700 (y—20)¢ h’ ° 240 245 250 255 260 265 270 275 280 285 290 295 300 tt. O77 82 86 “91 “94. 098 I‘or 104 1°07 1'09 D ae i 4 riz I'I3 0°00 0°00 "00 ool o'or 0702 0'03 0704 0°05 0°06 0°07 008 o'1o O'1l O13 O14 o'16 O17 org o'21 0°23 O24 026 0°28 0°30 0°32 0°34. 0°36 0°37 0°39 oy (y—20)t h' ° 300 305 310 315 320 325 33° 335 340 345 350 355 360 ft. 1°13 Il4. 114 erg I'l3 I'l2 I'lo 1'08 106 1°03 I‘oo 0°96 0°93 TIDAL OBSERVATIONS. 391 Solar (Declinational) Diurnal. (5) E- h=0'376 cos {(y—2m)¢—316°"35} (y—2n)t bh’ (y—-2n)t Wh (y—2n)t hi (yA WW (y—2n)t hh (y—2n)t Bh’ fi ft. ft. ft. ft. ° 3 fc) : ° p ° ° ° _ 0 0°65 60 029 120 0°02 180 o'lo 240 O47 300 0°74 5B 9°63 65 ‘26 L225 tor 185 "13 245 °50 30m 74: 10 = *60 7) bes23 130 © "00 190 "IS 250 53 310 °75 1s) ey 75°20 F355, “00 195 "18 255 °56 BIS 75 aq © 54 80 "17 140 "00 200 ‘21 260 6°58 B20). 175 Be. 2" 5r $5 osry, 145 ‘oo 205 Basza 265 ‘61 g25 “75 30 «6°48 go ‘12 150 ‘or 2190-27 270 «8664. 330 «= ‘74 35°45 95 "09 155 "02 215 "30 275 66 835. “73 4o 4 742 100 ‘07 160 ‘03 220) = 943 280 6°68 340 °72Z 45 39 105 06 165 *05 225 °37 285 °70 345 “72 50°35 110 "04 P71. "0G |. 230 7749 290 «‘7I 350 “69 SE eo TI5 103 175 08 235 °43 295° ons 355 67 60 o'29 120 Q'02 180 of10 240 0°47 300 0°74 360 0°65 Lunar Elliptic Semidiurnal. (6) L. h=o'080 cos {2(y—30—gw)t— 108°27} (y—4o—4w)é i (y—40—20)E Hi 5 a ft. 2 eS ft. ) 180 0°05 go 270 Orr 10 190 08 100 280 08 20 200 11 110 290 05 30 210 13 120 300 03 40 220 15 130 310 ‘Or 50 230 16 140 320 bee) 60 240 "16 150 330 ‘oo 79 250 “I5 160 340 ‘OI 80 260 "13 170 350 03 go 279 O'lr 180 360 0°05 (7) N. h=o'622 cos {2(y— 36+ 3w)t—280°31 (y-iotiw)t BW (y-dotdo)t Wo (y-fotiw)t h (y~hotew)t hi ee fh. Cpe eee ft. ft. O° fe} oO ° ° © 180 073 46 226 o‘or 90 270 O'51 536° 446 1:24) 2 182 *69 48 228 ole) Q2 272 0°55 138 318 = 1°24 4 184 *65 50 230 "00 94 274 0°60 140 320 1°24 6 186 *60 52 232 "00 96 276 064 142) 922) 1°24. 8 1388 *56 54 234 ‘OI 98 278 068 I44. 324 1°A4 Io 190 “52 56 236 ‘OI 100 280 0°73 146 326 8 1:23 20 TQZ “48 58 238 raz 102 282 077 148 328 1°22 14 194 "43 60 240 04 Io4. 284 o'81 150 330 1°21 16 196 *39 62 242 "05 106 286 80°85 152. 332 1'IQ 18 198 rain 64 244 ‘O7 1c8 288 o'89 054 334 127 20 200 “4a 66 246 "09 IIO 290 0'93 156 336 415 22 202 28 68 248 252) II2 292 0°97 158 338 1°13 24 204 24 70 250 ‘IA IIA 294 + 1°00 160 340 = #©1'IO 26 206 *21 7 OLY: oz 116 296 81°04. 162 342 ro7 28 208 "18 74 254 "20 118 298 1°07 164 344 1°04 30 210 15 76 256 24 120 300 81°10 166 346 ror ae) 212 pie> 738 258 to P22 RO2 ke ke, 168 348 0'97 34 214 "10 80 260 “31 124 304 I°15 170 350 0°94 36 216 *08 82 262 35 126 306 1°17 172 352 0°90 38 218 "06 84 264 39 1z8) Jos 7 X°19 174 354 0°86 40 220 *O4 86 266 "43 130/300 | 5-21 176 356 o'82 42 222 03 83 268 °A7 132 312 1°22 178 358 077 44. 224 ‘ol go 270 OSI 194° 314. “123 180 360 0°73 46 226 oro! 136 316 8=1°44 892 REPORT—1872. Lunisolar Semidiurnal {(Hvection) and ( Variation)}. (8) 2. (9) ». h=0'061 cos RE i h=0'196 cos {2(y—$0—}w+n)t —156°°46 a NO) (y-40+30—n)t h' 2§5°°63} 2 A ft. ° 180 ool 10 190 "02 20 200 03 (y—f0-—30+)t h’ 30-210 "05 af * ft. 40 220 *08 ° 180 O's 50 230 "10 5 185 “12 60 240 Ir 10 190 "09 70 250 "12 15 195 *06 80 260 "12 20 200 "04 go 270 12 25 205 "02 100 280 ‘Ir 30 210 ‘Or IIo 290 "09 35 215 ‘00 120 300 ‘O7 40 220 "00 130 310 "05 45 225 ‘OI 140 320 03 50 230 *O2 150 330 ‘or. 55 235 <3 160 340 “00 60 240 *06 170 350 “00 65 245 08 180 360 o'or 70 250 ‘II 2 SS ae ce) 260 oi (10) p. 85 265 ‘21 h=0'070 cos {2(y-20+4 aa ‘99} go 270 "25 (y—20+n)t 95 275 28 5 ee 100 280 ett ° 180 0°07 105 285 "33 10 190 C5 110 290 "36 20 200 03 115 295 37 30 210 ‘OI 120 300 39 40 220 ‘00 125 305 39 50 230 ere) 130 310 “39 60 240 op | 135 315 oo, vic) 250 03 140 320 "38 80 260 "05 145 325 *36 9° 270 °O7 150 33° 34 1co 280 "09 155 335 “31 110 290 12 160 34° 28 120 300 ong 165 345 "25 130 310 14 170 350 22 140 320 "14 175" . 8255 "18 150 330 13 180 360 O°15 160 340 12 170 350 ‘og 180 360 0°07 Lunar Elliptic Diurnal. (11) J. (12) Q. h= = 0'080 cos {(y-+-o—w)t—-178°° 58} h=or1r1 cosf (y—30-+-w)t— 308°23% (y+o-—mw)t hi’ (yto-—w)t i’ (y—30+m)t W’ (y—30+m)t h’ a ft. eS ft. = ft. cits ° 0°00 180 o'16 ° o18 189 "04 20 "OI 2co 15 20 "15 200 “08 40 "02 220 "14 40 ‘II 220 "II 6o "04, 240 Ori73 60 ‘O7 240 15 80 ‘07 260 "09 re) "04, 260 18 Ico "10 280 *c6 100 ‘ol 280 ‘21 120 "12 300 04 120 mele) 300 <2, 140 "14 320 "02 140 *cO 320 "2.2 160 16 340 ole) 160 "02 340 “21 18 0716 360 9900 180 0°04 360 o18 TIDAL OBSERVATIONS. 393 Solar Elliptic Semidiurnal. (13) R. (14) T, h=0'035 cos {2(y—an)t— 12°"04h h=O'11I COS {2(y—gu)t— 38°96} (y—in)t Wh’ (y-int (y-anét (y-n)e OW a episue A 2) bie 5 me is a @ ft. © 180 0'07 g0 270 0°00 o 180 0°20 go 270 o'02 10 199 ‘o7 100 6280 0 86*co 10 I90 ‘22 Ioo 280 ‘OI Bo0200" | °67 IIO0 290 ‘oo 20 200 ‘22 110 290 ‘00 30 2t0 606 120 300 ‘Or go 210 ‘22 120 300 ‘Ol 40 220 ‘05 130 310 ‘o2 40 220n 7 20 130 310 603 50 230 *o4 140 320 ‘03 5o)) 230. “X6 140 320 ‘06 60 240 ‘o2 150 3309 "05 60 240 ‘53 150 339 ‘og JO 250 ‘or 160 340 ‘06 70 250 ‘og 160 340 ‘13 80 260 ‘ol 170 350 ‘06 80 260 *05 17O 350 “17 go 270 0'00 180 360 0°07 go 270° 0702 180 360 020 Lunisolar Quarter-diurnal (Helmholtz). (15) MS. h=o'017 08 {4(y—40—49)t—216"'79} (y—40—4)t h' (y—40—4n)¢ fo] ° ft. ° fe} ° go o'0o 180 270 10 100 "00 190 280 20 110 ‘00 200 290 30 120 ‘ol 210 300 40 130 "02 220 310 50 140 03 230 320 60 150 03 240 330 70 160 "02 250 340 80 170 ‘ol 260 350 go 180 000 270 360 SR —o0'290 ft.*=7'157 ft. Ap=7 149 ft. A,—ZR—o'290 ft.= —o'008 ft, —o'o1 ft. The following example will illustrate the manner of computation at pre- sent employed, in which the whole of the evaluated tide-components are taken into account, excepting those of long period, the values of which, for Kurrachee for successive years, have not agreed well together; they have, therefore, been omitted in the computation. Find the height of the tide at Kurrachee for every hour of the day for 1868, November 2, commencing at 0% astronomical reckoning. For 1868, - November 2, 0" Kurrachee mean time, Sidereal time = =221:86 Sun’s mean longitude = n=221-86, Moon’s mean longitude = o= 67-42, Moon’s mean anomaly = o—w=281-00, from which the whole of the arguments can be obtained. The values of the arguments for the succeeding hours are obtained from the arguments for noon by successive additions of their respective hourly in- * In the lunisolar declinational diurnal and semidiurnal tide the swn of R, and R, : less 0°29 ft, was applied. , 3894 REPORT—1872, crements (p. 361), and these additions may be continued for any period whatever. These are most readily obtained by the use of the arithmometer of Thomas (de Colmar). The residual differences, on this and the following page, are for the most part negative, and indicate that the mean height of the water on the day in question was above the mean height of the water for the whole year. On trial it will be found that the excess equals 0°15 of a foot, a quantity such that, if applied to the residual differences, will make them all very small. Kurrachee, 1868, November 2. —— Nea ep AT ied a OR See 5 ft. ft. ft. ft. ft ft. I y—7 o'00 1°67 1°30 83 *39 II 07 2) =o 15444 5:22 460 3°49 2°25 1'l5 38 Bo Ly. 221°8 1°29 87 “5 23 06 (ote) 4 \y—20 87°02 IS 'O7 "02 fefo) *O2 07 5 \y—2n 138°15 ore) ‘02 06 12 20 29 6 ‘y—210—70 2.94°94. "04. or co ol 03 038 7 —ictiw 13°94 "43 13 02 ol "15 41 8 y—so+aw—-n 219°50 ‘08 II 12 12 ‘II 09 9 y—-fo-aw+n = 89°37 24 32 38 39 36 28 io y—20+7 308°88 14 14 12 ‘09 06 03 ie Oa elaaor 142°86 14 16 16 16 “15 14 12 y—3o+7 166'02 03 O4 06 09 II 14 13> y—37 T1093 ore) ol 03 05 *06 7 14 y—sn 249°07 09 oy ol co 03 07 15 y—3o—3n 77°22 ‘Ol *00 *00 ‘OI 03 03 A,—=2R—o'z90 ft. ...... —‘ol = ‘ol — ‘Or — ‘oI — ‘Ol —-‘or Caleulated height = —=C=9'52 7°36 5°80 3°91 2°62 2°14 Height from diagram =O=9'7 79 58 40 2°7 2°3 C—O= — ‘18 — ‘04 co «360 — 09s — 08 — 16 No.of 6". a 8 oe 10", US 12h: 134, 14. Table. ft. ft. ft. ft. ft. ft. ft. ft. ft. I 27 67 1°16 1°62 1°93 2°00 1°82 1°43 "95 "Iq "62 1°66 2°91 4°06 4°94. 5°33 5°03 4°08 3 03 12 24 “38 53 67 84. 1°04, 1°28 4 15 "2.5 "38 “50 65 ‘78 “90 1'00 1°08 5 "39 "49 57 *65 ‘71 "74 ue "74 ‘71 6 “12 15 "16 15 BL. *o9 05 ‘ol *oo 7 *70 I'00 I'Ig 1-2 Ils "92 63 "33 "II 8 05 *O2 "00 ‘co Toy 03 ‘O7 "IO 12 9 "19 "10 *O2 ‘00 ‘02 "09 "19 28 36 10 ‘ol "00 ‘Or "04. "07 "10 “13 14 Fe] iI 12 IO "08 06 ‘OA 03 ‘Ol ‘oo ele) 12 *16 18 "20 ‘21 22) "22, 22 *2 "19 m3 ‘07 *05 *O4. "02 ‘Or "00 nolo) *o2 "03 14 one 18 122 oa, *20 15 "0g "04. ‘or 15 ‘ol ‘oo “00 ‘or "O02 "03 “O02 "oO “00 — SOF =" *O Pe eabeFOl) is “OT — "GT 4h sO) ey 8:0 98 10°3 Iro 10°4 gt C—O=— 17 — ‘28 — ‘08 oo )6©— 706 — ‘02 + ‘04 — "04 — ‘06 BRIGHTON WATERWORKS. 3895 No.of 15%, 16%, U7P: 18", 19%, 20%, 21h, 22h. 235, Table. ft. ft. ft. ft. ft. ft. ft. ft. ft. I *49 18 09 26 *62 108 1°52 1°80 1°86 2°31 1°55 *56 05 "25 Ils 2°42 3°66 4°65 3 1°54. 1°84. 211 249 2°45 2°45 Bz 2°03 1°67 4 112 1'l4 112 1'07 *98 88 75 62 47 5 65 57 “48 38 28 20 12 06 o2 6 ol 03 *O7 II "14 16 15 13 og Gi fefe) 05 "24. SI “SI 1'07 ey 1°22 109 8 12 II "09 *06 03 ‘Or (ele) ol 03 9 *39 38 °33 23 I4 06 oI ol 04. 10 12 08 06 "03 ‘Ol 00 or O4 07 II ol o2 03 05 ‘07 09 II 3 14 12 17 15 12 10 ‘O7 05 03 “OL (ole) 13 06 06 7 O7 *O5 04 02 or {ele} 14 (ole) 03 07 12 18 2Z 22 20 15 15 ol 02 03 02 *00 (oJ) OL ‘02 03 — ‘Ol — ‘ol — ‘Ol — ‘ol ~— ‘OI ~— ‘OL = ‘Or = ‘or — ‘or = 749 620 546 5°38 6°07 745 Sor 9°94 10°30 O= 97:7 64 56 55 64 76 Oe Io'k 10'S C—O=— ‘21 ~'20 — 14 —'12 = 33 — ‘15 ~— ‘19 — ‘16 — 20 On the Brighton Waterworks. By Epwarp Easton, C.E., F.G.S. [A communication ordered by the General Committee to be printed cn extenso.| Oxyviousty the first question an engineer asks when called upon to design works for the supply of water to a large population is, From what source can water of pure quality, and practically inexhaustible in quantity, be obtained ? On taking a survey of the country surrounding Brighton, its most striking feature, probably, is the entire absence of all streams, and, indeed, of all signs of the existence of the water the engineer is in search of. Standing on one of the highest Downs above the town, and looking down upon the slopes and valleys below him, the aspect of the country,as far as the eye can reach, appears for his purpose as unpromising as the Great Desert of Sahara. But just as in that vast arid region there exists beneath the burning sands the element which, by the application of scientific knowledge and mechanical skill, will change the useless desert into a fruitful plain, so lie concealed within the apparently dry material of the chalk stratum streams of excellent water which, though not presenting to the eye the beauty so admirably delineated by our great English painter, are none the less unfailingly “ flowing to the sea.” Let us imagine our observer overtaken by one of those sudden and violent storms of rain which were so frequent during the earlier part of this year. He is looking down into a basin naturally formed in the chalk of perhaps two square miles in extent. The middle or bottom of the basin is at least 60 feet below the lowest part of its sides. In an hour there falls sufficient rain to fill the lower and smaller area of the basin to the depth of several feet. No such result, however, follows the downpour ; the rain disappears as quickly as it falls, and in less than an hour the surface of the ground is as dry as it was before the storm. The water has all been received into the absorbing ground, and is finding its way through the pores of the chalk down into sub- terranean streams and so into the sea. That this is the case can be ascertained by walking down to the shore at low water, and tasting any of the numerous 396 REPORtT—1872. rills flowing from the higher parts of the beach through the shingle. But these streams are rills and not torrents, as they might be expected to be after the enormous downfall of rain ; and there is clearly some storage reser- voir interyening which has prevented its immediate discharge. This is the chalk itself, which acts as a sponge and stores up the water until saturation takes place, and it is obliged, as it were reluctantly, to give up what it has lost the power of retaining. The problem now to be solved by the engineer is, How can this water thus running wastefully into the sea be made use of for the purpose in view ? A description of the waterworks constructed for the supply of this place will go far to answer the question. Brighton has always been supplied with water from wells sunk in the chalk stratum. In a description of the town, written in the year 1761, by Dr. Relhan, a physician who succeeded the well-known Dr. Richard Russell, it is stated :—‘‘ The town is supplied from a variety of wells. The water most esteemed by the inhabitants is drawn from a well in North Street, and that preferred by the Company is obtained at the Castle Tavern. These waters answer every domestic purpose of life extremely well; and as the qualities of springs of any place have been from the time of Hippocrates to this day looked upon as a mark of those of the air, the sweetness and goodness of spring-water here may with propriety be esteemed a corroborating preof of the healthfulness of the air of this town.” Such wells as these supplied the inhabitants until about the year 1830, when a Company was formed by a few public-spirited men, the late Mr. Peter Cazalet and Dr. Taylor, who, I believe, is still living, being among its most active members, and a system of waterworks was established. A well was sunk near the Lewes Road, about 17 mile in a direct line from the sea- shore; and the water obtained was pumped by steam into a reservoir 220 feet above the sea, and thence distributed through pipes over the town. It was soon found that a single well would not give sufficient for the rapidly increasing population, and that the engines drew the water faster than the springs would give it; and tunnels or adits were driven in the form of a cross for the double purpose of obtaining more water and of making a storage from which the pumps might draw. A boring was also made into the chalk below to a great depth, but, for reasons which will be presently apparent, without any beneficial result. In the year 1852, in consequence of the great com- plaints of the scarcity of water, a new Company was formed, and an Act of Parliament obtained authorizing the construction of more extensive works. In the following year another Act was passed, by which the old Company sold their works to the new comers, and under the powers of which the works as they now exist were commenced. It was soon found that the wells and tunnels were totally inadequate for the supply even of the services then laid on, whose number was scarcely half that of the total number of houses; and the new Company, acting under the advice of the late Mr. Easton, their engineer, immediately on coming into possession of the works, commenced a new series of tunnels on a principle successfully adopted by Mr. Easton in the year 1834 when constructing works for the supply of the town of Ramsgate, a principle, as far as the writer is aware, which had never been before proposed. Ramsgate, as is well known, is built on the Chalk formation of the Isle of Thanet. Mr. Easton, in making his survey of the locality, observed that all along the sea-coast there issued at the base of the chalk cliffs numerous streams of fresh water running across the beach into the sea at low water; and he concluded that these streams came from cracks or fissures in the chalk, and that if tunnels were driven BRIGHTON WATERWORKS. 397 in a direction parallel to the sea, and at about the level of low water, these fissures would be cut across and the water intercepted and stored in the tun- nels. His conclusions were amply verified. Ramsgate has been supplied since the year 1836 from wells and tunnels made on this principle. The town of Brighton is very similarly situated. For at least 6 miles to the north, as many to the west, and nearly 8 miles to the eastward, there is a succession of Chalk Downs untraversed by any river or stream. ‘The geo- logical formation is that of the Upper Chalk with flints. Throughout the whole of this district (with a few exceptions of no importance) there is no system of agricultural drainage: none is required. The whole of the rain- fall, except that absorbed by the vegetation or given off by evaporation, per- colates at once into the chalk, and has its chief outlet in the sea as before described,—its chief outlet, because all round the base of the great escarp- ment at the northern boundary of the Chalk Downs there flow out springs more or less copious, which are formed by the overflow of the great chalk reservoir when saturation has taken place. Such springs, for instance, are those at Poynings, at Plumpton, and at Clayton. They find their way into the sea by the river Adur at Shoreham on the west, and the Ouse at New- haven on the east. The volume of these springs, however, is but a very small percentage of the total quantity of rainfall, the main body of which is absorbed by the chalk, and by its means travels to the sea. But although the chalk is as absorbent as a sponge, it is equally unready to give up its contents; and, consequently, were it not for some outlet more free and open than those afforded by its own pores it would necessarily overflow, and the ordinary phenomena of surface-streams would result. These freer outlets are provided in the shape of clefts or fissures extending almost from the surface downwards to a very great depth, which have been formed in all pro- bability, in the first instance, and continually kept open, by the action of the water through a vast series of years. Where the stratification of the chalk has not been disturbed by local upheavals and depressions, these fissures are almost invariably at right angles to the coast-line: each is entirely inde- pendent of its neighbour, and forms in itself a small rivulet, which takes its origin from the supersaturation of the chalk, and flows down collecting water as it goes, and finally discharges itself into the sea. The sides of these fissures are generally of the colour of mahogany, caused by the infiltration of small particles of the upper clays, and are polished by the continuous friction of the water. The fissures vary in size, but are seldom more than a few inches in width, and generally not more than 2 of an inch; there is there- fore considerable resistance to the passage of the water, and consequently as the body of the chalk gets full the pressure keeps on increasing, as shown by the varying level of the water in the wells. The diagram on the wall shows the quantity of rainfall of each month for the 10 years 1862 to 1872, and also the fluctuations of the level of the water in the -wells on the Lewes Road. This latter varies, as will be seen, from as low as 5 feet in depth in the autumn of the year 1864 to as much as 88 feet in depth in the spring of the year 1866. Speaking generally, the maximum quantity of water in the chalk is in March each year, and the minimum in October to December ; and the curve formed by the depths of the water follows that of the quantity of rain at an interval of four months, the highest part of the one curve being nearly coincident with the lowest of the other. It follows that the chalk is acting exactly as a storage reservoir, and is receiving the surplus rainfall of the months of October, November, December, and January (when, in con- sequence of the low temperature and the comparative sluggishness of vege- 398 REPORT—1872. tation, nearly all that falls goes down to feed the springs), and giving out in the summer the quantity so stored. At intervals the reservoir becomes full to overflowing, and then is seen the same phenomenon which is known in the Caterham valley as the rise of the Bourne, and the surplus water bursts out. » This happened in 1852 in the Preston valley, when there was a con- siderable stream running down the London Road, and in 1866 in the Lewes- Road valley, when the basements of the houses were flooded with the spring- water. A similar bourne or overflow occurs periodically after wet seasons and runs down through the town of Lewes. The course of the rainfall, in its passage to the sea, is still further illus- trated by four sections, which show the depth of water in a number of wells, soundings of which were all taken at the same time. Sections A, B, C give the soundings of wells situated in lines running northward from the sea, and as nearly as possible at right angles to the coast-line. Section D gives the depths of several wells dug at about the same distance from the sea, along a line running from E.to W. It will be seen that there is a uniform slope in the water-level of the chalk in the former sections, whilst the water- level in the latter is almost the same throughout. The furthest of the wells in sections A, B, C is not more than 2 miles from the sea; but levels taken to a well lately sunk at the foot of the chalk escarpment, about 1 mile east of the end of Clayton Tunnel, show that the water there stands at the height of about. 