w3 •r i 'afer.yy-Tr^'.-^-^- -«■ *c e'^,/ ,^i/ ^ ^u. a ■^■&£'/'u< fimi- a, ^u?£ofyl;:i/iAy^ -London. pit bl'.sh^d et ■ 1'la.ctniLla NATURE A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE VOLUME XVIII. MAY 1878 to OCTOBER 1878 " To the solid ground 0/ Nature trusts the mind which builds for aye" — ^^^'^ORDSWORTH MACMILLAN AND CO. 1878 x^^ \ tONDON : B. CLAY, SCMS, AND TAVLOR, PRIKTER?, BREAD STREET HILL, QUEEN VICTORIA STREET ,^« .OD «t KAture, AVcK 21, 1S78] INDEX Abbay (Rev. R.). Physical Science for Artist?, 329 Abercromby (Hon. Ralph), the Reduction of Meteorological Observations, 83 Aberdeenshire Agricultural Association, 640 Abney (Capt. W. de \V„ F.R.S.), on Photographing the least Refrangible End of the Spectrum, 163 ; Physics in Photo- graphy, 489, 52S, 543 Abyssinian Tube- Well, Improvement on, 105 Academic Liberty in German Universities, Prof. Ilelmholt/, F.R.S,, 50, 78 Acid?, Dilute, the Action of, on some Amalgam Surface?, Robert Sabine, 441 Acoustical Phenomena, Lord Rayleigh, F.R.S. , on the Explana- tion of, 319 Adams (Prof. A. Leith), Extinct and Recent Irish Mammals, 141 Adelaide Botanic Garden, Catalogue of, 344 Adulteration of Food, Laboratory for Detecting, m Pan?, 393 .4iolotropy, Sir William Thomson, F.R.S., on, 180 Aeronautical Society, $76 Aeronautics, see Balloons Afghan and Indian Frontiers, Stanford's Map of, 647 Africa : D'Anvers' Heroes of South African Discovery, 1 1 ; Lake Nyassa, 20 ; Exploration of, 68 ; Exploration of the Gabun and Ogovai, 95, 180, 359; Geographical Society's Expedition to, 131 ; French Exploration of, 131 ; Old Maps of, 149 ; Commander Goodrich on, 617 ; Stanley's " Through the Dark Continent," 175 ; Church Missionary Society's Expe- dition, 180; African Exploration Fund, 200; German Ex- ploration of, 387 ; Paul Soleillet's Expedition, 521 ; Gerhard Rohlfs' Exploration of, 521, 601, 681 ; African Poisons, 534; the Belgian Expedition, 601 ; Keith Johnston Expedition to Lake Nyassa, 646 ; the East African Expedition, 647 Agassiz (Alex.), Deep Sea Dredging off the Gulf of Mexico, 198; his New Laboratory, 465 Agriculture : Proceedings of the Aberdeenshire Agricultural Association, 640 Agricultural Ants, William E. Armit, 643 Airy (Sir Geo. B., F.R.S.), the Interior of the Earth, 41 ; an Intra-Mercurial Planet, 380, 495 ; Notice of, by Prof. A. Winnecke ( With Portrait), 689 Airy (Hubert), Blackburn's Double Pendulum, 617 Albinism in Birds, Herbert W. Page, 540 ; Edward Balfour, 568 ; Wm. Lyall, 568 Alcoholic Fermentation, Bernard's Experiments, 435 Al?ce, New Work on North American, 158 ; Gulf- Weed, Maiy P. Merrifield, 708 Algebra, W. II. H. Hudson, 64! Algeria, Triangulation of, 632 Algeria and Tunis, Playfair's Travels in, 91 Algiers, Education in, 321 " . . 1. Alimentary Substances, a Direct Method for Determining the Calorific Power of, 48 1 Alkalimetry, a New Method of Dr. Louis Siebold, 473 Allen (J. A.), a Fossil Sparrow-Like Bird, 204 AUman (Dr. G. J., F.R.S.), on Greek Geometry, 291 ; the Hydroids of the Gulf Stream, 326 Alpine Flowers, Dr. Hermann MuUer, 519 Alpine Salamander, the Artificial Transformation of, G, T. Bettany, 108 Alternate Vision, 169 Alternate and Stereoscopic Vision, \\. M. Fhnders Petrie, llj Alumina, W. A. Ross, 279 Alums, Electric Conductivity of Various, 48 Amazon, the U.S. Survey of the, 521 America : American Storm Warnings, Jerome J. Collins and Dr. Woeikof, 4, 31, 61, 517 ; American Journal of Science and Arts, 82, 536, 687 ; American Journal of Mathematics, 105, 316, 484; American Association, Meeting for 1878, 132, 316, 532 ; Ethnology of North- West America, 165 ; Jordan s Vertebrates of the Northern United States, 167 ; Lesquereaux s Tertiary Flora of North America, 189 ; American Geological Survey?, Prof. A. Geikie, F.R.S., 315, 694 ; Capt. W. A. Jones, 667; Prof. J. W. Judd, F.R.S., 538; Botany in America, Sir J. D. Hooker, P.R.S., 325 ; the Settlement of, by Asiatics, 359 ; American Geographical Society, 434 ; ^^^^}J^' ^"'l' Mexico, proposed New Work on the Botany of, 466; Prof. E D Cope on the Remains of a Permian Fauna in North America, 482 ; Prof. Hayden's Geological and Geographical Atlas of Colorado, 516; American Academy of Arts and Sciences 576 712; New American Scientific Books, 600; Microsco'pical Congress, 601 ; Heath Plant in, 682 ; Sea-Fish in Rivers, 681 ; _see a'so United States, New York, Phila- delphia, &c. Ammonites iphicerus, 106 t-, •!-> Ammonium, Selenate of, the Action of Heat upon, Dr?. Davy and Cameron, 472 Amphibians, the Tailed, W. H. Smith, 193 Amsterdam, Canals at, 632 Amu-Darya, its Return to its original Bed, 698 Analytical Machine, Babbages, 438 Anatomical Preparations for Museum and Class I urposes, L. C. IVTi3.ll ^12 " Anatomisch-physiologisch Atlas der Botanik," Dr. Arnold Dodel-Port, 317 .,..-, j Anatomy, Dunman's "Glossary of Biological, Anatomical, and Physiological Tenns," 614 Anderson (Richard) on Lightning Conductors, 554 Andree (Dr. R.), Ethnographical Parallels and Comparisons, 49 Andromedes I., Meteor Shower of, W. F. Denning, 568 Anemometer, Cup, Determination of the Constants of the. Dr. T. R. Robinson, F.R.S., 82 Angola, Heath's Expedition to, 697 Animal Intelligence, Geo. J. Romanes, 642 Annalen der Hydrographie, 159 Annalen der Physik und Chemie, 82, 242, 321, 560 Ansted (Prof. D. T., F.R.S.), "Elements of Physiography, 563 Anthropoid Apes at Beriin, 49 Anthropology : Anthropological Institute, no, 135,215,271, ^qi xn/L- Dr Bartley's Translation of "Topinard s Anthro- pology," 192 ; in France, 357, 436 ; German Anthropologists at Kiel, 466; International Congress of, 532; Anthropo- logical Exhibition at Moscow, 632 Anticyclones and Cyclones, Eustace Barham, 249 Antimony and Arsenic, Separation of, 679 ^^ ., , Ants : " Socialism " among, F. E. Colenso, 194 ; the Toilet Habits of, 386 ; the Mode of Recognition among, 3»6 ; Sir John Lubbock on the Habits of, 482 ; Agricultural, William E, Armit, 643 Ape.?, Anthropoid, at Berlin, 49 Apiculture in Germany, 6oi A aA IV IXDEX [Nature, Nov. 21, 1S70 " Appalachia," 360 Aquarium, the Edinburgh, 533 Arago, Portrait of, 575 Archaeological Association, 466 ; Institute, 393 ArchcBopteryx lithographicus, a new Specimen of, 65 1 Arctic Exploration : New Expeditions, 68; Capt.Nares' Narrative of the English Arctic Expedition, Il8 ; Mr. Gordon Bennett's Expedition, 131 ; Arctic Sea-Water and Ice, 135 ; Search for the Relics of the Franklin Expedition, 180; Markham's "Great Frozen Sea," 201 ; the Pandora re-christened the yeannette, 289 ; the Swedish North-East Passage Expedition, 308, 680 ; the Dutch Expedition, 360, 521 ; the Polar Colony Scheme, 521, 551 ; Capt. Tyson's Expedition, 521, 551, 681 ; the Nor- wegian Expedition, J. Gwyn Jeffreys, F.R.S., 568 ; the Voyage of the William Barends, 647 ; Discovery of a New Island in the Polar Seas, 697 Argentine Scientific Society, 601 Arithmetic, Automatic, John Sawyer, 327 Armenia, Science in, 502 Armit (William E.), Power of Stupefying Spiders possessed by Wasps, 642 ; Mimicry in Birds, 643 ; Agricultural Ants, 643 Arrow- Propulsion among the Maoris, 27 Arsenic and Antimony, separation of, 679 Articulate Vibrations, a Method of Recording by Means of Photography, Prof. E. W. Blake, 338 Artists, Physical Science for, J. Norman Lockyer, F.R.S., 29, 58, 87, 122, 154, 223 ; Tristram Ellis, 66; Robert J. Lecky, 116; F. Pollock, 249; G. Hubbard, 278; Rev. R. Abbay, 329 ; E. H. Pringle, 356 Asbestos for Bank-Notes, 23 Asia Minor, " Culture-Map" of, 434 Asia, Stanford's Maps of, 647 Aspergillus, an Ear Parasite, 182 Assyria, Hormuzd Rassam's Researches in, 653 Asten (Prof. Emil von), Death of, 502 ; Obituary Notice of, 552 Astronomy: Our Astronomical Colnmn, 19, 67, 103, 130, 147, 179, 199, 225, 261, 281, 306, 334, 358, 385, 426, 433, 464, 501, 520, 552, 569, 588, 618, 669, 696; Newcomb's Astro- nomy, 7 ; Catalogue of Works on Astronomy, 346 ; Astro- niical Society, see Royal ; see also Stars, Planets, &c. Atkinson (R. W.), Brewing in Japan, 521 Atlantic, North, the Norwegian Expedition, Dr. H. Mohn, 589 Atmosphere, the Geological Relations of the. Prof. T. Sterry Hunt, F.R.S., 475 Atmospheric Pressure over the North Atlantic, &c., 680 Aurora Observations of the Austro-Hungarian Arctic Expedi- tion, 1872-74, by Carl Weyprecht, 606 Aurora Borealis in Scandinavia, 632 Australia : Poisonous Lake in, Geo. Francis, 1 1 ; Heavy Rains in, 77 ; Guano Islands near, 159 ; a Twenty Years' Error in the Geography of, A. R. Wallace, 193 ; Use of Camels in, 337 ; Dr. Finsch's Expedition to, 387 ; Death of Two Aus- tralian Geologists, 389 ; Australian Monotremes, 464 ; Ex- ploration of North, 496 ; Gerard Kreflft and the Trustees of the Australian Museum, 575 Austria, Suicides among Students, 293 Austro-Hungarian Arctic Expedition, 1872-74, the Aurora Observations of, by Karl Weyprecht, 606 Automatic Arithmetic, John Sawyer, 327 Autophyllogeny : Dr. A. Ernst, 331 ; Dr. R. F. Hutchinson, 541 Axle, Lord Rayleigh, F.R.S., on Uniformity in the Rate of Rotation of an, III Ay?-Aye, the Anatomy and the Affinities of the, 645 Ayrshire Coast, the Rocks of the, 243 Ayrton(Prof.), the Electrical Properties of Bees'-Wax and Lead Chloride, 294; a New Determination of the Number of Electrostatic Units in the Electro-Magnetic Unit, 470 Babbage's Analytical Machine, 438 Back (Admiral Sir George, F.R.S.), Obituary Notice of, 227 Bacteria and Oxygen, 505 Baer (Prof, von), a Biography of, 434 Bailey (James B.), a Subject-Index to Scientific Periodical Litera- ture, 251 Baily (Walter), on the Effect of Various Substances on Polarised Light, 322 Baird's Annual Record of Science and Industry, 665 Balseonoptera, Geographical Distribution of, 242 Balfour (Edward), Albinism in Birds, 568 Balfour (F. M,), " Elasmobranch Fishes," Prof. E. Kay Lankester, F.R.S., 113 Ball (Prof. R. S.), Researches made'at Dunsink on the Anntial Parallax of Stars, 505 Ball (V.), Indian Ethnological Objects, 478 Balloons : Results of the French Commission on, 133 ; Experi- ments with, 206 ; Ascents in Paris, 291, 683 ; the Great Giffard, 318, 345, 371, 435, 534, 577, 705 ; Prof. Mende- leefT's Proposed Work on Aeronautics, 434 ; Military Balloon- ing, H. Baden Pritchard, 491 ; the Aeronautical Society, 576 ; Experiments at Woolwich, 620; Tissandier's "Histoire de mes Ascensions, 639 ; Escape of a Balloon, 653 Balmat (Jacques), Monument to, 393 Baltimore, Johns Hopkins University, 635 ; the Chemical Laboratory at, 181 Bamboo as a Paper Material, 50 Bank-notes, Asbestos for, 23 Barham (Eustace), Cyclones and Anticyclones, 249 Barometer, Diurnal Variations of the, 198 Barrett (S, T.), the Microphone, 540 Barrett (Prof. W. F.), the Microphone, 356 ; on the Telephone, 631 ; the Telephone, its History and Recent Improvements, 698 " Barrows, British," Greenwell and RoUtston's, Prof. BoyJ Dawkins, F.R.S., 429 Bartley (Dr. R.), Translation of Topinard's " Anthropolog)'," 192 Basaltic Rocks of Hawaii, 248 Basilica Spider, the Snare of the, 387 Bastian (Prof.), Expedition to Asia, 308 Bastie's Toughened Glass, Caution against, 653 Batavia Society of Arts and Sciences, 372 Bats, Catalogue of the Chiroptera in the British Museum, G. E. Dobson, 585 Battery, Byrne's, W. Ladd on, 506 Bavaria, Discovery of Prehistoric Remains in, 555 ; Lake- dwellings in, 601 Bedwell (F. A.), Hints to Workers with the Microscope, 141 Beer, the Scientific Brewing of, 503 Bees : in Java, 238 ; Frederick Smith on, 313 ; Fertilisation of ' Flowers by, 334; the Cell of the Bee, Edward Geoghegan, 385 Bees'-wax and Lead Chloride, the Electrical Properties of, 294 Beetz (Dr. W. von), •'Grundziige der Electricitatslehre," 300 Behn (Prof. W. F. Georg), Death of, 158 Belgium, Bulletin de I'Academie Royal de Belgique, see Bulletin Belt (Thomas, F.G.S.), Obituary Notice of, 570 Beluga at Westminster Aquarium, 1 59 Bennett (A. W.), " Henfrey's Botany," 217 Benson's "Facts and Figures for Mathematicians," and "New Mathematical Discoveries," 22 Benson (Col. R.), Indian Buildi ig Timber, 569 " Bentley and Trimen's Medicinal Plants," 50 Berkeley (Rev. M. J.), Obituary Notice of ^Dr. Thomas Thom- son, F.R.S , 15 Berlin : Geographical Society, 45, 76 ; Ethnographical Museum, 48 ; Anthropoid Apes at, 49 ; Paper Exhibition in, 424 ; Annual Meeting of Ornithologists, 575 Berne, Discovery of a Roman Town near, 207 Berthelot (M.), and M. Pasteur, 435 Berzelius (J. J. von). Centenary of his Birth, 683 Bettany (G. T.), the Transformation of the Alpine Sala- mander, 108 Bibliography : New Scientific Books, 317, 583, 600, 631 ; New German Scientific Books, 77, 134, 207, 503, 600; Ronald's Catalogue of Works on Electricity and Magnetism, 393 ; Catalogue of Works on Astronomy, 346 ; New American Scientific Books, 600 Bibra (Baron Ernst von). Obituary Notice of, 236 Bidder (George P.), the Phonograph, 302 Biela's Comet, 588 Binary Stars, a Centauri, 225 Binney (E. W., F.R.S.), a Fossil Plant, 555 Biology: Dunman's "Glossary of Biological, Anatomical, and Physiological Terms," 614 ; Biological Notes, 226, 252, 307, 385, 645 Bioplasm, the Influence of Light upon, 398 Bird (C), the Sea-Serpent Explained, 519 , Bird, a Fossil Sparrow-like, 204 Nalurf, N'm. 21, 1878] INDEX Birds: AlbiniMU in, Herbert W. Page, 540; Edward Balfour, 56S ; \Vm. Lyall, 568 ; Mimicry in, William E. Armit, 643 Birds' Eggs, the Colouring of, H. C. Sorby. F.R.S., 426 Birdvvood (Dr.), Handbook of British Indian Section of Paris Exhibition, 504 Birkbcck Institution, New Chemical Laboratory at, 608 Birmingham Natural History and Microscopical Society, 48, 262, 292, 436, 504 Black (Joseph), Prof. Crum Brown on, 346 Blackburn's Double Pendulum, 594; Hubert Airy, 617 Blaikley (G. D. J.), Brass Wind Instruments as Kesonators, 271 Blake (Dr. Clarence J.), th3 Phonograph, 249 Blake (Prof, E. W.), a Method of Recording Articulate Vibrations by Means of Photography, 338 Blanford (H. F.), Weather Forecast of the Monsoon Season, 287 ; the Genesis of Cyclones, 328 ; Janssen's New Method of Solar Photography, 643 Blanford (W. T.), the Pikermi nnd Siwalik Faunas, Pliocene, not Miocene, 501 Blister-beetles, tne Transformations of, 252 Blumenbach (Prof. Joh. F.), Monument to, 205 Blyth (James), the Microphone, 172, 181 Bock (Carl), Expedition to Padang, 132 Bolivar, the Land of, and its Products, 230 Bologna, Rendiconto delle Sessioni dell' Accademia delle Scienze dell' Istituto di Bologna, 428 Bolton, the Chadwick Museum, 291 Bombay, Meteorology of, in 1876, 199 Bone Caves in Styria, 618 Bonin Islands, Exploration of, 200 Bonn, University of, Legacy to, 82 Book-Case, a Rotating, 15 Boots, Manufacture of, in Japan, 49 Bordier (A.), the Greenland Eskimo, 16, 169 Boring Exploration, the Kentish, 469 Borneo, Expedition through, 289 Boron Fluoride, Action of, on Certain Classes of Organic Com- pounds, 337 Botany: lienfrey's Course of, 217, 278 ; Holmes' "Botanical Note-Book," 299; Dr. Arnold Dodel-Port's "Anatomisch- physiologischen Atlas der Botanik," 317 ; Dr. Asa Gray's " Synoptical Flora of North America," 325 ; Watson's " Index to North American Botany," 325 ; Royal Botanic Society, 425 ; Botanical and Horticultural Congress at Paris, 465, 553 ; Botanical Locality Record Club, 682 Bouillaud (M ), and the Phonograph, 630 Boulders, Erratic: in Switzerland, 206 ; in France, 2c6 ; B.A. Report on, 599 Boulger (G. S.), Scent and Colour in Flowers, 427 Boulogne, Geologists' Association at, 424 Boussingault (Prof. J.), the Physical Functions of Leaves, 672 Brahe (Tycho), his Correspondence, 306 "Brain," 64 Brass Wind Instruments as Resonators, 271 Braun (Prof. A.), his Library, 133 Brazil, Rainfall of, and the Sun-Spots, Orville A. Derby, 3S4 Bread, Real Brown, Prof. A. H. Church, 229 Brehm's " Thierleben," 496 ; E. H. Pringle, 518 Bremen Geographical Society, 46, 697 Brewing in Japan, R. W. Atkinson, 521 Bristol : University College, 108, 687 ; Lectures at, 683 Britanny, Earthquake in, 105 British Archteological Association, 466 British Association : Dublin Meeting. — Preliminary Arrange- ments, 132; Foreign Visitors, 261; the Excursion Com- mittee, 262 ; General Arrangements, Officers, Excursions, Visitors, &c., 236, 391 ; Tickets sold, 403; the Guide to Dublin, 403 ; Royal IDublin Society Soiree, 404 ; Mr. Howard Grubb's Great Telescope, 404 ; the Inaugural Address of the President, William Spottiswoode, LL. D., F. R.S., 404; General Arrangements and Proceeding-:, 436 ; the Question of the Reporting of the Proceedings, 436 ; Conversazioni and Entertainments, 437 ; the Meetings for 1879 and 1880, 437 ; the Attendance, 437 ; the New Assistant Secretary, 437 ; the Annual Grants, 438 ; Report of the Committee appointed to consider the Advisability and to estimate the Expense of Constructing Mr. Babbage's » Analytical Machine, 438 ; Third Report of the Committee for the Determination of the Mechanical Equivalent of Heat, 440; Report of the Committee on establishing a "Close Time " for Indigenous Animals, 440; Report of the Committee for commencing Secular Experiments on the Elasticity of Wires, 467 ; Report of the Committee ap- pointed to investigate the Effect of Propellers on the Steer- ing of Vessels, 468 ; Report of the Committee on the best Means of developing Light from Coal Gas, 468 ; Four- teenth Report of the Committee for Exploring Kent's Cavern, 468 ; Report of the Committee on the Fermanagh Caves, 469 ; Report of the Underground Water Committee, 469 ; Report on the proposed Kentish Exploration, 469 ; Report of the Earthworks Committee — Cscsar's Camp, Folkestone, Mount Caburn, Lewes, 470 ; Report of the Committee on the Fossils of the North-west Highlands of Scotland, 470; Report of the Committee on Mathematical Tables, 505 ; Report of the Committee on Oscillation Fre- quencies of the Rays of the Solar Spectrum, 505 ; Report of the Committee on Luminous Meteors, 505 ; Report of the Committee on Underground Temperature, 505 ; Report of the Committee on Erratic Boulders, 599 Section A {Mathematical and Physual). — Prof. Stanley Jevons, F.R.S., on the Pedetic Action of Soap, 440; Robert Sabine on Motions produced by Dilute Acids on some Amalgam Surface, 441 ; Prof. Silvanus P. Thompson on Certain Phenomena accompanying Rainbows, 441 ; Prof. W. E. Ayrton on a New Determination of the Number of Electrostatic Units in the Electromagnetic Unit, 470 ; Douglas Galton, F.R.S., on the General Results of some recent Experiments upon the Co-efficient of Friction be- tween Surfaces moving at High Velocities, 471 ; Researches made at Dunsink on the Annual Parallax of Stars, by Prof. R. S. Ball, 505 ; Description of an Equatorial Mounting for a Three-foot Reflector, by Lord Rosse, 506 ; R. Harley on the Stanhope " Demonstrator," or Logical Machine, 506 ; W. Ladd on Edmunds' Electrical Phonoscope, 506 ; W. Ladd on Byrne's Battery, 506 ; Solar Photography, Spec- troscopy, Flashing Gas-light, Sun's Heat, &c., &a, 506 Section B (Chefnical Science). — Opening Address by the Pre- sident, Prof. Maxwell Simpson, M.D., F.R.S., 441 ; Dr. Oliver J. Lodge on a Simplification of Graphic Formula?, 472 ; Dr. E. W. Davy and Dr. C. A. Cameron on the Action of Heat upon the Selenate of Ammonium, 472 ; Dr. E. W. Davy on the Action of Chlorine upon the Nitro- prussides, 473 ; Dr. Johnstone Stoney and Prof. Reynolds on the Spectrum of Chlorochromic Anhydrids, 473 ; Dr. Louis Siebold on a New Method of Alkalimetry, 473 ; William Thomson on the Estimation of Mineral Oil or Paraffin Wax when Mixed with other Oils or Fat, 473 ; Prof. Emerson Reynolds on some Double Salts of Glu- cinum, 473 ; Dr. H. Ramsay's Summary of Investigations on the Pyridine Series, 473 ; Dr. W. Ramsay on some of the Derivatives of Furfurol, 474 ; Prof. Letts on the The- tines, 474 ; Dr. Gladstone and Mr. Tribe on Aluminium Alcohols, 474 ; Alex. S. Wilson on the Amounts of Sugar contained in the Nectar of various Flowers, 474 ; W. Lant Carpenter on Waters from the Severn Tunnel Springs, 474. Section C {Geolooy). — Opening Address by the President, John Evans, D.C.L., F.R.S., 415; Prof. J. Sterry Hunt, F.R.S., on the Origin and the Succession of the Crystalline Rocks, 443 ; Prof. J. Sterry Hunt, F.R.S., on the Geological Relations of the Atmosphere, 475 ; Isaac Roberts on the Filtration ' of Sea- Water through Triassic Sandstone, 475 ; W. Ball on a New Geological Map of India, 475 ; VV. H. Baily on some Additional Labyrinthodont Amphibia and Fish from the Coals of Jarrow Colliery, near Castlecomer, County Kilkenny, 475 ; Joseph Nolan on the Ancient Volcanic District of Slieve Gullion, 475 ; Dr. John Evans, F.R.S., on some Fossils from the Northampton Sands, 476 ; W. H. Baily on a New Star-fish from Lower Silurian Caradoc Strata, Co. Wexford, and some New Carboniferous Limestone Mol- lusca from the County of Limerick, 476 ; Prof. E. D. Cope on the Saurians of the Dakota Cretaceous Rocks of Colorado, 476 ; Prof. E. Hull, F.R.S., on the Progress of the Geological Survey of Ireland, 476 ; the Cost of the | Survey Publications, 476 ; Alphonse Gages on the Influ- *' ence that Microscopic Vegetable Organisms had in the Production of some Hydrated Iron Ores, 476; Notes on some New Fossils, " Eribollia Mackayi" from the Quartz- ites of Loch Eribol and other parts of the Western Islands M VI mDEX [Nature, Noi>. 21, 1878 of Scothnd, 477 ; Rev, M. A, Close on the Extent of Geological Time, 477 ; Dr. Henry Hicks on some New Pre-Cambrian Areas in Wales, 477 ; Joseph Nolan on the Metamorphic and Intrusive Rocks of Tyrone, 477 ; J. W. Davis on the Occurrence of Certain Fish Remains in the Coal-Measures, and the Evidence of the Freshwater Origin of the Coal-Measures, 478 ; Prof. W. King on the Age of the Crystalline Rocks of Donegal, 478 ; W. Williams on the Cervus Megaceros, 478 ; Edward T. Hardman on the Influence of Strike on the Physical Features of Ireland, 506 ; Prof. O'Reilly on the Correlation of Lines of Direction on the Globe, 507 ; Edward T. Hardman on Hullite, a hitherto Undescribed Mineral from Carnmoney Hill, Co. Antrim, 507. Section D [Biology). — Opening Address in the Department of Zoology and Botany, by Prof. W. H. Flower, F.R.S., President of the Section, 419 Department of Zoology and Botany. — Prof. Cope on the Remains of a Permian Fauna in North America, 482 ; Sir John Lubbock, F. R.S., on the Habits of Ants, 482; Sir Walter Elliott on the Annual Increase of the Common Vole, 483 ; Dr. R. H. Traquair on the Genus Cteno- dus, 483 ; Dr. Allen Thomson, F.R.S., on Aberrant Sacrum connected with the Oblique Pelvis, 483 ; R. W. Sinclair on Recent Additions to the Irish Lepidoptera, 483 ; C. Spence-Bates, F.R.S., on the Present State of our Knowledge of the Crustacea, 483 ; H. II. Howorth on the Extinction of the Mammoth in Siberia, 483 ; Prof. Alex. Dickson, M.D., on the Stipules of Spergularia marina, 507 ; Prof. Dickson on the Inflorescence of Senebriera didytna, 508 ; Prof. Dickson on the 6- Celled Glands of Cephalotus and their Similarity to the Glands of Saracenia purpurea, 508 ; Exhibition of Plants of Isoeles echinospora, of Rumex maximus, Salix sadlori, 508 ; Notes on Naiadaceae, 508; Prof. W. C. Williamson, F.R.S., on the Supposed Radiolarians and Diatomacese of the Coal-Measures, 508 ; Alex. S- Wilson on the Association of an Inconspicuous Corolla with Proterogynous Dichogamy in Insect-Fertilised Flowers, 508 ; A. S. Wilson on Dimorphic Plants, 509 Department of Anatomy and Physiology. — Address by Dr. R. McDonnell, F.R.S., 445; J. A. W^anklyn and W. J. Cooper on a Direct Method for Determining the Calorific Power of Alimentary Substances, 481 ; Lawson Tait on the Occurrence of a Sacral Dimple and its Possible Significance, 481 Department of Anthropology . — Address by Prof . T. H. Huxley, LL.D., F.R.S., 445 ; Miss A. W. Buckland on the Pre- historic Monuments of Cornwall Compared with those in Ireland, 478 ; J. W. Knowles on Flint P'actories at Port Stewart and elsewhere in the North of Ireland, 478 ; V, Ball on some Ethnological Objects from India, 478 ; T. J. Hutchinson on Habits and Customs amongst some Tribes of Tropical Aborigines, 478 ; Henri Martin on the Races of Ancient Ireland, 479 ; H. H. Howorth on the Spread of the Slavs, 479 ; Prof. Daniel Wilson on some American Illustrations of the Evolution of New Varieties of Man, 479 ; A. L. Lewis on the Evils arising from the Use of His- torical National Names and Scientific Terms, 479 ; Prof. Huxley on the same, 479 ; Capt. R. T. Burton on the Tribes of Midian, 480; Prof. W. H. Flower, F.R.S., on the Methods and Results of Measuring the Capacity of Crania, 480 ; Prof. Huxley on the same, 481 Section E (Geography). — Opening Address by the President, Sir C. Wyville Thomson, F.R.S., 448; Dr. Phene on the Acquisition of Cyprus and Observations on some Islands in the Levant with Reference to Recent Discoveries, 483 ; Lieut. Kitchener on a Survey of Galilee, 483 Section F [Economical Science and Statistics). — Prof. Jevons, F.R.S., on the Periodicity of Crises and its Physical Ex- planation, 483 Section G [Mechanical Science). — Opening Address by the President, Edward Easton, C.E., on the Conservancy of Rivers and Streams, 452 ; G. J. Symonds on the Rainfall of Ireland, 484 ; W. H. Preece on Recent Advances in Telegraphy, 484; Mr. Wigham on the Irish Siren Fog Signal, 484 " Britihh Barrows," Greenwell and Rolleston's, Prof. Boyd Dawkins, F.R.S., 429 British Burmah : Panthays in, 95 ; Forest Flora of, S. Kurz, 517 British Isles, Stanford's Stereographical Map of, 19 British Medical Association, 393, 424 British Museum, the Natural History Collections, 328, 353, 403, 513, 588 British North America, Fisheries of, Dr. W. B. Carpenter, F.R.S., 170, 232 Broch (Dr. O. J.), Tables of Standards for Weights and Measures, 632 Brorsen's Comet of Short Period, 178, 589 Broun (J. Allan, F.R.S.), Cosmic Meteorology, 126, 151 Broun (Prof. Wm. LeRoy), the Microphone, 383 Brown (Prof. A. Crum, F.R.S.), Joseph Black, 346; Cyon's Researches on the Ear, 633, 657 Brown Bread, Real, Prof. A. H. Church, 229 Brown Institution, Resignation of Dr. Burdon Sanderson, 290 Brown (J.), Contact Electricity, 12 Brown (Dr. J. Croumbie), Pine Plantations on the Sand-Wastes of France, 666 Brown (Dr. R.), Countries of the World, 11 Browne (Montagu), Practical Taxidermy, 37 Browning (John), the Telephone and Deafness, 169 Bruno (Giordano), Statue of, 76 ; New Edition of his Works, 159 Brunswick, Prehistoric Remains in, 360 Buchanan (J. Y. ), Manganese Nodules in Loch Fyne, 628 Buckland (Miss A. W.), on the Stimulants of Savages, 351 ; tlie Prehistoric Monuments of Cornwall and Ireland, 478 Buffalo, the Weights of the Bones of the, 512 Buir, Earthquake at, 575, 632 " Bulb Garden," Samuel Wood, 693 Bulgarians, the Craniology of the, 290, 351 Bulletin de I'Academie des Sciences de St. Petersbourg, 186 Bulletin de I'Academie Royale de Belgique, 186, 242, 350, 403, 584 Burmah, British : Panthays in, 95 ; Forest Flora of, S . Kurz, 517 Burton (Capt. R. F.), Exploration of the Land of Midian, 76 ; Notes on the Tribes of Midian, 480 Butterflies, how they Escape from their Cocoons, 226 Byrne's Pneumatic Battery, W^. H. Preece on, iii ; W. Ladd on, 506 Cabbages, Remedy for Caterpillars on, 318 Cable, Submarine, the Electric Current in, 106 ; a Cable on Fire, 632 Cacciatore's Supposed Planet of 1835, 261 Ctesar's Camp, Folkstone, Excavations in, 470 Cailletet (Mons. de), Apparatus for Liquefying Gases, 46 Calderon (Prof. Salvador), the Darkness of Caverns, 427 Calendar, Perpetual, the Seth Thomas Clock Company's Ncsv Timepiece with, 575 Cambridge : University Intelligence, 53 ; Philosophical Society, 375; Caius Chemical Laboratory, 687; the Trinity Profesor- ship of Physiology, 711 Camels, Use of, in Australia, 337 Camera Lucida, a New, Dr. J. G. Hofmann, 312 Camphor, Oil from Crude, 49 Canals at Amsterdam, 632 Canterbury, the Archbishop of, and Degrees, 574 Canton, Tornado at, 394, 466 Capersburg, Discovery of Roman Structures at, 706 Caracas, Earthquake at, 105 Cardwell (Viscount), Address at Owens College, 598 Carhart (H. S.), Rayons de Cr^puscule, 540 Carniola, Excavations in, 652 Carpenter (Dr. A.), "Preventive Medicine in Relation to Public Health," 248 Carpenter (Dr. P. P.), his Collection, Principal Dawson, 116 Carpenter (Dr. W. B., F.R.S.), Fisheries of British North America, 170, 232 Carpenter (W, Lant), Notes on the Waters from the Severn Tunnel Springs, 474 Carrier Pigeons, Utilisation of, 682 Cartago, Earthquake at, 600 Caruel(Prof. D.), Classification of the Vegetable Kingdom, 646 ; La Morfologia Vegetale, 666 Cassell, Meeting of the German Naturalists' Association, 316, 435, 552, 576 Cataclysmic Theories of Geological Climate, Tames Croll, F.R.S., 187 Caterioillars, Remedy for, on Cabbages, 318 Nature, Nov, 21, 1878] INDEX VU Cathetoraeter, the, 467 Cavaille-Coll (A.), on Musical Pitch, the French Diapason Normal, Scheibler's Tuning- Fork?, &c., Alex. J. Ellis, F.R.S., 381 Caves : Kent's Cavern, 468 ; a Remarkable, in Kentucky, 575 ; Bone, in Styria, 618 ; the Darkness of Cavern-:, Prof. Salvador Calderon, 427 Cazin (A,), " La Spectro?copie," 564 Cecil (Henry), Power of Stupefying Spiders possessed by Wasps, 625 Cell of the Bee, Edward Geoghegan, 385 Cell, Peaucellier, Horace Darv^dn on the, 383 Cephalotus, the 6- Celled Glands of, Prof. Alex. Dickson, 508 Cervus megaceros, W. Williams, 478 Chairs, Easy, the Science of, 637 Challenger Report, Progress of the, Prof. Sir Wyville Thomson, F.R.S., 534 Chamrcleons, Sense of Fear in, R. Morton Middleton, 696 Chambers (Fred.), Meteorology of Bombay, in 1876, 199; Sun- spots and Weather, 567 ; Sun and Earth, 619 Chartres (R.), Circulating Decimals, 291 Chateau (Prof. J. L.), Death of, 290 Chemical Society, 55, no, 164, 271, 323 ; Soiree, 157 ; Research Fund, 465 ; the Faraday Lecture, 651 Chemistry: Jahresbericht der Chemie, 105; "Kolbe's Inor- ganic," 106 ; German Works on, 106 ; the Chemical Attributes of Vegetable Physiology, S. II. Vines, no; the Scientific Aims and Achievements of. Prof. Aug. Kekule, 210 ; Payen's Industrial, 218 ; a New Triumph of Chemical Synthesis, 251 ; Chemical Notes, 336, 679 ; Tidy's Handbook of, 586 ; Miller's Elements of, 614 Chesapeake Bay, Oyster Beds of the, 653 Chiddey (Alfred), the Telephone, 94.; the Microphone in In- direct Circuit, 464 Chili, Meteorological Stations in, 600 China : Chinese Medical Education, 23 ; Cyclone on Coast of, 206; Exploration of, 228; the River "China's" Sorrow," 228; Official Rank Hereditary in, 424; Robert Swinhoe's Collection of Chinese Birds, 465 ; P. C. H. Lepper's attemp- ted Journey to, 599 ; a New Chinese Magazine, 601 ; John McCarthy's Journey through, 68 1 ; Missionjiry Exploration of, 681 ; proposed Railway from Taku to Tientsin, 697 Chiroptera, Catalogue of, in the British Museum, G. E. Dobson, Chlorine, the Action of, upon the Nitroprussides, Dr. E, W. Dav)', 473 Chlorochromic Anhydrids, the Spectrum of. Dr. Johnstone Stoney and Prof. Reynolds, 473 " Choice and Chance," W. A. Whitworth, 666 Christiania, Discovery of Fossils in the Bay of, 263 \ Christie (Alex. Craig), Menziesia ctcrulea, 66 Christy (Thomas), Hydro Incubation, 542 Church (Prof. A. H.), Real Brown Bread, 229; Gelatine as a Food-Preserver, 546 Cincinnati Observatory, 103 ; Society of Natural History Journal, 636 Circulating Decimals, R. Chartre?, 291 ; Edmund P. Toy, 541 ; Thomas Muir, 617 Circumnavigation, Lieut. Biard's Student Expedition round the World, 308 Cissbury, Description of a Male Skeleton found at, 215 Claret, New Flavouring Dye for, 23 Clark (J. Edm.), the Meteor of May 12, 142 ; Earth Pillars, 617 Clark (Latimer), Time and Longitude, 40 Clarke and McLeod on the Telephone, 1 1 Clarke (Rev. W. B., F.R.S.), Death of, 205; Obituary Notice of, 389 Classification of the Vegetable Kingdom, Prof. Camel's, 646 Cleistogamous Flowers in Grasses, 253 Clifford (Prof. W. K.), "Elements of Dynamic," 89 Climatology, Climate in Higher Latitudes during Geological Periods, 27 Clock : Herr Noll's Decimal, 133 ; a New, with Perpetual Calendar, 575 Close (Rev. M. A.), on the Extent of Geological Time, 477 " Close Time," Report on Establishing a, for Indigenous Animals, 440 Cloud, Dr. Hellman's Observations on, 68c Clousel, Discovery of a Grotto at, 653 Club-Root, Prof. E. Perceval Wright, 271 Coal, Prof. T. E. Thorpe's History of, 133 Coal-Field, a New, near Hemsworth, 394 Coal-Gas, the best Means of Developing Light from, 468 Coal-Measures, on the Occurrence of Certain Fish Remains in, J. W. Davis, 478 ; the Supposed Radiolarians and Diato- macece of the. Prof. W. C. Williamson, F.R.S., 508 Coccyx, Abnormal, Dr. Andrew Dunlop, 94 Coffee, Preservation of, in Salt Water, 344 Coimbra, the University of, 374 Colenso, (F. E.), Socialism in South Africa, 194 Collins (Jerome J.), American Storm Warnings, 4, 31, 61 Cologne, Earthquake at, 504 Colorado, Geological Maps of, 290 ; Saurians from the Cre- taceous Rocks of, 476 ; Geological Exploration of, 704 Colour, the Sense of, in Men, 371 ; the Origin and Distribution of Organic, W. Saville Kent, 523 Colour-Blindne-s in Relation to the Homeric Expressions for Colour, Dr. William Pole, F.R.S., 676, 700 Comets : Tempel's Comet, 1873, II., 67, 130, 281, 358, 385 ; Reappearance of Encke's Comet, 104, 131, 358, 589; Brorsen's Comet of Short Period, 179, 589; Periodical Comets in 1879, 306; a New Comet,' 307 ; the New Comet (Lewis Swift), 335, 520; Biela's Comet, 588; Prof. Newton (U.S.), on the Origin of, 687 Complementary Colours, 323 Composite Portraits, Francis Galton, F.R.S., 96 Conder (Lieut. C. R.)," Tent- Work in Palestine," 538 Conservation of Energy, Dr. G. Krebs on, 706 Constantinople: Musuem of Antiquities at, 21; Earthquake at, 77 Contact Electricity, J. Brown, 12 Cook (Capt.), Colossal Statue of, 263; Discovery of a MS. Copy of his Diary, 496 Cope (Prof. E. D.), the Structure of Coryphodon, 67; on the Saurians of the Dakota Cretaceous Rocks of Colorado, 476 ; on the Remains of a Permian Fauna in North America, 482 Copper, AUotropic Modification of, 336 " Copra " as Food for Cattle, 49 Coralline Oolites of Yorkshire, W. H. Huddlestone, 136 Corea, 68 ; the Condition of, 317 ; Timber from, 317 Ccrfield (Dr. W. H., F.R.S.), Opening of Museums on Sundays, 170, 194, 220 Cornu (M. A.), Elected to the Academy of France, 262 Cornwall and Ireland, the Prehistoric Moniunents of, 478 Corpura Volcano, the, 423 Correlation of Lines of Direction on the Globe, Prof. O'Reilly, 507 Coryphodon, the Structure of, Prof. E. D. Cope, 67 Cosmic Meteorology, J. Allan Broun, F.R.S., 126, 151 Cosmical Results of the Modern Heat Theory, J. Loschmidt, 184 Costa Rica : Grasshoppers in, 344 ; Earthquake in, 600 Cotta (Bernhard von), " Geologic der Gegenwart," 380, 487 Craniology, Prof. W. H. Flower, F.R.S., on the Methods and Results of Measuring the Capacity of Crania, 480 ; the Varia- tion of Volume of the Cranium, 324 Crannog, Scottish, Discovery of a, Dr. Robert Munro, 695 Crinoids, Transition Forms of, in American Palaeozoic Rockp, 646 Crises, Prof. Jevons on the Periodicity of, 483 Crofton(M. W., F.R.S.), " Elements of Applied Mechanics," 247 Croll (James, F.R.S.), Cataclysmic Theories of Geol(^caI Climate, 187 Cross (Chas. R.), Helmholtz's Vowel Theory and the Phono- graph, 93 Crustaceans, Stridulating, 53, 95; C. Spence-Bate, F.R.S., on the, 483 Cryptogamic Society of Scotland, 553, 652 Crystals, the Planes of Symmetry in, 163 Crystalline Form of Chemical Substances, Prize for Essay on. Crystalline Rocks : the Origin and Succession of. Prof. J. Sterry Hunt, F.R.S., 443 ; of Donegal, 478 Crystallography, Groth's Zeitschrift, 106 Ctenodos, the Genus, 483 Cua, Earthquake at, 105 Culley (R. S.), "Practical Telegraphy," 166 " Culture-Map" of Asia Minor, 434 Cumberland Association, Annual Meeting, 21 Cumulative Temperature, Wm. F, Stanley, 41 Vlll INDEX [Nature, Nov. 2i, 1878 Curioni (Guilio), Death of, 599 Currents, Ocean, M. Zoppritz on, 321 Cycloid, the, and Cycloidal Curves, R. A. Procter, 355 Cyclones : on Chinese Coast, 206 ; and Anticyclones, Eustace Barham, 249 ; the Genesis of, H. T. Blanford, 328 ; and the Winter Gales of Europe, S. A. Hill, 616 ; William Ellis, 641 Cyon's Researches on the Ear, Prof. A. Crum Brown, F.R.S., 633, 657 Cyprus : an Account of, 302 ; the Climate of, 335 ; Proposed Botanical Garden at, 423 ; Kiepert's Map of, 434 ; Dr. Phene on, 483 ; New Maps of, 520 ; French Mission to, 681 ; Hamilton Lang's work on, 693 Daintree (R.), Obituary Notice of, 389 D'Albertis (L. M.), his Expedition to New Guinea, Scientific Results of, 72 ; Journey to London, l8l ; Arrival there, 359 ; his Zoological Collections, 465 Dallinger (Rev W, H., F.R.S.), on the New "Oil Immersion" Object-Glass constructed by Carl Zeiss, of Jena, 65 ; the Life- History of a Septic Organism, 102 Daltonism, Researches on, 186 Danube, the "loess" Formations of the, 207 D'Anvers (N.), Heroes of South African Discovery, II Daphnoidoe, Decorative Colouring in, 226 Darmstadt, Notizblatt des Vereins fiir Erdkunde, 186 Darwin (Dr. Charles, F.R.S.), Transplantation of Shells, 120 ; Elected Member of the Paris Academy, 392 Darwin (Francis), the Nutrition of Drosera rotundifolia, 153 Darwin (G. H.), some Results of the Supposition of the Vis- cosity of the Earth, 265 ; on the Precession of a Viscous Spheroid, 580 Darwin (Horace), Peaucellier Cell, 383 Davies (D. C), Slate and Slate Quarrying, 10 Davis (J. W. ), on the Occurrence of Certain Fish Remains in the Coal-Measures, 478 Davis (J.) and F. Arnold Lees' " West Yorkshire," 276 Davis (Prof. W. Monroe), Death of, 652. Davy (Dr. E. W.), the Action of Chlorine upon Nitro- Prussides, 473 ; and Dr. Cameron on the Action of Heat upon Selenate of Ammonium, 473 Dawson (Principal J. W.), Dr. P. P. Carpenter's Collection, 116 ; a Fossil Plant — Misquotation, 696 Dawkins (Prof. W. Boyd, F.R.S.), Extinct and Recent Irish Mammals, 169 ; the Sinks of the Animal World, 537 ; De Ranee's Superficial Geology of South- West Lancadiire, 561 Deafness and the Telephone, 132, 169 Decimals, Recurring, T. Chartres, 291 ; Edmund P. Toy, 541 ; Thomas Muir, 617 Decimal Weights, Measures, &c.. Uniform, 504 Deep-Sea : Dredging off the Gulf of Mexico, Prof. E. Perceval Wright, 198 ; Soundings, Wire for, 357 ; Thermometer, a New, 348 Degrees, the Archbishop of Canterbury and, 574 Deimos, Satellite of Mars, 618 Delafosse (Prof.), Death of, 681 De la Rue (Dr. Warren, F.R.S.) and Dr. Hugo W. MuUer, F.R.S., on Electric Discharges in Gases, 525, 547 Demavend, Mount, 647 Demography, Congress of, 237 "Demonstrator," the Stanhope, 506 Denning ( W. F. ), the Meteor Shower of Aquarids (July), 356, 384 ; Meteor Shower of Andromedes I., 568 Derby (Orville A.), Rainfall of Brazil and the Sun-Spots, 384 " Deutsche geographische Blatter," 46 Devonshire Association for the Advancement of Science,' &c., 392 Dewar (Prof. J., F.R.S. ), Experiments in Electro-Photometry, 186 ; his Lecture on " Dissociation," 437 Dewar and Liveing (Profs.), on the Reversal of the Lines of Metallic Vapours, 109, 321 Diapason Normal, the French, A. Cavaille-Coll on, 381 Diarrhoea, New Remedy for, 49 Diatomaceae and Radiolarians, the Supposed, of the Coal- Measures, Prof. W. C. Williamson, F.R.S., 508 Dickson (Prof. Alex.), on the Stipules of Spergularia marina, 507 ; on the Inflorescence of Senebiera didyma, 508 ; on the 6-Celled Glands of Cephalotus, 508 ; Isoetes echinospora, 508 Didus and Didunculus, Prof. A. Newton, F.R.S., 251, 331 ; Searles V. Wood, 301 Dilatation of Bodies, on a Universal Law Relative to, 608 "Dissociation," Prof. Dewar's Lecture on, 437 "Divide et Impera," E. W. White, 142 Dixon (Charles), Landrails, 116 Dobson (G. E.), Catalogue of the Chiroptera in the British Museum Collection, 585 Dobson (Thomas), Whirlwind, 250 Dodel-Port (Dr. Arnold), " Anatomisch-physiologischen Atlas der Botanik," 317 Donegal, the Crystalline R.ocks of, 478 Double Stars, 334 ; Measures of, 225 Dowling (Henry P.), a Quadruple Rainbow, 142 Downes (Dr. Arthur) and T. P. Blunt, on the Influence of Light upon Bioplasm, 308 Draper (Dr. Henry), the Eclipse of the Sun, 462 Draper (Dr. J. C), on the Presence of Dark Lines in the Solar Spectrum, which correspond closely to the Lines of the Spectrum of Oxygen, 654 Dredging, Deep-Sea, off the Gulf of Mexico, Prof. E, Perceval Wright, 198 Dress, Sexual Selection and, 632 Drew (Dr. Joseph), the Sea-Serpent Explained, 489 Drosera rotundifolia, the Nutrition of, Francis Darwin, 153 Druce (G. C), Menziesia ccerulea, 116 Dublin, the British Association Guide-Book, 403 Dudgeon (Dr. R. E.), Examination of Small Organisms in Water, 196 Dudley (W. L., M.D.), Hearing of Insects, 568 Duelling in German Universities, 242 Dundee Free Library Report, 159 Dunlop (Dr. Andrew), Abnormal Coccyx, 94 Dunman (Thomas), " Glossary of Biological, Anatomical, and Physiological Terms," 614 Diirkheim, Discovery of Prehistoric Remains near, 555 Durville (H.), " La Revue Magnetique," 615 "Dust- Whirl," Observations on a. Prof. Francis E. Nipher, 488 Dutch Meteorological Institute, 680 Dutch North Polar Expedition, 360, 521 Dutch Society of Sciences, 158 Dyer (Prof. W. T. Thiselton), Opening of Museums on Sun- days, 194 Dynamic, Prof. Clifford's Work on, 89 "Dynamics of a System of Rigid Bodies," E. J. Routh, F.R.S,, 247 Eagles, New Work on, 684 Ear, Cyon's Researches on the. Prof. A. Crum Brown, F.R.S., 633. 657 Earth: the Interior of the, Sir Geo. B. Airy, F.R.S., 41 ; Re- markable Changes in the Earth's Magnetism, Capt. F. J. Evans, C.B., F.R.S., 80; some Results of the Supposition of the Viscosity of the Earth, 265 ; Population of the, 338 ; the Theory of Internal Heat of the, &c., 397 ; the Figure and Size of the, Karl Maria Friederici, 556, 577, 602 ; the Earth and Sun, F. Chambers, 619 Earth Pillars, James H. Midgley, 569 ; J. Edmund Clark, 6 1 7 Earth's Orbit, Nearest Approximations of Small Planets to the, 225 Earthquakes : at Constantinople and Nicomedia, 77 ; at Cua, 105 ; at Gotdngen, 105 ; at Caracas, 105 ; in Britanny. 105 ; in Venezuela, 130 ; in Japan, 182 ; in Lisbon, 182 ; in France, 263 ; in the Island of Tanna, 262 ; on the Philippines, 265 ; at Jenbach, 393 ; at Innspruck, 466 ; at Cologne, 503 ; at Rocca di Papa, Italy, 533 ; at Buir, 575 ; at the Pic-du Midi Obser- vatory, 600 ; at Osterath, 600 ; at Cartago, Costa Rica, 600 ; at Buir, 632 ; near the Hudson, 683 ; and Volcanic Phenomena during 1877, 241 ; Curious Phenomenon near Florence, 532 ; Records of, in Japan, 373 Earthworks, B.A. Report on, 470 Easton (Edward, C.E.), Opening Address in Section G at the British Association, 452 Eastward Progress of Terrestrial Magnetism, Prof. Balfour Stewart, F.R.S,, 38 Easy Chairs, the Science of, 637 Eberstein's Walking Stick for Naturalists, 372 Eclipses : the Solar Eclipse of July 29, 1878, 261, 353, 394, 425- 430; Prof. Newcomb's Instructions for Observations, 181; J. Normal} Lockyer, F.R.S,, 401, 457; Dr. Henry Draper, Nature, Noi'. 21, 1878] INDEX IX 462 ; Solar, of May 16, 1882, and August 18, 1887, 199 ; Total Solar, of 1883, 261; Solar, of May 28, 1900, 358; Eclipse Spectroscope, J. Norman Lockyer, F.R.S., 224; the Lunar Eclipse of August 12, 385 Edinburgh, Aquarium at, 533 Edison's Phonograph, 116 ; his Telephone, 631 ; his Inventions, 674 ; " Edison Electric Light Company," 705 Edmunds' (Dr. J.), Microscopy, the Immersion Paraboloid, 278 Edmunds' Electrical Phonoscope, W. Ladd, 506 Education, "Excursional," 76 Educational Travel for Children, 456 Educational Appliances at the Paris Exhibition, 436 Egypt : Dr. F. Mook's Excavations in, 372 ; Egyptian Papyrus at the Paris Academy, 652 Elasmobranch Fishes, F. M. Balfour's Monograph on, Prof. E. Ray Lankester, F.R.S., 113 Elasmotherium, the, 387 Electric Light: Electric Lighting in Paris, 159, 182, 262, 317; Spectrum of Jablochkoff's, E. Walker, 384; the Electric Arc among the Gas Shares, 609; Dr. C. W. Siemens, F.R.S., on Electric Lighting, 650 ; Experiments in London Streets, 682 ; the Cost of, 682 ; the Edison Electric Light Company, 705 Electric Discharges in Gases, Drs. Warren De La Rue, F.R.S., and Hugo W. Miiller, F.R.S., 525, 547 Electricitatslehre, Gnindzuge der. Dr. von Beetz, 300 " Electricite," the, 206 Electricity, " a Fortunate Escape," 195 Electricity and Magnetism, Catalogue of Works on, 393 " Electricity and Magnetism," George Porter, 615 Electricity, Contact, J. Brown, 12 Electro-Magnet, a Receiving Telephone, F. G. Lloyd, 488, 540 Electro Magnetic Unit, the Number of Electrostatic Units in, 470 Electrometer, Thomson's Quadrant, the Determination of the Scale Value of, iio Electro-Photometry, Experiments on, Prof. J. Dewar, F.R.S. , 186 "Elements," Are the, Elementary? M. M. Pattison Muir, 592, 625 Elephant Tusk found near Geneva, 683 Elephants, Indian, Utihsation of, 552 Elliott (Sir W.), the Annual Increase of the Common Vole, 483 Ellis (Alex.J. F.R.S.), the Phonograph, 38 ; Mons. A. Cavaillc- CoU on Musical Pitch, the French Diapason Normal, Scheibler's Tuning Forks, &c., 381 Ellis (Tristram), Science for Artists, 66 Ellis (William), the Magnetic Storm of May 14, 1878, 641 ; Cyclones and the Winter Gales of Europe, 641 Elwes' " Ocean and Her Rulers," 380 Ely (Talfourd), Classes for Women at University College, 143 ; University College Jubilee, 195 " Enchainements du Monde Animal," Prof. Gaudry's, 537 Encke's Comet, Reappearance of, 104, 131, 589 "Encyclopaedia Britannica," Vols. 7 and 8, 691 ■ Endosmose of Gases through Lungs, 106 Endowment of Research, Prof. E. Ray Lankester, F.R.S., on, 610 ; the Lancet on State Aid to Science, 629 Engadine, the Upper, Guide to, 601 Entomological Commission (U.S.) Report, 554 Entomological Society, 53, 55, m, 295, 374, 511, 584, 688 Equatorial Mounting for a Three-foot Reflector, Lord Rosse on, 306 " Eribollia Mackayi" New Fossils, 477 Ernst (Dr. A.), Autophyllogeny, 331 ; on the Wax of Poecil- optera, 487 ; Spontaneous Combustion of Wasps' Nests, 487 Erratic Boulders, B.A. Report on, 599 Eskimo, the Greenland, A. Bordier, 16, 169 Ethnographic Congress at Paris, 318, 599 Ethnographical Parallels and Comparisons, Dr. R. Andree, 49 Ethnology of North-West America, Rev. A. H. Sayce, 165 Ethnological Objects from India, 478 Etna, Mount, Proposed Observatory on, G. F. Rodwell, 587 Ettingshausen (Andreas von). Obituary Notice of, 197 Euclfd, I., II., W. H. Hudson, 641 Kurysaurus raincourti, 28 Evans (Capt. F. J., C.B., F.R.S.>, Remarkable Changes in the Earth's Magnetism, 80; and Sir William Thomson, F.R.S., on the Tides of the Southern Hemisphere and the Mediter- ranean, 670 Evans (John, F.R.S.), Opening Address in Section C at the British Association Meeting at Dublin, 415 ; on the Cost of the Geological Survey Publications, 476 ; on some Fossils from the Northampton Sands, 476 ; on the Cervus megaceros, 478 Evans (M. S.), Notes on some Natal Plants, 543 Evershead (Sydney), a Meteor, 519 Evolution, Prof. Haeckel on, 509 Ewing (Prof. J. A.) and Prof. Fleeming Jenkin on the Phono- graph and Vowel Sounds, 340, 394, 454 Extinct and Recent Insh Mammals, Prof. A. Leith Adams, 141 ; Prof. Boyd Dawkins, 169 Failures, Commercial, and Sun-Spot Periods, 372 Falkland Islands, Wingless Insects of the, H. N. Moseley, F.R.S., 619 Falls of Niagara, Utilisation of, 393 " Familiar Wild Flowers," F. E. Hulme, u Faraday Lecture of the Chemical Society, 651 Farmer's Weather Indicator, 621, 630 Farming and the Use of Sewage, 133 Fanning in India, 219 Fata Morgana at Halberstadt, 466 Faye (M.), his " La Meteorologie Cosmique," 126, 151 Payrer (Sir J., F.R.S.), the Size of the Indian Tiger, 219; a White Grouse, 518 Fendler (Augustus), Collections of Ferns from Trinidad, 466 Fenland, the. Past and Present, Miller and Skertchly, 514 Fermanagh Caves, the Exploration of, 469 Fermentation, Brewing in Japan, 521 Ferns, Prof. J. Robinson's New Work on, 555 Fertilisation of Flowers, 543 ; by Bees, 334 Fetich ism in a Terrier, 77 Figure and Size of the Earth, Karl Maria Friederici, 556, 577, 602 Finsch (Dr. O.), Resignation of his Post and Mission to the Pacific, 531 Fish : Sea-Fish in Rivers, 681 ; United States Fish Commission, 682, 704 Fisher (O. P.), Meteor, 643 Fisheries of British North America, Dr. W. B, Carpenter, F.R.S., 170, 232 Fisheries, Comparative Value of German, 206 Flames, the Temperature of, 345 Fleas, Freshwater, Decorative Colouring in, 226 Flint Factories at Port Stewart, &c., 478 Floating Magnets, Sir William Thomson, F.R.S., 13; Prof. A. M. Mayer, 258; C. S. Pierce, 381 Flower (Prof. W. H., F.R.S.), Opening Address in Section D (Department of Zoology and Botany), at the British Associa- tion Meeting at Dublin, 419 ; on the Methods and Results of Measuring the Capacity of Crania, 480 "Flowers, Familiar Wild," F. E. Hulme, 11 " Flowers," J. E. Taylor, 276 Flowers : Scent and Colour in, G. S. Boulger, 427 ; on the Amounts of Sugar contained in the Nectar of Various, Alex. S. Wilson, 474; Fertilisation of, 543; by Bees, 334; Different Forms of, on the same Plant, 519 Flowers and Ferns of the United States, Thomas Meehan, 615 Fluid Columns, the Structure of, which are affected by Sound, R. H. Ridout, 604 Fluorescence, recent Researches on, 107 Fly-Orchis, Dr. Hermann Miiller, 221 Flying- Fish, the Movements of, through the Air, 373 Fog Signal, the Irish Siren, 484 ; a New, Prof. P. G. Tait, 371 Folkestone, Excavations in Ceesar's Camp, 470 Food-Preserver, Gelatine as a. Prof. A. H. Church, 546 Fordos (M. J.), Death of, 467 Foreign Orders, 691 Forel (Dr. F. A.), the Seiches of the Lake>f Geneva, ico Forest Flora of British Burma, S. Kurz, 517 YohhWs: ■■" Eribollia Mackayi," 477; Fossils of the North- Western Highlands, 470; Discovery of a new Fossil at Sheppey, 554 ; a Fossil Sparrow-Like Bird, 204 ; a P'ossil Plant, A. E. W. Binney, F.R.S., SS5 ; a Fossil Plant— A Misquotation, Prof. J. W. Dawson, 696 Fossil Flora of Great Britain, Prof . W. C. Williamson, F.R.S,, 35 , Fossiliferous Tertiary Rocks on the Grand Bank and George Bank, A. E. Verrill, 620 Foster (P. le Neve), Proposed Testimonial to, 236 'INDEX [Natun, Nffv. 21, 187S Foucault (Leon), the Papers of, 601 Fourier's "Analytical Theory of Heat," Freeman's Translation of, 192 France : French Association for the Advancement of Science, 21, 48, 205, 392, 435, 465, 509, 551 ; Officers of, 236; Ex- cursions, 262 ; Geography at, 55 1 ; Meteorology in France, 21, 96 ; the French Meteorological Service, 134 ; the Societe Chimiqite de Paris, 182 ; Erratic Boulders in, 206 ; Earth- quake in, 263 ; Proposed School of War, 291 ; Anthropology in, 357 ; the Central Bureau of Meteorology, 372, 435, 601 ; A. Cavaille-CoU on the French Diapason Normale, 381 ; the Meteorological Commissions, 424 ; School Building in, 456 ; , Map of, 496 ; French Geographical Societies, 521 ; Bulletin of, 521; Dr. Siemens, F.R.S., on Scientific Education in, 574; Pine Plantations on the Sand-Wastes of, Dr. 1. Croumbie Brown, 666 ; Commission on Running Waters, 683 ; see also Paris, &c. Francis (George), Poisonous Australian Lake, ii Francis (Gerald B.), the Microphone, 383 Frankfort-on-the-Main, Historical Museum 'at, 291 Franklin Expedition, the Relics of the, 228 Franklin Institute, Journal of the, 636 Frazer (Persifor), Examination of the Phonograph Record under the Microscope, loi Freeman (A.), Translation of Fourier's " Analytical Theory of Heat," 192 Freshwater Fleas, Decorative Colouring in, 226 Friction, the Coefficient of, between Surfaces moving at High Velocities, Douglas Galton, F.R.S., 471 Friedel (Prof. C.) appointed Member of Paris Academy, 290 Friederici (Karl Maria) the Figure and Size of the Earth, 556, 577. 602 Frobisher (Sir Martin), Jones' Life of, li Frog, Dr. Burdon- Sanderson and F. J. M. Page on the Rhyth- mical and Excitatory Motions of the Ventricle of the Heart of the, 293 Frogs, Tree, 271 Friis (F. R.), Tycho Brahe's Correspondence, 306 Fuchs (Prof. C. W. C), Volcanic Phenomena and Earthquakes during 1877, 241 Fuel, Gas as, M. M. Pattison Muir, 34 Furfurol, some of the Derivatives of. Dr. W. Ramsay, 474 Gabb (Prof. W. M.), Obituary Notice of, 285 Galilee, a Survey of, Lieut. Kitchener, 483 Gallium and Aluminium, Alloys of, 136 Galton (Douglas, F.R.S.), General Results of some Recent Ex- periments on the Coefficient of Friction between Surfaces moving at High Velocities, 471 Galton (Francis, F.R.S.), on the Advancement of Geographical Teaching, 337 ; Composite Portraits, 96 Galton (J. C.), Recent Observations upon the Placentation of Sloths, 686 Galvanometer, a New, for Strong Currents, Eugen Obach, 707 Galvanometer for Lecture Purposes, Prof. S. P. Thompson, 264 Gamgee (Prof., F. R.S.), his New Work on the Physiological Chemistry of Animal Bodies, 653 Gardner (J. S.), Lesquereux's Tertiary Flora of North America, 189 Gas as Fuel, M. M. Pattison Muir, 34 Gas, Coal, the Best Means of Developing^ Light from, 468 Gas Shares, the Electric Arc among the, 609 Gases, Heat and the Transpiration of, 163 Gases, Electric Discharges in, Drs. Warren De la Rue, F. R. S., and Hugo W. Miiller, F.R.S., 525, 547 Gaudry (Albert), "Les Enchainements du Monde Animal dans les Temps Geologiques, Mammiferes, Tertiares," Prof. Boyd Dawkins, F.R.S., 537 Gauss Monument, the, 435 Geikie (Prof. A., F.R. S.), American Geological Surveys, 315, 516 ; Hull's Geology and Geography of Ireland, 354 ; Ame- rican Exploration, 694 Geikie (Dr. James, F.R.S.), the Glacial Phenomena of the Long Island or Outer Hebrides, 187 Gelatin as a Food-Preserver, Prof. A. H. Church, 546 Genesis of Cyclones, H. F. Blanford, 328 Genesis of Limbs, St. George Mivart, F.R.S., 282, 309, 331; Prof. G. M. Humphry, F.R.S., 427 Geneva ; Seiches of the Lake of, Dr. F. A, Forel, loo ; Society of Physics and Natural History, 344, 512, 536, 683 ; Dis- covery of Elephant Tusk near, 683 Geoghegan (Edward), the Cell of the Bee, 385 Geography: Geogi-aphical Notes, 20, 45, b8, 95, 131, 180, 200, 288, 308, 337, 359, 387, 434, 496, 520, 551, 646, 680, 697 ; Geography on the Continent, 46 ; Geogaphical Society of Paris, 131, 200, 496, 521 ; German Geographical Journal-, 228 ; Deutsche geographische Blatter, 308, 697 ; the Progres; of Geographical Teaching, 337 ; a " Universal Geography," 378 ; the Congress of Commercial Geography at Pari:^, 387 ; American Geographical Society's Bulletin, 434 ; Italian Geographical Society, 521 ; Geographical Magazine, 521 ; Geographical Society, see Royal Geology: Geological Society, 56, 84, 187, 243, 271, 350; Geo- logists' Association, 136, 373, 424 ; the International Geological Congress, 148 ; Cataclysmic Theories of Geolo- gical Climate, James Croll, F.R.S., 187 ; of Greece, 206 ; the Cost of the Geological Survey Publications, 235, 290, 476; Physical, Prof. S. Haughton, F.R.S., 266; the Geo- logical Institute of Vienna, 287 ; American Geological Surveys, Prof. A. Geikie, F.R.S., 315, 516 : " Geologic der Gegenwart," Bernhard von Cotta, 380 ; Geological Relations of the Atmosphere, Prof. T. Sterry Hunt, F.R.S., 475 ; the Fossils of the North- West Highlands, 470 ; Geological Sur- vey of Ireland, 476 ; Rev. M. A. Close on the Extent of Geological Time, 477 ; " Eribollia Mack.iyi," 477 ; Dr. von Cotta's " Geologic der Gegenwart," 380, 487 ; Prof. Hayden's Atlas of • Colorado, 516 : American Geological Surveys, Prof. J. W. Judd, F.R.S., 538; Superficial Geology of South-West Lancashire, C. E. De Ranee, 561 ; Geological Survey of the Yellowstone Geyser Regions, 647 ; Geological Climate and Geological Time ; Prof, Joseph Le Conte, 668 ; German Geological Society Meeting, 684 Geometry : J. B. Millar's Descriptive, 277 ; Dr. G. J. Allman on Greek, 291; in Modern Life, J. Scott Russell, 380; Congress of "Geometres" at Paris, 237 George's Bank and the Grand Bank, Fossiliferous Tertiary Rocks from the, A. E. Verrill, 620 Germany : the Telephone in, 23 ; Fischerei-Verein, 49 ; Prof. Helmholtzon Academic Liberty in German Universities, 50, 78 ; Scientific Bibliography of, 77, 134, 207, 503, 600 ; Comparative Value of Fisheries, 206 ; Geographical Journals, 228 ; Plague of Grasshoppers in, 291 ; German Naturalists' and Phy- sicians' Meeting, 316, 435, 552 ; Addresses and Papers, 576 ; German Anthropological Society, 373 ; German African Society, 387; Apiculture in, 601 ; Deposits of Salt in, 601 ; German Geological Society Meeting, 684 Germ -Layers, the Primary, and the Origin of the Male and Female Reproductive Elements, 386 Gernez (M.D.), on Supersaturated Solutions of Salt'-, 318 Geyser Regions of the Yellowstone, Survey of, 647 Giddiness, 669 GiHard Balloon, 132, 262, 318, 345, 371, 393, 435, 534, 577, 705 Gill (Capt. W. J.), on the Border Thibet, 288 Glacial Period, the Distribution of Ice during the, T. F. Jamie- son, 187 Glacial Phenomena of the Long Island or Outer Hebrides, Dr. James Geikie, F.R.S., 187 Glaciers of the Western Himalayas, 263 Gladstone (Right Hon, W. E., M.P.) and the Homeric Expre ,- sions for Colours, Dr. Wiljiam Pole, P'.R.S., 676, 700 Glaisher (J. W. L.), Report of the B. A. Committee on Mathe- matical Tables, 505 Glasgow, Report of Industrial Museum, 159 Glass, Prof. Peligot on the Composition of Ancient, 182 Glass, Toughened, Caution against, 653 " Glossary of Biological, Anatomical, and Physiological For;zs," Thomas Dunman, 614 Glucinum, on some Double Salts of. Prof. E. Reynolds, 473 "Gold," Streeter's, 115 Gold Workings in French Guiana, 698 Gonidia, the Lichen Gonidia Question, Marcus M. Hartog, 3c 2 Goodrich (Commander), Old Map of Africa, 617 Gordon (J. E. H.), a Simpler Form of the Phoneidoscope, 383 Gottingen : Earthquake at, 105 ; Royal Academy of Sciences, 352, 712 ; Meeting of the German Geological Society, 684 Gout, Sarracoiia purpurea for, 133 Grand Bank and George's Bank, Fossilifercus Tertiary Roc' s from the, A, E. Verrill, 620 Nature, Nov. 2i, 1878] INDEX \'l Grapes : Chemical Changes taking place during the Ripening of, 336 ; Ripening of, after Removal from the Vine, 337 Graphic Formulae, on a Simplification of, Oliver J. Lodge, 472 Grass, English, for Paper Making, 682 Grasses of Mexico, 534 ; of New Zealand, 534 Grasshoppers in Germany during 1873, 291 ; in Costa Rica, 344 Gray (Andrew), and Thomas Gray on the Tasimeter and Magnetisation, 329 Gray (Prof. Asa), his "Flora of North America," 181 ; Synop- tical Flora of North America, Sir J. D. Hooker, F.R.S., 325 Gray (Thomas), " Under the Red Ensign," 380 Great Britain, Fossil Flora of, Prof. W. C. Williamson, F.R.S., 35 "Great Frozen Sea, the," Capt. A. H. Markham, 201 Greece, Austrian Geological Work in, 206 Greek Geometry, Dr. G. J. AUmann on, 291 Greenland, Exploration of from the West Coast, 697 Greenland Eskimo, A. Bordier, 16, 169 Greenow (Edward), New Lunar Crater, 220 Greenwell (W.), and Prof. RoUeston's "British Barrows," Prof. Boyd Dawkins, F.R.S., 429 Greenwich Observatory, Annual Report, 183 Griffith (Sir Richard), Obituary Notice of. Prof. E. PIuU, F.R.S., 627 Groot (Hugo de), 300th Anniversary of, 49 Grosvenor Gallery, open on Sundays, 372 Groth's Zeitschrift fiir Crystallographie, 106 Grouse, a White, Sir J. Fayrer, F.R.S., 518 Grubb (Thomas, F.R.S.), Obituary Notice of, 570 Guachos in Paris, 373 Guano, Discovery of, near Oizowo, 106 Guano Islands near Australia, 1 59 Guano in Texas, 344 Guiana, French, Gold in, 698 Gulf of Mexico, Deep-Sea Dredgings off the, 198, 357 ; Currents of the, 359 Gulf Stream, the Hydroids of the, Dr. G. J. Allmann, F.R.S., 326 Gulf- Weed, Mary P. Merrifield, 708 Gulls and Terns, Haward Saunders on, 83 Gylden (Prof.), on the Mean Parallax of a Star of First Magni- tude, 669 Gyno-dicecious Plants, Thomas Whitelegge, 588 Haarlem Society of Science, Award of Medal to Prof. S. New- comb, 132 Haeckel (Prof.), on the Doctrine of Evolution, 509 Halberstadt, Fata Morgana at, 466 Hall (Marshall), the Jura, 221 Halle, University of. New Buildings, 484 Hambiu-g Geographical Society, 46 Harbour Dredging in Japan, 600 Hardman (Edward T.), the Influence of Strike on the Physical Features of Ireland, 506 ; on Hullite, a Mineral from Carn- money Hill, Co. Antrim, 507 Ilarkness (Robert, F.R.S.), Obituary Notice of, 628 Harley (R., F.R.S. ), the Stanhope "Demonstrator" or Logical Machine, 506 Harmonic Engine, Edison's, 674 Harrison (Henry), Proposed Landscapes of the Moon, 182 Harrison (J. Park), Description of a Male Skeleton found at Cissbury, 215 Hartog (Marcus M.), the Lichen Gonidia Question, 302 Hartt (Prof. C. F.), Obituary Notice of, 174 Harvey Tercentenary, 145; Prof. Huxley's Speech at, 146; the Memorial Fund, 238 Haughton (Prof. S., F.R.S.), Physical Geology, 266 Hawaii, " Mikrographie der Glasbasalte von Hawaii: petro- grapliische Untersuchung," 248 Hayden (Dr. F. V.), United States Surveys, 316; Honours Conferred on, 343 ; Geological and Geographical Atlas of Colorado, Prof. A. Geikie, F.R.S., 516 Hearing of Insects, A. Simson, 540 ; Dr. W. L. Dudley, 568 Heat, Report on the Determination of the Mechanical Equivalent of, 440 Heat Theory, Cosmical Results of the Modem, J, Loschmidt, 184 Heat- Energy, on the Availability of Normal Temperature, S. Tolver Preston, 92 Heath Plant in America, 682 Heath's Expedition to Angola, 697 Hebrides, the Glacial Phenomena of the Long Island or Outer Hebrides, Dr. James Geikie, F.R.S., 187 Hekla, Moimt, on an Ascent of, and the Eruption of February 27, 1878, G. F. Rodwell, 596 ; the Height and Shape of, G. F. Rodwell, 641 Helmholtz (Prof., F.R.S.), on Academic Liberty in German Universities, 50, 78 ; his Vowel Theory and the Phonograph, Chas. R. Cross, 93 Helvetia, Society of Naturalists of, 321 Hemipterous Fauna of St. Helena, 135 Hemsley (W. B.), Diagnoses Plantarum Novarum vel Minus Cognitarum Mexicanarum et Centrali-Americanarum, 466 Hemsworth, New Coalfield near, 394 "Henfrey's Botany," A. W. Bennet, 217, 278 Henry (Prof. Joseph, LL.D.), Death of, 75 ; Funeral of, 104 ; Obituary Notice of, 143 Hereditary Transmission, Edmund Watt, 94 ; G. S. Watson, 116 "Herefordshire Pomona," 706 "Hermetically Sealed," 66 Herschel (Prof. A. S.), the Virial in Thermodynamics, 39, 142 ; Measuring Scales for Pocket Spectroscopes, 300 Hewitson (Wm. C), Obituary Notice of, 196 Hicks (Dr. Henry), on some New Pre- Cambrian Areas in Wales, 477 Highbury, Microscopical Society at, 631 Highlands, the Fossils of the North- West, 470 ' H^ll (S. h-\, Indian Rainfall, 193 ; Cyclones and the Winter Gales of Europe, 616 Himalayas, Glaciers of the Western, 263 Hind (J. R,, F.R.S.), " Newcomb's Astronomy," 7; Stellar Objects seen during the Eclipse of 1869, 663 Hissar and Amu-daria, Exploration of, 496 Hoeffer (M. Ferdinand), Death of, 76 Hpek (P. P. C), the Zoological Record, 569 Hoffmeyer (Capt.), on Atmospheric Pressure over the North Atlantic, &c., 680 Hofmann (Prof.), Illness of, 262 ; a New Camera Lucida, 312 Holland, see Dutch Holmes (E. M.), "Botanical Note- Book," 299 Homer, Colour Blindness in Relation to the Homeric Expres- sions for Colour, Dr. William Pole, F.R.S., 676, 700 Hong Kong, "Afforestation" of, 238 Hooker (Sir J. D,, P.R.S.), Botany in America, 325 Hopkins, Johns, University, Baltimore, 635 ; the Chemical Laboratory, 181 Horck (Dr. van der). Scientific Expedition, 359 Houston (Edwin J.) and E, Thomson, the 'I'elephone Relay or Repeater, 194 Howorth (H. H.), the Spread of the Slavs, 479 ; the Extinction of the Mammoth in Siberia, 483 Hubbard (G.), Physical Science for Artists, 278 Huddlestone (W. H.), the Coralline Oolites of Yorkshire, 136 Hudson (W. H. H.), Euclid, L, IL, 641 ; Algebra, 641 Hughes (Prof. D. E. ), Microphone, 57 ; Physical Action of the Microphone, 239 ; Edison's Microphone and the Telephone, 277 Hull (Prof. E., F.R.S.), Oiituary Notice of Sir Richard Griffith, 627; "The Physical Geology and Geography of Ireland," Prof. Arch. Geikie, F.R.S., 354 j the Progress of the Geologi- cal Survey of Ireland, 476 Hullite, a Mineral from Carnmoney Hill, Co. Antrim, Edward T. Hardman, 507 Hulme (F. E.), P'amiliar Wild Flowers, li Hutton Collection of Fossil Plants, Prof, Lebour's Catalogue of, 632 Humboldt (Alex, von). Colossal Statue of, 576 Humboldts, Monunreats to the, 393 Humming of Insects, 536 Humphry (Piof. G. M., F.R.S.), the Limbs, 427 Hiiningen, the Piscicultural Establishment, 504 Hungary, Natural Science in, for the Last Ten Years, 5S2 Hunt (Prof. T. Sterry, F.R.S.), the International Geological Congress, 148 ; the Origin and Succession of the Crystalline Rocks, 443 ; the Geological Relations of the Atmosphere, 475 Hutchinson (T. J.), Habits and Customs of Tribes of Tropical Aborigines, 479 Hutchinson (Dr. R. F.), Autophyllogeny, 541 Huxley (Prof. T. H., F.R.S.), Speech at the Harvey Tercen- tenary, 146 ; Address in the Department of Anthropology at the British Association, 44$; on the Use of Historical National A2 Xtl INDEX [Nalute, Nov. 21, 1878 Names and Scientific Terms, 479; on the Measuring of Crania, 481 " Huxley's Anatomy," Spengfel's German Translation of, 298 Hydrated Iron Ores, the Influences of Microscopic Vegetable Organism in the Production of some, 476 Hydrocarbons, Formation of, by the Action of Water on Man- ganese Iron Alloys containing Carbon, 337 Hydrogen : Peroxide of, E. Schone's Researches on, 318 ; Spontaneous Ignition of, by finely-divided Zinc, 679 Hydrogeological Survey of England, Joseph Lucas, 494 Hydroids of the Gulf Stream, Dr. G. J. Allman, F.R.S., 326 Hydro-Incubation, 542 ; the Tournament of Hydro-Incubators, 629 " Hydrostatics and Pneumatics," Philip Magnus, 693 Hygiene : Societe Fran9aise d'Hygiene, 424 ; the Congress of, at Paris, 504 Hyperion, the Saturnian Satellite, 426, 669 Hypnotism, Geo. J. Romanes, 492 Iceland, Fall of Volcanic Ash from; 199 Immersion Paraboloid, Dr. J. Edmunds, 278 ; John Mayall, Incubators, the Tournament of, 629 Indexes, a Subject-Index to Scientific Periodical Literature, 251, 279 ; " What is an Index ?" 632 India : the Great Trigonometrical Survey of, 180 ; Indian Rain- fall, S. A. Hill, 193 ; Meteorology of, in 1876, 199; Farming in, 219 ; the Size of the Indian Tiger, Sir J. Fayrer, F.R.S., 219; new Geological Map of, 475; Ethnological Objects from, 478 ; Indian Elephants, 552 ; Indian Building Timber, 317 ; Col. R. Benson, 569 ; Stanford's Map of Indian and Afghan Frontiers, 647 Indians, the Tribe of Nez Perces, 632 Indigo, Synthetic Preparation of, 251 Inductive Metrology, W. M. Flinders Petrie, no Industrial Chemistry, Pay en's, 218 Inflorescence of Senebiera didymOf Vtof. Alex. Dickson, 508 Ingleby (Dr. C. M.), the SeaSerpent Explained, 541 Innspruck, Earihquake at, 466 Insects : Corroborative of the Nativity of Certain Plants, Dr. Buchanan White, 278 ; Smell and Hearing in. Consul E. L. Layard, 301 ; the Humming of, 536 ; the Hearing of, Alfred Simjon, 540 ; Dr. W. L. l3udley, 568 ; the Microphone and the Hearing of, 652 Inside Out, C. J. Munro, 116 Institution of Civil Engineers, 49, 56, in, 136, 244 Insulating Stand, a New, Prof. M. E. Mascart, 144 Interior of the Earth, Sir George B. Airy, F.R.S., 41 Intra-Mercurial Planet, 495, 520, 552, 569 ; Sir G. B. Airy, P'.R.S., 380, 495 ; Prof. J. C. Watson, 433, 495^ 616;- Lewis Swift, 539 Invariants, Dr. Wright's Tract on, 6S3 Ireland : Extinct and Recent Irish Mammals, Prof. A. Leith Adams, 141 ; Prof. Boyd Dawkins, 169 ; Hull's Geology and Geography of. Prof. Arch. Geikie, F.R.S., 354; the Geo- logical Survey of, 476 ; Prehistoric Monuments of, 478 ; 1* lint Factories in, 478 ; Recent Additions to Irish Lepidoptera, 483 ; the Rainfall of, G. J. Symons, 484 ; the Influence of Strike on the Physical Features of, Edward T. Hardiivan, 506 Iron and Mercury, Specific Heats of, 679 Iron and Steel Institute at Paris, 502, 553, 574- Island Volcano, Metals on, 238 Jsobaric Charts of the Globe, Dr. Wojeikof, 288 Isoetes echinospora. Exhibition of Plants of, 508 Isomeric Bodies, Heat Evolved in the Formation of, 336 Isomorphous Salts, Change of Indices in- Mixtures of, 336 Isthmus of Darien, Proposed Canal Across, 238 Italian Geographical Society, 521 Ithaca, the Ancient "Capital of, 590. Jablochkoff Electric Light; 6S2"; itf Paris; 317 ; Spectrum of, E. Walker, 384 Jacobsen (J. C), his Brewery Laboratory, 503 Jiihresbericht der Chemie, 105 Jamieson (James), the Respiration of Plants, 539 Jamieson (T. F.)^ the Distribution of Ice Diiring the Glaeiial . Period, 187 Janssen's New Method of Solar Photography, H. F. Blanford, 643 Japan : Kerosene Oil in, 23 ; Manufacture of Boots in, 49 ; Copper Smelting in, 105 ; the Forests of, 181 ; Earthquakes in, 182 ; Telegraphy in, 182 ; Japanese Astronomers in Europe, 205; Proposed Harbour and Canal in, 228; Calendar of the Tokio College of Engineering, 263 ; Permanent Exhi- bition in, 292 ; the Timber of, 317 ; Railways in, 344 ; Engi- neering Works in, 344 ; Records of Earthquakes in, 373 ; Brewing in, R. W. Atkinson, 521 ; the Flora of, 534; Harbour, Dredging in, 6co ; Japanese Black Teas, 705 Java, Bees in, 238 • Jeffi-eys (J. G., F.R.S.), the Norwegian Arctic Expedition, 568 Jena, the Observatory of, 392 Jenkin (Prof. Fleeming, F.R.S.), and Prof. J. A. Ewing, the Phonograph and Vowel Theories, 167 ; on the Phonograph and Vowel Sounds, 340, 394, 454 Jevons (Prof. Stanley, F.R.S.), the Pedetic Action of Soap, 440 ; on the Periodicity of Crises, 483 Johns Hopkins University, Baltimore, 63S ; Summer Labo- tory, 181 Johnston (Keith), Expedition to Lake Nyassa, 646 Jones (Capt. W. A.), American Exploration, 667 Jones (Rev. Frank), Life of Sir Martin Frobisher, il Jordan (Prof. D. S.), Vertebrates of the Northern United States, 167 Joule (R. St. J. B.), oii a Remarkable Flash of Lightning, 260 Joule (Dr. Prescott), Civil Pension to, 316 Journal de Physique, 214, 350, 560, 687 Journal of Physiology, 377 Journal of the Cincinnati Society of Natural History, 636 Joiu-nal of the Franklin Institute, 636 Journal of the Russian Chemical and Physical Societies, 400 Judd (Prof. J. W., F.R.S.), American Geological Surveys, 538 Julius (V. A.), the Microphone as a Receiver, 642 Jura, the, Marshall Hall, 221 Karat ej in, the District of, 289 Kekule (Prof. Aug.), the Scientific Aims and Achievements of Chemistry, 210 Keller (Dr. Ferdinand), Lake Dwellings of Switzerland, 664 Kempe (A. B.), a Kinematic Problem, 149 Kent (W. Saville), the Origin and Distribution of Organic Colour, 523 Kentish Boring Exploration, 469 Kent's Cavern, the Exploration of, 468 Kentucky, Remarkable Cave in, 575 Kepler and Anthelm's "Temporary Stars," 281 Kepler's Manuscripts and Relics, 20 Kerosene Oil in Japan, 23 Kew Gardens: Botanical Museum opened on Sundays, 194, 220; Report, 370 Kiel, Meeting of German Anthropologists, 466 Kiepert's Map of Cyprus, 520 Kinematic Problem, A. B. Kempe, 149 Kinetic ITieory of Gases, the View of the Propagation of Sound demanded by the Acceptance of, S. Tolver Preston, 253 King (Clarence), American Geological Surveys, 538 King (Prof. W.), the Crystalline Rocks of Donegal, 478 Kirchhoff" (Prof.), on Submarine Cables, 106 Kitchener (Lieut.)-, on a Survey of Galilee, 483 ; his Survey of Palestine, 521 ; appointed to survey Cyprus, 521 Klenke's Work on the Adulteration of Food, 106 Knapton (H. P.), Taunton College School, 357 Knowles (W. J.), Flint Factories at Port Stewart, &c., 478 Kola Peninsula, Exploration of, 697 Konigsberg, Schriften der physikalisch-okonomischen Geseil- schaft, 24S Kosmos, 399, 584 Krebs (Dr. G.), on the Conservation of Energy, 706 Krefft (Gerard) and the Trustees of the Australian Museum, 575 Krukenberg's " Mikrographie der Glasbasalte von Hawaii: petrographische Untersuchung," 248 Kriimmel (Dr. Otto), the Rainfall of Europe, 287 Kruttschnitt (Julius), Rayons de Crepuscule, 540 Kurz (S.), Forest Flora of British Burmah, 517 Laboratory, a School, W. A. Shenstone, 347 Liaboratory Notes, Prof. J. G. McKendrick, 240 Nature^ NoZ'. 2i, 187S] IXt>EA xni Labyrinthodont Amphibia at Jarrow Colliery, Kilkenny, 475 Labyrinthodont from the Trias, 48 Ladd (W.), Edmunds' Electrical Phonoscope, §06; 6n Byrne's Battery, 506 Lady Franklin's Sound, Capt. Tyson's Jotirney to, 521, ^51 Lake, a Poisonous Australian, Geo. Francis, n " Lake-Dwellings of Switzerland," Dr". Ferdinand Keller, 664 Lake-Dwellings in Bavaria, 601 Lamprey, the Fertilisation of Eggs of the, 227 Lancashire, the Superficial Geology of South- West, C. E. De Ranee, 56 f Lancet, the, on State Aid to Science, 62^ Landrails, Charles Dixon, 116 Lang (R. Hamilton), Cyprus, 693 Langethal (Prof., C.E.), Death of, 435 Lankester ^Prof. E. Ray, F.R.S.), Balfoiu^s " Elasmobi'anch Fishes," 113; on the Endowment of Research, 610 Laplace, Portrait of, 575 Lapp Languajje, Dictionary of, 238 "Lardner's Mechanics," 247 Laridas, Geographical Distribution of the, 83' Lawes (Rev. W. G.), Exploration of New Guinea, 289 Lawrence (E. J.), Remarkable Form of Lightning, 278 Layard (Consul E. L.), Smell and Hearing in Insects, 301 Lead and Thallium, Prof. H; E. Roscoe on the Spetific Gravity of the Vapours of the Chlorides of, 214 Lead, Chloride, and Bees'-Wax, Electrical Properties of, 294 Leaves of Trees, the Falling of, 512 Leaves, the Physical Functions of, 672 Lebour (G. A.), " Illustrations of Fossil Plants," 35 ; "Nomen- clator Stratigraphicus," 344 Le Conte (Prof. Joseph), Geological Climate and Gfcological Time, 668 Lecky (Robert J.), Physical Sdience fof Artists, 116 Lecture Experiments, Francis E. Nipher, 94; Prof. McKen- drick, 240 Lee (John Edward), Translation of Dr. Keller's Lake Dwellings of Switzerland, 664 Leeds, the Yorkshire College of Science, 241, 350 ; Calendar, 635 Lees (F. Arnold) and J. Davis' "West Yorkshire," 276 Lens, Carl Zeiss's "Oil Immer-sion," 240 Lepidoptera, how they Escape from their Cocoons, 226 Lepidoptera, Irish, Recent Additions to, 483 Lepper (C. H.), Attempted Overland Journey to China, 599 Lesquereux (L.), Tertiary Ftora of North America, J. S. Gardner, 189 Lesseps (M.), Lectures on Africa, 237 Letts (Prof, E. A.), on the Thetines, 474" Leverrier, Portrait of, 575 Lewes, Excavations at Mount Caburn, Lewis (A. L.), on the Evils arising from the Use of Historical National Names and Scientific Terms, 479 Ley (Clement), Weather Maps, 287 Leymarie (M.), Death of, 652 " Leyton Observations," the, 225 Lichen Gonidia Question, Marcus M. Hartog, 302" Liebig Monument, 503 Liebreich (Dr.), "School Life in its Influence on Sight and Figure," 534 Light : Velocity of, Albert A. Michelson, 195 ; the Influence of, on Bioplasm, 398 Lightning : Phenomenon, H. J. Staples, 67 ; a New Protection from, 133 ; Remarkable Flashes of, R. St. J. B. Joule, 260; E. J. Lawrence, 278; B. Woodd Smith, 302; Effect of, on an Aspen Tree, 533 ; Compound Lightning Flashes, E. H. Pringle, 587 Lightning Conductors, Richard Anderson, 554 Lim Fjord, New Bridge Acro.