VOLUME XXXIII. NUMBER 50Q. New Series. Volume VII. Part 12. DECEMBER, 1910. FOLSllEt) HV KiCHARU .A. PrOCTOK. 1*S1. Articles :— Plainly Worded. Subjects :— Exactly Described. ONE SHILLING NET. Entered at Stationers' Hall. NEW STUDENT'S MICROSCOPE Wnii rack coarse ami micro- meter sciew fine adjustments, 1 evepiece, 2 objectives— j" and i", double nosepiece, iris diaphragm, in oak case. £5 10 0. Catalogue post free. C. BAKER (^h't^:) 244. HIGH HOLBORN, LONDON. MAKERS Of NEW TKI-KX OHK^. OBjEcl GLA^^K^ KYE.LENSKS. PKI.-^MS, and other \sTROn6-M1£A1. APP-^^KATUS. Klc. BROADHURST, GLARKSON & Go. CHEMICAL WEATHER GLASS. A simple, cheap, and efficient instrument for indicating various CHANGES IN THE WEATHER. Post Free, 3s. 6d., with printed instructions. 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Physics Botany Zoology Geology Mathematics Classics English Literature ,, Language French German Geography History Logic 1 Economics ' British Constitution GLEW'S SGINTILLOSGOPE (Patent) t HOWS a mag^nificent display of scintillations, showers uf spatks, direct from the mineral Pitchblende, Radium, Polonium, Uranium, Thorium, or any radio-active substance, even an Incandescent tias Mantle contains sufficient Thorium to excite the very sensitive screen iji the Scintilloscope, which is far more sensitive than the Spinthariscope. The ScinLilloscope rivals the most delicate Electroscope as a detector of Alpha rays. The eye sees an inexhaustible shower of stars of white Hght, givin.^ a very realistic idea of the ceaseless activity of these marvellous substances which are producing the terrific bombardment causing this beautiful display. GLEW'S .SCINTILLOSCOPE, Superior Lens, with Extra-sensitlve Radium and Pitchblende Screens, giving brilliant effects, Complete, 7.s. 6d., Post free, U.K. Foreign Postage extra, weight 2 ounces. Pieces of Pitchblende mineral, ground flat and polished, with Sensitive Screen attached, for use in Scii.tilloscope or with any strong pocket magnifier, from 7s. Gd. each, according to size. F. HARRISON GLEW (Patenteki, 156, Clapham Road, London, S.W. — FLATTERS, MILBORNE — s AND McKEGHNIE, Ltd.. | Scientific Photograpliers & Microscopists Microscopic and Photomicrographic work in every branch of Nature and Commerce. Preparers of lextile Fibres and Fabrics, Paper and Paper-Pulps, ^^c. for Microscopic and Photomicrographic Analysis. Lantern and Microscopical Slides in every Branch of Natural Science a Speciality. All Requisites fur Mounting and fur Pund-Iife Work. CATALOGUES ON APPLICATION. *'THE MICROLOGIST,*' Is. 6d. Quarterly. 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Prof. RUDOLF EUCKEN (University of Jena) Christianity and the New Idealism. rUi oj inis sencs. H.\RPER & BROTHERS. 45 .A.lbem.\rle Street. LONDO.N. W. SCIENCE IN MODERN LIFE. Prof. J. R. Ainsv\^orth Davis, M.A., IVilh the co-operation of the following el-jen tintnent Spi,:ialiits : \. C. D. CROVIMELIX. B.A., F.R,.\.S.. of the Royal Observatory, Ureeiiwich. ' I. T. lONKS. M.A.. F.C.S., of H.M. Ceological Survey. J. P. .MILL1N(JT0X, .M.A., B.Sc, formerly ScholaV of Christ's College, C"anihridge. ]. H. SHAXBV, B.Sc, Lecturer in Phy.sics in University College, Cardiff. H. J. FLEURE, D..Sc., Lecturer in Cieo]og\- and Geography in University ("ollege. .Vberi-stwvth. H. SPENCER H.\RRlSON. D.Sc. formerly Lecturer in Zoolow in University College, Cardiff. ' ' I. M. F. DRU-MMOXI), il.A., Lecturer in Botany in the .\nmtrong College, Xewcaslle-upon- Tvne. J. TR.\yiS JEX'KIXS, D.Sc., Ph.D., Scientific Superintendent of the Lancashire and Western Sea-Fi.sheries Committee. .lAMES WILSOX, il.A., B.Sc, Professor of .\griculture in the Roj-al College of Science. Dublin. BEXJAMIN IIOORE, M.A., D.Sc, Professor of Bio-Chemistry in the University of Liverptwl. ;. W. FRENCH. P..S.. K,lit.,r ,.f ■■ M,,.l,.r., P,.u,-r.i;r.,<.r,,l,.r« ■ ."tc SCOPE OF THE WORK. The work sums up in an accurate and yet a readahle fashion the present state of knowledge in Science — The Nature and Cause of Sun Spots ; Origin of the Solar System ; Origin of Mountains : The Ice .Age ; The Nature of \'olcanoes and Earthquakes ; The Nature of Matter; The Kontgen Rays and Radiography; The I'ropetties of Radium ; Electrons and their Work ; The Physics of Soap Bubbles ; The Spectroscope .and Spectra ; Dispersal of Seeds and Fruits ; The Eggs of Deep-Sea Fish ; Serum Treatment of Diseases ; Progress of Sanitary Science ; The Importance of Heredit)' ; The Theory of Natural Selection ; The Finsen Light and X-Rays ; The Cradle of the Human Race; The Races of Mankind; The Submarine ; I'lant Associations ; Strange Extinct Animals ; Evolution ■ if tlie Animal Kingdom; The Progress of Scientific Agriculture; The Village Community ; The Life History of the Eel; The Stone. Bionze. and Iron Ages ; .Aeroplanes and Dirigible Balloons. 