250 feet above low water, and that the line of the water in section B B would, if produced, very nearly cut that of the well just mentioned, which is about 6 miles in a direct line from the coast. Up to the year 1865 the whole of the town was supplied from the Lewes- Road Works; but in that year it was determined, in consequence of the great demand for water, to erect another pumping-station on the west side. Accordingly a well was sunk at Goldstone Bottom, and tunnels driven to the extent of about a quarter of a mile across the valley, parallel to the sea. Goldstone Bottom is a naturally formed basin in the chalk, the lowest side of which, nearest the sea, is more than 60 feet higher than the middle or bottom of the basin. The water is obtained, as at Lewes Road, from fissures running generally at right angles to the coast-line; but they are of much larger size and at far greater distances from each other: whereas at the Lewes- Road Works it is rare that 30 feet of tunnels were driven without finding a fissure, and the produce of the largest was not more than 100 to 150 gallons per minute, at Goldstone nearly 160 feet were traversed without any result, and then an enormous fissure was pierced, which delivered at once quite 1000 gallons per minute; and the same interval was found between this and the next fissure, which was of a capacity very nearly as great. In consequence of the great size of these there is a much freer vent to the sea, and the water stands relatively to the Lewes-Road valley at a much lower level, being gene- rally not more than 25 feet above low water. The fluctuations also of the water are not great, the difference of the quantity of water being felt rather by the impossibility of the pumps lowering its level than in its rising higher. The total length of the tunnels at Lewes-Road Works is 2400 feet, and at Goldstone 1300 feet. So much for the sources of the water. A short description of the pumping and distributing works must now be given. The district supplied by the waterworks comprises not only the parish of Brighton, but the neighbouring parishes of Hove and Preston. The number of houses supplied, which in 1854 did not much exceed 7000 when the new Company purchased the works, had risen on the Ist of August last, when BRIGHTON WATERWORKS. 399 they were transferred to the Corporation, to 18,000, The number of inhabi- tants at the last census in the whole district was 103,000, to which must be added, in the fashionable season, from 30,000 to 50,000 visitors. The area of the district is considerable, being, as nearly as possible, four miles in length from east to west, and about two miles from north to south. The ground is very undulating, varying in level from 30 feet above the sea to as much as 450 feet. In order to avoid lifting the water higher than is neces- sary and at the same time to prevent undue pressure on the service-pipes and fittings, the plan has been adopted of dividing the district into four zones or services, each fed by its own reservoir or reservoirs, with its own system of main pipes. The highest zone (at present but little built upon) is com- manded by a reservoir containing 500,000 gallons, built at a height of 450 feet above the sea, on the Down, about half a mile north of the Grand Stand of the racecourse. The next zone is called the high service. It is fed from two reservoirs— one at Park Road on the east, containing 500,000 gallons, and the other on the Dyke Road, on the west side, containing 600,000 gallons ; both of these are at the same level of 300 feet above the sea; they are connected by distri- buting mains, and give a supply to about two ninths of the town. The third zone is the middle service, supplying about three ninths of the whole number of inhabitants. It draws its supply from a reservoir near Brighton Park, containing 2,000,000 gallons, the water-level being 220 feet above the sea. The remaining or low service supplies about four ninths of the whole, and is fed from two reservoirs—one above the Lewes-Road Works containing 1,000,000 gallons, and the other at Goldstone Bottom 600,000 gallons. These are at the level of 150 feet above the sea. The high and low services, as already mentioned, haye reservoirs at the same level on both sides of the town, with main pipes connecting them together. Those on the west side were constructed in 1863 and 1865, when the western districts increased, and it was found difficult, in consequence of the great length of the supply main, to give proper pressure at the extremi- ties of the districts. The effect of putting them at the same level is that during the night, when little water is drawn by the consumers, the water pumped into the reservoirs on the one side passes through the mains to those on the other, and becomes available in the morning for serving the houses, the supply being drawn at an equal pressure from both reservoirs simultaneously, the length of the supply mains being thus practically reduced by one half. All the zones are connected together, and stopcocks are arranged so that, in case of fire, the water from the upper can be let down into the lower service mains, self-acting valves being fixed on the outlet of each reservoir to prevent the passage into it of the water from the reservoir above. The total quantity of water pumped daily varies from 23 millions in the winter to 3 millions in the summer months. The amount per head per diem is from 17 to 20 gallons, including street watering and large consumers. The water is supplied both on the intermittent and constant system. When the new Company obtained their first Act, the intention was to furnish a supply only on the constant service ; but on buying the old works they found themselves unable to keep up the supply in consequence of the enormous waste of water caused by the old fittings in the houses; and as they could not obtain any relief in the shape of delay, but were obliged at once to give constant service, the Directors determined to lay a duplicate set of service- pipes in every street, so that when called upon they could give either form 4.00 REPORT—1872. of supply to every house. This was done, and Brighton is now in the position of being able to give constant service to one house, and intermittent to the house next door in the same street. The number of constant-service customers now amounts to about 5000. The pumping-power at the two stations of Lewes Road and Goldstone Bottom is as follows :— At Lewes Road there are two engines of the nominal power of 100 horses and 150 horses respectively, the one capable of raising out of the wells 130,000 gallons per hour, and the other 150,000 gallons per hour: the boiler-power at this station is equal to about 350 horses. At Goldstone Bottom there is one engine of the nominal power of 150 horses, raising 150,000 gallons per hour, and supplied with steam from three boilers of the collective power of 240 horses nominal. The wells and tunnels at each station are capable of affording at the dryest season the maximum daily supply of 3 millions of gallons. The engines are all on Woolf's principle, high and low pressure condensing beam-engines, the smaller cylinder being 28 inches diameter, and the larger A6 inches, the stroke of the latter being 8 feet. They are erected directly over the wells, which are of an elliptical shape, 12 feet across the longer and 8 feet across the shorter axis. The centre of the beam is immediately over the centre of the well. On each side of the centre, at the bottom of the wells, is fixed a single-acting pump 293 inches diameter, 3-feet stroke: these pumps raise the water into the low-service reservoirs above described. Also under the beam, at the crank end, is fixed a bucket and plunger double-acting pump, drawing its water from the delivery of the deep-well pumps, and forcing it to the high or middle service at pleasure: this pump is 2 feet diameter, 4-feet stroke. At the Lewes-Road Works there are also two sets of three throw-pumps capable of raising 400 gallons per minute each, and at Goldstone a horizontal double-acting pump, equal to 600 gallons per minute, for the middle service. The highest service of all is fed only from the Lewes-Road Works, there being a separate double-acting pump under each engine at that station exclusively for its supply. Thus each of the engines at the same time can pump into all the three zones or services, and keep up the supply without any manipulation of cocks and valves, and without altering the working pressure on the engine. The reservoirs are all constructed in the chalk of brickwork, without any puddle ; they are lined with two courses of tiles in pure cement, and are arched over with 44 arches in cement, and covered 12 inches to 18 inches deep with soil. This arrangement keeps the water perfectly pure and cool, and prevents the vegetation which grows so quickly in chalk water when exposed to the action of light and air. From the time of its leaving the tunnels at the bottom of the wells to its being delivered into the houses it is never exposed to any contaminating influence, and is thus used by the inhabitants, especially those on the constant service, in a perfectly pure state, It will be seen from the foregoing that— 1. There are two distinct sources of supply, each sufficient at the dryest season to give the maximum quantity required, and capable of still further development as the town increases. 2. There are three sets of pumping-apparatus, each equal, on an emer- gency, to the delivery of this maximum quantity in 24 hours. 3. There is besides a reservoir storage of two days’ supply, on the average, for each zone or service. See ON AMSLER’S PLANIMETER. 401 On Amsler’s Planimeter. By ¥. J. Bramwe11, C.E. [A communication ordered by the General Committee to be printed in extenso.] Tuts machine for measuring the area of any figure, however irregular, by the mere passage of a tracer round about its perimeter, has now been in use for some years; but, so far as the writer is aware, no easily intelligible statement of its principles of action has ever been made public. Although no doubt the mere construction of the planimeter is now generally known, it may enable the explanation which is about to be offered to be more easily followed if a sketch of the actual machine, as at work upon a map, be given here (see fig. 1). Fig. 1. Assume the planimeter to be anchored by its point X, and the tracer T to be at some place, say A, on the circumference of the area to be ascertained ; and assume the indices on the first wheel R and on the second wheel S to be at zero, and that then the tracer T be carried along the perimeter of the area in the direction of the arrows (with the sun), the indices will give a reading up to four figures, which will represent square inches, to two places of whole numbers and to two places of decimals. This movement of the indices is effected by the wheel R, the edge of which bears upon the paper, so that as the tracer T is made to go round about the figure to be measured, the wheel R, from its contact with the paper, receives rotary motion, and by means of the worm-pinion L and worm-wheel u, communicates a diminished motion (1-10th) to the horizontal wheel s. 1872. 25 402 REPORT—1872., The circumference of the wheel RB is “ divided,” and it works against a vernier at y; the horizontal wheel s gives ‘‘ tens” in square inches, the larger divisions on the travelling wheel R “units,” the smaller divisions on that wheel “tenths,” and the vernier “ hundredths” of square inches. All that has to be done for ascertaining an area is to read the indices after the machine is anchored and the tracer is put to the starting-point; but before it is started, to book the reading, to re-read after the circuit of the figure has been made, and then to deduct the first reading from the second; the remainder gives the area (in square inches and decimals) of the particular figure. The foregoing being, briefly stated, the construction, the manner of using, and the result of that using of the planimeter, it now remains to endeavour to show, as intelligibly as possible, why it is that such an implement, by merely following the boundary of a figure, should give with absolute accuracy the area of that figure. Such a proposition at first sight appears to involve an impossibility. One is in the habit of saying, and of most truly saying, that there is no fixed relation between perimeter and area; and of saying, moreover (and also truly), that not only is this the fact when areas of great irregularity are dealt with, but, as regards direct proportion, it is also the fact when the most regular figures (figures in all respects the same, except in their actual size) are under consideration ; for it is as true that the circumferences of perfectly regular figures like circles bear no more fixed direct proportion to the areas of those circles, unless the exact size be known, as it is true that the coast-line of Norway, indented with its deep fjords, bears no more relation to the area of that romantic country than the perimeter of a prosaic rectangular portion of the United States bears to the square miles of prairie contained within it. These things being so, it does, as has already been said, seem at first sight absurd to endeayour to obtain from the traverse of a perimeter, be that perimeter the most regular imaginable (and if possible still more absurd when that perimeter may be the most irregular imaginable), the correct area con- tained within it, not merely in terms of the perimeter, but in a definite stan- dard measurement, such as square inches. As a preliminary to the investigation of the action of an elementary plani- meter, let the results of the moving of a plain cylinder in contact with a flat surface, and under certain varying conditions, be considered. Assume a cylinder, as A in fig. 2, and that it is intended to move that cylinder parallel with itself in the direction shown by the arrow, over the length « y. The cylinder may be (1st) at right angles to the direction in which it is to be traversed, as in A A‘. If under these circumstances the cylinder be moved from w to y and brought into the position as dotted at A’, the motion will be entirely one of rolling, without any sliding whatever; and if there were upon the surface a trace (a y) of ink capable of making a mark upon the cylinder, there would be found circumferentially upon it, when it had reached the new position, a line, the length of which would be equal to wy. (2nd) The cylinder may be placed with its axis parallel to the direction of motion, as at A A°; then no rolling action would take place, but the cylinder would simply slide endways upon the surface. The cylinder would, however, still bear upon it the trace a y, equal in length to the distance it had moved through, but that trace would be obviously a mere straight line in the direction of the axis of the cylinder. (8rd) The cylinder may be in a position inter- mediate between that of A A' and A A*; that is to say, may be neither at right angles to the line of motion, as in A A’, nor parallel with the line of motion, as in A A*, but at an angle therewith, as in A A*. In this instance, € ON AMSLER’S PLANIMETER. 403 on the cylinder being caused to traverse from # to y, the motion will be one compounded of rolling and of sliding; the trace will still be made on the cylinder ; the length of that trace will be, as before, the length « y, but the trace will now be a spiral, which may be developed into the triangle w y z, and the base wz will bear such a relation to the hypotenuse wy as the base mn of the triangle mno bears to the hypotenuse no. But it has been ' =a 2 oe ee eee ey a N said that in the journey from to y the cylinder will have had a motion compounded of sliding and of rolling; the extent of the rolling will clearly bear that proportion to the total traverse x y that the base m bears to the hypotenuse no; and this proportion may obviously be any thing between the 252 404, REPORT—1872. absolute equality which would exist in A A’ down to the absence of all rolling motion which would obtain in the case of A A’. These preliminaries being stated, let it be inquired how they apply to the action of the planimeter. For this purpose it will be well to refer to the sketch, fig. 3. This sketch shows an imaginary elementary planimeter, used Fig. 3. 0 A. A + | ' { i { B* a oo ee en on ee of rn ee ee ee fe ¢ Dp’ Co D (ie eS ee (helps eee ee lb to ascertain the area of the rectangle A BC D, the length of each of its sides AB, CD being 5 inches, and the length of each of its ends D A, CB being 2 inches, so that its area is 10 inches. Let M be a block carrying the pivot N and capable of sliding in the straight groove O O in the bridge P, pinned down over the paper, and let Q be a rod pivoted at N, and say, for the sake of illustration, 5 inches long from the pivot N to the tracer T at its opposite end; and let it have on it, say at R, a wheel R, having a circumference of exactly 2 inches; and also, for the sake of a second illustration, let there be similar wheels as R’, R” free to revolve on the rod Q, at distances greater than the distance of the wheel R from the pivot N; and let there be to one of the wheels, say R, a pointer 8, to enable the graduated divisions on the circumference of R to be read off. ee ON AMSLER’S PLANIMETER. 405 Now let it be assumed that the tracer T is moved from C to D; the result will be that during the motion the block M will gradually pass along the groove O until the time when the tracer T has reached D; and then, as the length of the rod Q is exactly 5 inches, equal to the length of the side C D (5 inches), the block M must have passed along the groove O until the centre Nin that block is immediately over the point C, and the centre line of Q is coincident with the line CD. If, now, the tracer T be moved along the 2 inches from D to A, the block M must move parallel with it, and the axis Q of the wheels R, R’, R” will therefore be at right angles to the line of motion, and the wheels themselves will, like the cylinder A in A A!’ of fig. 2, have a rolling motion, and a rolling motion only ; and thus by the time the tracer T has reached the point A, these wheels will each have made an entire revolu- tion. If, now, the circumference of R or R’, R” has been divided into ten equal parts, and if on setting out from D pains had been taken to put the wheel R with its zero mark to the pointer S, it would be found, on the arrival of the wheel at A, that it had made an entire revolution, and that therefore the index would read 10, equal 10 square inches—viz. the multiplication of the length of the radius Q (5 inches) into the circumference of the wheel R (2 inches). : Now let it be assumed that the implement is to be used for the purpose of measuring another rectangle A BC D, also of 10 inches area, having its sides and ends respectively 2 inches and 5 inches long; so that in this instance (see fig. 4) the ends have the 5-inch measurement in lieu of the 2, and the sides have the 2-inch in lieu of the 5. Once more let the tracer T be moved from C to D; the block M will now have only passed along the groove O a comparatively insignificant distance towards C, and the rod Q will lie at the angle shown, so that it will form the hypotenuse (5 inches long) of a triangle of which the base will be C D (2 inches long). If, now, the tracer T be moved from D to A (5 inches), the block M will make a similar motion in the groove 0; and when the tracer T has reached A, the rod Q will have moved parallel to itself, and will be found in the position shown in fig. 5. But, as has already been said when speaking of A A® of fig. 2, if a cylinder capable of rotating be caused to move over and in contact with a surface when it is in a position neither parallel with, nor at right angles to, the line of motion, and if it be made to preserve its own parallelism, the result will be a motion compounded of sliding and of rolling, and the amount of the rolling will bear such a relation to the whole motion as the base mn bears to the hypotenuse x0. In the instance, therefore, under consideration the ratio of revolution to the whole motion will be that of 2 to 5; therefore if the zero on the wheel R were brought to the pointer S at the time of setting out from D, it would be found, when the tracer had arrived at the end A of its 5-inch journey D A, that the wheel R would have made just one revolu- tion, and that the figure 10, indicating 10 square inches, would present itself. From a consideration of the foregoing two cases, it will be seen that the « rate” of rotation of the wheel R, when it moves along the line D A, depends upon the length of the line CD, and the “quantity” of such rotation upon that of the line DA. These two expressions, “rate” and “ quantity,” will be used hereafter in the above senses. As an illustration of “rate” and “ quantity,” suppose that the rectangle of fig. 3 had only been half as long as the one that has been considered, namely 22 inches, and had been bounded by the line D’ A’; if, then, the tracer had been moved from D’ to A’, the “rate” of revolution of the wheels R é&e. would have been one half of the total distance moved through by the tracer, 406 REPORT—1872. because C D’ (equal 2} inches) is one half of the length of the rod Q. The “quantity” of motion in going along D’ to A’ would, however, have been the same as it was in passing from D to A, because D’ A’ equals DA; but an Fig. 4. Fig. 5. equal “ quantity ” into half the “rate” will only give half the total amount, and therefore the wheels R would have recorded a half revolution, equal 5 square inches, thus accurately giving the area C D', A1B. On the other hand, ON AMSLER’S PLANIMETER. 