-s, 5^55 Limbs, the Genesis of, St. George Mivart, F.R.S., 282, 309, 331 Limbs, the. Prof. G. M. Humphry, F.R.S., 427 " Limburg," Discovery of Prehistoric Remains near the, 555 Lindley and Hutton's IllastratiDns of Fossil Plants, 35 Link- Work, Prof. Kennedy on, 83 Links of the Animal World, Prof. Boyd Dawkins,^ F.R.S., 537 Linna:an Society : 83, 1 10, 294 ; Foreign Members, 75 ; Annual Meeting, 270 Linnaeus : the Statue to, 48 ; his " Systema Naturae," 419 Liquefaction of Gases, M. de Cailietet's Apparatus for, 46 Lisbon, Earthquake in, 182 Liskeardite, a New Mineral, 426 Lissajous' Figures, Improved Method for Projecting, on the Screen, 24 Liveing and Dewar (Professors) on the Reversal of the Lines of Metallic Vapours, icg, 321 Liver, Action of Drugs on the. Prof. Wm. Rutherford, F.R.S., 268 Liverpool, Literary and Philosophical Society of, 105 Lloyd (F. G.), the Electro-Magnet a Receiving j elephone, 4SS Loch Fyne, Manganese Nodules in, J. Y. Buchanan, 628 Lockyer (J. Norman, F.R.S.), Physical Science for Artists, 29, 58, 87, 122, 154, 223; an Eclipse Spectroscope, 224; his Observation of the Solar Eclipse, 353, 394, 401, 457 Locomotive, Super-heated Water for, 106 Lodge (Oliver J.), on a Simplification of Graphic Formula?, 472 " Loess," the. Formations of the Danube in Moravia, 207 Logical Machine, the Stanhope "Demonstrator," 506 Lommer(E.), on Fluorescence, 107 London, University of, 82 ; Supplemental Charter, 559 London Mathematical Society, see Mathematical London, the Geology of, 235 ; Geological Map of, 235 ; Geo- logy of the London Basin, 350 Longitude and Time, Latimer Clark, 40; Ca^f. J. P. Maclear, 66; Rev. S. J. Whitmee, 220 Loomis (Prof.), Winds in the United States, 198 ; on Storms, 288 Loschmidt (J.), Cosmical Results of the Modern' Heat Theory, 184 Low Temperatvu-es, Use of Methyl Chloride for the Production of' 337 Lubbock (Sir John, F.R.S.), on the HaVts of Ants, 482 Lucas (Joseph), Hydrogeological Survey of England, 494 Lugger (Mr.), Exploration of the West Indies, 49 Luminous Meteors, B.A. Report on, 505 Lunar Crater, a New, 197, 220 Lunar Eclipse of August 12, 385 Lunar Rainbow, Secondary, W. J. Nobld, 67; R. Walker, 618 Lundy Island, the Climate of, 295 Lyall (Wm.), Albinism in Birds, 5^ Lyons Observatory, 553 Lyrje (a), Companion to, 434 McCarthy (John), Journey through China, 681 Macdonald (Dr. J. D., F.R.S.), on the Anatomy of the Organ of Hearing in Relation to the Discovery of th^ Principles of the Microphone and Magnophone, 285 McDonnell (Dr. R., F.R.S.), Address in the Department of Anatoifty and Physiology at the British Association, 445 McKendrick (Prof. J. G.), Laboratory Notes, 24O McLeod and Clarke on the Telephone, 1 1' •Maclay Coast, the Papuans of the, 387 Maclear (Capt. J. P. ), Time and Longitude, 66 Magnetic Declination, Diurnal Range of, at the Trevandrum Observatory, 25 ; Variations of the Diurnal Range of the, as Recorded at Prague Observatory, Prof. Balfom: Stewart, F.R.S., 242 Magnetic Observatory at Pavlovsk, 316 Magnetic Storm, May 14, 1878, Rev. S. J. Perry, F.R.S., 617 ; WiUiam Ellis, 641 ; W. H. Preece, 668 Magnetic Survey of Washington, 466 Magnetisation : the Influence of Stress on. Sir Wm. Thomson, F.R.S., 215 ; the Tasimeter and, Aiwirew and Thomas Gray, 329^ Magnetism, " La Revue Magnetique,'*^6i5 Magnetism and Electricity, Catalogue of Works on, 393 "Magnetism and Electricity," George Porter, 615 Magneto-Telephone, 392 Magnets : Floating, Sir William Thomson, F.R.S., 13 ; A. M. Mayer, 258 ; C. S. Pierce, 381 Magnophone, its Relatibn to the Organ of Hearin?, 285 Afagnas (Philip), "Hydrostatics and Pneumatics," 693 Main (Rev. Robert, F.R.S.), Obituary Notice of, 72 Malaguti (Faustinus J. M.), Obituary Notice of, 15 MaFay Peninsula, 68 Mallory Propeller, the, 465 Mammoth, the Epoch of the, G. James C. Southwell, 245 Mammoth in Siberia, the Extinction of, H. H. Howorth, 483 Man, Prof. Daniel Wilson on the Evolution of some Varieties of, 479 - ^ XIV INDEX {^Nature, Nov. 2i, i5 Manatee at Westminster Aquarium, ^38, 394 Manchester : Literary and Philosophical Society, 375, 428 ; Owens College University Scheme, 53 Manganese Nodules in Loch F}ne, J. Y. Buchanan, 628 Manganese Tetrachloride, 679 Mann (J.Nixon), Improved Method for Projecting Lissajou.' Figures on the Screen, 24 Maoris, Arrow Propulsion of the, 27 Maple, ReJ, Sexual Conditions in the, 387 Maps : Old Maps of Africa, 149, 617 ; some New Maps, 33S ; Map of France, 496 Markham (Capt. A. IL), " The Great Frozen Sea," 201 Marmot, Fossil Remains of the, 104 Mars : Occultation of, 67 ; the Satellites of, 618 Mascart (M. E.), a New Insulating Stand, 44 Maskelyne (Prof. N. S., F.R.S.), a New Mineral, 426 Mastodon, Discovery of the Incisor of, 373 Mathematics': Mathematical Society, 55, 83, 294, 651 ; Recent Mathematical Works, 247 ; American Journal of, 316, 484; Report of the British Association Committee on Mathematical Tables, 505 Mauritius Meteorological Report, 288 Maxwell (Prof. Clerk, F.R.S.), on Stresses in Rarefied Gases Arising from Inequalities of Temperatm'e, 54 ; the Tele- phone (Rede Lecture), 159 Maxwell (Gen. H. H.), Pozzolana Mortar and Pine Timber, 19 Mayer (Prof. A. M.), Floating Magnets, 258 ; on the Nature of Vibratory Motions, 571, 594, 648 Mayer (Dr. Robert von). Death of, 104 Measuring Scales for Pocket Spectroscopes, Prof. A. S. Herschel, 300 Mechanics : Crofton's Elements of Applied, 247 ; Lardner's Mechanics, 247 " Mechanical Chameleon," 47 Medical Faculties, the, 610 Mediterranean and Southern Hemisphere, the Tides of the, Capt. Evans, F.R.S., and Sir William Thomson, F. R.S., 670 Meehan (Thomas) Vaiying Experiences, 334 ; " Native Flowers and Ferns of the United States, 615 Megaphone, Edison's, 676 Meldrum (C.), Sun-Spots and Rainfall, 564 Melted and Solid Materials, the Relative Specific Gravities of, 397. 464 , ^ Memorie della Societa degli Spettroscopisti Italiani, 214 Mendeleeff (Prof.), Visit to Western Europe, 434 Menziesia ccerulea : Alex. Craig Christie, 66; G. C. Druce, n6 "Mercator," Memorial of, 496; Derivation of his Name, 588 Mercury : Transits of, 19 ; the Recent Transit of, 46, 130, 147 ; the Transit of, 186?, 179; Estimation of, 679 Mercury;, Specific Heats of, and Iron, 679 Merlin (C. L. W.), a Hunting Wasp, 311 Merrifield (Mary P.), Gulf- Weed, 708 Merriman (Mansfield), " Method of Le?st Squares," 299 Metal, Floating of Solid on Molten, W. J. Millar, 397, 464 Metallic Vapours, the Reversal of the Lines of. Professors Liveing and Dewar, 109, 321 Metals, the Physical Properties of, Dr. C. R. Alder Wright, 69 Meteorite, a, J. Harris Stone, 464 Meteorites, Prof. Nordenskjold on the Composition and Common Origin of Certain, 510 Meteorology: Mete; rological Notes, 198, 287, 335, 680; Meteorological Society, 83, 135, 295 ; Lectures, 423, 681 ; Scottish Meteorological Society, 262 ; Jerome J. CoUins on American Storm Warnings, 4, 31, 61 ; Dr. Woeikof on American Storm Warnings, 517; Cmrious Meteorological Phenomenon, 50; the Reduction of Meteorological Ob- servations, 83 ; Organisation of French, 96 ; Cosmic, J. Allan Broun, F.R.S. , 126, 151 ; French Congress of, 132; 423; the French Meteorological Service, 134; the Obser- vatory at Upsala, 157; the French Central Meteorological Bureau, 158, 372, 435, 601 ; of the Bombay Presidency in 1876, 199 ; Rainfall of Europe, 287 ; Prague Observations on the Wind, 287 ; Swedish Weather Maps, 287 ; Ley's Weather Maps, 287 ; Missouri Weather Service Report, 288 ; Mauri- tius Meteorological Report, 288 ; Prof. Loomis on Storms, 288; Dr. Woeikof's Isobaric Charts, 288; Catalogue of Works on, 346 ; the Climate of Cyprus, 335 : the Bulletin of the Paris Observatory, 393 ; French Meteorological Com- missions, 424 ; the Vaucluse Meteorological Commission, 435 ; Prof. Nipher's Magnetic Survey of Washington, 466 ; New Society at St. Petersburg, 503 ; French Meteorological Telegrams, 553 ; the United States Signal Service, 553 ; the Mont Ventoux Observatory, 553 ; in Chili, 600 ; Secchi's " Meteorologica Romano," 601 ; the Magnetic Storm of May 14, 1878, 617, 641; W. H. Preece, 668; the Farmers' Weather Indicator, 621, 630; Capt. Hoffmeyer on Atmo- spheric Pressure over the North Atlantic, &c., 680 ; Report of the Meteorological Institute of Prussia, 680 ; Dr. Hellmann's Observations on Cloud, 680; Observations of the Upper Currents of the Atmosphere, 680 ; Weather- Warning at the Paris Exhibition, 682 Meteors: 23, 77, 105, 170; the Meteor of May 12, 105, 142; the Meteor of June 7, 1878, 185 ; at Privat, Ardeche, 318 ; the Meteor Shower of Aquarids (July), 356, 384; the August, 385; in Hesse, 504; Report of the B.A. Com- mittee on Luminous Meteors, 505 ; Sydney Evershead on, 519; Meteor Shower of Andromedes I., W. F. Denning, 568 ; the Meteor of December 24, 1873, 570; in Germany on September 6, 575 ; at Montpelier, 575 ; near Cambridge, O. P. Fisher, 643 "Method of Least Squares," Mansfield Merriman, 299 Methyl Chloride, Use of, for the Production of Low Tempera- tures, 337 Metric System : the Paris Congress of Weights, Measures, and Coins, 504, 532 Metrology, Inductive, W. M. Flinders Petrie, no MeudoUj Proposed Observatory at, 157 Meux and Co.'s Artesian Well, 350 Mexico, Grasses of, 534 Mexico and Central America, Proposed New Work on the Botany of, 466 Meyer (Dr. A. B.), Earthquakes on the Philippines, 265 Meyer (Prof, Victor), his New Laboratory, 503 Miall (L. C), Anatomical Preparations for Museum and Clafs Purposes, 312 Michelson (Albert A.), Velocity of Light, 195 " Micrographie der Glasbasalte von Hawaii; petrographische Untersuchung," 248 Micrometer, a New, 688 Microphone, the : 20, 57, 323, 392 ; Dr. C. W. Siemens-, F.R.S., 129; G. M. Seabroke, 129; F. J. M. Page, 130; in Surgery, Sir Henry Thompson on, 157; James Blyth on, 172, 181; New Form of Microphone Receiving Instrument, W, J. Millar, 194 ; W. H. Preece on, 207 ; Prof. Hughes on the Physical Action of, 239 ; Prof. McKendrick on, 240 ; Prof. Hughes' Telephone and, 277 ; the Organ of Hearing iu Relation to Prof. Hughes' Microphone, 285 ; Sir William Thomson, F.R.S., 355 ; Prof. W. F. Barrett, 356 ; Sir Chas Wheatstone's Microphone, 356 ; Prof. Wm. Leroy Broun, 383 ; Gerald B. Francis, 383 ; in Indirect Circuit, 464 ; Thomas Rowney on, 519; and Earthquakes, 533; S. T. Barrett on, 540 ; as a Receiver, V. A. Julius, 642 ; and Insects, 652 Microscopy : Hints to Workers with the Microscope, 141, 195 ; New Invention for Showing Slides, 159; Microscopical So- ciety, see Royal ; Translation of Naegeli and Schwendener's " Das Mikroskop," 533 ; an American Microscopical Con- gress, 601 ; Microscopical Society at Highbury, 631 ; the Immersion Paraboloid, Dr. J. Edmunds, 278 ; John Mayall, jun., 331 Middleton (R. Morton), Sense of Fear in Chamseleons, 696 Midgley (James IL), Earth Pillars, 569 Midian : Capt. R. F. Burton's Exploration of, 76; the Tribe; of, Capt. R. F. Burton, 480 Midland Union of Natural History Societies, 158 "Mikroskop, Das," Naegeli and Schwendener's, Translation of, 533 Military Ballooning, H. Baden Pritchard, 491 Millar (J. B.), Elements of Descriptive Geometry, 277 Millar (W. J.), Transmission of Vocal and other Sounds by Wires, 12 ; New Form of Microphone Receiving Instrument, 194 ; Floating of Solid on Molten Metal, 397, 464 ; " Studies in Physical Science," 693 Miller (S. H.) and S. B. H. Skertchly, "The Fenland, Past and Present," 514 Miller's Chemistry, 614 Mimas, the Saturnian Satellite, 520, 696 Mimicry in Birds, William E. Armit, 643 Minchin (G. M.), " A Treatise on Statics," 247 r Nature, Nov. 21, 1878] INDEX XV Mineral, a New, Prof. N. S. Maskehme, F.R.S., 426 Mineral Oil or Paraffin Wax, the Estimation of, when mixed with other Oils or Fat, Wm. Thomson, 473 Mineral Spring at Suhl, 706 Mineralogical Society, 238, 291 Minerals, on a New Method of Studying the Optical Characters of, H. C. Sorby, F.R.S., 684 Minor Planets, 307 Mira Ceti, 180 Missouri Weather Service, Report of, 288 Mivart (St. George, F.R.S.), the Genesis of Limb?, 282, 309, 331 Mobius (Prof.), the Movements of Flying-fish through the Air, 373 Mohn (Prof. H.), Fall of Volcanic Ash from Iceland, 199 ; the Norwegian North Atlantic Expedition, 222, 368, 425, 589 Moncel (Comte du) on the Photograph, 553, 630; " Le Tele- phone, le Microphone, et le Phonographe," 698 Monkeys : Fear of Snakes amongst, 227 ; Dental OperaliDn on a Monl Preston (S. Tolver), on the Availability of Normal-Temperature Heat-Energy, 92 ; on the View of the Propagation of Sound Demanded by the Acceptance of the Kinetic Theory of Gases 253 Preventive Medicine in Relation to Public Health, Dr. A Car- penter, 248 Primates, Fear of Snakes in the, 227 Prime--, Forms of. Exceptions to, 344 Pringle (E. H.), Physical Science for Artists, 356 ; Brehm's " Ihierleben," 518; the Sea-Serpent Explained, ^ig; Com- pound Lightning Flashes, 587 Pritchard (H. Baden), Military BallooninT, 491 Prjvalsky's Exploration of Thibet, 496 Procter (Henry R.), the Aurora Observations of the Austro- Hungarian Arctic Expedition 1872-74, by Carl Weyprecht, Proctor (R. A.), the Cycloid and Cycloidal Curves, ^55 Protectorate, our New (Cyprus), 302 Proterogynous Lichogamy, on the Association of an Incon- spicuous Corolla with, in Insect-Fertiljsd Flowers, 508 r'stlophytum monense, 555 Pulkowa Library Cataloge, 20 Pulkowa Observatory, New Refractor for, 502 ; Observations of the, 688 Puy-de-D6me, Nocturnal Variations of Temperature at, 608 Pyridine Series, Investigations on the, Dr. W. Ramsay, 473 Quartz ; Influence of Temperatme on the Rotatory Power of, Quetelet (Ernest), Obituary Notice of, 551 Radau (M. R.), Les Radiations chimiques du Soleil, 63 Radiolarians, the Supposed, and Diatomacea; of the Coal- Measures, Prof. W.-C. Williamson, F.R.S., 508 Railway Brakes, 471 Rainbow, Quadruple: Henry P. Dowling, 142; Multiple, 170; on Certain Phenomena accompanying. Prof. Silvanus P. Thompson, 441 ; an Unusual, G. M. Whipple, 696 Rainfall : of India, S. A. Hill, 193 ; of Europe, 287 ; of Brazil and Sun-Spots, Orville A. Derby, 384; of Ireland, G. J. Symons, 484; and Sun-Spots, C. Meldrum, F.R.S., 564 Ramsay (A.), a Subject Index to Scientific Periodical Literature, 279 . . , Ramsay ( Dr. W. ), Investigations in the Pyridine Series, 473 ; some of the Derivatives of Furfurol, 474 Ranee (C. E. De), the National Water Supply, 73 ; the Super- ficial Geology of South-West Lancashire, Prof. W. Boyd- Dawkins, F.K.S., 561 Rarefied Gases, on Stresses in, arising from Inequalities of Tem- perature, Prof. Clerk-Maxwell, F.R.S., 54 Rayleigh (Lord, F.R.S.), on Uniformity in the Rate of Rota- tion of an Axle, 1 1 1 ; the Explanation of Certain Acoustical Phenomena, 319 Rayons de Crepuscule, F. Pollock, 249 ; Rev. R. Abbay, 329 ; E. H. Pringle, 356; Julias Kruttschnitt, 540; H. S. Car- hart, 540 Reale Istituto Lombardo di Scienze e Lettcre, 186, 350, 400, 636, 688 Reclus (Elisee), 393 Rede Lecture, Prof. Clerk-Maxwell's, 159 Reed (E. J., C. B., F.R.S.), "White's Naval Architecture," 137 Reflector, Three-Foot, Lord Rosse on an Equatorial Mounting for a, 506 Relationships, Classification of Primitive, 135 Renard (Capt.), Improvements in Balloons, 133 Rendiconto delle bessioni deU' Accademia delle Scienze dell' Istituto di Bologna, 428 Reproductive Elements, the Primary Germ-Layers and the Origin of the Male and Female, 386 Research, the Endowment of. Prof. E. Ray Lankester on, 610; the Lancet on State Aid to Science, 629 Resonators, Brass Wind Instruments as, 271 Respiration of Plants, James Jamieson, 539 Resting Spores, Dr. E. Perceval Wright, 173 Retrospect and Prospect, I Reyer (Dr. Ed.), Beitrag zur Fysik der Eruptionen und der Eruptir-gesteine, 91 ; " Vulcanologische Studien," 487 Rheostat, Edison's New Carbon, 674 Rheostatic Machine, Gaston Plante, 45 Ridout (R. H.), an Experimental Investigation of the Structure of Fluid Colunms which are Affected by Sound, 604 Rio Grande do Sul, Proposed Railway from, to Uruguay, 133 Rivers and Streams, the Conservancy of, 661 ; Edward Easton, C.E., 452 Roberts (E.), Self-Acting Tide- Calculating Machine, 75 Roberts (Isaac), on the Filtration of Sea- Water through Triassic Sandstone, 475 Robertson (David, Jun.), White Swallows, 618 Robinson (Prof. 1.), New Work on Ferns, 555 Robinson (Dr. T^ R.), the Determination ot the Constants of the Cup Anemometer, 82 Robinson (W.), " Parks and Gardens of Paris," 562 Rodier (E.), Solar Halo, 13 Rodvvell (G. F.), Proposed Observatory on Mount Etna, 587 ; on an Ascent of Mount Hekla and the Eruption of February 27, 1878, 596; the Height and Shape of Mount Hekla, 641 Rohl'fs (Dr.Gerhard), Expedition to Africa, 521, 601 Rokitansky (Baron Karl von), Obituary Notice of, 371 XVIU INDEX \Naturt, Nd'. 21, 1878 Romanes (Geo. J.), Hypnotism, 492 ; Animal Intelligence, 642 Rome, Accademia dei Lincei, 28, 216, 244, 376, 687; Geogra- phical Society of, 46 ; the University of, 293 Ronalds (Sir Francis, F.R.S,), Bibliography of Works on Electricity and Magnetism, 393 Roromiko, a New Remedy for Diarrhoea, 49 Roscoe (Prof. II, E., F.R.S. ), Specific Gravity of the Vapours of the Chlorides of Thallium and Lead, 214 Ross (W. A.), Alumina, 279 Rosse (Lord), Description of an Equatorial Mounting for a Three-Foot Reflector, 506 Rossi (Prof. M. S. de), on an Earthquake at Rocca di Papo, 533 Rotating Book- Case, 15 Rotifers, &c., how to Observe, 141, 196 '• Rousseau, Centenary of his Death, 345 .Routh (E. J„ F.K.S.), "Dynamics of a System of Rigid Bodies," 247 Rowney (Thomas), the Microphone, 519 Royal Archrcological Institute, 393 Royal Astronomical Society, 55 Royal Botanic Society, 425 Royal Geographical Society, Anniversary Meeting, 131 ; African Exploration Fund, 131 Royal Institution of Great Britain, 48 Royal Irish Academy, Medals of, 158 Royal Microscopical Society, 84, 1 1 1, 295, 660 Royal School of Mines, 399 Royal Society, 25, 54, 82, 109, 135, 186, 214, 242, 269, 293, 321 ; Conversazione, 47 ; Portraits of the Fellows, 575 Russell (J. Scott), Geometry in Modern Life, 380 Russia : St. Petersburg: Chemical and Physical Societies, 53, 350, 4C0 : Geographical Society, 95 ; Russian Chemical Society, 106 ; Stone Implements in, 264 ; Proposed Change of Chronology in, 532 ; see also St. Petersburg, Moscow, &c, Rutherford (Prof, Wir., F.R.S.), Action of Dnigs on the Liver, 268 Rutherfurd's Photograph of Solar Spectrum, 271 Rye (E. C), the Zoological Record, 615 Sabine (Robert), Motions Produced by Dilute Acids on feme Amalgam Surfaces, 441 Saccharose, 336 Sachs (Dr.). Fatal Accident to, 504 Sachsenhausen, Phylloxera at, 505 Sacrum : Lawson Tait on the Occurrence of a Sacral Dimple, 481 ; Aberrant Sacrum connected wiih the Oblique Pelvis, 483 Sahara, Dr. Chavanne's Work on the, 360 St, Gothard Tunnel, 22 St. Helena, Dr. Buchanan White on the Hemipterous Fauna of, 13s St. Petersburg Chemical and Physical Societies, 53, 350 ; Bulletin de I'Academie des Sciences, 186 ; Proposed Geological Institute, 435 ; New Meteorological Society at, 503 St. Vincent, the Island of, Cocoa-Nut Palms on, 706 Salamander, the Artificial Transformation of the Alpine, G. T, Bettany, 108 Salmon, Introduction of, in Germany, 49 Salmon and Trout Fungus Disease, 48 Sal pa, the Male of, 307 Salt, Thomas Ward's Paper on, 555 ; Deposits of, in Germany, 6or, 705 Salt Lake City, Prof, T, E. Thorpe, F.R.S., at, 502 Salt Water, Preservation of Coffee in, 344 Salts, Supersaturated Solutions of, 318 Samojedes and Ostiacs, Collection of Articles used by, 48 Sandeberg (Lieut.), Exploration of the Kola Peninsula, 697 Sanderson (Dr. Burdon, F.R.S.), Resignation of Professorfhip at the Brown Institution, 290 ; and F. J. M. Page on the Rhythmical and Excitatory Motions of the Ventricle of the Heart of the Fi-og, 293 Sanford (W. A.), Meteor, 170 Sanitai7 Institute of Great Britain, 49, 158, 263; Anniversary Meeting, 236 ; Exhibition of, 503 ; at Stafford, 631 Sap in Trees, Causes of the Ascent of, 213 Sargasso Weed, 708 Sars (Prof. G. O.), " MoUusca Regionis Arcticae Norvegige," 568 . Saturn's Satellites, 307 ; Hyperion, 426, 669 ; Mimas, 520, 696 ; Titan, 619 Saunders (Howard), the Geographical Distribution of Gulls and Tern-, 83 Saurian, t New Fossil, 28 Saurians from Colorado, 476 Savage (Lieut. G. R. R.), Experiments on Long Distance Tele- phones, 77 ; the Telephone, 488 Sawyer (John), Automatic Arithmetic, 327 Sayce (Rev. A. H), Ethnology of North- West America, 165 Scandinavia, Aurora Borealis in, 632 Scheibler's Tuning-Forks, A. Cavaille-Coll on, 381 Schliemann (Dr.), his Excavations, 373 ; on the Ancient Capital of Ithaca, 590 Schmeltz (Dr. J. D. E), the Eskimo at Paris, 169 Schmidt's Charte der Gebirge des Mondcs, 434, 501 Schone (E.), Researches on Peroxide of Ilydrogen, 318 ' School Laboratory, W. A, Shenstone, 347 Schools, Science in, 273, 279 ; the Times on, 434 Schriften der physikalisch-okonomischen Gesellschaft zu Konigr- berg, 242 Schuster (Dr, A.), tbe Spectrum of Oxygen, 269 Schwann (Theodore), 297 Schweinfurth (Dr. George), Return to Cairo, 308 Science and Art Department, South Kensington, 104, 5 1 1 Science of Easy Chairs, 637 Science Teaching in Scools, 273, 279 ; the Ti7ncs on, 434 Scientific Associations and Societies, 21, 345 Scientific Bibliography, see Bibliography Scientific Education in France, 574 Scientific Nomenclature, Uniformity of ("Divide etimpcra"), 142 Scientific Research and a Brewery Laboratory, 503 Scientific Worthies, XIII., Sir George Biddell Airy, Astro- nomer-Royal, 689 Scott (W. L.), his .Magnophone, 285 Scottish Crannog, Discovery of. Dr. Robert Munro, 695 Scottish Meteorological Society, 262 Scndder's Catalogue of Scientific Serials, 318 Sea, Average Depth of the, 450 Seabroke (G. M.), on the Microphone, 129 Sea-vSerpent Explained, Dr. Joseph Drew, 4S9 ; E. H. Pringle, 519; C. Bird, 519; Dr. Andrew Wilson, 519; Dr. C. M. Ingleby, 541 Secchi's " Meteorologica Romano," 601 Sedg%vick Memorial Fund, 186 Segeburg, Bed of Salt near, 705 Seiches of the Lake of Geneva, Dr. F. A, Forel, icx3 Seismograph and Earthquakes, 533 Selenate of Ammonium, the Action of Heat upon, Dr?, Davy and Cameron, 472 Selenogi-aphy, Recent Progress in, 541 Senebiera didyma, the Inflorescence of, Prof. Alex. Dickson, 50S Septic Organism, the Life-History of a, Rev. W, IL Dallinger, F.R.S., 102 Seth Thomas Clock Company's Clock with Calendar, 575 Settle Cave Exploration, 96 Severn Tunnel Springs, Notes on the Waters from, W, Lant Carpenter, 474 Severn's Telephone for Deaf People, 132, 169 Sewage and Fanning, 133 Sexual Selection and Dress, 632 Shakerly (Jeremiah), his Astronomical Works, 281 Shells, Transportation of, Dr. Charles Darwin, F.R.S., 120; Arthur H. Gray, I2i Shenstone (W. A.), a School Laboratory, 347 Shoa, Proposed Italian Colony at, 131 Siberia : the New University, 399 ; the Extinction of the Mam- moth in, H. H. Howorth, 483 Siebold (Dr. Carl Theodore von). Honours Conferred on, 48 ; Testimonial to, 373 Siebold (Dr. Louis), a New Method of Alkalimetry, 473 Siemens (Dr. C. W., F.R.S.). on the Microphone, 129; Address at the Paris Meeting of the Iron and Steel Institute, 574 ; on Electric Lighting, 650 Sight, Liebreich's "School Life in its Influence en Sight and Figure," 534 Silk Cocoons, Production of, in Europe, 105 Simpson (Prof. Maxwell, F.R.S.), Opening Address in Secticn B at the British Association, 441 Nature, Nov. 2t, 1878] iNDkk XIX Simson (Alfred), the Hearing of Insect?, 540 Siren, Improvements in the, 381, 382 Siren Fog Signal, the Irish, 484 Sitzungsberichte der Miinchener Akademie, lo5 Siwalik and Pikermi Faunas, I'liDcene, njt Miocene, W. T. Blanford, 501 Skertchly (S. E. II.) and S. II. Miller, "The Fenland, Ta.t and Present," 514 Slate and Slate Quarrying, D. C. Davie^, 10 Slavs, the Spread of the, H. II. Howorth, 479 Slieve GulIiDn, the Ancient Volcanic District of, 475 Sloths, Recent Observations upon the Placentation of the, J. C. Gallon, 686 Sniee (Alfred, F. R. S.), Memoir of, 380 Smith (B. Woodd), Remarkable Form of Lightning, 302 Smith (Frederick), Bees, 313 Smith (H. H.), Exploration of the Amazon and Brazil, 466 Smith (\V. H.), the Tailed Amphibians, 193 Snake, the Structure and Development of the, Prof. W. K. Parker, F.R.S., 202 Snakes, Fear of, in the Primates, 227 Soap, the Pedetic Action of, Prof. Stanley Jevons, F.R.S., 440 Social Science Congress, 705 Socialism in South Africa, F. E. Colenso, 194 Society of Arts, Medals, Papers, &c., 652 Solar Eclipses : Total of, July 29, 1878, 261, 353, 394, 401, 425, 43 ^» 457» 462; Prof. Newcomb's Instructians for Observa- tions, 181 ; of May 16, 1882, and August 18, 1887, 199; the Total of 1883, 261 ; of May 28, 1900, 358 Solar Halo, E. Rodier, 13 Solar Photography, Janssen's New Method, H. F. Blanford, 643 Solar Radiation, M. R. Radau's Work on, 63 Sjlar Spectrum: Photograph of, 271; Report on Oscillation Frequencies of the Rays of the, 505 ; Dr. J. C. Draper on the Presence of the Lines of the Oxygen Spectrum in the, 654 Solar, see also Sun Solenoids and Unipolar Induction Currents, 106 Sohd and Melted Materials, the Relative Specific Gravities of, 397, 464 Sorby (H. C, F.R.S.), the Colouring of Birds' Eggs, 426; on a New Method of Studying the Optical Characters of Mineral-, 684 Sound, Transmission of, by Wires, W. J. Millar, 12; the Various Methods of Determining the Velocity of, 558 ; on the Nature of Vibratory Motions, Prof. A. M. Mayer, 571, 594, 648 ; on the View of the Propagation of, demanded by the Acceptance of the Kinetic Theory of Gases, S. Tolver I'reston, 253 ; the Structure of Fluid Columns which are affected by, R. II. Ridout, 604 South Kensington : Natural History Museum, 21 ; Science and Art Department, 104 Southern Hemisphere and the Mediterranean, the Tides of the, Capt. Evans, F.R.S., and Sir William Thomson, F.R.S., 670 Southwell (G. James C), " The Epoch of the Mammoth," 245 Space, the Co-ordination of, 323 Spain, Science in, 49, 105 ; Education in, 484 Sparrow-like Bird, a Fossil, 204 Sparrows, Parental Affection in, 489 Spectra of Metalloids, Spectrum of Oxygen, Dr. A. Schuster, 269 Spectroscopy : an Eclipse Spectroscope, J. Norman Lockyer, F.R.S., 224; a New Spectroscope, 350; Measuring Scale for Pocket Spectroscopes, Prof. A, S. Herschel, 300; Spec- troscopic, la, A. Cazin, 564 ; Professors Liveing and Devvar *' On the Reversal of the Lines of Metallic Vapours," 109, 321 Spectrum of Electric Light (Jablochkoff), E. Walker, 384 Spectrum, Photography of the Least Refrangible End of the, Capt. W. de W. Abney, F.R.S., 163 Spence (J. M.), the Land of Bolivar, 230 Spence-Bate (C, F.R.S.), on the Crustacea, 483 Spojicer (Herbert), Dinner to, 132 Spengel's Translation of "Huxley's Anatomy," 298 iipergularia marina, on the Stipules of, Prof. Alex. Dickson, 507 Spheroid, the Precession of a Viscous, G, H. Darwin, 580 Spicer (Rev. W. W.), Handbook of the Plants of Tasmania, 327 Spider, Basilica, the Snare of the, 387 Spiders, Power of Stupefying, possessed by Wasps, William E. Armit, 642 ; Henry Cecil, 695 Spinoza, the Monument to, 372 ; his House at the Hague, 683 Spirit-Levels, the Displacement of the Bubble in, 272 Sponges, the Structure and Development of, 307 Spores, Resting, Dr. E. Perceval Wright, 173 Spottiswoode (\Vm., F.R.S.), Inaugural Addre s at the British Association Meeting at Dublin, 404 Stil (Prof. C), Death of, 237 Stanford's Stereographical Map of the British Isles, 19 ; Geo- logical Map of London, 235 ; Compendium of Geography and Travel, 378 ; Map of Cyprus, 520 ; Maps of the Indian and Afghan Frontiers and of W^estern Asia, 647 Stanhope "Demonstrator" or Logical Machine, R. Harley F.R.S., 506 Stanley (H. M.), " Through the Dark Continent," 175 Staples (H. J.), Lightning Phenomenon, 67 Stars: Mira Ceti, 180 ; Measures of Double, 225; the Binary .Star a Centauri, 225 ; the " Temporary Stars " of Kepler and Anthelm, 281 ; Further Re earches on the Scintillation of, 292; Double, 334; the Reported Observation of "Vulcan," 383 ; Olber's Star near 7 Pegasi, 426 ; Researches made at Dunsinkon the Annual Parallax of, by Prof. R. S. Ball, 505 ; Variable, 520, 570 ; the Mean Parallax of a Star of First Magnitude, 669 ; J. R. Hind, F.R.S., on Stellar Objects seen during the Eclipse of 1869, 663 ; a Missing Star, 696 Star-fish, a New Fossil, 476 Star-fishes, the Comet Forms of, 252 State Aid to Science, 629 " Statics," Minchin's, 247 ; Oscar Thorpe's, 247 Statistical Society's Prize Essay, 372 Steam, Heating Towns by, 183 Steering of Vessels, Effect of the Reversed Screw on the, 46S Steering, the Mallory Propeller, 465 Stellar Objects seen during the Eclipse of 1869, J. R. Hind, F.R.S., 663 Stereographical Map of the British Isles, 19 Stereoscopic and Alternate Vision, W. M. Flinders Petrie, 115 Stewart (Prof. Balfour, F.R.S.), on the Diurnal Range of the Magnetic Declination as recorded at Trevandrum Observatory, 25 ; Eastward Progress of Terrestrial Magnetism, 38 ; the Variations of the Diurnal Range of the Magnetic Declination, as recorded at the Prague Observatory, 242 ; is the Sun One- sided? 487 ; Sun-Spots and Weather, 616 Stimulants of Savages, 351 Stone (J. Harris), a Meteorite, 464 Stoney (Dr. Johnstone, F.R.S.), and Prof. Reynolds, on tae Spectrum of Chlorochromic Anhydrids, 473 Storm Warnings, American, Jerome J. Collins, 4, 31, 6i ; Dr. Woeikof, 517 Storm*:, Prof. Loomis on, 2S8 ; Storms of the Pacific State-, 335 ; the Great Storm of September 15-16, 680 Strasburg, New University Buildings at, 214; Number of Students at, 374 Streams and Rivers, the Conservancy of, Edward Easton, C.E., 452 Streeter's "Gold," 115 "Strickland's Zoological Nomenclature," 436 Stridulating Crustaceans, 53, 95 Strike, the Influence of, on the Physical Features of Ireland^ Edward T. Hardman, 506 Struve (Prof.), Visit to Western Europe, 502 " Studies in Physical Science," W, J. Millar, 693 Styria, Bone-Caves in, 618 Submarine Cables, the Electric Current in, 106 ; a Cable on Fke, 632 Sugar, the Amount of, in the Nectar of Various Flowers, 474 Suhl, Mineral Spring at, 706 Suicides among Austrian Students, 293 Sulphuric Acid, Chemical Action of, 317 Sun : Eclipse of the, July 29, 1878, 261, 353, 394, 425, 430 ; Prof. Newcomb's Instructions for Observations, 181 ; J. Norman Lockyer, F.R.S., 353, 394, 401, 457 ; Dr. Henry Draper, 462 ; is the Sun One-sided ? Prof. Balfour Stewart, F.R.S.,487 ; Sun and Earth, F. Chambers, 619 Sunday Society, 291 ; the Opening of Libraries, 533 ; Art Exhibitions, 601 Sunshine, Relative Duration of, at Kew and Greenwich, 296 Sun-Spots : Sun-Spot Frequency and Zodiacal Light, 148 ; Sun- Spot Periods and CommerciaL Failures, 372; Sun-Spots and XX INDEX [iVaimr, Nov. 2i, 1878 the Rainfall of Brazil, Orville A. Derby, 3S4 ; SunSpots and Rainfall, C. Meldrum, F.R.S,, 564; Sun-Spots and Weather, Fred. Chambers, 567; Prof. Balfoiir Stewart, F.R.S., 616 Swallow, a White, Albinism in Birds, 540, 618 Sweden, Education in, 484 Swedish North-East Passage Expedition, 308, 631, 6S0 Swift (Lewis), Comet of July 7, 520 ; the Discovery of Vulcan, 539 Swinhoe (Robert, F.R.S.), his Collection of Chinese Bird>, 465 Switzerland : Keller's Lake Dwellings of, 664 ; Erratic Boul- ders in, 206 Sydney : Gerard KrefTt and the Trustees of the Australian Mu- seum, 575 ; Proposed Grant to University of, 659 ; Inter- national Exhibition, 683 Symons (G. J,, F.R.S.), on the Rainfall of Ireland, 484 Tait (Prof. P. G.), CliflFord's Elements of Dynamic, 89 ; a New Fog-Signal, 371 Tait (Lawson) : on the Occurrence of a Sacral Dimple and it-; poshiole Significance, 481 Tanna, the Island of. Volcanic Eruptions in, 263 Tapir, East Indian, at Paris, 49 Tashkent, Exhibition at, 534 Tasimeter, Description of the, 368 Tasimeter and Magnetisation, Andrew and Thomas Gray, 329 Tasmania, Spicer's Handbook to the Plants of, 327 Taunton College School, H. P. Knapton, 357 Taurus, the Variable Nebula in, 552 Taxidermy, Practical, Montagu Browne, 37 Tay Bridge, Dundee, Opening of, 159; Description of, A. Grothe, 361 Taylor (J. E,), " Flowers," 276 Tea'--, Japanese Black, 705 Technical Education : in University College, London, 95 ; in France, 317 Tecoma capense, in Natal, 543 Telegraphic Clerks, Diseases amongst, 49 Telegraphy: Practical, R, S. Culley, 166; in Japan, 182; French School of, 318 ; W. II. Preece on Recent Advances in, 484 Telephone : 136, 163, 424, 706 ; Geo. S. Clarke and II. McLeod on, 1 1 ; in Germany, 23 ; E. Cox Walker's Improve- ments upon the, 76 ; Lieut. G. R. R. Savage's Experiments on, 77, 488 ; Alfred Chiddey, 94 ; Method of Showing the Vibrations of, 11 1 ; and Deafness, 132, 169; Prof. Clerk- Maxwell's Rede Lecture on, 159; Selenium and, 169; the Telephone Relay or Repeater, E. J. Houston and E. Thom- son, 194 ; Sensibility of the, to Feeble Currents, 241 ; Navezs', 242 ; Prof. Hughes' Telephone and Edison's Micro- phone, 277 ; Phelps' Telephone, 392 ; the Electro-Magnet a Receiving, F. G. Lloyd, 488 ; W. H. Preece, 540 ; Exten- sive Use of, in America, 599 ; Prof. W. F. Barrett on the, its History, and Recent Improvements, 631, 698 Tempel's Comet, 1873, 1I'» 67, 130, 281, 385 Temperature, Cumulative, Wm. F. Stanley, 41 ; Underground, William Morris, 93 ; B. A. Report on, 505 ; Nocturnal Variations of, at Puy-de-D6me, 608 " Tent Work in Palestine," Lieut. C. R. Conder, 538 Terns and Gulls, Howard Saunders on, 83 Terpin and Terpinol, Dr. Tilden, 55 Terrestrial Magnetism, Eastward Progress of, Prof. Balfour Stewart, 'F.R.S., 38 Terrier, Fetichism in a, 77 Tertiary Flora of North America, L. Lesquereux, 189 Tertiary Fossils, Prof. Gaudry's Work on the, Prof. Boyd Dawkins, F.R.S., 537 Tertiary Rocks, Fossiliferous, on the Grand Bank and George's Bank, A. E. Verrill, 620 Texas, Guano Beds in, 344 Thallium and Lead, Prof. H. E. Roscoe on the Specific Gravity of the Vapours of the Chlorides of, 214 Thenard (M.), Medallion of, 49 Thermodynamics, on the Use of the Virial in. Prof, A. S. Herschel, 39, 142 Thermometer, a New Deep Sea, 348 Thetines, on the, Prof. E. A. Letts, 474 Thibet : Capt. Gill's Travels in, 288 ; Prjvalsky's Exploration of, 496 Thierleben, Brehm's, 496; E. H. Pringle on, 518 Thiers (M.), his Work on Philosophy, 653 Thompson (Prof. Silvanus P.), the Phonograph, 39 ;^Galvano- meter for Lecture Purposes, 264; on Certain Phenomena Accompanying Rainbows, 441 Thompson (Sir Henry, F.R.S.), the Microphone in Surgery, 157 Thomson (Dr. Allen, F.R.S.), Aberrant Sacrum connected with the Oblique Pelvis, 483 Thomson (Dr. Thomas, F.R.S.), Obituary Notice of, 15 Thomson (Sir William, F.R.S.), Floating Magnets, 13 ; on a New Method for Discovering and Measuring /Eolotropy of Electric Resistance Produced by ^olotropic Stress in a Solid, 180; Influence of Stress on Magnetisation, 215; the Micro- phone, 355 ; and Capt. Evans, F.R.S., on the Tides of the Southern Hemisphere and the Mediterranean, 670 Thomson ( Wm.), the Estimation of Mineral Oil or ParafiinWax when Mixed with other Oils or Fat, 473 Thomson (Sir Wyville, F,R.S.), Opening Address in Section E at the British Association, 448 ; the Progress of the Challenger Report, 534 Thomson's Quadrant Electrometer, the Determination of the Scale Value of, 1 10 Thorpe (Prof. T. E., F.R.S.), Treatise on Coal, 133 ; at Salt Lake City, 502 Thorpe (R. 0.,car), "Statics," 247 Thunderstorms in France, 653 Tide-Calculating Machine, a Self-acting, 75 Tides of the Southern Hemisphere and the Mediterranean, Capt. Evans, F.R.S., and Sir William Thomson, F.R.S., 670 Tidy (C. M.), Handbook of Chemistry, 586 Tiger, the Size of the Indian, Sir J. Fayrer, F.R.S., 219 Tilden (Dr.), Terpin and Terpinol, 55 Timber, Indian Building, 317, Col. R. Benson, 569 Time and Longitude, Latimer Clark, 40 ; Cape. J. P. Maclear, 6 ; Rev. S. J. Whitmee, 220 Times, the, on Science in Schools, 273, 279 Tissandier (Gaston), " Histoire de mes Ascensions, 639 Titan, the Satellite of Saturn, 619 Topinard's "Anthropology," Dr. Bartley's Translation of, 192 Tornado at Canton, 394, 466 Tortoises, Gigantic, at Paris, 372 Tottenham Court Road Boring, 469 Toughened Glass, Caution against, 653 Toy (Edmund P.), Circulating Decimals, 541 Trains of Ladies' Dresses, Prohibition of, in Prague, 632 Transportation of Shells, Dr. Charles Darwin, F.R.S., 120; Arthur H. Gray, 121 Traquair (Dr. R. H.), the Genus Ctenodus, 483 Travers (W. T. L.), Climate in Higher Latitudes during Geolo- gical Periods, 27 Tree-Frogs, 271 Trees, Causes of the Ascent of Sap in, 213 Trevandrum Observatory, the Diurnal Range of the Magnetic Declination as recorded at, 25 Triassic Sandstone, on the Filtration of Sea- Water through, Isaac Roberts, 475 Trinidad, Collections of Ferns from, 466 Trocadero Lift, the Great, 393 " Tropical Nature," A, R. Wallace's, Prof. E. Perceval Wright, 140 Trout and Salmon, Fungus Disease in, 48 Tuning-Forks, Scheibler's, A. Cavaille-Coll on, 381 Tupman(Capt.), the Transit of Venus Photographs, 221 Turkish Bath, a Primitive, 633 Tyrone, on the Metamorphic and Intrusive Rocks of Joseph Nolan, 477 Tyson (Capt.), his Arctic Expedition, 521, 551, 681 Underground Monsters, 389 Underground Temperature, William Morris, 93 ; B.A, Report on, 505 Underground Water, B.A. Report on, 469, 503 Unit, the Electro -Magnetic, the Number of Electrostatic Units in, 470 United States : Cincinnati Observatory, 103 ; Study of Marme Zoology at Johns Hopkins University, 181 ; Progress of Science in, 182 ; the Botanical Directory of America, 182 ; the Natural History Society of Wisconsin, 182 ; the Winds in the 198 ; Geological and Geographical Survey Bulletin, 242 ; Report of the Missouri Weather Service, 288; Geological Nature, NvV. 21, 1878] INDEX XXI Maps of Wisconsin and Colorado, 290 ; the American Association Meeting at St. Louis, 316, 532; Dr. Hayden's Surveys, 316, 647 ; American Geological Surveys, Prof. J. W. Judd, F.R.S., 538; Atlas of New Hampshire, 552; Signal Service, 553 ; Entomological Commission Report, 554 ; American Academy of Arts and Sciences, 576 ; Meehan's Native Flowers and Ferns of the, 615 ; Capt. Jones on American Exploration, 667, 694 ; Cincinnati Society of Natural History Journal, 636 ; the Geological Survey, 657 ; Fish Commission, 682, 704; see aho America, New York, Philadelphia, &c. Universities, Natural Science at Oxford, 651 University and Educational Intelligence, 53, 82, 108, 135, 186, 214, 291, 223, 321, 350, 374, 399, 456, 484, 511, 535, 559, 584, 608, 635, 659, 687, 711 Univers^ity College, London, Technical Education in, 95 ; Classes for Women at, 143: Jubilee, 195, 262, 273; New Buildings, 374 University College School, Scientific Society at, 262 University Extension, 82, 85 Upsala, Meteorological Observatory at, 157 Urechites suberecta, J. J. Bowery on, 55 Uruguay, Proposed Railway from, to Rio Grande do Sul, 133 Valparaiso, Natural History Museum for, 435 Variable Stars, 180, 520, 570 Varying Experiences, Thomas Meehan, 334 Vaucluse Meteorological Commission, 435 Vegetable Kingdom, Prof. Caruel's ClasMfication of, 646 Vegetable Physiology, the Chemical Attributes of, fc. 1 1. Vine, 110 Velocity of Light, Albert A. Michelson, 195 Velocity of Sound, the Various Methods of Determining, 558 Venezuela, Earthquake in, 105, 130 ; the Land of Bolivar and its Products, 230 Venus, Photographs of the Transit of, Capt. Tupman, 221 Verhandlungen der k.k. zoologisch-botanischen GeselLchaft in Wien, 660 Verrill (A. E.), Fossiliferous Tertiary Rocks from the Grand Bank and George's Bank, 620 Vertebrates of the Northern United States, Prof. D, S, Jordan, 167 Vesuvius, Mount, Eruption of, 49, 533, 553, 574, 598, 631, 653 ; Proposed Railway up, 598 Vibrations, Articulate, a Method of Recording by Means of Photography, Prof. E. W. Blake, 338 Vibratory Motion^, the Nature of, Prof. A. M. Mayer, 571, 594, 648 Victoria Institute, 56, 188 Vienna: Academy of Sciences, 28, 159, 296, 375, 536, 560 ; Annual Session, 290 ; the Geological Institute of, 287 ; Ver- handlungen der k.k. zoologisch-botanischen Gesellschaft, 154, 660 Virchow (Prof.), the Craniology of the Bulgarians, 290 Virial, on the Use of the, in Thermodynamics, Prof. A. S. Herschel, 39, 142 Viscosity of the Earth, some Results of the Supposition of the, G. H. Darwin, 265 Viscous Spheroid, on the Precession of, G. H. Darwin, 580 Vision : Alternate, 169 ; Alternate and Stereoscopic, AV. M. Flinders Petrie, 115 Volcanic Ash, Fall of, from Iceland, 199 Volcanic Eruption in New Britain Island, 180 ; in the Island of Tanna, 263 Volcanic Phenomena and Earthquakes during 1877, 241 Volcanoes, Reyer's Physics of, 91 ; Reyer's " Vulcanologische Studien," 487 ; the Corpuna, 423 Vole, the Common, the Annual Increase of, 483 Volta (Alessandro), Monument to, 75 Vowel Sounds and the Phonograph, Professors Fleeming Jenkins and Ewing, 340, 394, 454 Vowel Theories and the Phonograph, Professors Fleeming Jenkins and J. A. Ewing, 167 "Vulcan," the Reported Observation of, 385, 433, 495, 539, 616 Wake (C. S.), Classification of Primitive Relationships, 135 Wales, on some New Pre-Cambrian Areas in. Dr. H. Hicks, 477 Walker (E. Cox), Improvements upon the Telephone, 76 Walker (G.), Spectrum of the Electric (JaSochkoft') Light, 384 Walker (K.), Secondary Lunar Rainbow, 618 Walking Stick for Naturalists, 372 Wallace (A. R.), "Tropical Nature," Prof. E. Perceval Wright, 140 ; a Twenty Years' Error in the Geography of Australia, 193 Wallis (Gustav), Death of, 531 Wanklyn (J_. A.) and W. J. Cooper on a Direct Method for Determining the Calorific Power of Alimentary Substances, 481 War, Proposed French School of, 291 Warington (R.), Report on Farming, Madras, 219 Washington, U.S.; the Naval Observatory of, 372; Prof. Nipher's Magnetic Survey of, 466 Wasp, a Hunting, C. L. W. Merlin, 311 Wasps : Under Chloroform, 588 ; Power of Stupefying Spiders Possessed by, William E. Armit, 642 ; Henry Cecil, 695 Wasps' Nests, Spontaneous Combustion of. Dr. A. Ernst, 487 Watches, Phosphorescent Dials of, 504 Water : Underground, B. A. Report on, 469, 503 ; Latent Heat of, at Temperature below 0° C, 679 Water Supply, the National, 121 ; C. E. de Ranee, 73 Waterfalls and Windmills, 274 Watershed, what is a ? 94 Watei spout near Bath, E. Wethered, 194 Watson (George S.), Hereditary Transmission, 116 Watson (Prof. James C), Intra-Mercurial Planets, 433, 495, 616 Watson (Sereno), Bibliographical Index to North American Botany, Sir J. D. Hooker, P.R.S., 325 Watt (Edmund), Hereditary Transmission, 94 Waugh (Major- Gen. Sir Andrew Scott), Obituary Notice of, 145 Weather and Sun-Spots, Fred. Chambers, 567 ; Prof. Balfour Stewart, F.R.S., 616 Weather Case, or Farmer's Weather Indicator, General A. J. Myer, 621, 630 Weather Warning at the Paris Exhibition, 682 Weights and Measures, Tables for the Verification of Standards of, 632 Weights, Measures, &c. , International Congress of, 532 Weismann (Prof.) on Decorative Colouring in Daphnoidae, &c., 226 Westminster Aquarium : White Whale at, 159 ; Manatee at, 238 West Indies : Exploration of, 49; F. A. Ober's Exploration of, 647 Westinghouse Brake, 12 Westinghouse Speed Indicator, 471 Wethered (E.), a Waterspout, 194 Weyprecht (Carl), the Aurora Observations of the Austro-Hun- garian Arctic Expedition, 1872-74, 606 Whale, White, at Westminster Aquarium, 159 Wheatley (H. B.), " What is an Index ? " 632 Wheat>tone's Microphone, 356 Whipple (G. M.), the Determination of the Scale Value of Thomson's Quadrant Electrometer, iioj an Unusual Rain- bow, 696 Whirlwinds : M. Faye on, 352 ; Thomis Dobson, 250 White (Dr. Buchanan), on the Hemipterous Fauna of St. Helena, 135 ; Insects Corroborative of the Nativity of Certain Plants, 278. White (E. W.), " Divide et Impera," 142 White (W. H.), Manual of Naval Architecture, E. J. Reed, C.B., F.R.S., 137 White Grouse, a. Sir J. Fayrer, F.R.S., 518 White Swallow, Albinism in Birds, Herbert W. Page, 540 ; David Robertson, Jun., 618 Whitelegge (Thomas), Gynodioecious Plants, 588 Whitley (Joseph), Experiments on the Relative Specific Gravities of Solid and Melted Materials at the Temperature of Fusion, 397 Wh;tmee (Rev. S. J.), Time and- Longitude, 220; Winds and Currents in the Pacific, 617 Whitworth (W. A.), " Choice and Chance," 616 Whitworth Scholarships, the, 465 Wiedersheim (Prof.), Description of- a Labyrinthodont, 48 Wild Flowers, Familiar, F. E. Hulme, ii William Barends, Voyage of the, to the Arctic Regions, 647 Williams (W.), the Cennis megaceros, 478 Williamson (Prof. W. C, F.R.S.), Fossil Flora of Great Britain, 35 ; on the Supposed Radiolarians and Diatomaceae of the Coal-Measiures, 508 XXll INDE^ {Nature, I^oi>. li, 1878 Wilson (Alex. S.)i on the Amounts of Sugar contained in the Nectar of Various Flowers, 474 ; on the Association of an Inconspicuous Corolla with Proterogynous Dichogamy in In- sect-Fertilised Flowers, 508 ; Notes on Dimorphic Plants, 509 Wilson (Dr. Andrew), the Sea-Serpent Explained, 519 Wilson (Prof. Daniel), on some American Illustrations of the Evolution of New Varieties of Man, 479 Winchester Town Museum, 316 Wind Charts of the North Atlantic, 680 Wind Instruments, Brass, as Resonators, 271 Wind, Observations made at Prague on the, 287 Winds and Currents in the Pacific, S. J. Whitmee, 617 Win;ls in the United States, Prof. Loomis, 198 Windmills and Waterfalls, 274 Wingless Insects of the Falkland Islands, II. N. Moseley, F.R.S., 619 Winnecke (Prof. A.), Notice of Sir G. B. Airy, F.R.S., 689 Wires : Transmission of Vocal and other Sounds by, W. J. Millar, 12 ; Experiments on the Elasticity of, 467 Wisconsin, the Natural History Society of, 182 ; Geological Maps of, 290 Wittrock (Dr.), on Spore Formation, 173 Woeikof (Dr. A.), American Storm Warnings, 517 Wolfers (Prof.), Death of, 75 Women, Classes for, at University College, 143 Women and Scientific Education, 423 Wood (Samuel), " The Bulb Garden," 693 Wood (Searles V,, Jun.), Zoological Geography, 22D, 301 ; Didus and Didunculus, 301 Wood-Mason (Mr.), Stridulating Crustaceans, 53 Woolwich, Balloon Experimen.s at, 620 Working Men's College, 53 World, the Countries of the, Dr. R. Brown, il Wortley (H. Stuart), Sound-Emitting Crustaceans, 95 Wright (Dr. C. R. Alder), I'hysical Properties of Metals, 69 Wright (Prof. E. Perceval), Playfair's " Travels in the Foot- steps of Bruce in Algeria and Tunis," 91 ; " Wallace's Tropical Nature," 140; Resting Spores, 173; Deep-Sea Dredging oft the Gulf of Mexico, 198 ; Club-Root, 279 Wright (Dr. W. J.), Tract on Invariants, 683 Wiirtz (Prof. A.), and a New Laboratory, 392 ; Faraday Lec- ture, 651 Wyld's Map of Cypras, 520 Wyoming, North- Western, Geological Survey of, 315 Yellowstone Geyser Regions, Survey of, 315, 647 Yenisei River, Exploration of, 338 Yorkshire College of Science, 241, 350 ; Calendar, 635 Yorkshire, the Coralline Oolites of, W. H. Iluddleston, 13^ Yorkshire, West, Davis and Lees' Work on, 276 Zeiss (Carl), New " Oil-Immersion " Object-Glass, 240 ; Rev. W. H. Dallinger on, 6$ Zeitschrift der oesterreich. Gesellschaft fiir Meteorologie, 5S4 Zeitschrift fiir wissenschaftliche Zoologie, 350, 373, 399, 5S4 Zinc, Spontaneous Ignition of Hydrogen by finely divided, 679 Zodiacal Light and Sun-Spot Frequency, 148 Zoological Gardens, Additions to, 23, 50, 77, 106, 134, 159, 183, 207, 238, 264, 318, 346, 373, 394, 425, 436, 467, 535, 555. 577. 601, 633, 654, 684, 707 Zoological Geography, Searles V. Wood, Jun., 220, 301 ; Prof. Alfred Newton, F.R.S., 251, 331 Zoological Nomenclature, Strickland's, 436 Zoological Record, 485 ; P, P. C. I lock, 569; E. C. Rye, 615' Zoological Society, 27, 135, 188, 244, 322 Zoological Society of the Netherlands, 3 ^3 Zoologischer Anzeiger, 238 Ziirich, Chemicnl Laboratory at, 503 A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE " To the solid ground Of Nature trusts the mind which buUds for aj^."— -Wordsworth THURSDAY, MAY 2, 1878 RETROSPECT AND PROSPECT IN beginning with the present Number what is prac- tically a New Series of Nature, the journal has reached a definite stage of its career, one at which it will perhaps not be considered out of place that we should make a reference both to its past and future. That Nature has succeeded in attaining the object for which it was started will, we think, be admitted by men of science both at home and abroad; and it is because Nature has become more and more widely recognised as the organ of science all the world over, that at last we are compelled to enlarge it in order to find space for the stream of communications that week after week come pouring in upon us from all parts. If we have, either directly or indirectly, contributed to this spread of a taste for scientific knowledge, this is due to the un- tiring assistance and sympathy which the many students and friends of science in this and other countries have afforded us, and which aid we are anxious to take this opportunity of acknowledging. In the future, as in the past, we are sure this stream will continue to flow, so that the editor's function will, as heretofore, be a modest one. Beyond this we need not dwell on the past and future of the journal. The work accomplished in the past nine years, and the direction in which it has progressed, is a much more important matter. Both writers and readers have, as it were, arrived at a stage of their journey. From it the countries which they have explored are still plainly visible, while those in front of them, never before trodden, even if they show fair promise of being similar to those already traversed, are shrouded in mystery, and may in truth turn out to be very different from what they seem. We may take advantage, then, of this halt to glance at the nine years' crop of knowledge which Nature has recorded ; to consider the scientific progress accomplished in that period, and to seek for the indications afforded as to the lines along which activity may be expected in the future. Vol. xviii. — No. 444 We certainly do live in deeply interesting times. Since the first number of this journal appeared there has un- doubtedly sprung up a much greater general interest in science than was formerly to be found, and questions concerning scientific discovery, research and teaching, have now a much more direct interest to the public than they formerly possessed. No better test of this can be required than the continually growing space given to such matters by the daily press, and the more intelligent discussion of such questions as. the endowment of research, and the importance of science at our univer- sities and in our schools which is everywhere noticeable. The matters to which we have just referred are, indeed, those in which a distinct progress has been made — a progress which we firmly believe is only a small foretaste of that which is to follow. We have, ever since the journal was started, main- tained, through evil report and good report, the crying necessity to the country of a greater endowment and a wider diffusion of pure science, because the one provides us with raw material, the other distributes it, so that throughout the length and breadth of the land, new manufactures in the shape of new applications of science may arise. There are many signs which indicate that the necessity of this, which is obvious at the- present time only to the comparatively few, will be uni- versally insisted upon. If it is not, future historians may have to show how different might have been our conditiort if our mental resources, which are doubtless as rich as our material ones, had been utilised in the same way ; if education had done for mind, what, for instance, coal has been compelled to do for iron. The Government has not been slow to recognise this growing interest in scientific matters. In the period to which we refer a commission, of which the Duke of Devonshire was chairman, and of which the two secretaries. of the Royal Society were among the members, has gone over, and reported at length on, the whole field of scientific instruction and the advancement of science in the three kingdoms. The only direct response made up to the present time by the Government to the recommendations of the Duke of Devonshire's Commission, has been the B NATURE \_May 2, 1878 endowment of scientific workers. The sum of 4,000/. placed at the disposal of a committee of the Royal Society for this purpose, was doubtless a large sum to begin with, and the committee has made a good beginning with it. The question was a delieate and a difficult one, and allowances must be made, but we doubt whethenthe intention of the Government will be fulfilled by increa^g the stipends of professors who are already hard worked at institutions, the managers of which will now have a roost excellent excuse for underpaying them ; or by cutting down the personal grants to investigators to provide small sums for apparatus, which the fund was not primarily intended to meet. Another recommendation of that Commission, namely, the formation of a museum of physical apparatus, comple- mentary to the new museum of Natural History now being erected in South Kensington, has been more than half carried out. A loan Collection of Scientific Apparatus was formed as an experiment, and all, or almost all, have recognised the importance of a permanent museum of this nature. The Duke of Devonshire's commission has given rise to three others, which hare reported on the Universities of England and Scotland ; and there is little doubt that out of these labours much good will come, though very likely it will be long in the coming. We say thig because such ancient corporations as universities are the products of so many conditions that a mere determina- tion to effect organic reforms, without minute examina- tion, may do much more harm than good. The great point now is that the weak points of our university system are no longer within the ken merely of the few. There are hundreds of thousands of people now in the country who can contrast that getting [of knowledge for know- ledge sake, Avhich is the glory of the German system, with that utterly demoralising cramming of things that pay in an examination, which is the disgrace of our own. Enough also is kno^vn of the activity of the laboratories and scientific worksTiops in foreign universities to create astonishment at the masterly inactivity in the matter of original work displayed in some of our own. To recognise such defects as these is half to rectify them. There is now a prospect of science taking its place in our schools alongside of those other branches which until quite recently held exclusive sway in them ; and it is probable that in the course of a few years, British schools will have reached the stage attained by German ones a quarter of a century ago. The foundation of Colleges at Newcastle, Leeds, and Bristol, is among the signs of this increased activity in educational matters, while side by side with these new foundations, Owens College has now arrived at such a pitch of completeness and usefulness that its erection into a university cannot be long delayed. France, as well as ourselves, is now perceiving the advantages of the German system, and before long we may expect to find separate faculties abolished in that country, and the erection of many new universities. That at Lyons is almost already freed from the leading strings of Paris, and others will soon follow. The Government has been largely influenced in another way — not only, indeed, our Government, but the whole civilised world. Never before in an equal period have so many expeditions been organised to distant parts of the world, to bring back rich fruits of pure knowledge of one kind or another. The voyage of the Challenger will for ever mark this century in the history of science, and our country must be. congratulated at having so largely helped in the accumulation of the vast stores of new knowledge which that and other similar expeditions have gained for the use of all.,.; Animal forms new and strange, the secrets of the deepest depth of ocean, the coursing of the blood along the arteries of the Avorld, the building up of a large portion of the planet itself ; such are the topics which we shall hear much of during the next years, as volume after volume of these precious records makes its appearance. It is not the fault of the men of science if the Polar expedition, which our Government, in friendly rivalry with America, Austria, Germany, Sweden, and other countries sent out, will not live so long in story as will the voyage of the Challenger. It is, after all, but a grim consolation that the elaborate instructions drawn up, and the valuable series of facts collected for the use of this expedition, will, beyond question, be found [useful in a not distant future. The lesson we have learnt, however, goes to strengthen the view so definitely expressed by the German committee, that a mere dash to the Pole is precisely the thing that is not wanted. Careful scientific work, chiefly of the physical sort, carried on for a long period of time, and necessarily, therefore, by relays of observers, would in all probability furnish us with a large array of facts, which could at once be applied to the solution of many out- standing questions in various branches of terrestrial physics,} The way of the winds alone, in these weirdest regions of the world, in itself presents a problem which may be of the highest importance. We hope that the enormous sums which have been spent on the observations of the transit of Venus of 1874, will be amply justified by the result which will be obtained when all the observations of Europe and America have been discussed. It remains to be seen whether, when this has been accomplished, the transit of 1882 will have so great a charm for the astronomers as its precursor of 1874. In any case if so much money is to be spent on the determination of a numerical value which can be arrived at by physical means, it is but fair that the interesting physical phenomena which occur during a transit should not be neglected to so great an extent as they were on the former occasion. Those who control expeditions of this kind incur a grave responsi- bility if any avenue to knowledge is barred by them. Our first number contained an account of an eclipse of the sun observed in 1869 i^^ America. We commence our eighteenth volume while again in that country astro- nomers are vying with each other in perfecting their methods to observe the eclipse of next July. Since 1869 our Government has aided three eclipse expeditions ; one to the Mediterranean in 1870, one to India in 1871, and one to Siam in 1875. A precedent has therefore been established by which active workers may profit in the coming time, for every solar eclipse and every piece of work at the uneclipsed sun raises questions — and will doubtless for ever go on raising them — which eclipses alone can settle. May 2, 1878] NATURE Another mark of the recognition of science accorded by our Government has been the increase of the sum placed at the disposal of the meteorological Council, while at the same time a reorganisation of the ad- ministration of the Council has taken place. Perhaps the most startling event which has taken place during the last eight years touching the administration of scien- tific work in England, has been the nomination of the members of this Council by the Royal Society. Among these we do not find one of our distinguished meteoro- logists. We fear, therefore, that most of the meteoro- logical work of the future will lie outside that body, a result which all must intensely regret, for there is enough loyalty to the Royal Society among British men of science to make them wish that everything it touches should succeed. Never before have the larger questions of meteoro- logy attracted so many minds': the connection of solar changes with terrestrial changes and everything which depends upon them, is now beginning to loom out of the mists of obscurity in a most gigantic shape. The subject is one of such intense interest to humanity, that here there must be no hasty work. The magnetician, the meteorologist, and the physicist, must march together with cautious tread, and when they do we shall doubtless in the next few years find the basis surer and surer, and the methods employed freer from that mutual criticism which makes outsiders think that meteorological butter depends more upon the churn than upon the milk. In any case we may congratulate ourselves that the next eight years will in all human probability give us a more unbroken chain of solar facts than that secured during the last similar period of time. It is not only in the larger problems of physical meteoro- logy that progress is being made. Nine years ago found us warning Deal from Valentia. We now, thanks to the public spirit of Mr. Bennett, of the New York Herald, warn Valentia from New York. The laws of the passage of storms over the Atlantic will soon, doubtless, be more within our grasp, and the next decade may enable us to watch the travels of a cyclone over a distance equal to half the circumference of the earth. The Government explorations carried on by the Chal- lenger and other 'expeditions, to which we have already referred, have not been the only ones which made the last decade a very remarkable one. From the time of Marco Polo nothing more wonderful in the way of foreign travel than the stupendous feats accomplished by Cameron and Stanley in Central Africa have been placed on record. In the near future, and perhaps even in a more distant one, we are not likely to have to chronicle anything coming up to the level of the work accomplished by these men. Nor must we omit to mention Warburton, Giles, and Forrest, whose ride across the Australian desert was scarcely less remarkable. Exploration will doubtless still go on, but by the nature of the problem, it must be exploration of the less sensational sort, but by no means the less useful on that account. Although these African and Australian adventures have been the greatest achievements of their kind which we have had to chronicle, there is scarcely any part of the world on which the explorer's activity has not recently left his mark. In fact, between Cameron, who makes a dash across a continent, and the much-to-be-pitied members of our own geological survey, who, according to a recent parliamentary paper, spend a year in mapping a region of twelve square miles, there is an unbroken series of workers, thanks to whose labours, per mare per terras, a complete inventory of our planetary riches is being got together. Coming from exploration to the sciences of observation and experiment, when we have referred to the enormous increase in telescopic power on the one hand, and to the gradual consolidation and new grouping of facts on the other, we have, perhaps, referred to the most salient points. The increase of observing power since 1869, as is best evidenced by the discovery of two satellites of Mars, is simply stupendous ; in that year we chronicled the erec- tion of the Femdene telescope ; since then this telescope has not only been eclipsed actually, but in imagination dwarfed into such dimensions that it may serve as a finder to the telescope of the future. Henceforward the attempts of those who experiment on lo-feet mirrors will be the central point of interest. The development which I our knowledge of the motion of the intimate particles of matter has received during the last ten years from the work done on the kinetic theory of gases and in the exploration of spectroscopic pheno- mena, is greater than we have as yet any idea of. It will not be a surprising thing if, before very long, these two streams of work find their meeting-place as do the Rhone and the Saone at Lyons, when the clear formulae of the kinetic theory, commingling with the already multitudinous but far from organised spectro- scopic observations, shall form a noble river, the molecu- lar science which in the coming time will embrace all others. Another grouping, "of which we have recorded the gradual consolidation, and which is destined to change the points of view from which many Aspects of Nature have been regarded, is that of physiography — a name which conveniently defines the region where the physicist, the chemist, the geologist, and the astronomer, find each a common interest. Such a grouping as this would, of course, be impossible in a planet where the chemistry of extraneous matter, or the origin of its own, presented problems beyond the range of investigation. But pre- cisely because such points as these are continually re- ceiving important developments here, this new grouping is destined to form a centre of an ever-widening interest — an interest from which all must gain, for so surely as all Nature is one, so must the work of each explorer, to be of its greatest value, form only a part of one combined attack. The radiometer and the telephone are products of recent investigations in physics which of themselves are fit to mark an epoch, but first-rate work has been done besides, by Avhich the continuity of the gaseous and liquid states of matter has been demonstrated, and the last gas reduced to a liquid form. The revival of the contact theory affords a new standpoint for electricians, while the ever-increasing analogies between light and magnetism which are being brought forward indicate that before long some vast generalisation may be expected in this direction. On all sides the interest attaching to physical problems is increasing, and it is well that this NA TURE [May 2, 1878 is so, because the chemists among us are for the most part silent, and chemical theory is ahiiost dead in Eng- land ; indeed it would appear as if the centre of gravity of this science had gone bodily eastward, and Berlin and St. Petersburg now replace London and Paris so far at all events as organic chemistry is concerned. But if the chemist has ceased to employ physical tools this is made up for by those large fields of physical work which are being more and more utilised by the physio- logist. The introduction of physical methods into biological research is one which has already borne, and which will in the future bear, rich fruit, and all work of one kind in this direction will be as largely modified in the future by the introduction of physical methods as that of another will be rendered practically a new science by the generalisations of the immortal Darwin. All experimental science will gain by this, for each branch of scientific work reacts upon all others, and while in the future a physiologist who simply knows how to use a microscope and a dissecting knife will be an impossi- bility, physics, on the other hand, will be sure to receive new methods of observation and new instruments from those who have been compelled to invent them for their new needs. We have recorded the completion of, perhaps, the greatest work ever undertaken and carried to a conclusion by any one man. We allude to the planetary tables, the final touches of which were added by Leverrier only a few hours before a death which has left a void in science which it may take centuries to fill. The physical side of geology has attracted much atten- tion during the last nine years, and it has been our privilege to chronicle many investigations dealing with the interior structure and heat and the probable age of our planet. The facts collected by our surveyors with an activity which, especially in America, has been something beyond all parallel, thus find themselves supplemented by theoretical views, the fitting together of which, in the future, will be a work which will be second to none in interest. Of practical applications of science made since 1869 the number is legion, and some are of high order. The ad- vance in navigation, perhaps, is the most striking. We have not only in the way of new instruments the batho- meter, a machine for taking flying soundings, and a perfect compass, but also the Avhole art of navigation promises to be revolutionised by the introduction of new methods. One thing which all friends of science should take to heart, has been abundantly established, the science most applied is the science of which the theory is bound to receive the greatest development. The telephone, duplex telegraphy, steam fog-signals, and the application of elec- tricity to lighting, must also be mentioned. From the prosecution of science itself we must turn to some of its surrounding conditions. We have had to watch, and have recorded with pleasure, the establish- ment of several new societies, and the strengthening of old ones since our first number was issued. Mathematicians have now a strong society ; physical science is now repre- sented in this way by the side of chemistry; while the latest born of these societies, though by no means the least active, is that devoted to mineralogy. We do not suppose the coming time will see a very large increase in the number of these bodies, but we think that it certainly will see a considerable influence of them all upon the Royal Society. It would be a loss universally deplored if the Royal Society were to abate one jot or tittle of its influ- ence, but with active societies all round it representing each branch of inquiry and at once discussing each advance of knowledge in full meetings, it is difficult to understand that the Royal Society may not suffer if some better method than the one at present adopted of providing for the reading of the multitude of papers presented to it is not adopted. From our own English societies we once more come to individuals, and here our task is a sad one. It is almost impossible to name a period of nine years during which death has played such havoc among men of science of all nationalities. Herschel, Graham, Wheat- stone, Sedgwick, Lyell, and Murchison are no more ; Leverrier, the great Leverrier, has gone with Reg- nault, Milne-Edwards, Claude Bernard, Becquerel, and many other Frenchmen of note. America \ has lost Agassiz ; Germany, Liebig, Argelander, Erdmann, Mayer, and Heis ; Russia, von Baer and Madler ; Italy, Secchi ; while in all countries the thinning of the ranks of men of lesser note has been disastrous. We may surely hope that in our new series the sad task of bidding farewell to men who have done their work in science may fall less frequently upon us. Editor T/I£ AMERICAN STORM WARNINGS THE interest excited in Europe, and particularly in England and France, by the weather predictions cabled by the New York Herald to its ^London Office during the past year (commencing February 14, 1877) proves that these warning messages are regarded aS important to the interests of commerce, navigation, and agriculture. The generally expressed opinion as to their accuracy is a favourable one, and is justified, I believe, by the fulfilment of a very large percentage. Such a result of the first year's work affords me unqualified satis- faction. It represents all the success I aimed to attain, and much more than I hoped to win. I will state at the outset that the carrying out of the whole project of warning the European coasts of the approach of storms has depended on, and has been sustained by, the munificence and generous enterprise of Mr. James Gordon Bennett, the pro- prietor of the New York Herald, whose encouragement and support of every undertaking calculated to promote the advancement of science and discovery are well known and appreciated. The work accomplished so far is the result of some years' study of the phenomena of atmospheric movements. The deductions, therefrom, I have endeavoured to reduce to a practical applica- tion in these cabled weather-warnings of the New York Herald. In this, I believe, a useful step has been made in meteorological inquiry, which may lead to greater and more definite results. Before February 19th, 1877, the day on which the first weather warning of the New York Herald (sent on the night of the 14th) was fulfilled, the question as to the possibility of establishing a reliable connection between May 2, 1878] NATURE the meteorological phenomena of the American and European continents was unsettled. In stating this I do not ignore the efforts previously made with that object by many scientific men in Europe, like the late M. Lererrier, Director of the Paris Observatory. In many scientific circles the possibility had long ago grown to be regarded as a probability, and public as well as private efforts were being constantly made toward a thorough investigation of the laws of atmospheric movement and of storms. Indeed the failures, so called, that attended these researches were, in reality, successes of the highest importance to meteorological science, because they taught the investigators to eliminate all that was worthless in theory, and pay closer attention to the simpler and grander facts of nature which direct and patient observation made apparent. The chief difficulty in the way of success lay in the limited area of the physical field of investigation. Local phenomena have been treated as general, and the observations made in a comparatively small district have been used to found the theories applied to a hemisphere. Except in few cases, recent works on meteorology are barren of original information. They are chiefly mad up of quotations from earlier works, and the experiences of isolated observers who, straining after the establishment of narrowly based theories, permit their enthusiasm to lead them to false conclusions. This accusation may, and probably will, be levelled against myself, but I assure the critics that I will submit to any adverse judgment on my work that is based on scientific truth and feel grateful for the enlightenment. Whatever may be the value, or other- wise, of the statements I make, they are based upon personal observations, and depend in no way on the generally accepted meteorological theories with regard to the origin and movement of storms. I aim at winning for my work all that may be due to its merit, while I am willing to bear all the censure for its defects. The importance to the interests already referred to of a system of weather predictions, which can be published for the general information of the people, several days in advance of the events they announce, is one that cannot be disregarded. We find in America that many branches of trade are seriously affected by weather changes, and that timely warnings are calcu- lated to insure against losses that would, in their absence, be sustained. The great grain-growing districts of the Western States have their respective centres to which the produce is brought for sale, storage, and shipment to the eastern sea-board. Sudden and severe storms not only injuriously affect the condition of the roads and other lines of transportation, and thus delay shipments, but also the produce itself; and the anxiety of the farmer for the safety of his crops is equalled by that of the merchant whose capital is invested in that special branch of trade. Hence, both producer and dealer, as well as the transportation agent, anxiously watch the western horizon, and eagerly receive every item of infor- mation bearing on the all-important condition of the weather. The same state of feeling must exist wherever trade flourishes and agriculture represents wealth. Whether the corn be stored in a Chicago elevator ready for shipment to Europe, is borne by the steamship across the Atlantic, or is stored at the centres of con- sumption in England and France, the conditions vary only in degree. The cotton-fields of the Southern States, the cotton ships on the ocean, and the staple stored in the warehouses of Liverpool or Manchester are under the same all-pervading influence of the weather. To the seaman the timely storm warning is of para- mount importance. Whether he threads his dangerous course among narrow channels along the coasts, or sails boldly into the broad ocean, the foreknowledge of an approaching storm causes him to adopt those precau- tions which insure his safety. The dreadful story of shipwreck which has been continued through the annual chapters of the past twenty-five years, will reach its hoped-for ''Finis,'' when meteorological science effectu- ally aids the nautical skill of the mariner in warding off the great dangers of the sea. Then the headlands of every coast will have their signal stations, and the sailor when taking his parting look at the land he is leaving, or getting his first of that he approaches, will see the warning signal that shall tell him of coming storms, and bid him prepare to meet them. In many other respects the value of timely storm signals will be immense. Take, for instance, the case of an