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Price 2 - post free from the Pnblishers. BROWN & SON, 51, Victoria Street, Douglas. Elementary Photo = Micrography. .SLCO.NU LUITION;. FnUirKcd, Kevised and hroiij;lit ur-t"-Uatt. By WALTER BAGSH.WV. Forty-five Ulustr.iiions. Cloth bound 2 6 net. Post free 2 9. XA TL'KE says :— " Simplicity and the absence of any recommendation to u^e complex appar.-Hus is the keynote of the entire book." ILIFFE & SON. Ltd.. 20, Tutior Street. London. E.C. WHAT BECOMES OF THE SUNLIGHT AND HEAT ABSORBED BY THE EARTH P A Booklet explaining tlie Theory of the Continuous Cycle of Operations of the Energy of the Solar Syste'ni, and setting forth the strong evidence in support of it. incidentally describing the Cause of Gravitation. The .Author is unable to find any established scientific fact challenging the theory, and if any .Astronomer. Physicist. Geologist, or Meteorologist, knows any such fact, the Author will be very grateful for the information. 8»o. 1 -, post free 1/1. J. D. ROOTS & Co., 231. Strand, London. KNOWLEDGE. December. 1910. THE SANITAS ELECTRICAL Co., Ltd. Works : Specialists in X-Ray and all Electro-Medical Apparatus, 61, NEW CAVENDISH ST., LONDON, W. ^. ^ .0. bent.nck mews. w. A NEW RANGE OF - ~ HEAVY DISCHARGE COILS FOR RAPID RADIOGRAPHY, i&c CilVINU 60 AllLLIAMPERKS ACROSS AN 8 INCH AIR GAP. Woii'id on the latest approved Multiple- section principle. Highest efficiency and finish coinI)ined with long life. Not a single coil supplied by us during a period of nine years to date has broken down or in any way needed repair. These coils will increase the efficiency of any outfit with any Interrupter, but are specially built to suit our famous "Sana-v" Interrupter, in conjunction with which they represent the highest attainment in X-ray technique. Absolutely steady It'sht of intense brilliancy for screen examinations. Times of exposures for radiography reduced to the absolute minimum. Perfect control and regulation for Therapeutic treatment. 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Only a Revolving Segmented Disc, rotated by the centrifugal ly-d riven ring of mercury. N/WWVXi^ o,oe?^ tfi-c. :^j:v:^iSgS'JJiJtEWa-itfM The id' .1 .'.!■■ i ■ I ititerruption. Kach iiiterrujition absolutely uniform. I ireat rapidity as denoterl by the time in illustration. Taken l>v the Physical Laboratory. Write for Catalogues and a new book of Testimonials and Reports and Opinions of leading X ray and Scientific workers. HARPER S XMAS NUMBER NOW READY. SEVEN COMPLETE STORIES ot varied type by Margaret Deland, Henry V'an Dyke, Carolyn Wells, Amelie Rives, &c. SIXTY ILLUSTRATIONS jn colour and monochrome by Frank Craig, Elizabeth Shippen Green, F. Walter Taylor, Peter Newell, Ac. PAPERS ON ART, LITERATURE, &c., by W". D. Howells, Richard Le dallienne, Christian Brinton, Norman Duncan, &c. JAMES SWIFT & SON, OPTICAL & SCIENTIFIC INSTRUMENT MANUFACTURERS, all Satntilic IKpai tii:cnU ol J/.M. (,.',-/. Gold Medals Awarded for Optical Excellence. IMPROVED UNIVERSITY MICROSCOPE, W nil 1 111. anil \ in. or i in I )li- jeclives, one Ocular anfl Iii^ Diaphragm, in Cabinet. £9 10 0. I'iiiocular arrangement, e.vtra. £2 12s. Patent Mechanical Stage, £2 10s. An Ideal Instrument for Professional or Amateur. UNIVERSITY OPTICAL WORKS 81, TOTTENHAM COURT RO.. LONDON. CONTENTS. Sixty Years of Chemical Progress. By E. S. Grcic. M.A. 463 International Union for Cooperation in Solar Research. Br W. ShacklctoiK F.R.A.S., A.R.C.S. 465 Opinions Rendered hv the International Commis- sion ON /Zoological Nomenclature. July, 1910. By the Rci: Thomas R. R. Stehhing. M.A.. F.R.S. 46S The Spectroheliograph. By FraiiK- C. Dennett 470 Treasures of the Snow. By Jean M. Tlioinpson 472 The Face of the Sky for December. By \V. Shackleton. F.R.A.S.. A.R.C.S. 474 Solar Disturbances During October. 1910. By Frank C. Dennett 475 Correspondence ... ... ... 476 Queries and Answers 477 A Zoological Gathering ... ... ... ... 478 Notes. — .\stronomy. By G. F. 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WAVELENGTH SPECTROSCOPES. QUARTZ SPECTROGRAPHS. .