407 assume that the height of the rectangle had been halved, and that it had been bounded by the lines C D, D' B’, then the wheels R &c. in traversing from D to D" would do so at their full “rate” of revolution, the line C D being 5 inches long ; but the “ quantity ’’ of such revolution would only be half that which it was in going from D to A, because DD” is only half DA, and therefore the wheels again would register but a half revolution, indicating truly the 5-inch area of the 5-inch by 1-inch parallelogram D D”, B'C. In each of the foregoing cases it has been assumed that the index is read when the apparatus is about to start from D, and is re-read when it reaches A. Such a reading would be quite sufficient in the case of a rectangle where the groove OO is assumed to be in the prolongation of one of the sides (BC) ; but under any other circumstances the complete circuit of the figure must be made. To test this, let it be assumed that the tracer T starts from C, and that the index on R is read just before the starting, and then let it be examined when the tracer T has reached D; it will be found that the wheel R has received an amount of rotation approximately that due to its traversing the arc of the radius N R, that R’ has received a larger amount of traverse, and R” a still larger amount, owing to their greater distance from the centre N ; but it will be afterwards found that these amounts of revolution may be wholly neglected, and that they will not come into the final computation, because, assume the tracer T to have attained to the point A and to have put into the wheels R, R’, R" the one revolution which it has been seen that traverse would give, those wheels would be found at A (were there any means by multi- plying gear, as in the actual machine, to record more than the one revolution) to have made the one revolution each, plus the varying amounts of revolution which they would have received in their journey from C to D. But in their back journey from A to B it is manifest they will each of them unwind (if such a phrase may be used) exactly the quantity of revolution which was put into them in moving from C to D. Further, during the passage from B to C to complete the circuit, the direction of motion being parallel with the position of the rod Q, the axle of the wheels R, R’, R", no rolling movement will be communicated to them, as they will be in the condition of the cylinder A A? of fig. 2, and will merely slide over the paper, so that on the arrival of the tracer T at C, having made the circuit of the rectangle, there will be found in them the one revolution, and neither more nor less than the one reyolution, generated by the traverse from D to A. The next point to be proved is the manner in which the implement will truly record if the groove O O be not on the line produced by prolonging one side of the rectangle. Let fig. 6 represent a rectangle, say 2 inches long on its side C D and 5 inches high at its end DA, and containing therefore 10 square inches, and let X Y be a line parallel with BC, and as far removed (2 inches) on the right hand from it as D A is removed from it on the left hand, and let the groove OO be on the line X Y; then, if the tracer T were to stand at C, and the wheels R &c. were at zero, and if the tracer were then moyed along the line C B, there would be put an amount of revolution into R which would be compounded of the “ rate” due to the length YC and of the “quantity” belonging to the length CB, or 2 multiplied by 5 equal 10 inches, equal one revolution of R. But if now the tracer T be brought back again along the line BC, the wheel R will unwind the revolu- tion that was put into it, and on its return to C will be found at zero. Having thus premised that during the passage of the tracer T from B to C the wheel R will have unwound or made a negative quantity expressive of the rectangle B X Y C, let the measurement of ABCD be considered. As- 408 REPORT—1872. sume the tracer to start from C, and the wheels R &c. to be at zero, then in the passage from C to D varying revolutions would be put into these wheels corresponding approximately with the length of their arcs about the centre N ; Fig. 6. wollee B cc ia LAR Weenie | 4 wk. Hest oh 3 ML dy Be oie 2A mee OS) 2 SEA a eee then, on the arrival of the tracer at D, the ratio for the “rate” of trace between D and A will be established, viz. the proportion which Y D (4 inches) bears to the 5-inch length of Q, equal four fifths of the motion which the tracer T is about to make along DA; but the distance D A is 5 inches, and therefore ON AMSLER’S PLANIMETER. 409 the wheels R &c. will make a further 4 inches of circumferential movement, equal 2 revolutions, indicating 20 square inches. If, now, the tracer T be moved from A to B, there will clearly be unwound from all the wheels R &c. the amount of motion that was put into them in traversing from C to D, and thus the wheels R &c. will all be left with the double revolution indicative of 20 square inches. The only side remaining to be passed over is that from B to C; and if this traverse were devoid of effect on the wheels R &c., as the traverse from B to C was in the cases of figures 3, 4, and 5, then the imple- ment on arriving at C, at the end of the circuit, would record double the proper area, or 20 inches instead of 10; but in the outset of this paragraph it was shown that the journey from B to C in fig. 6 would unwind exactly one revolution of the wheel R, leaving therefore one revolution remaining, indicating, as it should do, 10 square inches for the area of A BC D. The next step is to show the ability of the implement to give the area correctly of figures which are not rectangular. Assume, as in figure 7, it be Fig. 8. required to find the area of the triangle BC D, and let it be imagined that in lieu of the straight line for the hypotenuse B D the boundary of the figure on that side were made by a number of extremely small steps,-as sketched ; if then the tracer T be made once more to traverse from € to D, the wheel R will have a certain amount of revolution given to it; and if it then be made to rise through the space D 1, it will have a “ rate” of revolution equal to the length of the line C D, and a “ quantity ” equal to the height D1; if it then 410 REPORT—1872. pass along the horizontal line 1 2, it will unwind that proportion of the revolution, put in on going from C to D, that is represented by the length of the line 1-2. If, now, it be made to rise from 2 to 3, it will have a “ rate” of revolution equal to the length of the line C D—1 2, and a “quantity” equal to the height of the line 23. If it now be carried along the horizontal line 3 4, another portion of the revolution given by CD will be taken out; and then if it be made to rise from 4 to 5, a further portion of a revolution will be put in, having for its “ rate”’ the length of the line C D—D 4, and for its “ quantity ”’ the height of the line 45. This may be followed through all the steps into which the hypotenuse has been broken up, and then it will be found, as is obvious, that the sum of all the horizontal lines 1 2, 3 4, 5 6, &c. is equal to the length CD, and that the traversing of them will therefore have unwound all the revolution that the passage along CD had put into the wheel R; but it will also be found that the sum of all the vertical lines 23, 45, 6 7, &e. is equal to D A; and therefore the “ quantity ” of revolu- tion given to the wheel R will be equal to that which it would have had, had it passed up the line D A, while the means of the lengths of C D—1 2, C D— D 4, C D—D 6, &e. will exactly equal the half of C D, and thus the condition of the wheel R in relation to the index § will, when it arrives by the zigzag path at B, be precisely the same as it would have been if it had gone by the way of the rectangle CC! CB, CC’ being half of CD. A large number of very small steps have been taken in lieu of the straight line hypotenuse D B. Obviously a greater number of much smaller steps, or an infinite number of infinitely little steps, may be substituted, until the traverse ceases to be made along steps at all, and becomes one along the slope line D B, in which condition of things the wheel R at any part of the traverse of the tracer along the hypotenuse is making a revolution compounded of the “rate” due to its horizontal distance from C, and of a “ quantity ” equal to the rise from D. The “ quantity” re- mains constant during the whole journey, but the “rate” regularly diminishes, and the mean of all the “rates” is that due to the proportion that half the length of the line C D bears to N T, the length of Q. Now if it has been proved that this elementary planimeter, no matter where anchored, can act efficiently in ascertaining the area of rectangles and of triangles, it is self-evident that it could truly ascertain the area of any other figure, because there is no figure from that of the regular circle to that of the most irregular boundary which cannot be represented by an indefinite number of straight lines lying at various angles—that is to say,a circle is only a polygon of an infinite number of sides, all equal; and any irregular figure may be divided into an indefinite number of sides, most probably unequal. It may now be said that the elementary planimeter has been shown to have its pivot N attached to the guide-block M working up and down in the straight groove O, that that groove has been sketched with its axis either in the pro- longation of BC or in a position parallel to BC, whereas in the actual planimeter there is no such straight groove at all; but the pivot N is at the end of a radius rod, which in its movement causes N to pass through the are of a circle, and that that are may have its chord in almost any position in relation to the line B C, and thus there are disturbing causes in the planimeter as manufactured which do not exist in the elementary planimeter. The answer to this objection, which at first sight appears so well-grounded a one, is that these differences between the real and the elementary planimeter may be left out of consideration altogether, as they really have no effect whatever upon the action of the implement. This can be made clear in a very few words. ON AMSLER’S PLANIMETER. 411 Assume, as in fig. 8, that the groove OO were placed at an angle to the prolongation of the line BC. If, now, the tracer T be carried along the straight line from C to B, the block M will haye moved along the groove O to M, and the wheel R will be found at R’; this will have communicated an amount of revolution to the wheel R due to its change of position to R; the other two wheels (R’, R”) will also have made movements depending princi- pally on their distance from N. Such revolution of R will be given without reference to any area to be measured by the traverse of the tracer T, for that has merely passed along the straight line CB. But on bringing the tracer T back to C, the block M and wheels R, R’, R” will be restored to the positions they held at the outset, and in being so restored the whole amount of revolu- tion put into the wheels R &e. will be unwound. But assume that the tracer T, instead of being carried along the line C B and back again, had been taken along the sides of the square C D A B back to C, the pivot N would return to identically the place that it had before the circuit was commenced; and whether during that circuit N moved in the groove OO as placed parallel to the prolongation of C D in fig. 3, or in it as inclined and as shown by full lines in fig. 8, or inclined and curved as dotted in that figure, could make no difference in the final result, because whatever amount of revolution might be given to the wheels R &c. by the movement of N along the path of the groove O (be that groove straight or curved, inclined or not inclined) would be taken out of them again on the return journey along that same path. Three wheels (R, R’, R'’) have been shown loose on the axle Q of the ele- mentary planimeter ; this, as was said, has been done for the mere purpose of illustration, to show that wherever situated they will register just the same. In the actual machine as manufactured and sold, the position of the wheel is about that which has been given to R, and in this position it serves to support the hinge-joint, and is sufficiently far from the tracer T to get rid of the danger of lifting the wheel from the paper if the tracer T were held a little too high. It is hoped it has been made clear that one revolution of the wheel R will always express an area equal to the circumference of that wheel multiplied into the length of the rod Q, the radius N T *. If these elements are constant, the scale of the planimeter reading is con- stant ; but if these be capable of variation, then the scale can be varied. Ad- vantage is taken of this property in the construction of one form of the imple- ment in which the length N T is made adjustable, and thus the instrument may be readily arranged to read either French or English superficial measure. The purposes for which the planimeter may be applied are very numerous. It gives to the Surveyor the readiest means of calculating the acreage of whole estates or of separate fields. To the Hydraulic Engineer it affords a mode for ascertaining with ease and certainty the drainage area of a country, or the area of the sections of rivers, an important thing when it is desired to obtain the dimensions of numerous sections of a stream to ascertain its hydraulic mean depth. To the Naval Architect it presents itself as an aid in calculating the areas of the successive sections of a vessel, and thus most materially assists him in readily determining not merely the total displace- ment of a vessel, but those more complex problems which he has to solve. * The implement as manufactured and sold has a length of radius of about 44”, and a cir- cumference for the wheel R of about 2,8”, giving 10 as the multiplication. It has been stated in the outset that one complete revolution of this wheel records an area of 10 square inches. 412 REPORT—1872. To the Mechanical Engineer it is a great boon, as by its use he is enabled rapidly and with accuracy to find the average pressure upon the piston of a steam-engine as given by indicator diagram: all that is necessary is to ascertain the area of the figure, then to divide that area by the length and the mean height; the representative of the average pressure is at once obtained. There are, no doubt, other instances in which such an implement is of great use, but the writer feels it is unnecessary to adduce them in support of the claim of the planimeter to the consideration of engineers and of men of cognate professions ; and he brings his paper to a conclusion with the expres- sion of a hope that he has by the use of plain, in fact homely, description solved the problem which he set himself in the outset, and has made it clear how it is that the area of any figure, however irregular, can be recorded in definite standard units of measurement by the mere passage of a tracer along the perimeter of that figure. NOTICES AND ABSTRACTS OF MISCELLANEOUS COMMUNICATIONS TO THE SECTIONS. MATHEMATICS AND PHYSICS. Address by Warren Der La Ror, Esq., D.C.L., Ph.D., F.RS., V.P.OS., V.P.RAS., President of the Section. My predecessors in this Chair have addressed you on many subjects of high interest in Mathematical and Physical Science: I do not contemplate passing in review the recent discoveries in Astronomy or Physical Science, but intend to confine myself, in the main, to Astronomical Photography ; and in selecting this branch of science as the subject of this introductory discourse, 1 think that I shall have your approval, not only because I have given special attention to that subject, but also because it is about to be applied to the determination of a fundamental element of our system, the solar parallax, by observations of the transit of Venus in 1874, and probably also in 1882. Nothing is so lastingly injurious to the progress of science as false data; for they endure often through many centuries. False views, even if supported by some amount of evidence, do comparatively little harm; for every one takes a salutary interest in proving their falseness; and when this is done the path to error is closed, and the road to truth is opened at the same moment. Tt will be conceded that Photography, when applied to scientific observation, un- doubtedly preserves facts. But the question has sometimes been raised, are photo- eet records absolutely trustworthy representations of the phenomena recorded ? f not, what is the extent of truth, and where are the inlets for errors and mistakes ? Not only has photographic observation gained a wide range of applications in astro- nomy, but in every other branch of physical science its help is daily more and more taken advantage of ; and although, in speaking of this art, I shall confine myself to astronomy, the observations which 1 propose to make may be suggestive with reference to other branches of physics. As an instance of the application of this art to optical physics I may in this place call attention to the very successful delineation of the solar spectrum by Mr. Lewis M. Rutherfurd, of the United States. In Mr. Rutherfurd’s spectrum, obtained by the camera, many portions and lines are shown (in the ultra-violet for instance) which, while imperceptible to the retina of the, eye, impress themselves on the sensitive film. As a fact, lines which are single in Angstrém’s and Kirchhoft’s maps, have been recorded by photography as well-marked double lines, I will now review the application of the art to astronomy. Stellar photography was for some time applied at Harvard-College Observatory, U.S., to double stars, for the purpose of determining by micrometric measurement their relative angle of position and distance. The zero of the angle of position was found by moving the telescope in right ascension after an impression had been taken, and taking a second one on the same plate; this process gave two sets of photographic images on the same plate; and the right line passing through the 1872. 1 2 REPORT—1872. series gave the direction of the daily motion of the heavens. The probable error of a single measurement of the photographic distance of the images was found to be +0'"12, or somewhat smaller than that of a direct measurement with the common filar micrometer. The late Professor Bond, who applied photography to stellar astronomy, confining himself to stars brighter than the seventh magni- tude, discussed the results in various numbers of the ‘ Astronomische Nachrichten.’ No astronomer more unbiased could have been selected to decide on the comparative value of the photographic and direct observational method. His discussion shows that the probable error of the centre of an image was +0":051, and that of the distance of two such centres was +0"072. Adopting the estimate of Struve, --0'"217, as the probable error of a single measurement of a double star of this class with a filar micrometer, Professor Bond shows that the measurement of the photographic images would have a relative value three timesas great. He derived the further important conclusion, that deficiency of light can be more than compensated for by propor- tionate increase in the time of exposure. A star of the ninth magnitude would give a photographic image, after an exposure of ten minutes, with the Cambridge equatorial. In the reproduction of stars by photography, recently undertaken by Mr. Ruther- furd, the objects to be secured being so minute, special precautions were found to be necessary in depicting them upon the sensitive film, so that their impressions might be distinguishable from accidental specks in the collodion plate. To prevent any such chance of mistake, Mr. Rutherfurd secures a double image of each luminary, the motion of the telescope being stopped for a short time (half a minute) between a first and second exposure of the plate; so that each star is represented by two close specks, so to speak, upon the negative, and is clearly to be distinguished by this contrivance from any accidental speck in the film. A map of the heavens is thus secured, very clear though delicate in its nature, but yet one upon which implicit reliance can be placed for the purposes of measurement. Professor Peirce aptly says, “This addition to astronomical research is unsurpassed by any step of the kind that has ever been taken. The photographs afford just as good an opportunity for new and original investigation of the relative position of near stars as could be derived from the stars themselves as seen through the most powerful telescopes. They are indisputable facts, unbiased by personal defects of observation, and which convey to all future times the actual places of the stars when the photographs were taken.” « Mr. Asaph Hall, who shared with Professor Bond the work of measuring the photographic images and of reducing the measurements, has yery re- cently subjected the photographic method to a critical comparison, with a view to deciding on its value when applied to the observation of the transit of Venus. He appears, as regards its application to stellar observations, to underestimate the photographic method in consequence of want of rapidity ; but he admits that in the case of a solar eclipse, or of the transit of a planet over the sun’s disk, it has very great advantages, especially over eye-observations of contacts, inner and outer, of the planet and the sun’s limb, and that the errors to which it is subject are worthy of the most thorough inyestigation. The observation of a contact 1s uncertain on account of irradiation, and is also only momentary; so that, if missed from any cause, the record of the event is irretrievably lost at a particular station, and long and costly preparations rendered futile. On the other hand, when the sky is clear, a photographic image can be obtained in an instant and repeated through- out the progress of the transit; and even if all the contacts be lost, equally valuable results will be secured if the data collected on the photographic plates can be cor- rectly reduced, as will be proved hereafter to be undoubtedly possible. That the transit of Venus will be recorded by photography may now be announced as certain, as preparations are energetically progressing in England, France, Russia, and Ame- ricafor obtaining photographic records. There is also a probability of Portugal taking par in these observations ; for it is contemplated by Senor Capello to transport the isbon photoheliograph to Macao. There are at present five photoheliographs in process of construction for the observing parties to be sent out by the British Government, under the direction of the Astronomer Royal, Sir George B. Airy. The Russian Goyernment will supply their own parties with three similar instru- | TRANSACTIONS OF THE SECTIONS. 