army on campaign. The general commanding mus regulate his movements as much by his facilities for trans- portation and supply as by strategic necessities. He must cross rivers and wade through marshes ; climb and hold rugged mountain passes; and secure his communica- tions by substantial bridges and practicable roads. His supplies must be largely drawn over difficult routes, and, perhaps, from districts liable to inundations and heavy snow or rain storms. If he relies on a co-operating fleet, the ships must be guarded against storms in exposed anchorages. In a word, the variations in the conditions of the weather must be recognised in all the operations of an army, otherwise great disasters may overtake it, notwithstanding the valour and endurance of the troops and the skill of the commander. I have watched with the greatest interest the progress of the recent campaign in Bulgaria, and have frequently announced in New York many days in advance the changes of weather that im- peded the Russian progress, endangered the Danube bridges, and filled the Balkan passes with snow. Such calamities as befell Napoleon in 1812, and a portion of the allied forces in the Crimea in 1854-55, would have been avoided if a meteorological service existed at those times to give warning of the weathfcr changes that pro- duced them. If a special military service of meteorologists, such' as the United States enjoys in its Signal Service Corps, was organised in European armies, many of the difficulties incidental to warfare on that continent could be provided against. But as the foundation of such a system must rest on the accuracy of weather predictions by cable from America, the duties of an Army Signal Corps in Europe with relation to the weather would be simplified to a close observation of the western and southern coasts or frontiers, and the forwarding of information to the proper points. At the present time the European western coasts cannot receive by local observations what can be called timely storm-warnings in the strict sense of the term. The British Channel, the Gennan Ocean, the Baltic, and NATURE {May 2, 1878 West Mediterranean, which represent the chief commer- cial areas of home navigation, are near the points where the first weather indications present themselves. It is not surprising, therefore, that notwithstanding the vigilance of coast-observers, and the prompt distribution of warnings from London and Paris, that many vessels are overtaken and fairly surprised by storms within sight of the British and French coasts. The New York Herald warnings have been forwarded to lessen this danger to navigation in European waters, as well as to give notice of bad weather in the Atlantic to vessels bound for our coasts. I shall first deal with the field of observation from the West Pacific Ocean to the Ural Mountains. I will limit my remarks on the general and local phenomena of storms, to which the New York Herald system of cable weather predictions relates, to the field of observation that extends from the western part of the Pacific Ocean in a great but irregular zone, eastward to the line of the Ural Mountains. The irregularity in the width of this field which lies generally between the loth and 70th parallels of northern latitude is caused by our want of information regarding the meteorology of the far northern sections of this continent and of the region in North Africa between the equatorial zone and the northern Umit of the great desert of Sahara, While the prevailing conditions in these regions may be correctly inferred from their relations to contiguous terri- tories, it will be unsafe for the present to base any assumptions thereon, especially when such are not abso- lutely necessary for my purpose in this article. I will therefore refer only to the Pacific Ocean, between the loth parallel and the Aleutian Islands, the North American continent between the same parallel, and the regions of Manitoba and north of the great lakes and Canada ; the Atlantic between a line drawn from the intersection of the 40th meridian and the loth parallel, to the African coast at Cape Blanco ; and the line drawn from Cape Farewell, in Greenland, and the North Cape, in Norway; and Europe between the 30th and 70th parallels. This immense area contains two great oceans familiar to navigators, and the two continents that represent in the majority of their peoples, the commercial enterprise, the power, and the intelligence of the world. It also repre- sents a considerable portion of the earth's surface sub- jected to a diurnal and equal share of solar influence according to latitude. Whatever may be the real effect of the sun's heat and magnetism in producing atmo- spheric perturbations, the field selected is that which they must almost uniformly influence, and on which the extent of that influence is most likely to be accurately determined by scientific observation and study. It will be observed that the oceanic and continental areas are each divided into two sub-areas by well-marked lines ; the oceans by equatorial currents having a general direction from south-west to north-east, and the continents by distinct regions of mountain and plain. The distinction in the latter case is most marked on the N-brth American continent, but is also very clearly defined in Europe. We have therefore eight sub-areas of the field of observation, each exercising its peculiar influence on the movement of the atmosphere over the whole field. The Kt{ro Siwo or Japan current of the Pacific Ocean, which corresponds so closely with the Gulf Stream in the Atlantic, moves north-eastward with a smaller resistance from the north polar waters than the Gulf Stream. The narrow Behriitg Strait, through which the Arctic current must pass southward is even narrower than Smith Sound, consequently the northern waters of the North Pacific maintain a higher general temperature than those of the North Atlantic, but owing to the spreading out of the Kuro Siwo over a greater area than the Gulf Stream covers in corresponding latitudes, the waters of the latter are relatively warmer and probably deeper between latitudes 30° and 60°. Hence a more uniform tempet^tiire overspreads that part of our field of observation represented by the North Pacific Ocean. It is reasonable to suppose that the compensatory flow of polar water toward the equator comes chiefly from the Antarctic regions in the Pacific Ocean and in nearly equal proportions from both poles in the Atlantic. The effect therefore must be, as I suggest, that the surface of ' the North Pacific has a very uniform temperature, making due allowance for latitude. The atmospheric conditions are consequently affected so far as to pro- mote the development of large areas of low pres- sure without many important centres of very violent disturbance. I cannot say if the infrequency of storm centres, as we are accustomed to regard them, on the Pacific, suggested the name, but it cannot be considered an inappropriate one. Violent storms cross the northern parts of this ocean, but they come from the Asiatic con- tinent, and are probably identical with those which had already passed over Northern Europe in their east- ward courses. We have no satisfactory evidence that such storms again pass over Europe, but they un- doubtedly traverse the circumpolar seas, carrying to those regions the great winds and snows that are ex- perienced by whalers and explorers in the far north. Over such an immense area of warmVater surface as the Pacific presents the atmosphere absorbs an extra- ordinary evaporation, and in its general eastward move- ment brings the humid air to the western coast of the American continent, where, by condensation against the mountain chains that extend from Lower California to the Arctic Ocean, it becomes deposited in heavy rains. The liberation of latent heat consequent to this process causes a barometric fall near the coast line, and the development of storm centres which move inland over the Continent, and have been traced from Oregon to Armenia. Cyclones that are developed in the equatorial zone of the Pacific cross the ocean and are experienced on the American coast from latitude 20° to 55°, according to their point of origin, and high or low trajectories. The movements of these storms will be referred to under another head. On the North American Continent the mountain sub- area extends eastward from the Pacific Coast to the line of the Rocky, Mountains. It is represented by a great elevated plateau from four to eight thousand feet above the sea-level, and from three to six thousand feet above the general level of the sub-area of the plains which extends eastward from it to the Atlantic. The peculiar alignment of the axes of the mountain chains running May 2, 1878] NATURE over this great plateau presents' theai as direct] obstruc- tions to the eastward movement of storms, and their influences on the latter are very marked. Indeed the most interesting study in American meteorology is that of the modifications produced by the great mountain plateau of the west, or the disturbances passing over it. The sub-area of the plains is that in which some of the most remarkable phenomena of storms are observed. The valleys of the Mississippi, Missouri, and Ohio, and the basins of the lakes and Gulf of Mexico are the theatres of tremendous storm movements, and are con- sequently the favourite areas for observation chosen by American meteorologists. Within them are ex- perienced nearly every type of storm that traverses the Atlantic toward Europe. Unlike the sub-area of the mountains to the westward, that of the plains is favoured with an abundant rainfall which renders the great expanse fertile in nearly all its sections. The growths of the tropics flourish in the south, and produc- tiveness marks its various climatic zones until the vast pine forests of the north define 'the agricultural limits. The contrast between the two sub-areas is extraordinary, yet their widely different conditions are easily accounted for when their respective meteorological aspects are studied. The Gulf of Mexico, with its accumulation of tropical waters, plays a very important part in creating the prevailing weather conditions of the sub-area of the plains. From it flows a continuous current of warm humid air, which supplies moisture and energy to the storms that descend from the regions of the north-west into the great river valleys. It is the cradle of the equa- torial current that sweeps across the ocean far into the Arctic seas, carrying warmth and verdure to latitudes in Europe far north of the general habitable limit on the American continent. But it is unnecessary to do more than refer to so familiar a region in describing briefly the natural subdivisions of the field of observation. For the Atlantic, like the Pacific, we have the dividing line of the equatorial current of the Gulf Stream. North and west of that line the surface temperature is low, south and east of it very uniform, and along it high. Air in motion over these surfaces is consequently affected by rapid variations of temperature, which affect in turn the energy of the disturbances traversing the atmospheric volume. A very marked effect of this kind is produced when storms leave the Nova Scotia coast, and at once com- mence to pass over the equatorial and Polar counter currents. The pressure falls rapidly, and great gales are induced, but the storm seems to be held for several hours over the region between Nova Scotia and Newfound- land, as if controlled by forces which it strove to over- come. When fairly past Cape Race the movement of the storm is no longer interrupted by the influences of the currents, and makes a very uniform progress towards Europe. When cyclonic storms reach the Florida or Carolina coasts from the Gulf of Mexico their energy seems to be increased when passing over the Gulf Stream, but their courses are not altered very much by the influence of that current. This is probably due to its narrowness when passing along the coast to latitude 35°. Eastward of the Gulf Stream, and over the oceanic region of uniform surface temperatures the energy of the storms decreases somewhat, and the areas of their depres- sions increase. But on approaching the west coasts of Europe the storms again resume their forces and deposit heavy rains. Europe, like America, is divisible into two sub-areas, one of mountains and the other of plains. The eastern limit of the former is that of a line following the Scandinavian Mountains toward the Alpine development into Saxony, thence following the Carpathian mountain outline, and passing southward over Bulgaria and the Balkans to the Syrian mountains. The irregularity of such a dividing line is very apparent, but we may assume that given to be correct enough for our purposes. In crossing the Scandinavian Mountains, Atlantic storms invariably deposit a great rainfall over Norway and pass into the Gulf of Bothnia and Eastern Russia with a reduced precipitation. When on the great Muscovite plains the storms again increase in area, just as they do in the valley of the Mississippi after crossing the Rocky Mountains in Montana; the break in the dividing-line between the sub-areas of mountain and plain in Europe represented by the Baltic and the low lands of Northern Germany, forms a storm gate- way to the interior plains, which is frequently passed by Atlantic disturbances. The mountain systems of Switzerland, Italy, and the Balkan peninsula, perforn^ important parts in modifying the conditions during storm movements in Northern Europe, and have each their peculiar local influences on the weather. If these moun- tains did not form barriers between the regions of great evaporation with their humid winds from the south, and those of Northern and Central Europe, a parallel between the meteorological phenomena of the Missis- sippi Valley and those of Eastern and Southern Russia in Europe could be drawn very easily. Having now roughly sketched the field of observation at present available, and suggested here and there a few points worthy of special consideration, I will endeavour in the next article to explain how storms move over the several sub-areas, and the changes they undergo in each. Jerome J. Collins {To be coniimted.) NEWCOMB'S ASTRONOMY Popular Astronomy. By Simon Newcomb, LL.D., Professor U.S. Naval Observatory. (London: Mac- millan and Co., 1878.) A WORK on popular astronomy by an author so distinguished in the higher branches of the science as Prof. Newcomb, will be welcomed with more than ordinary interest. The main object of the present volume is to present the general reader with a con- densed view of the history, methods, and results of astronomical research, especially in fields of most popular and philosophical nature at this epoch, in such language as to be intelligible without mathematical study ; it has not been designed to instruct either the professional investigator or the special student of astronomy. In his first chapter the author briefly treats of the phenomena of diurnal motion, the motion of the sun amongst the stars, the precession of the equinoxes, of the moon's motion, and of eclipses of the sun and moon, concluding with some account of the calendar. In his 8 NATURE {May 2, 1878 second and third chapters the true or Copernican system of the universe is described, the obliquity of the ecliptic, the seasons, &c., according to this system, the Keplerian laws of planetary motion, and progress from Kepler to Newton. The latter of these chapters is devoted to Newton's discovery of universal gravitation and con- sequences flowing from it; the gravitation of small masses, the figure and density of the earth, the tides, the inequalities in the motions of the planets produced by their mutual attraction, and the relation of the planets to the stars. The three chapters form the first part of the work, or " the history of the world historically developed." The second part is deroted'to practical astronomy, the telescope and the successive improvements and modi- fications introduced in its construction and application down to the present day. The cumbrous yet elaborate form in which an instrument, powerful for its time, was used in the middle of the seventeenth century, is well illustrated by an engraving of the great telescope used by Blanchini in the observations whereby he attempted to determine the time of rotation of the planet Venus upon its axis, one of the instruments constructed by the cele- brated Campani, mounted in the grounds of the Bar- barini Palace at Rome, and extracted from the historical work "Hesperi et Phosphori Nova Phenomena." As specimens of modern optical and mechanical achieve- ment, we have illustrations and descriptions of the great reflectors of the Earl of Rosse and Mr. Lassell, of the Melbourne instrument and the new reflector in the grounds of the Observatory of Paris. The great refractor of the Naval Observatory of Washington is represented in the frontispiece— a reduction from the picture forming one of the series in the last volume of Washington Astronomical Observations; the instrument with which observations have been made that have afforded us the first really satisfactory knowledge of the elements of the orbits of the four satellites of Uranus and the satel- lite of Neptune, and what is of still greater interest, the instrument with which Prof. Asaph Hall has brought to light the two minute satellites of Mars, a discovery justly characterised by Leverrier as one of "the most im- portant observations of modern astronomy.' ' The applica- tion of the telescope to celestial measurement, the meri- dian circle and its use, the determinations of time and of terrestrial longitudes, are also considered, and the author proceeds to treat of parallax in general, and in particular of the investigation of the solar parallax, through the intervention of the parallax of one of the planets Venus and Mars when nearest to the earth. Prof. Newcomb supplies a sketch of progress and results in this direction from the first application of the method to the planet Mars, on occasion of the French expedition in 167 1, when Richer was sent out to the colony at Cayenne, in South America, to secure observations of Mars, while corresponding observations were made at the Observa- tory of Paris, from the discussion of which observations Cassini made what is usually given as the first reliable approximation to the amount of the sun' s parallax, the resulting value being 9"-5. The author, however, remarks upon the determination made by Huyghens at the end of his "Systema Saturnium," as the best of the seventeenth century, the reason, as he states, of its being the best being ' that it was not founded on any attempt to measure the parallax itself, which was then really incapable of mea- surement, but on the probable magnitude of the earth as a planet. The idea of Huyghens was that the earth, being a planet, its magnitude would probably be some- where near that of the average of the two planets on each side of it, viz., Venus and Mars. So, taking the mean of the diameters of Venus and Mars, and supposing this to represent the diameter of the earth, he found the angle which the semi-diameter of the supposed earth, would subtend from the sun, which would be the solar parallax. By a fortunate accident. Prof. Newcomb remarks, Huyghens' s estimate was nearer the truth than any determinations made previous to the transit of Venus in 1769, " his result'for the distance of the sun being 25,086 semi-diameters of the earth, or 99,000,000 of miles." But it is to be noted that if Huyghens had used the correct measures of Venus and Mars, he would have been further from the truth ; his telescopes showing the planets with diameters in excess of the true ones, " he just hit the diameter of the earth, and reached the true solution of the problem." This attempt of Huyghens to ascertain the amount of solar parallax, is not often men- tioned in our astronomical treatises. The section bearing upon investigations of the solar parallax from transits) of Venus, though brief, contains some interesting facts ; the proceedings of the American expeditions for the observation of the transit of 1874, are particularly noticed. It appears that the stations finally occupied by the observers sent out from the United States were, Wladiwostok, in Siberia, Pekin and Nagasaki, Japan, in the northern hemisphere, and Kerguelen Island, Hobart Town, and Campbelltown, Tasmania, Queens- town, N.Z., and Chatham Island in the opposite one. The American astronomers relied chiefly upon the photographic method of observing the transit, as pos- sessing obvious advantages over the old method of noting the contacts, and the author describes and illus- trates by a diagram, how by the use of a telescope of great length— nearly forty feet— difficulties in the measure- ment of the photographs were'sought to be obviated by the French and American parties, as well as by Lord Lindsay. With regard to the success attending the American expe- ditions. Prof. Newcomb, (who it may be remarked was one of the principal agents in the arrangement of their equipment and plans of observation) states that the full number of photographs expected was not obtained at any station — but that the result taking the stations collec- tively, was about half this number ; the British, French, and Russian expeditions were about equally successful, while the most fortunate, as regards weather, were the German parties who were successful at all six of their stations. He adverts to the amount of labour attending the investigation and measurement of the photographs, and with respect to the time when a final result may be expected to be worked ^out from the observations of the transit of 1874, having in view^the comparison of the whole to ascertain how consistent they are with each other, adds: "this cannot be done for several years," yet that upon the question whether it is worth while to send out parties to observe the transit of 1882, which must soon be a subject of discussion among astronomers, the answer must depend very largely on the success of the Maj' 2, 1878] NATURE efiforis made in 1874. We should be inclined to hope, however^ that the results of Mr. Gill's expedition to Ascenii-.n, with Lord Lindsay's heliometer, for observa- tions of the recent close opposition of the planet IVIars, may very materially facilitate a decision upon this point. If, as many practical astronomers have anticipated, an equally reliable determination of the sun' s distance can be obtained from measuring heliometrically the diurnal parallax of Mars at those oppositions when he approaches nearest to the earth, as from the observation by the combined exertion of civilised nations, of a transit of Venus, then it maybe reasonably expected that a method admitting of comparatively such frequent repetition, and involving also so small an outlay, not only as to cost, but labour of preparation, must be preferred by astronomers generally, thus facilitating a proper conclusion with respect to expensive preparation for observing the transit in 1882. After briefly describing other methods of approximat- ing to the amount of solar parallax which have been applied, including M. Cornu's determination from mea- surement of the velocity of light and Leverrier's results from the planetary theories, and the method first suggested by Prof. Galle, by measuring the parallax of the small planets, a method which, in a modified form, was applied with so much success on the occasion of the near opposition of Juno in 1874, Prof. Newcomb sums up results by stating that " from the general accordance of the various methods described, it would appear that the solar parallax must lie between pretty narrow limits^ probably between 8""82 and 8"*86, and that the distance of the sun in miles- probably lies between the limits 92,200,000 and 92,700,000." This, however, it must be observed, appears to have been written before any of the results of the transit [[of Venus were published, as the author expresses the hope that after their discussion the uncertainty may be brought within yet narrower limits. The chapter concludes with an outline of the various investigations of stellar parallax, the most trustworthy values being collected in a tabular form at the end of the volume, and the same has been done as regards succes- sive determinations of the mean parallax of the sun. By thus avoiding the introduction of any considerable amount of numerical detail into the text, the volume is rendered much more readable ; indeed, in this respect we may remark, once for all, that the author's arrange- ment leaves nothing to be desired. The second part of the work further includes chapters on the motion of light as measured by celestial observa- tions, and experimentally on the methods devised or practised by MM. Foucault, Fizeau, and Cornu ; the application of the revolving wheel is explained. A brief outline of the principles of spectral analysis as applied to the heavenly bodies is presented in conclusion. With reference to doubts which have found expression at times as to the degree of certainty attaching to some of the inferences drawn from spectroscopic observation, and remarking that the dark and bright lines in the spectrum are "the letters of the open book which we are to inter- pret so as to learn what they tell us of the body from which the light came, or the vapours through which it passed," the author introduces the question. How do we know but that the lines we observe may be produced by other substances besides those which we find to produce them in our laboratories ? May not the same lines be pro- duced by different substances ? The answer to this question can only be founded upon an appeal to probabilities. "The evidence in this case is much the same as that by which, recognising the picture of a friend, we conclude that it is not the picture of any one else. For anything we can prove to the contrary, another person might have exactly the same features, and might, therefore, make the very same picture. But, as a matter of fact, we know that practically no two men whom we have ever seen do look e.xactly alike, and it is extremely improbable that they ever would look so. The case is the same in spectrum analysis. Among the great number of substances which have been examined with the spectroscope, no two give the same lines. It^is^ therefore^ extremely improbable that a given system of bright lines could be produced by more than one substance." Nevertheless, it is remarked that the evidence of the spectroscope is not necessarily conclusive in all cases. In the case of a single line only of a substance being found in the spectrum of a star or nebula, it would hardly be safe to infer from this alone that the line was really produced by the known substance, In such doubtful instances collateral evidence must be allowed its weight, and conclusions must be drawn with care and discrimination, in accordance with the proba- bilities of each special case. The third part of the work is devoted to a description of the sun and planets, the comets and meteors. The author has had the advantage of outlines of the views of several distinguished students of the physical constitution of the sun, which he presents in their own words. These include notes by Father Secchi, M. Faye, and Prof. Young. On the subject of intra-mercurial planets he remarks upon the fact of suspicious objects thus far having been seen only by amateur observers, and escap- ing the skilled astronomers who have occupied themselves in watching the sun's disc, and appears to consider that this circumstance places their real existence beyond moral probability. He favours the idea that if the motion of the perihelion of Mercury be due to the action of a group of planets, they are each so small as to be invisible in transits across the sun, and during total eclipses, and yet being so large in the aggregate, their number must be counted by thousands, and if seen at all they would appear only as a cloud-like mass. The zodiacal light offers this aspect, and the question arises whether the matter which reflects this light can be that which affects the motion of Mercury, and Prof. Newcomb is rather in favour of this explanation, though, he adds, "a great deal of research — more, in fact, than is likely to be applied to the subject during the present generation — will be required before the question can be settled." The fourth part treats of the stellar universe, the second chapter on the structure of the heavens meriting especial attention. Space will not allow of our- entering in detail upon the contents of this last portion of the volume ; it concludes with an expression of the author' s ideas relative to the much-discussed question of the Plurality of Worlds. This last part will probably possess greater interest for many than the rest of the work, though necessarily entering upon subjects not yet re- moved from the region of speculation. Prof. Newcomb, lO NATURE [May 2, 1878 however, does not mix up what is merely speculative with well-established conclusions in such way as to mislead his readers who may be entering upon the study of astronomy— a failing of too many works issued at the present day. As affording a thoroughly reliable foundation for more advanced reading, Prof. Newcomb's "Popular Astro- nomy" is deserving of strong recommendation. J. R. Hind SLATE AND SLATE QUARRYING A Treatise on Slate and Slate Quarrying, Scientific, Practical, and Commercial. By D. C. Davies, F.G.S. (London : Crosby Lockwood and Co., 1878.) AMONGST the manufacturing industries which, during the last hundred years, have expanded into large proportions is the production of roofing slate. Nor is it difficult to account for this expansion. Building opera- tions have in this period progressed both over town and country, both in' the Old and New World with extraordinary rapidity, while canals and railroads have facilitated the transport of the roofing slates from their mountain sources to all parts of the land, and ships traverse the seas with cargoes of the same material to various countries. Before the introduction of canals and railways into the British Isles, the slates of Wales, Cumberland, Scotland, and Ire- land were restricted to the immediate neighbourhood of the quarries from which they were extracted, and buildings in various parts of the country far removed from these quarries, were supplied with roofing materials from other sources. In many districts tiles of burnt clay formed the only available material, while in others, flag-stones and tile-stones from the Carboniferous, Triassic, or Oolitic formations were extensively used. In the eastern and central districts of England the tile-stones of Stonesfield, near Oxford, those of the Cotteswold Hills, and of CoUy- weston formed an available source of supply ; and it must be admitted that their greyish colour and general appear- ance harmonise well with the prevalent Gothic or Tudor styles of architecture of those districts. To such an extent is this"admitted that_ these tilestoncs (erroneously called " slates ") are still largely used^ in the counties of Northampton, Oxford,^ and Gloucester, even when the Welsh slate might be obtained at an equal or less cost, and, owing to their heaviness, the high-pitched roofs, which are so ornamental, and add so much to the appearance of buildings, became a necessity. Never- theless, the Oolitic tilestones are inferior in strength, lightness, and durability to the latter material, and are only used where aesthetic considerations prevail over those of economy. In no country of equal extent has the art of slate- quarrying reached such proportions as in the British Isles, and especially amongst the mountains of North Wales, which is its principal seat ; and considering the magnitude of the works carried on, the large number of persons employed, and the enormous sums made and lost in this branch of trade, it is somewhat strange that no work specially devoted to the subject of slate quarrying has appeared up to this time. We therefore welcome Mr. Davies' little treatise, in which will be found a large amount of interesting and valuable information regarding the slate industries of North Wales and other districts, gathered from much experience and observation, and placed before the public in a very readable form. Mr. Davies, being a geologist, treats his subject geolo- gically, recounting the various formations of North Wales in which the various " veins " or beds of the best slates are to be found ; and giving numerous details, often illustrated by sketches of the stratigraphical phenomena which are encountered in the quarries. Few people have any idea of the physical impediments which occur in such places. What with dykes, veins, slips, the disappearance of cleavage planes, the local change in texture and com position of the slate itself, and other disturbances and " troubles," it is only a comparatively small proportion of the entire slate-bed which can, even in the best quarries, be converted into marketable slates, of the larger sizes and qualities, known as " Princesses," '' Duchesses," and " Countesses." Hence it is, that while a band of slate-rock, in a favourable position for carriage, and com- paratively free from such impediments to its useful application, is a source of profit, another band, which is not so free from these].'accidents>f stratification, remains a profitless, or ruinous possession. Commencing with th e oldest formation of North Wales, the Lower Cambrian of Prof. Sedgwick, Mr. Davies describes the eminently successful quarries opened in this formation in the Pass of Llanberris, which have proved a source of untold wealth to their fortunate owners. The slates from this formation are generally purple or greenish — locally becoming greyish — and are amongst the smoothest and strongest in Wales. The succeeding formations of the Upper Cambrian and Lower Silurian are also productive of slates — generally of bluish and dark tints — and are worked over the central portions of the mountain region. The value of such beds of slate depends chiefly upon the uniformity and fineness of the grain of the slatej and the facility with which the rock splits along the planes of cleavage — which, as all geologists are aware, are independent of those of bedding. In reference to the origin of the cleavage structure, we are glad to find that the author adopts the " mechanical . theory," which ascribes the structure to the enormous lateral pressure to which the rocks have been subjected when undergoing contortion ; but in enumerating the observers who have contributed towards our knowledge on this subject, he has omitted the name of the late Mr. Daniel Sharpe, whose remark- able papers published in the Journal of the Geological Society (vols. iii. and v.), clearly established the relation- ship between cleavage and pressure, and the structural alterations which have been brought about within the mass of the slate-rock itself, as subsequently confirmed and illustrated by Mr. Sorby, after the microscopical examination of thin sections. The author's notices of slate-production in districts other than those of North Wales are scanty, and consist of extracts from other works. His book is, therefore, mainly valuable for the information it affords regarding the position, structure, and mode of working the bands of slate in the lower palaeozoic formations of North Wales ; and as such it will be found a useful guide-book. May 2, 1878] NATURE II OUR BOOK SHELF Familiar Wild Flowers. Figured and Described by F. E. Hulme, F.L.S., F.S.A. With Coloured Plates. Parts I.-XIII. (London : Cassell, Petter, and Galpin.) There has certainly been a wonderful improvement of late years in the art of chromo-lithography as applied to botanical illustrations ; and the specimens in the work before us are among the best that we have seen. The colouring, the outline drawing, and the general repre- sentation of habit, are all remarkably true to nature. The floral initial letters and tail-pieces, which are stated to be drawn "by various artists," are not so uniformly success- ful. Each part, published at the remarkably low price of sixpence, contains two coloured plates, more than one species being occasionally placed on a plate. The accom- panying letter-press descriptions, though rather shorter than would in many cases be desirable, are written in plain and easy and not too technical language. There is no indi- cation of the proportion of the British flora intended to be included under the designation of "familiar wild flowers ; " but whenever the volume is completed, it will be a useful addition to our popular botanical literature, and well calculated to promote an accurate knowledge of the common plants of our fields and hedges. Heroes of South African Discovery. By N. D'Anvers. (London : Marcus Ward and Co., 1878.) , The Countries of the World. By Robert Brown, M.A., Ph.D., &c. Vol. ii. (London: Cassell. No date.) The Life of Sir Martin Frobisher. By the Rev. Frank Jones, B.A. (London : Longmans, 1878.) There seems to be no end to the number of geogra- phical works published nowadays. Mr. D'Anver's work is a companion volume to " Heroes of North African Discovery," by the same author, already noticed by us. Like its predecessor its numerous pictures and the many adventures of the "heroes" of its pages will render it attractive reading for boys, who, if they read it faithfully, will carry away with them much valuable in- formation. The work does not pretend to anything like minute research, but so far as it goes, it is, we believe, trustworthy. The present volume of Dr. Brown's work, which may be taken as a typical specimen of Messrs. Cassell' s showy popular publications, deals mainly with the United States and Mexico. Dr. Brown has taken considerable trouble to obtain varied information concerning the different States, and his account of them is fairly full and accurate. In a work like this he cannot be blamed for repeating the oft- told story of his adventures in the west and north-west, though the style, rather than the stories, pall somewhat on one. The pictures, we believe, maybe taken as on the whole what they purport to be ; though it is curious to notice the uniformity of Nature under different conditions, and at widely separated places. One of the illustrations connected with Mexico is entitled a " Lagoon in the Sierra Calientes." Dr. Brown will be interested to know that an exactly similar scene is pictured as occurring on the banks of the Ucayli in South America, in " Paul Marcoy' s " Travels ; but as it is doubtful if " Paul Marcoy " was ever many miles from Paris, the "Scene on the Ucayli" may be as mythical as his "Travels." Judging from the formidable list of authorities given by Mr. Jones, his life of the rough, but brave and' even chivalrous old Frobisher must be the result of much research. Mr. Jones seems, however, to be entirely defi- cient in literary skill ; his materials hare been put together in the crudest manner possible. Though Frobisher added little to geographical knowledge, he deserves a place among the heroes of the North-West Passage for his three attempts to discover it. Unfortunately the object of his last two expeditions was to bring home shiploads of the "black earth" which people had been deluded into believing was rich in gold, and all Frobisher' s efforts at discovery were balked. His life deserved to be written, but we cannot say that Mr. Jones has_ shown himself competent for the task. LETTERS TO THE EDITOR \The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of rejected manuscripts. No notice is taken of anonymous communicatiotu. [ The Editor urgently requests correspondents to keep their letters as short as possible. The pressure on his space is so great that it is impossible otherwise to ensure the appearance even of com' munications containing interesting and novel facts.'\ The Telephone The following experiments lately made as to the use of the telephone in connection with a magneto -electric machine, have given results which are somewhat interesting. In the first instance a small medical magneto -electric machine was employed with the result (described by Mr. A. Percy Smith, Nature, vol. xvii. p. 380), of a loud click at each rotation of the bobbins in front of the magnet. Driving the former by means of a small turbine, the clicks combined to form a loud musical note which rose and fell as the speed of rotation was increased or diminished. This note was well heard through a resistance of 32,000 units. A magneto-electric exploder having two horseshoe' magnets, four bobbins, and two rotating armatures was next employed. This gave a loud sound through S7,ooo units of resistance. With a view to test the power of the machine to work through bad insulation, it was tried through about thirty yards of bare copper wire lying on wet grass. The sound was still powerful. A break was then made in the line by cutting it across and dipping the two ends in a fountain basin filled with water. The two ends in the water were about twelve feet apart, and the sound was still perfectly audible. It was found in this experi- ment that it was not necessary to connect the magnetic exploder to earth, and that a sound feebler, but quite distinct, was obtained when only a single wire was led from it. The line was thus from exploder through twelve feet of water to telephone, the other binding screw being connected to a wire simply touch- ing the wet gravel, there being therefore no return line. Again the exploder and telephone were connected to a stretched wire belonging to a fence, at a distance apart of about fifty yards. The wire was supported by fifteen intermediate iron uprights with their ends buried in the ground. Earths were made for the telephone and exploder by means of a clasp knife and a little garden fork. A perfectly distinct sound was heard. Lastly, one terminal of the exploder and telephone were con- nected by a wire, the others being joined by a length of twenty- four feet of thin string dipped into river water and subsequently drawn through a dry cloth. An audible sound was noticed. The above experiments seem to point to two conclusions : — 1. That magneto -electric currents can be employed through exceedingly defective insulation, almost no insulation, in fact. 2. The omission of the earth connection of the exploder seems to indicate that the production of the sound is due either to a very slight leak from the exploder to earth — the machine was inclosed in a wooden box standing on a wooden table^-or, not impossibly, to the rapid variation of potential in the line. ' In the way above indicated it would appear to be possible to transmit the Morse code by means of magneto -electric currents under conditions which would render a battery absolutely inap- plicable. George S. Clarke Cooper's Hill, April 17 : Herbert McLeod ■^Poisonous Australian^Lake Perhaps some of your readers may be interested [in the following : — This year the lakes forming the estuary of the Murray have been very low and the water unusually Avarm. The river is very low and the inflow to the lakes very slight and having a tem- perature of 74° F. Lake Alexandrina— on calm days surface 12 NATURE [Alay 2, 1878 76°, depth 73° — during breezy temperature is 72°. A conferva that is indigenous and confined to the lakes has been produced in excessive quantities, so much so as to render the water uawholesome. It is, I believe, Nodularia spumigera, allied to protococcus. Being very light, it floats on the water except during breezes, when it becomes diffused. Thus floating, it is wafted to the lee shores, and forming a thick scum like green oil paint, some two to six inches thick, and as thick and pasty as porridge, it is swallowed by cattle when drinking, especially such as suck their drink at the surface like horses. This acts poisonously, and rapidly causes death; symptoms — stupor and unconsciousness, falling and remaining quiet, as if asleep, unless touched, when convul- sions come on, with head and neck drawn back by rigid spasm, which subsides before death. Time — sheep, from one to six or eight hours ; horses, eight to twenty -four hours ; dogs, four to fire hours ; pigs, three or four hours. A post mortem was made on a sheep that had thirty ounces of fresh scum administered by the mouth : death was long coming on— about fifteen hours; examination made six hours after. Stomachs : none of the green scum left, all absorbed ; dry grass food in stomachs. Abdominal cavity contained two pints of yellow serum ; heart flaccid, but not pale ; great effusion of serum around it. Lungs, liver, kidneys, and substance of brain healthy and normal, but the dura mater congested. Blood throughout veins and arteries and in both ventricles black and uncoagulable, neither did it become scarlet on exposure to the air. Many sheep that died, on being opened, presented the same appearances, all being without any sign of its presence in the stomachs. This shows that the plant is rapidly absorbed into the cir- culation, where it must act as a ferment and cause disor- ganisation. The cattle will not touch the puddles where the scum has collected and gone putrid. Thus all they take is quite fresh, and the poisoning is not caused by drinking a putrescent fluid full of bacteria as at first supposed. When this scum col- lects on the banks and is rapidly left dry, it forms crusts of a green colour. This has gone out of the Murray mouth into the ocean and been wafted ashore, forming thick beds of green stuff from a few inches to twelve inches thick. When, how- ever, this scum is left in wet pools and puddles it rapidly de- composes, giving off a most horrid stench like putrid urine, or archil in process of manufacture; but previous to its getting into that state it emits the smell of buytric acid, smelling like very rancid butter. There exudes from this decomposing matter a blue pigment which has remarkable properties. Sample tube i contains the fluid as strained off from the scum and will be found full of bacteria. No. 2 is the same with glycerine, and filtered to sepa- rate the bacteria. This fluid- is remarkably red, fluorescent by reflected light, being blue by transmitted light. Spectrum a broad and deep band total at top in the red, but shading off to green, quite cutting off orange and yellow. Chemical properties :— Heat destroys colour; sulphuric acid no action ; nitric acid reddens ; hydrochloric acid, the alkalis, and ammonia, destroy colour ; chlorine and ozone bleach ; light but little action, yet sunlight gradually bleaches ; dries to a mass, retaining colour ; soluble in water, glycerine, and weak alcohol. I think this is allied to the colouring matter of some lichens, is a product of decomposition, and not pre-existing in fresh plants. Its fluorescent powers are remarkable, and the most powerful I have ever met with. George Francis Adelaide, S. Australia, February 11 Transmission of Vocal and other Sounds by Wires The following are notes of- some additional experiments since those recorded in my paper laid before the Physical Society of London, an abstract of which appeared in Nature of 25th inst. 1 . An ordinary iron fence railing was selected containing six lines of wires varying from f\ to \ inch in thickness. These wires were passed through iron supports at every two yards. A disc, mouth and ear- piece, was attached to one of the wires when speaking, singing, whistling, and breathing were trans- mitted through distances varying from twenty to sixty yards, whilst the sound of a small tuning-fork was heard at 100 yards. 2. In an iron fence, with heavy iron top-rail, half inch square in section, and having iron supports at rjery yard, it was found that the above-mentioned sounds could be transmitted through about thirty yards ; the tuning-fork sound, however, was heard at sixty-six yards. In the latter experiment the best results were got with a hollow wooden mouth-piece, pressed against the iron, the ear being connected with the iron by means of a solid body, such as a cork. 3. Some yards of No, 16 copper wire were attached to the ordinary bell-wire connection from one room to another ; another portion of the same copper wire was attached to the brass bell crank in asother room — a lobby intervening ; — speak- ing, singing, and other sounds were readily transmitted ; the tone was low, but clear. For this experiment the terminal discs were of pasteboard, set in metal rims. In the experiments with the iron fence, the sounds were free to pass not only up and down the particular wire selected, thus necessarily doubling the range of distance given above, but suffered breaking up at each support, and consequent distribution through the other wires. Glasgow, April 27 W. J. Millar Westinghouse Brake The experiment shown by the Westinghouse Brake Company was described by Sir W. Armstrong as long ago as 1843, in a paper " On the Efficacy of Steam as a Means of Producing Electricity and on a Curious Action of a Jet of Steam upon a Ball " {Phil. Mag. xxii.). The explanation of the phenomenon as due to the centrifugal force of the diverted jet is given in general terms in Young's "Lectures on Natural Philosophy" (Lecture xxiv. p. 297). R. « April 28 The Oxford Commissioners' Statement May I be permitted to draw attention to the very marked discrepancy between the arrangements proposed by the Uni- versity of Oxford Commissioners for the Animal and for the Vegetables side of Biology ? Assuming, as we fairly may, that by ' ' Physiology " the Commissioners mean Animal Physiology, and supposing — what is by no means improbable — that the future Reader in Invertebrate Anatomy would refuse the Professorship of Zoology ; when that office is next vacant, we see that there would he four University Professors (or Readers) of Animal to one of Vegetable Biology; while we may also note that at Christ Church there is a Reader in Anatomy, and that at no College is there any Reader in Botany. When the efforts, which may fairly be described as violent, to effect the removal of the Botanical Gardens to a peculiarly objectionable site failed, it was hoped that those who, wittingly or unwittingly, endeavoured to paralyse the study of Botany in this place, would have yielded fairly. The suggestions now made lead us to fear that the Commis- sioners have been persuaded to do what the University would not do. At any rate, if the matter is too delicate for the Professor of Botany to deal with, it is to be hoped that other Botanists will make proper representations to the University Commissioners. April 27 B« Contact Electricity If a Volta's condenser be formed of an iron and a copper plate having their surfaces of contact well ground together, it is found that, on placing them together and then separating them, the iron acquires a positive charge and the copper a negative. This occurs so long as the atmosphere surrounding the plates is the ordinary one containing watery vapour and other oxygen compounds. But if the atmosphere contain sufficient hydrogen sulphide, the iron will be found negatively and the copper posi- tively electrified. Sir Wm. Thomson has shown that "a metal bar insulated so as to be movable about an axis perpendicular to the plane of a metal ring made up half of copper and half of zinc, the two halves being soldered together, turns from the zinc towards the copper when vitreously electrified, and from the copper towards the zinc when resinously electrified." Substituting for the zinc half of rirg an iron half, the same effect takes place, but in a less degree ; but if the ring be May 2, 1878] NATURE 13 surrounded by an atmosphere containing sufficient hydrogen sulphide, the opposite effect occurs. Now the needle, when vitreously electrified, turns from copper to iron ; when resmously, from iron to copper. The conclusion to be drawn from these results seems to be that the electrical behaviour of metals in contact is almost, if not entirely, due to the difference of their affinities for one of the elements of such compound gases as maybe in the atmosphere surrounding them. This would be entirely analogous to their behaviour in electrolytes containing these same elements, e.^. iron is positive to copper in an oxidis- ing electrolyte such as water, because of the affinity of oxygen for iron being greater than for copper, while iron is negative to copper in potassium sulphide solution, because of the affinity of sulphur being greater for copper than for iron. J. Brown Edenderry House, Belfast Solar^Halo The following was noticed at Bordeaux on April 4, at II A.M:— I. A well-defined and very complete circumzenithal circle (80° in diameter), of a brilliant white light, passing through the sun. 2. An iridescent circle, larger than the first, and cutting it at two points 60° distant from the sun. The second circle showed more especially the red rays on its con- cavity {i.e. towards the sun), except at the parhelia, where it was bright iridescent. Near the western parhelion the bril- liancy of the mock sun was quite insufferable to naked eyes. The morning was very warm, but the night had been very cold. E- RODIER 29, Rue Saubat, Bordeaux, April 20 FLOATING MAGNETS THE extract from the American Journal of Science describing experiments with floating magnets by Mr. Alfred M. Mayer to illustrate the equilibrium of mutually-repellent molecules each independently attracted towards a fixed centre, which appeared in NATURE, vol. xvii. p. 487, must have interested many readers. It has interested me particularly because the mode of experimenting there described, with a slight modification, gives a perfect mechanical illustration (easily realised with satisfactory enough approximateness) of the kinetic equilibrium of groups of columnar vortices revolving in circles round their common centre of gravity, which formed the subject of a communication I had made to the Royal Society of Edinburgh on the previous Monday. In Mr. Mayer's problem the horizontal resultant repul- sion between any two of the needles varies according to a complicated function of their mutual distaiice readily calculable if the distribution of magnetism in each needle were accurately known. Suppose the distributions to be precisely similar in all the bars and in each to be accord- ing to the following law :— Let the intensity of magneti- sation be rigorously uniform throughout a very large portion, c D, of the whole length of the bar (Fig. i), and let it vary uniforpily from C and D to the two ends A and B. The bar will act as if for its magnetism were substituted ideal magnetic matter,' or polarity, as it may be called, uniformly distributed through the end portions C A and D B ; the whole quantity in D B to be equal in amount and opposite in kind to that of c A, For example, suppose true northern polarity in A B and true southern in B D. The lengths of CA and db need not be equal. Let now A' c' D' B' be another bar with an exactly similar distribution of magnetism to that of A C D B, and let the two be held parallel to one another. The mutual repul- sion will vary inversely as the distance, if the distance be infinitely small in comparison with D B or C A, and if each of these be infinitely small in comparison with C D. If the true south pole s of a powerful bar-magnet be held in a line midway between B A and b' a', at a distance from the * Repr'nt of papers en Electrostatics and Magnetism, § 469 (W. Thomson). ends B and b' infinitely great in comparison with B b', and comparable with the length of each needle, the horizontal component of its effect on each magnet will be a force varying directly as its distance from the central axis. Under these conditions Mr. Mayer's experiments will show configurations of equilibrium of two, or three, or four, or any multitude of ideal points in a plane, repelling one another with forces inversely as the mutual distances, and each independently attracted towards a fixed centre with a force varying directly as the distance. This, as I showed in my communication to the Royal Society of Edinburgh, is the configuration of the group of points in which a multitude of straight columnar vortices with infinitely small cores is cut by a plane perpendicular to the columns ; the centre of inertia of a group of ideal particles of equal mass placed at these points being the fixed centre in the static analogue. The consideration of stability referred to by Mr. Mayer has occupied me much in the numerical problem, and it is remarkable that the criterion of stability or instability is identical in the static and kinetic problems. In the static problem it is of course that the potential energy of the mutual forces between the particles, to- gether with that of the attraction towards a fixed centre is less for the configu- ration of stable equilibrium than for any configuration difTering infinitely little from it.- The potential energy of the attractive force is a func- tion of distance from the central axis, diminishing as the distance increases, and the statement of the criterion may be conveniently modified _g to the following : — For a given value of this function the mutual potential "" energy of the atoms must be 2> a minimum for stable equi- librium. When, as supposed above, the attractive force varies directly as the distance its potential energy is :— C - i r 2r2 where C, c, denote constants, and 2r^ the sum of the squares of the distances of all the particles from the attractive centre. And when the law of force between the particles is the inverse dis- tance, their mutual potential energy is equal to — K-/&log. (DD'D'....) where K, k, denote constants, and D, D', D", &c., denote C the mutual distances between the particles. Thus the con- <* dition of stable equilibrium becomes that the product of j^ the mutual distances between the particles must be a trua maximum for a given value of the sum of the squares of their distances from the attractive centre. A first con- clusion from this condition must be that the centre of gravity of the particles must be the attractive centre. Now the condition of kinetic equilibrium of a group of vortex columns, that is to say the condition that they may revolve in circles round their common centre of inertia is, asproved in mycommunicationtothe Royal Society of Edin- P=ii? B' C' Fig. I. 14 NATURE [May 2, 1878 burgh, that the product of their mutual distances must be a maximum or minimum or a maximum-minimum for a given value of the sum of the squares of their distances from the common centre of gravity;^ and the condition 4 • # imslaile stahle Fig. «. Fig. 3. that this kinetic" equilibrium may be stable is that the product be a true minimum for a given value of the sum of the squares of their distances from the centre of inertia. Taking for example a triad of vortices (or of the little magnetic needles of Mr. Mayer's problem), it is thus obvious the equilibrium is unstable in the case represented by Fig. 2, and stable in the case represented by Fig. 3. The arrow-heads in Figs. 2 and 3 represent the motions of the vortex columns round their centre of gravity. It must be understood that the core of each column revolves also round its centre of gravity in the same direction as the group round the common centre of gravity of all with enormously greater angular velocities. I have farther considered the problem of oscillations in the neighbourhood of configuration of stable equilibrium. The general problem which it represents for mathemati- cal analysis has a very easy and simple solution for the case of a triad of equal vortex columns in the neighbour- hood of the angles of an equilateral triangle. A mechanism for producing it kinematically is repre- sented in Fig, 4, showing three circular discs of cardboard pivotted on pins through their centres at the angles of an equilateral triangle rotating in a vertical plane. The plane carrying these three centres may be conveniently made of a circular disc of stiff cardboard, or of hght wood pivotted on a fixed pin through its centre. Each of the small discs or epicycles is prevented from rotation Fig. 4- by a fine thread bearing a weight, and attached to a point of its circumference ; and on each of them is marked, by a small dark shaded circle, the section of one of the vortex cores in proper position. ' Helmholtz proved that whatever be the complication of motions due to mutual influences among the vortices, their centre of gravity must remain at rest. The rule for placing the vortices on their epicycles is as follows : — Each vortex keeps a'constant distance from its mean position (this being the centre of the epicycle, carrying it in the mechanism) ; each of the radius vectors drawn from the centres of the epicycles to the centres of the vortices keeps an absolutely fixed direction, while the equilateral triangle of the centres of the epicycles rotates uniformly ; and these three fixed directions are inclined to one another at equal angles of 120° measured back- wards relatively to the order in which we take the three vortices. It is easily verified that when the distances of the vortices from their mean positions are infinitely small (that is to say, when the triangle of the triad is infinitely nearly equilateral), the product of its three sides remains constant in the movement actually gfiven by the mechanism, and so does the sum of the squares of the distances of its three corners from its centre of gravity. From the stability of the equilateral triangle it follows' that there must be stability with three equal vor- tices at the corners of an equilateral triangle, and one (whether equal to them or not) at its centre,* . For four equal vortices I have found that the square order, , also is stable. From the stability of the square fol- lows (for vortices or for particles repelling according to inverse distance) the stability of four equals at the corners of the square, and one (whether equal to them or not) at its centre,^ • I have not yet ascertained waM^wrt/^V^//)' whether for^a pentad of equal vortices there is stability also in the pentagonal arrangement, * ' But Mr. Mayer's experiment, showing it to be stable for the magnets, is an experimental proof that it must be stable for the vor- tices, for it is easily proved that if any of the figures is stable with mutual repulsion varying more rapidly (as is the case with the magnets in Mr. Mayer' s experiment), than according to the inverse distance, a fortiori, it must be stable when the force varies inversely as the distance. From the stability of the pentagon I infer (for vortices and for particles repelling according to inverse distance) the stability of the configuration " . Mr. Mayer' s figure * . . shows that the hexagonal order was unstable for his six magnets. I had almost con- vinced myself before seeing the account of his experi- ments in Nature, that the hexagonal order is stable for six equal vortices; and Mr. Mayer's last figure shows that with his magnets the hexagonal order is rendered stable by the addition of one in the centre . . . The instability of the hexagon of six magnets shows the simple polygon to be unstable for seven or any other number exceeding six. Thus Mr. Mayer's beautiful experiment brings us very near an experimental solution of a problem which has for years been before me un- solved— of vital importance in the theory of vortex atoms — to find the greatest number of bars which a vortex mouse-mill can have. William Thomson 1 in the case of vortices or of the static problem when the law of the mutual repulsions is the inverse distance, but not with the law of repulsion with ordinary proportions of linear dimensions and magnetic distributions, in Mr. Mayer's magnetic arrangement. 2 In repetitions of Mr. Mayer's experiments, I have always found this configuration unstable, and for four only the square stable. 3 This configuration of the floating magnets I have found stable, but with less wide limits of stability than the pentagon. * I have not found this, nor any other configuration than the pentagon with centre, stable for six floating magnets. May 2, 1878] NATURE 15 A ROTATING BOOK-CASE "IT 7"E have received from Messrs. Triibner and Co. a VV book-case on a novel principle, the invention of an American, the introduction of which, into local museums would, we believe, be attended with considerable advantages. The accompanying woodcut will rende'r a detailed description of it unnecessary, while the practical advantages of storing books in such a small space will be obvious to every^body. We draw attention to it not so much from its use in a private library, to the owners of which it will at once commend itself, as from the convenient man- ner inwhichbooks and specimens supplementingeach other, may be arranged in close proximity. We believe that if in a museum geological books, for instance, were thus arranged by the side of the geological specimens, references to the former would be more often made than they are at present when they have to be consulted often in another room at a considerable distance away. Of course the more valuable books and the special memoirs should find their place in libraries as they exist at present, but a typical collection of books side by side with a typical collection of specimens such as this neat arrangement suggests would, we believe, form a novel feature which would be greatly appreciated by many students. The four sides of the rotating book- case also afford a capital means of dividing the subjects as well as saving space, almost to as great an extent as the rotating case for art illustrations introduced by Sir Henry Cole into the South Kensington Museum. FAUSTINUS yOVITA MARIANUS MALAGUTI '\17'E are called upon to chronicle a new loss to French ^^ science in the death, on April 24, of the well- known chemist Prof. Malaguti. He Avas born in Bologna February 15, 1802, his father being a pharmaceutical chemist. At the age of sixteen he completed the course in pharmacy at the Bologna University, and undertook the direction of his father's establishment. Although holding himself aloof from political questions, he became unintentionally involved in the complications of 1831, and was forced to leave his native land. He arrived at Paris unfamiliar with the French language, and succeeded in exciting the sympathies of Gay Lussac, who admitted him into his laboratory as, assistant to Pelouze. After finishing a course in the Ecole Polytechnique, he was appointed, in 1843, chemist to the porcelain manufactory at Sevres. Soon after he received the degree of doctor of science, and in 1850, as the result of a competitive examination, was appointed to the chair of chemistry in the scientific faculty of Rennes, a position which he has since then occupied. In 1855 he was elected dean of the faculty. As an investigator Malaguti won a prominent place in the annals of French chemistry, the period from 1833 to 1867 being especially fruitful. Devoting his attention to the theoretical dispute of the day, he laboured un- weariedlyin widening the region of experimental chemistry, showing himself equally at home, not only in the organic and inorganic departments, but also in technical and vegetable chemistry. In inorganic chemistry he devised methods for preparing a variety of metallic oxides, such as cuprous and chromic oxides, in the pure state, and investigated closely the properties of a number of salts and minerals. The extensive occurrence of silver in the blood, in sea-water, coal, salt, &c., as w-ell as the most profitable means of winning the metal, formed subjects for an interesting series of papers in 1849. In the province of organic chemistry, Malagiiti ren- dered his chief services, his exhaustive studies into the principles of etherification and the action of chlorine on ethers and organic bodies in general being models of careful, thorough work. The enormous mass of facts Avhich he gathered together contributed in no small degree to the establishment of the principle of substitution. Among other important researches in this department should be mentioned the discovery of methylal, the study on the action of acids on sugars, the papers on amides and nitrites, &c. The influence of soils on the composition of plants was investigated by Malaguti in the most thorough manner, and led to the general conclusion that the con- stitution of the soil affected the ashy constituents of the plants, but not their physical properties. Equally im- portant was the series of experiments on the division of inorganic matter among the various plant families, on the temperature of the soil and the air, and on the action of various compounds on living plants. Besides these more purely scientific labours he ac- complished no small amount in analytical chemistry, and made some valuable discoveries in practical metallurgy. In addition to his numerous contributions to the periodical scientific literature, Malaguti published in 1848 "Legons de Chimie agricole," and in 1853 "Legons el^mentaire de Chimie," a text-book highly regarded in France, and recently honoured with a new edition. In 1855 he was elected a corresponding member of the French Academy of Science, and in i860 he was ap- pointed an officer of the Legion of Honour. The Academy of Turin, the London Chemical Society, and several other learned societies, numbered him among their honorary members. T, H. N. DR. THOMAS THOMSON, F.R.S. A SERIOUS and protracted illness had removed Dr. Thomson, — who departed this life on Thursday, April 18, — so long from any very steady participation in the progress of botanical research that, except to those old friends who cherish the memory of his more active days, his name has of late been little before the public. Few, however, have done more permanent work in de- scriptive botany, in which department of science his information was not only extensive, but unusually accu- rate, while the range of his acquirements in other branches of natural science was distinguished by a cor- rectness of judgment which, added to no ordinary amount of general knowledge in matters of taste and literature, made him a most delightful and instructive companion. Like many others who have acquired a permanent name in science, he had the advantage of being trained under a scientific father, while his intimate acquaintance with Sir W. J. Hooker, was no small advantage, and not less the having as the constant companion of his youth, Sir Joseph Hooker. i6 NATURE \_May 2, 1878 On his entering as assistant-surgeon in India, a great field was open to him, of which he happily availed him- self. After a participation in some of the miseries of the Cabul campaign, though not actually serving in the expedition, and a narrow escape, in company with Lady Sale, of endless captivity, he was able to devote his time very much to science. He was employed in 1847 and 1848 in the Tibet Mission, a winter residence at Iskardo, a perilous journey along the portion of the Indus which runs beyond Iskardo, though, from the state of the country, he could not pursue its course to Kashmir, and the results of the previous journey gave him the opportunity of publishing a most instructive volume which, for soundness and multiplicity of information can scarcely be surpassed. Dr. Thomson joined his friend Dr. Hooker in Dar- jeling in the end of 1849, after the completion of his arduous journeys in the North-West Himalaya and Tibet, and they spent the rest of the year 1850 in travel- ling and collecting, returning to England together in 1 85 1 . Having obtained permission from the Indian Govern- ment to distribute his botanical collections, which were equal in extent and value to those of Dr. Hooker, after taking part in the preparation of the Indian Flora, he returned to India as Director of the Botanical Garden at Calcutta. On his return to England, increasing infirmity soon made him unequal to any constant participation in the work, but up to a very few weeks before his death he was employed as examiner, his qualifications for which made him a most desirable and efficient colleague. Though in a very failing state of health, he collected last summer assiduously in the neighbourhood of Pitlochrie, and was so fortunate after three times ascending the Sow of Atholl as to rediscover the long-lost Menziesia carulea. It remains only to add that his kind and affectionate dis- position endeared him to all who knew him, and to none more than to the writer of this short and imperfect notice. M. J. Berkeley THE GREENLAND ESKIMO A COMMISSION was appointed by the Anthropolo- -'*■ gical Society of Paris to examine the Eskimo whom M. GeoffroyI St. Hilaire, the intelligent director of the Jardin d'Acclimatation has brought from Greenland. This Commission was composed of MM. Broca, Dally, Girard de Rialle, Topinard, Masard, and Bordier {rapporteur). The following are the details which I have given to the Society as the result of the observations made by the Commission. The Greenlanders, whom all Paris has been to see at the Jardin d'Acclimatation, are six in number, viz., Okabak, thirty-six years ; Majak, Okabak's wife, twenty- three years ; their two daughters, Anna, twenty-five, and Catarina, thirteen, months ; Kojank, twenty-three years ; and Jokkik, forty-one years, who is recognised at once as a half-breed between Dane and Greenlander. These Greenlanders came from Jacobshavn, on Baffin's Bay, on the west coast of Greenland, about 69° N. lat., not far from Disco Bay and Island. In that latitude the temperature in winter falls as low as — 49° C. It differs notably from that which has to be endured by other Eskimo whose habitat extends to the south of Greenland, from Labrador to Behring Strait. Jacobshavn, although belonging to the north district of Greenland, is not, however, the most northern town ; for Bessels has given, as the human habitat nearest to the pole, the town of Ita, in 78° 16' N. ; Ita appears, however, to be only a summer station. At Disco Bay the sun does not rise from November 30 to January 15. It may not be useless to give a rapid glance at the surroundings in the midst of which these Greenlanders live. The flora is rudimentary. The Greenlanders have but little wood at their command ; the little they use is imported from Denmark. The fauna, less poor, is composed, first of all, of the seal, which constitutes the prime material of all their Fig. I.— 1 and 2. Toy dog and seal, cut in wood. 3. Knife to scrape fat off seal-skins. 4. Seal-skin hunting girdle with ivory medallion. 5. Seal-skin pouch. 6. Obsidian lamp. 7. Bone fish-hooks with iron points. 8. Tuft for catching vermin. civilisation — food, light, heat, clothing, boat-building, various implements and utensils — the seal furnishes all. The white bear is sought for its fur, but the flesh seems to be reserved for the dogs. The reindeer is also found in Greenland. According to Dr. Hayes the reindeer is still very abundant in the interior of the land, but the Green- Fig 2. — I. Fur glove with bear claws. 2. Bone knife for cleaning boats. 3. Drinking-spoon. 4. Bone table-spoon. 5- Bone boxes with bundles of thread made of birds' entrails. 