\\v\ othei High-clas.s Instruments. I litjh (iiKilitv work alone undertaken: 1.1 all work cl(, 75a, CAMDEN ROAD, LONDON, N.W. I .-Ic-r.iiMs : ■■ SfMM:lLlT\, LmM.un." Telr|.liOrH- : XORTH lOSy. AWARDED GRAND PRIZE, BRUSSELS EXHIBITION, ipio. Illuslrateii Lists of Spectroscopes ,iiid Spectioscopic App.o-.itns of all kinds gratis on reiiuest. Knowledge. With which is incorporated Hardwicke's Science Gossip, and the Illustrated Scientific News. A Monthly Record of Science. Conducted bv Wilfred Mark Webb, F.L.S., and E. S. Grew, M..\. DECEMBER, 1910. SIXTY YEARS OF CHEMICAL PROGRESS. Bv E. S. GREW. M.A. Last month (Friday, November 11th), the Chemical Society held for the third time in its history a Jubilee Banquet, entertaining thereat, as guests of the evening. Professor ^^'iHiam Odling, F.R.S., Sir ^^'ilIiam Crookes. O.M.. F.R.S.. Dr. Hugo Miiller. F.R.S.. and Dr. .A.. G. \ernon Harcourt, F.R.S. The fifth guest, Sir Henr\- Roscoe, F.R.S., who, Hke the other four, has been a President of the Society and a member of it for fifty years, was, unfortunately, unable to be present. It is nearly seventv years since the Chemical Society was founded (on March 30th, 1841), and its two previous Jubilee Banquets commemo- rated its foundation and the granting of its Royal Charter of Incorporation bv Queen ^'ictoria. on Novem- ber 2nd, 1848. At the ^ir William Crookes first of these banquets. Dr. \\". J. Russell. F.R.S., who died a vear ago (November 12th, 1909), presided ; and among the speakers on that occasion were the late Marquis of Salisbury and the late Lord Playfair. At the second Jubilee Banquet no fewer than si.\ of its past Presidents who had been members of the Society for fifty years were the guests of the evening. Their names were Professor J. H. Gilbert (of the Rothamsted experi- ments). Sir Edward Frankland, Professor William Odling. Professor A. W. Williamson. Sir Frederick Abel, and Dr. J. Hall Gladstone. Lord Playfair was to have been the re- maining guest — the first in point of seniority: but he died before the Banquet took place, and it was post- poned from June to Novem- ber in consequence. At the time of his death, in June, 4898, he was the last sur- vivor of the seventy-seven chemists who had joined the Society as original members on its foundation. Of the other past Presi- dents at that banquet, all now are dead, except Professor in his' Laboratory-. Odling. whose perennial vouth of spirit, may, we hope, preserve him to science and education for rears to come. Professor Odling was born in 1829", and is still Waynflete Professor of Chemistry at Oxford University-. He has made his mark as a teacher and as a philosophic chemist of the highest rank; and he is known throughout 463 464 KNOWLEDGE. December. 1910. the world as a chemi.st who has alwaxs been in the highest degree accessible to new ideas. No one has done more than he to champion the modern development of Chemical Theor\- : and the words which Sir James Dewar spoke of him twelve years ago are as true to-dav. "Ever_vone must admit,"" said Sir James Dewar. "the debt of gratitude we owe him for his iconoclastic labours in clearing out old and vague notions, and for the courageous manner in w hich he has supported the newer ideas of his time."' Sir Henry Roscoe"s fame as a teacher of chemistry is world-wide. His tenure of the Professorship of Chemistry at Owens College, Manchester, did more than anything else to ele\'ate that institution, and the University of Manchester by which it was succeeded, to its present position as the foremost School of Chemistry in Great Britain. Sir Henr\- has alwaxs laboured to establish what we may jierhaps describe as the official recognition of Chemistr\- : his bene- factions to Chemical Institutions — and not least to the Chemical Society and its Librarv — have been great and numerous. His work on the relation of Chemistry to Public Health, and his researches on the .Atomic Weight of Carbon, on \'anadium, and in Spectrum analysis have given him a place of the highest rank among chemists. Sir \\'illiam Crookes. O.M., Foreign Secretar\- of the Koyal Society, is a chemist whose work has extended tmm the domains of pure chemistr\- and industrial chemistry to that of physical chemistrw and has been of the greatest significance to physics and the fundamental physical conceptions of matter. It is sufficient to enumerate some of his investigations to indicate the range of his work. His discover\- of Thallium, in 1861, was one of the first-fruits of the then new science, spectrum