3 ments; and I am also having constructed one of my own for this purpose and for future solar observations. Ali these instruments, made precisely alike, will embody the results of our experience gained during the last ten years in photoheliography at the Kew Observatory whilst belonging to this Association. Oneonly of them,namely the photoheliograph which has been at work for some years at Wilna, is of a some- what older pattern; but how great an advance even this instrument is on the ori- ginal at Kew is proved by the delightful definition of the most delicate markings of the sun in the pictures which have reached this country from Wilna. Hitherto sun-pictures have been taken on wet collodion; but a question has been raised whether it would not be better to use dry plates. On this point M. Struve informs us that in two places (at Wilna, under the direction of Colonel Smysloff, and at Bothkamp, in Holstein, under Dr. Vogel) they have perfectly succeeded in taking instantaneous photographs of the sun with dry plates. As far, however, as my own experience has gone, r still believe that the wet collodion is preferable to the dry for such observations. Now, with reference to contact observations, which it must be remembered are by no means indispensable as far as photography is concerned, it may be conceded that there will attach to the record of the internal contact a certain amount of uncertainty, although not so great as that which affects optical observation. The photograph which first shows contact may possibly not be that taken when the thread of light between Venus and the sun’s disk is first completed, but the first taken after it has become thick enough to be shown on the plate; and this thickness is somewhat dependent on incidental cireumstances—for example, a haziness of the sky, which, although almost imperceptible, yet diminishes the actinic brilliancy of the sun, and might render the photographic image of the small extent of the limb which,is concerned in the phenomenon too faint for future mea- surements. On the other hand, having a series of photographs of the sun with Venus on the disk, we can, with a suitable micrometer (such as | contrived for measuring the eclipse-pictures of 1860, and which since then has been in continuous use in measuring the Kew solar photograms*), fix the position of the centre of each body with great precision. But the reduction of the measured distances of the centre to their values in arc is not without difficulty. Irradiation may possibly enlarge the diameter of the sun in photographic pictures, and it may diminish the size of the disk of a planet crossing the sun, as is the case with eye-observations; but if the images depicted are nearly of the same size at all stations whose results are to be included in any set of discussions, then the ratio of the diameters of Venus and the sun will be the same in all the plates, and it will be safe to assume that they are equally affected by irradiation. The advantage which, therefore, will result by employing no less than eight instruments precisely alike, as are those now being made by Mr. Dallmeyer on the improved Kew model, is quite obvious. If other forms of instruments, such as will hereafter be alluded to, be used, it will be es- sential that a sufficient number of. them be employed in selected localities to give _also connected sets for discussion. To give some idea of the relative apparent magnitudes of the sun and Venus, I may mention that at the epoch of the transit of 1874 the solar disk would, in the Kew photoheliograph, have a semidiameter of 1965-8 thousandths of an inch, or nearly two inches; Venus a semidiameter of 63°33 of these units; and the parallax of Venus referred to the sun would be represented by 47°85 such units, the maximum - possible displacement being 95°7 units or nearly ~, of an inch. When the photographs have been secured, the micrometric measurements which w.ll have to be performed consist in the determination of the sun’s semidiameter in units of the scale of the micrometer, the angle of position of the successive situa- tions of the planet on the disk, as shown on the series of photographs, and finally the distances of the centres of the planet and the sun. These data determine abso- lutely the chord along which the transit has been observed to within 0’"1; and an error of 1” in the measurement would give an error of only 0":185 in the deducea * Tn this micrometer, which is capable of giving radial distances, angles of position, and also rectangular coordinates, the accuracy of linear measurements does not depend on the 1* doubtful results given by a long run of a micrometer screw. 4 REPORT—1872. solar parallax. Moreover the epoch of each photographic record is determinable with the utmost accuracy, the time of the exposure being from 3, to 73, of a second or even less. Now, although the truth of the foregoing remarks will be fully admitted, it will yet be well to point out in this place the inherent or the supposed defects of the photo- graphic method. These defects may principally be comprised under the head of Possibility of Distortion; and the importance of an investigation into this source of error will appear at once obvious in all cases where the position of a definite point with reference to a system of coordinates has to be determined from measured photographs, especially in such a refined application of it as that which it will have in the determination of the solar parallax. The distortion of a photographic image, if such exist, may be either extrinsic or intrinsic—that is, either optical or mechanical. The instrumental apparatus for producing the image may produce optical irregularities before it reaches the sensitive plate ; or an image optically correct may, by irregular contraction of the sensitive film in the process of drying, and other incidents of the process, present on the plate a faulty delineation *. In general, two ways present themselves for clearing observations from errors. Either methods may be devised for determining the numerical amount of every error from any source, or by special contrivances the source of error may be contracted to such insignificant limits that its effect in a special case is too minute to exert any influence upon the result. Both these roads have been followed in the inquiry into the optical distortion of photographic images. As regards the first, let it be supposed that, as in the Kew instrument, the primary image is magnified by a system of lenses before reaching the sensitive plate. “The defects inherent to the optical arrangement will clearly affect every photographic picture produced by the same instrument; and hence a method suggests itself for determininz absolutely the numerical effect of distortion at every point of the field. Let us assume that the same object, which may be a rod of un- alterable and known leneth, be photographed in precisely the same manner in which celestial events are photographically recorded, the object being at a con- siderable distance ; it may successively be brought into all possible positions in the field of the photoheliograph, and the length of the image on the photograph may be measured afterwards at leisure by means of a micrometer. These lengths will change relatively wherever distortion takes place; but by laying down these varying lengths we shall obtain an optical distortion-map of the particular instru- ment; and tables may be constructed giving in absolute numbers the corrections to be applied to measurements of positions on account of the influence of optical distortion. In this way the optical distortion of the combined object-glass and secondary magnifier is ascertained. The chief source of distortion, if such exist, will be in the secondary magnifier ; and in order to ascertain its amount a reticule of lines drawn at equal distances upon glass may (as has been done recently by Paschen and Dallmeyer) be placed in the common focus of the object-glass and secondary magnifier, The required data are then immediately given by the measurement of the resulting pictures of the parallelograms on the reticule. Mr. Dallmeyer has ascertained in this manner that no sensible distortion exists in the secondary magnifier constructed by him. The truth of the principle being granted, it was applied to a preliminary series for finding the distortion which affects the Kew instrument, which is not nearly so perfect as those more recently constructed; and the results were so far satisfactory that, instead of a single rod, a proper scale, fifteen feet in length, representing a series of rectangles distributed over half the radius of the field, has been erected ; and the process of absolutely determining the optical distortion of the Kew photoheliograph is now in active progress, and will be used for the new instruments to be employed in observing the transits of Venus. * It has been proposed, in order to obviate any possible alteration of the sensitive surface, to use the Daguerréotype instead of the collodion process. The former, however, is so little practised, and, moreover, is so much more troublesome, that it does not seem to be advisable to adopt it, especially as the subsequent measurements would present greater difficulties than occur with collodion pictures. TRANSACTIONS OF THE SECTIONS. 4) The second method of dealing with optical distortion aims at total exclusion of . this source of error. It has been proposed by American astronomers, who intend taking part in the coming observations of the transit of Venus, to exclude the secondary magnifier, and, in order to obtain an image of sufficient diameter, to employ a lens of considerable focal length, say 40 feet, which would give an image as large as with the Kew photoheliograph—namely, 4 inches in diameter. As it would be inconvenient to mount such an instrument equatorially, it is proposed to fix it in the meridian in a horizontal position, and reflect the sun in the direction of its axis by means of a flat mirror moved by a heliostat. There can- not be any doubt about the fact that the image so produced would be nearly free from optical distortion, if the interposed mirror did not introduce a new source of error. The difhculty of producing a plane mirror is well known; and there is a difficulty in muintaining its true figure in all positions; there is also a liability of the disturbance of the rays by currents of heated air between the mirror and object-glass: moreover, with such an instrument position-wires could not be defined with sharpness on the photographs. On the whole, greater reliance may be placed on a method which admits the existence of a distorting in- fluence, but has at the same time means of checking and controlling it numerically. Great attention has been paid by me at various times to those effects of distortion which might arise from the process of drying. The results to which the experi- ments lead seem to prove that there is no appreciable contraction except in thickness, and that the collodion film does not become distorted, provided the rims of the glass plates have been well ground: this point is a fundamental one. But in such observations as that of the transit of Venus, no refinement of cor- rection ought to be neglected; hence fresh experiments will be undertaken to set at rest the question whether distortion of the film really takes place when proper precautions are taken. This will be done both by the method I have employed before, and also in accordance with M. Paschen’s proposal to measure images of such reticules as above described: this reticule might, as he has sug- gested, be photographed during the transit of Venus, so that each plate would thus bear data for the correction due to unequal shrinkage, if such were to take place. It has been objected by some astronomers who have casually examined solar photograms that the limb of the sun appears, as a consequence of the gradual shading off, even under a small magnifying-power, not bounded by a sharp contour; but the measurements of such photograms which have been made during the last ten years, of pictures taken under the most varying conditions which influence definition, have proved that even the worst picture leads to a very satisfactory determination of the sun’s semidiameter and centre; moreover an independent examination of this question by M. Paschen gave as the result that the mean error of a determination is only + 0-008 millimetre with a sun-picture of 4 Paris inches in diameter; this corresponds to + 0-155, and it is nearly three times less than that resulting from a measurement with the Kénigsberg heliometer. Nevertheless it will be seen from the foregoing remarks that I have not hesitated to arouse your attention to the fact that Astronomical Photography is about to be put to the severest test possible in dealing with such a fundamental problem of astronomy as the determination of the sun’s distance from the earth. An intimate knowledge of the subject, however, and experience with respect to work already accomplished in the Kew ten-year solar observations, inspire me with a confident anticipation that it will prove fully equal to the occasion. So much for performances to be looked forward to in the future: now let me briefly review what Astronomical Photography has already undoubtedly accom- lished. dl In the first instance the possibility proved of giving to the photographic method of observation a trustworthiness which direct observations can never quite obtain, will render the results of our discussion of the ten years’ solar observations at Kew more free from doubts than those observational series on the Sun’s spots which have preceded ours. The evidence of a probable connexion between planetary posi- tions and solar activity, and the evidence which we have published on the nature of spots as depressions of solar matter, could never have been brought forward but for the preservation of true records of the phenomena through a number of years ; 6 REPORT—1872. while the closer agreement of the calculated results in reference to solar elements is itself evidence of the intrinsic truthfulness of the method, and gives the highest . promise that our final deductions, which will be completed in the course of the ensuing year, will not be unworthy of the exertions which I, in conjunction with my friends B. Stewart and B. Loewy, have constantly devoted to this work during a period of fully ten years. Not only will some doubtful questions be set finally at rest by it, but new facts of the greatest interest will result, bearing on the laws which appear to govern solar activity. By nothing, however, would the claims of photographic observation, as one of the most important instruments of scientific research, seem to be so thoroughly well established as by the history of recent solar eclipses. It will be recollected that in 1860, for the first time, the solar origin of the prominences was placed beyond doubt solely by photography, which preserved a faithful record of the moon’s motion in relation to these protuberances. The photographs of Ten- nant at Guntour, and of Vogel at Aden, in 1868, and also those of the American astronomers at Burlington and Ottumwa, Iowa, in 1869, under Professors Morton and Mayer, have fully confirmed those results. In a similar manner the great problem of the solar origin of that portion of the corona which extends more than a million of miles beyond the body of the sun has been, by the photographic observations of Col. Tennant and Lord Lindsay in 1871, set finally at rest, after having been the subject of a great amount of discussion for some years. The spectroscopic discovery in 1869 of the now famous green line, 1474 K, demonstrated undoubtedly the self-luminosity, and hence the solar origin of part of the corona. Those who denied the possibility of any extensive atmosphere above the chromosphere received the observation with great suspicion ; but in 1870 and again in 1871 it was fully verified. So far, therefore, the testimony of spectroscopic observations was in favour of the solar origin of the inner corona. Indeed the observations of 1871 have proved hydrogen to be also an essential constituent of the ‘‘ coronal atmosphere,” as Janssen proposes to call it,—hydrogen at a lower temperature and density, of course, than in the chromosphere. Janssen was further so fortunate as to catch glimpses of some of the dark lines of the solar spectrum in the coronal light, an observation which goes far to show that in the upper: atmosphere of the sun there are also solid or liquid particles, like smoke or cloud, which reflect the sunlight from below. Many problems, however, even with refer- ence to the admittedly solar part of the corona, are unsettled. The first relates to the nature of the substance which produces the line 1474 K. Since it coincides with a line in the spectrum of iron, it is by many considered due to that metal ; but then we must suppose either that iron vapour is less dense than hydrogen gas, or that it is subject to some peculiar solar repulsion which maintains it at its ele- vation; or other hypotheses may be suggested for explaining the fact. Since the line is one of the least conspicuous in the spectrum of iron and the shortest, and as none of the others are found associated with it in the coronal spectrum, it seems natural, as many have done, to,assume at once thatit is due to some new kind of matter. But the observations of Angstrim, Roscoe, and Clifton, and recently those of Schuster regarding the spectrum of nitrogen, render it probable that elementary bodies have only one spectrum ; and since in all experimental spectra we necessarily operate only on a small thickness of a substance, we cannot say what new lines may be given out in cases where there is an immense thickness of vapour ; and hence we cannot conclude with certainty that because there is an unknown line in the chromosphere or corona, it implies a new substance. Another problem, the most perplexing of all, is the reconciliation of the strangely discordant obser- vations upon the polarization of the coronal light; but I will at once proceed to the points on which photography alone can give us decisive information. The nature and conditions of the outer corona (the assemblage of dark rifts and bright rays which overlies and surrounds the inner corona) was very incom- pletely studied ; and the question whether it is solar was not finally settled in the opinions of astronomers of high repute. Some believed it to be caused by some action of our atmosphere ; and others supposed it due to cosmical dust between us andthe moon. The bright light of the corona and the prominences most undoubtedly cause a certain amount of atmospheric glare; and although it is difficult to see how TRANSACTIONS OF THE SECTIONS. 