6. Bone hook with iron points. landers do not make use of it either as food or as a means of locomotion. Birds are very abundant ; their plumage is used as fur, and their sinews as thread. But the domestic animal is the dog, which they yoke to sledges by means of a small harness of sealskin. The nine dogs which the Eskimo have brought to Paris, and May 2, 1878] NATURE 17 harness to their sledge, are very large. Their white hair» spotted with black and red, is long and abundant ; their ears are erect, head large, their iris of the colour of cafe au lait. Let us, however, examine the more immediate environ- ment of the Eskimo — their house. It is composed of a hillock of turfed earth, of square form, recalling somewhat our military fortifications. It is entered by a low door giving access to a narrow and very low passage, in which the Greenlander himself, notwithstanding his small size, is forced to bend down. The single apartment to which this passage gives access, and the floor of which is lower than the surrounding ground, is ventilated by an orifice in the upper part. It is lighted by two openings on each side of the door, and hermetically closed by strips sewn together of a sort of goldbeater's skin made of the intestines of the seal. This kind of immovable glazing sifts into the apartment a sufficient light, but appears from without altogether opaque. The furniture consists of a sort of camp-bed which occupies the entire half of the apartment, provided with sealskins, and on which the whole family pass the night, after having taken off their day costume, and put on another more ample dress. On the ground a stone basin, said to be of serpentine, the form of which resembles that of a fish, is filled with seal oil, in which are steeped several wicks. The flame which rises from this vessel Fig. 3 —Map of Greenland. gives a sufficient light, and maintains the confined space at a high temperature. The cotton wicks come from Denmark, as also the chemical matches which the Green- landers constantly use to light their briar-root pipes, which, with their tobacco, their alcohol, and their coffee, are sent them each year by the Danes. Their costume is made almost entirely of sealskin. It consists, in the case of the men, of a shirt (Danish), above which is placed a woollen vest. The pataloons are of hairy sealskin ; the boots, under the pantaloons, of sealskin leather. Gloves of fur, armed, when necessary, with bear's claws, blue spectacles — against the wind and the reflection from the snow — complete the accoutrement. The costume of the women is not wanting in elegance. The hair is raised a la Chinoise on the top of the head, and bound into a sort of vertical chignon, tied by a coloured knot. A well-fitting blouse of European mate- rial trimmed with fur, is provided with a hood, in which the mother carries, when necessary, her latest born, as the opossum dots her young. The woman wears very tight breeches of sealskin and high boots reaching above the knees ; red, embroidered with yellow, after marriage ; white, embroidered with green, among unmarried girls. Their arms consist of bows with which they shoot arrows pointed with bone or iron, and similarly made harpoons, which they throw from the hand. When the harpoon is to be thrown into the water it is attached to a cord provided at the other end with an inflated seal- bladder which acts as a buoy and prevents the loss of the wounded animal, which would run away into deep water with the harpoon. Their other apparatus are iron fish- hooks, wooden baits representing fish, coloured, and very well imitated. To these we may add cases of skin which they put on the paws of the dogs when the cold is very intense ; leathern muzzles to put over the snout of the dogs. Smoothing-irons of stone, knives identical with those which iron-tanners use to dress skins, and intended for the same purpose. This will give an idea of all that the Greenlanders have to help them to struggle against the inclemency of their native climate. But an element not less important than the house in the idea of an Eskimo is the boat. The boats, all of seal- skin well stretched over a framework of wood or bone, are furnished with tackle of leather. They are of two kinds ; every man possesses a small boat, the Kayak, a boat decked all over, except in the middle, where it is pierced with a circular opening, into which the fisher insinuates and fits himself, the legs extended under the deck, and where he remains hermetically enveloped around the loins by what looks hke the upper part of a leathern bag fixed to the edge of the hole and attached round the waist. Thus united to his boat, the Eskimo manceuvering his double-bladed paddle produces an im- pression analogous to that which gave origin to the legend of the Centaurs. A large sealskin bottle placed behind the fisher — a sort of swimming-bladder — increases the specific lightness, and renders the whole unsinkable. The other boat, very much larger— the U7nyak—\% used only by the women, who manage it with the children and furniture. Before concluding what relates to the surroundings, one word about the alimentation. The word Eskimo is not the name which they give to themselves. They call themselves Inmtit (the men) ; so true is it that under all climates human vanity prevails {Los Ovibres : Itinuit). The name Eskimo (eater of raw fish) is a malevolent nickname given them by their American neighbours. It is not, however, so well merited now as it was last century, at the time when Crantz observed them. They continue, nevertheless, to eat raw the lard sent them from Denmark and also the lines of the seal. The rest is eaten cooked. This custom of eating raw lard gives rise to the frequency of tapeworm in Greenland. What has been said of their voracity still appears not to have been exaggerated. Like all peoples whose pabulum vita is uncertain, they go two or three days, especially during winter, without food, but on the first favourable occasion they exhibit a gluttony which is not always a compensation. Phthisis is extremely frequent ; it produces about three-fourths of the total mortality, and is almost always- characterised by blood-spitting. If we seek for what relates to intellectual phenomena, we find little artistic sentiment, but great accuracy,, and an easy submission to what has come to them- from Europe. Converted to Protestantism by the Moravian Brothers, they read in the Jardin d'Acclinia- tation a Greenlandish translation of the Bible, which appears sufficient to satisfy their literary aspirations. They sing slowly psalms which their ministers have taught them. Their writing, in Roman characters, is neat, correct, and precise ; it has something of the slow- ness of their movements. An extreme precocity of development seems to charac- terise them. Thus, the young Catharine Okabak, who- was born on October 20, 1876, possessed, on October 20, 1877, four canine teeth, eight incisors, four premolars, in all sixteen teeth. She ran alone and commenced to speak at the age of ten months. Her sister Anna, who- NATURE \_May 2, 1878 is twenty-five months old, has twenty teeth. It is true that this precocity corresponds, as is often the case, to a feeble longevity. The 7netis of forty-one years appears already old, and it is generally acknowledged that in Greenland a man of fifty-five, or a woman of sixty years, is an exception. Young girls are quite formed at from fourteen to fifteen years ; suckling continues for four or five years. Their height is small ; their black hair is straight ; the face broad and flat ; the head is dolichocephalic ; the cheeks are large, plump, and round ; the lips are thick, the lower pendent ; the eyes are small, dark, oblique, like those of the Chinese, and connected by a fold of skin at the level of the internal angle. The teeth are large, yellow, but sound ; the canines a little projecting. The beard is feebly developed, as is indeed the hair in other parts of the body ; the skin is brown and even black among the aged. The following figures give a more precise idea of these peculiarities : — Their mean height is i*46 metres, a figure higher than that which is given by Hearn to the Eskimo (1*299 ™' ^or the men and I'lji m. for the women), but inferior to that of MM. Bellebor and Guerault (i"So m.) ; a figure which places them in the category of small-sized men, i.e., under i'6o m., and between the Veddas {I'SZS according to Bailey) and the Negritos (1*478 m.), after whom we find only the Bushmen. The cephalic index places these Eskimo among the dolichocephalic, one only, the woman, among the sub- dolichocephalic. Their mean index is 73*51 (maximum 76*88, and minimum 70'95). The mean index of Bessels was more dolichocephalic still ; it was 71*37. It should not be forgotten, however, that the figure varies with the locality of the Eskimo. The Eastern Greenlanders of ^'^-M~^\^' Fig. 4.— The Eskimo in the Jardin d'Acclimatation. Davis gave a cephalic index of 71, the Western, 72 ; those of Virchow, 71*8 ; those of Pansh, 72. It is necessary to compare the anterior or intellectual part of the cranium with the posterior part. The results deserve to be given one by one. In Okabak, the total horizontal curve of the cranium being supposed equal to 100, the anterior curve will be represented by 45*2 ; in Kojanki by 48*5 ; in the woman by 48'i ; lastly in the half breed by 44*7 ; I do not speak of the children. It is worthy of remark that this numerical classification corre- sponds exactly with that which each of us had made in estimating the intelligence of each of these subjects, Kojanki and Mrs. Okabak were judged superior to the two others. The mean of the anterior cranium is 46*6, which places the Eskimo in what Gratiolet designates the occi- pital races — those among whom the posterior cranium outweighs the anterior cranium. The mean facial angle is 66*7°. The height of the nose being supposed equal to ioo,''the mean breadth will be 70*5, while among the Cochin-Chinese it is 89, and among the negroes no, 112, and even 115. One index gives very well the measure of the small prominence or flatness of the nose ; this is the antero-posterior nasal index. Among our Eskimo, the breadth of the nose at its base being supposed equal to 100, the mean prominence of that base in front will be 55*5, while the same mean index among Europeans is 66-6. Such are the principal facts I have been able to collect in reference to the Eskimo of Jacobshavn, now in Paris ; they may be defective, because based on a very small number of subjects ; nevertheless, it is to be wished that the director of the Jardin d'Acclimatation will continue the experiment so well begun, and that besides the Nubians and Eskimo he will introduce other representatives of races so interesting and so little known, whom civilisation will, so far as science is concerned, cause to disappear sooner or later. A. BORDIER May 2, 1878] NATURE 19 POZZOLANA MORTAR AND PINE TIMBER THE following letter has been sent us for publication by Prof. Tyndall :— Villa Guastalla, Via Palestro, Rome, April 14 Sir, — A very curious and unexpected circumstance has occurred in Rome, which, as it depends on chemical action, may have some interest for you. Prior to 1870, when Rome became an integral part of the kingdom of Italy, the beams used in the construction of houses were of chestnut wood. After that date a vast amount of building was undertaken and now a whole quarter of the city stands on ground formerly occupied by vineyards and gardens. k In lieu of chestnut, pine was largely used, having been brought via Venice from the Dolomite Alps. The latter was preferable, as being procurable of larger scantling, of greater length and at a less cost. After a few years, the roofs and floors in which the pine had been used were found to be failing. A beam used in a flat roof or in flooring, where it was imbedded in a wall was found to be rotten ; while the body of the beam was perfectly sound. A very considerable sum of money was thus lost, as many of the roofs and floors of the new houses on the Esquiline had to be renewed. But what was the cause of this sudden perishing of the ends of the pine beams, such as had been known to last centuries in Venice ? The answer to this question remained a puzzle for a long time ; until on taking down the scaffolding of the Ministry of Finance lately com- pleted, a complete answer was found. One of its scaffold poles had been imbedded for, say, four feet in the ground ; about its foot was a heap of the debris of Pozzolana mortar, say, six feet high. That part which had been underground was perfectly sound ; that which had . been surrounded by mortar was utterly rotten ; and finally, the remainder of the pole above the ground was perfectly sound. Hence, it was clear that the mortar was to blame. But in what respect did this mortar difter from that used at Venice in which pine wood beams lay embedded for centuries with impunity ? The sole difference was in the use of pozzolana — a vol- canic earth — instead of sand, and as this substance had been used for mortar in Rome and Naples for ages in contact with chestnut beams with impunity, the only logical conclusion is that pozzolana and pine wood have some chemical affinity which causes some of their in- gredients to combine, to the destruction of the latter. Inclosed are a few grains of pozzolana, such as is used for mortar in Rome. Yours faithfully, Henry H. Maxwell, Lieut.-General R.A. Dr. Tyndall STANFORD'S STEREOGRAPHICAL MAP OF THE BRITISH ISLES ly/TR. STANFORD has recently issued a map which ^^^ marks a distinct advance in British cartography, and one which gives us ground for hoping that some day we may be able to equal in this country the work of the geographical establishments of Germany. The map in question represents, in the first place, the United Kingdom, with its hills and mountains standing solidly out from the ground, as if a perfect relief model of the country lit up from the North had been photographed. The plains and valleys are also clearly shown ; on ordinary maps these cannot be distinguished, and yet they are as important features as the hills them- selves. Great 'care has been taken to embody all the usual information without in any way detracting from the beauty of the map. Thus the railways are shown, and cities and towns, so as not to interfere with the physical features, as well as the hills and plains, vales and rivers, are named in a clear yet delicate type. As an example of the information conveyed, we can mark in the map how the giround rises gradually in going west from London all the way to the summit ridge of the Chiltern Hills, and then falls suddenly to the Vale of Aylesbury and the Vale of the White Horse ; the ground again rising gradually to the summit of the Cotswold Hills, and then falling suddenly to the valley of the Severn ; how the headwaters of the Thames all lie on the top of the second ridge, while the first ridge is the boundary between the Upper and Lower Thames Valley, presenting only one vulnerable point, between Walsing- ham and Reading, through which the river can make its way. Mr. Stanford claims that the map is at the same time artistic and scientifically accurate ; and from the examination we have made we believe both claims can be well made out. OUR ASTRONOMICAL COLUMN Transits of Mercury. — After the transit of Mercury across the sun's disc on Monday next. May 6, which will be visible in this country through about half its duration, there remains only one transit of this planet at the de- scending node in the present century ; it will take place on May 10,1891, with the following elements according to Leverrier's tables of sun and planet : — G.M.T. of conjunction in R.A. 1891, May 9, at I5h. 55m. 40s. R.A. ... 46 44 H'l Sun's hourly motion in R.A. ... 2 26'2 Planet's ,, ,, ... — I 1S7 Sun's declination ... -H7 32 1-9 Planet's „ ... +17 18 o'4 Sun's hourly motion in decl. ... -f 0 39"6 Planet's ,, ,, — I 6-7 Sun's horizontal parallax 876 Planet's ,, „ 15-92 S un's semi -diameter 15 50-33 Planet's „ 6-01 Whence the first external geocentric contact occurs at iih. 53m. 19s. at 65° from the sun's north point towards the west, for the inverted image, and the last external contact at i6h. 52m. i8s. at 12° from the north point towards the east. At Greenwich the external contact at ingress takes place at 4h. 50m. 26s. A.M. on May 10, and the sun's centre is in the horizon at 4h. i8'5m., so that Mercury will be only half an hour upon his disc, after observation is possible here. And while the egress of the planet from the solar disc is alone visible in these islands in the transit of 1891, in that of November 10, 1894, at the opposite node — the last phenomenon of the kind in the nineteenth century — the ingress only can be witnessed here, under faroiu-able atmospheric circum- stances, not to be insured at this season ; the first ex- ternal contact at Greemrich taking place at 3h. 55m. P.M. and the sun setting at 4h. i8m. At the sitting of the Paris Academy of Sciences on April 22, a letter from M. Andrd was read, stating that the expedition sent by the Academy and the French IMinister of Public Instruction, to Ogden in the Utah territory for the Observation of the Transit of Mercury in the present month, had arrived safely at its desti- nation. After experiencing very liberal treatment from the French Trans-Atlantic Company, the instruments were admitted without payment of duty at New York, and the observers received free passes on the lines of railway converging in Utah, both for the outward and homeward journeys. The Government of W^ashington placed at their disposal the nearly-finished observatory at Ogden, at the same time undertaking to provide gratuit- ously all necessary appliances for the observations. A telegraphic wire from Washington to Utah was available 20 NATURE \_May 2, 1878 for determination of time, and the authorities of the U. S. Naval Observatory confided to the expedition the photographic instruments which had been employed by the American parties on the occasion of the late Transit of Venus, for comparison with those brought from France. M. Sainte-Claire Deville in communicating these par- ticulars to the Paris Academy, adds — " II suffit de publier tous ces details pour que la gratitude de tous les savants soit acquise k de pareils actes de confraternity scien- tiiique." Kepler's Manuscripts and Relics. — In the last Annual Report of the Director of the Imperial Obser- vatory at Pulkowa, M. Otto Struve, to the Visiting Committee, attention is called to an interesting acqui- sition recently made by this great astronomical establish- ment. It is known that the library possesses in addition to all the notable published works of Kepler, the nearly complete collection of his manuscripts. This circum- stance caused Prof. Galle, of the Observatory at Breslau, to inform M. Struve that certain articles of which the last direct descendants of Kepler, resident in Silesia, were in possession, and which had been religiously pre- served in the family as memorials of their immortal ancestor, might be obtained by purchase, and the result has been that they are now deposited at Pulkowa, to be preserved with other astronomical treasures, which the Struves, father and son, have secured for the institution. Amongst these articles are particularly mentioned two miniature portraits on copper of Kepler and his first wife, at the time of their marriage, and a memorandum- book used by his first wife and continued by his eldest daughter. The Pulkowa Library Catalogue.— In the same Report from the Director of the Russian Observatory, it is mentioned that a continuation of the Catalogue of the valuable library has been some time in preparation, the numerous additions, upwards of 10,000, which have been made to it since the publication of the first Catalogue in i860, rendering a more complete work very desirable. M. Otto Struve justly remarks that the Catalogue of i860 has had its uses beyond the pale of the establish- ment, and we feel sure that workers in almost every branch of astronomy will bear witness to the assistance they have received from that excellent and well-arranged analysis of the contents of this important library, whereby they will have been guided with comparative facility to a knowledge of the literature special to par- ticular astronomical subjects upon which they have been engaged. GEOGRAPHICAL NOTES Round the World. — The French Society des Voyages Autour du Monde, have obtained the steamer Picardic, of the company Valery fr^re et fils, of Mar- seilles, in which to make their intended voyage round the world. The vessel is 1,560 tons and 1,000 horse- power, and is fitted up in the best manner. She is announced to leave Marseilles on June 30 under the command of Lieut. M. G. Biard. The staff is complete, and it is stated that the passenger list will shortly be closed. This project seems likely to have a better result than the much-talked-of American Woodruff Continental Voyage Round the World, which from the first seems to have been utterly hollow, and collapsed on being probed. T'j^Africa. — In his recent journey in East Central Africa, the late Capt. Elton, H.M.'s Consul ^at Mozambique, paid considerable attention to the northern end of Lake Nyassa, which was previously very imperfectly known. He arrived, we believe, at a very positive conclusion that no river flowed out of the lake, but he discovered an important and navigable affluent, the Rombashi River. This he considered to be well suited for the la'.:e end of the caravan road from the coast. This road, which is being constructed by private enterprise and under the supervision of English engineers, starts from Dar-es- Salam, some twenty miles to the south of Zanzibar, and thirty or forty miles of it have already been completed. When finished it will, no doubt, have an important bearing on the future of this part of Africa, and it will open up to commerce and civilisation a region a consider- able portion of which has remained hitherto entirely unexplored. The Abbd Debaize, who recently received a subvention of 100,000 francs from the French Government for pur- poses of African exploration, left Marseilles on April 20 for Zanzibar, where he will arrive at the end of May. He will remain there for some time in order to make the most complete preparations for his journey across the Continent, which is expecjted to occupy three years. The same steamer carried nine French missionaries de- spatched to establish posts at the Victoria Nyanza and Lake Tanganyika. . NOTES Prof. Hughes, the well-known inventor of the type-printing apparatus so largely employed on the Continent, has made the wonderful discovery that some bodies are sensitive to sound as selenium is sensitive to light. If such a body be placed in the circuit of a small battery it will be so affected by the sonorous vibrations when spoken to as to replace entirely the transmitter of a Bell telephone. Conversation, music, and all the sounds transmitted by an ordinary telephone are easily reproduced. A mere scratch with the finger-nail, or a touch with the soft part of a feather is distinctly transmitted. The sonorous vibrations produce strains in the conductor, which cause variations in the resistance of the circuit, and thereby produce similar variations in a current flowing through that conductor. The French deserve all the praise that has been recently lavished upon them for the energy and determination and sound judgment with which they have quietly carried on the preparations tht culminated in the imposing ceremony of yesterday. Their new Exhibition is the one bright spot in the European horizon at present. Even till very recently many-^doubted whether these preparations would ever come to anything, partly on account of the disturbed state of Europe, and partly because the earnest - ness and perseverance of the French as a people were doubted. We have had frequent occasion recently to bring before our readers evidences of the renewed energy of the French in respect of scientific research ; and the unprecedentedly mag- nificent display which now divides the attention of the world with the Eastern crisis, is only one of many other proofs that the French are rapidly achieving for themselves a position more solid than ever they held before. The world, then, is once more taking stock of her industrial riches, and ever since the Exhibitions of Vienna and Philadelphia, the discoveries and applications of science have been so many and so rapid' that the Paris Exhibition must present many new features. For, indeed, however much the great mass of visitors may ignore it, the multitudinous display that was opened yesterday, is simply a specimen of the gifts of science to humanity, as the French themselves would say. Judging from the catalogues British trade is well represented, and our principal scientific-instrument makers are well to the front ; but British culture and British science are nowhere, and, as we have said already, the British Commissioners have lost a splendid opportunity, and will have simply nothing to show beside the magnificent educational and scientific collections of France herself. We have already spoken at length of the many preparations made for represen- tation of French science — scientific conferences, the scientific lectures, scientific excursion^, besides the great display of May 2, 1878] NATURE 21 scientific exhibits ; the British Department will be nothing more than a trade show. Let us hope that the British Commissioners and British visitors generally will return from Paris ashamed of their shoppy display, and filled with a sense of the vast national importance of science, which in the case of France, it will be seen, tnily "exalteth a nation." The large fresh-water and salt-water aquariums in the Troca- dero Gardens at the Paris Exhibition were stocked last week. A regular service of barges is engaged in bringing daily quantities of sea-water from the; coast to supply the second aquarium. The amount proposed- to be spent "upon the building of the new Natural Histoiy Museum at South Kensington for the pre- sent financial year (1878-79) is, according to the Civil Service Estimates, 80,000/., being 10,000/. more than last year. Of this sum, 60,000/. is for the building, which is now verging towards completion, and 20,000/. for internal fittings. We are pleased to see that the authorities are already turning their attention to the last subject, but should they not also begin to think about a library t As regards scientific work, the natiu-al history collections in their new house will be absolutely useless without a library. Our readers may possibly think that a scien- tific library may be got any year by the use of a certain quantity of money, but they will find themselves very much disappointed when they attempt to try this experiment. The fact is, such a library as is required for the use of a great national museum can only be picked up by slow degrees, and so soon as it was deter- mined to move the collections away from the great public library in Great Russell Street, steps should have been taken to form a new one for the collections in their new site. This, however, does not appear to have been thought of yet. Our readers will be glad to hear that Prof. Clifford, who is at present at Gibraltar, is somewhat better. There was a convetsazione at the Royal Society last evening. The Vice-Chancellor of Cambridge University has appointed Prof. Clerk Maxwell Rede Lecturer for the ensuing year. An agreeable variation on the daily news from Constanti- nople is the report of the completion of the Museimi of Anti- quities in the Turkish capital. In 1875 Arifi Pacha, the Minister of Instruction, ordered the renovation for this purpose of an old kiosk on the Seraglio Point, built in 147 1 by the conqueror of Constantinople, and the work has been pushed steadily for- ward, even despite the war, until now a spacious edifice, richly decorated with marble, is ready to receive the archaeological col- lection of the city. Visitors at Constantinople who have found their way to the dark, dusty hall in the arsenal, where quantities of valuable antiquities were crowded together in chaotic confu- sion, will appreciate the value of this ample provision for their exhibition, especially for the extensive collections resulting from Schliemann's excavations at Troy. A school of archseology is to be established in connection with the museum. We have variety enough of Associations, learned and other- wise, in this country, but none corresponding to that which met on April 24 and subsequent days at the Sorbonne, composed of the delegates of the various learned societies throughout France, and founded by Leverrier many years ago. We have the elements for such an association in abundance ; and, indeed, concretions of greater or less extent have begun to form in different parts of the countiy. There is, for example, the Cumberland Association, which met last week, and which, if not founded by our national astronomer, like the French Association, had the honour of listening to what he describes as probably his last public lecture. Then there is that extensive association of societies and field-clubs in Yorkshire, which publishes a journal of its own ; and most recent of all, there is the Midland Union, with head-quarters at Birmingham, extensive ramifica- tions, and " running " an excellent magazine, the Midland Naturalist. But there is room for something more national and more universal than any of these, and not interfering with their action at all ; and as a preliminary step we would suggest that a general meeting of delegates from the various local societies throughout the ^kingdom should be held at some central city. Such a meeting might be useful in many ways, leading as it might do to united action with regard to common interests, as useful, indeed, in respect to our local societies, as the recent Conference of Librarians has been to the libraries of the world. If properly organised we believe the meeting would become an annual institution. The President of this year's meeting, the sixteenth, of the French Learned Societies, was M. Milne-Edwards, who devoted his opening address mainly to the memory of the Association's founder, Leverrier. The number of delegates was smaller than in former years, many of them having postponed their visit to Paris till the Exhibition was opened, and the discussions seem to have lacked the keenness and impressiveness which always cha- racterised them when Leverrier presided. The first two days were devoted to sectional meetings, and on the concluding day the distribution of prizes took place, as usual under the chair- manship of the Minister of Public Instruction. An immense crowd had been attracted in the hope of hearing from M. Bar- doux himself what was the intention of the Government with regard to education ; but he postponed any definite statement to the month of October, when the association will hold a supple- mentary meeting after having taken part in the several scientific congresses and lectiu-es held at the Trocadero. He reviewed all the improvements realised last year in the educational system of France. ** Soon," he said, "everjrwhere when the want will become manifest, libraries, laboratories, and collections will be established exhibiting the passionate zeal of Government for everything which touches the superior interest of instruction. A time will soon arrive when every hamlet will have its o^vn school and when the tools of intellectual work will be at the disposal of every seeker." There can be no doubt of the sjon- pathy of the present French Government for every form of scientific effort. Some important scientific papers were read during the meeting, but we cannot at present do more than mention the fact. In the scientific section gold medals were assigned to M. Cailletet for the liquefaction of gases. Dr. Armand for explorations in Cambodia and Laos, General de Nansouty, founder of the Observatory on Pic du Midi ; Prof. Terquem for physical researches, and Prof. Houel for mathe- matical works. Although no allusion was made by M. Bardoux in his address at the Sorbonne to the contemplated improvements meditated for French meteorology, we can state that he will ask from the French Parliament a credit of 10,000/., and 2,000/. for five successive years, in order to organise in France ten large meteorological observatories, possessing each a com- plete set of registering instruments. The contemplated institu- tions, some of which have been already created, will be located at Lille, Paris (Montsouris), where M. Marie Davy will be continued superintendent, at the country seat of Mr. Herve- Mangon in the department of La Manche, where a private observatory has already been organised, at Bordeaux, Toulouse, Marseilles, Lyons, Besan9on, and the three elevated observa- tories, Pic-du-Midi, Pny-de-D6me, and Mont Ventoux. The Annual Meeting of the Cumberland Association for the Advancement of Literature and Science may now be regarded 22 NA TURE [May 2, 1878 as an established institution. The gathering at Cockermouth on Monday and Tuesday last week was large and successftil. The event of the meeting was no doubt Sir George Airy's Address, which we hope to give next week, but there were other addresses and papers read which would do credit to more pretentious associations. The president, Mr, Isaac Fletcher, M. P., F,R.S,, in his address, gave an interesting sketch of George Graham, the eminent horologist of the eighteenth century, who was a Cumber- land man, Mr. Clifton Ward, to whom the success of this Association is largely due, read a valuable paper on Quartz in the Lake District, The telephone of course was exhibited, and several interesting excursions made ; and last, not least, the Report tells us that the Association and its affiliated Societies are prosperous. Why should not each county or group of comities, have a similar association ? The Midland Union of Natural History Societies, numbering over 2,000 members, are to have their meeting at Birmingham on May 27 and 28 ; and judging from the brief programme it promises to be an interesting one. With independent sources of many-sided and vigorous activity in the country like Birmingham, there is no danger of over-centralisation. An alarmuig paragraph recently appeared in the Swiss corre- spondence of a German paper, which, affecting as it' does the existence of the St, Gothard tumiel, we are sxirprised that it has not been even referred to in English journals. The paragraph stated that the great engineering undertaking of • boring through the St, Gothard was threatened by the possibility of a severe check in a direction hitherto unexpected. "The geologists engaged in the work," it was stated, "have lately noticed a peculiar depression of the strata through which the tunnel is jDrogressing, leading to the suspicion that a subterranean sea occupies the interior of the mountain chain at this point. The last report laid before the Swiss Federal Council, states that these indications are becoming more and more decided, and it is expected that the next 700 feet of boring will yield decisive proofs for or against this theory. If the fears prove true, the whole of the work on this magnificent undertaking, will come to an abrupt and unfortunate conclusion." These sentences par- take of the usual character of what may be called "newspaper science." They contain just enough of scientific phraseology to impress the ordinary reading public with the importance of their announcement ; while at the same time their statements are so vague as to afford the reader \Aho knows something of the subject no means of deciding whether the thing is a hoax or may have some kind of foundation in fact. Happily the apparently insu- perable difficulty has been boldly faced with the usual results. A recent report of the inspector of the tunnel states that the irregular : character of [the formations pierced by the timnel, which led to the above fears, has entirely ceased, and that the M'ork is now progressing through uniform regular strata. On the south side the boring progresses at the rate of ten feet daily through gneiss. The rate is somewhat less on the north side, where the tunnel is not yet out of the serpentine. The thickness of this stratum of serpentine now being pierced is already the double of that estimated by geologists from the surface indica- tions. The forty-ninth anniversaiy meeting of the Zoological Society was held on Monday, The report of the Council stated that the number of fellows, fellows-elect, and annual subscribers, at the close of the year 1877 had amounted to 3,358, showing a net addition to the list of 47 members during the year 1877. The income of the Society in 1877 ^^^ amounted to 30,988/., being, Mith the exception of 1876, a larger total than the re- ceipts of any previous year since the foundation of the Society. The total ordinary expenditure of the Society in 1877 had been 27,290/., the remaining sum of 1,711/. having been devoted to certain special objects, such as new buildings. The Society has purchased the freehold of the present house (11, Hanover Square), and of the house immediately adjoining it at the back (314^, Oxford Street). The total assets of the Society on December 31, 1877, had been calculated to be 17,989/., while the liabilities were reckoned at 4,019/. The total number of visitors to the Society's gardens during the year 1877 had been, according to the report, 781,377, a number gi-eater than had been recorded in any previous year except in 1876. With re- gard to the state of the menagerie, it was stated that the total number of animals belonging to the first three classes of verte- brates living in the Society's menagerie at the close of 1877 had been 2,200. The total number of i-egistered additions to the menagerie in 1877 had been 1,260. The Marquis of Tweeddale, F.R.S., was re-elected president; Mr, Robert Drummond, trea- surer ; and Mr, Philip L, Sclater, Ph,D,, F,R.S., secretary to the Society for the ensuing year. The new members of the Coun- cil elected were — Sir Joseph Fayrer, K.C.S.I., F.R.S., Lieut.- Col. Godwin-Austen, Dr. Giinther, F.R.S., Dr. Edward Hamilton, and Prof. Huxley, F.R.S. Dr. F. V. Hayden sends us a first proof of a plate to appear in one of the volumes of the Bulletin of the U.S. Geological Sursey, in which is represented the greater part of a fossil skeleton of a very remarkable new bird about to be described by Mr. Allen under the name Palaospiza lella. Though we have not heard of or from Mr. Benson for some time, he has not been idle. Two papers by him are now before us. In one of these ("Facts and Figures for Mathematicians ; or, the Geometrical Problems which Benson's Geometry Alone can Solve ") the problem is, " given the area of a circle, say of one acre, to find that of another circle, which being described from a point as centre, on the circumference of the given circle, shall have that portion of its area outside the given circle equal to the area of the given circle." A similar problem to this vexed us in our undergraduate days. We were required to find by purely geometrical means (if possible) the length of a chain which, fastened to a stake in the boundary of a circular field, would aflow an ass to graze over just half the field. Mr. Benson says the solution depends upon the actual, not the supposititious properties of the circle, and therefore the result as given in the Scientific American (where the ratio of i to i •158728 is stated to be the one required) " which is based upon the false supposition that the circle has similar properties to those of the polygon " is erroneous. It may be remembered that Mr. Benson will have it that the value 3*1415926 X R^ for the area of a circle is wrong. As we stated in our notice of the " Geometry," oiu: author maintains that the reasoning mathematicians employ to get this result is fallacious, and in his opinion he makes this easily evident. He still holds that 3R^ is the area. " A man convinced against his will Is of the same opinion still." Mr, Benson argues more suo in the twenty-two pages which he devotes to the problem. The second publication (" New Mathematical Discoveries ") is a four-page one, and is concerned with the discovery of Archimedes that the pro- portion between the parabola: and the rectangle on abscissa and ordinate is in the proportion of 2:3, From the proof employed to show this, he comes round to the circle again, and gets area = 3R^, To judge by the printed letters, Mr. Bensoii has adherents to his views; among them one a graduate of the Polytechnic School in Paris, writes that "they (these discoveries) will revolutionise the mathematical world," and he is translating them for publication in France, Mr, Ben- son (whose motto should be " indefessus agendo ") is engaged upon "Philosophic Thoughts in all Ages" and "Geometer's Manual," containing history of geometry and correspondence May 2, 1878] NATURE 23 with prominent English and American mathematicians on new geometrical subjects. Our author has a mission ; if any hold with him, they should write to L. S. Benson, 149, Grand Street, New York City, and become the happy possessors of a copy of " Facts " for thirty cents. De gustibus non disputandum. The North China Herald reports a curious desire for im- provement on the part of two Corean medical men, who belong to a nation which has hitherto shown itself the most determined in its self-isolation. These men have applied to Dr. Dudgeon, the Superintendent of the London Mission Hospital, for per- mission to attend there during the stay of the Corean embassy at Peking. .They are described as very intelligent men, and they speak very disparagingly of their own medicine. For years they have been studying Hobson's medical works in Chinese, and they have also obtained Dr. Dudgeon's Anatomical Atlas. They are greatlyjnt crested in vaccination, and wish to introduce it into Corea. The stringency of Corean laws pre- vents natives from living out of their own country, but the next time the embassy visits Peking these two men intend to devote more time to the study of foreign medicine and surgery. Although the existence of kerosene oil in several of the provinces of Japan is said to have been known for 1,200 years, the Japanese did not know how to refine it tiU about six years ago. Now, however, refining establishments are springing up rapidly, and its manufacture is becoming an important industry. At Dresden a new journal appeared on May i entitled Zeit- schriftfiir Museologie und veriuandte Wissenschaften ; the editor is the Director of the celebrated " Griine Gewolbe," Hofrath Dr. Grasse, the publisher, Herr T. M. Hofmann. Thus the circle of "collection-journals," /.^.journals for archives, libraries, and museums, is complete. A German inventor has found a new use for asbestos, in the shape of leaves for a bank-note-album. These albums are said to protect bank-notes or other valuable documents to such an extent, that if they are laid between the leaves and the album is closed firmly, they ^even remain legible after being burnt to cinders. Mr. F. C. Penrose writes to the Times ivonn Copse Hill, Wimbledon, that on April 24, at 8.12 P.M., he saw an unusually fine meteor descending at a very steep angle, and when first noticed, at about 2° to the north of the bright star Procyon, and sloping a little to the north. It was yellowish, and although not in itself intensely bright, from its apparent size (5' long and 3' broad by estimation), surpassed the light of Venus at her maximum. It was as usual pear-shaped. After a course of about 10° from the point first mentioned, it left behind it three or fomr very bright blue star-like points, and vanished in a clear sky at about an altitude of 22° and 57° west of south. No sound of explosion was heard. A Peruvian chemist. Dr. Arosemano, will exhibit an inven- tion at the_Paris Exhibition, which may become a very important one for commerce. He has succeeded in obtaining a magni- ficent dye from the violet or maroon Welshcorn of Peru, and this dye is said to impart the colour, odour, and taste of claret to alj light v.'hite wines to such a degree, that it is impossible to dis- tinguish the coloured wine from real claret, without being in the least injurious to the health of the consumer. Besides this a number of other uses are mentioned to which this Welsh corn- dye can be put. The German Telegraph Office is rapidly introducing the telephone ; 68 stations are already provided with this instrument, 41 others will have it in a few weeks, and 1 1 1 more before the end of the year ; thus there will be then a total of 220 telephone- stations in Germany, To commemorate the looth anniversary of the discovery of the Sandwich Islands by Cook, a statue of the great discoverer will be erected on Diamond Peak, a burnt-out crater near Honolulu. Seven extremely interesting pictures are now being exhibited at Berlin by the painter, Herr J. L. Wensel ; they represent scenes from the second German North Polar Expedition during the years 1869 and 1870, and are executed after sketches made on the spot by several members on the staff of the expedition. The Conference on the National Water Supply, in connec- tion with the Society of Arts, will meet on the 21st and 22nd inst., and will be followed on the 23rd and 24th by a Confer- ence on the Health and Sewage of Towns. The additions to the Zoological Society's Gardens during the past week include a Beisa Antelope {Oryx beisa) from North- East Africa, presented by H.H. the Sultan of Zanzibar ; an African Leopard {Felis pardus) from Africa, presented by Mrs. Kirk; a Black Wallaby [Halmaturus ualabatus), a Laughing Kingfisher {Dacelo gigantea) from Australia, presented by Mr. D. W. Barker, jun. ; a Sand Lizard {Lacerta agilis), a Smooth Newt {Triton tocniatus), Eiuropean, presented by the Masters W. L. and B. L. Sclater; a Common Seal {Phoca vitidina) from British seas, a Cariama {Cariama cristata) from Brazil ; a Guira Cuckoo {Guira piririgua) from Para, a Crested Curassow {Crax alector) from Guiana, a Bar-headed Goose {Anser indicus) from India, a White-faced Tree Duck {Dendrocygna viduata) from Brazil, a Red-billed Tree Duck {Dendrocygna autumnalis) from America, a Blue-bonnet Parrakeet {Psephofus hccmato-, gaster) from Australia, purchased ; a Bennett's Wallaby {Hal- maturus bennetti), born in the Gardens. T THE UNIVERSITY OF OXFORD COMMISSION HE Vice-Chancellor has received from the University of Oxford Commissioners a Statement with respect to the main purposes relative to the University, for which, in their opinion, provision should be made under the Act, the sources from which funds for those purposes should be obtained, and the principles on which payments from the colleges should be contributed. The statement is somewhat similar to that pub- lished in reference to Cambridge some weeks since, only more detailed. As to the main purposes relative to the University for which provision should be made under the Act, the first in order of these purposes is, in their opinion, the extension and proper endowment of the professoriate, and the better organisation of University teaching. As to which two principal objects should be kept in view: — i. The due representation at Oxford of every considerable branch of knowledge, the advancement of which can be effectually promoted by the University, as a place either of education or of learning and research; and 2. The due participation of the University itself, as distinct from its colleges in the direction and improvement of the studies of its undergraduate and other students. The Commissioners are unable to adopt the views of those who would desire to transfer to the University the whole or the chief part of the teaching work now done by the colleges either separately or by means of intercollegiate arrangements. They think that among the recognised studies of the University there are some (such as natural science) for which the colleges cannot be expected to make adequate provision, either without, or by means of, those intercollegiate arrangements. Many of the existing professorships are inadequately endowed, and ought to have their emoluments increased. Of a few the emoluments are in excess of what we think necessary. There are others the constitution, designation, and duties of which may, when they become vacant, be advantageously modified. The Commissioners also think that some new chairs should be established and adequately endowed. The stipends of the • professors (other than those of the theological faculty) should, in the Commissioners' opinion, be of varying amounts, according to -the relation of their several 24 NATURE [May 2, 1878 subjects to the studies of the University and to other circum- stances material to be considered. Those of the following, among other Chairs should, they think, be augmented, so that the lowest of them should be not less than 700/. nor the highest more than 900/. per annum— namely, Astronomy ; Geometry ; Natural Philosophy ; Chemistry. They would also assign stipends, varying between the same limits, to the following Chairs, constituted by division or modi- fication of existing foundations :— Physics— dividing between these two Chairs the subjects of the present Chair of Experi- mental Philosophy; Physiology; Human and Comparative Anatomy — dividing between those two Chairs the subjects of the present Linacre Professorship. Stipends varying between the same limits should also be assigned to the following new Chairs, which they think ought to be established — English Language and Literature ; Pure Mathe- matics ; Mechanics and Engineering. The stipends of the following Chairs should, they think, be augmented, so that the lowest of them should not be less than 400/., nor the highest more than 500/. per annum — Medicine; Botany ; Zoology ; Geology ; Mineralogy. The evidence and opinions which the Commissioners have received lead them to the conclusion that it is expedient to develop as much as possible those branches of scientific in- struction which are introductory and preliminary to medicine, rather than to attempt the establishment of a practical School of Medicine in Oxford. » It may be desirable to provide a reader in Fluman Anatomy, as assistant to the Professor of Human and Comparative Anatomy, with a stipend of from 250/. to 300/. per annum ; and they think there should also be a reader (with a present stipend of 400/. per annum) in Invertebrate Anatomy, whose office, upon a vacancy in the Professorship of Zoology, should be united to that Chair, with such an increase in the emoluments of the professor as may make them equal to those of the Chair of Human and Comparative Anatomy, conditionally on his undertaking the additional duty. Additional demonstratqrs appear to be required in several departments of natural science, who, in most cases may best be paid by fees, with supplementary grants when needful from the University chest. There are several other purposes relative to the University which they regard as important, and for some of which definite provision ought to be made under the Act. Among these are : — The foundation and endowment of scholarships or exhibi- tions tenable after a certain fixed period of residence in the University, for students in any special branches of study (in- cluding subjects which do not fall within the ordinary University course, such, for example, as medicine), which may be usefully promoted by such encouragement, under conditions properly adapted to make their enjoyment dependent upon the bon& fide prosecution of such studies. The encouragement of research, by the employment of properly qualified persons, under the direction of some Univer- sity authority, in doing some definite work, or conducting some prescribed course of investigation, in any branch of literature or science ; or by offering prizes or rewards for any such work or investigation. The appointment and remuneration, from time to time, by the University authorities, of extraordinary professors or occa- sional lecturers in any subjects, either represented or not on the ordinary teaching staff of the University. The last, and not the least important, of the main purposes relative to the University for which, in the Commissioners' opinion, provision should be made under the Act, is the creation of a common University fimd, to be administered under the supervision of the University, in addition to its general corporate revenues. They look to the creation of this fund (of which the forma- tion must be gradual) as the proper resource for the supply of all the wants enumerated under the preceding head, except such of them as any college may propose to aid in supplying. As to the sources from which funds for the above pur- poses should be obtained, they are of opinion that these funds must necessarily be obtained from the colleges. As to the principles on which payments by the colleges for the above-mentioned purposes should be contributed, it will be necessary to take into account the revenues, actual and prospective, of each college, and its actual and prospective wants for educa- tional and other purposes, before they can form a judgment as to the amount ^^hich it should be called upon to contribute. They think it expedient to retain in Oxford a considerable number of prize fellowships (that is, fellowships not coupled with any specific duty or service to a college or to the University), for the en- couragement and reward of meritorious students. Such fellow- ships should, they think, as a rule, be terminable ; and their present impression is that their emoluments should be of uniform amount and should not exceed 200/. per annum. The Commissioners have already received from some of the colleges proposals made, in a liberal spirit, in harmony with the views which they have expressed ; and -they are confident that they will receive such assistance from the University and the colleges generally, as may be necessary to enable them to deter- mine when, and in what order of priority, provision shall be made for all the purposes^;specified in the first part of this statement. AN IMPROVED METHOD OF PROJECTING LISSAJOUS' FIGURES ON THE SCREEN"- A S is well known, the vibrations of tuning-forks when used ■^ for the production of Lissajous' figures, are kept up either by the constant application of the violin bow, or by the aid of an electro-magnet ; the former method requiring the presence of two assistants, and the latter adding materially to the complexity of the apparatus, and not unfrequently failing to produce the desired result. The difficulty is overcome in the present appa- ratus by the substitution of harmonium reeds for the tuning forks, the entire instrument being easily controlled by one operator. The apparatus consists of a base board on which are planted the two reed boxes A and B. The box A is placed horizontally in such a manner as to be capable of slight rotation in the horizontal plane, and also of adjustment in height, by means of the support to which it is attached being provided with a slot and set screw. The box B is permanently attached to the base board in the" vertical position. The boxes are so placed that a pencil of light Calling directly on E would be reflected to B about one inch from its top ; they are furnished with clamping screws for the attachment of the reeds. The boxes are entirely open on the sides facing each other, their margins being covered with soft leather on which the reed plates bed, making a sufficiently air-tight joint. Wind is supplied through the brass tube C which gives off a branch to each box, a stopcock DD' being inserted in each branch. The reeds are similar to those used in the con- struction of harmoniums ; they are mounted on brass plates which fit the reed boxes. The tongue of each reed is furnished, at its free end, with a small reflector of microscopic covering- glass (E) silvered by Liebig's process, a piece of cork or pith being interposed between the tongue and the reflector, so as to free the latter from the frame of the reed ; the reeds are then tuned in the usual manner. It is not necessary that the reeds should be in absolute tune, as, within certain limits, their relative vibrations can be adjusted by means of the stop-cocks, an advantage of great value, believed to be solely possessed by this apparatus. The reed in the vertical box gives the fundamental ratio of vibrations from which the intervals are built up. Two funda- mental reeds are used interchangeably, one giving the double or « Paper read at I,it. and Phil. Soc, Manchester, February 5, by J, Dixon Mann, L.K.Q.C.P.) May 2, 1878] NATURE 25 eight feet C of musicians, the other, being an octave lower in pitch, adds an octave to the intervals obtained from the first fundamental ; thus, the third with the first fundamental becomes the tenth with the sub- fundamental. The horizontal box is furnished with a set of reeds giving all the intervals up to the twelfth, including the unison. The horizontal reeds are changed for the production of the different figures, the fundamental reed being retained. A free space of half an inch was allowed between the supply pipe and the reed box, so as to afford a cushion of air capable of )delding to the elasticity of the tongue. The supply pipe is contracted at its termination to about one-third the size of the hole in the reed box through which the wind enters. The apparatus is used as follows : — The base board being firmly clamped to a rigid table, one of the fundamental reeds is clamped in front of the box B : another reed, giving the desired interval, is similarly clamped to the box B ; an elastic tube, about half an inch in diameter, is attached at one end to the pipe C, and at the other to an acoustic bellows. A fine pencil of light is now thrown on the mirror E, which is then adjusted by rotation of the box A until the light strikes the mirror of the vertical reed, from whence it is reflected on to a screen of tracing paper placed a short distance away ; a con- denser, interposed between the lantern and the mirror E, focuses the spot of light on the screen. On the bellows being put in motion the figure appears, and can be brought to a perfect stand in any phase of development, looped or cusped, by careful manipulation of one or other of the cocks. The entire apparatus should be as rigid as possible, and free from any vibration other than that produced by the tongues of the reeds, and also that the wind supply should be perfectly steady. THE PARIS OBSERVATORY A' S we announced some time ago, an important step has been ^ taken for the reorganisation of the Paris Observatory. A decree of the President of the French Republic has appointed ten members of the new council of the Observatory, in pursuance of the provisions of the organic decree we referred to two months ago. The principal object of this new institution being to connect the observatory with the several large French administra- tions, three Government departments have sent two delegates each. The War Office is represented by Col. Laussedat, the director of the balloon service, and Commander Perrier, the chief of the Ordnance Survey ; the Minister of Marine by two rear-admirals, one of them, M. Jurier de la Graviere, being a member of the late Council ; the other is M. Clouet ; the department of agri- culture by M. Tisserand, Director of the National School of Agriculture, and M. Herve Mangon, a member of the Institute and president of the Meteorological Society of France. The Academy of Sciences is represented by four members, carefully selected, viz., M. Dumas, the perpetual secretary, who is to be appointed president, and M. Liouville, the celebrated geometer, and two astronomers, M. Faye and M. Mouchea, both of them members of the Section of Astronomy. It must be noted that the Council of the Observatory, although vested with the right to present to the minister two candidates for the directorship of that establishment, are not to interfere with the solution of technical questions. A special council composed of all the astronomers en titre of the Observatory, are to meet once a month to solve them with the director of the Observatory. The first meeting of the Council of the Observatory took place on April 24, M. Dumas being in the chair. The members had been summoned in order to send to the Ministry a list of two candidates for the direction rendered vacant by the demise of M. Leverrier. The meeting was very short, and the members having been unable to agree, it was postponed to the 26th, when M. Faye wished to deliberate on the vexed question of the separation of meteorology and astronomy. This, however, was not allowed, when M, Faye protested and declared that he would bring the question before the Academy of Sciences at its next meeting, on April 29. After several scrutinies the Council decided to send in the names of MM. Mouchez, Loewy, and Tisserand as their nominees for the directorship of the Observatory, the last two having obtained an equal number of votes. Such was the result of the deliberations of the Observatory Council, which on the whole seem to have been conducted with becoming dignity. At Monday's sitting of the Academy, M. Dumas simply read M. Bardoux's letter, and summoned a meeting for to-day of a Committee of the Academy composed of all the sections in the mathematical sciences. A list of candidates will then be formed for proposal to the whole Academy, which will vote its candidates on May 5. It then remains with the Government to choose between the candidates proposed by the Council and Academy. M. Faye made no protest at the Academy meeting on Monday, though, our correspondent writes, he was expected to speak on the subject in a secret committee which met after the meeting of the Academy. We trust that throughout these important steps for the appointment of a successor to Leverrier all personal feelings will be suppressed, and the interests of the Observatory and of science alone considered. SOCIETIES AND ACADEMIES London Royal Societ}', February 7. — "On the Diurnal Range of the Magnetic Declination as recorded at the Trevandrum Obser- vatory," by Balfour Stewart, LL.D., F.R.S., Professor of Natu- ral Philosophy at Owens College, Manchester. The Observatory at Trevandrum was supported by His Highness the Rajah of Travancore, and its director was Mr. J. A. Broun, F.R.S., who has recently published the first volume of the results of his labours, giving the individual observations of magnetic declination, and deducing from them conclusions of great scientific value. Amongst the other results published by Mr. Broun, are the diurnal ranges of the magnetic declination at Trevandrum for each civil day in the eleven years, 1854 to 1864. In one respect the treatment of the declination observations at Trevandrum differs from that pursued at the Kew Observa- tory, inasmuch as in the former place, where disturbances are little felt, the diurnal ranges are from all the observations. Variadons cf Long Period. In order to investigate the long-period variation of the Tre- vandrum declination-range, I have treated these observations pre- cisely in the way in which the Kew declination-ranges were treated {Proc. Roy. Soc., March 22, 1877). By this method proportional values of the declination-range at Trevandrum have been obtained corresponding to weekly points for each year, and it is believed that these values are freed from any recognised inequality de- pending either on the month of the year or on the relative posi- tion of the sun and moon. If this method should be found to furnish nearly the same results in the case of two observatories so widely apart as Kew and Trevandrum, and with such marked differences in the annual variation of the declination-range, we may conclude that this separation of inequalities has been suc- cessfully accomplished. The proportional numbers have'next been dealt with precisely in the way in which the corresponding numbers were dealt with in the case of the Kew Observatory, that is to say, a set of nine- monthly values of declination-range have been obtained corre- sponding to similar nine-monthly values of spotted solar area. The results of this treatment are exhibited in the diagram which accompanies this paper. In Fig. I we have a curve representing the nine-monthly values of spotted area. In Fig. 2 we have the . Kew and in Fig. 3 the Trevandrum declination curve represented by nine-monthly values of the pro- portional numbers. In Fig. 4 we have a curve representing the mean between the proportional numbers of Kew and those of Trevandrum. From these figures it will be seen that a lagging behind the sun is a feature both of the Kew and the Trevandrum curves, while generally the prominent points in the Kew and Trevandrum curves agree well together in point of time. On the whole it would appear that by taking the mean of the proportional numbers for the two stations, we get a ^curve that represents the solar curve better than one derived from a single station. The whole period compared together represents both foe the solar curve (Fig. i) and the mean curve (Fig. 4), a series of three smaller periods, one extending from B to C and embracing the maximum ; another extending from C to c, and a third from c to e ; and this is as far as the observations common to both stations allow us to go in point of time. It may be of interest to compare, by means of the tables, the period between the solar minimum of 1855 and that of 1867, with the period between the corresponding declination-range minima. The first of these declination minima occurred at Trevandrum (the 26 NA TURE \_May 2, 1878 Kew observations not having then begun) on February 15, 1856, and the second of them occurred at Kew (the Trevandrum ob- servations having been discontinued) on August 15, 1867. The period is thus one of eleven years and six months. On the other hand, the sun-spot period is that between Sep- tember 15, 1855, and March 15, 1867, being likewise eleven years and six months. d. Variations which seem to defend on Planetary Configurations, In a paper on the Kew declination-range already alluded to, it was shown that the planetary periods of most frequent occur- rence appear to be well indicated by the results of sixteen years observations. Indeed, for the two periods of shortest length — that of Mercury about the sun, and that of Mercury and Jupiter, it was found that half of the observations gave a result of the same character as the whole sixteen years. From this we might conclude that these periods will probably (if they have a real existence) be indicated by the Trevandrum observations. It will be seen from the following tables that the Trevandrum declination-ranges give results for these two planetary periods very similar to those given by the Kew observations. ,7ront3 .1' Period of Mercury about the Sun. (0° denoting Perihelion— 65 sets for Kew— 47 for Trevandrum.) Between 0 0 Kew. Trevandrum 0 and 30 + 429 + 263 30 »» 60 + 433 + 223 bo >> 90 +256 + 237 90 )> 120 + 5 + 300 120 >» 150 -280 + 150 0 Q Kew. Trevandrum Between 150 and 180 -439 -433 „ 180 210 -413 -879 „ 210 240 -279 -740 » 240 270 — 140 -263 270 300 + 13 + 333 « 300 330 + 158 + 680 ,. 330 360 + 278 + 506 May 2, 1878] NATURE 27 Period of Conjunction of Mercury and Jupiter . (0° denoting Conjunction — 62, sets for Kew — 43 sets for Trevandrum. ) Kew, Between o 30 60 90 120 ISO 180 210 240 270 300 330 and 30 60 90 120 ISO 180 210 240 270 300 330 ■^60 + 633 + 759 + 652 + 328 -119 -S04 -678 -677 -548 -322 — 10 + 343 Trevandrum. + 453 + 270 + 129 -118 -384 -467 -487 -407 — 122 + 223 + 415 + 503 Zoological Society, AprU 16.— E. W, H. Holdswortli, F.Z.S., in the chair. — Mr. Sclater exhibited and made remarks on a typical specimen of the new fox lately described by Mr. Blanford as Vulpes canus, from Baluchistan. — The Secretaiy exhibited, on behalf of Mr. A. Anderson, F.Z.S., a bamboo stick with leather thong attached to it, such as is used in India for driving" plough-cattle with, which had been taken out of a uest of the common Fish Eagle {Haliaetus leiicoryphus), in December, 1876. — Prof. Westwood communicated a memoir on the Uraniidas, a family of lepidopterous insects, with a synopsis of the family and a monogi-aph of one of the genera, Coronidia. These insects were remarkable for their extreme beauty and the difficulty w^hich had attended their systematic classification. Their relations with other gi-oups of lepidopterous insects were discussed at considerable length, and their nearest affinities were shown to be with certain other moths belonging to the great division of the Bombyces, whilst their connection with the Hesperian butterflies, the Pseudo-sphinges, Erebideous Nocta; and Ourapterygeous Geometre was disproved by their general structure, the venation of then- wings and their transformations. A synopsis of the species of all the genera was given, and a complete monograph with figm-es of the genus Coronidia. —Mr. Gwyn Jeffi-eys, F.R.S., F.Z.S., read the first part of his work on the MoUusca, procured in the expeditions of H.M. S.S. Lightnitig and Porcupine. It would be recollected that these expeditions immediately preceded that of H.M.S. Challenger, but were restricted to portions of the North Atlantic, including the Mediterranean. The Brachiopods formed the subject of the present paper. A table of all the Brachiopods known to. inhabit the European seas was given, comprising ten genera and twenty-two species, of which latter four \\ere for the first time described and six figured. The table also particularised the geological and bathymetrical range of all the species. Two plates accompanied the paper, and were furnished by Mr. Davidson.— Mr. G, E. Loder, F.Z.S., exhibited and made remarks on a mounted head of the Rocky Mountain Bison, remarkable for its soft, dark, and long hair on the forehead. This specimen had been obtained near Denver, Colorado.— A communication was read from the Marquis of Tweeddale, F.R.S., containing the eighth of his contributions to the ornithology of the Philippines. The present paper gave an account of some Luzon birds in the Museum at Darmstadt, which had been sent to him for examina- tion by Prof. Koch of that place. — A communication was read froni Dr. O. Finsch, C.M.Z.S., containing description of a new species of finch from the Feejee Islands, which he proposed to \\sxae Amblynura kleinschmidti 3.itev Mr. Kleinschmidt, by whom it had been found in the interior of Viti-Levu. — Dr. M. Watson read a paper containing a description of the generative organs of the male spotted hysena (Hycena crocuta), and a detailed com- parison of them with those of the female of the same animal. — Messrs. Sclater and Salvin read a report on the collection of birds made during the voyage of H.M.S. Challenger at the Island of Juan Fernandez, at various points along the coast of Patagonia, and at the Falkland Islands. — A second paper by Messrs. Sckter and Salvin gave descriptions of three new species of birds from Ecuador, proposed to be called Buarrcmon leucopis, Neomorphus radiolosus, and Aramides calopterus. Wellington, N.Z. Philosophical Society, August 18, 1877.— After the con- firmation of the previous meeting's minutes, and the announce- ment of Mr. B. T. Chaytor and Mr. Robert Govett as newly elected members, the President (Mr. W. T, L. Travers, F.L.S. , M.H.R. ), read his paper on remarks as to the cause of the warmer climate which existed in high northern latitudes during former geological periods. This paper was a review of the pro- gress recently made in our knowledge of the subject, and espe- cially the bearing of Naysmith and Carpenter's examination of the moon's surface, and the work by Mr. Mathieu Williams on the " Fuel of the Sun." The author adopted the view that the gradual condensation of water on the earth's surface, consequent on the loss of its original cosmical heat, had produced the succession of phenomena resulting in the present distribution of life ; that in consequence of the cooling having taken place first in the polar regions, it was there that the higher and latest- formed organisms must have first appeared. He adduced as proof of this the existence of fossilised vegetation within the Arctic regions which had almost a tropical character, and other evidence that during successive geological epochs the changing character of the fauna and flora in other regions showed that the climate had gradually become more and more temperate. Dr. Hector would only speak as regards the geological aspect of the author's paper. The fact that the oldest rocks we know are either hydrated or formed by the action of water as sediments proved that our geological records did not carry us back to a time when very high temperature prevailed. It was only, there- fore, necessary to inquire into the evidence of a minute secular cooling afforded by the succession and distribution of animals and plants during former epochs. He considered this evidence very unsatisfactory, and not leading in the direction the author required. The former existence of temperate plants in high latitudes took place at a very late period in the earth's history, and long after some temperate regions had possessed a fauna and flora similar to that at the present time. There had, in fact, been several repetitions of the abnormal distribution of animals and plants on which the author founded his argument, and consequently of the climate; so that these changes could hardly be referred to the progressive cooling of the globe as a whole. The inferences made had chiefly been drawn from late tertiary strata, but inthe case of Nev/ Zealand there was evidence that the same type of vege- tation had survived since the early part of the cretaceous era, a period twenty times as great as that which had elapsed since the supposed sub-tropical fauna inhabited Central Europe, or the temperate flora flourished in the Arctic regions. From this it was surely to be argued that the cause had not been one ot liniversal operation. Concerning the former Arctic flora the real difficulty was not the question of temperature so much as the absence of light m that region for six months of the year if all other conditions of the earth remained as at present, except a general higher surface temperature. Many speculations had been put forward on this subject; one of the latest, by John Evans, was that the earth was solid with an oxydised crust, separated from the central nucleus by a viscous layer of unequal thickness in which chemical combination, or, as it may be called, the "rusting process," was still active. The elevation of mountain masses by the fracture of the crust would act like weights on a gyroscope and lead to a gradual displacement of the outer crust with reference to the axis of rotation of the interior bulk of the earth, which astro- nomers required us to believe to be immovable. He also pointed to recent researches of Prof. Duncan regarding reef-building corals, which at the present time are confined to a narrow equatorial belt, but in eocene times that belt appears to have had a distribution oblique to the present equator. If this were established it would offisr a still greater difficulty in the way of accepting the view that the changes in distribution of climate were due to the secular cooling of the earth as a prime cause. Mr. Carruthers thought it not yet proved that there was a central heat, and certainly not that it could influence climate. He thought the balance of evidence was against the theory of central heat. If the earth had once been hotter it would have become smaller in cooling, and its velocity of rotation would have increased ; but this was con- trary to fact, as the rotation had been retarded by about three hours since exact observations were first made. With regard to what had been said about the thickness of the earth's crust, the exist- ence of tides proved that it must be so great as to be absolutely rigid. He considered it quite possible for plants to live in darkness if they remained dormant, like geraniums, which are placed in a dark cellar during the winter. September i, 1877. — Mr. W. T. L. Travers, president, in the chair. — Mr. Coleman Phillips read his paper on a peculiar method of arrow propulsion as observed by the Maoris. The author gave an interesting description of how 28 NATURE [May 2, 1878 the arrows were thrown by means of a string, which he illustrated before the meeting with a model. He expressed sur- prise that, as far as he was aware, nothing was known of the bow among the Maoris, a weapon so commonly used by natives of other islands. Mr. Grace, who had been in New Zealand from his youth, said that the bow and arrow was a common weapon in the interior with the Maori youths, and he believed that it was originally used by the natives. It was, however, found by them to be an inconvenient weapon in the bush, and hence their reason for adopting the plan mentioned by Mr. Phillips. The Maori scarcely ever threw a spear by hand ; they used the string twisted round a fork in the spear. The notch mentioned by the author was new to him. — The President read a paper on grasses and fodder plants by Dr. Curl, being a con- tiiiuation of a paper by the same author read last year, and printed in vol. ix. of the Transactions. — Mr. Carruthers read a paper on a system of weights and measures, in which it was pro- posed to change the radix of counting from 10 to 16, and to adopt the latter number as the radix for all weights and measures. Philadelphia Academy of Natural Sciences, November 13. — The agri- cultural ants of Texas, by Rev. H. C. McCook, — On a stone axe, by Mr. J. Ford. This was found in a bluff fifty feet above the level of the Mississippi, and embedded twenty feet deep in solid limestone, without fissure or crevice, giving evidence of great age. November 27. — Remarks on American species of Difflugia, by Prof. Leidy. — On the aeronautic flight of spiders, by Rev. H. C. McCook. Vienna Imperial Academy of Sciences, February 7. — "Mono- graphia Pulmonariarum," by M. Kemer. — On bixin, by M. Etti. — A centrifugal air- ship, by MM. Szigyarto and Kuczera. — On the originals of v. Bom's Testaceis Musei Caesarei Vindo- bonensis (1780), found in the Imperial Zoological Museum, by M. Brauer. — On new neuroptera, by M. Steindachner. — On a peculiar spinal cord band in some reptilia and amphibia, by M. Berger. February 14. — Construction of tangents at the contact line of a rotation surface and the developables described outwards and round it from a point, by M. Drasch. — Completing additions to the general mode of determination of the focus of contours of surfaces of the second degree, by M. Pelz. — On the action of bromine on phenoldisulphoacid, by M. Schmidt. — On the pro- ducts of decomposition of a gum-ammoniac of Morocco by melting hydrate of potash, by Dr. Goldschmidt.