anah'sis: his researches in the rare earths and the genesis of the elements have followed in logical sequence. Phxsics will always commemorate him for the "radiant matter,'" the " fourth state of matter," to which he was the first to give these cognomens ; and his " Radiometer " and " Spinthariscope." toys though they have been said to be, have none the less furnished material illustrations of the fundamental relations of matter and energv. Dr. Hugo Muller was the only one of the five guests who was not born a Londoner. He was born at Tirschenreuth in Bavaria, and he is one of several great Anglo-German chemists whose dis- coveries have been at the service of his adopted country. His early researches on the replacement of hydrogen and chlorine are the basis of much of the modern synthetic methods. His work on cellulose and on other subjects produced bv plants is of the highest importance. It has been said of him that what he does not know regarding the chemistry of ])aper is not worth knowing. He is even better known as a mineralogist than as a chemist, and some of his modes of extracting, from minerals, products \aluable in medicine are models of simjjlicit}- and accurac}- — as in the extraction ol litliiuni s dts from triplnlline. Dr. A. G. \'ernoii Harcourt is well known to Oxford men as one of the most enthusiastic teachers of Chemistry who ever laboured in that Universit\', and his researches on the rate of chemical change marked an epoch in ])hilosophical chemistrv. In more utilitarian fields, his publications on Chemistry, on Education, on Coal Gas, and Photometr\-, on Chloroform and its anah'sis, and its safe administra- tion as an anaesthetic have added to the fame of the Oxford School of Chemistrw as well as to his individual reputation. l)Ut that, perhaps, which is most imi)ressi\'e and conspicuous at a banquet of this kind is less indixidual achievement than the conception of the accumulated knowledge during the period w hich has been covered by the work of the chemists. In the sixt\' vears of their joint exjierience the faces of chemical theory and of chemical practice have alike been changed. It would be impossible in the space of one article to summarise with e\en approximate adequacy the features of chemical progress in sixtx' vears: but a very brief sketch of the change has been tentatively furnished bv Professor Odling himself. The greatest change of all has been in the advance of the theories of chemical constitution. Following on the acce[ited theories of Dalton came the doubts awakened b\- newer in\'estigations. and the assumptions which had to be made to reconcile theor\' with iinestigations. Laurent and Gerhardt working at the relative reacting unit weights of bodies ; Liebig w ith his compound radicles : the work of Dumas in chlorine solutions : Graham's researches on the pohacidic acids : Williamson on the compound ethers : \^'urtz and Hoffman on the compound ammonias : and the extension by Caniz- zaro of the work of Wurt/. were all steps in the stairwav which led to a clearer comprehension of the units of chemical constitutions and their types. Thereafter the air w as further cleared by Frankland's pol\-combinations and Gerhardt's tj-pes of dissocia- tion. The re\-ision of the atomic w eights led through Newland to Mendeleef — and to Mendeleef's concep- tion of the table of the elements. Lyon Playfair and Kekule carried the work on till Lebel and Van t' Hoff furmulated the doctrines of isomerism and rotating polymerisation. . . . Each of these men is a link in a great chain ; but the work they do is never-ending, and on it can never be written the word "Finis." That is true ot an\ chemical researches: yet. if we were to seek in a review of chemical progress over sixtv vears for positi\e features they would be easil}' found in the work done by those who — from Berthelot to Emil Fischer — ha\-e pursued the syn- thesis of organic bodies: and in the great branches of knowledge which have sprung from the parent growth of chemical dissociation — such as the fundamental doctrines of Ampere and Avogadro : the theory of solutions; electroh'sis; and the state of matter at high temperatures with its corollar\' of spectrum analysis. INTERNATIONAL UNION FOR COOPERATION IN SOLAR RESEARCH. Hv w. shackli:to.