7 this is to account for the rays and rifts, it would be rash to deny that it may do so in some manner yet to be discovered. Itis quite certain that some of the phenomena observed just at the beginning and end of totality are really caused by it. A light haze of meteoric dust between us and the moon might give results much resembling those observed ; but when we come to details this theory seems to be doubtful. _ Here photography steps in to pave the way out of the existing doubts. If the rays and rifts were really atmospheric, it would hardly be possible that they should present the same appearance at different stations along the line of totality; indeed they would probably change their appearance every moment, even at the same station, If they are cislunar, the same appearances could not be recorded at distant stations. It is universally admitted that proof of the invariability of these markings, and especially of their identity as seen at widely separated stations, would amount to a demonstration of their extraterrestrial origin. Eve-sketches cannot be depended on ; the drawings made by persons standing side by side differ often to an extent that is most perplexing. Now photographs have, undoubtedly, as yet failed to catch many of the faint markings and delicate details; but their testimony, as far as it goes, is unimpeachable. In 1870, Lord Lindsay at Santa Maria, Professor Winlock at Jerez, Mr. Brothers at Syracuse, obtained pictures some of which, on account partly of the unsatisfactory state of the weather, could not compare with Mr. Brothers’s picture obtained with an instrument of special construction*; but all show one deep rift especially, which seemed to cut down through both the outer and inner corona clear to the limb of the moon. Even to the naked eye it was one of the most conspicuous features of the eclipse. Many other points of detail also come out identical in the Spanish and Sicilian pictures ; but whatever doubts may have still existed in regard to the inner corona were finally dispelled by the pictures taken in India, in 1871, by Colonel ‘Tennant and Lord Lindsay’s photographic assistant, Mr. Davis. None of the photographs of 1871 shows so great an extension of the corona as is seen in Mr. Brothers’s photograph, taken at Syracuse in 1870; but, on the other hand, the coronal features are perfectly defined on the several pictures, and the number of the photographs renders the value of the series singularly great. The agreement between the views, as well those taken at different times during totality as those taken at different stations, fully proves the solar theory of the innercorona. We have in all the views the same extensive corona, with persistent rifts similarly situated. Moreover there is additional evidence indicated by the motion of the moon across the solar atmospheric appendages, proving in a similar manner as in 1860, in re- ference to the protuberances, the solar origin of that part of the corona. Tt will be well here to mention a difficulty which occurs in recording the fainter solar appendages, namely the encroachment of the prominences and the corona on the lunar disk when the plates have to be overexposed in order to bring out the faint details of the corona. It is satisfactory to find that whenever a difficulty arises it can be mastered by proper attention. Lord Lindsay and Mr. Ranyard have successfully devoted themselves to experiments on the subject. They tested whether reflections from the back surface of the plate played any part in the production of the fringes: for this purpose plates of ebonite and the so-called non- actinic yellow glass were prepared; and it was immediately found that the outer haze had completely disappeared in the photographs taken on ebonite, while on the yellow glass plates it is much fainter than on ordinary white glass plates. By placing’a piece of wetted black paper at the back of an unground plate, the outer haze was greatly reduced; but by grinding both the back and the front sur- faces of a yellow glass plate, and covering the back with a coating of black varnish, it was rendered quite imperceptible, thus showing the greatest part of the so-called photographic irradiation to be due to reflection from the second surface. * Mr. Brothers had,.in 1870, the happy idea to employ a so-called rapid rectilinear photographic lens, made by Dallmeyer, of 4 inches aperture and 30 inches focal length, mounted equatorially, and driven by clockwork; and he was followed in this matter by both Col. Tennant and Lord Lindsay in 1871. The focal image produced, however, is far too small (<8, of an inch, about); therefore it will be desirable in future to prepare lenses of similar construction, but of longer focal length and corresponding aperture. 8 REPORT—1872. Tn connexion with the solution of the most prominent questions connected with the solar envelopes, it may not be without great interest to allude to another point con- clusively decided during the last annular eclipse of the sun, observed by Mr. Pogson on the 6th of June of this year, as described by him in a letter to Sir George B. Airy. In 1870 Professor Young was the first to observe the reversal of the Frauenhofer lines in the stratum closest to the sun. Now, in 1871 doubts were thrown upon the subject. It appears that the reversed lines seem to have been satisfactorily observed by Captain Maclear at Bekul, Colonel Tennant at Dodabetta, and Captain Fyers at Jaffna. The observations of Pringle at Bekul, Respighi at Paodoxottah, and Pogson at Avenashi were doubtful; while Mosely at Trincomalee saw nothing of this re- versal, which is, according to all accounts, a most striking phenomenon, although of very short duration. Mr. Lockyer missed it by an accidental derangement of the telescope. The reversal and the physical deductions from it are placed beyond doubt by Mr. Pogson’s observations of the annular eclipse on June 6th. At the first internal contact, just after a peep in the finder had shown the moon’s limb lighted up by the corona, he saw all the dark lines reversed and bright, but for less than two seconds. The sight of beauty above all was, however, the reversion of the lines at the breaking-up of the limb. The duration was astonishing—five to seven seconds; and the fading-out was gradual, not momentary. This does not accord with Captain Maclear’s observations in 1870, who reports the disap- pearance of the bright spectrum as “not instantly, but so rapidly that I could not make out the order of their going.” Professor Young again says that “they flashed out like the stars from a rocket-head.” But discrepancies in this minor point may be accounted for by supposing differences in quietude of that portion of the sun’s limb last covered by the moon. The mention of the solar appendages recalls to mind another instance in which photography has befriended the scientific investigator. I allude to the promising attempt which has been made by Professor Young to photograph the protuberances of the sun in ordinary daylight. A distinct reproduction of some of the double- headed prominences on the sun’s limb was obtained; and although asa picture the impression may be of little value, still there is every reason to believe, now that the possibility of the operation is known, that with better and more suitable appa- ratus an exceedingly valuable and reliable record may be secured. Professor Young employed for the purpose a spectroscope containing seven prisms, fitted to a telescope of 63-inch aperture, after the eyepiece of the same had been removed. A camera, with the sensitive plate, was attached to the end of the spectroscope, the eyepiece of which acted in the capacity of a photographic lens, and projected the image on the collodion film. The exposure was necessarily along one, amount- ing to three minutes and a half. The eyepiece of the spectroscope was unsuitable for photographic purposes, and only in the centre yielded a true reproduction of the lines free from any distortion. ©’ or 5a’ where D=N—a’. Ex, gr. m=3 gives ,_ (8N+a?)a+f? 3N+a? * N= enter exactly, a — swt ty very nearly (since a?=N nearly), 38N +a? 2 SS = T Biss Cat jeciey a CS ao heres (A) as 3 must necessarily be very small indeed. Now this plainly agrees with Dr. at 1 Hutton’s elegant formula (D), given further on, for approximating to N” when n= 2. But we can approximate to N?* still more rapidly than by Dr. Hutton’s rule ; for by taking m=5, we find a(a'+10Na?+5N?) +f° N?+10Na?+5a* _o(N+a- Qc? = 5(N+@y—QN) *+ GN: or 5(N +a?)?— (2a)? ‘nan 5(N+a??—(2N)? N= exactly, . oe =a'+f' very nearly (since a?=N nearly), ppticdtly sr tae Min sa he tars Fate bh at see CE Now this last new and elegant formula approximates to N? much more closely than the above-mentioned formula of Dr. Hutton, since the error or supplementary term 5) ‘3 2 —_ = = - re, is obviously much less than rt its value or amount when Dr. Hutton’s rule is used. Ev. gr. To find V3. Let us take a=2, and as N is here =8, we find by our new formula . 5x??? 5 362 = 5x ae 2=209 nearly ; vi here omitted, viz. 172, 3 14 REPORT—1872, : 362\2 a sap, sete 362 . 5 : in fact (sao) =3+ oop)? indicating that 509 18 nearer to 73 than any rational fractior whose denominator is less than 209. On Cube Roots. It is plain, as before, when m is a positive integer, that (N?3—a)”, when expanded by the binomial theorem, has always the form AN?+BN? +6, since (N3)?=Ni, (N2)°=N, (N3)4=N.N3, (N3)5=N.NE &e. Now take a, as before, by trial or guess, so that N?—a shall be a small fraction f<33 fe! fr= (N?—a)™ =AN?+BNI4C; and for another integer m’ we haye f™ =(N?—a)” =A'N'+BNF4C. Now, by eliminating N? from these two equations, we easily find N?=(A/C—AC’+Af™ — A'f”) +(AB'—A’B) exactly, and therefore _ A’C+AC' ~ ABI A’B Ex. gr. Taking m=5 and m'=7, we readily find Nia LNV+105N%0?+120Na° + 11a? N?+ 60N?a°+147Na’+35a° so, if a@=N-+D, then Nia 2N(a'—2D)?+ D*(6a°+5D) 3N (18a? —D)?+-141D?a*— D* To find ¢/29, take a=3; then D=a°—N, .*. here =—2; and then our last for- mula gives (247)24-4(162) x 87 (247)? +4(152 = * 903 — yeu . 12=3-0723168 29° = 87(488)? 141 X 4x 2748 pass which is correct to its last decimal figure 8. very nearly. . @ very nearly ; da nearly. 5... «110 opine uo) u Easy Demonstration of Dr. Hutton’s elegant formula for approximating to N*, with an important’ Remark or Estimate of the degree of accuracy attained by means of its use and application. nS Let a be the assumed near value of N", whose exact value is =a+«#; then, as N must =(ate)"=a"+na"~ e+ ead ayy shila Ga a” —*x3 &e., sus N—a" ! bea n.n—I : Te ea re a’? xt &e. N—a” n q?—} for the first power of # in the preceding denominator and omitting the subsequent terms therein containing a”, x°, &c., we now find, more nearly, x 2(N—a’") = 2(N—a”) @ Qna+(n—1)(N—a") (n—1)N+(nt])a”’ and thus the corrected root ate=a(l +) comes out a and as w is very small, therefore it is nearly = . By substituting this value TRANSACTIONS OF THE SECTIONS. 15 2 i n as *% Bp 2 BO ePID 8 «oy (n—1)N+(n+1)a (n—1)N+(n+1)a” which is the elegant formula of Dr. Hutton, first given in his Fourth Tract in the year A.D. 1786. Now, to estimate the degree of accuracy attained by each new application of this elezant formula, let N=a”, so that a is the correct nth root of N, and a+a the assumed or guessed root whose error is 7; then the rule being applied, gives the corrected root j n—14(n-+1) (1+2)" n—1 2 ; =a(1+ D =) nearly. Now if the first two or three figures to the left be correct in a+a then the : fiiiigane i ae n2— relative error — will be it will be found that, after very considerable reductions, we have q the result that if ao es 2 5 2 ii e~ “dz, u being written for 22+ +, and also by certain series given in the ej fee 2a? (2a*)* — Te 02" (a —2)(n—4).. 0d 2 NS and ai (202)? as a” ae rhe “ ae a (n+2)(n+4).1,2 °"”’ then a2 pa x 3 v e Cie Fh IS Ba a a 0 [The details of the transformation indicated above are, to a great extent, given in the ‘ Philosophical Magazine,’ for June 1872 (vol. xiii. p. 433 &e.). The original q series are given at the top of page 434, and their transformations (taking 7 =) at the bottom of the same page, while U and V are merely (2) and (3) of page 435, 2a being written for 8, as is done throughout. The following errata should be noticed in the formule as they stand in the ‘Philosophical Magazine,’ viz. the factor 8" is accidentally omitted from the values of R and S given at the foot of page 434, and the factor 2 is omitted in the denominators of the second term in (2) and (3) (it should be yee also in (2) 6° should be 4°. None of these A(n+2 slips affect the subsequent work, for they are treated as if in their correct forms, not as printed. | Resuming (2), it remains to determine A and B. By putting a=0, we obtain at once A=3T es Let B= (x), and transform (2) by taking © for »; we thus 2 v find cs ee L Poesia doa (5) a" U+g@v. ie hs fale 3) 0 vat But. this integral is the same as the integral in (2), with the sign of x changed; ‘therefore, observing that a change of sign in » turns U into V, and vice versd, we see that the right-hand side of (3) also * Quarterly Journal of Pure and Applied Mathematics, yol. xi, p. 267. TRANSACTIONS OF THE SECTIONS, 47 =1P (—3)V+0(—2) a-AU ; whence it follows that g(n)=ar (—2), R n—1 oe The ] 4 (." oT Hdomy.{r(tyurer(—-2¥v], 2... & 2 and the formula in question. When n=27+1, it will be found that this gives, after use of the formula T(m) T1—m)= = and reduction, as the value of the integral T ign n 0 (o- Geer] (5 " (awh? which, by means of the formule in the Number of the ‘ Philosophical Magazine’ last quoted, is readily identified with (1). The form of (4) affords the reason why the usual methods fail to give the value of the integral, as it shows that the result is not generally expansible in integer powers of a. Generally, therefore, rr) ze, boa? “| : ie i * dv=ar (3) {i+ pete. be*ear(—2)an{ 1424} 20+... | “ But when » is a positive or negative odd integer, it is enough to take only the ter- minating series, and ignore the other altogether ; a more complete explanation of the reason for this than is given here can be gathered from the paper in the ‘ Philoso- hical Magazine.’ If x = a positive or negative even integer, the series for U or V ecomes infinite, and then one of the series involves loga as a factor (see Euler, Cale. Integ. vol. ii. chap. vii.). Even the partial discussion of this case must be omitted in this abstract, On the Function that stands in the same Relation to Bernoulli’s Numbers that the Gamma-function does to Factorials. By J. W. L. Guaisuer, B.A., F.RAS, It is always a matter of some interest to regard a series of constants as particular values of a continuous function, which function can usually be exhibited as a de- finite integral. The problem is of course indeterminate, as through a series of ea at finite intervals from one another an infinite number of curves can be | rawn ; but, as in the case of the Gamma-function in its connexion with the factorial = 1.2... 2, there is usually but one curve, which, in an analytical point of view, stands in this relation. It seems, therefore, worth while to investigate the function connecting Bernoulli’s numbers ; and this is readily effected as follows. Denoting by B, the nth Bernoulli’s number, we have 2(1.2.8...2n) ees | B= (Qn) {itget gt} prot me +e—i7t + 7 y dt b © {2n—1 zg t dt & =4n ( ; ) | AG i] He Ss ° P) 8 —— od 18 REPORT—1872. the expression in question, which gives a value for B, when n is fractional. In all cases, therefore, the formula is rat) 5, 1, 1 Bu= (2m)*” \lt ae tae tt. ee Oey os (1) The first four Bernoulli’s numbers are }, so, #5) vo, after which they increase rapidly, so that there is a minimum between B, and B,. As this minimum point is the only intrinsic point of interest on the curve y=Bz, the following Table was calculated of values of By in its vicinity :— a. 1B - a. By ° 2:0 0:0333333 3:0 0:0238095 2:1 0:0309658 3:1 0:0239930 2:2 0:0290652 32 0:0243304 2°3 0:0275461 3:3 0:0248228 2:4. 0:0263448 3 0:0254741 25 0:0254182 35 0:0262918 2°6 0:0247149 36 0:0272845 2:7 0:0242228 37 0:0284668 2:8 0:0239167 38 0:0298548 2:9 0:0237822 39 0:0314688 4:0 00333333 From Lagrange’s formula, that if A, B, C be three values corresponding to ar- guments a, b, c, then X=A (€—5)(@—0) B (@—2)(@—4) +9 (@—@)(«—b) (a=b)(a—e) *~ (6—e)(b=a) | (ea) (e-8)’ it follows that if A, B, C are three values in the neighbourhood of the minimum, then 2, the argument of the minimum, _(P—e*)A+(e—a") B+ (@—B)C , (6—c)A+(ce—a)B+(a—b)C ” and by deducing the value of x from 2°8, 2-9, and 3-0, and also from 2-9, 3-0, and 3:1, it is found that the minimum corresponds to =2'93...; and therefore, by the usual interpolation-formula, the minimum value =:02377.... The values in the Table were calculated from the formula (1) expressed in the modified form Byte Garay esta + he ate) Ths 8 ae 978 For «=2:1 it was necessary to include terms as far as (35) vie » for 2-2 as far as 1\2 e (5) *, and ultimately for «=4 only as far as e “The calculation was per- formed in duplicate, and the accuracy of the values is apparent on forming the 5th differences. The values of log I(x) were deduced from egendre’s Tables, It may be noted that, by means of the formula 1 somewhat different form may be obtained for By ; for we have B= Ent) ot oe vice dee (2x)"" (Q* =O" 2p , a =e. “ss TRANSACTIONS OF THE SECTIONS. 19 and are ee esa : 6 DHS)...’ so that p, EQnt)) 1)"B*-1)(G—I... a= (24)” (F--He ia i 7 2, 3, 5,..., being the series of prime numbers, On the Law of Distribution of Prime Numbers. By J. W. L. Guatsumr, B.A., F.RAS. In the ‘Philosophical Magazine ’ for July 1849 the late Mr. Hargreave proved two results of great interest in the theory of numbers, viz. that the average distance between two primes about the point « of the ordinal series was log, a, and that the number of primes between 2’ and 2 was very nearly liz’—lia, liv being the d= | A result practically th Gea result practically the same was also arrived at by Tchebycheff, Petersburgh Transactions, 1848 (see ‘ Philosophical Magazine,’ August 1854). The general truth of these results was verified by Hargreave for a number of ranges among numbers less than a million ; but in only one case did he compare the numbers given by the formule with the numbers counted above this limit. The means for making this comparison are afforded by Burckhardt’s Tables, which give the least divisor of every number not divisible by 2, 3, or 5 from unity to three millions, and Dase’s Tables, which do the same for numbers between six millions and nine millions. The intermediate three millions, although existing in manu- script in the library of the Berlin Academy, have not been published. Burckhardt’s Tables were published in 1814-17, and were therefore accessible to Hargreave; but Dase’s have only been published since 1862. By means of these Tables, of course all the primes included within their limits can be found, as their “least factors” being themselves, they are denoted in the Tables by a bar. I have therefore had all the primes in every hundred of the six millions over which the Tables extend counted, and have also calculated the numbers given by the formule; and the results, arranged in groups of 50,000 for two millions (viz. the second and the ninth), are given in the two Tables below. The second million was chosen in preference to the first for insertion in this abstract, partly because results derived from the counting of primes in the latter have been exhibited by Legendre, Hargreave, and others, and partly because the distribution is very anomalous near the commence- ment of the series of numerals. The numbers in the millions were divided into groups of 50,000, and 2" is written for brevity for z+ 50,000. In the first Table the numbers in the “ Primes counted’”’ column are the numbers of primes between w and 2’; thus there are 3635 primes between 1,000,000 and 1,050,000, &c. In the second Table the logarithm of the middle number of the group of the 50,000 was taken as the logarithm for the group, and the “‘ Average interval between the primes” was found by dividing 50,000 by the corresponding number in the “ Primes counted ” column of the first Table, the average intervals between two primes in the group from 1,000,000 to 1,050,000 being 13°76, &c. The logarithm-integral is only a transformation of the exponential integral, the relation between the two being li e*=Ei 2; and by the use of Taylor’s theorem we find logarithm-integral of x, viz. liz= . Recah on h? e e hs e e 2 e” Bi@e+h)—Hieah +25 (5-5 )tp55 (Sota )tee 20 REPORT—1872. ri iffer- ie A : me lia’—lia. Beda aaa | is lia'—lie. 1,000,000 | 3613 3635 —22 | 8,000,000 | 3145 1,050,000 3600 3580 +20 | 8,050,000 3144 1,100,000 3589 3589 8,100,000 3143 1,150,000 3577 3936 —59 | 8,150,000 3141 1,200,009 3567 3530 +3 8,200,000 3140 1,250,000 3507 B551 + 6 | 8,250,000 3159 1,300,000 8547 3522 +25 | 8,800,000 3158 1,850,000 3538 3579 —41 | 8,550,000 3137 1,400,000 3529 3501 +28 || 8,400,000 | 3135 1,450,000 3520 3526 — 6 | 8,450,000 | 5154 1,500,000 38512 3508 + 4 | 8,500,000 3133 1,550,000 3504 38465 +39 || 8,550,000 3132 1,600,000 34956 3498 — 2 8,600,000 3131 1,650,000 3489 3507 —18 / 8,650,000 3130 1,700,000 | 3482 3468 +14 | 8,700,000 3129 1,750,000 | 38475 3465 | +10 | 8,750,000 3127 1,800,000 3468 3470 — 2 | 8,800,000 3126 1,850,000 | 3462 3487 —25 |, 8,850,000 | 3125 1,900,000 3455 3473 —18 || 8,900,000 3124 1,950,000 | 38449 34380 +19 |) 8,950,000 3123 Total ....) 70429 70420 + 9 | Total ....) 62676 | | Average inter- | x+z2' |val between two r+z' es log “he consecutive | es jlog—5 primes. | 1,000,000 13°84 13:76 8,000,000 15:90 1,050,000 13°89 13:97 | 8,050,000 15:90 1,100,000 | 13:98 13°93 8,100,000 15:91 1,150,000 | 13-98 3°75 8,150,000 15:92 1,200,000 14:02 14:16 8,200,000 15-92 1.250,000 14-06 14-08 8,250,000 15:93 1,300,000 14-10 14-20 8,800,000 15:93 1,350,000 14:13 13:97 8,350,000 15°94 1,400,000 14:17 14:28 8,400,000 15°95 1,450,000 14:20 14:18 8,450,000 15:95 1,500,000 14 24 14:25 8,500,000 15°86 1,550,000 14:27 14:43 8,559,000 15:95 1,600,000 14:3 14-29 8,6C0,000 15:97 | 1,650,000 14:33 14-26 8,650,000 15°98 1,700,000 14:36 14-42 8,700,000 15:98 1,750,000 14:3! 14-43 8,750,000 15:99 1,800,000 14-42 14-41 8,800,000 15-99 1,850,000 14°44 14:34 8,850,000 16:00 1,900,000 14:47 14:40 8,900,000 16:00 1,950,000 14:50 14-58 8,950,000 16:01 i Primes | Differ- counted. | ence. 3121 +24 3129 +15 3127 +16 ol74 —33 3161 —21 3122 +17 3171 —33 3114 +23 3092 +43 3153 —19 3160 —27 3166 —34 3129 + 2 3152 —22 31389. | —10 3160 —33 3108 +18 8112 +13 3135 —l1] 3135 —12 62760 —84 Average inter- val between two consecutive primes. 16:02 15°98 15:99 15°75 15°82 16:02 15°77 16:06. | 16:17 15-86 15°82 15-79 15°98 15°86 15°93 15°82 16:09 16:07 15:95 16:95 TRANSACTIONS OF THE SECTIONS, 2] collecting together all the coefficients of me £ ee Fagan wh he” h3 e7 x 222 383 x? Z and therefore ; log, (1+) ; | log, (1+ =) } B . 