— Telephone signalling apparatus, by M. Puluj. Rome R. Accademia dei Lincei, February 3. — New researches on the ossiferous caves of Liguria, by MM. Gasteldi and Ferroti. — Discovery of arms of stone and bronze in Calabria, by M. Ruggeri. — Geological and palseontological studies on the middle cretaceus of Southern Italy, by M. Seguenza. — On benzylic santonate, and on tribenzylamine and its chloroplatinate, chlorhydrate, sulphate, alum, and nitrate, by M. Panebianco. — On the new anomalous anastomosis between the trochlean nerve, the supra-orbital and the sympathica cavernosa, by M. Berte. — New general theorem of mechanics, by M. Cerruti. Paris Academy of Sciences, April 22. — M. Fizeauin the chair. — The following among other papers were read: — Researches relative to the action of dry oxalic acid on primary, secondary, and tertiary alcohols, by MM, Cahours and Demar9ay. This is in completion of a former study (C. R. vol. Ixxxiii. p. 688). The experiments were made with methylic alcohol, primary and secondary octylic alcohol, trimethyl-carbinol, and dimethyl ethyl-carbinol. The action of dry oxalic acid on tertiary alcohols, which consists in splitting them into hydrocarbons and water which unites with the acid, establishes a very marked distinction between them and primary and secondary alcohols, which, in like circumstances, are transformed always into oxalates. — Report on a memoir by Lieut. Pinheiro of the Brazilian navy, on a sondograph. This instrument is for giving information regarding banks in rivers. A wooden rod is fitted at its lower end with a hollow roller to roll on the bottom and collect small portions of the material ; at the top it is articulated round a horizontal axis carrying a graduated arc (which shows the various mchnations) and also a toothed wheel, which, though a pinion and eccentric, gives a straight motion to a style, tracing a continuous curve on a moving band of paper. — M, Gaiffe exhibited a manometric safety steelyard. It is mounted on steel pivots, and connected with a piston having ten square millimetres of surface. It indicates with pre- cision the pressure of the boiler. Annexed is an alarm whistle communicating with a valve box by a graduated rod. — A letter from M. Andre was read, announcing the arrival at Ogden, Utah, of the party sent out to observe the transit of Mercury. The U.S. Government laad given them the use of the nearly finished observatory at Ogden, and any instruments they wished ; the photographic instruments used by the Ameri- can Venus transit expedition were put in their hands. A tele- graph wire connects Ogden with Washington. — Observations of solar spots and protuberances during the first quarter of 1878, by M. Tacchini. The number of spots has continuously diminished since the beginning of last year, so that the minimum appears to fall, not in 1877, but in 1878. The protuberances, too, have been very few and small: 2'l on an average daily, with a height of half a minute ; they occupy only 3*5° of the solar limb. In distribution they extend over a large zone, but with the peculiarity of two characteristic maxima beyond the principal zones of spots, i.e. between 30° and 60° in both hemi- spheres. The nebulous structure predominated. There were no isolated metallic eruptions. — On observations of Mercury, made at the end of last century, by Vidal at Mirepoix, by M. Bigourdan. These are shown to be as accurate as was possible with the means at Vidal's disposal. — Results of experiments made at various points of Algeria, in industrial use of solar heat, by M. Mouchot. The reflectors he finds best are made of a plate of silver, or brass electro -plated with a thin layer of silver. At Algiers the heat received per minute by his solar boiler was 7 calories in April, 8 in May, and 8*5 in June and July. M. Mouchot tabulates the results obtained in various localities ; they range from 9*8 cal. to 5. — On a large fossil reptile [Eiirysattrus raincourti), by M. Gaudry. The remains of this were come upon by workmen in a quarry near Vesoul, as far back as 186 1. A Dr. Gevrey happened to pass and brought some of the blocks of bone to Vesoul, where they have been forgotten seventeen years. The Marquis de Rain- court having seen them perceived their interesting nature. The remains are estimated to have covered a space five metres in length. The animal has affinities to the plesiosaurians, but it is not a true plesiosaurus, for its head is so heavy and its teeth are so large that it could not have had a very long neck. The cervical vertebras, too, are narrower and convex behind. The cranium was flattened and the teeth weie directed outwards. The nostrils must have been placed far back. CONTENTS f. Page Retrospect and Prospect. By the Editor 1 The American Storm Warnings. By Jerome J. Collins .... 4 Newcomb's Astronomy. By J. R. Hind, F.R.S 7 Slate and Slate Quarrying 10 Our Book Shelf:— Hulme's " Familiar Wild Flowers " 11 Geographical Books n Letters to the Editor: — The Telephone. — George S. Clarke ; Herbert McLeod . . . ii Poisonous Australian Lake.— George Francis . 11 Transmission of Vocal and other Sounds by Wires.— W. J. Millar, C.E 12 Westinghouse Brake. — R 12 The Oxford Commissioners' Statement. — B 12 Contact Electricity. — J. Brown 12 Solar Halo. — E. Rodier 13 Floating Magnets. By Sir William Thomson, F.R S. (JVith Illustrations) 13 A Rotating Book-Case (fJ^zV/z/Z^^/m^/^jw) .....'. '. .' ] 15 Faustinus Jovita Marianus Malaguti 15 Dr. Thomas Thomson, F.R.S. By Rev. M. J. Berkeley .... 15 The Greenland Eskimo. By A. Bordibr {With Illustrationi) . . 16 PozzoLANA Mortar and Pine Timber 19 Stanford's Stereographical Map of the British Isles .... 19 Our Astronomical Column : — Transits of Mercury 19 Kepler's Manuscripts and Relics 20 The Pulkowa Library Catalogue 20 Geographical Notes : — Round the World 20 Africa 20 Notes 20 The University of Oxford Commission 23 An Improved Method of Projecting Lissajous' Figures on the Screen. By J. Dixon Mann, L.K.Q.C.P. (^^zM ///«j/m^w«) . . 24 The Paris Observatory 25 Societies and Academies {With Illustration) 25 NA TURE 29 THURSDAY, MAY 9, 1878 PHYSICAL SCIENCE FOR ARTISTS I. WE have it on the high authority of Lord Beacons- field that the Enghsh School of Artists is arriving at a pitch of unexampled excellence, and that English art is in the future to be the cynosure of an admiring world. It is Lord Beaconsfield's opinion that the time has arrived in which we may speak of a school which has flourished for a century with some accuracy of deduction as to its principal features. The principal features of the English school are, he thinks, now recognised. "All will admit that it is a school of great originality. All will admit that, in some provinces of painting, it has certainly estabHshed a reputation which may be rivalled by some nations, but which can be sur- passed by none. Its power of portraiture is recognised in the most classic galleries. As far as landscape painting is concerned, it has achieved the highest aim of both branches of the art — whether ideal, like the en- chanted castle of Claude Lorraine and the classic groves and solemn temples of Poussin, or whether it has com- peted with the freshness of Hobbema or Ruysdael, English art can match the chefs d^oeuvre of every country." This is high praise, and we may gather from it that so far as the reproduction of form and colour goes our artists have arrived at the highest knowledge and skill. Of late years also, we are told, the English school has given an indication of aiming at a higher range of imaginative composition than has hitherto prevailed; and this Lord Beaconsfield holds is natural, because if there is an imaginative nation in the world it is the English nation. " It is the nation that has produced the greatest number of poets — the greatest number of illustrious poets — and, therefore, the British artist has a heritage of imagination which ought to be to him a fund of inspira- tion." Nor is this all. "He has also another advantage which no great school has yet possessed — he has a larger range of subjects. What the pictures of antiquity were we know very little. We know very well that Zeuxis painted a curtain that deceived his patron, but if that were a test of his school it might, I believe, be stood by the commonest scene-painter of the nearest theatre. With regard to the Italian masters, we know their admirable works abound ; they established, not one school, like England, but many schools. Those schools produced many pupils, and their prolific works charmed and in- structed the world. But if you look to the great creations of the Italian schools, you will find, generally speaking, as far as subjects are concerned, their range was extremely limited. They drew their inspiration from two religions — the Christian and the Pagan ; and every one must feel^ when he examines a gallery of Italian art how much it is to be regretted that such genius and power should not have commemorated the great acts of their own history. . . ." Under these circumstances Lord Beaconsfield takes a very favourable view of the English school. He believes that "there is a feeling which will not be satisfied in the works of art if art does not aim at the production of the highest modem style of imaginative creation." That our artists Vol. xviii. — No. 445 will shine here the noble speaker is convinced. " I rely on the fact that there never has been a limit to the increasing excellence of English achievement when a fair and just opportunity was offered to it ; and, therefore, I do look forward to a period of which, I think, we have many symptoms and encouraging circumstances about us, when imaginative art will be characteristic of the English school, as well as that sense of humour and that exqtdsite feeling of nature and intellectual delineation of portraiture to which I have before referred.' ' The result predicted by Lord Beaconsfield is of course a consummation devoutly to be wished, and if it be true that Art is Nature passed through the alembic of Man, then this highest style of imaginative creation should largely increase the number of students of science in this country, because, although Lord Beaconsfield was careful not to say too much about Nature, she is there all the same, and the laws which underlie the phenomena which it is the function of art to embody should, at any rate* possess some interest to the artist, and if he is to surpass Nature, he must not hope to do this by evading her. In art as in science, imagination must have a basis to work upon, and the surer the basis the more will the imaginative effort which transcends it be in sympathy with those hidden powers of the mind and those hidden feelings which it is the function of art to bring into play. What little I know of the history and development of art would seem to show that in the early days at all events the artist was second to none in his appreciation of the science of the time. Geometry was rapidly applied to perspective, anatomy to form, and although the dwellers in Italy had the finest examples of ancient art to appeal to, it is not difficult to trace the rise of such men as Leonardo da Vinci and Michael Angelo to the direct influence of the study of anatomy first introduced at the University of Bologna. Da Vinci was, as is well known, almost as famous for his knowledge of science as for his productions in art. Indeed the anatomical studies carried on in the wonderful medical schools of Italy during the Middle Ages may be said to have left a greater mark on the world from an art point of view than they have done in the domain of the science of surgery. Galileo, when he took so large a share in founding the physical science of to-day, was a student of medicine ; the wonderfully regular swing of that famous lamp at Pisa suggested to him in the first instance a method of observing the flow of blood through the veins. The idea that here was a perfect method of dividing the flow of time — the idea of the pendulum clock — did not come till afterwards. Still the teaching of the medical school was no more to Galileo than it had previously been to Leonardo da Vinci or to Michael Angelo. Now what is the condition of things to-day? We might be in the same position with regard to physical science — the science of colour — as Da Vinci and his con- temporaries in the 15th century were with regard to biological science — the science of form. The whole range of physical science — a branch of knowledge which has existed for two-and-a-half centuries, but which has lately been developed enormously precisely in those directions of the greatest value to the artist, has not yet been annexed by the students of art. So far as I can see there is not among artists gene- c \o NA TURE [May g, 1878 rally— among those 'even who acknowledge their obli- gations to mathematical and biological science in the regions to which I have referred — the notion that they have anything to learn from physical science — physical science being reduced, at all events it will be convenient that in what I now say I shall take it as reduced, in the main, to optics. There seems to be a sort of notion that there are no laws underlying the phenomena of air, and sky, and sea; that while the shape of a horse's leg is de- fined by law, the order of colours, for instance, in a rain- bow, depends upon the play of blind chance. Indeed I have been informed — and I may tell the story here because it hammers my point home better than anything I could say — that an eminent artist, now living, who had painted a rainbow practically inside out, when the pic- ture was returned to him in order that the colours might be corrected, was so indignant with this attempt to interfere with this special development of the " highest style of imaginative creation," to use Lord Beaconsfield's words, that he charged the trifle of 20/. for attempting to place the colours in the order in which monotonous nature perversely insists they shall stand. This is a general attitude, not only of artists, but of would- be teachers of art, and these latter piteously make tempting officers of the whole range of theology for science to work her wicked will upon, if only art may be spared from her contaminating touch. This is not, however, the universal attitude, as I can abundantly testify. Some of our modern painters do most enthusiastically enter into the - study of physical science not only for its own sake, but . in order to embrace it in their art. It has been my great privilege during the last few years to discuss with painters of the highest eminence questions bearing on art which have arisen from my own investigations in another region of woi'k, and in the study of which the works and obser- vational powers of the artist have been of the greatest value to me. It is as a result of these many conversations that I have determined to put on paper a sketch of some of the many points in which I think the interest of the operation of nature' s laws is as great from an artistic as from a scientific point of view. I shall, I hope, be able to throw these notes into order, but I shall content myself at first with giving an idea of the result of such studies upon art criticism. Whole reaches of art will remain untouched by physics, and its influence will be chiefly felt by the land- scape-painter. It is only those who are ignorant of the de- velopment of art who will look with suspicion upon the new tests of truth with which artists can supply themselves — with the new ways of tracing effects to causes. Art criti- cism must gain considerably, for in place of jargon we may in time find common sense, and when once this basis is secured then the more secure will be the "highest style of imaginative creation" resting upon it. I shall best indicate what I believe will be the influence of the study of optics in the future on art, by stating, by way of introduction, in its most naked form the result of an appeal to the newest branch of knowledge as a test of the truth to nature of several of the pictures in this year's Academy. The recent results obtained by the workers in spectrum analysis have added so much to our former knowledge of the actions which go on when light is given ou":, or re- flected, or absorbed, that almost all the optics the painter really requires conveniently lies round the most recent work in molecular physics, for the reason that it is the action of molecules which builds up the world with which the artist has to deal. The instance I shall take in this paper is the following one. One of the smallest of the developments of the new branch of optics supplies us with facts which can be embodied in a simple working hypothesis. The approxi- mate truth of this can be brought to the test by the various colours of the sky. When I say "working hypothesis," I use a term well known to men of science to indicate a train of thought to work upon and test. It is a first approximation to a general grouping of many facts, and it is perhaps as much generated by imagination as by work. It is not a hypothesis in the ordinary sense of the word, because it has not borne sufficient tests, and it especially is not a thing to be dogmatic about (and by this I do not mean to imply that there is anything whatever which ever should be) but still I think it will serve my turn. Although I have never painted a picture, and am no art critic, yet I have criticised the pictures in this and former years with the most intense pleasure from the scientific point of view. This year I have limited myself to sky colour, and I have prepared two lists, one, including those pictures which I think in harmony with nature, and the other those which represent pheno- mena which, however probable in any other planet, are, I think, physically impossible in this. I have done more. I have tested the hypothesis by the pictures. I have gone over those in which I was chiefly interested from my narrow point of view with two artist friends of great distinction, and I have asked them whether the view at which I have arrived in each case was correct. The test I had applied had failed me in no instance. Here then are the most salient examples included in my lists. I dealt with pictures, not artists, and carefully avoided seeking the artist's name in any case ; but here I must bring them out, in order to refer to the pictures with sufficient completeness. First, then, to deal with those pictures in which cloud and sky colour are, I think, correct : — 3. " The Timber Waggon " — C.E.Johnson. Accu- rate study of the absorption of light by a slightly hazy atmosphere. 62,. "A Summer Flood" — H.R.Robertson. Colour of cumulus clouds glowing with the reflected light of sunset, perfect. 105. " The Cornish Lions " — John Brett. Remarkable picture : the colours and the atmospheric absorption, and therefore transformation of the colour, perfect. 153. "Evening" — R. C, LesUe. Wonderfully true rendering of a very rare effect, 230. "Estes Park, Colorado, U.S."— Albert Bierstadt. Very fine atmospheric study. The vapour roUing down the valley leaves its effect on the picture marvellously. 267. "Wandering Shadows"— P. Graham, A. Mag- nificent picture. Notice the effect of the atmo- May 9, 1878] NATURE 31 sphere laden with aqueous vapour on the colour of the hill in the background. 268. "The Alps at Rosenlaui "— V. Cole, A. Glo- riously true. The fading of colour in the distant bosses is perfectly rendered — the depth of the atmosphere can be gauged. 306. "Struyve Rocks, coast of Arran" — Geo. E. Hering. A red sunset, nearly perfect in colour from top to bottom ; if the yellow had faded into green it would have been better. Compare red with 353. 324. "Conway Marsh" — Jos. Knight. Sunset green, and deep blue hill admirable, but I doubt the colour of the foreground. 405. "Gleaners" — H. R. Robertson. Red, yellow, green, good. Moon nearly right, which is wonderful. (This by the way). 587. "Shining after Rain: Loch Etive"— Geo. E. Hering. The work of a careful observer. 615. "The Lowing Herd winds slowly o'er the Lea" — H. W. B. Davis, R A. Perfect sunset (poor moon !). (Again by the way). 647. " An Autumn Walk " — A. E. Emslie. Good red and yellow. 739. "Sunset on the Jungfrau, Monch, and Eiger " — Jas. W. Smith. The blue below and red above on the snow perfectly rendered. 788. "The Written Valley, Wilderness of Sinai" — Henry A. Harper. Good, but not so good as 739. I next come to those pictures which I think are inac- curate in colour. 86. "Christiana with her Family, accompanied by Mercy, arrive at the Slough of Despond : Mercy finds a way across"— R. Thorburn, A. Im- possible cloud colours. Clouds bluer than sky and atmosphere nowhere. 146. "Solitude"— P. F.Poole, R. A. Impossible green sky and cloud. 201. B. Riviere, A. Unnatural moonlight and im- possible pea-soup shadows. The softness and colour of the latter suggest that Mr. Riviere has never studied moonlight. 231. "David, the Future King of Israel, while a Shepherd at Bethlehem "—J. R. Herbert, R.A. Colour impossible both in quantity and quality. 240. "A Dream of Ancient Egypt : the Morning of the Exodus " — Andrew MacCallum. I should like to hear the painter lecture on the con- nection of the colours of bodies with the light which falls upon them. 298. "Jarl Hacoi in the Pentland Firth"— J. Hope •M'Lachlan. High blotches of red over green and yellow impossible, and brick-dust beams of light proceeding from nothing still more im- possible. 309. " The Sunrise Gun, Castle Cornet, Guernsey " — Tristram Ellis. Sky colour good ; impossible colour of water under sky conditions given. 353- "After the Rain"— W. H. W. Foster. Un- natural sunset, colour and distribution of light 424. "The Last Journey" — Clara Montalba. Impos- sible green sky ; the sun is neither setting nor set. 483. "An Autumn Sunrise " — Cecil G. Lawson. Interesting as a foretaste of the future when the sun shall have cooled. 525. A. Dixon. Green hopelessly wrong. 542. "The Dee Sands "—J. W. Oakes, A. Sky colours impossible with so high a sun. 555. "The Last of the Wreck"— E. Ellis. Green clouds ! 630. " An Incident by the Wayside " — Mark Anthony. Impossible blue sky. These, then, are the pictures I shall use as texts in my future notes. J. Norman Lockyer THE AMERICAN STORM WARNINGS'- I HAVE now to direct attention to "Atlantic Storms,— Whence they come and where they go?" All storms that cross the Atlantic Ocean to the coasts of Europe come from the equatorial zone of the Atlantic from the Pacific Ocean, or are developed from depres- sions on the American continent by peculiar operations of the law of atmospheric movements. The most prolific source of storms for the field of observation just sketched is the Pacific, but all the disturbances coming thence do not necessarily originate there. As I have stated, storms pass over the Pacific from the Asiatic as they do from the American continent over the Atlantic, but generally in more northerly latitudes. Their num- ber cannot be accurately determined until a similar system of observation to that now in operation from the West Indies to Newfoundland is organised on the Eastern coast of Asia. As it is we are dependent on observations made along the Pacific coasts of the United States, British territory, Mexico, and the Central American States, for information regarding the arrival of storms from the westward on this continent. Fortunately the observers are now numerous enough to constitute an effective guard against the possibility of even a small storm centre passing inland unnoticed. These coast observations furnish reliable evidence of the fact that storms arrive on this continent from the Pacific much in the same manner as Atlantic storms reach Europe. It is my purpose to trace as closely as possible the move- ments of the various types of storms that originate in or cross the Atlantic from west to east,' and I will begin with those whose first appearance is observed on the Pacific coast of the United States. It has been noticed that storm areas approach these Pacific coasts as large depressions with a comparatively low energy of rotation around their centres. But when the area reaches the line of the coast or cascade range of mountains in Oregon and Washington territory, its outline is changed from the distorted circular to that of the irregular elliptical, and the northern end of the latter figiure is carried toward the coast line more rapidly than the southern one, causing, as a rule, the first rainfall in the line of first contact with the land. Therefore, over Vancouver's Island and Western Oregon a rapid con- densation of atmospheric moisture takes place which so ' Continued from p. 7. 32 NATURE l^May 9, 1878 speedily exhausts the air volume immediately affected by the storm of its humidity, that the lines of equal annual rainfall on this section of the coast are very close together, marking a decrease of precipitation inland. The energy of rotation increases here as the pressure at the storm centre falls. This energy concentrates at the northern end of the depression, and the area of low barometer is drawn, as it were, around the centre so formed as it passes eastward over the first range of mountains. After passing over all the intervening ranges of the great plateau toward the line of the Rocky Mountains in Mon- tana and the British territory northward thereof, the storm as a moving atmospheric vortex is attended by only a very little rain or snow. TheVegion over which it passes cannot furnish any supply of humid air, and the storm becomes again disorganised into a great depression during and after its passage over the mountains, until its centre has reached the eastern slopes. But here it enters a new region so circumstanced in its topographical rela- tions Avith the east and south, as to derive a full and uninterrupted iiow of humid air from the great river valleys, the lake regions, and the distant Gulf of Mexico. There are no intervening mountain barriers between these sources of humidity and the north-western prairies to interrupt the atmospheric flow toward the depression extending over them, but the storm reorganises slowly at first as the conditions necessary to induce a strong in- draught of air to its centre are of very gradual develop- ment. When, however, they come into requisite combi- nation, the indraught winds increase, and coming from the north-east and east, are deflected southward and south-eastward by the mountains, until a feeble but decided vortex is developed in the centre of the depres- sion. The centripetal winds now begin to increase with the inflow of humid air, and the newly organised storm- centre moves eastward along its track, toward the region of the Mississippi Valley or the lakes. In doing so it descends the gradient of the plains through air of in- creasing density, and acquires greater energy every mile it advances. High pressures to the northward and southward of the storm-centre constantly feed it with fresh volumes of air, which being of different conditions of temperature and humidity, produce the rainfall that generally begins when the eastern margin of the depres- sion enters the Missouri Valley. In the great region of the plains the storm finds free scope for development as well as an unfailing supply of atmospheric moisture. It usually attains its greatest energy when passing over Iowa, Illinois, Ohio, and Kentucky, toward the Upper Ohio Valley, and the narrow neck of territory between Lake Ontario and the Pennyslvanian section of the Alleghany Mountain Range. This mountain wall in- fluences the course of the storm by deflecting it toward the north-east from the Middle Ohio Valley region, and thence over New England to Nova Scotia. The districts eastward of the Alleghany Mountains and southward of New York are rarely traversed by storm-centres coming as I have described, from the north-west, but receive the rainfall of the eastern margin of the storm as its centre passes north-eastward beyond the mountains, into the St. Lawrence Valley or the New England States. But the mountains cause a profuse rainfall on their western slopes, and when the storm reaches the Atlantic the precipitation has been nearly exhausted. Its energy, therefore, decreases, when crossing from Oswego to Portland or Eastport, Maine, and does not recover until it receives from the Gulf Stream Region a new supply of humid air. I have endeavoured to describe the course of a storm-centre from the Pacific to the Atlantic, across the Continent, and have made no detailed explanation of the relation to its movement of the areas of high pressure. This I regard as of the highest importance, and will treat of fully under a special head. The course of the storm across the Atlantic, as well as its movement over Europe, will be governed only, I may say, by the high pressures. These being distributed from south to north, in a series of continuous, but movable zones, mark the directions of the storm's advance so clearly, as to enable an observer at this side of the ocean to predict with general accuracy, the section on the European coast on which the storm- centre will arrive, as well as the time of its arrival. Another type of Pacific storm is that which arrives on the southern and central section of the California coast as a great depression, and entering the continent, pours its rains over California, and becomes divided into two sub-areas of low barometer by the Sierra Nevada range. One of these sub-areas, and nearly always the largest, takes a south-easterly direction across Southern Nevada, into Arizona, and crosses the Rocky Mountains in New Mexico to Northern Texas, where it is organised into a storm in the same manner, but much more rapidly, as the previously described area crossing into Montana. The other sub-area passes from Central California to Idaho, and thence across the Rocky Mountains, into the Yellowstone River Valley in Montana, pur- suing a track, thereafter, which sometimes brings the depression into the Lower Missouri Valley, but usually towards the Upper Lake Region. This sub- area of low pressure also becomes organised into a storm, but one of much less energy than that of Northern Texas. This can be accounted for by the fact that the crossing of the mountains by both sub-areas being almost simultaneous, the northern depression cannot receive any considerable atmospheric flow from the southward, as it is intercepted and drawn toward the southerly vortex. It sometimes occurs that the two centres of disturbance unite in a common depression west of the Mississippi River, but usually they preserve their identity, and become separated gradually by an inter- vening zone of relatively high barometer developed between them by their joint influence. The northern centre moves away to the north-east, over the lakes and Canada, with diminishing energy, but the southern storm centre advances into the Lower Mississippi Valley, and soon dominates th6 weather conditions over all the region southAvard of the lakes. In this position its isobars extend eastward to the Georgia coast, and even into the Atlantic, but the centre moves towards the Ohio Valley, westward of the Alleghany Mountains. The consequence is that a section of the depression near the Atlantic coast is cut off" by the high range of the Alleghanies, and another sub-area is formed which is speedily organised into a dis- tinct storm centre by the impinging of the ondraught winds from the east, north-east, and south-east on the mountains, in the same manner as I have already described. May 9, 1878] NATURE . ZZ f .. As the centre of the main disturbance moves up the great central valley the subsidiary centre east of the AUeghanies moves with it, and where the mountains decrease in elevation the two centres draw towards each other so as to have a common encircling isobar of 29"6o inches, and sometimes even less. When they reach the latitude of New York, storms of this type commonly leave the coast between latitudes 38° and 42°, attended by an area of high pressure imme- diately to the northward, and followed by one from the south-west. The courses of these storms across the Atlantic are generally in comparatively low latitudes, and they arrive on the British Coasts from the west or south-west with moderate rains and winds backing from the north-east to the north-west. Another type of Pacific storms is the one which originates in the tropical zone of that ocean, and strikes the Mexican coast, moving directly across that territory into Southern Texas, and along the Gulf Coast over Florida and Georgia to the Atlantic. The energy of such storms is frequently very great, and they retain, even after 'crossing the Mexican plateau, many of their original cyclonic features. When they move north- eastward through the Mississippi Valley they are always attended by heavy rains and electrical disturbances. Local storms or tornadoes are frequently developed on their south-eastern margins during the spring and sum- mer months, and are always very destructive. These Mexican storms, so called to distinguish them from the disturbances that move over Northern Texas from the California coast, will sometimes, but not often cross the Alleghany Mountains from Tennessee to Vir- ginia, and pass into the Atlantic northward of Cape Hatteras. Their courses across the Atlantic are gene- rally southerly as compared with those of storms leaving Nova Scotia. They arrive on the British and French coasts from the south-west, but are now and then carried in a north-easterly direction, passing to the Norwegian coasts northward of Scotland, and thence over the Scan- dinavian Mountains into North-Eastern Russia and the Siberian Seas, The cyclone, or great storm thatoriginates in the equa- torial zone of the Atlantic, by which I mean the region embraced between the equator and 15° N, lat., possesses characteristics which mark it as the most destructive atmospheric disturbance known to meteorologists. Of course these storms are developed in the equatorial zones of other oceans, but are not of such immediate interest to us as the Atlantic cyclones. I am convinced that the conditions which combine to develop nearly all areas of low pressure have an equatorial origin, the exceptional cases being due to local liberations of terrestrial heat during earthquakes and to the heating of volumes of air over great areas of sandy desert. North Atlantic cyclones may be divided into four classes, namely : Those that originate near the Cape Verde Islands and make their northward curves east of the 35th meridian, and do not affect the American coasts, but enter the European area over Morocco and Spain, passing eastward over the Mediterranean Sea. They are of comparatively rare occurrence. Secondly, those that originate about the 40th, and curve northward east of the 8oth meridian. affecting the American coasts only by the induced mar- ginal winds. Thirdly, those that originate immediately east of the Caribbee or Windward Islands, and perform their northward curves between the Both and 90th meri- dians, so as to pass through the eastern part of the Gulf of Mexico, and over Alabama, Florida, Georgia, and the Carolinas toward the North Atlantic. Fourthly, those that originate nearer to the equator than the others referred to, and make the tremendous sweep from the middle of the ocean between the Venezuelan coast of South America and that of West Africa, over the West Indian Islands to the Texas coast, and there curving northward and eastward, sharply pass over the southern sections of the United States and into the North Atlantic from the vicinity of Cape Hatteras. Of the first-named class of cyclones, little need be said beyond the reference already made. They represent the most serious dangers to be encountered by vessels bound to West African or South American ports, or passing over the Cape route to the Indian Ocean. The second class of cyclones, of which we have examples in the great storms of October 12, 1780, August 17, 1827, and August 12, 1837, and the later one as traced by the United States Signal Service Bureau, which commenced about August 18, 1873, take northerly courses. The only land station where these can be accurately observed is that at Bermuda ; therefore information regarding their energy and movements must be collected from the logs of ships that cross their tracks. It is believed that these storms are developed only in the midsummer, and are not of frequent occurrence, but on these points we have very little reliable information. I am, however, inclined to accept the statement as to their infrequency. The third class of cyclones we are more familiar with, because it embraces that type of equatorial storm which we most frequently experience. Examples from the earlier meteorological records are the storms of August 10, 1831, and October 6, 1846. With these we have the recent one of September 21, 1877, and which was signalled to London by the Herald Weather Biureau. The passage of this storm over the South Atlantic coast of the United States was attended by many disasters, wrecks, and inundations. Its course towards Europe was in compara- tively low latitudes until it approached the Bay of Biscay, when it moved sharply north-eastward, causing heavy gales and rains, with thunder and lightning. The latter effects were very marked in Scotland. The fourth class of cyclones, such as those of June 23, 1831, and September 27, 1837, and later on September 21, 1875, known as the great Galveston cyclone, are usually of extraordinary violence. Among the first successes of the Herald Weather Bureau was the correct prediction of the course of this storm when it was moving westward over the Carribean Sea. Only on one instance within my observation has a cyclone of the third class passed northward on the western side of the Alleghany Mountains, and then the storm exhausted its energy in Canada, but its depression, though much contracted, reorganised into a minor disturbance when it passed into the Atlantic, off the New England coast. The tendency of cyclones to lose their force by the extension of their area of low pressure is more decided than in any other type of storm. This will account for the low degree of 34 NATURE \_May Qf, 1878 energy in disturbances evidently of equatorial origin when they reach the Pacific coast of the United States and the coast of Spain. Unless the direction of the zone of high pressure along the south margin on which they move forms an angle of more than forty-five degrees with the equator, the storm has a tendency to pass through it, and in doing so expends much of its energy. Jerome J. Collins {To be continued.) GAS AS FUEL ATTEMPTS have been made from time to time to use gas as a means for heating ; these attempts hare more frequently failed than succeeded, chiefly by reason of the mechanical difficulties to be overcome. It is pretty generally agreed that, on account of the ease with which the supply of a gaseous fuel can be regu- lated, the completeness with which such a fuel can be burned, the comparative readiness with which cleanliness can be maintained while using this fuel, and by reason of its high heating power, and for other reasons, gaseous fuel is to be much preferred to fuel in the solid form. The most perfect gas for heating purposes would be that, the constituents of which should be all combustible, should be possessed of high thermal powers, and should produce, on burning, compounds of small specific heat. No gas which has yet been produced for use as fuel com- pletely fulfils these conditions. Common coal-gas contains such non-combustible bodies as carbondioxide and nitrogen, and among the pro- ducts of its combustion is water, a body of large specific heat, and also requiring a considerable amount of heat to convert it into vapour. The complete combustion of coal gas also necessitates a comparatively large supply of air, and this, again, involves special mechanical appliances. Nevertheless, coal-gas has been proved to be, for cer- tain purposes, a cheaper, more effective, and more easily managed fuel than coal, wood, or other forms of solid heat-giving material. That steam is decomposed by hot carbon with the production of a gaseous mixture of considerable heating powers, has long been known, and several attempts have been made to utilise the products of this decomposition. These attempts have met with no great success on account of the cost of the plant required to work the manufacture and of the difficulties of the process. Long-continued experiments have, however, been carried on, and it would appear from a paper recently communicated to the Society of Arts by Mr. S. W. Davies, that these experiments have been crowned with a very fair measure of success. The great difficulty was a mechanical one : it has been very simply overcome. Superheated steam is pro- duced in a coil placed within a cylinder and is driven by its own tension in the form of a jet into the lower part of an anthracite fire. The jet of steam carries with it air sufficient to actively maintain the combustion of the anthracite ; the gases issue at the top of the apparatus and pass into the mains. The fire is fed from the top by an arrangement which allows of the process being con- tinuous. Water is forced into the coil under a pressure varying from 15 lbs. to 40 lbs. on the square inch. The whole apparatus is compact and simple. The products of the decomposition of steam by hot carbon are mainly hydrogen and carbon monoxide; traces of marsh gas are also formed. Could these gases be produced free from admixed non-combustible bodies we should have a gas of very high heating powers. But the temperature of the glowing carbon must be main- tained by the introduction of oxygen, that is, in practice, by the introduction of air. The problem how to intro- duce air sufficient to keep up vigorous combustion, and at the same time to maintain the decomposition of the steam, appears to have been satisfactorily solved ; but the introduction of air means a lowering of the heating power of the gas produced, inasmuch as four volumes of nitrogen are brought in along with every volume of oxygen supplied. By passing the gas through a series o vessels containing hot carbon the nitrogen may be very much diminished in amount, and the heating power of the gas proportionally increased. The gas produced by the decomposition of steam by hot carbon always contains traces of carbon dioxide which is non-combustible ; the amount of this compound may, however, be reduced to 3 or 4 per cent, by regulating the depth of the layer of hot carbon through which the gases pass, and by maintaining the temperature of that carbon at a high point. But the maintenance of a high temperature throughout a mass of carbon can be accom- plished, under the conditions of the manufacture, only by introducing a rapid current of air, which again means a dilution of the gas produced. If, therefore, means could be found forefeeding the anthracite fire with oxygen, a gas of very high heating power might be produced. A supply of oxygen at a cheap rate is a great desideratum; the gas exists in practically unlimited quantity in the atmosphere, but an easy and successful method for separating it from the nitrogen with which it is there mixed is still only hoped for by the chemical manufacturer. Were a supply of oxygen forthcoming, mechanical difficulties would present themselves before it could be utilised in the production of "water gas." The introduction of too small an amount of oxygen would mean the non-decomposition of the whole of the steam and the cessation of the combus- tion of the anthracite; the introduction of too much oxygen would mean the production of carbon dioxide in considerable quantity. But by regulating the size of the steam jet and of the blast-pipe, these difficulties might probably be overcome. As the gas is now produced all danger of explosion is removed. The heating effect of the gas as at present manufactured is about one-fifth that of ordinary coal-gas, for equal volumes ; but the cost of the gas is so much less than that of coal-gas, that a given amount of heating work may be done — according to the figures given in the paper referred to — by using the new gas, with a saving of from one-third to 'two-thirds of the expenditure which would be involved were coal-gas employed. Although the new gas is not perfectly adapted for the purposes for which it is to be used, yet there can be little doubt that we are now a step, and a very consider- able step, nearer the final solution of the problem. Doubtless improved furnaces, and improved apparatus generally for burning the improved fuel, will be introduced. Majf 9, 1878] NATURE 35 The production of a cheap gaseous form of fuel is a great gain ; so also is the invention of a means whereby the large stores of anthracite coal in this and other countries can be utilised. Of all the forms of carbon experimented with in the production of the new gas, anthracite was found the best. Anthracite is difficult to burn ; the ordinary forms of furnace do not admit of such a complete oxidation as •is required in order to maintain the combustion of anthracite. But the blast of air carried into the gas generator of the water-gas apparatus by the steam jet insures the presence of a large quantity of oxygen, and therefore the combustion of the anthracite. Whether a simpler means could not be adopted for the combustion of anthracite is a question worthy of consideration. That a steam jet can be thrown into an ordinary furnace charged with anthracite, and the combustion of the coal be thereby insured, has been shown to be possible. Nevertheless, the production of combustible gas from the anthracite is to be preferred, for many reasons, to the consumption of the solid fuel. The fact that we shall soon probably be in a position to make use of our stores of anthracite, is one of very -considerable importance from an economic point of view- In possessing large quantities of anthracite we possess a a valuable commodity, but if we cannot realise a use for that commodity it ceases to be a source of wealth to us. Further, large quantities of anthracite are known to ■exist in some of the British Colonies and in the United States ; the utilisation of these would mean an increase in the commercial enterprises owned by Englishmen abroad, or supported by English capital ; it would also probably imply an increase in the tonnage of shipping, and would thus tend to increase our " international wealth." Whether it be regarded from the point of view of the chemist, or of the economist, the introduction of a cheap gaseous fuel manufactured from anthracite, marks a ■point of no little importance in the advance of manu- facturing industries. The experiments detailed in the paper by Mr. Davies •show that the new gas is especially adapted for use in cooking 'operations in large private establishments, in clubs, hotels, barracks, &c. It is known that cooking can be more cheaply and more rationally conducted with the aid of gaseous than of solid fuel ; if the new fuel does all that it promises to do, judging from the actual trials already made, its introduction will be welcomed by the artistic cook no less than by the scientific chemist, and by the political economist. M. M. Pattison Muir FOSSIL FLORA OF GREAT BRITAI N The Fossil Flora of Great Britain; or. Figures and Descriptions of the Vegetable Remains Found in this Country. Illustrations of Fossil Plants, being an Autotype Repro- duction of Selected Drawings prepared under the Super- vision 0f the late Dr. Lindley and the late Mr. William Hutton, between the Years 1835 and 1S40— and now for the first time published by the North of England Itistitute of Mining and Mechanical Engineers. Edited by G. A. Lebour, F.G.S. (Newcastle-upon-Tyne, 1877.) THE publication, in 1831, of the first number of the "Fossil Flora of Great Britain," by Dr. Lindley and William Hutton, marked the beginning of a new era in the history of English Palseo-phytology. Much had been previously done on the Continent. The magnificent Flora der Vbrwelt of Sternberg had laid a solid foundation for such studies, and the Vigltaux Fossiles of Adolphe Brongniart, then] in progress of publication, was not only widening those foundations, but was systematising the study, as his "Prodrome'* had developed the first principles of the philosophy of the primaeval Flora. The ^late Professor Phillips had further recorded additional discoveries amongst the Oolitic plants of Yorkshire, in his " Geology of the Yorkshire Coast"; but there yet remained a wide field for explora- tion, especially amongst the plants of the Carboniferous age, in which England was especially rich; and Phillips and Brongniart were very far from having exhausted the newly-discovered plants of the Yorkshire Oolites. Hence when the two able authors above named commenced the publication of their "Fossil Flora," they found a vast mass of new materials awaiting their investigation. In endeavouring to estimate the true value of their work, we must not regard it from our present standpoint, but from that of the time at which they began their labours. At that period, . though collections of fossil plants were numerous, they were scattered over the country in isolated cabinets, and no one knew much about what those cabinets contained. Hence the first work demanding attention was to ascertain what the forms and general relations of these fossil plants were, and the pages of the " Fossil Hora" gradually gave the needful information so far as it was then obtainable. The two authors named figured and described such distinct fragments as fell into their hands, and thus made available for the students of a later period a vast mass of hitherto unknown material- This important" publication went on for several years — but at length the two authors became weary of their costly venture. The number of persons actively interested in the study of fossil plants was not sufficiently great to cover the expense of the publication, which consequently came to an abrupt end. In 1839 the late Dr. Lindley told the writer of these lines that he saw no reason why he should employ his purse for the benefit of the geolo- gists who failed to give him the needful support, and he acted upon the conviction thus expressed. In endeavouring to measure the true value of the work of Lindley and Hutton to modern science, we must not forget the date of their labours. At the earlier part of the time when the publication of the "Fossil Flora" was in progress, little or nothing was known of the internal organisation of any fossil plants. But at length two instructive fragments were obtained in England — one of a Lepidodendron, and the other of a Stigmaria — both of which examples revealed a measure of minute internal organisation. Witham's " Observa- tions on Fossil Vegetables," published in 1 831, contained figures and descriptions of the first of these specimens, the now well-known Lepidodendron Harcourtii, and the Stigmaria was figured and described in the " Fossil Flora." These two specimens were the beginnings of a rich har- vest, which is even yet but very partially reaped, but which has already prepared the way for a revolution in the processes and results of Palaeo-phytological studies. But though the authors of the "Fossil Flora" thus obtained some glimpses into the possible future of their science, 36 NATURE {May 9, 1878 they did little more. Like good and true men they did the best they could with the materials within their reach. They found various dissimilar fragments of apparently distinct forms of fossil plants which they named, figured, and described. They thus introduced a certain degree of order and definiteness into what had hitherto been a rudis indigestaque moles. This work benefited not only contemporaiy but succeeding races of geologists. Such labours as these are the necessary preliminaries to the more exact determinations of more advanced science- Work like this has to be done in the early stages of every branch of natural science, and no great harm arises from the multiplication of genera and species, if we only keep in mind the fact that such nomenclature is but provisional; — a mere ticketing of special forms for convenience of future reference. The names do not indicate very much more than the fancy designations given to various "makes" of cloth in a Manchester warehouse — i.e. convenient terms by which the business transactions of buyer and seller are facilitated. Mischief only arises from this essential method when we make these provisional nomenclatures the basis of ambitious philosophical speculations ; when, for example, because a plant is designated by the name of Palmacites, we con- clude that Palms flourished in the carboniferous age. Keeping in mind the true use of a provisional nomen- clature we find it indispensable to further progress. When some inquirer, more advanced than his predecessors, demonstrates that Sigillaria A and Sigillaria B are merely the upper and lower parts of a common stem, it is useful to him to be able to indicate by his terms A and B what the types are that bear this mutual relationship. The scientific worthlessness of very many of the generic and specific definitions and names of fossil plants is now becoming obvious to all advanced students of Fossil Botany. Yet the assignment of these names and definitions to such fragments as fell in their way is the chief result of the publication of the "Fossil Flora." To the philosophy of the study its authors added very ittle. They left the supposed relations of the great types of vegetation t© each other pretty much where they found them. They seem to have accepted equally what was true and what was false in the philosophy of Adolphe Brongniart. No one important discovery will be handed down to the future associated with their names. Frag- ments from various parts of the same plant took rank at their hands as independent species. Little or>o attempt was made for variations due to age and conditions of growth. Nor were they to be blamed for this. We are still to some extent in the same predicament — only, thanks to the warnings of Sir Joseph Hooker and others, we now know what we have to aim at. We have to try to accomplish for plants what Burmeister did for the Trilobites. But if the use of merely provisional names is to be continued, it is very desirable that we should possess some means of distinguishing between such a nomenclature, and one that represents philosophic truths and may be employed as the basis and instrument of philosophical speculations. Nothing of the kind has yet been attempted beyond the "incerta sedes " of Brong- niart. Yet I think it would not be difificult to invent some technical sign that would answer this end. For the present it can only be left to the judgment of each indi- | vidual observer to determine what names are of scientific value and what are not. But the most essential truth which these later days are teaching us is the importance of the study of internal organisation ; and especially of that of the reproductive structures, if fossil botany is to take its proper rank as a definite science. Nothing can be more dangerous than a reliance upon mere resemblances or differences of ex- ternal form. We have a ready illustration of this in the numerous verticillate-leaved plants of the Carboniferous beds. So far as mere external forms are concerned, Calamites, Asterophyllites, Sphenophylla, and Annularize, with a host of less known modifications, bear a close resemblance to each other — and if a few Galium s, As- perulas, and other similar living exogenous forms could have been thrown in amongst them they would probably have been equally undistinguishable from the rest. The result is that the nomenclature and classification of these Carboniferous plants is in hopeless confusion. True, we are slowly emerging from this chaos, because we are learning to distinguish some of these forms from the rest through their widely differing features of internal organisation — and every fresh plant in which we do so diminishes the bulk of the chaotic mass that still needs reduction to order. Though so much has already been done in this way, we are yet only on the threshold of the study. At the same time we are moving in the right direction. Such localities as Autun, St. Etienne, Oldham, and Halifax have furnished, and are likely further to furnish, important materials — each locality having revealed characteristic forms of vegetation peculiar to it, mixed with other forms common to all the localities. It is to be hoped that other similar storehouses will be opened out, revealing fresh forms of structural organisation, since it is upon organisation alone that a sound classifi- cation of fossil plants can be based. The recent republication of the "Fossil Flora" is almost an exact fac-simile of the original work — even to its title-page. Copies of the old edition being rarely obtainable this re-issue will be valuable to a large number of young geologists. At the same time it is desirable that something should be done to distinguish between statements still to be relied upon, and such as represent now exploded errors. This might have been done by the introduction of editorial notes — ^but instead of this, its accomplished editor, Mr. William Carruthers, is about to issue a supplementary volume, giving the existing state of our knowledge of many of the objects represented in the original work. This may well be expected to constitute a valuable addition to the volumes already issued. The second publication named at the head of this notice has an affiliated relationship to the " Fossil Flora." When Hutton died he left behind him numerous drawings of fossil plants, obviously prepared for publication, many of them having connected with them manuscript annota- tions of various kinds. A selection from these has been published in an elegant volume issued under the auspices of the North of England Institute of Mining and Mechanical Engineers. It is obvious that many of these drawings represent plants of more doubtful nature than the majority of those published in the " Fossil Flora.'* It might be expected that the more definite types would be first selected for publication. But this is precisely May 9, 1878] NATURE Z7 what appears to me to constitute the value of the volume in question. We have but too frequently, though very naturally, figured and described the more definable types, the more obscure and intermediate forms being left for a further consideration, which sometimes never comes ! Yet these obscure examples often teach most important truths. Had all writers paid due attention to such inter- mediate varieties, the science of Palaeo-Phytology would have been less afflicted with premature ''classifications " than has been the case. Hence the spirited society that has pubHshed these posthumous Huttonian memorials is entitled to the thanks of all Palceontologists. W. C. Williamson TAXIDERMY Practical Taxidermy; a Mamcal of Instruction to the Amateur in Collectings Preserving, and Setting up Natural History Specimens of all Kinds. By Montagu Browne. (London: Bazaar Office, 32, Wellington Street, Strand. No date.) ACCORDING to the dictum uttered, or supposed to have been uttered, by one of our leading ornitho- logists, " The worst use you can make of a bird is to stuff it," and in nineteen cases out of twenty this saying is true, for, from a real naturalist' s point of view, com- paratively little can be got from the stuffed and mounted specimen not only of a bird but of almost any other animal. Nevertheless, there is a very large class of persons who are not real naturalists, and to them the skin of a beast, bird, reptile, or fish, duly prepared and embellished with glass eyes, stuck up with wire through its leo-s in a glazed box, and surrounded by imitation foliage, dried and dyed herbage, is a joy for ever, though perhaps not even to them a thing of beauty. For this large class the present book is intended, and it will probably attain its object, notwithstanding that how far the animal stuffer's trade is to be learned from any book without actual de- monstration seems to be questionable. The author's practical knowledge of his business is, we doubt not, con- siderable, and it would have been better had he let alone some of the matters not really relating to it upon which he descants. His very first sentence tells us that taxidermy " is derived from two Greek words, a literal translation of which would signify the 'skin art'" — a statement which beats the time-honoured explanation of Hippopotamus, from hippos, a river, and potamos, a horse, inasmuch as taris has as little to do with art as with the Queen's taxes — and then goes on to inform us, from Herodotus, the Pemiy Cyclopcedia, and other trust- worthy authorities, how the Egyptians made mummies, which is all as delightful as so ghastly a subject can be, but is certainly somewhat superfluous as " Instruction to the Amateur" in "preserving and setting up Natural History Specimens." Hardly less unnecessary is Chapter II. devoted to "Trapping and Decoying Birds and Animals," whereby we may remark that the author is of that persuasion which denies the animal nature of birds. But we may pardon him this and other offences for what he says (pp. 14, 15) against the needless destruction of the rarer "birds and animals," and thence to Chapter X. is much more to the purpose. We are sorry to see, however, that he is addicted to the usual taxidermist's mannerisms, most of which are fatal to good and artistic mounting. Paint, for instance, however thin, on bills and legs is an abomination. If colour is required it ought to be supplied by subcutaneous injec- tion, which in the majority of cases can be easily and successfully done. Artificial twigs of wire and tow, dusted over with powdered lichens and the like, are nearly as objectionable as the external application of paint. As regards the stuffing of heads of large mammals the instructions given ara really good, but we suspect that a satisfactory result cannot be obtained without far more experience and closer study of nature than the author Avould have us think necessary. We must re- proach him, moreover, for not giving a hint to the learner as to the best mode of preparing the "skin" of a bird so as to prevent its head from breaking off. This is done by inserting a long lock of cotton-wool of tow into the cranium (from behind, of course) making it fast there by tight packing, and then twisting the remainder of the lock into a kind of loose cord, which does not distend the skin of the neck, enables its length to be adjusted as may be required, and finally affords a cohe- rent and effectual support, whereas the ordinary mode of ramming bit after bit of stuffing into the neck has exactly the opposite tendency. Mr. Montagu Browne speaks with complacency of the achievements of English "artists" in taxidermy; but it seems as if his acquaintance with foreign works was limited to the comical creatures from Wiirtemberg in the old Exhibition of 1851. We venture to say that there is hardly a museum on the Continent which has not its specimens mounted in a style that no professional in these islands can equal — certainly not surpass. When we look at that really awful group of the boa and the peccary, recently erected in the British Museum, we blush for the handiwork and ignorance it displays. The impression it gives is that the boa, being crammed into a cylindrical form, is quite inflexible, and that the peccary, though not a learned pig, is fully aware of the fact, so, feeling sure that there is no chance of his being crushed by his enemy, he rather likes the adventure than not. The question of the use of arsenic in preparing skins we cannot discuss at any length. Our author declares that Tinece and Dermestce laugh it to scorn, even if they do not, as he believes, like the Styrians, "fatten on it" (p. 44). We shall only say that we prefer it, and know of a case in which a collector in the tropics, having exhausted his stock of the poison, was compelled to prepare some of his specimens without it, which speci- mens were some years afterwards attacked and greatly injured by insects ; while others, obtained before his store gave out, and duly arsenicated, remained unharmed, though lying side by side in the cabinet with the speci- mens that suffered. Arsenical soap, it is true, does not keep either feathers or fur safe, simply because it cannot be applied to them, but it certainly preserves the skin according to our experience, and every travelling collector should unquestionably use it. Corrosive sublimate is effectual for a time, but the best preventive is a well- fitting cabinet — care being taken that infected specimens are never introduced to it. In conclusion let us caution our readers not to be misled by the similarity of the 38 NATURE {May 9, 1878 author's name into confounding the present book with one on 'the same subject published many years ago by Capt. Thomas Brown. OUR BOOK SHELF The Gold-Mines of Midian and the Ruined Midianite Cities. A Fortnights Tour in North-Western Arabia. By Richard F. Burton. (London : Kegan Paul and Co., 1878.) Captain Burton has managed to make a wonderfully interesting and really valuable book out of his fortnight's visit to the ancient land of Midian, on the north-east side of the Red Sea, on and to the south of the Gulf of Akabah. Long ago he had good reason to believe that in this region gold was to be found, but only in March and April of last year was he able to test his surmise, under the auspices and at the expense of the Khedive. The result of this visit is that he is satisfied that there exists a real Ophir, a regular California, extensively worked in ancient times, and whose valuable product is probably not unkno\vn to the tribes who haunt it at the present day. Not only gold exists there, but vast deposits of iron, with copper, tin, and other metals — in fact a wel- come treasure-house for the impecunious Khedive. Capt. Burton has hopes that modern Midian, now almost a desert, may yet rival the ancient land from whose people the Israelites, in the exercise of their divine vocation, carried off " the gold and the silver, the brass, the iron, the tin, the lead." Capt. Burton made a minute inspection of some of the ancient sites, and has a good deal to say on the archaeology of the region, as well as its zoology, botany, and geology. But the book is not nearly all on the land of Midian. From the time that the author left Trieste for Alexandria and Cairo, by Suez to Midian, till his return, he saw many things on which, in his own digressive and parenthetical style, he [.has much to say that is worth listening to. Capt. Burton has just returned from another visit to Midian, and no doubt we shall soon have another work or an enlarged edition of the present. To the Arctic Regions and Back in Six Weeks, being a Summer Tour to Lapland and Norway, with Notes on Sport and Natural History. By Capt. A. W. M. Clark Kennedy. Map and numerous Illustrations. (London : Sampson Low and Co., 1878). The title of Capt. Kennedy' s pleasant volume is rather misleading ;' before looking into it we thought he would take us as far as Spitzbergen at least, and felt somewhat **sold" when we found his journey ended at TromsOj in the north of Norway, which, though within the Arctic Circle, is not usually spoken of as in the Arctic Regions. Still Capt. Kennedy's book is thoroughly readable, and though it will add little to our knowledge of Norway or of the Lapps, will prove valuable to any one contemplating a visit to that now much-frequented tourist ground. LETTERS TO THE EDITOR [The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts. No notice is taken of anonymous communications. [The Editor urgently requests correspondents to keep thdr letters at short as possible. The pressure on his space is so great that it is impossible etherwise to ensure the appearance even of com' munications containing interesting and novel facts.l Eastward Progress of Terrestrial Magnetism As the progress of weather eastwards is one of the subjects -now engaging attention, while the possible connection between meteorological and magnetical phenomena is another, we are led to ask if there be no traces of an eastward progress in cer- tain of the phenomena of terrestrial magnetism. I cannot yet affirm that such is the case, but it may interest your readers to know that, as far as a preliminary investigation goes, there are some indications of such a progress when we compare together the Declination-ranges at Kew and at Trevan- drum. It will, however, require a more thorough discussion before the fact can be considered as at all established. Manchester, May 4 B. Stewart The Phonograph Since writing my former letter on the phonograph {NATURE, vol. xvii. p. 485) I have had the advantage of seeing some of the work that Prof. Fleeming Jenkin is doing with his own instrument, which must, I think, be more sensitive than the one I examined. This work convinces me that the phonograph has already risen beyond the rank of lecture illustrations and philo- sophical toys, to which I assigned it in my last, and that it promises to lay some permanent foundations for the more accu- rate investigation of the nature of speech sounds. Prof. Fleeming Jenkin, by a most ingenious arrangement, which I must leave him to describe inhis paper to the Royal Society of Edinburgh, obtains vertical sections of the impressions made on the tin-foil by the point of the phonograph, magnified 400 diameters. Some of these original tracings I had the pleasure of seeing yesterday, and they are full of interest. I have termed them "speech ciuves." They differ considerably from the phonautographic speech-ciu^es of Leon Scott and Koenig, which only succeeded with the vowels, and from the logographic speech-curves of Mr. Barlow, which only succeeded with the consonants, in so much as they succeed with both. In such a word as tah, for example, intoned rather than sung, but not simply spoken, as the vowel would otherwise not last long enough for subsequent study, we have first the " preparation," in which the curve gradually, but irregularly, rises, then the "attack," where there is generally a bold serrated precipice, with nxunerous rather sudden valleys ; next the " glide " where there is a perfect tumult of curvatures arising from the passage of voice through a continually changing resonance chamber, producing a rapidly and continuously chang- ing but indistinct series of vowel sounds, which gradually settle down into the "vowel " proper. In the vowel, if well intoned^ the curve remains constant for a considerable number of periods, beautifully reproducing itself, but, as the intoner becomes exhausted, "vanishing" away gradually to silence, the distinc- tive peculiarities of the curve disappearing one by one, till a dead level is again reached. Then Prof. Fleeming Jenkin subjects this vowel curve to "analysis," reducing it to the separate "pendular" curves of which it can be composed. This corresponds to determining the "partial" tones {parzialtone, theilt'dne of Helmholtz, of which all but the lowest are called oberparzialtbne, obertheiltone, and by contraction obertone, whence the unfortunate English word over- tones, which is constantly confused •w\\h. partials, thus assuming a part for the whole) out of which the whole " compound" tone is formed. The first two partials are much stronger than the rest,, the second often stronger than the first (hence the frequent con- fusion of octave ?), the others generally very weak, although ex- ceptionally one of the higher partials may be stronger. As many as five partials, as far as I remember, were traced out in the analysis Prof. Jenkin showed me, which he had just received from Edinbiu-gh. The results differ materially for different speakers. Also there is a pecuharity in the "phase" with which the different partials enter into combination. Helmholtz: showed that this difference of phase would materially alter the form of the curve, but would not alter the appreciation of quality by the ear depending upon the actual partials and their degrees of loudness alone. The phonograph, as I have said, resembles rather a worni " print " than a " proof " of the human voice. This means, of course, that the delicate upper partials, on whichj all brilliancy depends, are absent. In some respects this is advantageous for the very elaborate inquiry which Prof. Fleeming Jenkin has- instituted, for it enables him to catch the bold outlines on. which genera depend, without being at first bewildered by the. delicate details which give specific differences. Our speech sounds are, of coiuse, individual, and what is recognised as the- same speech sound varies in the same speaker within the limits of its genus, almost every time it is used. We shall do muck if we establish the genus. The extent of Prof. Jenkin's researches, as he contemplates them, and the care with which May 9, 1878] NATURE his initial experiments, tracings, and analyses have been con- ducted, lead us to hope that we have at least got an instrument which will enable us to solve the elementary problems of phonetics that have hitherto almost baffled u?, although it is not suited, as yet, to fix those delicacies of utterance which were my own special object of investigation. April 30 Alexander J. Ellis On repeating the experiments with the phonograph narra'ed by Mr, A. J. Ellis in Nature, vol. xvii. p. 485, upon a different instrument, I have found the results of my ex- perience to differ in several respects from his. Doubtless each instrument possesses its own individual characteristics ; hence it will be the more needful to exercise caution with respect to generalisation, especially as the existing instru- ments are few and in the hands of few observers. Mr. Ellis has been careful to state the nature of the instrument with which his results were obtained, and the name of Mr. Stroh is a guarantee for the construction of the mechanism. The instrument with which I have been working is of homelier make, and not provided with a driving-train or governor, but simply turned by hand. The same disc — a three-inch ferrotype plate — serves as receiver and transmitter of the voice. The foil used has been, if anything, a little too thin for the purpose. On trying the sounds aabaa, aadaa, &c., I found the con- sonants clearly distinguishable, except the sibilants. Aajaa, which is stated by Mr. Ellis to be faultily delivered by the instru- ment, was perfectly recognisable, and could be distinguished from aadaa. Neither was there any confusion between jack and dock or tack; hut Jacques, with the soft /, was sounded out by the in strument as /laak. My phonograph makes the clearest possible difference between the words ioui and ^zV^when carefully spoken, the diphthongal sounds coming cut beautifully as bdaoot and baaeet. On reversing the motion of the handle, tfeadb and tooaab were unmistakable. The double nature of some of our conso- nantal letters is very clearly demonstrated by this process of reversal of motion, as Messrs. Fleeming Jenkin and Ewing have already shown. To the sounds they name let me add that of ch in the word cheque, which we ordinarily pronounce tshek. This word gives a very peculiar sound when reversed in the machine. The greatest difficulty— that of getting an instrument to acknowledge the sibilants — is a difficulty that all who have worked with phonograph, phonautograph, or telephone, admit. . The remedy mentioned by Prof. Mayer, that of using a mouthpiece with a very small hole, has the incon- venience of diminishing materially the loudness of the articu- lation of the machine. I have found it better to fasten a strip of card or watchspring across the opening, edgeways, so that the voice impinges on the edge of the strip. With this device sibilants are improved ; the word scissors becomes practicable, though ''Scots" is still intractable. One of Mr. Stroh's instru- ments, which was shown at; the Crystal Palace during Easter week, gave s and 2 fairly. In a familiar phrase the jes are not much missed : Steady, boys, steady, is given with less marked defect of speech than if uttered as thteady, boyih, thteady. Another point of interest that has not, 1 think, been yet mentioned by observers is, that the marks corresponding to the vowel sounds differ when the mouth is at different distances from the vibrating plate, but that yet there is no difference in the vowel subsequently emitted by the machine ; a result which confirms the previously known independence of the vowel sound of the phase of its component partials. For some time I thought my phonograph guilty of dropping its Ks (though not made within the sound of Bow bells), but when that letter is spoken rapidly in a word it is recorded faithfully. Happy land is well heard in the instrument ; and How do you do ? is also aspirated. Cturiously enough, this sentence is spoken almost as well back- wards as forwards (except the aspirate), especially if spoken to the machine with a strong Scottish accent. It is remarkable how useless an instrument without a clockwork regulator is for reproducing even the simplest airs : they are simply lost in noise. Altogether the study of speech by the phonograph is most interesting, and will furnish some most valuable data to students of language and of acoustics. It is impossible to wit- ness its performance without a tribute of acknowledgment to the extreme ingenuity and skill of its inventor, Mr, Edison. SiLVANus P. Thompson University College, Bristol, May i On the Use of the Virial in Thermodynamics The ingenious experiment and the deductions from it, de- scribed by Mr. S. Tolver Preston in Nature, vol. xvii. p. 31, throw a flood of light on the subject of availability of heat-energy, which altogether alters the basis upon which the hitherto imper- fectly expressed conditions of the use of this form of energy will be made to rest Mr, Tolver Preston has, in fact, discovered that discriminating "sprite," or being whom Prof. Clerk-Maxwell imagined ("Theory of Heat," 1875, p. 328) singling out the fast-moving, and separating them in a space by themselves (with- out any expenditure of energy), from the slow-moving molecules of a gaseous mass ; or what is nearly equivalent to this, he has at least shown how some fast-moving and some slow-moving particles of a mass of gas originally in equilibrium, both as to temperature and pressure, zvi/l naturally be so guided amongst each other, that their joint energy will become more available than it was before. But it has, perhaps, not occurred to Mr. Tolver Preston and to some of your readers, that this power or faculty of rendering heat- energy available, which mutual diffusion of heterogeneous gas masses, either through a porous septum or in their own contiguous layers possesses, is a consequence of the general form of efficacy belonging to force, of which Prof. Clausius pointed out the existence in his important propositions on the " virial," ^ as he has ttrmed one of the two members, of which this kind of mechanical tendency of force is the sum. The other member of a force's " radiahty " (as it may be termed) "with respect to a given point," is the vis viva * of the material particle upon •which it acts, in a space of which the selected point is the origin. In description of this newly-discovered natural tendency of a force with respect to a given point or focus,, it is enough to say that while the statical moment of a force, or the product of the distance of its point of application from a point or fulcrum by the resolved part of the force perpendicular to this distance tends to increase uniformly the moment of momentum (defined similarly with that oi force) of the particle upon which it acts, so does the "radiancy" of a force, or the product of the distance of its point of application from a given point or "fccus,'^ together with the vis viva of the particle upon which it acts, tend to increase the "radiancy of momentum" of the particle de- scribed in the same way as the radiancy (or the first term of the radiality) of the force, as just defined. We may speak of the radiancies of equal and opposite reactions, or of force-pairs, in the same way that we deal in statics with the moments of couples ; with similar general properties of their equilibrium, including the resoluticn of the total radiancy (like the impulse, the horse-power, and the moment) of a system of forces, into an internal and an external part wi h respect to the centre of mass of a material system upon which it acts ; and there are principles of conservation of moment and of radiancy of momentum about any point, taken as centre, of all the force-pairs whose moments and radiancies balance each other on a material system. Only the system's vis viva re'"erred to the centre is in the latter case the rate of charge of its radiancy of momentum relatively to it. It is in the same way that the conservation of the motion of the centre of mass, and the conservation of energy, are principles of nullity or of inaction of two other forms of force- agency balancing each other on a material system (the impulse of foices, and the product of their impulse by the virtual velocity of their point of application, or their "horse-power") to which we are obliged to have special recourse to resolve the particular varieties of questions of the " transfer of energy " which occur in mecha- nics. But it is remarkable that the radiality of a force-pair includes the vis viv* of its mass-couplet as one member of its mechanical efficacy, and a surprising example of an agent (evidently the agent cf heat-distribution) here presents itself in which vis viva itself is one of the active elements of the mechanical variation or compulsion ! Its total tendency in any body acted on internally only by directly reacting force-pairs is the total vis viva, and the sum of the virials of these force-pairs, diminished, if the body is subjected externally to a uniform pressure normal to its surface, by three times the we'l known product of this latler pressure by the volume of the bcdy (written -^pv). I Poggendorff's Annalen, vol. cxli. (1870), p. 124. But Ciausius, it should te remarked, gives the name " virial " to half oi the quantity which I h»ye described below as the " radiancy " of a force. An exposition of Clausius' new mechanical expression, the virial, with an explanation by its means of the process of condensation of vapours into the liquid state, was given by Prot. Clerk Maxwell in his lecture to the Chemical Society on the molecular theory cf the constitution o'' gaseous and other bodies, in 1875. (See Natubb, vol. xi. p 357 ) ^ Using this word for ^«7i,v the qrartiiy usv.