\. f.k.a.s.. a.k.c.s. Thk fourth Conference of the International Union for Cooperation in Solar Research was held at the Solar Observator}- of the Carnegie Institution, Mount Wilson, California, from Aug. 30th to Sept. 3rd, and several representa- tives from this countr\- were present. Previous conferences have been held at St. Louis, Oxford and Paris. The meetings are now triennial, and the next is arranged to take place in Germany. Great Britain was represented bv Rev. A. L. Cortie, S.J., Professor F. W. Dyson, Professor A. Fowler, Major E. H. Hills, Sir Joseph Larmor. Professor H. F. Newall. Professor A. Schuster and Professor H. H. Turner. Other distinguished as- tronomers and ph\'sicists from Germany, Russia, France, Austria, Holland, Italy, Switzerland and Sweden were also present, together with a large gathering of the American astronomers. The proceedings of the conference consisted of the discussion of the re- l)orts of the various com- mittees appointed at the previous conference, at Meudon, in 1907, to investigate solar radiation, sun spots, solar rotation and standards of wave-length. The International Eclipse Committee also met. and a new committee was appointed to consider the important subject of the classification of stellar spectra, as, obviously, solar research can be materially assisted by a study of the manv stars with svhich it is so intimately related spectroscopicalh-. These proceedings, when published, will form the third volume of the "Transactions of the Inter- national Union for Cooperation in Solar Research."" Hn route to Mount \\'ilson Solar Observatorv manv of the astronomers took part in the meeting of the .\stronomical and Astrophysical Society of America. This Societ\' meets once a vear, as American astron- omers are scattered over the whole of the continent, and cannot readih' meet at shorter intervals, the Tower Telescope, Solar Observatory, California, selected place of meeting of the Society this year being Harvard College. Here several papers on Hallev"s comet were read by Professor Barnard and others, together with a [laper on the results of the Societv"s expedition to "^ Hawaii to observe the comet. These were supplemented by a paper from Professor Fowler, on the "Spectroscopic Features of the Head and Tail of Comets."" This paper elicited some discussion and received warm approbation. Another interesting paj)er was read by Mr. Joel Stebbins on "The Measurement of the light of Stars with a Selenium Photometer, and its application to the varia- tions of Algol."" He showed that Algol has a second minimum, and that the light curve between the two minima is not flat. The results derived from this research indicate that the dark companion to Algol is not black light than the Sun The obsers'atories at Harvard College, under but gives off more Mount Wilson, the Directorate of Professor Pickering were thrown open to inspection : it may be mentioned that the 5 -foot reflector formerl\- belonging to the late Dr. Common forms a part of the equipment of this observator)-. During the week preceding tlie Conference many of the part}- crossing from East to West visited the Flagstaff Observatory, Arizona, where Professor Lowell personally welcomed the astronomers, and showed man\- of his photographs and drawings of Mars, On arrival at Pasadena the physical laboratory, workshops and computing establishment were inspected, the astronomers then gradually made their wa\- up tlie mountain trail to the summit of Mount Wilson (altitude 5,886 feet), where the observing portion of the observatory is situated. Bevond extending a heartv welcome to the 465 466 KNOWLEDGE. December, 1910. numerous Professor delegates Hale, July 17, 1905, 17" 56'". Low- Level Cal- cium Flocculi Slit Set on Hi (X3965) Sun's Diameter =0.28 meter. r; TIk' report of the given hy Professor Schustt Professor Kayser pre- sented the report of the Committee of wave lengths, suggesting the adoption of three hun- dred and seventy - one standard wave lengths, mosth' of tile iron spec- trum. Mr. Abbott jjresentetl the report on the meas- urement of Solar radia- tion. The most probable value of the Solar Con- stant of radiation appears to be about 1'92 calories per square cm. per minute. Professor Fowler pre- sented the report of the committee of Sun-spot observations, one result of which is, that the spot spectrum is found to be as constant as the Fraun- hofer spectrum itself. Professor Newall spoke ol the possibility of using plane gratings for measuring the tertiar\' standards, whilst Professor and giving a short ^address, unfortunately, was unable, on account of illness, to take an active part in the meet- ings. In his address he spoke of the use I if the Conferences and of their stim- ulation to research: also on the needs of tertiary standards. and the preparation of a sjjectrum map on a large sc;de. He also spoke of the new tower tele- ■-cope and com- bined spectrograph .iiul spectrohelio- L;raph, illustrated m this article. Tlie sessions of the Conference then formalh' be- gan, and the reports of the \- a r i o u s committees were received. Executive Committee was 20, 1905. 