4 ieee sod y pif!) y Hy) —Hy= tog — 2 | —Tog,y ato ogg et? an extremely convenient formula for calculating from Hargreave’s principles the approximate number of primes between limits. The last-written formula was, of course, deduced from the previous one by taking e"=y and e*t*=y+h, In the Tables k=50,000, and for y=1,000,000 the value of the second term only amounted to 6-2, and the third 0:2; for y=1,950,000 the second term was 3°2, and the third insensible, while for y=8,000,000 the second term was only 0-6; so that the first two terms were practically sufficient for the second million, with the interval of 50,000, and the first alone for the ninth million. It is impossible, in a brief abstract x log a—1:08366 &e.; but the author hopes to publish the values for the other millions elsewhere. The results given in the two Tables above were calculated or counted in duplicate throughout ; and it is believed that none of the values of liz’—liz will be found wrong by so much as a unit, though an error of this amount is just possible. In the total, which was formed merely by adding the numbers in the Jia’ —lix column, of course a somewhat greater error is possible by accumulation. It may be conve- nient here to state that 1i(1,000,000)=Wi(13-81551)=78627:2. ...; 11(1,050,000) =Hi (13°86430) = 82239°9....; li (1,100,000) = Ei (1391082) = 85840-2....; li (1,150,000) = Hi (13-95527) =89428'7,,., These values were not obtained from the first by means of the above Table, but were each calculated independently from the semiconyergent series : ae | Eiz=e* etet like the present, to notice the agreement with Legendre’s formula Teepe 2 8 ell 2) in: x + at = x Hargreave has given a formula which is no doubt a particular case of that in this aper (though I have not yet compared them) ; but either some of his constants must fave been erroneous, or he must have made errors‘of caiculation, as all the numbers given in the Table on page 48 of the ‘ Philosophical Magazine’ for July 1849, which was calculated by means of it, seem to be more or less inaccurate (see ‘ Philoso- phical Transactions,’ 1870, p. 586; the arguments are identical, as, in fact, Hargreave has taken integer arguments of the exponential integral, viz. Fil, Ei2, &c.). It may be added that the number of primes between 1,000,000 and 2,000,000 was computed by Hargreave and found to be 70,430, which differs by only a unit from the value in this paper (which value, as before remarked, could very well have been inaccurate by even more than this amount) ; and this completely verifies the accuracy of the numbers in the li x’—liv column of the first Table between two and three millions. Hargreave (Philosophical Magazine, August 1854) found the number of “ Primes counted” up to one million and between two and three millions to be 78,493 and 67,751 respectively ; while the formula gave 78,626 and 67,916, the discrepancies being much greater than that which is here found for the second million, where the difference was only 9. The numbers I have found for the “Primes counted” differ from Hargreave’s; but as they have as yet been counted but once, no great reliance can be placed on them. The formula values I have not yet calculated. On a Verification of the Probability Function. By J. HE, Hirearn, U.S. Coast Survey. 22 REPORT—1872. On Tridiametral Quartan Curves. By F. W. Newman. ProsieEM. To find the conditions that a Quartan may have 3 Diameters. That it may have one, the equation must admit the form ay +Xiy=X,, where X,, means a function of x of the mth degree. Let r?=2?+y?; then we may write ar*+ (Aa’+ Bret C)r?=hat+le?+ma?+netp. This form will not be changed if we change the origin to any point in the axis of y; hence, if there be a second diameter, we may may suppose it to pass through the origin, which we treat as a Pole, making e=rcosw, y=r sin p. Then art+ (Ar’ cos? w+ Br cos p+C)2= kr* cosy + Ir? cos’ y+ mr? cos? y+nr cos p+p=0, which by the routine of trigonometry is expressible as {a—3k+3(A—A) cos2—gh cos 4p tr + {(B— ZI) cos p— Zl cos 3p hr? : + {(C— im) — 3m cos Wp tr?=nr cos p+p. This is the equation of every Quartan which has so much as one diameter. Tn order that the line expressed by p= y may be anew diameter, it isnecessary and it suffices that the same equation should result by substituting ~=y+o, and y=y—a, where y is a definite constant, 7, w the variables of the equation. Put ~=y+o; then in order that + may give the same result, the terms concerned must vanish in the coefficients of 7, 7°. 7°, x separately. It must be observed that the assumption y=0 or y= 180° is useless; and y=90° leads us to two rectangular diameters, not to three. Hence we must avoid to suppose sin y=0 or sin 2y=0. Now (1) zrsiny.sino=0, .. n=0; (2) msin 2y sin 2o=0, .. m=0; (3) in the coefficient of 7°, we need at once (B—2/)sinysino=0; j/sindy.sin3e=0. It is useless to suppose 7=0, B=0; for this, joined with m=0,n=0, reduces the equation to the Doubly Diametral. Hence our only useful results are sin 3y=0, B=3/; which leave B and / finite, (4) (A—A) sin 2y. sin 20=0, kh sin 4y sin 4o=0. We cannot make sin 4y=0, since we already require sindy=0. Hence nothing remains but 4=0, A=0, Thus the original equation is reduced to art+(Br+C)r?=4Ba*+p ; tendo jel) ends Soe (h) and from sin5y=0 we get two new diameters, defined by y=60° and y=180°. Thus the problem is solved. Originally, the assumption a=0 would have left our monodiametral curve still a Quartan. But after supposing A=0 and k=0, we cannot make a also =0 without reducing the equation to a Tertian. In fact it is easy to show that the conditions hereinvestigated yield the known Tertian 7'rijuga when we add the assumptiona=0. Writing «=r cos y, 42° =7°(cos 3y+3 cos W), we find ar*+Cr?=1Br cosdy+p, « 2 4 + « ys (8) which is the most general Polar Equation of Tridiametral Quartans. Again, solving (f) for 7*, and making a=1, since a must be finite, r+3(Br+C)= 7 {$Be°+7(Br+C)*+p}, Thus the general equation to rect. coords. has the form P+e+Bae+C's o {3Bio°+(Ble+C'y?+Et, 1. we (A) which has 3 Parameters, TRANSACTIONS OF THE SECTIONS. 23 If, however, C'=0 and E=0, the Polar equation becomes simply »=}B' cos 3y, which is a Starry Trijuga, admitting r=0. In general, the equation to rect. coords, falls under the class P+X.=V/X,, which is the highest form of those which I call Quartotertian. . : Ar*+Br?+C The Polar equation may be presented in the form cos 3}—=——_~3 The curve is evidently in every case finite, and the species must apparently change according as the equation admits the forms ar? cos 3y~¢= (72—b?) (7? —@) ,ar* cos8yp= (7?-++6?) (7° —c?), ar® cos 8 = (r?-+6")(7?+c?), or finally ar* cos d= (7? 6")? + c%, d . Eyidently x. =0, when sin 5y=0. If y=120°+ 4, cos 8y=cos 36. Hence the figure is Equilateral. On Quartan Curves with 3 or 4 Diameters. By F. W. Newman. This Memoir proposes and solves the Problems, in what case Curves of the Fourth Degree have 3 or 4 diameters. It briefly analyzes the forms of the Tridiametral Curves, under the heads which rise out of the general equation 2ar® cos Bv=r'+2b72+c=R: when R=r", or 2a cos5sy=r; when R=r'—£””, or 2ar cos 8y=7?—°; when R=7'@°r?; when R=7!—y'; when R=7*+y'*, and generally when R is essentially positive ; . when R=(7?—@)(7?—y"), which has 3 remarkable forms ; - when R= (7?+8")(7?—y*), which has 2 forms, according as 6? is>y? or j denoted by ¢, and p, respectively. = Now, to aid our conception in a process of theoretical reason- f}——————— ing, let us imagine an apparatus possessing certain qualities in Yj——4————— theoretic perfection, thus :— (ep Be D)s hos oN eS a a 12) ioe) = 19) - I ction [EL EPEIR) 2) S) 2) 7) 2) “ Pl ele eye Sahel hee la Bae: : Beas "a1aV 3 ¥ : E TIVANIVY , s Ca ae 3 ; : i 3 Slee? | 4B eilspPepres |e) sia]: i ee = ea ea (I) = IY (od res ee (oe ee eee PE TS (ee Bie | 2 ie le |) ee |e [als (oe deo lie OlF AISA la (aa leila l(4a}alola sa } ‘OL8T “TL8T EONS ji dete ne? | | we TRANSACTIONS OF THY SECTIONS, 5b Ice is rarely seen in Patras, and snow very seldom. Geraniums continue to flower all the winter. But all the winter there is an horizon of snow-capped mountain to the E. half of the compass, which snow is not entirely gone in the middle of July. The heat is great in July and August: last summer there were twenty days running when the maximum was never less than 90° nor the minimum than 70°. For further particulars see Tables. Clouds.—In the year 1871 there were 29 days on which no clouds of any sort were seen. mio? seh 3 no clouds were seen excepting those which clung about the mountains—days, that is, of uninterrupted sunshine. 182 5) 5 clouds were seen in the sky, most of which would be counted as decidedly fine days in England. 41 Jue the sky was entirely overclouded, so that no blue sky was seen alldaylong. Thirty-five of these were in January, February, November, and December. The extreme clearness of the atmosphere deserves attention. .A mountain in the island of Cephalonia, 5300 feet high, forms the western horizon, and is visible certainly half the days of the year. Sois the Parnassidi range (8000 feet), distant forty miles; and this, when white with snow, is discerned by moonlight. The nearer mountains, ten, fifteen, and twenty miles away, are frequently quite distinctly - seen by moonlight without the aid of snow. Earthquakes are disagreeably common. The author has felt about thirty himself, - none of which have done more serious damage than to bring down flakes of plaster. _ Patras was once entirely destroyed, 540 A.D; but since then the severe shocks ————————— ss - rrt”—“‘i—sS haye been confined to the shores of the Gulf of Corinth and to the islands of Zante, Cephalonia, Ithaca, and Leucadia. The author has seen two brilliant Auroras (October 25, 1870, and February 4, 1872), both of a deep red colour. On the Advantages of keeping Records of Physical Phenomena connected with Thunder-storms. By W. pe FonviEtte. The author begins by referring to the importance of the records of luminous meteors made by the Association, and which have given rise to a great science, the future influence of which on astronomy it is impossible to determine. After having yeviewed the work of the Committee for Luminous Meteors, he shows that thunder- storm phenomena are practically far more interesting for us, as being more inti- mately connected with our personal welfare and security. Only in few disconnected cases do falling stars produce fatal results, while thunder-storms may have an important influence on our property, our health, and our lives. Captive balloons are spoken of by Arago as tending to enlarge the system of protection inaugurated by Dr. Franklin, so that an immense field may be said to be opened for inventions in this direction. The author showed, by quoting his correspondence, that in this very land the efficiency of lightning-conductors had been questioned, and that in Manchester a conference, held on the occasion of Kersall Church being struck, had arrived at the conclusion that lightning-conductors were worse than useless. The author referred to the use of the electric telegraph for giving warning to shipping, as practised by the Board of Trade. He alluded also to the steps taken by the French Government for having maps drawn of the course followed by thunder-storms. The author showed that, if the question is limited to the observa- tion of phenomena when places are struck by lightning, it is of great importance and magnitude. Quoting several newspapers, the author finds that not less than five or six cases of great scientific interest had occurred within a month in the county of Sussex, all of these being lost for science and forgotten for ever, if not roperly recorded. He is advocating no novelty, as a Committee of the French Pactituie had officially advised the French Government in 1823 to establish a _ yecord-of these cases, where a building-had been struck by lightning when supplied with a lightning-conductor. He explained how prevalent superstitions had pres 56 REPORT—1872. vented the French Government for a long while from giving force to the advice given by the French academicians. When these obstacles were partially removed the opportunity was lost for establishing it, and the suggestion quite forgotten. He thinks that the French Government of 1872 will take a more intelligent view of the question, especially if the British Association encourages them in doing so, by establishing some definite organization for the purpose, as he is himself a living proof of the interest felt now by the French Government in these matters, having been sent to England in order to report on the late thunder-storms which had been so remarkable. Would it not be in some respects unbecoming of a great nation like England, whose power has been unchecked, to take no interest in these casualties which are attracting the notice of a foreign people emerging from so many calamities ? On a Periodicity in the Frequency of Cyclones in the Indian Ocean south of the Equator. By Cuartes Metprum (Mauritius Observatory). One of the objects for which the Meteorological Society of Mauritius was esta- blished in 1851, was to obtain extracts from the Meteorological Registers of vessels visiting the harbour of Port Louis, especially of such vessels as had experienced bad weather in the Indian Ocean. Accordingly clerks were employed to copy all the log-books that could be rocured, " In 1853 the system of registration was remodelled. Instead of having the obser- vations contained in each log-hook recorded separately, all the observations in all the log-books for the same day were entered on the same page. As this system has been conducted without interruption to the present time, the Society has now a large collection of observations showing more or less the state of the winds and weather over the frequented parts of the Indian Ocean, in the form of a daily journal, during the last nineteen years; so that a person may find at once what weather prevailed on any day, or in any year, during that period, Together with the years 1851-52, therefore, during which the registers were differently kept, we have twenty-one years’ continuous observation from the meridian of Greenwich to 120° E., and from 23° N. to 45° 8. Adding to the information obtained by the Society throughout these twenty- one years, numerous observations collected by several persons for the previous four years (1847-50), we have a more or less complete record of all, or very nearly all, the cyclones which have taken place in the Southern Indian Ocean during the last twenty-five years; for Mauritius is so much in the track of these cyclones, and so much frequented by vessels in distress, and by others trading between the Colony and England, India, and Australia, that it is scarcely possible for any violent hurricane to happen without being noticed. Taking now, for the present, the area comprised between the equator and the parallel of 25° S., and the meridians of 40° and 110° E., and examining a Table of the cyclones that have occurred there from 1847 to 1872, it is found that some years have been remarkable for a frequency, and others for a comparative absence of cyclones. : The five years 1847-51 were characterized by cyclone-frequency. Then came a period of comparative calm (1852-57), which was followed by six years (1858- 63) remarkable for cyclones. The next five years (1864-68) showed a consider- able decrease ; and since 1869 there has been an increase, until, for the present year (1872), the number of cyclones is already (28th June) greater than in any year since 1861, What has now been said is not only borne out by the records of the Meteorological Society, which give detailed accounts of the hurricanes, but also, I have little doubt, by the books of the Docks and Marine Establishments. Especially in 1847 and 1848, and again in 1860-63, the harbour of Port Louis was at times crowded with disabled ships; whereas in the years 1855-57 and 1866-68 there were very few. It will ke seen that these years correspond pretty closely with the maxima and minima epochs of sun-spots, TRANSACTIONS OF THE SECTIONS. 57 For the present, I wish merely to call attention to the subject, in order that the connexion which I think exists between sun-spot-frequency and cyclone-frequency may be either verified or refuted by past or future observation. “It appears to me that there is more than a mere coincidence as to time. There are three maxima and two minima epochs of cyclone-frequency corresponding nearly, if not entirely, with similar sun-spot epochs. To examine the matter fully, it would be necessary not only to know the number of cyclones in each year, but also the extent and duration of each, and the force of the wind. Ifwe could thus get an expression for the annual amount of cyclonic energy, and could show that it varied directly as the amount of sun-spots, a con- nexion would be established. One violent hurricane, which lasted ten days and passed over thousands of miles, might have more valwe than half a dozen smaller and short-lived ones. However, having question, I have no doubt that the years rally, if not always, the years of gre traced a large number of the cyclones in of greatest cyclone-frequency were gene- atest cyclone-energy; and that the number of cyclones in a year is a fair expression of the cyclonic activity for that year. Now, taking the maxima and minima epochs of the sun-spot period and one year on each side of them, and comparing the number of cyclones in these periods, we get the following results ;— three-year Number of Total num- Cyclones in ber of Years. each year. Cyclones, 1847 NER ary Reg Mase 4 VIGRTMNG ¢ is saas.s «0 pi Sane olee See Be of cereaag . 15 NGA OW Prete ates em edatn- 5 SSD: 95), SMa oe, 4 TATINGD By Lay Aile gov es jist Note te utinsta Bert 8 STE AO Sate wre mare 1859 a Ft,e,00%8 P| MMII. a Ma aeh ack Oiea.4 LOGO «tisccesienks cc Bea wate card Lok jis De AR eee oo aes) SGGE osperctn: hevtteo areas 5 WVTITTG., io alee aie, eS LGin. HAR AA. ASE ML MSE aceon) 9 ja Perr cd Be a is EN 2 SOE ceca che ca ahenere aie Masi eos sosseeees HI dees dela ape borss datefeee ee 14. MSZ octets aieeearis tentee 7 Taking two years on each side of the solar-spot epochs, we get :— Number Total Years of Cyclones. number. (PSL Ms walkie enctt Sous wrest 4°) | REDO bate ireiatiec sais Aas 3 [ ie iad s.5;0 6 + 0/0, 0: glen otane oc a eh axe De Sitar 15 oy a aoa eee eee 3 l SOS rr Sea Meee 1] 1/2 a a ee 4) | 1850 d diicsoe coon oe nuE 5 | BPARIMG - 0:5 «5.0.0 sipiioun eka eb eli OO is eran anaes aoGitcae Se ede stains 32 ; ees minisyn, Fee Shem) eerhi Moe 8 | 1862 Ag iaoe oe are ti EOGD'. 7 Oy Seal Wis Meme 3 [ 1860 B Aci cihcuchnca wcities 5 | Minima .. hates Coe OL OO Te ae, Aeee eaee a tee 2 re eles rely 15 NEHA sis, SOURIS aye 2 STSHO! Cie ah ors hee ay 3 | 58 a REPORT—1872. Assuming that we have got a close approximation to the actual number of cyclones, and that the numbers fairly represent cyclonic energy, it is difficult to avoid the conclusion that the above Tables point to a definite law, and that Mete- orology, Magnetism, and Solar Physics are closely connected; for what holds good with regard to a large tract of the Indian Ocean, probably holds good with regard to other portions of the earth’s surface. Is it not probable, also, that if there is such a connexion as is here suggested between sun-spots or sun-cyclones (as they have sometimes been called) and earth- cyclones, there is a similar connexion between the sun-spots and cyclones in the other planets ? The Rainfall of Sussex. By Freprrtck Ernust Sawyer, of Brighton. The county of Sussex is divided by the South Downs into two meteorological districts—the coast district, which has a small rainfall and an equable climate, and the Weald, which has a much greater rainfall and an extreme climate. The causes of the increased rainfall in the Weald of Sussex are threefold: first, the Downs, which attract and condense the vapour in the rain-clouds which pass over them, causing it.to fall in the Weald as rain; secondly, the forests, which break the wind and assist in condensing vapour, the cutting-down of the Wealden forests for fuel, when iron was manufactured in the county, having, however, dimi- nished the rainfall in some parts; and, thirdly, the rivers, the beds of which form a path, up which rain-storms, and particularly thunder-storms, pass from the coast into the Weald, and also by condensation produce “ tidal showers.” The average coast rainfall is about 25 to 26 inches, whilst that of the Weald is nearly 33 inches. The greatest rainfall in the county is at Lynch, near Midhurst, the average there being about 38 or 39 inches. The least rainfall is at Pevensey, where the mean of thirty years was 24:07 inches. The comparison of the totals of rainfall on both sides of the Downs shows an increase in the totals in the Weald of from 20 to 50 per cent., owing to their influ- ence. At Worthing, on the coast, the mean of three years ending 1871 was 23°88 inches; and at Steyning, in the Weald, it was 34:25 inches, or very nearly 50 per cent. more. he greatest rainfall recorded in the county is 54:20 inches in 1852 at West Dean, the least at Pevensey in 1858, 13-11 inches. There does not appear to be much difference in the seasonal distribution of rain in various parts of the county. The low districts round Pulboro’, Arundel, Bramber, Henfield, and Lewes become’ inundated after heavy rains. Such inundations occurred in 1810, 1821, 1828, 1839, and 1847. Severe droughts occurred in 1834, 1847, and 1852, There is only one rainfall proverb peculiar to the county :— ‘When Wolsonbury has a cap, Hurstpierpoint will have a drap.” Wolsonbury Hill is a summit in the Downs, near Clayton; and when enveloped in clouds, rain may be expected at Hurstpierpoint. 2 Acoustics, On Musical Beats and Resultant Tones. By Ruvorr Kénte. On the Human Voice as a Musical Instrument. By G. VanpELevr Ler, nell TRANSACTIONS OF THE SECTIONS. 59 INsTRUMENTS. On the Mensurator, a new Instrument for the Solution of Triangles. By W. Marswam ApAms. The Mensurator is an instrument by which triangles may be solved; that is to say, when the necessary data are given, the instrument may be set according to them, and the values of the other parts read off. The author illustrated the use of the instrument by numerous examples, Ona new Hygrometer. By Groren Dinzs. The peculiarity of this instrument is, that the use of ether is altogether dispensed with, water only of a lower temperature than the dew-point being required: this is placed in a small reservoir.