&lly dcscriled as a particle's "kinetic energy." 40 NATURE [May 9, 1878 In the mutual inter-diffusion without change of temperature of two gases of different densities through a fixed porous diaphragm, although no energy is withdrawn from or communicated to either of the gases, the rate at which single molecules take their equal measures of gas volume through the partition being very different, like their velocities, the measure of gas-volume which accumulates on the side of the denser gas soon raises the pressure there, in- creasing the intensity of the mechanical tendency 3/ z^ on that side of the partition, while the same kind of mechanical tension diminishes on the other, and the t«mperature on each side of the partition is at the same time unaffected . As the porous diaphragm by its immobility (which prevents one of the sets of molecules from doing any work upon the other) resists the resulting force upon it, its counter-tendency is entirely derived from the increase of its own external virial, which has sprung up (at no expense of work, supposing the_diaphragm to be perfectly rigid) in main- taining everywhere in spite of their impacts the common tem- perature or mean energy of bath sets of molecules. Were the diaphragm away, it is evident that the rapid flow of rare gas- volume across the confines between the two gases towards the denser side would cause the centre of mass of the gas-layer, in which the mixture begins, to move bodily away from the denser gas, just as the diaphragm would do if it were free to move ; and the bodily motion so given to the medial gas-layer will, as a form of external radiality in the layer, arising from the heterogeneity, require, in order to be constantly neutralised in the whole body of the mixing gases, such a redistribution of their temperature and density to be taking place at every instant throughout the two bodies of gas placed in communication, that their centre of mass as a connected (but otherwise isolated) system may never undergo any change of place during the mutual diffusion. The space originally occupied by the rarer gas will accordingly become the hotter, and that by the denser the colder portion of the whole volume which the gases continue to occupy when they are mixed. It is in the same way that we can explain the action of re- generators in such air-engines as Stirling's and Ericson's, in passing through which gases change their temperature and volume (and therefore their tendency or "radiality," ^ - 3 pv), at constant pressure, the counter-tendency being at the same time lodged or relaxed during the process in the regenerator, where it must be kept by non-conduction in the tense state (of actual heat- energy and virial combined) of "radiality "^corresponding to the similar "heat- tension" of the gas by which its heat- energy exchanges are secuied. The prpperty of the usual non-conductivity required in the regenerator, is one of indifference of the molecules of a substance to the radiality (or to the sum of the sensible heat and the virial), of neighbouring molecules, or in which different values of the quantity E -^pvoi small neighbouring parts of the sub- stance equalise themselves with difficulty through the mass. But perhaps it is not the inter- but only the jw/rc'-molecular forces that furnish the radiality (and "virial") that determines the trans- mission of heat? If the former forces balance each other, which they do when the body is not vibrating by its elasticity, the virial of the intro-molecular forces only, together with the vis viz0'^fi\z.y be "conservative" with regard to heat-energy, and may be employed in its transmission? Since radiancy of momentum is not heat-energy, we see that this natural effect of force radiality, or of virial and vis viva combined, can only be converted finally into actual heat-energy by some mechanism peculiar to the molecular structure of the solid and liquid bodies in which the heat-energy transmission takes place. Some kind of heat-engine apparently effects this process, for example, at the confines between the vapour and the liquid, when steam is condensed into water, but it is certainly a non-reversible one when the water- spray is colder than the steam which it condenses ; and in the conduction of heat by solid bodies the process is also a non- reversible one ; we only know the part which sensible heat, as temperature, or vis viva, acts in promoting heat conduction ; and the virial by which it is perhaps also carried on, and which with vis viva conserves radiancy of momentum, may also be a fellow- regulator of the operation of which we have no certain knowledge, and over which we certainly have no direct control. But that it should invariably tend to lower the availability of heat, by heat conduction among the comparatively fixed molecules of liquid and solid bodies, will not, perhaps, when the internal motions of molecules are better understood, be more difficult to demonstrate from some theory of Its action, than that it should sometimes serve to raise the availability of thermal energy by its action on heterogeneous gas masses. A. S._Herschel College of Science, Newcastle-on-Tyne P.S. — Maturer reflection, since the first impression of surprise which Mr. S. Tolver Preston's announcement of the new experiment to which it relates caused me to ex- press at some length, and perhaps unguardedly, in this letter has shown me that the properties of the virial, easily as they may conduct to some Important results, do not. In this case, supply a complete solution of the problem of the final state of two gas masses at the same pressure but of two dissimilar densi- ties on temperatures left to diffuse into each other in a confined space. The equal pressure on all parts of the Inclosure pre- determines the fixity of the centre of mass during the process, and consequently an unequal distribution of density, and there- fore of temperature finally, when the mixture is complete ; but the equation of the virial or the principle of conservation of the radiancy of momentum supplies no certain Information what must be the law of this final distribvition, one of Its terms, 3/z', or the virial of the Inclosing pressiure, being capable of under- going unknown variations during the progress of the diffusion ; and although the stationary condition of the mass at last implies that this term will not be permanently changed, yet both its value and that of the system's total moment of inertia round its centre of gravity (the acceleration of whose magnitude is the rate of change of the radiancy of momentum) may vary in the interval, with the result of leaving the latter moment of inertia permanently altered to an extent and in a way which cannot be defined. When In the simple case of a perfect gas the con- dition of the virial fails to afford positive information regarding, the law of conduction and transference, or of rest and repose of. heat in them under various disti-ibutlons of temperature, it can hardly be expected that the same principle will furnish useful^ and definite results regarding heat-transmission through solids, and other kinds of bodies of which the modes of molecular aggregation are almost totally unknown. A. S. H. Time and Longitude There is an old and instructive problem which I have lately propounded to several people, and have been struck by the great variety of answers given to it. Although we often lose sight of the fact, it is nevertheless true that any given day or year does not begin all over the world at the same moment, but, commencing first at some point in the east, it travels round westward with the sun, so that two different years are often coexistent at the same moment, and it is easily possible for two events to occm- a few hours apart, and yet that which happened first to occur in 1878, and the later* event In 1877. In the same way each day of the week starts somewhere to the eastward of us and dies somewhere in the west. Taking, then, any given day of the week as Monday, the problem is — When and where did last Monday first com- mence, where did it end, and how long did it exist ? Or, to put a similar question, Where did the year 1878 first commence, and at what Greenwich time ? I will simply state my belief that last Monday commenced iii New Zealand somewhere about noon on Sunday, but not at noon, its commencement at that time and place being In no way connected with its position as our antipodes, but being a mere accident of civilisation. If the whole northern hemisphere should become civilised and inhabited, the day would then almost certainly commence at Behring's Straits, and would last forty-eight hours. A person crossing Behring's Straits east or west would gain or lose a whole day just as he now does by sailing round the globe ; so that he might easily cross over arid spend a few hours of to-morrow with his friends and return in time for dinner, or might enjoy the New Year's Eve on two successive days. If the Pacific Ocean became Inhabited land, a merldiaii would have to be chosen as a starting point for the day, and a person stepping across this imaginary line would gain or lose a day. At the same moment that Sunday morning was com- mencing on the one side of this line, Monday morning would be commencing on the other, and there would be con- stantly two different days going on side by side with twenty-fouf hours' difference of time between them, though only a few yards apart. It would be possible for a person standing astride this line to have for an instant one foot in Monday morning, the other foot In Monday night, and his body in the previous Sunday. I purposely avoid giving any reasons, and do not assert that air my views are correct, but I throw out the problem as an amusinT one for aroTiment and discussion, as it abounds In May g, 1878] NATURE 41 apparent paradoxes instructive. May 7 At the same time it cannot fail to be Latimer Clark Cumulative Temperature Attention has been called in your valuable paper to the idea of registering cumulative temperatures by means of a pen- dulum, by M. von Sterneck, vol. xvii. p. 308, and this has called forth several letters. One gentleman has put forward my name as having devised means with some success. In an instrument exhibited at the Royal Society soirk, 1876, I could have left the matter resting at this point, but I am induced to write by the letter of your correspondent, "B,"in vol. xvii. p. 486, who says, " The chief merit in this matter will belong to the person who puts the idea into a working form which can be proved capable of giving acciurate results." As I think that I have fairly attained this end, or at least pointed out the way to it, with your permission I will describe the means which appears by the correspondence interesting to many of your readers. In my cumulative temperature clock the impor- tant element, fhe pendulu?n, is constructed as follows: — A steel cylindrical tube 32 inches long, if inch internal diameter, is hermetically closed at both ends. A rod is attached to one of the ends, which is placed uppermost, to connect this pen- dulum with the clockwork in the ordinary manner. An air- tight division is made across the tube or chamber at 5 inches from the upper end. A small tube leads from this divi- sion to the bottom of the chamber. A conical plug is in- serted in the upper chamber, to be hereafter described. A screw plug is placed under the small tube in the outer tube to enable the upper chamber to be filled with mercury. When the pendulum is so constructed, the lower screw plug is removed, and the upper chamber and leading tube filled with mercury by means of a small funnel. In this full state the mercury is boiled, and the whole inverted. It then becomes a steel barometer. To convert it into a thermometer, a small air-hole is made in the outer tube (this is not shown in the engraving), and this hole is closed up with a small air-tight cock filled with a porous mate- rial. When this is screwed on and turned off, it is isolated from atmospheric pressure, and the mercury rises into the upper chamber by any increase of temperature causing expansion of air in the tube, and sinks in the same manner by loss of tem- perature, so that the pendulum becomes simply an air thermo- meter. The pressure of the air by expansion within the tube in the rising of the mercury changes the centre of oscillation of the pendulum and accelerates the clock, and vice versd. The clock is specially constructed to count beats only in units, tens, &c., up to ten millions, and the number of beats per day, week, month, or year, becomes the unit of temperature for the period. The exact length of time of each pendular oscillation being governed by the temperature at the time, the method becomes equal to one accurate observation at every second of time. The difficulties of construction and refinement required upon this general description are of two kinds, mathematical and mechanical. The models that I exhibited at the Royal Society's soiree were imperfect, being of blown glass. The difference of oscillation per day for 1° Fahrenheit, was in these about 50, as taken at the Lambeth Observatory by the late Col. Strange. In the steel instruments described there would be about 100 oscillations additional per day for the rise of each degree centi- grade. The mechanical difficulties are simply constructive. To obtain perfectly vacuum proof chambers, and to follow correctly the outline of the plug to be immersed in the vacuum- chamber. Also the adjustment of the correct volume of mercury, and the density of the contained air, by means of the cock, and the application of heat or cold to the outer case. The mathe- matical requirements are corrections. Thus : if the chambers were simply cylindrical, the mercury that rose by the pressure would have a different oscillation value for every point of space through which it rose. This might be corrected to equal scale value by making one or both the mercury-chambers conical, but it is much more simply done by inserting a conical plug in the upper chamber. There would also be a correction for the ex- pansion of the mercury and the steel case, and from any iiTa- tionality in the expansion of the contained air. The whole of this correction being derived from heat might he. made by one correction in the immersed plug. Prof .■ Stokes, Sec. R.S., kindly offered to calculate the exact form of this plug for me from data I was to supply. But I was ill shortly after this, and unable to attend to the matter, so I let it drop, but have the clocks and pendulums ready to complete some time hence. I send a diagram engraving which shows the principle of the pendulum No. 2, for cumulative temperatures. No. i is for ^jpsa Ei^^ y taking cmnulative pressures upon the same system, if the science of meteorology should require such exact means of obtaining permanent records of pressure and temperature for long periods as for months or years. Wm. F. Stanley South Norwood, April 22 THE INTERIOR OF THE EARTH ^ SIR GEORGE AIRY remarked that the nature of the subject was dififerent from any upon which he ever lectured before, in regard to its inde- finiteness and to the difficulty he should have if he considered it to be his duty to lead them definitely up to some point. He could only give them some idea ,^f the theory to which he wished to lead them, and in doing so he would advert collaterally to a good many points which might be valuable. He proposed to divide his address into three parts. The first would relate to the measures of the earth ; the second to observations on temperatvire ; and the third to the manner in which they might suppose the earth to have been formed, especially with regard \.o the nebular hypothesis ; and after that he would add some remarks on the conclusions to which these lead. He described the process called triangulation, by which a large part of the contour of the globe is covered, and by which it is possible to lay do-wn a map on which the distance between any one point and any other point is ascertained to within a few inches ; how that this was valuable in ascertaining the dimensions and figure of the' earth with the aid of the zenith sector, an instrument for measuring the apparent distances of stars from the point overhead. He showed on a large globe the prin- cipal lines of measurement which had up to this time ' Abstract of Address at the Cumberland Association for the Advance- ment of Literature and Science, by Sir George B Airy, K.C.B., F.R.S., As'tror.omer-Royal. Revised by the author. 42 NATURE \_May 9, 1878 been made for this purpose. From these measure- ments, there was no doubt that the earth is very nearly a sphere of 8,000 miles in diameter, or 25,000 miles in circumference. When he spoke of the sur- face of the earth, it must be understood that he spoke of the sea-level. Above that level stand moun- tains, and below are the depths of the sea. But although these inequalities of surface are taken into consideration by those who go accurately into calcula- tions, they are comparatively very small. Suppose he were to make a sphere twenty-five feet in diameter, re- presenting the earth, how much did they think the moun- tains would rise above the level ? One-fifth of an inch. Well, of course that never could be seen ; and it was a thing that in all ordinary calculations might be neglected. So that they might say that the earth was a sphere, with an exception he would mention presently. Then there was another thing which was important to their present subject, and that was the density of the matter of which the earth is formed ; and this was a matter which had engaged the best experimenters in two or three ways. The first of the experiments of this kind is a very cele- brated one known as the Schihallien experiment, so called from its being an experiment on a mountain in the Scottish Highlands (Perthshire) particularly adapted to these measurements, which are most favour- ably carried on in the north and south direction. It was found that the mountain Schihallien disturbed the plumb- line, causing a deviation from 'the vertical of 11" or 12". Then if that mountain, whose dimensions we can measure, turns the plumb-line so far, what is the proportion of its attracting mass to the attracting mass of the earth ? And as we know. the size of the mountain and the size of the earth, we can compare the density of the mountain and that of the earth. This process was gone through with great care, and it was found that, taking the density of the mountain as we could trace it by its constituent rocks, the density of the earth would be about four and a half iimes that of water, or about twice the average density of the surface rocks. The earth had density everywhere, but was more dense towards the centre than the outside. The next experiment is known as the Cavendish experi- ment. Here was a very light rod of deal, six feet long, suspended by a fine copper or silver wire (which is the most delicate suspension we can have) forty inches long, within a wooden case to defend it from currents of air. At each end of the lever was hung a ball two inches in diameter, and by a simple contrivance a pair of leaden spheres, weighing together perhaps 3oolbs., were brought simultaneously into the neighbourhood of the balls (but outside the case), on opposite sides, so that they might attract the small balls ; and the experiment was varied until, by a series of calculations, the density of the earth was ascertained, and gave a greater result than before, naniely, that the average density of the earth was about 5| times that of water. Then the third experiment was one which he made himself in the Harton colliery, near South Shields. That was by seeing how much the force of gravity was altered by going to a great depth, the force of gravity being ascertained and compared at the top and bottom by the swinging of a pendulum. From that a calculation was made, and it gave the density of the earth as six times that of water. He believed the best calculation was that founded upon the Cavendish expe- riment, and was quite willing to take something like 5^ times the density of water as the average density of the earth, including every part of it. There were conse- quences which followed from that which were certainly very striking. As this density was rather more than double that of the surface rocks, it showed that towards the centre the earth was more condensed than at the outside. But there was one result of the calculation which rather startled hini when he made his own experiment on the subject. Since these rocks press upon each other more and more the further you go down, what is the pressure upon the square inch when you approach the centre of the earth ? Many gentlemen there would have heard of a pressure of 50 lbs. or 100 lbs. on the square inch, and per- haps the greatest pressure we know is that by which tough Aberdeen granite is crushed — 10,000 lbs. to the square inch. But it must be 30,000,000 lbs. to the square inch in the centre of the earth ; and it is an astounding thing to imagine what consequences may follow. We have no idea of any such degree of pressure, and cannot there- fore conceive what its consequences may be. Perhaps thereby gas may be squeezed into gold or platinum, and powder to solid, or solid to powder — we cannot tell what it does. That enormous pressure, and our total ignorance of it, is one of the difficulties and troubles of this case. He thought the general state of the earth would be under- stood from what he had said, and now he came to the rotation of the earth. The earth revolves, as everybody knows, in the course of a day ; and everybody knows also, from the housemaid who whirls her mop to the greatest philosopher, that rotation will swell out the middle of the earth. Calculations have been made upon that, and the result is that the diameter of the earth in the equatorial direction is greater by about i -300th part than the diameter in the polar direction. When they found that the mea-. surement of the dimensions of the earth agreed so well with that conclusion, it led them to the further conclusion that the earth is, or has been, in a fluid state. In corro- boration of this, he would mention a singular circum- stance which occurred in our Indian Survey. In pro- ceeding northward from Cape Comorin, the curvature of the earth agreed very well for many hundreds of miles with that found in other parts of the earth (with due reference to the elliptic form of the earth). On approach- ing the Himalaya Mountains, the plumb-line was sensibly attracted by the mountains. The late Archdeacon Pratt investigated, from the form of the mountains and the density of the rocks, the disturbance of the plumb-line, and found that it ought to be much greater than it really is. Sir George explained this by supposing that the whole of that country is floating upon a dense fluid, and that the thick mass of the lighter mountain-matter sinks deep in the fluid, and that the displacement of denser matter neutralises almost entirely the attraction of the lofty mountains. The form of the earth is not such as would be taken by a solid structure, but such as would be taken by a fluid mass with solids floating upon it. In the second part of his address. Sir George Airy referred to what is known about the temperatures. They knew something of the rate at which temperature travels through the earth. The experiments on this point had begun, as many good experiments have begun, with the French, who fixed thermometers with very long stalks to the depth of twenty-five feet in the ground. These experiments were followed up, after some time, with similar thermometers at the Observatory at Edinburgh, and about the same time at the Observatory at Green- wich, and there the deeper thermometers were read every day. The first and most conspicuous result of these ex- periments is the retardation of the seasons. At the depth of twenty-five feet, high midsummer heat occurs at December, which shows that it takes five months for the heat to travel down that depth. If you compute it further, it takes 100 years to travel a mile; so that if the crust of the earth is 100 miles thick, it will take 10,000 years for the transmission of heat through it. This showed that really, after all, we may have a great deal of heat below us, and that it will not come to us for a very long time. It will come at last, but it will come travelling up slowly, and in the meantime the radiation from the surface of the earth will carry it off very rapidly. So that it is quite possible that with a cool surface there may be a great deal of heat below. In every part of the earth there is evidence of intense heat in former times. Maj 9, 1878] NATURE 43 The extent of volcanic action is partly lost on the earth by the effects of air and water ; but when they looked at the old rocks, they found there had been volcanic action almost everywhere. In our limestone rocks, for instance, there are the basaltic veins, which in some parts go by the name of toadstone, which are certainly the result of volcanic heat enough to produce fluidity. Almost every- where they found that there were volcanic streams inter- mixing with all the rocks ; and even although the surface of the earth had been free from volcanoes in a given district for a time, yet there had always been volca- nic action very near, enough to force in veins of Java from time to time. It seems, therefore, that we are entitled to say that we have always been near a gxQdiX. deal of heat — probably we have been much nearer it than at the present time, but still we are near enough to experience a great deal even in these countries. Repeated experiments have been made on the increase of temperature as you go down in mines, and the conclusion has been come to that the temperature rises one degree Fahrenheit, sometimes in sixty and sometimes in 100 feet. There is a mine in Cornwall in which he had walked in a stream of water at the bottom actually scalding to the legs ! and everybody knows what quantities of water there are in the hot springs. And then there is the great display of the volcanoes, which come from a great deal of heat somewhere ; and in places where volcanoes are extinct we can trace a sort of basaltic con- tinent, so to speak, up to the very mouths of the craters from which the lava has come. So that there has been in all former ages undoubtedly much more heat than at present. There was another matter on which he would desire to speak, but with no great boldness, and that was the change in magnetism. The subject of terrestrial magnetism is one of the most obscure in the world ; nevertheless, looking at the direction in which it always is towards the colder parts, and tracing its general phe- nomena, it may be effected by thermo-electricity, and tliat may be produced by the constant wear going on in the interior of the earth, where the fluid lavas are con- solidating themselves. Within a few years the voyage of the Challenger has been made, and he had little hesita- tion in saying it was one of the most important in the scientific history of the world. In crossing the great seas they sounded to great depths, and measured in a satisfac- tory way the temperature of the water down to the depth of five miles. They always came to cold at the bottom ; and there are great controversies whether the cold can come in deep sea streams from the frozen regions of the north. He thought that had some influence ; but he thought the bottom of the water and the ground at those great depths is cold — he did not think that part of the earth partakes of the same heat as other parts ; that he only expressed as his opinion, in which, of course, he might be met by the disbelief of a great many persons. That was the state of things as we know it regarding the temperature of the earth — that there is evidence everywhere that there has been enormous heat almost all over the earth. Some parts of the crust of the earth under the deepest seas are still perforated by volcanic islands. In some places the heat comes very near the surface. That he looked upon as an important fact, leading them to a theory of what the state of the earth really is. On entering upon a matter which was undoubtedly one of the boldest speculations in modern science, which was the formation of the earth — he could not say its crea- tion, but the way it got into its present shape — he had to premise that the theory on which he had to speak, which is known as the nebular hypothesis, is the conception of a very bold and vigorous intellect indeed. Laplace it was who remarked that all the planets and satellites revolved in the same direction round the sun, and all of them turned on their axis in the same direction : and it was difficult to deny that there must be some general cause for this. It naturally occurred to Laplace that if we can find something which is contracting its dimen- sions, and which has a little rotation to begin with, then with every contraction of dimensions that rotation would become more rapid, till it might go to any degree, depend- ing upon the condensation of its various parts and its density before. Then can we come to look at any matter which is being thus condensed, and which might so form systems such as ours, with sun, planets, and satellites ? There are a series of bodies in the sky which did not attract much attention in former days, mainly because telescopes were not so large, but which are now catalogued by thousands. These are the nebulae. The name denotes their cloudy appearance. They are small bodies among the stars, sometimes appearing to have stars in them, or to be connected with stars, and sometimes not. They have the strangest and most capricious shapes imagin- able. If this nebula is contracting its parts together so as to form a world, that rotation in the course of conden- sation will become so rapid that it may form suns and planets and earths around it ; and on this supposition there is no difficulty in making a complete solar system cut of such a mass as that of the nebula in Orion. Observations made lately by the largest telescopes — those of Lassell and Lord Rosse, both of which are re- markable telescopes of the largest class — have brought to light a number of nebulae possessing a spiral appearance ; and they seem to have some bearing on the supposition that the nebulas are contracting and getting into a rotatory state. But these changes go on so slowly that they had not been able to answer with certainty for any of the changes of which he now spoke. The whole thing is theoretical, and yet, as it seemed to him, in the highest degree probable. Supposing this to be the case, these nebulae would rotate, and in their compression would get very hot. There is no doubt that condensation would produce enormous heat, and it seems we have there suffi- cient explanation of the great heat we find below the surface of the earth and in other places. We suppose that the stars generally have been formed from the condensation of nebulae; and there is a circumstance which was worthy mentioning. A series of observations founded upon optical experiments has come to light within late years which has done more to reveal the secrets of nature than anything before — this was by means of the spectroscope. By voltaic action sparks may be produced which derive their character — sparks like those of an electrical machine— in a great measure from the metals from which they spring. A spark springs from metal to metal, and the character of the metals gives different characters to the sparks. We have one set of these spectra produced by iron, another by nickel, others even by hydrogen gas, and so on, and these are observed and catalogued with great care. When we come to observe the light in the stars in the same manner, we find there are no two stars alike ; some of them have the same spectra as that given from iron, and others have spectra from a number of different things ; and we are actually able, by legitimate reasoning from this, to say from what the stars are made— what metals and other things they are made of, and, as a generat thing, there are no two stars alike. So that in this nebular hypothesis we are not bound to say that the nebulae are all of the same materials, and we conceive that by comparing the bodies which we know in the solar system with those of the stars, we may arrive at an idea of the variety of materials of which the planets are composed. We cannot find anything different in comparing the light of the planets, because they all derive their light from the sun, and they do not present any difference of appearance in the spectrum. But we can draw conclusions from their relative density. As he had said to them, the average density of the earth is probably five and a half tirties that of water. They knew 44 NATURE [May 9, 1878 that the sun is only once that of water. What the sun is he could not tell, biit it is a very poor light creature indeed. The density of Mercury is perhaps rather greater than that of the earth. The density of Venus is much the same as that of the earth, and the density of Mars is also much the same as that of the earth. Then after that comes a shower of little planets, about 200 of which have been observed up to the present time, and he could not tell Avhat they are made of. Then there are Jupiter and Saturn, which are no heavier than water. So that it appears clear that, assuming the forma- tion of these things by the condensation of nebulae, on the theory he had mentioned, the different parts of the nebulae which have contributed to the solar system are very different. Well, that being considered as established, it follows that in the constitution of our earth there may be parts of very different density. He should say that the high and prominent parts of the land are made of something light, and the heavy and dense parts are those covered by a considerable quantity of water, which have sunk deep into the central lava on which, he conceived, all things are resting. And now he had come pretty nearly to the end of his theory, and he would show them what he feared they would call an absurd representation of what he conceived the state of the earth to be. [The lecturer drew atten- tion to a diagram of an "ideal earth," roughly show- ing his theory — some parts of the crust of the earth being thick and coloured darkly to indicate density ; some thick and not so dense, and all admitting of vol- canic eruptions from the interior, which was represented as lava.] Remember that everything here is exaggerated. It is not intended to be a correct representation. It is a caricature of the most extravagant kind ; but if it con- veyed to them the broad ideas that had impressed them- selves upon his mind, it would be doing the right thing. He thought a large proportion of the centre of the earth is fluid and hot, and he thought that upon this there were certain divers classes of something like solid matter. In all these parts there are cracks or chinks through which volcanoes burst out where the cover of the earth is very thin. In some places you have two or three volcanoes together. There is one instance in Europe, where we hare Etna, Stromboli, and Vesuvius. In this diagram he had condensed to the best of his conjectural power his supposition as to what the state of the earth really is ; and if any one chose to find fault with it he would not quarrel with him. He only gave it as a sort of inference from a number of things he had said. A NEW INSULATING STAND ^ CIR WILLIAM THOMSON has frequently dwelt on *^ the great importance of insulating, with the utmost care, any apparatus intended fo;r researches relating to static electricity ; he has shown that the atmosphere and other gases have but little effect in dissipating an electric charge, even when moist, and that it escapes mainly in consequence of the deposition of a layer of moisture upon the insulating supports which renders their surface con- ducting. In all Sir W. Thomson's electrometers there is an arrangement for drying the insulating surfaces by means of sulphuric acid, either free or absorbed by pumice. This method admits of very general applica- tion : — Any body, as for example apparatus constructed for the observation of atmospheric electricity, may be most perfectly insulated by supporting it on glass rods inserted in glass cylinders containing free sulphuric acid or pumice moistened with it. In order to do this the lower end of the rods must be either inserted into cylinders of lead or else fixed to the bottom of the jar by means of a substance not acted upon by sulphuric acid, for example, meked sulphur or paraffin ; melted sulphur is liable, on account of its temperature, to crack the jars, ' By M. E. Mascart, Professor of Physics, College de France, Paris. notwithstanding the precaution of previous heating* paraffin, on the other hand, softens in the course of time> and the glass rods do not retain their vertical position- Notwithstanding these disadvantages excellent insulators may be thus extemporised as occasion may require. For permanent use it is advantageous to employ insu- lators specially constructed, as shown in the accompanying figure; it consists of a bottle having a narrow neck, through which passes a tubular continuation of the Ijottom, about 4 mm. less in diameter than the internal diameter of the neck, so as to leave a space of 2 mm. (about) between them. The top of this hollow rod is closed, in order that a brass tube may be cemented upon it, into which may be screwed any apparatus, as, for example, a disc as shown in the figure, a sphere, a crutch on a hoop, &c., &c. In the shoulder of the bottle is a neck, closed with a ground-glass stopper, through which sulphuric acid may be poured, in the first instance, and renewed from time to time. As the space between the hollow rod and the neck of the bottle is very small, the air in the bottle does not change very rapidly, and the sulphuric acid remains efficient for a long time. It is only necessary to run off a portion of it occasionally by means of a siphon, and to add fresh ; as this may be done without disturbing the apparatus, the insulation may be maintained for any length of time. Moreover, for an insulator to be used occasionally, an addition is made of a vulcanised rubber cap, which slides on the glass rod to close the neck of the bottle when not in use.^ A double pendulum of pith balls supported by such an apparatus maintains its divergence, after being charged with electricity, for a very long time, even in a theatre filled with an audience. One may show by a simple experiment the great efficacy of this apparatus in comparison with insulators of glass exposed to the air, even when carefully varnished with shellac. If a pair of pith balls, suspended by a thread of cotton, is hung upon the latter support, and the metallic foot is placed on an insulator, and connected with a charged condenser, no divergence of the pith balls occurs in the first instance, but little by little the elec- tricity is propagated along the glass rod, and then the threads near the support begin to separate, and soon after the balls diverge and remain at a certain distance from each other. The electrometers of Sir Wm. Thomson are sometimes so perfectly insulated that the loss of a charge of elec- tricity does not amount to y^oth part in twenty-four hours. By means of the insulator described above, one may obtain an insulation of like order for bodies supported m the open air, and thus diminish to a great extent one of the chief sources of error usually met with in experi- menting with static electricity. ^ These may be obtained of various sizes, one litre, half -litre, quarter- litre capacity, at Alvergniat Freres, lo, Rue de la Sorbonne, Pans. May g, 1878] NATURE] 45 RHEOSTATIC MACHINE IT is known that Franklin made use of a series of Leyden jars or fulminating plates, arranged in the form of a cascade, to obtain strong discharges of static electricity ; that, on the other hand, Volta, Ritter, Cruik- shank, &c., were able to charge condensers by means of the pile, and that these results gave rise to researches, conducted both by calculation and experiment, on the part of a great number of physicists. I have been led to study, in my turn, the static effects of voltaic electricity,- by means of a secondary battery of 800 couples which I at present possess ; and I have de- vised an apparatus which shows the intensity that these effects may acquire. After having proved how easy it is with this battery to charge rapidly an insulating plate condenser, sufficiently thin, of glass, mica, guttapercha, &c., I combined a cer- tain number of condensers, formed by preference of mica covered with tinfoil, and arranged them as couples of the secondary battery itself, so as to be easily charged in quantity^ and discharged in {ension. All the pieces of the apparatus must be carefully insu- lated. The commutator is formed of a long cylinder of hard caoutchouc, provided with longitudinal metal- lic bands, intended to unite the condensers at the surface ; and traversed at the same time by copper wires, bent at their extremities, for the purpose of uniting the con- densers in tension. Small plates or metallic wires formed into springs are placed in connection with the two arma- tures of each condenser and fixed on an ebonite plate on each side of the cylinder, to which a rotatory movement can be given. If we put the two sides of the apparatus into commu- nication with the secondary battery of 800 couples, even several days after having charged it with two Bunsen elements, and if we set the commutator in rotation, we obtain, between the branches of the excitator, on which the armatures of the extreme condensers abut, a series of sparks entirely similar to those given by electric machines provided with condensers. By employing an apparatus of only thirty condensers, each of three square decimetres of surface, I have obtained sparks four centimetres in length. The tension of a secondary battery of 800 couples is not necessary to produce marked effects with this appa- ratus. By putting in action only 200 couples, we have sparks of eight millimetres, and we may, without doubt, by diminishing still more the thickness of the insulating plates and multiplying the number of condensers, obtain effects with a source of electricity of less tension. It is to be remarked that the discharges of static elec- tricity, furnished by this apparatus, are not in directions alternately positive and negative, but always in the same direction, and that the loss of force resulting from the transformation must be less than in the induction appa- ratus ; for, as the voltaic circuit is not closed a single instant on itself, there is no conversion of a part of the current into heat. We may maintain the apparatus a long time in rotation and produce a considerable number of discharges without the secondary battery appearing sensibly weakened. This is because each discharge employs only a very small quan- tity of electricity, and because, as above stated, the circuit of the battery is not closed by a conducting body. The electricity of the source simply spreads over the polar surfaces presented by all the condensers, in proportion as they are discharged. This emission constantly re- peated must nevertheless end by discharging a certain quantity of electricity ; and when the instrument is charged by a secondary battery, we must ultimately exhaust, under the form of static effects, the limited quantity of electricity which the current of the battery can furnish. Thus then, by another method than that of induction, properly so-called, by means of a simple effect of static in- fluence renewed without cessation, we effect the transfor- mation of dynamic electricity, so that this apparatus may be designated by the name of " rheostatic machine." Gaston Plant^ GEOGRAPHICAL NOTES The Berlin Geographical Society celebrated in charac- teristic German fashion the fiftieth anniversary of its foundation last week. Berlin, as our readers know, is not the only German city possessing a geographical society ; indeed it has two. In Hamburg and Bremen are two excellent societies of this class, while the Continent, generally, is overrun with them. Russia has about a dozen, Belgium has at least two, Brussels and Antwerp, Holland one if not more, France at least half a dozen, Italy two or three, and the Scandi- navian countries their own share. We do not consider it a disadvantage that in maritime countries there should be more than one geographical society, and we think it might be beneficial if even in our own country associations corresponding to the French societies of commercial geography were established in our chief ports, Liverpool, Glasgow, Bristol, Leith, Dundee. These might be branches of or affiliated to the London society, and might catch much that never reaches the latter. They might, moreover, do considerable service in encouraging the 46 NATURE l^May 9, 1878 merchant service to obtain and bring home information that would be useful to science, and might, by means of lectures and otherwise, foster a scientific spirit among our commercial population. Much good is done in this way, we believe, by the societies of Marseilles, Bordeaux, and Lyons. Two new geographical societies have, we learn, been established in France, at Metz and Montpellier. The French are evidently doing their best to remove the reproach so frequently cast at them, of being more ignorant of geography than even the English. That the Continental societies go in for earnest work is evident from the weighty journals published by most of them. The Mittheilungen of the Hamburg Society for 1876-77, for example, is a thick volume of 400 pages, containing a number of papers of considerable scientific value. Besides several papers on Central and South Arnerica, there is a long series of letters by Dr. Pfund, filling nearly half the volume, written during his travels in Kordofan and Darfur, along with Colonel Prout, of the Egyptian staff. Other African papers are by Dr. Paul Ascherson on his travels in the Lybian desert in 1876, and one of much value by Herr Fischer, on the present condition of the Galla Country. In the Deutsche Geographische Blatter, the organ of the Bremen Society, Dr. Oskar Lenz discusses at length the trade con- ditions in Equatorial West Africa, with special reference to Stanley's discoveries ; Dr. Lenz does not believe that the Ogovai is connected with the Congo. Mr. W. H. Dall is contributing to this journal a series of papers on his own and other recent researches in the Aleutian Islands, while Dr. A. Ziegler has an interesting paper on Regio- montanus and Martin Behaim. Turning to Italy the energetic Roman Society has begun the publication (apart from their always interesting Bo/tetmo) of Memori'e, containing at length the most important papers read at the Society's meetings. The first part contains a lecture by the president, Signer Cristifero Negri, on scientific geography, which shows what has more than once been said, that geography is really the meeting-place of all the sciences. Then there is a paper on the geographical distribution of camels, by Prof. Luigi Lombardini, and a well-arranged series of instructions to explorers by various specialists, edited by Signor A. Issel. Nor must we forget the American Society, with its seat at New York, and which is the medium for a good deal of valu- able information that might not otherwise reach the light of day. Chief-Justice Daly's presidential address always contains an admirable and exhaustive summary of the year's work ; and this year it is quite as full and interest- ing as usual, nothing in the domain of geography of any importance remaining untouched, special prominence being of course given to the various surveys of the United States. Thus it will be seen, that under the name of geography, much varied and really valuable work is being done, and that dilletanteism has really but a small place in it, at least abroad. An expedition, comprising twenty-five miners and others, has started for New Guinea. This news is tele- graphed from Sydney, and we earnestly hope that the expedition is under proper direction, both for the sake of the natives, who have so far been friendly to white men, and for the sake of further scientific discovery. THE TRANSIT OF MERCURY HTHE weather on Monday was so unfavourable that -■• the observations of this interesting phenomenon ■were mostly unfortunate in England. In France some valuable observations seem to have been made. Our Paris Correspondent writes that the observations taken by M. Janssen at Meudon Observatory were wonderfully suc- cessful considering the state of the atmosphere. He was able to make use of spectrum analysis in order to deter- mine the composition of Mercury's atmosphere. He was able to see Mercury before it had begun to make its first entrance on the disc. This observation is a confirmation of the phenomena observed in 1874 at Yokohama on the occasion of the Transit of Venus. Two photographs are excellent, and will lead to a determination of the diameter of the planet. At the Paris Observatory the transit was also seen. When Capt. Mouchez saw Mercury the disc had been indented to the extent of 1" of degree, about |th diametes of Mercury. When it was seen by the brothers Henry it was half on the disc. The difference of time is about 10" later at the National Observatory. The brothers Henry also saw the interior contact at about 3h. 23m. and some seconds. The exact time cannot be given yet. The con- tact was decidedly bad owing to the clouds. At Algiers and Bordeaux the observations were bad. At Ogden, Utah, United States, the delegates sent by the French Government, M, Andr^, of Lyons, and M. Angot, of Paris, obtained seventy-eight photographs of the transit. Satisfactory observations and photographs of the transit were taken at the Government Observatories at Washington and West Point, U.S. Mr. J. J. Cole writes to the Titnes from Mayland, Sutton, Surrey, that the sun was clear from 3.5 to 3.25, and the whole ingress was steadily observed with a refractor of 6 inch aperture and three others smaller. The Greenwich mean times of external and internal contact were taken, and were confirmed by Mr. Bawtree near with unexpectedly small differences. At Aberdeen the transit was observed by Lord Lindsay, Mr. Ranyard, Dr. Copeland, Mr. Carpenter, and Herr Lohse, and photographed by Mr. Davis, A thin cloud covered the sun at the time of first contact. No ring of of light was seen round the part of the planet off the sun' s disc. External contact was observed spectroscopic cally by Lord Lindsay, who detected the approach of the planet by the eclipse of the C line thirteen seconds before its limb encroached upon the continuous spectrum of the photosphere. Mr. Ranyard observed the continuous spectrum below C line, but saw no trace of the planet until it was on the sun's disc. No change in the solar spectrum was observed at the limb of the planet. Dr. Copeland, Mr. Carpenter, and Herr Lohse obtained both contacts and measures of diameter. Mr. C. G. Talmage writes as follows to the Times from Mr. Barclay's Observatory, Leyton, Essex ; — " Owing to the prevalence of clouds the times of ex- ternal and internal contact at ingress were not observed here. The first view I obtained was at 3.43, Avhen Mercury had advanced some considerable distance on the sun's disc. The duration of clear sky was then so short that there was not sufficient time to obtain micrometrical measures of distance from the sun's limb. For about eight or ten seconds the sky was absolutely clear, and then I noticed that Mercury was surrounded by a bright ring, dark- ening off to the periphery, which was exceedingly well defined. The distance between the limb of Mercury and periphery of ring was about two-thirds of the planet's diameter. I used the full aperture of ten inches, with a diagonal power of eighty." DE CAILLETET'S APPARATUS ■\"\/E have already (vol. xvii. p. 265) spoken at length * * of M. Cailletet's method of liquefying the last of the gases, and at the same time we referred to the fact that students of science in France had not been for- gotten by the accomplished experimenter. We described briefly a portion of an apparatus for use in laboratories, for this experiment, and are now able to give an illus- tration of the complete laboratory apparatus as manur factured by Ducretet and Co., of Paris. The figure shows the apparatus one-eighth the size of reality. May 9, 1878] NATURE 47 To work this apparatus it is necessary to take off the liquefying tube T and all the pieces of the upper part ; also the lateral screw e' and its tube A' ; then, after having screwed on to the joint R the piece N, which serves as a stop-valve, the mercury should be turned dry and quite pure, into the wrought-iron reservoir B, up to the level of the edges N n'. The sides of this iron reser- voir are very resistant and are able to support strong pressures. The tube t having been filled with gas for liquefaction, it is gently forced into the mercury of the reservoir B ; the part N being taken out, the mercury which flows out is collected. When the tube A rests on the leather of the bottom of the length of the reservoir, the screw e' is re-screwed very tightly. The apparatus is inclined a little to get rid of the excess of mercury, in order that its level may remain below the lateral hole by which the pressure is introduced. The support S with refrigerating envelope M is then re-screwed on the upper part of the ajutage A ; it rests- Au T 1 execution upon leather. The safety-bell-jar c is movable; it is intended to stop the pieces of glass should the tube T be broken. The stop-cock r lets the water flow from the envelope M. The lateral screw with the tube a' is re- fixed, to which is soldered the small metallic tube T v, by which pressure is introduced. The hydraulic pump, which Ducretet and Co. have constructed specially for this apparatus, is for the pur- pose of compressing water about the mercury contained in the reservoir. The two valves E e' may be introduced by the orifices closed by the screws E e' ; the valves may be thus tested and easily changed without undoing any part. The reservoir of water R is placed outside ; it is then easily seen to and kept full. Before setting the hydraulic pump to work, we with- draw as completely as possible the screw-plunger piston V by moving the fly-wheel. The action of the lever E enables us to obtain easily a pressure of 200 atmospheres. This pressure may then be increased by the gentle intro- duction of the plunger-piston v. The liquefying tube T is of thick glass ; it has a resistance of about 400 atmo- spheres, but it is better not to exceed a pressure of 300 atmospheres. The second screw v' is intended to pro- duce expansion. NOTES One of the most effective methods of acquiring a headache is a good round of sightseeing, especially in a museum, collection, or picture-gallery ; it is quite a comfort to get among a collection of any kind, the sight or catalogue of which does not make one ill by anticipation. Happily the headachy feature is generally absent from the collection of objects exhibited at the Royal Society conversazioni, and in this respect and because of its great interest, the collection brought together last Wednesday week was quite a model. Prof. Snellen's two modes of testing for colomr-blindness ought to have been the first thing looked at, because then the guests would have been in a position to estimate the value of their observations. The inspection caused much amusement, and in some cases astonishment. The "Mechani- cal Chameleon," to exhibit the mixture of two colours in any proportion, was interesting, as was also Woodward's new rectangular prism illuminator, to be used with immersion lenses. The President's photographs of scenes and objects in the Rocky Mountains were specially attractive. Other objects which attracted considerable attention were — A large Holtz electric machine (by Ladd) consisting of twelve rotary and twelve stationary plates,, thirty inches diameter, exhibited by Mr. W. Spottiswoode, Treas.R.S. A microspectroscope with improvements,— (i> quick movement of the slide carrying the slit; (2) scale for registering position of slit; .(3) arrangement for comparing three spectra, and for splitting a single spectra ; (4) new form of 48 NATURE [May 9, 1878 comparison stage, made by Mr. A. Hilger. A dynamo-electric machine, speed 800 revglutions, power 175 H.P. required to work it, effect 1,200 candles' light, exhibited by Messrs. Siemens Bros. The telephone harp, with visible records of sound through vacuum tubes, exhibited by Mr. F. A. Gowei-. Apparatus for showing figures in light from vibrations caused by sound, exhibited by Mr. Henry Edmunds. A metallic thermo- meter, invented by Mr. H. Bessemer ; and apparatus for the automatic registration of the number of hours of sunlight, made for Kew Observatory, exhibited by Mr. J. Browning. A phoneidoscope, an instrument for observing the coloured figures reflected from liquid filters under the action of sonorous vibra- tions, made and exhibited by Tisley and Co. Composite portraits, made by combining the likenesses of different persons into a single resultant figure : (i) optically, {2) photographically, exhibited by Mr. Francis Galton, F.R.S. ; we hope to publish a paper on the subject next week. We need not say that the phonograph in operation, under the superintendence of Mr. Preece, was specially attractive, and that Winkler's Lunar Landscape, and the beautiful photographs and paintings exhi- bited, lent a delightful variety to the collection. This fine spring must render folks eager for their summer holidays, and many a plan must be thought over under its influ- ence. Mr. Marshall Hall suggests that if one or two points and dates were fixed as rendezvous, mineralogists, geologists, botanists, entomologists, ei hoc genus omne, might be very likely to accumulate and compare notes. For one such point Mr. Hall suggests the Hotel Bauer, at Sien-e in the Valais, which can be reached in two day from London, vid Paris, Pontarlier, Vallorbe, Lausanne, &c. For examination of the Lotchenthal and the Val d'Anniviers this would be a good place to start from, whilst travellers having mountain business could go about it north to the Oberland and south to the Pennine Alps. " If any other man knoweth a better place let him impart." Any one who has seen the graceful snout of a salmon or a trout, especially if he has looked upon it after an hour's exciting spin on a river or Highland loch, will be filled with disgust and, if an angler, with grief, on beholding the horrible head of a smolt figured in the Gardeners' Chronicle of May 4. It is posi- tively loathsome. And this is the effect of the disease which has been proving so destructive to the helpless creatures in some of the Northern rivers, especially the Esk, Eden, Kent, and even the Tweed we believe. Mr. Worthington Smith has been making some inquiries into the nature of this disease which is killing not only salmon and trout, but eels, flounders, and other fish. He finds it to be a fungus {Saprolegnia ferax), which attacks mainly the head, tail, and fins. The scales appear to be covered with a fine white cottony bloom, which at length blinds the fish, envelops the gills, or even entirely closes the gills and mouth. Mr. Smith thinks the reason for the extraordinary abundance of the fungus this year is the unusual mildness of the winter. It seems only to attack the fish in fresh water, those in the estuaries escaping. We trust for the sake of our food supplies as well as on account of our genial friends the anglers, not to mention the poor fish themselves, that some means will be found of preventing the spread of the disease. Prof. Wiedersheim, of Freiberg University, writes us that through the kindness of Prof. Rutimeyer, he is in a position to describe a Labyrinthodont fi'om the Trias, belonging to the palaeontological collection at Basel. While hitherto nothing but the skull and some of the bony scales from the epidermis have been known, this specimen is completely preserved, whereby we obtain for the first time a full and clear insight into the organisa- tion of the entire skeleton of this remarkable amphibian. But not only the skeleton with head, vertebral column, the shoulder and pelvis, down to the last phalanges of the fingers, are on view at the museum at Basel, but also a fine cast of the cranium and the spine, by which the extremely-low organisation of the central nervous system of these animals is proved. Prof. Wiedersheim will publish a minute description of the remains in the Reports of the Swiss Paloeontological Society. At the close of 1877 the amount subscribed for a statue to Linnreus was 44,276 Swedish crowns. This sum being insuffi- cient, further contributions were obtained in Stockholm of 30,000 crowns, and the municipality of that city has undertaken to defray the expense of the pedestal and of the erection of the statue. The total sum available is estimated at 100,000 crowns (5. 500/). The Berlin Ethnographical Museum has lately been enriched by a valuable collection of all the articles used by the two tribes of the Ostiacs and Samojedes in North Siberia. These objects were collected by Dr. Finsch during his voyage in 1876, and will soon possess no slight value, as the peculiarities of these people are rapidly vanishing in contact with Russian civilisation. Prof, von Siebold, one of the oldest and best known of German zoologists, celebrated last week in Munich the fiftieth anniversary of his reception of the doctoi-'s degree. The King of Bavaria presented him, on the occasion, with the cross of the Order of St. Michael; deputations were sent by the Munich University and Academy of Sciences, and greetings were sent by numerous foreign universities and societies. The Berlin Royal Academy of Sciences has granted the sum of 400 marks (20/.) to Dr. Ludwig Graff, Professor of Zoology at the Forest- Academy of Aschaffenburg, for the completion of his "Monograph of Turbellaria.