5" 18"'. High-Le Calcium Flocculi Slit set on Ha Sun's Diameter = 0.28 meter. ^ f ■ ■«•■#-? . '5'. -:£\^-' wave lengt I'abrN" said that for short portions of the spectrum plane gratings may be even better than concave Mr. Adams gave the report on the determination of Solar Rotation by the displacement of lines, and spoke of the use of the plane grating in measur- ing Solar rotation at Mount Wilson. Professor Frost presented the re- port of the Com- mittee on the spec- troheliograph. It was decided that daily photographs of Calcium flocculi should be con- tinued. In addition to the meetings, the astronomers made a detailed inspec- tion of the instru- ments used in the advancement of astrononi}', particular interest being taken in the new tower telescope, 180-feet high including dome, and • . - -..-, ^ ..;- its 80-foot deep pit for ; the new combined spec- -. ; trograph and spectro- ' iieliograph. The tower is surmounted by a dome containing a coelostat and necessar\' mirrors to project the beam of light on to the 12-inch object glass, situated near the summit of the tower, which focusses the image of the sun on the slit of the spectrograph in the linuse at the foot, the -tiisitive parts of the spectrograph being situated in the under- ground pit to maintain constant temperature. The tower itself is realK" two towers, one within the other, having al)out i-inches clearance between them, so that the inner one is shielded b\- the outer from the direct ra\'s of the Sun, and also from the force insulated portion which (objective. -^ "§??« 4. Hsdro^cu (Ha) I'locculi photuj^raplu il Snow Telescope and 5-ft. Spectroheliograph. of the carries wind. It is the coelostat this and DECE^rBER, 1910. KNOWLEDGE. 467 When the new spectroheHograph is completely installed, there is every reason to expect that Professor Hale will surpass the results he has already obtained. Figures 2 and 3 show some of the Calcium Flocculi photographed with the Snow Telescope and spectroheliograph. Further, the n e n\' 5-foot reflecting tele- scope constructed b}- Professor Ritchey was thrown open for the dele- gates to make observa- tions. It was estimated that stars down to the 17^ magnitude could be visually observed, which is half a magnitude fainter than hitherto approximately obtained, whilst photographs show stars down to the 21st magnitude. Saturn formed the sub- ject of much scrutiny, and the definition, using a magnification of 600. was superb. S e \' e r a 1 important new features on the planet were dis- covered, whilst other de- tails imperfectK' estab- lished were confirmed and full\- observed. Other objectsof interest were viewed, such as the Cluster in Hercules, and it is the good fortune of few astronomers to observe FlGC .A. 5 -foot Telescop< such objects with a magnifying power of 600, giving crisp definition and an aperture of five feet. The 5-foot telescope can be arranged for visual work with an equivalent focal length of 100-feet. On the return journey arrangements had been made for the delegates to visit the \arious observa- tories of Lick, Univer- sit\- of California at Iierkeley, San Francisco. Verkes, .Allegheny, and Washington. Each of these observatories placed their instruments at the disposal of the parties. With such generosity and among such a series of powerful instruments it would be invidious to point to anv one in par- ticular, bnt a striking feature of the observa- tions made with the 40- inch telescope of the Yerkes Observaton,' was the ease with which one could see the faintest planetarv nebula and the t\\o faint stars in the King Nebula in Lyra. One cannot help feel- ing that the science of astronomy is very much alive in .