} By turning a tap, the water is allowed to pass through a closed vessel covered with THIN polished metal or black glass. As soon as the dew appears upon the surface of the metal or glass, the flow of the water must be stopped; and a thermometer, the bulb of which is enclosed in the vessel, shows the temperature of the dew-point. Using this instrument side by side with the dry- and wet-bulb thermometers, the author of the paper has come to the conclusion that (whatever Tables may be used) the latter can never be depended upon as giving more than an approximation to the dew-point. He also describes the aqueous vapour in the atmosphere as badly mixed ; and that masses of air very differently charged with moisture are rolling over the surface of the earth in the same manner as the clouds above, the difference being that they are invisible. On a Nautical Photometer. By J. Horxrnson, D.Sc. The photometers hitherto used for viewing distant lights, too faint for comparison with a standard candle, depend on the absorption of light by a coloured medium till the light is no longer visible. hese photometers are defective :—Ist, as they do not give the true factor by which the light is diminished in intensity ; 2nd, the absorbing medium is arbitrary, and must be arbitrarily defined; 3rd, the effects on red and white lights are not comparable. The photometer suggested consists of two suitably mounted Nicol’s prisms, which can be turned about a common axis till the iight is eclipsed. If x be the angle between the polarizing planes of the prisms, the light must be diminished 2 m Cos times to render it invisible, where m is a constant near unity depending on the reflection at the faces of the prisms. Nouveau Thermométre destiné a prendre les Températures de la Surface des Eaux Marines ow Fluviales. Par le Docteur Jansszy, J’ai ’honneur de présenter au meeting un thermométre d’un nouveau modéle, destiné a prendre la température de la surface de la mer ou des fleuves. Cet instrument dont j’ai déja publié une description dans les bulletins de la So- ciéte Météorologique de France, le 3 Décembre 1867, a été employé depuis par un grand nombre d’observateurs et a donné des résultats trés-satisfaisants, qui permet- tent de le considérer comme définitivement acquis & la science. La disposition nouvelle de cet instrument consiste en ce que le réservoir est lacé au milieu d’un pinceau de fils de chanvre. Ce pinceau est fixé a la garniture Ae bois ou de cuivre du thermométre ; il porte & sa partie supérieure une virole de plomb. Lorsque l’instrument est jeté a l’eau, la virole de plomb J’entrainant, il y pénétre rapidement et verticalement ; les fils de chanvyre s’écartent aussitét et le réservoir thermométrique se trouve alors en contact avec le liquide, dont il prend la température. En quelques secondes l’équilibre est atteint et on peut retirer le 60 REPORT—1872. thermométre au moyen deson cordon. Aussitét que V’instrument sort de l’eau les fils se réunissent, entourent le réservoir et conservent par capillarité une quantité assez considérable du liquide dont on youlait obtenir la température. La présence de ce liquide autour du réservoir permet de faire tout 4 son aise la lecture de 1’échelle, car je me suis assuré par des expériences multipliées que l’évaporation 4 la surface du pinceau, méme en présence du soleil et dans un air trés-sec, est impuissante & faire varier la température du réservoir avant un temps triple ou quadruple de celui qui est nécessaire 4 la lecture. Voici une expérience qui montre avec quelle lenteur le nouveau thermométre perd la température du bain dans lequel on I’a plongé, La température de V’eau était de 19° centigrade. Au soleil un thermométre ordinaire marquait 37°. Le thermométre a pinceaw fut plongé dans l’eau, marqua bientét 19°, fut retiré et exposé au soleil, Or, aprés 180 secondes il marquait 19-15 30 secondes il marquait 19-0 60 3 5 19-0 210 .; 5 19-2 90 if +4 19-0 270 ‘ 19:3 120 if ie 19-0 300 - i 19-4 150 3 .. 19-1 360 ‘ fs 195 Le temps nécessaire pour retirer le thermométre de l’eau et en faire la lecture Pp n’est jamais supérieur 4 15 secondes. Dans l’expérience rapportée le thermométre était resté & 19° pendant 120 secondes; c’est 8 fois plus de temps qu’il n’était néces- saire 4 la lecture, Températures de la surface de la mer prises par M. Giraud, de Marseilles a Alexandrie. Température de la mer donnée Dates Latitude | Long. Est ? Par le ther- Nord. de Paris. momeétre | Par le seau. @ pinceau. Février. 5 rs 19 9” soir 14-2 14:2 Spit Bide od 20 Midi 14:2 14:2 41 165 6 46 E. aed. £1 14:2 14:2 Or choinns 14:2 14:2 Minuit .. 14:3 14:3 oare ann 14:5 Sader 145 14:5 38 63 ll 44 21 Midi... sc 1455 145 Pasi vaays 145 14:5 Ca: 14:5 14:5 Minuit .. % a GMA. here 14:8 14:8 ODS Roe. 14:8 148 57 02 16 16 22 Midi 14:8 14:8 OUT aie ae 14°8 14:8 GU ick 14:8 14:8 Oh. kMihi ” 5) Minuit .. - x GREE ERG 15:0 15:0 Ona AN 155 155 * 25 Midi 15°8 15:8 35 02 21 10 * M. Giraud a fait plusieurs centaines d’observations présentant le méme accord. différences ne s’éléyent jamais 4 plus de 3, de degré. Le Se TRANSACTIONS OF THE SECTIONS. 61 C’est 4 l’occasion des travaux que j’ai exécutés 4 Santorin en 1867, que j’ai ima- giné ce thermométre pour prendre la température de l’eau de la mer prés du volean alors en activité. ’ P , Je m’en suis servi dans un voyage aux Acores en 1867, depuis Lisbonne jusqu’a St. Michel. Je l’ai également employé dans mes deux voyages aux Indes en 1868 et 1871. Or j’ai constamment contrélé les indications du thermométre 4 pinceau en pre- nant les températures par la méthode ordinaire, qui consiste, comme on sait, & puiser directement dans la mer un seau d’eau dans lequel on place un thermométre. Les deux méthodes se sont toujours accordées 4 ;1, de degré quand on opérait avec le soin nécessaire. A ma demande, M. Giraud, officier de marine frangais, a bien voulu prendre des températures de la Méditerranée pendant plusieurs voyages de Marseille 4 Alex- andrie. Cet officier avait aussi le soin de contréler les indications du thermo- métre & pinceau jeté 4 la mer par celles que le méme instrument dépouillé de son pinceau donnait dans un seau d’eau puisé au méme instant. On donne un fragment de ses résultats, p. 60. En résumé, le thermométre a pinceau 4 tres-bien soutenu de nombreuses épreuves depuis cing années, et on peut le considérer comme un instrument acquis & la science. On en construit beaucoup en France. On the Temperature-correction of an Aneroid. By Joun Pattirs, M.A. and Hon. D.O.L. Oxon., L.RS., Professor of Geology in the University of Oxford. Few instruments invented in modern days have found a more ready and general acceptance for ordinary observations of atmospheric pressure than the Aneroid; but for accurate weighing of the column of air it is not to be trusted without care- ful precautions, and a preliminary study of the particular instrument employed. The object of this communication is to explain a method by which an instrument which has been in frequent use for nine years, and is liable to enormous variation of reading by change of temperature, has been made to give accurate results, The instrument has a diameter of 1°9 inch, and weighs 1560 grains. It is quick and firm in its indications while kept in the same position and at the same tem- perature; but the reading is reduced if the position be changed from horizontal to vertical, and by any, however small, elevation of temperature. It has suffered many shocks, but is entirely uninjured by these and other misfortunes. Though divided only to ,\;inch, its indications can be recorded with entire confidence to zoo» and are, in fact, by a peculiar method of reading, written down by estimation to a+ _ Its scale is correct for a range of 24 to 31 inches. Held in the warm hand, or exposed to sunshine, the index turns sensibly to the left. Heated from 40° to 80°, the deviation exceeds three tenths of the baro- metric inch. By employing a hot closet the effect is augmented enormously, so that for one degree at 100° Fahr. the index retreats about ‘020 inch. After numerous and often-repeated comparisons with a standard barometer, at different atmospheric pressures and temperatures, the following summary of ob- served differences or corrections (e) to be applied to this aneroid, so as to make its indications agree with the mercurial instrument, as read at the same time, was adopted as a basis for calculation, The corrections are additive. 80} Temperature | Correction. Tahr, & 70 hh te lee roel Go" 80 0-420 | 70 0-300 a 60 0-200 | 50 0-130 | Ao" 40 0-080 1872. ie 6 S| 62 REPORT—1872. These numbers, examined by differences, indicate a formula whose principal term involves the square of the temperature. If they he projected as ordinates, a curve of parabolic form results, as given above, the vertex being pioced somewhere below 40°, where, probably, a curve of contrary flexure would begin. Assuming (r—n)? : the curve to be a parabola, 8B 1000 = the correction for temperature, and taking n=10° and 8B=:0837, the values of ¢ are given in the third column. Temp. Fahr. | « Observed. | ¢ Calculated. Difference. ° 80 "490 410 — ‘010 70 *300 301 +001 60 +200 209 +009 50 130 134 +004 40 ‘080 | 075 — ‘005 A still closer approximation is found by employing a more complete expression atXbr*+ter® 1000 80°, a=0, b=-03, e=:000445. The resulting corrections appear as under, from 90° to 30°, the utmost limits of probable observation in the British Isles. for the function of temperature, such as , in which, between 40° and Temperature. br. cre ¢ Ob’ ’rved. |e Calculated.| Difference. © 90 243 B24 aes 567 80 192 228 420 420 ‘000 70 Ate 2 OS "300 300 000 60 ‘108 ‘096 204 “200 +:004 50 ‘075 056 13 131 +001 40 048 028 080 ‘076 — 004 80 027 012 A Table constructed in accordance with this formula has been found, by much experience, to give very satisfactory results in measures of terrestrial elevation. The author has also investigated instruments compensated for temperature, and finds in some cases a curye-correction necessary for inequality of scale. Description of the new Marriotti Barometer. By Macnett Trtrorp. The Spiral Top. By Prof. Cu. V. Zuncrr. “ On a stand of brass, fastened to a board, a screw moves in a vertical direction on the upper end of the stand. The axis of the top, with its conical end, is put in a conical hole worked in the screw, and the other end lies in a similar conical hole ona appa fastened to the hoard vertically and in the same line as the screw. On the axis of the top is fastened a movable arm, with a screw and ball of brass that can be fastened at different distances from the axis of rotation. A double ring of brass to span a sheet of paper in it may be fastened on the screw, the plane of the paper being vertical to the axis of the top. The apparatus is then prepared to show the nutation of the axis and precession of the nodes by spinning it. The axis of the top describes a circle on the paper, on which an ellipse evolves, whose length of axis depends on the position of the arm on the axis and the distance of the ball screwed to it. Taking the brass arm with the TRANSACTIONS OF THE SECTIONS. 63 ball from the axis, and fastening the spiral wire to it, the top is prepared for another experiment. n the former experiment a circle is described if the velocity does not change ; but the friction and resistance of the air tend to diminish it ; and so with a decreasing velocity of rotation the angle of inclination of the top’s axis becomes changeable, and instead of a circle, a spiral line is described, with ellipses evolving on it, as is shown by pressing the paper against the axis for a longer time, the paper being covered with a thin layer of soot. The author tried to bring a top without the brass arm and ball in contact with a spiral line, constructed by a wire bent into a spiral line. The top then began rapidly to move along the spiral line, and, reaching its end, began to follow again the direc- tion of the spiral wire on its inner side, and so on. This spiral and periodical motion is similar to that of a pendulum on a pre- scribed or given trace; it is very like that of a cycloidal pendulum, where the motion must be performed on a cycloid. The disturbing force produces a pressure on the wire, and forces the axis of the a follow the direction of the spiral curve. he spiral may be replaced by a curve of any other description. On the Tangential Balance and a new Saccharometer. By Professor Cu. V. Zexcur. ProGreEss oF SCIENCE. On the Duty of the British Association with respect to the Distribution of its Funds. By Lieut.-Col. A. Srranen, F.R.S. The author begins by referring to the Royal Commission on Scientific Instruc- tion and the Advancement of Science, of which the Duke of Devonshire is Chair- man, the appointment of which was obtained by the British Association in 1870. Having been examined himself by the Commission, and having been in communi- cation with many of the witnesses who have appeared before it, he is able to say that the following fundamental points are receiving great attention, viz. :—(1) that the objects of scientific teaching and of scientific investigation are distinct, and require for their respective attainment distinct machinery ; (2) that the State is bound, in the interests of the community, to maintain Institutions, such as Labo- ratories and Observatories, for scientific research, apart from teaching; (3) that all State Scientific Institutions and action of every kind should be subject to the direction of a single Minister of State; and (4) that such Minister of State should have the assistance of a permanent paid Consultative Council, composed of eminent men of science. Of these measures he regards the two last (a Minister and Council) as by far the most important. The paper next proceeds to consider how the Association may further advance the great question of State Scientific Organization. The writer considers that one of the greatest obstacles in the way consists in the imperfect conception which statesmen have formed of the duties of the State with respect to science; and he believes that this is in a great measure due to indiscriminateness in private action and the distribution of private funds. Many great scientific problems have been taken up with the help of such means, only to be laid aside because those means have proved insufficient. The result is a confusion of thought as to what scientific objects should be carried out by the State, and what may properly devolve on private bodies and individuals. . In order to assist in clearing up this confusion, the author proposes that the _ Association should classify all applications for aid coming before them under two great heads—Public and Private; that they should grant pecuniary aid to the latter only ; that they should furnish the Government annually with a list of objects * 64 REPORT—1872. which they regard as Public, with such advice as to the best mode of attaining them as may seem necessary; and that before each annual meeting they should ascertain from the Government what progress has been made towards the attain- ment of those objects, publishing the result in their Proceedings. The author disclaims any wish to bring the Association into collision with the Government. He does not believe the above measures would have that effect; and he sees no other mode of bringing forcibly before the Government, in a practical form, those great wants of science which State resources alone can supply. He next proposes the following tests by which to distinguish Public Science for the purpose of classification:—(1) Continuity; (2) Probability of Expansion ; (3) Unremunerativeness to the individual cultivating it, combined with profit or advantage to the community generally; (4) Costliness. No body is better able to supply such tests with discretion than the British Association. The author then enumerates some typical examples of private aid injudiciously given to strictly public objects; viz. the Kew Observatory, Rainfall, Sewage, the Map of the Moon, and the Tides. After pointing out the effect in each of these cases, he then urges that the action now proposed will not chill individual enterprise, which is too fixed a sentiment in the English character to be capabie of eradication. He is convinced that ample use will be found for the limited income of the Association after eliminating purely public objects. He admits that such objects will perhaps at first be more or less neglected if abandoned by the Association ; but he considers that this inconvenience will be cheaply purchased by the dissemination of sounder views on State Science, to which it cannot fail to lead. CHEMISTRY. Address by J. HW. Guavstonz, Ph.D., F.RS., President of the Section. On of my fellow-students in the laboratory of the late Professor Graham began the study of Chemistry because he wanted to be a geologist, and he had read ia some Geological Catechism that, in order to be versed in that science, it was neces- sary, as a preliminary step, to gain a knowledge of Chemistry, Mineralogy, Zoo- logy, Botany, and I know not what besides. My friend became a chemist, and found that enough for the exercise of his faculties. Yet the catechism had truth on its side ; for so intertwined are the various branches of observational or experi- mental research, that a perfect understanding of one can only be obtained through an acquaintance with the whole cycle of knowledge. Yet, on the other hand, who can suryey the whole field even of modern Che- mistry? There was a time doubtless, in the recollection of the more venerable of my auditors, when it was not impossible to learn all that chemists had to teach ; but now that our “ Handbook” has grown so large that it would take a Briareus to carry it, and it requires a small army of abstractors to give the Chemical Society the substance of what is done abroad, we are compelled to become specialists in spite of ourselves. He who studies the general laws of Chemistry may well turn in despair from the ever-growing myriads of transformations among the compounds of carbon, We have agricultural, physiological, and technical chemists; one man builds up new substances, another new formule ; while some love the rarer metals, and others find their whole soul engrossed by the phenyl compounds. ‘How is this necessity of specialization to be reconciled with the necessity of general knowledge? By our forming a home for ourselves in some particular region, and becoming intimately conversant with every feature of the locality and their choicest associations, while at the same time we learn the general map of the country, so as to know the relative position and importance of our fayourite resort, and to be able (when we desire it) to make excursions elsewhere, To facilitate this is one of the great objects of the British Association. The TRANSACTIONS OF THE SECTIONS, 65 different Sections are like different countries ; and, leaving the insular seclusion of our special studies, we can pass from one to the other, and gain the advantages of foreign travel. From this Chair I must of course regard Chemistry as the centre of the universe, and in speaking of other Sections I must think of them only in their relation to ourselves, There is that rich and ancient country, Section A, which, according to the Annual Report, comprises several provinces, Mathematics, Astronomy, Optics, Heat, Electricity, and Meteorology. Mathematics and Astronomy.