^^ Dr. Graff is now at work at the Zoological Station of Naples. At the annual meeting of the Royal Institution of Great Britain the Annual Report of the Committee of Visitors for the year 1877, testifying to the continued prosperity and efficient management of the Institution was read and adopted. During the last twenty-five years the number of members paying annually (five guineas) has increased from 344 to 544. The real and funded property now amounts to above 84,500/., entirely derived from the contributions and donations of the members. Forty-one new members paid their admission fees in 1877. The principal officers were-re-elected. At a special general meeting of the Birmingham Natural History and Microscopical Society, held on the 30th ult., Dr. Cobbold, F.R.S. , was unanimously elected an honorary vice- president of the Society. M. F. SoENSON has presented to the Swedish Academy the results of his experiments on the electric conductivity of solu- tions of various alums. These show that in all cases the con- ductivity increases directly with the concentration of the solution, and that while less intense than in solutions of the simple alka- line sulphates, it is always more intense than in solutions of aluminium sulphate. The green modification of chrome-alum possesses a greater conductivity than the red variety. The French Association for the Progress of Sciences is pre- paring for its next session, which will take place on August 28 at Paris. The Bureau has been completed and is composed as follows : — President, M. Fremy, Professor of Chemistry at the Polytechnic School and Museum of Natural History; Vice-presi- dent, M. Bardoux, the Minister of Public Instruction; Secretary M. Perrier, of the staff, Dii-ector of the Ordnance Survey, Member of the Bureau des Longitudes] and Council of, the Observatoiy ; Vice-secretaiy, M. Comte Saporta, Correspondent of the Insti- tute ; Treasurer, M. Masson, the scientific publisher ; Secretary of the Council, M. Gariel, Engineer of Ponts et Chaussees. The session will take place at the Ecole des Beaux Arts, a very exten- A. ay 9, 187S j NATURE 49 sive building containing many magnificent rooms for sections. For all inquiries relating to the Paris meeting letters must be directed to M. Gariel, Secretary of Council, 76, rue de Rennes, Paris. i At the general monthly' meeting of the Royal Institution of Great Britain, the Secretaiy announced that the managers had granted the use of the lecture-theatre to the Sanitary Institute of Great Britain for their anniversary meeting on July 3 at 3 o'clock, when an address would be given by Mr. Frank Buckland, M.A., on "The Pollution of Rivers, and its EflFects upon the Fisheries and the Supply of Water to Towns and Villages." Messrs. Blackwood have published a fifth edition of Prof. H. A. Nicholson's "Manual of Zoology." While the plan of the work is essentially the same as in former editions, the entire work, the author states, has been submitted to careful revision, and large portions of it have been almost entirely rewritten. A COMMITTEE has already been formed in Holland, tinder the presidency of Prince'Alexander_of the Netherlands, to celebrate, in a fitting manner, the 300th anniversary of the eminent philo- sopher and statesman, Hugo de Groot, who was born on April 10, 1583. A MEDALLION representing M. Thenard, the celebrated pro- fessor of chemistry, who was during a long time Dean of the Faculty of Sciences and Chancellor of the Paris University, has been sculptured on the walls of the Sorbonne courtyard. It was inaugurated on the occasion of the meeting of the Societes Savants. It bears the'date'of 1877, the centennial year of M. Thenard's nativity. M. Thenard died in 1857. The Jardin d'Acclimatation at Paris has just succceeded in obtaining an East Indian tapir, an animal rarely found in European collections, although the South American variety is comparatively common. An interesting work has just appeared in Stuttgart from the pen of Dr. R. Andree, on " Ethnographic Parallels and Com- parisons." The author has chosen over twenty various subjects, and has gathered together on these topics an enormous amount of material from all the races on the globe. Among these subjects are constellations, cairns, "measures of value, mothers- in-law,- the vampyre, skull worship, the umbrella as mark of dignity, &c. In view of the rapid invasions of European culture in every direction, the author considers it of the utmost importance to complete as rapidly as possible the collection of all objects necessary to preserve a complete picture of the material and intellectual condition of the uncivilised peoples now existing, Mr. Lugger, the curator of the Maryland Academy of Sciences, left Baltimore on April 4 for the purpose of prose- cuting explorations in the West Indies and in Demerara in be- half of the Academy. In the course of his mission he will en- deavour to prociure living plants for the conservatory of Druid Hill Park and material for the zoological investigations of the Johns Hopkins University. Despite numerous misfortunes, Berlin still continues to sur- pass all other European cities in its collection of anthropoid apes. The Zoological Gardens have just received from Borneo a healthy pair of orang-outangs, which, added to the one already in their possession, make an exhibition of rare interest. On the evening of April 23 Vesuvius showed signs of internal disturbance, sending up a column of flame at short intervals from the crater. A French physician. Dr. Quimus, has lately made an elabo- rate study of a new disease, prevalent among telegraphic employees, and closely resembling writers' cramp. It is more common among the female operators. From the last quarterly list of the members of the Institution of Civil Engineers, we gather that this increasing body now con- sists of 1,033 members, 1,759 associates, and 16 honorary members, together 2,808 ; besides a class of ^students attached numbering 520. The German Fischerei-Verein, of the activity of which we have made frequent mention, is engaged now in introducing the Californian salmon extensively into German waters. Of 300,000 eggs sent across the ocean, 25,000 arrived in good con- dition, and the resultant fish have been divided between the rivers of the Danube valley and_ those of the Rhine. 300,000 young eels from Normandy are being introduced into the Prussian streams. Amongst the few halls of the Paris Exhibition which can be considered as quite ready we must notice the excellent school exhibition of the City of Paris, which is situated in the central part of the palace. A NEW remedy for diarrhoea in men and animals is said to have been discovered in New Zealand, where it has long been in use among the Maories. It consists in a decoction made by pouring boiling water on the green leaves of a shnib called roromiko by the natives. The liquid, though slightly bitter, is said to be not unpleasant to the taste. It is asserted that two doses of this decoction will always effect a cure even in bad cases. A Japanese (native) paper states that a resident at Osaka has been endeavouring to manufacture oil from cnide camphor, for which purpose he has built a large factory in that town. The oil he makes is described as being cheaper and better for piu^poses of illumination than kerosene. One of the curiosities of industr}', according to the yapan Herald, is the manufacture of boots by the Japanese for sale in the United States, a trade which is of quite recent origin, but has already attained considerable proportions. Oddly enough most of the leather used is imported into Japan from the United States. A product of the South Sea Islands, "copra" which is the dried kernel of the cocoa-nut, is being turned to a new account. Hitherto it has only been used for making oil, but now it has been discovered that the residue, after that process, is valuable as food for cattle and sheep. There have been not a few signs recently that Spain is awaken- ing from her long lethargy with regard to progress of all kinds, aiid one more comes to us in Nos. 6 to 25 (with the exception of No.. 13, which has not come to hand), of the Boletin de la Inshtiicion Libre de Ensenanza (Madrid), which make us acquainted with the Proceedings down to February 28. These recent numbers give us information as to the rules and objects of the Institution. By Article I the Institution is "Consagrada al cultivo y propa- gacion de la ciencia en sus diversos ordenes." By Art. 3 the number of Fellows is unlimited. By Art. 15 "La Institucion es completamente ajena a todo espiritu e interes de comunion religiosa, escuela filosofica 6 partido politico ; proclamando tan solo el principio de la libertad e inviolabilidad de la ciencia y de la consiguiente independencia de su indagacion y exposicion respecto de cualquiera otra autoridad que la de la propria conciencia del Profesor, unico responsable de sus doctrinas. Art. 16 : La Institucion establecera, segun lo permitan las circum- stancias y los medios de que pueda disponer : i , Estudios de cultura general (6 de segunda Ensenanza) y prof esionales, con los efectos academicos que les concedan las leyes del Estado ; 2. 50 NATURE [May 9, 1878 Estudios superiores cientificos ; 3. Conferencias y cursos breve*^ de caracter, ya cientifico, ya popular; 4. Una biblioteca y los Gabinetes dotados del material correspondiente ; 5. Un boletin para publicar sus documeutos oficiales y trabajos cienti- ficos ; 6. Concnrsos y premios, y cuanto contribuya a promover la cultura general y sus propios fines." These extracts from the statutes, ratified May 31, 1876, will sufficiently show the aims of the Institution, and show also what is being done for the cultivation of science in Madrid. Running through Nos. 10-15, 18-21, is a list of 728 shells, in the natural history cabinet, arranged on the method of Dr. Woodward's "Manual of Con- ■chology," and in Nos. 22, 23 are catalogues of plants in her- baria from the Province of Avila and from the Philippine Islands. In Nos. 24, 25, a classification of rock specimens. The contents of the several numbers are of the same general character as we indicated in our former notice. The papers on Haeckel's morphology are continued, and the same professor (A. G. de Linares) has papers on the classification of geometri- cal figiu-es, and on some recent publications on crystallography andmineralogy. The syllabuses are given of courses of lectures on two or three languages, on mathematics (arithmetic and synthetic •geometry) and other subjects. We can only wish success to this the first (we believe) society, of the kind that has been formed in Spain. No plant perhaps has a more varied adaptation than the bamboo. In every country where these gigantic grasses grow they are put to a multitude of uses. It is not then because the ■bamboo is incapable of being converted to any other use that so much attention has been given to it of late with the view of turning it into a source of supply for paper material. It is more on accotmt of its rapid growth, the ease with which it can be propagated and its abundant yield, together with its wide geographical range, that such interest has been roused in it, for the several species of bamboo are found in most tropical parts of the world. If, however, it should become a regularly recognised paper material there is no doubt that our supplies would be obtained chiefly from the East and West Indies. With regard to its growth in the latter country there seems to be a prospect that it may prove successful for cultivation in plantations specially formed for growing the plants for paper stock. There are, of course, extensive natural resources of bamboo, but it is thought that by cultivation and a system of irrigation the yield would be greatly increased and the cost of keeping up such a plantation would, after the first two years, be almost nil. It is by no means improbable that the bamboo will in the course of time become an important paper-making commodity. A STRANGE meteorological phenomenon was recently observed at Logelbach, in Upper Alsatia. The rising sun seemed to be surrounded by a vast column of fire. An eye-witness describes the occurrence in La Nature. When he began his obser- vations, the column had already reached a height of 25 or 28 degrees. Its breadth remained constant, and amounted to 2 or z\ degrees. Its colour was greyish red, and at its upper end orange ; the dull and cloudy sky formed a fine contrast with the brilliant phenomenon. From 6.30 a.m. tiU 7 o'clock its brilliancy remained much the same, while its extent towards the west increased by about 4 or 5 degrees. At 7 o'clock the sun's disc appeared above the horizon, and its tint was an intense red. The whole sky now seemed to be a gigantic rainbow, all the shades of which appeared in horizontal layers, forming a splendid background to the bright red and orange vertical column. A minute later the sun lost its red tint and the column gi-adually decreased ; for five minutes it formed a band of 5 degrees in height, and then disappeared altogether. Decade V. of the "Prodromus of the Palaeontology of Victoria," by Mr. Frederick McCoy, of the Geological Survey of Victoria, deals, by means of well-executed lithographic illustrations and text, with numerous fossils of the tertiary and Upper and Lower Silurian formations. The recent numbers (26-31) of Bentley and Trimen's "Medi- cinal Plants " fully maintain the excellence of the earlier ones. Among the admirable plates of well-known plants in these numbers may be mentioHed those of Aconitum ferox ; the opium- poppy, Pajiaver somniferum ; the liquorice, Glycyi-rhiza glabra ; the indigo. Indigo/era tindoria ; the camphor, Cinnamonum camphora ; and the sabine, ytiniperus sabina. The only one in these numbers which does not strike us as so happy, is that of the common marjoram. Origanum vulgare. We regret that the name of M. Milne-Edwards somehow got among the catalogue of the eminent men whom we named last week as having gone over to the majority during the existence of Nature. We are glad to say that M. Milne-Edwards, though as old as the century, is as active as ever. The addition to the Zoological Society's Gardens during the past week include a Lion {Fells led) from Africa, presented by Mr. J. D. Massey ; a Vervet Monkey {Cercopithecus lalandit) from South Africa, presented by Mr. G. W. Twining; a Ma- cacque Monkey (Macacus cyttomologus) from India, presented by Mr. J. M. Neil ; a Black-eared Marmoset (Hapale penicillata) from South-East Brazil, presented by Mr. Walter M. St. Aubyn; a Common Cormorant {Phalacrocorax carbo), Euro- pean, presented by Lord Braybrooke ; four Green Lizards {Lacerta viridis) from the Isle of Jersey, presented by Mr. F. E. Lawder; a Black Ape {Cynopilhecus niger) from the Celebes, a Brazilian Tree Porcupine {Sphingurus prehensilis) from South America, deposited ; two Lesser Birds of Paradise {Paradisea papuana) from New Guinea, two Black Storks (Ciconia niger) European, purchased ; two Black -faced Spider Monkeys (Ateles ater) from East Peru ; a Common Cassowary {Casuarius galeatus) from Ceram, a Golden-winged Woodpecker (Colaptes auratus) from North America, received in exchange ; a Great Kangaroo (Maeropus giganteus), an Eland {Oreas eanna) born in the Gardens. ACADEMIC LIBERTY IN GERMAN UNI- VERSITIES'>■ T N taking possession of the high functions to which the vote of my colleagues has raised me, my first duty is to renew here, publicly, the expression of my thanks towards those who have given me this proof of their confidence. Its value is all the greater in my eyes because it has been given to me notwith- standing the few years I have passed among you and notwithstand- ing my function of professor in the natural sciences which form, in the curriculum of university education, a foreign element, the introduction of which has caused the modification of several points in the ancient organisation of the faculties, and will yet induce others in the future. The department of physics to which I have devoted myself is exactly that which contains the theoretical foundations of all the other branches of the natural sciences, and which presents in the most striking form the characteristic features of their methods. Thus I have several times already been compelled to propose to the University modifications in the rules previously followed, and I have had- the pleasure of being always backed by the hearty support of my colleagues and the University Senate. Since you have chosen me to direct the University during the course of the next year, it is a proof, in my eyes, that you do not regard me as a rash innovator. The object, the method, the immediate aim of the natural sciences may at first sight appear altogether distinct from those of the moral sciences; it seems to men accustomed to occupy themselves exclusively with the immediate expression and the proofs of the intellectual life, that they have nothing to learn from the results of these sciences, and that they have for them only a remote interest. But, in reality, as I have already ' Rectorial Address cf Prof. Helmholtz, F.R.S., at the University o Berlin. May 9, 1878] NATURE 51 endeavoured to show in my rectorial address at Heidelberg, there is a very close relationship between the two orders of sciences ; they pursue the same final end by processes which, at bottom, are the same. If the greater part of the researches in the natural sciences have not for their immediate object an intel- lectual advantage, on the other hand, it should not be forgotten, that the power of the pure intellectual method is here shown much more clearly, and a penetrating analysis of phenomena makes known the true and the false with much more precision than can be the case in the complex problems of the moral sciences. Side by side with the development of this new branch of scientific activity, almost unkno^vn in antiquity, the changes which have supervened in political, social, and even inter- national relations, also exercise an influence which must be taken account of. The circle of our students is enlarged ; the transformation of public life entails new exigencies ; the various branches of science are more and more subdivided ; it becomes necessary to add to libraries other means of study more and more considerable and more and more varied. It is difficult to foresee what new wants and what new exigencies we shall have to face in the near futiu-e. On the other hand, it is not only in our own country that the German universities have a place of honoiur : they attract the attention of the civilised world. Students speaking the most diverse languages flock to them from the ends of the earth. A false step may make us fall from -this high position, and it would afterwards be difficult to regain it. In these circumstances it is our duty to seek to discern clearly what has hitherto been the internal principle of the prosperity of our universities, what essential element of their organisation must be maintained intact as a thing sacred and inviolable, and in what direction our efforts should tend when reforms become necessary. I do not consider myself authorised to pronounce on these questions in a definitive manner. The point of view of each of us is necessarily a little exclusive ; the representatives of other sciences may, from other points of view, advance different considerations. But I think that, in order to arrive at definite and fixed conclusions, it is necessary that each one seek to express exactly what are his particular ideas on these questions. Over all Europe, in the Middle Ages, the universities had their origin in unions, free and private, of students grouped under the influence of celebrated masters. These unions regu- lated their own affairs. In recognition of the public services they rendered, the Governments soon accorded them guarantees, privil^es, and honours, notably the right of examining their members and of conferring academic degrees. The students of that epoch were, for the most part, mature men, who resorted to the universities for the purpose of being instructed and without any immediate practical end. Soon they commenced to send young men also, placed very often under the care of older students. Each university was divided into more restricted associations, known under the names of Nations, Bourses, Col- leges. The older graduate members of these associations, the Seniores, administered the special affairs in each of them, and met in general assembly to discuss the affairs conmion to all the university. We may see even to-day in the court of the Uni- versity of Bologna the list and the arms of the members and Seniores of the various Nations which formerly composed it. The oldest graduates were regarded during their whole life as members of the association ; they preserved their right of voting, a custom which has been continued almost to our own days, or which exists still in the college of the doctors of the University of Vienna and in the colleges of Oxford and Cambridge. V Thus, a free union of independent men, all brought together, masters and pupils, by the pure love of knowledge, the one anxious to know the treasures of intellectual culture left by anti- quity, the other labouring to communicate to the new generation the enthusiasm for the ideal which had kindled their souls ; such was the origin of the universities, whose organisation, in its principles and its details, was founded on the most complete liberty. We must not, however, believe that they admitted the liberty of education in the modem sense of the term. The ma- jority showed itself very intolerant to differences of opinion. More than once those who found themselves in the minority were compelled to quit the university. This occurred not only when the Church intervened or when political or metaphysical ques- tions were agitated. The faculties of medicine themselves, and at their head that of Paris, the most celebrated of all, would not tolerate any deviation from what they regarded as the doctrine of Hippocrates. They expelled from their midst those v/ho practised the medicine of the Arabs or who admitted the circu- lation of the blood. The transformation which led the universities to their present situation was due principally to the action of the State, which provided them with material assistance, and, in exchange, assumed the right of interfering in their affairs. The progress of this development was not the same in the various countries of Europe ; it was determined in part by the political situation, in part by the peculiar character of each nation. Those which underwent the fewest changes were the two old English universities of Oxford and Cambridge. Their large revenues and the political tendency of the English to respect all acquired rights have preserved them almost absolutely from alteration, even on points where changes would have been extremely desirable. These two universities preserve even to day the character of schools intended to recruit the clergy, formerly the Roman Catholic clergy, now that of the Anglican church. The laity participate in the education which is there given, in so far as that may contribute to general intellectual cultiu-e ; but they must submit to the discipline and the mode of life which were formerly considered suitable for yoang clerics. They live together in kinds of colleges, under the surveillance of a certain number of elder graduates (Tutors) belonging to the same college ; for the rest they follow the manners and customs of the wealthy classes of England. They can only go about in a certain costume, of a somewhat ecclesiastical cut, with special insignia, indicating not only their academic grades, but also their social rank. The education, in its basis and method, is that of our gymnasia, but a little more developed ; in certain points only it approaches more the repditions organised in our universities ; thus, it is limited to the programme required for examination, and the students are bound to study certain books, indicated beforehand. The work of the students is controlled by very detailed examinations, which must be passed in order to obtain the academic degrees, and in which very special knowledge is required, but only in certain very narrow subjects. All the old degrees of the academic dignities, the baccalaureate, the licen- tiate, the mastership in Arts, the doctorate, are obtained by tests of the same kind. The lessons are generally given by the Tutors above referred to. But they do not teach by virtue of an official delegation like the masters in our gjmanasia ; there are rather special masters chosen by certain groups of students. There are few professors, and they give only a small number of lectures to a scanty auditory, and usually on a very special sub- ject. These lectures do not constitute an essential part of the education ; they serve at the most to famish to some students, having a special interest to make great efforts, the occasion for more profound study. The various colleges are, moreover, com- pletely separated from each other ; the examinations, the confer- ment of degrees, the nomination of professors are the only matters common to the whole university. It is only quite recently that students not belonging to the Church of England have been admitted, and that some little attempt has been made to provide for professional education in law and medicine. Among the professors of the English univer- sities, there is a great number of very distinguished men, and who have a place in science. But the right of taking part in their election is not reserved to the Fellows actually forming a part of the corporation ; it belongs equally to all the former Fellows, even when they have no longer any connection with the university, when they have no interests in common with it, and when they may be engaged in the straggles of political and ecclesiastical parties. The result is that party considerations, personal connections, and friendship, often exercise more influ- ence on the elections than scientific merit. From this point of view the English universities have preserved all the intolerance of the middle ages. The professors are not requu-ed to reside in the university town ; they may fix their abode in any part of the kingdom ; they may even fill other functions at their convenience, often, for example, that of parish priest ; it is enough that they give their lesson at the university once a week, sometimes even more seldom. The English universities devote a very small portion of their enormous revenues to the endowment of chairs and to filling them with masters having an indisputable authority in science, and this little is badly employed. But they possess another in- stitution which appears called upon to render the greatest service to scientific studies, although hitherto it has done very little in this respect ; this is the institution of Fellowships. The stu- 52 NATURE [Afay 9, 1878 dents who have passed highest in the examinations are authorised to remain in the quality of Fellows in their college, where they are lodged and boarded; they receive, besides, a pension of 200/., which assures to them the liberty of devoting all their time to science. Oxford has 557 places of this kind, Cam- bridge 531. The Fellows may act as tutors to the students, but they are free not to use this privilege. They are not, moreover, obliged to live in the university town ; they may spend their pension where they please, and preserve it during an indefinite period. Save in exceptional cases, they only lose it when they marry, or when they accept some employment. They are the legal successors of the old student corporations, by and for whom the universities were founded and endowed. But beauti- ful as the plan of the institution may be, fabulous as may be the sums devoted to it, the services which it renders to science are of the most mediocre in the judgment of all unprejudiced Englishmen. This is probably owing to the fact that these young persons, although they are the Mte of the students, and find themselves in conditions exceptionally favourable to work, have not been, during the course of their studies, sufficiently profoundly penetrated by the vivifying spirit of science, to ex- perience that enthusiasm and that passion which impels men to make personal efforts. The English universities render, from certain points of view, very important services. They make their students cultured men, although little disposed to pass the political or religious limits of their party, and, in fact, they do not go beyond these ; the Tories dominate at Oxford, the Whigs at Cambridge. We ought, above all, to seek to rival them in two things. In the first place, they develop in a very high degree among their stu- dents, at the same time a lively sense of the beauties and the youthful freshness of antiquity, a taste for precision and elegance of language ; this is seen in the fashion in which the students manage their mother tongue. There is here, I fear, one of the weakest sides in the education of youth in Germany. In the second place, the English universities pay much more attention than om-s to the physical well-being of their students. These live and work in spacious, well-aired buildings, surrounded with lawns and with masses of trees ; their pleasures consist specially in games which, exciting a passionate emulation, favour the development of the vigour and dexterity of the body much more efficaciously than our military and gymnastic exercises. It must not be forgotten that if we deprive young people of the open air and of the opportunity of developing their vigour, they are all the more led to seek unhealthy distractions in the abuse of tobacco and strong drinks. We must admit, besides, that the English universities accustom their students to serious and energetic work, and make them preserve the habits of well- bred people. As to the pioral leffect of a rigid surveillance, it must be tolerably illusory. The Scotch universities, and some small English universities of recent formation, as University College and King's College, London, and Owens College, Manchester, approach more to 3ie German and Dutch type. The French universities have followed a different, almost absolutely opposite course. In consequence of the tendency of the French to upset, in virtue of logical theories, all which is the product of a historical development, their faculties have become simple establishments of instruction, special schools preparing for a career, and in which the programme of educa- tion is subjected to fixed rules. They are completely distinct from the institutions devoted to the progress of science, such as the ..College de France, the Jardin des Plantes, I'Ecole des Hautes Etudes. The faculties are absolutely separate from each other, even when they are placed in the same town. The course of study is determined with precision; numerous exami- nations serve to control the results. French education is limited to what is clearly and solidly established ; it gives an exposition of this, well ordered, carefully elaborated, easily intelligible, without entering upon doubtful questions and without going to the bottom of things. The masters charged with distributing it only need to have acquired much. Thus, in France, it is almost a mistake on the part of a young man possessing a talent full of promise, to consent to become professor in a provincial faculty. The French system is well suited to give to students of moderate capacity knowledge sufficient to follow the routine of their profession. They have not to choose between different professors, and, consequently, they swear in verba magisiri; there results a propensity to doubt nothing and to be self-satisfied. If the professor is good, that suffices for ordinary cases, where the student has only to imitate what he has seen his master do. It is only in extraordinary cases that it may be seen if he has really acquired penetration and judgment. For the rest, the French nation is well endowed, lively and ambitious ; this makes up for many of the faults of the system of education. In the French universities — and it is a characteristic feature of their organisation — the situation of a professor is absolutely independent of the assent of his pupils. The students belong- ing to the faculty in which he is professor are bound to follow his lessons ; the very high fees which are paid go to the treasury of the Minister of Public Instruction, and serve to cover the fixed salary of the body of professors ; the State contributes to the expenses of the universities only to a very small extent. If, then, the professor has not really the passion for education, and if he has not the ambition of attracting a large auditory, he may remain indifferent to the success of his instruction and take it easy. Outside the lecture-rooms, where they take their courses, French students live without being subjected to any surveillance, without esprit de corps, and without particular habits, confounded with young people of the same age who follow other careers. The development of the German universities has followed a course intermediate between these two opposite paths. They were too poor in private resources not to accept e^erly the help of the State in presence of the more and more costly demands of education. Consequently at the epoch when modern states tended to consolidation they were not in a position to defend their ancient privileges, and they had to submit to the direct- ing influence of the State. Consequently for all the important affairs of the universities, the supreme decision was, in prin- ciple, reserved by the State, and in times of political and religious disturbance an inconsiderate use was often made of this supremacy. In most cases, however, the universities were favourably treated by the governments newly arrived at inde- pendence. They required intelligent functionaries, and the glory of their university threw upon them a certain iclat. The administrative functionary came, for the most part, from the universities and remained attached to them. Thus, in the midst of the tumult of war and of political convulsions, in all these states struggling with the tottering empire and occupied in con- solidating their recent independence, while nearly all other special privileges disappeared, the German universities succeeded in retaining a much more considerable part of internal liberty (and indeed the most precious elements of this liberty) than was the case in conservative England and in that France which is feverishly chasing after liberty. Among us the old conception of the student remainsthe same ; he is always considered as a responsible young man who pursues science of his own accord, and who is free to regulate as he pleases the plan of his studies. If, for a small number of careers, it is still necessary to follow certain courses, this obligation is not imposed by the university as a university, but by the authority which will at a later period admit the candidate to follow these careers. Moreover, students have to-day, and had formerly, with few exceptions, full liberty to choose among all the universities of the German tongue, from Dorpat to Zurich, Vienna, and Graz. They may choose, besides, in each faculty, among the masters who teach the same subjects, without taking account of the distinction between ordinary professors, extraordinary pro- fessors, and privat-docenten. It is even allowable for them to obtain their instruction from books to any extent they may desire ; it is, in fact, very desirable that the works of the great men of the past should constitute an essential part of study. Outside the universities no surveillance is exercised over the conduct of the students, provided they do not come into collision with the agents of public security. Except in this case, the only control to which they are subject is that of their com- rades, which prevents them from doing anything against the honour of the body. The imiversities of the Middle Ages were close corporations, exercising over their members a jurisdiction which was extended to the right of life and death. As the students found themselves for the most part on foreign soil, this special jurisdiction was necessary, not only to \\ ithdraw them from the judgment of the authorities of the country, but also to be able to allay the conflicts which arose among themselves, and to maintain in the corporation sufficient good order and good breeding to insure the maintenance of the hospitality offered. Under the influence of the modern political organisation, this academic jurisdiction has gi-adually given way before the ordinary jurisdiction ; the last vestiges will soon disappear, but the necessity May 9, 1878] NATURE 53 always subsists in such numerous meetings of lively and eager youths, of submitting to certain restrictions calculated to pre- serve the tranquillity of their comrades and that of the citizens. It is to this necessity that, in cases of conflict, the disciplinarj jurisdiction of the University authorities responds. However, this end is still more surely attained by the sentiment of the honour of the body, and it is gratifying to have to acknowledge that this consciousness of their moral solidarity, and of the obligations of honour in the case of every one resulting therefrom, remains alive among German students. I do not mean by this to approve of all the special prescriptions of the code of honour of students. There are among the number certain remains of the middle ages of which it would be good to get rid, but this is a thing which can only be done by the students themselves. ( To be continued. ) STRIDULATING CRUSTACEANS A T the November meeting of the Entomological Society of ■*^ London, the president. Prof. Westwood, directed the atten- tion of the Society to a letter in Nature (vol. xvii. p. ii) from Mr. Saville Kent, on the above subject, hpropos of Mr. Wood- Mason's recent discovery of the existence of stridulating appa- ratus in scorpions. Mr. Wood-Mason remarked that structures in Crustacea, some of which certainly, and all of which probably, are for the pro- duction of sounds, were first brought to notice by Hilgendorf — in V. der Decken's "Reisen in Ost- Africa (Crustacea)" — but had been independently observed by himself in a number of species during his dredging excursion to the Andaman Islands in 1872. They were paired organs, as in scorpions, the Mygale, and the Pkasma to be brought to notice that night — that is to say, organs working perfectly independently of each other were on each side of the body. In some forms (I. ) they were seated partly on the body (carapace) and partly on a pair of appendages ; of these some {a) had the scraper on the body and the rasp on the appendages — e.g. Matuta, in which the organs are developed in both sexes ; and others (b) had the rasp on the body and the scraper on the appendages — eg. Macrophthalmus et affinia, in which the scraper was formed by a sharp-edged lamellar projec- tion on the meropodite of each of the chelipeds, and the rasp was the crenulated infraorbital margin ; in these the apparatus could only be developed in the males, the females having short and small and quite inconspicuous chelipeds, which hardly reached so far as to the margins of the orbits. In others (II. ) they were seated wholly on the appendages ; in the males of the species of Ocypode the rasp was on one and the scraper on another part of the same appendage ; in those of Pldtyonychus hipustulosus the rasps were on one and the scrapers on another pair of appendages ; the walking-legs of the second pair were here very long and robust, and their third joint (meropodite) had its upper margin produced upwards at apex into a sharp crest (the scraper) ; both Dana and Milne-Edwards had noticed the remarkable length and structure of this pair of legs, but the former alone had mentioned, in his description of the species, the regular transverse plication of the under surface of the pro- podite of the chelipeds, which constituted without doubt the rasp. The above did not pretend to be a complete account of stridulating apparatus in Crustacea ; but separated as he at present was from notes, drawings, and specimens, he could not go into greater detail. The cases of Macrophthalmus and of Platyonychus had not, he believed, been previously recorded. In the forms alluded to by Mr. Kent, no special sound -producing apparatus seemed to be developed. Everybody who had searched for animals on coral-reefs or had dredged in tropical seas was familiar with the " clicking " sounds emitted by ^zAlpheiixA their allies. The sounds which here always accompanied so sudden an opening of their claws to their fullest extent that dis- location seemed imminent each time, might be caused either by the impact of the dactylopodite upon the joint to which it is articulated, or by the forcible withdrawal of the huge stopper- like tooth of the dactylopodite from its pit in the immovable arm of the claw ; in which latter case the noises might be susceptible, mutatis mutandis, of the same physical explanation as that pro- duced by the withdrawal of a tightly-packed piston from a cylinder closed at one end. These were the explanations that occurred to him while watching a small species that lived in force amidst the branches of the zoophytes called Spongodes, the masses of which crackled all over when brought to the surface. The sounds in this case resembled very closely those made when sparks were taken by the knuckles from the prime-conductor of a small electrical machine. The sounds emitted by the Sphsero- miJ might possibly be produced by the impact of the terga of the posterior somites upon one another at the end of each move- ment of extension. Mr. Wood-Mason then announced the discovery of stridulating organs in Fhasmidce, in a species of Pterinoxylus, and in illustra- tion of his remarks exhibited an impression of Westwood's plate of Serville's species, P. difformipes. Here, as in'Crustacea and some other Arthropods, an apparatus working perfectly independently of its fellow was developed on each side of the body. The rough prominent basal portion of the costal nervure of the wings formed the rasp, in connection with which was developed a large oval "speculum," "talc-like spot," or "mirror." The rasps were scraped by the sharp and hard front edges of the tegmina, the dome-like form of which seemed admirably adapted, and pro- bably did, to some extent, serve to increase the sound by reson- ance. In Serville's species, according to Westwood's figure, the stridulating apparatus appeared to be more highly developed, the " mirror " being more distinct, and the tegminal cavities more spacious. The males of the Pterinoxyli were unknown. We had here another case in which functional stridulating organs are present in females. The only other insects known to him in which stridulating organs were seated partly on the wings and partly on the tegmina were the orthopterous (Edipoda, which, according to Scudder {Amer. Nat. ii. 113), stridulate during flight, in connection with which fact it was interesting to observe that the female Pterinoxyli, though incapable of flight, needed to expand their organs of flight in order to bring their similarly situated apparatus into play. UNIVERSITY AND EDUCATIONAL INTELLIGENCE Oxford. — At Queen's College, James Henry Hickens, Epsom College, has been elected to a Natural Science Scholarship. Cambridge. — The Rede Lecture will be delivered by Prof, Clerk-Maxwell, in the Senate House, on Friday, May 24, at half- past 2 o'clock, on the Telephone. Owens College. — Should this institution ever be trans- formed into the University of Manchester, it will only be after overcoming a good deal of strong opposition. The Liverpool Town Council are to petition in favour of a new corporation with power to incorporate Owens College and other institutions, and that the new University do not bear any merely local or personal appellation. Naturally, also, the Yorkshire College does not look kindly on the proposal, although until Owens College resolved to take this step the two institutions were on very friendly terms. We tnist some arrangement will be come to ultimately that will satisfy all concerned. Working Men's College. — The Science Classes at the Working Men's College, which, during the last three years have, under Mr. Dunman's teaching, have become so popular and useful a feature of that institution, assembled on Saturday, last at the Broad Street Restaurant to celebrate -the termination of a very successful course by a dinner. Mr. Thomas Hughes had pro- mised to be present, but in his compulsory absence Mr. Dunman himself occupied the chair. A pleasing feature of the evening was the presentation to Mr. Dunman, by the students in these classes, of a handsome despatch box as a token of their apprecia- tion of the thoroughly eflicient manner in which he has dis- charged the duties of science teacher. Strassburg. — The Extraordinary Professorship of Petro- graphy, lately occupied by Prof. Rosenbusch, is to be filled by Dr. Cohen, of Heidelberg. SCIENTIFIC SERIALS The Journal of the Russian Chemical and Physical Societies of St. Petersburg (vol. x. No. 3) contains the following papers : — On the mono- and dioxymalonic acids (Part 2), by R. Petrieff". — Researches on the transformation of diethylcarbinol into methyl- propylcarbinol, and on the synthesis and the properties of diethylacetic and methylpropylacetic acids, by A. Saytzeff. — On the synthesis of diphenylenephenylmethane and of dipheny- lenetolylmethane, by V. Hemilian. — On the falsification of butter, by P. Koulechoff. — On the elementary law governing the reci- procal actions between currents and magnets, by A. Socoloff". 54 NATURE [May 9, 1878 Verhandlungen der k.k. Zoologische botanischen Geselhchaft in U'ien. {1867, vol. ii,) This volume, like its predecessors, con- tains valuable additions to zoological and botanical literature. By far the most important papers contained in it are Dr. L. Koch's notes on Japanese Arachnida and Myriapoda, and Herr H. B. Moschler's remarks on the Lepidoptera fauna of Surinam, continued from a former volume. Of other interesting papers we note :—Lichenological excursions in the Tyrol, by F. Arnold. — On the spiders of Uruguay and other parts of America, by E. ; Keyserling. — Introduction to the monography of Phanero- pterida, by Brunner von Wattenwyl. — Hymenopterological notes, by F. F. Kohl. — On the flora of the Ionian Islands of Corfu, Cepbalonia and Ithaca, by G. C. Spreitzenhofer. — On a species of Aphis, Pemphigus Zeae Mdidis, L. Duf, which attacks Indian corn, by Dr. Franz Low. — Notes on the Aeolidiadae, by Dr. Rudolph Bergh. — On the Brazilian ants collected by Prof. Trail, by Dr. Gustav Mayr. — There are also in this volume some smaller communications from the botanical laboratory of Dr. H. W. Reichardt. SOCIETIES AND ACADEMIES London Royal Society, April ii. — "On Stresses in Rarefied Gases arising from Inequalities of Temperature," by J. Clerk- Maxwell, F.R.S., Professor of Experimental Physics in the "University of Cambridge. 1. In this paper I have followed the method given in my paper "On the Dynamical Theory of Gases" (Phil. Trans. 1867, p. 49). I have shown that when inequalities of tempera- ture exist in a gas, the pressiu-e at a given point is not the same in all directions, and that the difference between the maximum and the minimum pressure at a point may be of considerable magnitude when the density of the gas is small enough, and when (the inequalities of temperature are produced by small solid bodies at a higher or lower temperature than the vessel » The meanings of the two expressions are identical, and the comparative simplicity of the second is due solely to the fact that it takes space of three dimensions as it finds it ; and does not introduce the cumbrous artificiality of the Cartesian coordinates in questions such as this where we can do much better without them. In most cases at all analogous to those we have just brought forward. Prof. Clifford avails himself fully of the simplification afforded by quaternions. It is to be re- gretted, therefore, that in somewhat higher cases, where even greater simplification is attainable by the help of quaternions, he has reproduced the old and cumbrous notations. Having gone so far, why not adopt the whole ? Perhaps the most valuable (so far at least as physics is concerned) of all the quaternion novelties of notation is the symbol dx dy d 2 whose square is the negative of Laplace's operator : i.e. A glance at it is sufficient to show of what extraordinary value it cannot fail to be in the theories of Heat, Electri- city, and Fluid Motion. Yet, though Prof. Clifford discusses Vortex-Motion, the Equation of Continuity, &c. we have not observed in his book a single V- There seems to be a strange want of consistency here, incoming back to such "beggarly elements" as instead of - Sva, especially when, throughout the investigation, we have ead before the Royal Saciety on the Life-History of a Minute Septic Organism : with an Account of Experiments made to determine its Thermal Death Point. By the Rev. W. H. Dallinger, F.R.M.S. ' M. M. J., vol. xi. pp. 97 — 99. May 23, 1878] NATURE 103 observations on the frequency of the recurrence of the process of fission, by the continual following of one seg- mental product of the act ; and also from its beginning to its cessation, in a series of separate organisms, making manifest the periods of greatest fissional intensity ; and also showing the result following on the cessation of fission. In the majority of cases it was an exhaustion of vital action and death : but in a certain proportion, in which fission was not so long continued, it was a rapid change to an amoeboid condition, resulting in the absorption or fusing of the lateral flagella with the body, and a change of form ; the organism becoming now quite oval and having only an anterior flagellum. It swims easily, but has lost all the power and freedom of motion pos- sessed before, moving only in a straight line. But it soon comes into contact with a colony of the organism in the springing condition, attaches itself to one of them, which then soon unanchors and both swim away. In the course of time their movements become sluggish ; the sarcode of the bodies is palpably blending, they become quite still, except for amoeboid movements, and then become one mass, oval in form, which elongates into a spindle-shape, remaining motionless and still in all respects for three or four hours ; when, as was ultimately, and by long continued effort made out, it pours out ex- quisitely minute, opaque, apparently round specks, which, when carefully and steadily followed with the best appliances, were seen to develop into the adult form and size. The author then desired to discover the relative heat- resisting power of the perfect form, and the germ or spore. The adult forms were proved by a very direct method, which was fully detailed, to be wholly destroyed at a temperature of 142° F. Two methods of heating were employed to test the resistance of the spore. One was the " dry " method which had been employed in the former researches ; but which was somewhat modified and used with special precautions ; and the result of an elaborate series of experiments proved, that by this mode of heating, the spore could resist a temperature of 250° F, It was next determined to test the heat resistance of the spore when they suffered the heat, diffused in a fluid. The difficulty of accomplishing this, so as to secure an unmistakable result was carefully pointed out and dwelt on ; and the opinion recently expressed by Dr. Bastian that it was " perfectly easy" shown to be an error. The apparatus employed for the purpose was specially delicate, but enabled the author to test directly the results of heat on the spores as well as on the adult organism, without exposure after the vessel was once sealed . The form used was specially devised for these observations. The temperatures up to the boiling point of water were got in melted paraffin, and higher temperatures in a digester. The result was that 220° F. was found to be the limit of temperature which the spore of this organism could endure without destruction of vitality. That is to say 30° F. lower than the same spores could bear in a " dry " heat. But it was pointed out, that to endure this temperature, implied protection of some kind : but that this in the nndeveloping germ, was not only capable of being understood, but would doubtless prove of immense value to the organism. OUR ASTRONOMICAL COLUMN The University Observatory, Oxford. — Prof. Pritchard has published No. i of Astrono7nical Observa- tions made at the University Observatory, Oxford. It comprises observations made between the autumn of 1875, when the establishment was first organised, and the end of 1877. They relate to the satellites of Saturn, double stars, and the five comets discovered in 1877, by Borrelly, Winnecke, Swift, Coggia, and Tempel, for which provisional elements and, in the case of Winnecke' s comet, an extensive ephemeris are added ; also elements of the orbits of | Ursae Majoris, 70 Ophiuchi, and ^ Bootis, and comparison of the same with the interpola- tion curve drawn according to the method of Sir J. Herschel. The observations of the satellites of Saturn consist of differences of R.A. and N.P.D. from the centre, of the primary, facilitated by the ephemerides which Mr. Marth has regularly supplied; together with the other observations now printed, they have been made with the refractor of I2j-inches aperture, constructed for the observatory by Mr. Howard Grubb, of Dublin, Mr. W. E. Plummer, the first assistant, being credited with the greater part of them. In addition to the above work, it is mentioned that nearly twelve hundred measur- able photographs have been secured by means of Dr. De la Rue's reflector, which he presented to the Obser- vatory, and which is mounted in the eastern dome, and a very beautiful instrument for completing the measure- ment of these photographs has been recently received through the liberality of the same gentleman. The in- stitution is under the control of a Board of Visitors, as usual in so many of the more important astronomical establishments at the present day, the Board being com- posed of the Vice-Chancellor, the Proctors, the Astrono- mer-Royal, the Director of the Cambridge Observatory, the Radcliffe Observer, and four other members elected by the Convocation of the University; these members are at present. Dr. De la Rue, Prof. Bartholomew Price, J. A. Dale, M.A.,''and W. Esson, M.A. The position of the University Observatory is in lati- titude 51° 4S' 34"'i5, and longitude 5m. o'4os. west of Greenwich. The Cincinnati Observatory. — No. 4 of the pub- lications of this observatory, just issued, contains the results of measures of double stars made in the year 1877, with the ii-inch refractor, the object-glass of which was replaced early in the year after having been-, successfully refig^red by Alvan Clark and Sons ; in< addition to this improvement a new driving clock was added. The stars measured are, with very few excep- tions, situate between the equator and 40° of south de- clination, and this selection of objects gives a rather special value to the Cincinnati observations, though it has been notified from Melbourne that the remeasure- ment of Sir John Herschel' s southern stars is in progress there. The methods of observing at Cincinnati, and the investigation of personal equation, are explained in the- introduction, and the larger differences in the measured angles and distances, found on comparison with the catalogues of Struve, Sir John Herschel, Jacob (Poona), and Dembowski's measures of doubles discovered by Mr. Burnham, are indicated. Some of these larger differences occur in the case of well-known rapidly- moving binaries ; but there are others which deserve further attention, to decide upon the cause of the. observed changes. The following may be mentioned : — Star. k 2036 Lalande...24i6 h 3447 Lacaille ...462 h 3461 c Sculptoris ... Sir J. Hkrschel's Measures. Pos. DIst. 1836-54... 40°4 — 36-96... — I -82 1837-11... 75-5 — 37'5i-- — 3'i2 1836-54... 69-6 — 36-70... — S'53 Cincinnati Measures. Pos. Dist. 1877-76... 25-1 1-40- 1877-80... 90-1 2-20- i877"85- 59'o 4-84- Of stars observed by Sir J. Herschel with the 20-feet reflector, for Nos. 2,904, 3>494> and 5,113 (which are re- spectively Lacaille 8,262, 702, and 8,098), the Cincinnati measures show differences greater than 20°. The posi- tions of these stars for 1880 are : — 104 NATURE \_May 23, 1878 Right Ascension. S. Declination, h. ra. s. , / h 2036 I 14 4 16 26 » 3447 I 30 35 .30 31 » 3461 I 40 I 25 39 ,. 3494 2 14 46 35 59 » 5"3 19 17 30 29 32 M 2904 19 47 7 24 14 The "mean results" at the end of this publication apply to upwards of 500 objects. tf?j,THE Reappearance of Encke's Comet.— Dr. von Asten,, in an extract from the Bulletin of the St. Peters- burg Academy, has circulated an ephemeris of Encke's comet for the return in the present year, and it is also printed in No. 2,197 of the Astroitoviische Nachrichten. The elements have been perturbed to April 24, 1878, taking into account the attraction of the six old planets and the effect of a resisting medium. The perihelion passage takes place July 26 • 1 1 59, G. M.T., and Dr. von Asten especially insists upon the importance of observations in the southern hemisphere after perihelion, for the improve- ment of the theory, and urges that at least two complete series of observations with moderately powerful instru- ments should be obtained, for reasons which he states are explained in a memoir now in the press. The following positions are interpolated from his ephemeris for Berlin noon, corresponding to 8h. 46m. mean time at Mel- bourne : — Right Ascension. N^f^f^^olar L c>g. D istaj^ce h. m. s. , / August I ... 9 46 o ... 79 19*8 ... o'o824 5 ... 10 17 23 ... 83 538 ... 0-0597 ,, 9 ... 10 47 39 ... 88 28-0 ... 0*0399 ,, 13 ... II 17 24 ... 92 58-0 ... 00248 ,, 17 ... II 47 o ... 97 i8-8 ... o'oi55 ,, 21 ... 12 16 30 ... lOI 24*3 ... 0"OI23 „ 25 ... 12 45 47 ... 105 87 ... 0-0151 „ 29 ... 13 14 34 ... 108 27-3 ... 0-0233 Sept. 2 ... 13 42 30 ... HI 17-4 ... 0-0359 The elements of the orbit for April 24, 1878, are: longitude of perihelion, 158° 19 41", ascending-node, 334° 39' 10" (M. Eq. 1878-0), inclination, 13° 6' 40", eccentricity, 0-8491669, semi-axis major, 2-2ioi59i. The perihelion distance is 0-33344, the aphelion distance, 4-08794, and the semi-minor-axis, 1-16752. The sidereal period at the above date is 1200-8 days. NOTES The funeral of the late Prof. Henry, at Washington, was an imposing pageant, being attended by the President and the members of the Cabinet and the Congress — the latter body adjourning from respect to his memory — with a large number of prominent men from all parts of the country. Prof. Spencer F. Baird succeeds Prof. Henry as secretary to the Smithsonian Institution. A MONUMENT to the late eminent physicist, Dr. Robert von Mayer, -will be erected at Heilbronn, in Wurtemberg. Herr Gustav Rumelin, the Chancellor of Tubingen University and well-known critic of Shakespeare, will shortly publish a biography of Dr. von Mayer. Prof. Helmholtz has nvritten to the Royal Institution to obtain a_bust of Faraday, and to the French Academy of Sciences for busts of Ampere and Regnault. No bust of Regnault being in existence, one will be executed at the expense of the Govern- ment, by M. Noel, and placed in the Hall where the Academy meets. A cast will be sent to Berlin as requested. The honorary membership of the Geographical Society of Italy, at Rome, has recently been conferred on Dr. George Bennett, of Sydney,^ who is well known as a naturalist and traveller, and who it seems had been exceedingly active in the furthering; of Signor L. 'M. d'Albertis' late expedition to New Guinea. Prof. Ernst Haeckel has been nominated honorary mem- ber of the Geographical Society of Lisbon and of the Micro- scopical Society of San Francisco. The system of science and art education which centres at South Kensington and branches to the remotest parts of the kingdom, has years ago assumed the dimensions of a national organisation and done more, probably, than any other means, to foster a wide-spread artistic taste and a desire for scientific knowledge among the people. The well- trained teachers of the department are everywhere doing their humanising and elevating work. This immense organisation, every one now admits, is mainly due to the energy, intelligence, and foresight of one man, Sir Henry Cole, who has happily survived .much that would have daunted a less enthusiastic and public-spirited man — survived to receive, as he did last Thursday, a well-earned and appropriate honour. On that day a large number of ladies and gentle- men assembled at Grosvenor House, by the permission of the Duke of Westminster, for the purpose of presenting to Sir Henry Cole a testimonial, the result of an effort originated some years ago. The memorial was in the form of a marble bust and memorial tablet in della robbia ware, containing a portrait of Sir Henry in mosaic. The total amount of sub- scriptions was 2,924/. 1 3 J. i^d. After paying expenses for the monument, portrait,^ and bust. Sir H, Cole had already received z,oix>l. The Duke of Westminster, in present- ing the testimonial, bore testimony to the advantages which Sir Henry Cole had conferred upon the nation in his efforts to promote the development of science and art. Sir Henry Cole, in acknowledgment, said his words could but feebly express his hearty thanks to the princes, jieers, com- moners, men of science, art, and literature, industrial producers and handworkers, who had joined in this testimonial. After fifty years of public life, with his health declining from the constant strain of official work, he (Sir H, Cole) felt it right to resign his duties. He was not idle in his leisure. His health had improved, and he hoped still to do some useful public work. He was trying to obtain a national recognition for music, the first and most popular of all fine arts, to help elementary education to become the work of the people rather than of the State," and to promote improved health through, out the country. The portrait in mosaic of Sir Henry is to be offered to the South Kensington Museum. The marble bust will be presented to his Royal Highness the Prince of Wales, as pre- sident of the Albert Hall, with a request that it should have a suitable place in the Hall. A strange jubilee is proposed to be celebrated in Italy during 1879. bur readers know that next year 1,800 years will have elapsed since the two cities of Pompeii and Herculaneum wera destroyed by earthquakes and eruptions from Mount Vesuvius. It is now intended to celebrate the anniversary of that year of destruction, and the site of the celebration is to be at Pompeii itself, as being the better known of the two buried cities. In the April number of the Bulletin of the Imperial Academy of St. Petersburg it is stated that a clergyman named Pervou- chine has proved that the number 2"" -f- i is divisible by 7-2^* -V I. Bouniakowsky has verified the result at the request of the Academy. Hitherto the only exception known to Fermat's statement, that all numbers of the form 2* -f I are primes, is that of m = S where Euler showed that 641 is a divisor, M, C. Th. Liebe {Proc. Imper. Geol. Instit., Vienna, March 5, 1878) has found a considerable quantity of remains of the Marmot in the Diluvium near Gera (Thuringia), indicating May 23, 1878J NATURE 105 ihe existence of a larger form than the existing species, and intermediate in character to the European marmot and the bobak, and he .regards it as representing the primordial stock from which the living species have proceeded in the coarse of time. The region in which these remains have been found bears a steppe character, the fauna and flora of steppes being met with both in mountainous regions and on plains. M. Liebe, who is a votary of Baron Richthofen's sub-aerial theory, admits the diluvial district of Germany to have been once a steppe region with an extreme climate and analogous to the present steppes of the Altai. The French Ministry for Public Instruction has completed in the Central Palace of the Exhibition the installation of the *' Salle des Missions Scientifiques." A large map has been exhibited on which all the names of the scientific missionaries are inserted on the couniries which they have explored on behalf of the French Government. The collection of works published by the living members of the " Corps Enseignant" (French University) is ready; it is composed of more than 4,000 volumes neatly bound. This library is open every day from 8 to 10 in the morning. Admission to the palace is obtained at this early hour by a double ticket] (price 9 francs). Not a single gallery in the Trocadero Palace has been yet opened. The success of the Exhibition is increasing daily. The average number of admissions on payment has been more than 40,000 a day for the first fourteen days. The sale of tickets by the agents is more than 1,200,000. The number of season-ticket holders was 1,000 in the beginning of .last week, although no real advantage is offered to them. The system of conveyance by trams, railways, and steamers is excellent, and working very well. M. Bardoux has proposed a credit of 100,000 francs for the purpose of sending to Paris a number of instituteurs who will take part in their special congress during the Exhibition. The Proceedings of the Literary and Philosophical Society of Liverpool for 1876-77 forms, as usual, a thick volume, containing several papers well worthy of careful reading. The paper of chief scientific interest in this volume is that of Mr. A. J, Mott on Haeckel's " History of Creation," which, with the elaborate discussion that followed, is likely to interest all who are in- teresed in the subject. A FIRM at Melbourne, New South Wales, claims to have im- proved the Abyssinian tube-well by attaching a drill to the first tube, and cutting through rock by imparting a rotary motion to it, instead of merely hammering it tlnrough as heretofore, which plan has b-jen found not to succeed in hard soils. In confirmation of our remarks on the recent progress science- wards in Spain, we may state that we have received further papers. One a pamphlet of thirteen pages is a paper entitled El Alcoran, by Seiior D. Eduardo Saavedra, read at the eighth conferencia (February 25th, 1878) of the Institucion libre de ensenanza. The other is the prospectus of the Revista General de Legislacion y Jiirispriidencia, publicada por D, Jose Reus y Garcia con la coloboracion de distinguidos Jurisconsultos y publicistas (now in the twentieth year of its publication). From a Japan contemporary we learn that copper-smelting works are being built by Japanese near Kobe. The ore to be used will come from a mine near Ikeda, and is said to contain a considerable quantity of silver which is to be extracted first. Coal and copper appear to have been recently discovered in several places in this part of Japan. A BRILLIANT meteor was seen at Geneva at 9.45 p.m. on Sunday week. It moved very rapidly from east to west,, was in the shape of a pear, and was of a greenish hue, leaving behind it a slight train of light. This was evidently the same meteor that was seen by our correspondents referred to in last week's Nature; the; time was the same, making allowance for the difference of iongjltude. between Geneva and this country. '-The total produetioa of silk cocoons in Europe amounted upon an- average to 58,000 tons per year during the last five years. Italy stands first in the list of silk-producing countries ; it produces 39,000 tons per year. France produces about 10,000 tons, Turkey 4,000, Spain 2,200, Austria 1,900, Portugal 250, . Greece 200, Russia 150, Germany 100, and Belgium and Switzerland only 100 tons together. The King of Italy has conferred the Cross of the Order of SS. Maurice and Lazarus upon Prof. Monmisen, of Berlin. The well-known geologist and academician, Gregor von Hel- mersen, of St. Petersburg, celebrated the fiftieth anniversary of his entering the Russian army, on the 5th instant. It is telegraphed from New York, May 14, that a despatch from Havannah announces that a terrific earthquake has occurred at Cua, in Venezuela, 600 persons having been killed- A heavy shock was also felt at Caracas. An earthquake is reported from Gottingen. On May 6 two shocks were felt, one at 10,34 the other at 10.37 p.m. The former was of greater force than the latter, and their duration was three and two seconds respectively. An earthquake was also felt in a large number of places in Morbihan (Britanny), on the ii4th instant, in the morning ; the hours vary according to the places. At Hennebout, a small seaport on the Blavet, it occurred at 7h. 3m., duration six seconds ; at Vannes, 5h. 40m. local time (6h. 20m. Paris time). The direction was from west to east. Commotions were also felt in Lorient and Port Louis almost at the same hour as at Vannes. We have already referred to the American Journal of Mathematics promised us from the Johns Hopkins University, and were able to mention the names of some of the contributors, all of them of the first rank. We have not yet received the first number, but from a note in the Nation we see it has ap- peared, and that the programme will delight our mathematical friends. The first number contains, in 104 handsomely-printed quarto pages, eight articles, two of them from foreign con- tributors, in which the separate departments of astronomy, mechanics, physics, and pure mathematics are all represented. The first article is a short note of three pages, containing the proof of the proposition, that " if a fourth dimension were added to space, a closed material surface (or shell) could be turned inside out by simple flexiu-e, without either stretching or tearing." This is followed by the first part of a paper upon the lunar theory, by Mr. G. W. HiU. Prof. Eddy, of Cincinnati, presents a simplified equation to express the rela- tionship between the moments of flexure of a straight elastic girder at three successive points of support. An algebraic solu- tion of the so-called irreducible case in cubic equations, with examples, covers eighteen pages. A short note on the theory of gi-oups is communicated by Prof. Cayley, of Cambridge. Prof. Rowland's paper is a contribution to our know- ledge of the theory of electric absorption. A very favourable review of Ferrero's treatise on the method of least squares is given by Mr. C. S. Peirce, and the balance of the number is occupied by Prof. Sylvester with a paper in which the new atomic theory of chemistry is applied to the graphical repre- sentation of certain mathematical conceptions. A paper on this subject, by Prof. Sylvester, has already appeared in NATURE. We notice the appearance of the concluding part of the Jahresbcricht der CJumie for 1876. This almost indispensable companion of the chemist, founded by Liebig and Kopp, is now under the editorship of Prof. Fittica, of Marburg, assisted by a xorps of twelve other leading German and Austrian chemists, and has reached its twenty-ninth volume. A glance at the space allotted to the various sub-divisions gives a general idea of the io6 NATURE [May 23, 187S tendencies of modern chemical research. General and physical chemistry occupy 160 pages, inorganic chemistry 140, organic chemistry 650, analytical chemistry 100, technical chemistry 170, chemical geology 40, and mineralogy 60. Over 1,000 authors are referred to in the course of the work. It is a strange circum- stance that German should be the almost exclusive medium for the publication of exhaustive and elaborate annual reports of the progress made in each branch of natural science. Prof. Kolbe, of Leipzig, has just added another to the numerous German text-books of inorganic chemistry, and justi* fies its appearance by the opinion that the existing works, with the exception of the translation of Roscoe's Chemistry, contain far too much material for elementary treatises. A vigorous war- fare is waged against the now so prevalent use of Latin and Greek names among German chemists, a custom certainly from a foreign standpoint not to be regretted, bringing as it does the scientific nomenclature more in unison with that of England, France, and Italy. We notice also that Prof. V. Richter, of Breslau, has just issued a second edition of his Text-book of In(M:ganic Chemistry, and that Prof. Wislicenus is engaged on a new and modernised edition of Reg- nauli's Chemistry, the ninth edition of this classical little work which has appeared in Germany. A SECOND edition of Prof. Klenke's well-known work on the adulteration of food is now being published at Leipzig (Weber). The author has chosen the dictionary form for this edition, and the title is now " lUustrirtes Lexikon der Verfiilschungen der Nahrungsmittel und Getranke." The last part published of the Silzungsberichle der Miinchener Academie fur 1877 contains an interesting report by Herr Her- mann Schlagintweit-Sakiinliinski upon the ethnographical ma- terial in the large collections made by the brothers Schlagintweit on their celebrated travels, and gives a detailed account of its distribution at the royal " Burg " at Niirnberg. The publication of the eighth edition of Ed. v. Hartmann's " Philosophie des Unbewussten " is now announced. It is a long time since a purely philosophical work has run through eight editions. The experiment of using superheated water for locomotives has been successfully tried on the tramway connecting Reveil and Marly-le-Roi, in France. The engines are chained with water heated to 180° C, which is allowed to vaporize as fast as required ; and by doing away entirely with furnaces in the locomotives, the dangers of explosion, as well as the causes of terror to passing horses, are easily avoided. A locomotive, propelled in this manner, and attached to two carriages, ascen- ded a gradient of 5^ in the hundred at the rate of sixteen miles an hour. M. L. A. FoRSMANN shows, in a recent communication to the Swedish Academy, that solenoids are able to produce the same unipolar induction currents as magnets, and that the same laws rule in both cases. An immense deposit of guano has recently been discovered in the Wershchowskij grotto near Oizowo, in the Russian govern- ment of Kjelze. Chemical analysis proved the quality of the guano to be in no way. inferior to that of Peru. It is stated that Prussian agriculturists have already sent agents to Oizowo to purchase large quantities of this guano. In the April session of the Deutsche geologische Gesellschaft Prof. Beyrich exhibited two specimens of Ammonites iphicerus, one of which came from Lichtenfels, in Bavaria, and the other from Mombassa, in South Africa. On account of their close similarity he assigned to the Jura formations of Mombassa the same age as that of the Bavarian deposits. The specimens attracted especial interest on account of the complete preserva- tion in both cases of the aptychus, the origin and use of whicli still remain an unsolved problem. Herr Romer presented a specimen of Archjeocyathus from the strata in the Sierra Nevada immediately above the archaic deposits. It is the first fossiP found in these formations, and places them probably in the olcf Silurian. Papers were likewise presented by Herr Ladebeck oir the regularity in the deformation of markasite crystals, and by Herr K. Lossen on the albite gneiss of Schweppenhausen. Some experiments have lately been made by M. Grehant with, regard to endosmose of gases through lungs separated from an. animal. He finds in the phenomenon two distinct phases ; in the first, the lungs swell till they even touch the walls of the bell- jar in which they are contained, while a manomoter shows there is considerable increase of pressure. Then comes a second phase, in which the lung returns to its original volume and the pressure diminishes. From observations on the living animali, however, M. Grehant concludes that in this case the phenomenon is very flight indeed. Prof. Kirchhoff has presented to the Berlin Academy a series of considerations on the movement of the electric current in submarine cables, based on Helmholtz's Avell-known equationa for the components of the intensity of a current, and tha electrostatic moment dependent on the capacity for dielectric polarisation. The conclusions deduced are, that the rapidity of propagation of the electric waves increases with the conductivity of the gutta-percha covering, while the breadth of the undula^- tions decreases in the same ratio. A GERMAN translation of Father Secchi's work, " On the Astronomy of the Fixed Stars," will shortly be published by F.. A. BrockhauR, of Leipzig. It will form the thirty-fourth volume of the International Scientific Library. In No. 8 of the Jjurnal oiiht Russian Chemical Society are two papers, by M. Lermontoff, on t he employment of two galvanometers provided each with a Topler's apparatus for reducing the oscil- lations of a magnet, and on the methods employed by M. Brauer for the construction and verification of balances of prec'sion* This latter paper is a detailed description of the methods devised by the skilful optician of the Pulkova Observatory for manufac» turing and adjusting the prisms of balances, special apparatus having been devised by him and constructed for these purposes. The verifying apparatus discovers any deviation from the straight line on which the prisms should be placed, if it exceeds 30", and the equality of the length of the arms of the balance is verified with a precision of 0*0000125 of their length. We are all the more pleased to see the appearance of ;uch a description, as the methods used by constructors of precise scientific apparatus ar2 generally unknown. We notice also in the same number a note, by M. Borgmann, on Maxwell's theory on the tensions in the magnetic field; and a note, by M. Geschus, on the various theories proposed for explaining the radiometer. A. Arzrxjni communicates, in arecentt number of Groth's Zeiischrift Jiir Crystallographie, a number of interesting results from a study of the crystalline properties of various organic bodies. Triphenyl-benzene is found to possess the property of double refraction in a degree surpassing that of any other crys- talline body yet known. In substituted compounds he shows also that the introduction of the nitro-group invariably causes a much slighter change in crystallographic properties than when hydrogen is substituted by bromine or iodine. The Phylloxera, which has been in Spain and Portugal for some time, is now reported to have got as far as Greece. The additions to the Zoological Society's Gardens during th* past week include a Syrian Fennec Fox (^Cams fcmelicus) froia May 23, 1878] NATURE 107 Arabia, presented by Commander F. Catton ; a Wood Owl {Syrnium aluco), European, presented by Mr. C. B, Wharton ; a Copper Head Snake {Ctnchris contortrix) from North Ame- rica, presented by Dr, Painter; a European Bearded Vulture {jGypaetus barbatus). South European, a Rattlesnake (Crotalus durissus) from North America, deposited ; a Collared Fruit Bat (Cynonyderis collaru), a Reindeer {Ran^ifer tarandus), a Chinchilla {Chinchilla lanigera), born in the Gardens. RECENT RESEARCHES ON THE PHENOMENA OF FLUORESCENCE COME time ago Herr E. Lommel drew attention to the fact that ^ certain substances do not follow the rule mentioned by Prof. Stokes, viz., that each ray of light produces fluorescent rays of smaller refrangibility only ; recently Herr Lommel found several other substances which partly follow and partly deviate from Stokes's rule, which is thus proved to be of somewhat limited ralidity. Herr Lommel communicated his further researches on this subject at a recent meeting of the Physical Society of Erlangen. He now divides all fluorescent bodies into three classes : the first class comprises those substances upon which each homogeneous ray of light, capable of producing fluorescence, produces the whole fluorescent spectrum (fluorescence of the first order) ; the second cla -s contains those substances upon which the same ray of light produces only those rays of the fluorescent si3ectrum which are of a smaller (or at most of an equal) refrangi- bility than the ray itself (fluorescence of the second order). The third class finally, embraces those bodies whose fluorescent spectrum consists of two parts, one of which corresponds to fluorescence of the first, and the other to fluorescence of the second order (compound fluorescence). Herr Lommel enume- rates nine substances of class I., twenty-five of class H., and seven of class III., and gives the commencement of their fluorescence in the spectrum and the extent of the latterin tables accompanying his paper. If we examine the scPies of substances enumerated by Herr Lommel, we find no less than fifteen different ones, which deviate from Stokes's rule, i.e., depart from it altogether (the nine substances of class I.) or only in part (the first six substances of class III.). Of course the substances in class II. which follow this rule are more numerous. Investigating the peculiarities of these three classes more closely, and in various directions, we arrive at the following conclusions : — I. The first class comprises substances with very'strong bands of absorption only, of which one remains visible even when the solution is greatly diluted and after the absorption in other parts of the spectrum has become imperceptible. Accordingly these substances are strongly and intensely coloured (green, red, orange, yellow). The absolute maximum of fluore.xence corresponds to this absolute maxxmum of absorption in the fluorescence-spectrum. 