\merica. and that such meetings not onlv stimulate the spirit of scientific research, but tend to national goodwill. kh 0. ' at .Mount Wilson NoTi:. — In connection with the article printed on Professor Hale, who is now in England, has kindh Pages 433 -5 in ■" Knowledge " for last month, written the note which is jTrinted below. The article on the Mount Wilson Solar Observatory in tlie November number of "Knowledge" contains so many errors and obscure statements that it is impossible to correct them all. The account of the Snow telescope is badly confused. The concavity of the third mirror is not " very great," as stated, but very slight, as the radius of curvature is sixty feet. The light of the Sun, or other object under observation, does not '" fall through " the two plane mirrors, but is reflected from their silvered front surfaces. Nor do the observers " stand round " the third mirror, but near the focal plane, sixty feet from its face. " Pasadona " should be ■'Pasadena," " Ellerton " should be "' Ellerman," and '"Carnegie Institute" should be "Carnegie Institution" (the Carnegie Institute is a combined library and museum in Pittsburgh), Mr, Adams is second in charge, and serves as Acting Director in the absence of the Director. Other members of the staff, not mentioned in the article, are Professor Kapteyn, Research .Associate : Professor Scares, Superintendent of the Computing Division ; Dr. King, Superintendent of the Physical Laboratory ; Professor Ritchey, observer with the sixty-inch reflector ; Dr. St, John, solar observer ; Mr, Babcock and Dr. Foth, assistants, Mr. Backus has not been connected with the Obser\'ator>' for several years. The description of photographs of the calcium lines (p. 435, top of second column I is hopelessly confused, and the subsequent remark, which seems to imply tha't " they can take a photograph twice a day" in the physical laboratory, is equally so. The meaning of "twenty-six acres below" (near the foot of the page) is a mystery. The sentence "The buildings are permanent, but others are still to come for the great five-inch reflecting telescope " is diflficult to understand. Apparently it refers to the sixty-inch reflecting telescope, which has been in regular use in its dome since December, 190S, Possibly the author's visit to Mount Wilson was made several years ago, as he does not mention the sixty-foot tower telescope, erected in 1907, or the recently completed one hundred and fifty foot tower telescope. The final sentence of the article is also misleading. The Observatory did recei\e an appropriation of ^150,000 from the Carnegie Institution for expenditure in one year, but less than one-third of this was used for maintenance, the balance being devoted to the purchase, construction and erection of buildings and instruments. OPINIONS RENDERED BY THE INTERNATIONAL COMMISSION ON ZOOLOGICAL NOMENCLATURE, JULY, igio Bv THE Ri:\'. THOMAS R. K. STEHIUXC., M.A.. F.R.S. '■ I WENT by the field of the slothful, ami 1>\ tlie vineyard of the man void of understanding; ; and. lo, it was all grown over with thorns, and nettles had covered the face thereof." So spoke one of old, reputed to be the greatest naturalist of his age, supremeK' con\'ersant alike with the \'egetable and animal kingdoms of nature. Well, here, nearly three thousand years later. \\e ha\e the field of the industrious and the vine\ard of distinguished ;?o6logists, and. lo. it is all grown over with thorns. and nettles cover the face thereof. What these thorns and nettles are I shall seek to e.\i)lain, with ready recognition that to a large extent they may be due much more to the soil which has to be culti\'ated than to an\- fault of the cultivators. To begin with, we are at an ejioch when the unitx' that underlies the diversitv of natural phenomena is making itself more and more appreciated. Yet botanists and zoologists have chosen this ver\- period for settling how to name the objects of their respective sciences by separate sets of rules. Though alike accepting the introduction b\' Linnaeus of the binominal or binomial system as a starting jioint for the scientific nomenclature of living organisms, the\' have nevertheless chosen each a different date for that starting point. E\-entuall\' the zoologists, who have already harked back from A.D. 1767 to 1758. will perhaps do themselves the credit of joining the botanists in dating the beginning of the world (of Natural History) from 1751. In the ne.xt place, we have to consider the main purpose of the jiresent International Commission. A brief history of it is given in the pamphlet under review.