—It was when the idea of exact weights and mea-~ sures was projected into it that Alchemy was transmuted into Chemistry. As our science has become more refined in its methods its numerical laws have become more and more significant ; and it may safely be predicted that the more closely it is allied with general physics, the greater will be the mathematical knowledge demanded of its votary. But till lately the Chemist and the Astronomer seemed far asunder as the heavens and the earth, and none could have foretold that we should now be analyzing the atmospheres of the sun and stars, or throwing light on the chemical composition of planetary nebulw and the heads of comets. There is in this, too, as in other things, a reciprocal benefit ; for we are encouraged to hope that this celestial chemistry will reveal to us elements which have not yet been detected among the constituents of our globe. Light, Heat, and Electricity—How intimately are these associated with the chemical force, or rather how easily are these Protean forces transformed into one another! The rays of the sun coming upon our earth are like a chemist entering his laboratory : they start strange decompositions and combinations not only in the vegetable kingdom, but also among inorganic gases and salts; they are absorbed selectively by different bodies which they penetrate, or are refracted, dispersed, and olarized according to the chemical composition and structure of the substance. All this has been the subject recently of much scientific research ; and I need scarcely remind you of the beautiful art of photography as one of the results of ‘photo-chemistry, or of the benefits that have arisen from a study of circular polar- ization, indices of refraction, and especially spectrum-analysis. In regard to the latter, however, I would remark that while the optical examination of the rays emitted by luminous vapours has yielded most brilliant results, there is another kind of spectrum-analysis—that of the rays absorbed by various terrestrial gases, liquids, and solids—which has already borne valuable fruit, and which, as it is far more extensively applicable than the other, may perhaps play a still more impor- tant part in the Chemistry of the future. The dispersion of the rays of the spec- trum is certainly due to the chemical nature of the hody through which they pass; but this is as yet almost unbroken ground waiting for an explorer. As to heat, it has ever been the tool of the chemist; and it would be difficult to overestimate the significance of researches into the specific heat or the melting- and boiling- oints of elements and their compounds. ‘The laws of chemical combination have een elucidated lately by thermo-chemical researches ; it has been sought to esta- blish a connexion between the absorption or radiation of heat and the complexity of the chemical constitution of the active body; while the power of conducting heat, or of expanding under its influence, offers a promising field of inquiry. As to electrical science, one department of it (Galvanism) is strictly chemical ; the electrolytic cell does our work: and indeed we claim half the electric telegraph ; for while the needle may oscillate in Section A, the battery belongs to B. Last in Section A’comes Meteorology; and there are chemical questions con- cerning the constitution of the atmosphere, its changes, and the effect of its occa- sional constituents upon vegetable and animal life, which merit the deepest attention of the physiologist, philanthropist, and statesman, If we turn to Section C, there is an outlying province belonging to us—namely, Mineralogy, which lies on the frontiers of Geology. A_ vast and very promising region is the origin and mode of formation of different minerals; this has attracted some explorers during the past year; but in order to investigate it properly the geologist and the chemist must travel hand in hand. Geology, in demanding of us the analysis of earths and ores, rocks and precious stones, repays us by bringing to our knowledge many a rare element and strange combination, 66 REPORT—1872. When we pass from C to D (that is, from the crust of the globe to the organized beings that inhabit and adorn it) we are introduced into new regions of research. When organic chemistry was young, Cuvier said of it, “ Dans cette nouvelle magie, le chimiste n’a presque qu’a vouloir: tout peut se changer en tout; tout peut s’ex- traire de tout ;” and though we have now learnt much of the laws by which these magical transformations proceed, they far transcend the dreams of the French phi- losopher ; there is yet no visible limit to the multitude of products to be derived from the vegetable and animal world, and their changes seem to afford boundless scope for chemical ingenuity. The benefit here also is reciprocal; for the physio- logist enters by our aid into the wonderful laboratory of the living plant or animal, and learns to estimate the mode of action of different foods and medicines. There have lately been some good researches of this character. The difficulties are great ; but the results to be achieved are worthy of any effort. There may be little intercourse between us and the geographers in E; but we stand in no distant relationship with many of the subjects discussed in , Eco- nomic science embraces the chemical arts, from cookery upwards; such imperial questions as that of the national standards, or the patent laws, interest us greatly ; the yield of our corn-fields is increased through our knowledge of the constituents of soils and manures; and upon many of the chemical manufactures depend in no small degree the commerce and the wealth of Britain. In this most important branch of technical chemistry we need the skill of the mechanician ; and this introduces us to Section G. One of the questions of the day will illustrate the connexion between these varied departments of study. Sta- tistics prove that the consumption of coal is now advancing, not at the gradi pace which recent calculations allowed, but at a rapidly accelerating speed; and they make the householder anxious about rising prices, and the political economist about the duration of our coal-fields. It is well known that there is a great waste of fuel throughout the country, as the maximum of heat produced by the combustion is very far from being ever utilized; and it will be for the combined wisdom of the chemist, physicist, and mechanician to devise means for reducing this lavish ex- penditure, or to indicate other available sources of power, _ While this correlation of the natural sciences renders it desirable that the votary of one should have some general acquaintance with the rest, the correlation of all knowledge shows that no education can be complete which ignores the study of nature. A mind fed only on one particular kind of lore, however excellent that kind may be, must fail of proper nourishment. Iam not going to say a word against philological studies: I am too fond of them myself for that; and I could wish that the modern languages were taught more, and the classic languages were taught better, than they are at present. WhatIdo contend for is, that chemistry (or some cognate branch of science) should have an honoured place in the education of every English lady and gentleman. I say purposely “an honoured place ;” for at present where chemistry is introduced we too often find the idea latent which was expressed by one principal of a lady’s college, who told a friend of mine that he was to give the girls a course of pretty experiments, but that she did not expect him to teach them any thing ; and we know that when boys repeat chemical experiments at home it is looked upon as an amusement, a philosophical one no doubt, but rather objection- able, inasmuch as they spoil their mother’s towels and singe their own eyebrows. Of course some knowledge of chemistry is indispensable for a large number of our manufacturers, and for the medical profession, while it is extremely valuable to the farmer, the miner, and the engineer. It will also be readily granted that informa-. tion about the air we breathe, the water we drink, the food we live upon, the fuel we burn, and the various common objects we handle, must be of service to every man. But we are met by the advocates of the old system of education with the remark that the value of school-teaching does not depend so much upon the infor- mation given as upon the mental training. This I admit—though it seems to me that if the same training can be secured by two studies, the one of which (like the making of Latin verses) gives no information at all, and the other (like chemical analysis) imparts some useful knowledge, we should prefer the latter. But I hold that, asa means of educating the mental faculties, chemistry, faithfully taught, has TRANSACTIONS OF THE SECTIONS. 67 in many respects the advantage over literary studies. There issuperabundant scope for the exercise of the memory ; the powers of observation are developed by it to a wonderful degree; the reasoning powers may be well disciplined on the philosophy of chemical change, or the application of the laws of Dalton, Mitscherlich, and Avo- adro ; while the imagination may be cultivated by the attempt to form a conception of the ultimate particles of matter, with their affinities and atomicities, as they act and react upon one another under the control of the physical forces. And I might speak of higher considerations than mere intellectual culture ; for surely the works of the Allwise and Bountiful Creator are a more truthful and a purer subject of con- templation for the opening minds of youth, and more in accordance with Christian ideas, than are the crude notions of a past stage of civilization, and the ignorant and gross fancies of a defunct paganism. There is another requirement in education—the training of the mind to the dis~ covery and recognition of truth. For this purpose philological studies have no fit- ness; mathematical studies, though peculiarly adapted for it, apply only to cases | where demonstrative proof is possible ; but the study of physical science is remark- ably well fitted for teaching the proper methods of inquiry, and the strict relations between theory and fact. Now the historian, the politician, the mental philosopher, the theologian, or any one else who desires to influence the thoughts of his fellow men, should be in a position to distinguish between truth and error in his own de- permeents and his mind may be well disciplined for this by a study which is less iable to be disturbed by human passions, predilections, or wishes, and where the conclusions are more readily brought to the test of observation or experiment. Our Government insists on a certain standard of education for all who are-allowed to teach in our elementary schools. In those schools which receive no State aid it is only public opinion which can insist that the teacher shall be duly qualified him- self, Such bodies as the British Association form this public opinion, and will de- serve well of their country if they demand that these masters and mistresses shall know something of the material universe in which they move, and be able to im~ art to every child such scientific knowledge as shall afford him an interesting sub- ject for thought, give him useful information, and discipline his mental powers. Among the many services rendered by the monthly reports of the progress of chemistry which the Chemical Society publishes, and the British Association helps to pay for, there is one which is rather salutary than pleasant. They bring pro- minently before our notice the fact that in the race of original research we are being distanced by foreign chemists. I refer not to the quality of our work, about which opinions will probably differ, but to the quantity, which can be determined by very simple arithmetic. This is a matter of no small importance, not only for the honour of England, but still more for the advancement of science and the welfare of man. From the Physical Chair of this Association last year, a note of warning was uttered in the following words, after a reference to the sad fate of Newton’s successors who allowed mathematical science almost to die out of the country :—“If the successors of Davy and Faraday pause to ponder even on thei achievements, we shall soon be again in the same state of ignominious inferiority.” The President of the Chemical Society also, in the last Anniversary Address, drew attention to the diminished activity of Chemical discovery, and to the lamentable fewness of original papers communicated. He traces this chiefly to “the non- recognition of experimental research by our universities,’ and suggests that in the granting of science-degrees every candidate should be required, as in Germany, to prove his ability for original investigation. Concurring in this, T would remark that other causes have also been assigned, and other suggestions have been made. There is the small recognition of original research even by our learned Societies—at least such recognition as will come home to the understanding of the general public. It is true the fellowship of the Royal Society is awarded mainly for original discoveries, and there are two or three medals to be disposed of annually; but these distinctions fall to the lot of tae seniors in science, often men who are beyond the need of encouragement; and though they doubtless are serviceable as incentives, there is many a beginner in the honourable contest. of discovery who is too modest eyen to hope for the blue 68 REPORT—1872. ribbon of science. While the Victoria Cross is awarded to few, every soldier who has borne part in a victory expects his clasp; and so might every man who has won victories over the secrets of nature fairly look for some public recognition. It has been suggested, for instance, that the Royal Society, in addition to the E.RS., might institute an Associateship, with the letters A.R.S., designed exclusively for those younger men who have shown zeal and ability in original research, but whose discoveries have not been sufficient to entitle them already to the Fellowship. It is suggested, too, that the Chemical Society might give some medal, or diploma, or some similar distinction to those who contribute papers of sufficient merit. But beyond this is the non-recognition of scientific research by society in general, We can scarcely expect the average enlightened Englishman to be any thing but scared by a graphic formula, or a doubly sesquipedalian word containing two or three compound radicals; but he need not continue to talk of the four elements, or of acids being neutralized by sugar. But, indeed, the so-called educated classes in England are not only supremely ignorant of science ; they have scarcely yet arrived at the first stage of improvement—the knowledge of their own ignorance. Then, again, there is the excessive preference of practical inventions over theoretical dis- coveries—or rather, perhaps, the inability to appreciate any thing but tangible results, Thus a new aniline compound is nothing unless it will dye a pretty colour; if we speak of the discovery of a new metal by the spectroscope, they simply ask, What is it useful for? and the rigorous determination of an atomic weight has for them no meaning, or interest, or beauty. The general appreciation of science must be of gradual growth; yet there are wealthy men who know its value, and who might well become the endowers of research. There are, indeed, at present funds available for the purpose—such as the Government Grant, and the surplus funds of this Association; but the money is given simply to cover actual outlay; and this, though very useful, scarcely meets the case of those young philo- sophers who have no balance at their bankers, and yet must live. Will not some of these wealthy men endow experimental scholarships, or professorships, in con- nexion with our colleges, institutions, or learned societies? As an instance of the good that may be effected in this way, may be cited the Fullerian professorships; and as a very recent example, worthy of all honour, may be mentioned the purpose of Mr. J. B. Lawes, not only to continue his elaborate experiments at Rothamsted throughout his lifetime, but to place his laboratory and experimental fields in tfust, together with £100,000, so that investigations may be continued in the wider and more scientific questions which the progress of agriculture may suggest, The Government of our country, through the Science and Art Department, ren- ders good assistance to the teaching of science; and if the recommendations of the Royal Commission on Scientific Instruction and the Advancement of Science be adopted, the introduction of practical examinations for the obtaining of certificates for a superior grade of science-master will certainly foster a spirit of research. It has been generally held that the promotion of research is within the legitimate scope of government; and where, as in the case of Aristotle and Alexander, genius and industry have been sustained by princely munificence, the happiest results have ensued. Yet this question of Government aid is a delicate one: for genius, when put into swaddling clothes, is apt to be stifled by them; and were science to depend on political favour or imperial support, it would be a fatal calamity. Still I think it will be everywhere admitted that science might with propriety be subsidized from the public funds in cases where the results may be expected to confer a direct benefit upon the community, and where the inquiry, either from its expense, its tediousness, its uninteresting character, or the amount of cooperation required, is not likely to be carried out by voluntary effort. The astronomical work which is paid for by Government bears upon navigation, and answers both these requirements; and it is easy to conceive of inquiries in our own science that might equally deserve the assistance of the State. Some of these might also more ae repay the outlay, though perhaps the profit would not fall into next year’s udget. I believe that this diminution of original research, which we deplore, is partly due to a cause in which we rejoice—the recent extension of science-teaching. The professorships of chemistry are scarcely more numerous now than they were twenty TRANSACTIONS OF THE SECTIONS. 69 years ago, while the calls upon the professor’s time in conducting classes or looking over examination papers have greatly augmented. Thus some of the most capable men have been drawn away from the investigation of nature; and in order to afford them sufficient leisure for the purpose, means must be found to multiply the number of the professorships in our various colleges. While the rudiments of science are being infused into our primary education, now happily becoming national, while physical science is gradually gaining a footing in our secondary and our large public schools, and while it is winning for itself an honoured place at our universities, it is to be hoped that many new in- yestigators will arise, and that British chemists will not fall behind in the upward march .of discovery, but will continue hand in hand with their continental brethren thus to serve their own and future generations, Chemical Nomenclature. By Dr. A. Crum Brown. This communication does not contain a proposal of a new nomenclature or of a new system of nomenclature, but was intended as a contribution to that critical examination of chemical names which, it may be hoped, will lead to the develop- ment of a single language, capable of expressing clearly, completely, and shortly the actual relations of substances to one another, and any theoretical speculations which are, or may be, entertained by chemists. Three different kinds of names at present used are considered :—Ilst. Proper names, 7. e. names which, merely in virtue of a convention, represent particular sub- stances. 2nd. Names which indicate the composition of the substances represented. 3rd. Names which indicate the relation of the substances to others, and which may therefore be called functional names. In a functional nomenclature each substance will have more than one name, as it has more than one relation to other substances ; but no confusion need result from this, as each name will be used in its own place, when the relations implied in the name are treated of, On the Relative Power of Various Substances in preventing Putrefaction and the Development of Protoplasmic and Fungus Life. By Dr. F. Cracz- Catvert, F.R.S., F.CS., Se. To carry out this series of experiments, small test-tubes were thoroughly cleansed and heated to dull redness. Into each was placed 26 grammes of a solution of albumen containing one part of white of egg to four parts of pure distilled water, prepared as described in my paper on protoplasmic life. To this was added one thousandth, or ‘026 gramme, of each of the substances the action of which I desired to study. The reasons why I employed one part in a thousand are twofold :—first, the employment of larger proportions would, in some instances, have coagulated the albumen ; secondly, it would have increased the difficulty of determining the re- lative powers of the most efficacious antiseptics in preventing the development of the germs of putrefaction or decay, as the period of time required would have ex- tended over to twelve months. A drop was taken from each of the tubes, and exa- mined under a microscope having a magnifying-power of 800 diameters, This operation was repeated daily for thirty-nine days, and from time to time for eighty days. The tubes were kept ina room the temperature of which did not vary more than 3°, namely from 12°°5 C. to 15°5 C., during the time these experiments lasted. Tn order to appreciate the influence of the antiseptics used, 1 examined two solu- tions of pure albumen, one of which was kept in the laboratory, the other in the open air. a marked difference was observed in the result, the solution kept outside becoming impregnated with animal life in less than half the time required by the other, while as many vibrios were developed in six days in the solution outside, as were deve- loped in thirty days in the one in the laboratory. A summary of the results of the experiments is given in the following Table, in which the substances are grouped according to their chemical nature. 70 REPORT-~—~1872, Days required for | Days required for development of | due development Substances used. of putrid odours oe ee Fungi | Vibrios | in albumen kept at 15° C./at 15°C. at 26° C, 1. Standard Solutions. Albumen kept in laboratory for comparison...... 18 12 16 Albumen exposed outside laboratory .......,......- None | - 5 2. Acids. Rulphuvoustacid’ ¢. Heese sees geese case seecnes 21 11 45 Sulphunicticidr rantitec.drstescttesteerras. te eee 9 9 16 INIGIIC MAGIA: Shane eaecvedesnccdreattteen: ment te. seeees 10 10 16 PATSeMIONSIACICMisetase.ceaeteteetescackicsseeeias skeeete 18 22 None ACEbICIACIO): cs ave atelsie hn tie denim cates there Me scct sa Levee 9 30 None IBYUSSIC RCIA sts .t .crueecanteyenasuted ges iSoGtas dees tenes None 9 30 3. Alkalies. BU GM StH ABOUA dha ys sett SeR as cshtnadeeet ors: seis See 18 24 72 WHUBHC POLAR err e se dlrs ctecste ees tess cceutesks 16 26 85 Catshie iain Uni. SEA Wishes ectvasesccnatessegcexs b 20 24 26 (Canistie Aime rae. ans sssths saesccusiacesmsecchtmery sate te: None 13 14 4. Chlorine Compounds. Solution) of chlorine 6:.0:63. des .deisds sedarwescetbs cons 22 7 16 (CiloniGeolmodiura) ver 63.4% 1004dy eed vs ides cas dere 19 14 16 Bhloride of calotum | shy, szssectiweericen ters gather. 18 ir 11 Chioride\of aluminium’ sics.0s0sscssecsoetsveae.ccssi| 21 10 16 AOTC EOL ANG: frases: tate bays cpateens oe cates «Fe a ése 53 None 38 ESLEMIONIGE OL MELCUNY veer. 2. sabe sfaaessesss een .cn te 81 None None leachine-POywUGr sete seseecscavnsasccéssccsadedivnens&. 16 9 $) Chioratetofipotashies: ---.tsterteees ssbcieoceeeteneese r 19 17 38 5. Sulphur Compounds. : DM PUBEMOe trie! Sao ke eacer ects s.ostikeecceets es 19 9 14 Brotosulphate ofmeon Wyhs.csatetsssseestvenstsdeeeoe 16 1 16 Bisulphitelofdimess esveaewsetehesd. claw seat 18 11 16 Hyppst phiteyof BOG Bey arekes: sbeveasbere. theiwsclees 18 lL ll 6. Phosphates. PADS pHAte OL SOD)