* Its appointment dates from 1895, at the Third International Zoological Congress. The following Congress, the only one that has been held in England, was a brilliant gathering at Cambridge, in 1898. On that opi^ortune occasion all public discussion of the question in hand was deliberately quashed. The commissioners, five in number, were authorised privateh- to coopt ten others. No fault can be found with the standard of abilit\- in the men chosen to serve. Rather, in some cases, one might feel that a razor was being used to cut through a whetstone. B}- the arrangement that at each triennial Congress a group of fivt' members should retire, the term of office for each group becomes normall}' nine years, sufficient, one would think, to secure continuit\' without stagnation in the methods and resolves of the Commission. Ikit this salutary rule is at once stultified b\- a rider permitting the immediate re-election of retiring members. .Xjiart, however, from any faults in its constitution, the purpose of the Commission is on the face of it highh- laudable, namelw to secure uniformit\' among zoologists all o\er the workl in the technical designation of the objects they study. How, then, is this purpose being pursued, and w ith what chances of success ? Confessedly, '" the Commission has no legislative power," nor, for that matter, has the Congress which appoints it. The work nuist be done bv persuasion and consent. Yet. so far as appears, the numerous societies in Great Britain and Ireland more especialh' con- cerned with zoology have not been in an\- way approached for an expression of their wishes or opinions. An\- society, or any private individual, ma\' submit to the Commission views or problems, but no judgment upon them can be hoped for unless they have been sent in at least one year prior to the meeting of the next Congress; thus, perhaps, leaving an unhappy enquirer with an interval of three years and eleven months or more betw een his question and the tortoise-like response. When these dilatory tactics are understood, it is probable that writers will act on their own advice with more satisfactory promptness. If a member of the Commission were himself bringing out a treatise, he would assuredly tr\' to bring it u[) to date by critical citation of the latest arguments, whether for or against his own point of view. Wh)' should the Commission pursue a different policy ? It is evident that they do, for in Januar\-, 1903, the Zoologisclter Anzeiger published a long article by Dr. von Linstow. which in May, 1907, was translated in the Annals and Magazine of Natural History, under the heading " Modern Helminthological Nomenclature," while the Com- mission in its recently published opinions does not condescend to argue with Dr. von Linstow, or to notice him at all. But to ignore is not to conciliate, much less to convince. Without trespassing on the science of the Helminthologists, which has thus been left in the lurch, I shall venture to challenge certain opinions here rendered in a branch of study with which I am more familiar. Opinion 1 1 deals with " The Designation of Genotypes by Latreille. 1810." The case is stated h\ Miss M. J. Rathlum. the eminent Piililislu'd li\' I hr SmilliMiiiiuii Instilutimi. \\'ahliini;toii 46« December. 1910. KNOWLEDGE. 469 American carcinologist. with whom I argued the matter out in Xafiiral Science. \'ol. XII., No. 74. April, 1898. Now Dr. Stiles remarks, " The Secretary has examined Latreille (1810> in search of evidence in support of the contention which Miss Rathbun states has been advanced, but he has failed to find it."' The failure is remarkably like Nelson's failure to see a signal \\ ith the telescope applied to his blind eve. Had Dr. Stiles read my article, to which his attention was called by his fellow- commissioner, Dr. Hoyle, he could scarcely have persuaded twelve of his colleagues to concur in an opinion based on an irrelevant failure. I^atreille's own writings show that he used the French word '■ type "" as an equivalent of the French word " exemple," and that he could have had no intention bv the list in his manual of 1810 to set up what are now understood as typical standards for genera. It mav be urged that in this subject matter we have nothing to do with an author's intention, but are onlv concerned with what he actually published. Those who have followed this controversy will be aware that the authority of Latreille's manual was invoked in order to annex the genus Aatactis for the freshwater crayfish instead of the marine lobster. My contention has all along been that the genus Asfaciis, at one time ver\' comprehensive, was first subdivided by our countryman. Dr. William Elford Leach, who allotted 4 sf£TC!