2. The second class embraces all fluorescent substances which show only a one-sided absorption of the more refrangible end of tie spectrum. They therefore appear yellow, brown, or colour- less, the latter principally if the absorption bands lie only in the extreme violet and ultraviolet. To this class certain bodies belong. which 'show absorption bands to which maxima of fluorescence correspond at the same time. But these absorption bands appear broad and indistinct (so-called shadows) and they are not really maxima. If the solution is diluted they disappear very soon, and long before the absorption in the violet ceases to be perceptible. Nitrate of uranium shows a number of strongly marked absorption bands, which, however, are in nowise related to fluorescence. Uranium glass as well, which belongs to the first class, shows absorption bands in the red and yellow which have nothing to do with its fluorescence. The green colour of the fluor spar from Alston Moor is caused by an absorption band in the red, and this also has no reference to fluorescence. 3. The third class, like the first, contains only bodies with strong absorption bands and of intense coloration (green, blue, violet, red, orange). Fluorescence of the first order therefore seems to be in causal connection with the existence of a prominent maximum of absorption and fluorescence. 4. The fluorescent spectrum of the substances in class I. is of •equal colour everywhere, if we neglect the slight changes in the shades of colour, which are caused by the absorption exercised by the substance upon its own fluorescent light. At the parts which are less fluorescent, a proportionate diminution of the fluorescent rays most subject to absorption takes place, and hence a deepening of the shade ; these rays are at the same time the more refrangible ones in all bodies belonging to this class. 5. The fluorescent spectrum of the substances in class 11. is of unequal colour, changing gradually its tone of coloiu", and it only becomes equal where the spectrum of the fluorescent light ends. But even here the fluorescent spectrum may seem of equal colour everywhere to the naked eye. This is the case where the spectra of the exciting and the excited rays are super- posed on one another only a little (morine-alumina solution ; nitrate of uranium), or if the fluorescence begins in the blue or in the violet. 6. The fluorescent spectrum of the bodies in class III. con- sists of two parts, viz., one equally coloured in its whole length (less refrangible), and one coloured differently, with gradual change of colour (more refrangible), becoming equally coloured only where the total spectrum of the fluorescent lights ends. At the boundary of the two parts an almost sudden change of colour takes place. 7. The substances of class III. behave like mixtures of a substance of class I. and one of class II. The solutions of orchil and litmus appear as mixtures of two fluorescent substances, from the fact that, according to the dissolving medium, now one and now the other fluorescence is prominent, and the aspect of the total fluorescence changed. From two different kinds of litmus Herr Lommel obtained alcoholic extracts, of which the one showed orange and the other greenish-yellow fluorescence in daylight ; their fluor- escent spectra, however, showed no difference, except that the yellowish-green part was proportionately more developed in the second specimen. Fluoride of aniline may also be considered as a mixture of two fluorescent substances. That brasileine is a mixture of this kind is rendered very probable by the circum- stance that the fluorescence of the second order is destroyed by the addition of soda, but strengthened by the addition of ammo- nia, while that of the first order remains intact. Whether the chamaeleine colouring matters are really chemical compounds, as they certainly appear to be, must first be decided by a closer investigation of these substances. If it could be proved beyond doubt that all these substances are mixtures of two fluorescent substance?, we might abolish class III. altogether, and enumerate the separated substances in classes I. and II. But, since this separation has not yet been actually effected, and since the possibility, that a unit {einheit- lich) molecule may possess both kinds of fluorescence simulta- neously, cannot be discarded h priori, Herr Lommel felt compelled still to retain class III., i.e., bodies possessing com- pound fluorescence. By artificially mixing substances of the first and second class, fluorescences of the third order may be obtained in great variety. In this way wonderful effects of colour are often obtained, and they may be rendered still more astonishing by the addition of strongly coloured non-fluorescent substances. Thus we see that yet other compound fluorescences than those belonging to class III. are possible, and may, indeed, be pro- duced artificially; viz., confining ourselves to only two fluores- cent substances, by mixing two substances of the first or two substances of the second class. A mixture of the first kind (of naphthaline-red with fluoresceine, or with eosine, for instance) may be easily recognised as such when examined by its spectrum ; their fluorescent spectrum consists of two parts separated by a minimum, neither of which follows Stokes's rule, but of which the second refrangible part (belonging to the fluoresceine or eos'ine) disappears, as soon as the incident homogeneous light has been diminished down to that limit, where it ceases to cause fluorescence in these substances. It is, however, more difficult to recognise a mixtm'e of two substances of the second class as such, as it behaves like a simple substance of that class. It is possible that amongst the substances enumerated in class II. there are mixtures of this nature, consisting of two or more substances not separated hitherto. The varying behavioiu- of the extracts of soot could, for instance, be easily explained by tte supposition that in soot there are contained two or more fluorescent substances of the second clas.', which are dissolved in vaiying proportions by the dissolving media. Herr Lommel did not feel justified in establishing separate classes for the two kinds of compound fluorescence just de- io8 NATURE {May 23, 1878 scribed, since no natural instance of the former kind is known up. to the present, and since the latter kind cannot be recognised as compound fluorescence by any optical means. THE ARTIFICIAL TRANSFORMATION OF THE ALPINE SALAMANDER THE success of Madame von Chauvin in producing the de- velopment of Amblystoma from the Mexican axolotl by gradually accustoming it to live in air, induced her to attempt a very interesting interference with the life-history of the black or Alpine salamander, Salamandra aira. This is an ovoviviparous species, and although its young possess large gills while within the body of the mother, they are born to commence a land life immediately ; while other species of salamander, especially the spotted one, S. maculata, found in adjacent districts to the subjcc: of inquiry, bring forth their young with gills, and they pass a considerable period in water before taking to land. The problem which it was desired to solve was, whether the young of the black salamander, taken from the mother before the normal time of birth, and placed in water under favourable conditions, could become adapted to an aquatic life. It is in- teresting to note that while only two eggs out of many come to full development in the black salamander, forty or fifty develop in the spotted one ; yet individuals of the two species are about equally numerous in their respective localities. This shows the value of the avoidance of life in water with its atten- dant risks, though probably the diminution of terrestrial enemies in the more elevated localities frequented by the black salaman- der is a considerable influence in its favour. Madame von Chauvin's researches are detailed in a recent number (vol. xxix. p. 324) of the Zeitschrift fiir wissenschaft- liche Zoologie. They commenced on July 30, 1875, '^ith twenty- three larvse taken in various stages of development ; eight were about I \ centimetres long, twelve were from i,\ to 5 centimetres, and had almost completed their metamorphosis into land sala- manders. One was a little less developed, 4*3 centimetres long, the gills and skin-glands were less perfect, and the skin was very transparent and unwrinkled. This larva, unlike the rest, ap- peared at ease when placed in water, and made no attempts to get out of it. The next problem was to feed the little creature, and the first attempt was made by supplying a number of various minute water insects ; but although it evinced some desire to catch them, the insects were able to escape capture, while the larva seemed to become annoyed by their presence. Later on, a minute earthworm being offered, it was taken and swallowed, and the problem was solved. A daily supply of the same food was thenceforth taken by the young salamander. The gills which the creature possessed in the oviduct appeared from the first little adapted for life in water ; they were of so thin a texture that they could hardly be expected to endure ex- posure and motion, while their great extent evidendy hampered the movement of the animal. Consequently the gills first became pale and bloodless, then shrank, and on the third day were entirely thrown off, down to the very base. But on the same day on the right side, a day later on the left, minute buds appeared, three on each side, which gradually enlarged into ball- like protuberances ; from these, after three weeks, gill- fringes were put forth, which finally numbered nine on the first pair of gills. The fringes were mostly arranged along the external border of the gills, and they assumed abrown-spotted character, while the blood- circulation through them became plainly perceptible. They were very much less extensive than the previous set of gills, but appeared to perform the work of respiration perfectly ; the creature remained completely beneath the surface of the water, without ever coming up to breathe air. While the new gills were being developed the larva remained at rest as if dead, only eating the earthworms when they were offered. When the gills had attained a length of 2*2 mm. the larva became lively, and concurrent with this was the completion of another transformation. The delicate and transparent swimming membrane of the tail was lost, and replaced by a less transparent and stouter one, of greater dimensions. The creature now seemed to enjoy life much more than before, exhibiting greater interest in its living food, with which it would play before swallowing it. Finally, after six weeks' residence in the water, a skin-shedding commenced, the skin coming away piecemeal for a fortnight. The larva continued to grow satisfactorily without undergoing further modification, until it had been fourteen weeks in the water, having attained a length of 6 centimetres. The gills then began to shrink, and the tail to assume a rounder form, ahd in three days the skin was shed, revealing the normal black and wrinkled skin of the land salamander. In nine days from their first shrinking the gills were nearly absorbed, only little stumps remaining. At last it crawled out of the water, and on the four- teenth day the gills were complttely absorbed and the gill clefts closed. The remaining larger larvte of this experiment lost their primary gills less satisfactorily and in a greater length oi time. New gills commenced to bud, but the creatures were gradually destroyed by fungus-growths attacking various parts of their skin. The fact that they were altogether more advanced in their metamorphosis rendered them unable to adapt themselves quickly to their new conditions. A second series of researches on the Alpine salamander was carried on in the summer of 1876, when a large number 0* individuals were collected at Thusis, at the confluence of the' Rhine and the Nolla. The animals were collected thirteen days earlier than in the previous year, so that the development of the young was not so forward. Thirty-three larvee were taken from the oviducts, eight of which were from 8 mm. to ^o mm. long, two 12 mm., and twenty-three from 35 mm. to 40mm. All had their skin still transparent and their gills not yet of full size. After twelve of them had refused insects, minute earthworms were administered to them, but they did not eat them till after some hours. Two larvre, immediately after being taken out of the mother and placed in the water, fastened respectively on the head and tail of a worm that was wriggling at the bottorn of the water. Their diflSculty was solved by cutting the worm in two, and each obtained half. This method of immediate feeding was thereafter successfully adopted, and it appeared to develop a good appetite in the larvie. One noteworthy circumstance in regard to these creatures was that, at a time when they would normally be still within the body of the parent, they were as active and as eager for food as new-bom larvK of the spotted salamander. They were often so greedy for their prey that they seized hold of the limb of a neighbour of their own kind instead of the desired worm. But nevertheless these creatures did not develop in the desired direc- tion, the gills did not begin to shrink quickly, and when they did they were not got rid of as a whole, but the dead portions, remaining attached to the body, became the seat of fungus growth, which speedily increased and spread so as to kill the animal. Thus none of ihe subjects of investigation really became adapted to their life in water. In two cases it was attempted to succeed artificially by cutting off the gills nearly at the base ; one died soon, owing to fungus growths, the other quickly became a land salamander. Experiments like the foregoing have the highest interest, for they mark out for us the actual path of adaptation to changed physical conditions. It appears highly probable that the spotted and the Alpine salamanders were at no very distant period of time one species, and that as physical conditions became changed one variety became more and more adapted to more elevated and rocky habitats, where water for the early life of the larvte was not commonly to be met with. Thus gradually the birth of the young was postponed, and they became non-aquatic ; con- currently fewer and fewer of the many eggs were developed. The spotted salamander, meanwhile, became more and more spe- cialised to inhabit the lowland districts. Such cases as Madame von Chauvin's, if they remained single instances, would suffice to establish natural selection as a vera causa of the mutation of species. G. T. Bettany UNIVERSITY AND EDUCATIONAL INTELLIGENCE Bristol.— The Council of University College have resolved to found an Engineering School in connection with the scientific and technical courses of instruction already established. It is announced that the scheme will meet with the support of the local engineering firms. In accordance with this scheme the lectureships in Mathematics and Experimental Physics have been elevated into professorships, and the present holders of the lectureships, J. F. Main, M.A., D.Sc, and S. P. Thompson, B.Sc, B.A., have been elected to the new chairs. It is stated that the new buildings of the College will be commenced at once, an excellent site having been secured several months ago. The number of students attending the present term exhibits a considerable increase upon the corresponding term of the preceding year. May 23, 1878] NATURE 109 SOCIETIES AND ACADEMIES London Royal Society, May 2. — " On the Reversal of the Lines of Metallic Vapour?," by G. D. Liveing, M.A,, Pro- fessor of Chemistry, and J. Dewar, M.A., Jacksonian Professor University of Cambridge, No. II. Since their last commmiication to the Society the authors have succeeded in reversing characteristic lines of the vapours of rubidium and caesium. They operated in glass tubes into which some dry rubidium or ccesium chloride was introduced, and a fragment of fresh cut sodium, and afterwards either dry hydrogen or dry nitrogen admitted, and the end of the tube sealed off at nearly the atmospheric pressure. Through these tubes placed lengthways in fi-ont of a spectroscope a lime-light was viewed. On warming the bulb of a tube in which rubidium chloride had been sealed up with sodium, very soon there appeared two dark lines near the extremity of the violet light identical in position with the well-known violet lines of rubidimn. Next appeared faintly the channelled spectrum of sodium in the green, and then a dark line in the blue, very sharp and decided, in the place of the more refrangible of the characteristic lines of caesium in the flame spectrum. As the temperature rose these dark lines, especially those in the violet, became sensibly broader ; and then another fine dark line appeared in the blue in the place of the less refrangible of the caesium blue lines. During this time no dark line could be observed in the red, but as the tem- perature rose a broad absorption band appeared in the red with its centre about midway between B and C, ill-defined at the edges, and though plainly visible not very dark. The lines in the violet had now become so broad as to touch each other and form one dark band. On cooling the absorption band in the red became gradually lighter without becoming defined, and was finally overpowered by the channelled spectrum of sodium in that region. The double dark line in the violet became sharply defined again as the temperature fell. There are two blue lines in the spectinim of rubidium taken with an induction-coil very near the two blue lines of caesium, but they are comparatively feeble, and the two dark lines in the blue which the authors observed in the places of the characteristic blue lines of caesium they believe must have been due to a small quantity of caesium chloi-ide in the sample of rubidmm chloride. When a tube containing caesium chloride and sodium was observed, in the same way as the former, the two dark lines in the blue were seen very soon after the heating began, and the more refrangible of them broadened out very sensibly as the temperature increased. The usual channelled spectrum of sodium was seen in the green, and an additional channelling appeared in the yellow, which may be due to caesium or to the mixture of the two metals. They have at present no metallic ccesium where- with to decide this question. Indeed the cajsium chloride used was not free from rabidium, and the dark lines of rubidium were distinctly seen in the violet. It is remarkable that these absorption lines of caesium coincide with the blue lines of ccesium as seen in the flame, or in the spark of an induction-coil without a jar, not with the green line which that metal shows when heated in an electric spark of high density. In like manner both the violet lines of rubidium are reversed in the tubes, and both these violet lines are seen when the spark of an induction-coil, without jar, is passed between beads of rubidium chloride fused on platinum wire, though only one of them appears when a Leyden jar is used. The authors have extended their observations on the absorp- tion of magnesium and of mixtures of magnesium with potassiimi and sodium, using iron tubes placed vertically in a small furnace fed with Welsh^coal, as described in their former communication. The result of several observations, when commercial mag- nesium {i.e., magnesium with only a small percentage of sodium in it) was used, is that the absorption produced by magnesium consists of — 1. Two sharp lines in the green, of which one, which is broader than the other, and appears to broaden as the tempera- ture increases, coincides in position with the least refrangible of the b group, while the other is less refrangible and has a wave- length very nearly 5,213. These lines are the first and the last to be seen and very constant, and they at first took them for the extreme lines of the b group, 2. A dark line in the blue, always more or less broad, difficult to measure exactly, but very near the place of the brightest blue line of magnesium. This line was not always visible, indeed rarely when magnesium alone was placed in the tube. It was better seen when a small quantity of potassium was added. The measure of the less refrangible edge of this band then gave a wave length of very nearly 4,615, 3, A third line or band in the green, rather more refrangible than the b group. This is best seen when potassium as well as magnesium is introduced into the tube, but it may also be seen with sodium and magnesium. The less refrangible edge of this band is sharply defined, and has a wave-length about 5, 140, and it fades away towards the blue. These absorptions are all seen both, when potassium and when sodium are used along with magnesium, and may be fairly ascribed to magnesium, or to magnesiiun together with hydrogen. But besides these other absorptions are seen which appear to be due to mixed vapours, 4, When sodium and magnesium are used together, a dark line, with ill-defined edges, is seen in the green, with a wave- length about 5, 300. This is the characteristic absorption of the mixed vapours of sodium and magnesium, it is not seen w ith either vapour separately, nor is it seen when potassium is used instead of sodium. 5. When potassium and magnesium are used together, a pair of dark lines are seen in the red. The less refrangible of these sometimes broadens into a band vnih. ill-defined edges, and has a mean wave length of about 6,580, The other is always a fine sharp line, with a-wave-length of about 6,475. These lines are aa regularly seen with the mixture of ix)tassium and magnesium as the above-mentioned line (5,300) is seen with the mixture of sodium and magnesium, but are not seen except with that mixture. 6. On one occasion, with a mixture of potassium and mag- nesium, another dark line was seen in the blue, with a wave- length nearly 4,820. This line is very near one of the bright lines, seen when sparks from an induction-coil, without a Leyden jar, are taken between electrodes of magnesium, and may very likely be due to magnesium alone, and not to the mixture of vapours, as we only observed it on one occasion. There is a certain resemblance between the absorptions above ascribed to magnesium and the emission spectrum seen when the sparks of a small induction-coil, without Leyden jar, are taken between electrodes of magnesium. This emission spec trum is the same, with the addition of some blue lines, as that seen when the sparks are taken from a solution of magnesium chloride, as accurately described by Lecocq de Boisbaudran, and as that seen in burning magnesium (Dr. Watts, P/iil. Mag., 1875). The pair of lines (l) correspond nearly with the b group, but slightly displaced towards the red ; the shaded band (3) corre- sponds less closely to the series of seven lines 5,000 to 4,930, which pro^essively decrease in brightness towards the blue, and is also a little less refrangible than that series; the broad line in the blue (2) corresponds to the pair of lines 4,570 and 4,590, and the remaining line (6) to the line 4,797; also both displaced a little towards the red. No absorption corre- sponding to the extreme lines 4,481 and 5,528 was observed. There is plainly no exact reversal except of the line b^, and even in that case it may be an accident if we suppose the two dark lines (i) to represent the extreme lines of the group b. It may be noted in connection with this that the absorption lines de- scribed by the authors in their former communication as seen with sodium and potassium (wave-lengths 5)5^° ^^^ Sj73o) ^^^ near to, but more refrangible than, well-known emission lines of those elements. They observe that there is in the solar spectrum an absorption line, hitherto unaccounted for, closely corresponding to each of the above-described absorption lines. Thus, on Angstrom and Thalen's map there are dark lines at 6,580 and 6,585, with more or less continuous absorption between them, a broad dark line between 6,474 ^^^^ 6,475, and a dark line at S>300. There are also dark lines nearly, if not exactly, coincident with the series of seven bright lines of magnesium above described, which they have not seen strictly reversed. The coincidences of the series of the solar spectrum hitherto observed have, for the most part, been with lines given by dense electric sparks ; while it is not improbable that the conditions of temperature, and the admix- tures of vapours in the upper part of the solar atmosphere, may resemble much more nearly those in their tubes. They intend to pursue their observations, using higher tem- peratures, if they can obtain tubes which will stand under those circumstances. no NATURE \_May 23, 1878 May 2, — "On the Determination of the Scale Value of a Thomson's Quadrant Electrometer used for Registering the Variations in Atmospheric Electricity at the Kew Obser- vatory," by G. M. Whipple, B.Sc, Superintendent of the Kew Observatory. The Meteorological Council, being desirous of discussing the photographic traces produced by their electrograph at the Kew Observatory some time since, requested the Kew Committee to institute a series of experiments, with the view of determining the scale value of the instrument, in order to prepare a suitable scale for measuring the curves. The author having found, in some preliminary experiments with 300 Bunsen's elements, that the greatest potential to be obtained with these was inadequate for his purpose, he was enabled through the kindness of Dr. De la Rue, to make use of that gentleman's large chloride of silver battery for determining the scale value of the electrometer. There were in all nine experiments ■ made, in five of which the deflections were read off with the eye, whilst in the remaining four they were registered by photography. Deflections were measured for potentials varying from o to 900 cells positive, and from o to 300 negative. By combining the results of these experiments and taking the means for every hundred cells, the following table is obtained : — POSITIVE. NEGATIVE. No. of Deflection in No. of Deflection in No. of Deflection in Cells. Inches. Cells. Inches. Cells. Inches. 100 o*93 600 3-95 100 1*04 200 177 700 4*20 200 2-34 300 2-48 800 4-42 300 375 400 3 "09 900 4-69 500 3-57 On laying down these values in a curve, making use only of those between the limits of - 200 and + 700, as the others are beyond the capability of correct registration by the electro- graph, a regular smooth curve is produced, which, being pro- jected upon one of the ordinates, gives a scale by means of which the electrograms are now easily tabulated. The value of the electromotive force of one De la Rue chlo- ride of silver cell being 1*03 volt, as determined by Messrs. De la Rue and Miiller {Proc. Roy. Soc, vol. xxvi. p. 324), the scale thus formed has been assumed to represent volts with suffi- cient accuracy for the required purpose. Chemical Society, May 2. — Dr. Gladstone, F.R.S., presi- dent, in the chair. — A lecture on the chemical aspects of vegetable physiology was delivered by Sidney H. Vines. The lectiu-er com- menced by giving a historical sketch of our knowledge of the absorption of carbonic acid and the evolution of oxygen by plants, the circulation of starch grains, and the functions and nature of chlorophyll. Sachs first proved that starch grains were not formed in plants which are bleached, from the absence of light, and that their formation in the chlorophyll corpuscles depended on the exposure of the plant to bright sunlight. Godlewski showed that if no carbonic acid was present no starch grains were formed. So there are two sets of phenomena, viz., the evolution of oxygen (with absorption of carbonic acid) and the formation of starch grains, for both of which three conditions are essential, viz., sunlight, chlorophyll, and carbonic acid. These two sets of phenomena are therefore probably connected and belong to the same function. Great diversity of opinion exists both as to the composition and functions of chlorophyll. The lecturer gave a short account of the views brought forward by Pringsheim, Karl Kraus, Pfaundler, Wiesner, &c., and entered more in detail into the' statements and theories advanced by Sachse. In the second part the lecturer considered the formation of vegetable acids, and pointed out that the views of Liebig and Mulder had not been confirmed by subsequent experiments. The part played by pyrocatechin, asparagin, &c., in the formation of carbohydrates was next considered, and the lecturer concluded by pointing out the necessity for quantitative work before we could hope to attain clearer and more certain views on the important functions of assimilation, excretion, &c., in the vegetable kingdom. Anthropological Institute, April 9. — John Evans, F.R.S., president, in the chair. — The following new Members were an- nounced : — Messrs. G. J. Romanes and R. J. Hutton. — Mr. W. M. Flinders Petrie read a paper on inductive metrology, the purpose of which, as explained by him, is to deduce the units of measure employed by ancient peoples from the dimensions of existing remains. Where units derived from several different buildings coincide, a high probability of the accuracy of the result in units is obtained. This principle has been tested by application to the monuments existing among the peoples of the Mediterranean. Mr. Petrie had also applied it to the earth- works of this country. At Hill Devereux he had obtained an unit of 691 inches. At Steeple Langford, an unit had been derived which varied only by 5 inches. Near Orcheston is an earthwork forming a perfect ellipse. From this Mr. Petrie argued a con- siderable knowledge of mensuration on the part of the flint- workers, by whom it had been constructed. He urged the necessity of accurate measurement on the part of observers. — Dr. E. B. Tylor read a paper on the game of PatoUi, in ancient Mexico, and its probable Asiatic origin. The game is a com- bination of dice and draughts. It was similar to a game called Patcheesi, in use in India, played by throwing cowries on to a board divided into squares of a certain pattern. So devoted are the natives to this game, that a story is told of a Provincial Governor who habitually won back his servants' wages from thera at it, and thus got served for nothing. Linnaean Society, May 2. — Dr. W. B. Carpenter, F.R.S., vice-president, in the chair. — M. C. Chambre and Mr. T. Comber were elected Fellows of the Society, and five Foreign Members, to fill the annual yacancies, were likewise unanimously elected. — Mr. J. R. Jackson exhibited specimens of fruits, leaves, and por- tions of the stem (used as a substitute for soap) illustrating pecu- liarities oiYucca baccata, Torrey. This plant extends from South Colorado far into Mexico. Northwards it is acaulescent, southwards it develops a trunk ten feet high. The fruit, a dark piu-ple berry, is preserved and eaten as winter provision, and the plant is com- monly known as the Rocky Mountain Banana. — A note was read from the Rev. H. H. Higgins concerning a large new Tubularian Hydrozoon (probably allied to Clava?) from New Zealand. — On behalf of Mr. Thomas Higgin there was ex- hibited a photograph of Chitina ericopsis. Carter, and also microscopic specimens of this rare species of the Hydrac- tiniidce from New Zealand. — Mr. J. C. Galton called attention to a spined dermal plate of the Ray tribe of fishes, mistaken for a fossil, and obtained near the Barking Priory. — The Secretary read in abstract a paper on Mampa, a genus of the Simaru- bacece, by Mr. J. Miers. This is founded on a curious fruit and specimens of -wood exhibited in the Brazilian department of the Paris Exhibition, 1857. Signor Netto, in 1856, described a Brazilian plant under the designation Odina francoana, and bearing the vernacular name " Pao Pombo," as did the above- mentioned woods. Mr. Miers, however, is of opinion that Netto's species cannot belong to Odina as that genus is Anacar- diaceous, and quite foreign to the American Continent. Then follows the technical characters of the new species Marupa francoana and M. paraensis. — A short paper was read by Mr. R. Irwin Lynch on the seed -structure and germination of a species of Pachira. The seeds were received at Kew, July, 1877, and labelled the " Provision Tree." Varying in size, they con- sist chiefly of one fleshy-lobed cotyledon, the second being exceedingly diminutive and functionless. Germination occurs in a fortnight after sowing, and in one instance the larger per- sistent cotyledon did not appear to be exhausted for nearly six months. — The main facts of a detailed communication on the occurrence of conidial fructification in the Mucorini, illustrated by Choanephora," by Dr. D. D. Cunningham, was, in his absence, read by the Secretary. According to observations and experimental investigations conducted for a series of years in India, Dr. Cunningham proved that Choanephora is a genus of Mucorine, and not Mucedine fungi, as Currey had regarded it in 1872. It is, moreover, capable of producing four kinds of fructification, as follows : — By (i.) Zygospores = sexual fnictifi cation ; by (2.) Conidia ; (3.) Sporangial spores ; and (4.) Chlamy« dophorous = asexual fructification. These phenomena afford a possible explanation of certain otherwise conflicting con- clusions which have been arrived at by such competent observers and authorities as Brefeld, Van Tieghem, and Le Monnier. At all events, it yields a note of warning that clasfi- fication of fungal organisms based alone on one form of fructi- fication may lead to false conclusions. The present researches likewise show that M. de Bary's suggested analogy between the Mucorini and Ascomycetes, fin -respect "pt their fructification. May 23, 1878] NATURE III is well founded, although the observations which originally suggested it have since been shown to be fallacious. Dr. Cun- ningham states that the presence of Choanephora on plants certainly greatly accelerates decay, but it is a cause, not a consequence, of advanced putrefaction. Physical Society, March 30.— Prof. \V. G. Adams, presi- dent, in the chair. — The following candidates were elected Members of the Society :— S. Bidwell, M.A., LL.B., W. Grant, E. Gurney, and J. H. Smith. — Mr. W. H. Preece described Byrne's pneumatic battery and exhibited some of the results that may be obtained by its means. It is especially devised with a view to provide the medical profession with a portable battery capable of producing a considerable amount of heat, as is required for cauterising operations. The negative plate consists of a very thin plate of platinum to which a lead backing is soldered, and this is covered with a sheet of thick copper also coated with lead, the whole being then covered with a non-con- ducting varnish with the exception of the exposed platinum face ; such an arrangement is found to be advantageous in that it increases the conductivity of the negative plate. Two of these plates are arranged to face the zinc plate as in Wollaston's form of cell, and the exciting liquid consists of twelve ounces of bichromate of potash, one pint of sulphuric acid, and five pints of water. By using such a mixture the sulphuric acid attacks the zinc and the three atoms of very loosely combined oxygen exercise a depolarising effect by absorbing the evolved hydrogen. A fine tube dips into the exciting liquid and is so arranged that it conducts a current of air, from a small pair of bellows, against the face of the negative plate ; by this means any bubbles of hydrogen are, as it were, brushed off, and the current obtained from a given electromotive force is materially augmented, since the resistance is diminished. Mr. Preece then referred to several old forms of battery in which such an agitating principle is introduced, notably those of Grenet, Chutaux, and Comacho, and he went on to describe a series of experiments he has made with a view to ascertain the cause of the great heating and illuminating effects that could be obtained with the apparatus exhibited. He showed that the effects were due to the mechanical agitation of the liquid on the face of the negative plate ; but whether the great production of heat in the battery, and the great lowering of its internal resistance were chemical, thermal, or electrical effects, remains for fm-ther investigation. By means of a small battery of four cells, in which the plates were 4 inches by 2 inches, a length of 6 inches of platinum wire. No. 18 (0*05 inchej), could be heated to bright redness, and much more powerful effects were obtained by a large battery of ten cells made by Ladd ; in this case, about 2 feet of a No. 14 (0*089 inches) wire were heated, and it was shown that, when connected with an 18-inch inductorium, kindly lent by Mr. Spottiswoode, sparks of over 17 inches could be obtained, but this length was reduced to about 8 inches on stopping the current of air. A similar effect was also very marked when the poles were con- nected with two carbon points, the light given out when the air- current was introduced being remarkably bright and steady. — Mr. Preece then exhibited an ingenious method of showing the vibrations of a telephone plate to an audience, which has been devised by Mr. II. Edmunds. A vibrating plate is employed to break contact as in Reiss's original telephone, and is intro- duced into the primary circuit of a small induction coil. The induced current is employed to illuminate a rapidly-rotating Gassiot's tube, and, on making and breaking contact by speaking into the resonator, an illuminated star is observed, the number of whose arms varies vith the pitch of the note ; with a very low note it may resolve itself into a single straight line. — Lord Rayleigh exhibited and explained an arrangement which he has employed Avith advantage in certain acoustical experiments, in order to secure absolute tiniformity in the rate of rotation of an axle. After referring to the mathematical principles involved in such a problem, he explained that the only hope of its solu- tion lay in the employment of a vibratory movement, which by some suitable device must be converted into a motion of rotation. The axle whose motion it is required to maintain uniform is usually driven, at an approximately uniform rate, by means of a small horizontal water-wheel, or, in some cases, the electro-m^netic regulating apparatus presently described is sufficient by itself to supply the necessary power. At equal distances round the axle are arranged four soft iron armatures which successively come in front of the poles of a horse-shoe electro-magnet placed in ltie circuit of a four-cell Grove's battery. The current is rendered intermittent by the following arrangement. Passin" into the body of a tuning-fork vibrating about forty times per second, it leaves by a small platinum stud which is touched at each vibration of the fork ; the current then traverses a second small electro-magnet between the prongs, and by this means the vibrations are maintained ; passing to the magnet above referred to the current then returns to the battery. The velocity of the axle is such that it performs about one complete revolution for every four vibrations of the fork, and the exact adjustment is effected as follows. If the driving power be just sufficient to produce the desired speed, the armatures will be so attracted by the magnet as to be exactly opposite to it at the middle of its period of magnetisation, and so long as this position is main- tained the magnet will not (on the whole) affect it. But if a disturbance occur in the driving power the armature will be displaced from its former position and will be attracted by the magnet until the error is compensated. Besides the armatures this axle also carries, concentric with it, a hollow metallic ring filled with water, and as this possesses a certain momentum in virtue of its rotation, it will act as a drag tending to check the velocity in case it increases, and in the converse manner when a diminution occurs. A blackened disc perforated with rings of holes of various numbers also rotates with the axle and by placing the eye behind the ring oi four holes and observing a prong of the fork it is easy to ascertain whether the uniformity is maintained, since in that case the prong will appear to remain stationary. Entomological Society, May i.— H. W. Bates, F.L.S., F.Z.S., president, in the chair. — Henry John Elwes, F.L.S., F.Z.S., of Cirencester, was elected an ordinary member, and Mr. Peter Cameron, jun., was elected a subscriber. Mr. Dunning drew attention to the fact that the present meeting marked the forty-fifth anniversary of the foundation of the Society. — Mr. Distant exhibited a specimen of the Hemipteron, Tetroda bilineata. Walk., as a remarkable instance of immunity from the effects of damp, the same having been kept in a relaxing-pan for more than four months. — Mr. Distant also com- municated a paper " Notes on some Hemiptera-Homoptera, with Descriptions of New Species," in which he drew attention to the uncertainty of generic calculations as to geographical distribu- tion, the Homoptera affording a good illustration in the family Cercopida, especially the genus Cercopis. Part i of the Transactions for 1878 was on the table. Royal Microscopical Society, May i. — H. J. Slack, pre- sident, in the chair. — Four new Fellows were elected, and Pro- fessor Abbe, of Jena, was elected an Honorary Fellow of the Society. — A paper by Mr. Michael, on new British Cheyleti was read by the Secretary. It minutely described the structure and habits of the insect, and was illustrated by drawings. The name proposed by its discoverer was Cheyldus flabellifer. — Mr. Chas. Stewart gave a resume oi a paper which had been received from Dr. Oscar Schmidt, of New Orleans, in continuation of a former communication on the blood-corpuscles of Amphiuma, frog, and man. The president suggested to the meeting a series of experiments, which he thought might be of value in the interpretation of optical images, by the examination of micro- scopic drawings of Lis; ajou ; curves under various powers. He also brought bafore the notice of the Fellows a species of fungus which he had found infesting the leaves of the bay, but which did not appear to derive its nutriment from the leaf itself. After some discussion, the fungus was identified by Dr. M. C. Cooke as Capnodium, Footii, which was stated to live upon the honey-dew found upon the surface of the leaves of a large number of trees, particularly in the autumn months. Institution of Civil Engineers, May 7. — Mr. Bateman, president, in the chair. — The paper read was on the construction of steam boilers adapted for very high pressures, by Mr. James Fortescue Flannery. Wellington, N. Z, Philosophical Society, December 11, 1877. — Mr. Carru- thers, C.E., the vice-president, occupied the chair. — Dr. Buller read a further paper on the ornithology of New Zealand. Among the species treated of were the Kaka parrot, with an interesting account of the Maori mode of trapping it by means of decoy birds ; the two species of migratory cuckoo, with observations on their parasitic habits ; the black fantail, the occurrence of which as far north as Auckland has been communicated by Mr. Cheesman ; the knot ( Tringa canutus) which has lately been met with in this island ; the sandpiper {Limnocinchis acuminatus), and many others. Among the latter 112 NA TURE \J^Iay 23, 1878 was the New Zealand godwit, of which the author gave an in- teresting sketch. This bird spends a portion of the year in Siberia, and visits in the course of its annual migration the islands of the Indian Archipelago, Polynesia, Australia, and New Zea- land. In summer it frequents the south coast of the Sea of Ochotsk, and it has likewise been observed in China, Japan, Java, Celebes, Timor, Norfolk Island, and the New Hebrides. They leave New Zealand towards the end of March or beginning of April, and return to us towards the end of November. —On Nephr odium decomposiium and N. glabellum by T. Kirk, F.L.S. — On Hymenophyllum montanum, a new species discovered by Mrs. Mason in the mountains between Lake Wakatipu and the West Coast, by T. K. Kirk, F.L.S.— On the relative ages of the Australian, Tasmanian, and New Zealand coalfields, by Dr. Hector, F.R.S. The speaker's remarks were illustrated by diagrams and maps, and by a large collection of fossils which he had obtained during a recent tour in the Australian colonies. Alter describing the extent and position of the various coalfields at present worked, he stated that from a comparison of the fossils he had arrived at the following results •.—Cretaceous epoch: Chief New Zealand coal ; wanting in Tasmania and Australia, except "perhaps in Queensland. Jurassic epoch : Mataura series of New Zealand ; Cape Paterson coalfields of Victoria ; Clarence River coal of New South Wales ; and the coalbeds at Hobarton. Liassic epoch : Clent Hill beds of New Zealand ; wanting in Tas- mania and Australia, except Queensland. Triassic epoch: Wairoa beds of New Zealand ; tipper coal formation of New South Wales ; and wanting in Tasmania. Periyiio-carboniferous : Maitai series of New Zealand ; lower coal formation of New South Wales ; Mersey coalfields of Tasmania. This view of the relative ages of those formations had just received remarkable confirmation by a late discovery. Mr. McKay, of the Geological Survey, who has recently been at work in the Canterbury Alps, having found plant beds beneath the spirife beds of Mount Potts that are full of the leaves of glossopteris, a fern very characteristic of the upper and middle coal formation of New South Wales, and with them beds of graphite of considerable commercial value, which represents in an altered form the Newcastle coal seams. Along with these occur remains of saurian reptiles of immense size, of which large collections have been made. In conclusion, it was stated that only a very small portion of the area coloured on the map of New South Wales as coal formation contained valuable coal seams, and that they were not without drawbacks. At Newcastle, where the principal collieries are situated, the seams have to be worked to an increasing depth by shafts, and require pumping. In the southern coalfield the coal is worked by adits into the face of the mountain, and lowered by steep inclines in the same manner as our own Buller coal will be worked ; but it has to be shipped from an exposed coast. The western district coal has all to be carried over the Blue Moun- tains by a railway that ascends and descends by zigzags, that answer well enough for passengers and light traffic, but must be rather costly for transporting coal. Dr. Hector stated that all he had seen increased his confidence in the value of our West Coast coalfields, both as regards the quality and^extent of the coal and the facilities for working it. Paris Academy of Sciences, May 13. — M. Fizeau in the chair. — The following among other papers were read : — Observation of the transit of Mercury, on May 6, at Montsouris Observatory, by M. Mouchez. The observations were vague, owing to the bad weather, but so far confirmed the theory of Mercury. M. Picard got three photographic images, two of which seemed very good, but there was no trace of the planet. M. Mouchez was struck with the much more rapid succession of the phases in the transit of Mercury than in that of Venus ; the times of contact should thus be obtainable with greater accuracy. — Re- searches on the law of Avogadro and Ampere, by M, Wurtz. Bioxalate of potassium becomes hydrated much in the same way in an atmosphere of hydrated chloral, and in one of moist air or chloroform, containing aqueous vapour with the same tension as the atmosphere of hydrated chloral. M. Wurtz infers that the latter is entirely dissociated.— M. Du Moncel read a paper on the Hughes microphone, from information communicated by Mr. Crookes. — Report on two memoirs of M. Dien, concerning ( i ) defective notes of instruments played with a bow, (2) resonance of the minor seventh in the grave chords of the piano. By placing small movable nuts on the short prolongations of the strings above the bridge, so as to tune those parts to the unison or octave of certain defective notes known in the violin, M. Dien gets rid of the disagreeable effect of the latter. In the second memoir he shows the resonance in question to be due to pressvure of the damper on touching one of the nodes which produces the triple harmonic minor seventh. He employs a second damper acting simultaneously with the other. — On the refraction of organic substances in the gaseous state, by M. Mascart. It appears, generally, that no method based on the sole considera- tion of elementary composition enables one to calculate the refraction of a compound from those of its constituents. The notion of equivalents of refraction does not apply to gases any more than to solids or liquids. Each case has its special con- siderations, not easily determined. — On the production of sul- phurised oils having insecticide properties, by MM. De La Loy^re and Muntz. The considerable amount of combined sulphur found in fetid oils got by distillation of the bituminous limestone of Orbagnoux, the authors augment by introducing sulphate of lime or pyrites into the mineral before distillation. — On the telephone, by M. Izam. A curious case of intelligible sounds being pro- duced in one single-wire telephone system, by a derivation of current from other systems through wet ground and a system of pipes. — On a new electric lamp with incandescence, acting in free air, by M. Reznier. If a thin rod of carbon, pressed laterally by an elastic contact, and pushed in the direction of -its axis, against a fixed contact, be traversed by a pretty strong current, it becomes incandescent at this part and burns, growing thinner towards the end. As the end gets used up, the rod, still pushed, slides in the elastic contact, always pressing against the other. The heat developed by passage of the current is greatly increased by the combustion of the carbon. — On a production of heat by chemical action, by M. Phipson. If a piece of chloride of lime be held in a rapid current of sulphuretted hydrogen from a narrow glass tube, the smell of sulphuretted hydrogen at once disappears, and is replaced by that of chlorine; a very light deposit of sulphiur is formed on the piece, which becomes too hot to hold in the fingers. The reactions here are notable. — Action of aqueous vapour on hydrocarbons raided to red temperature, by M. Coquillion. It facilitates their disso- ciation while producing a fall of temperature, which in blast furnaces is added to that caused by transformation of carbonic acid into carbonic oxide. — On investigation of ozone in atmo- spheric air, by M. Daremberg. He finds ozonoscopic researches useless. An ozonograph should be used which should expose the paper only during a few minutes. — Observations of the moon, made with meridian instruments of Paris Observatory during 1876, by M. Villarceau. CONTENTS Pagb . University Extension 85 Physical Sciekce for Artists, III. By J. Norman Lockver, F.R.S. (With Illmtraiions) 87 Clifford's Dynamic. By Prof. P. G. Tait 89 Physics of Volcanoes 9^ Our Book Shelf:— . _ _ Playf air's "Travels in the Footsteps of Bruce. —Prof. E. P. Wright 9^ Letters to the Editor : — On the Availability of Normal-Temperature Heat-Energy.— S. ToLVER Preston 9* " Underground Temperature."— William Morris 93 Helmholtz's Vowel Theory and the Phonograph.— Chas. R. Cross 93 The Telephone.— Alfred Chiddey 94 Hereditary Transmission.— Edmund Watt, Resident District Magistrate, Dominica, British West Indies 94 What is a " Water-shed " ?— R. H 94 Abnormal Coccyx.— Dr. Andrew Dunlop 94 Lecture Experiment.— Francis E. Nipher 94 Sound-emitting Crustaceans.— H. Stuart Wortley 95 Geographical Notes 95 Technical Education in University College, London .... 95 The Settle Cavh Exploration 9^ Organisation OF French Meteorology . . • • • •,••-• • ^6 Composite Portraits. By Francis Galton, F.R.S. (With Illus- trations) 97 The Seiches of the Lake of Geneva t>V ' ' ^*^ Examination of the PnoNOGRArH Record under the Micro- scope By Persifor Frazer, Jun., A.M. (With Illustration^ . . loi The Lifk-History of a Septic Organism. By the Rev. W. H. Dallinger,F.R.M.S ^°2 Our Astronomical Column : — The University Observatory, Oxford ^°3 The Cincinnati Observatory ^°3 The Reappearance of Encke's Comet i°4 Notes • ^°* Recent Researches on the Phenomena of Fluorescence ... 107 The Artificial Transformation of the Alpine Salamander. By G. T. Bettany '°7 University and Educational Intelligence 100 Societies and Academies '°9 NA TURE 113 THURSDAY, MAY 30, 1878 BALFOUR ON ELASMOBRANCH FISHES A Monograph on the Develop^nent of Elasmobranch Fishes. By F. M. Balfour, M.A., Fellow and Lecturer of Trinity College, Cambridge. (London : Macmillan and Co., 1878.) MR. BALFOUR has finally completed and issued in the form of an octavo volume the researches on the embryology of the dog-fish and its allies, which he commenced at the now celebrated zoological station of Naples in 1874, His results have been made known from time to time during the progress of his work by a prelimi- nary paper in the Quarterly Journal of Microscopical Science, October, 1 874, and by a series of articles in the Journal of Anatomy and Physiology, the latter, indeed, being identical with the successive chapters of the present volume. Looking at the work as a whole, we may heartily congratulate not only Mr. Balfour, but English science, on the very great value of this contribution to knowledge. Mr. Balfour, before entering upon the study of the deve- opment of the shark-like fishes, had thoroughly qualified himself for the task by a careful investigation of the de- velopment of the common fowl, a subject which, although it had always been and remains the favourite, be- cause the most handy, for the embryologist's study, yet yielded several new and interesting results to Mr. Balfour's examination. The methods which are ap- plicable to the hardening and slicing, staining and clarifying of the embryo chick are precisely those which it is necessary to employ in the investigation of the very similar tg^ of the Elasmobranchs, and accordingly Mr. Balfour had well trained himself [for the latter task. The prominent position in Vertebrate morphology which had been assigned to the group of Elasmobranch fishes, through the researches of Gegenbaur, rendered a minute examination of their developmental history urgent. It had become clear that we have in these fishes the nearest living representatives of the common ancestors of the great group of Gnathostomous Craniate Vertebrata, and it was to be expected that a full knowledge of their ontogeny or individual development would carry us yet further back in the line of "primitive Vertebrata, and yield a mass of explanatory evidence, exhibiting the develop- ment of complex and heterogeneous structures from simpler and more homogeneous forms, likely to serve as a satisfactory starting-point for all Vertebrate morphology. Mr. Balfour has shown in the course of his investiga- tion of this subject not only that he is possessed of the technical skill necessary for the manipulation of such embryos, but that he is gifted with a very large measure of patience and perseverance, and has, moreover, the high critical and speculative capacities which the subject demands for its full and successful treatment. We shall very briefly notice the successive chapters of Mr. Balfour's monograph, and point to the more im- portant novel observations [recorded, having especial regard to those which may be considered as fundamental for the morphology of Vertebrata, Mr. Balfour begins with the ovarian ovum of the Elasmo- branch, this portion of his observations having been made Vol. XVIII. — No. 448 on the skate. He shows that the germinal vesicle atrophies before impregnation. He then proceeds to describe the pro- cess of segmentation, which, in its general features, is similar to that of the bird, the only other ^%g containing so large a proportion of food-material mixed up with the protoplasm of the egg-cell . In the study of the division of the first- formed cells resulting from the segregation and cleavage of the mixed materials of the &gg, Mr. Balfour observed and has figured the remarkable spindle-shaped condition of the nuclei, which since has become such a prominent subject of investigation through the initiative of Auerbach, Strasburger, Biitschli, and van Beneden. Very remark- able and important nuclei are also described and figured as making their appearance in that part of the egg not concerned in the process of cleavage or the formation of the primitive disc of embryonic cells, and from their occurrence Mr. Balfour is led to the conclusion that the supposed distinction at this period of a purely embryonic and a purely nutritive region in the ^gg of the Elasmo- branch, is imaginary. This is important, because similar observations have necessitated the abandonment of similar erroneous divisions of the &gg of the fowl, of osseous fish, and of cephalopods. The mass of cells which form the smaU commencement of the embryo on the surface of the great unsegmented yelk-mass divide into an ectoderm and "lower layer-cells," and a true " segmentation cavity " comparable to that of the frog is described. The most important of Mr. Balfour's obser- vations and suggestions which have a general bearing upon the formation of the embryonic cell-layers through- out the Animal Kingdom are those in which he points out and gives its probable significance to the fact that in the Elasmobranchs the primitive alimentary cavity (archenteron) arises as a sort of in-pushing beneath the hinder end of the embryo, a cavity being there formed between the " lower-layer-cells " and the nucleated yolk. The orifice of this cavity is spoken of by Mr. Balfour as the " anus of Rusconi," and is identified by him accord- ingly with the orifice so named in Amphibians. At the same time it is tiot at this orifice that the final closure of overgrowing ectoderm or epi blast takes place, that is to say, of that layer of cells which, increasing by division, spreads from the cleavage disc so as to gradually cover in the whole of the large surface of uncleft yolk. The gradually narrowing margin of these epibolic cells does not in sharks have a centre coincident with the anus of Rusconi ; in fact, the blastopore, as the orifice bounded by this gradually narrowing margin is termed, lies behind the embryo altogether. Mr. Balfour suggests (and it is neces- sary to remember that his statements on this subject were first published three years ago) that the primitive-streak of the bird'' s blastoderm is a rudimentary representative of this portion of the blastopore; it seems necessary to say "this portion," and not the whole blastopore, as Mr. Bal- four does ; for tracing these various structures back with Mr. Balfour to the blastopore of the Amphioxus, we must admit that in the meroblastic ova of Sharks and Birds the blastopore has become greatly extended along the median line and has its most anterior portion represented in the anus of Rusconi of the Elasmobranch, a middle portion in the orifice of final closure of the elasmobranch's blasto- derm and the primitive streak of birds and mammals, whilst a more posteriorly placed extension of the same F 114 NATURE {May 30, 1878 structure (blastopore) is seen in the actual orifice of final closure of the bird' s blastoderm at the antembryonal pole of the yelk-sac. The continuity of the nervous and alimentary tubes, after closure of the Rusconian anus, is a striking feature which Mr. Balfour shows to be common to Elasmobranchs, Ganoids, Osseous fishes, Amphibians, Amphioxus, and Ascidians. To Kowalewsky we are indebted for the first observation of this remarkable dis- position in various types of lower Vertebrata, and its full significance is not yet understood. The next point of great importance which we find in Mr. Balfour's monograph is the derivation of the noto- chord from the hypoblast or archenteron, from which also the protovertebrae are developed constituting the meso- blast. That the vertebrates' body-cavity, like that of other animals, was primitively a portion of the alimen- tary cavity appears likely from this observation, coupled •with Kowalewsky' s more recent results as to the develop- ment of Amphioxus, whilst it also seems likely that the notochord made its first appearance as an organ apper- taining to the alimentary tract, from which it became gradually separated in function and in structure. The next thing which we come to is of even more special interest for the limited department of Vertebrate morphology. The unpaired and the paired fins alike make their first appearance in the Elasmobranchs as lateral ridges of epiblast, and Mr. Balfour accepts the hypothesis that the limbs are remnants of continuous lateral fins. The muscles of the limbs are shown to be derived from the "muscle-plates" of the body which develop from protovertebrae. It is to the nervous system that some of Mr. Balfour's most original and important observations have reference. He has elsewhere conclusively shown that, contrary to Stieda's statements and in accordance with Owsjan- nikow' s, the spinal nerves of Amphioxus have no anterior •roots, that is have only dorsal roots. He now shows that the early condition of the spinal nerres of Sharks agrees with this, they having at first no anterior roots. An enigmatical commissure parallel to the medulla unites the posterior roots in the embryo. The cranial nerves — exclu- sive of the first and second, and the nerves to the orbital muscles which have peculiar features of their own — are showntoretain permanently the primitive condition implied in the absence of anterior roots. The vagus nerve is shown to be the result of the morphological fusion or concrescence of several segmental nerves — their separate roots (which are all dorsal ones) being " caught " (so to speak) in the sharks in process of disappearance. The identity of the nature of these roots with those of the following spinal nerves is shown by the connection with them of the enigmatical commissure above mentioned. The segments which are represented in the Vertebrate liead have been reduced and blurred by the integration of that region of the axis, but by the aid of the embryonic relations of the cranial nerves, and of a very important and remarkable series of cavities representing the body- cavity of the head (the terms are not contradictory since "head" is chiefly developed from "body") in a seg- mented condition, which Mr. Balfour has discovered in the Elasmobranchs, he is able to indicate distinctly at least seven post-oral segments in the cephalic axis, and he adduces cogent reasons for supposing that a larger number existed, and have been suppressed by a kind of integration. As to the brain, Mr. Balfour gives important evidence against the fanciful interpretations of Miklucho-Maclay, whom, strangely enough, Gegenbaur has followed. What most persons call mid-brain, Miklucho-Maclay has identi- fied with the thalamencephalon or twixt-brain {Zwischen- him) of other Vertebrates, being induced by the large size of what is usually called the Elasmobranch cere- bellum to consider it as the mid-brain. Mr. Balfour gives strong embryological evidence against this view. As to the relation of nerves to the primitive germ layers, it is shown (in accordance with Hensen's observa- tions in Mammalia) that the spinal nerves are outgrowths of the medulla, and Mr. Balfour, though he is unable actually to demonstrate it, yet brings a variety of evidence to show that the whole growth of the nerves is a centri- fugal one, and that therefore the peripheral elements of the nervous system may have the same"primary origin as have the central. The important question as to how the axial medulla arose, and whether it is homogeneous with the ventral nerve-cord of Annelids and Insects is discussed in the light of the facts ascertained as to the development of the nerve-medulla in dog-fish. Mr. Balfour on the whole favours the view that the nervous system of elongated animals consisted primitively of two lateral cords, and that in Annelids and Insects these cords have met and fused below the alimentary tract, whilst in Vertebrates they have met and fused above the alimentary tract. A curious modification of a part of the nervous system, the meaning of which is as yet entirely beyond the most hazardous speculation of either physiologist or morpho- logist, is shown by Mr. Balfour to present itself in the supra-renal bodies. They develop from ganglia of the sympathetic portion of the nervous system. Lastly, we have to mention the series of results relating to the origin of the renal organs and the ducts of the generative system. These are already the most widely known and discussed, though possibly not actually the most important of Mr. Balfour's numerous discoveries. The fact that Prof. Semper, of Wiirzburg, occupied him- self with the investigation of the renal organs of Elasmo- branchs at the same time as did Mr. Balfour, and that the two investigators nearly simultaneously arrived at the same results, has given a special value to this part of the observations embodied in the present monograph. Mr. Balfour shows that the Vertebrate kidney is a condensation of tubules, of which primitively one pair existed in each segment of the body, opening into the body-cavity each by a ciliated funnel, and therefore exactly comparable to the segmental-organs or nephridia of the Annelids. Whether, as Gegenbaur holds, these organs were originally a simple pair which became segmented, that is, provided with a separate funnel in each metamere or body-segment, or whether each tubule or nephridium originally opened to the exterior, so that an unconnected series of nephridia existed on each side of the body — a pair in each segment — which subsequently became joined to one another by longitudinal common ducts— one on each side of the body — is still matter for consideration. The adaptation of the most anterior funnel to the May 30, 1878] NATURE 115 purposes of an oviduct, and of a portion of the middle tubules to those of sperm-ducts is what the observations of Balfour and Semper have established — and more especially the open funnel-like character of the tubules to begin with. Minor details and important confirmations of the more familiar facts of Vertebrate development I have not space to mention here, the whole series of embryonic pheno- mena is described with more or less detail by Mr. Balfour, and I have singled out the more striking facts and speculations of the monograph for brief notice. In commenting on such a work as this, it is strongly brought to one' s perception that the method of publication of the results of such laborious investigations is necessarily very imperfect— and subject to a serious deficiency in logical continuity and artistic effect. Mr. Balfour has studied the very widely-diverse phenomena of interest which the developing Elasmobranch presents from the first separation of the egg up to the nearly complete formation of all its organs. In order to state all the different results he has obtained, he is obliged, as is usual in embryological monographs, to give them in his- torical sequence. To the experienced student of embry- ology this method of statement and the presentation of drawings copied from actual sections and specimens is sufficient. It would be impossible to publish observa- tions within a reasonable period of the date of investiga- tion by pursuing any other method of statement. And yet the monographical and historical method, together with the objective "nature-true" drawings of sections is one which prevents an author from fully exhibiting the import of his observations, and from duly imparting to the reader in a clear and simple form what is, after all, the thing which the reader desires to know, namely, what is the net result of such observations in relation to the great questions of morphology. The fact is, there is no such thing as a science of embryology ; it is not even a defi- nite branch of a science. The development of organic form is a necessary part of the science of Organic Morphology, and the results of the study of development can be given with full clearness and in an intelligible manner only when formulated as parts of the general doctrine of the science under which they fall. The conclusion from this is, that the great value of Mr. Balfour's work will not be fully appreciated or rendered clear to the majority of zoological students until they are re-stated, not from the monographical standpoint ; but from the more general point of view of Animal Morphology. This more syste- matic exposition of his Elasmobranch studies and of other like researches in combination with a general survey of the morphology of all groups of the Animal Kingdom as revealed by their developmental histories, we may expect before long to receive from Mr. Balfour himself in the form of a continuation of his well-known Elements of Embryology. E. Ray Lankester OUR BOOK SHELF Gold. By Edwin W. Streeter, F.R.G.S. Fifth Thousand (London : Chapman and Hall.) The lettering on the cover of the book, as giren above •will hardly prepare the reader for the statement on the title-page, that the work is a translation and abridg- ment of Herr von Studnitz' "Die gesetzliche Regelung des Feingehaltes von Gold und Silber-Waaren," by Mrs. Brewer, with notes and additions by Mr. Streeter. The work itself contains information which it is useful to possess. It embodies brief abstracts of the law of various countries concerning the standard of gold and silver wares, and discusses the question whether the manufacture of articles in the precious metals should be subject to legal control. Mr. Streeter' s notes occupy 10 out of the 150 pages. He states that the system of "Hall-marking" was "instituted on the supposition that the assay and test of precious metals was a matter too recondite to render a power of adequate discrimina- tion for so valuable a transfer of property a thing reason- ably to be expected of the public generally." This is a very obscure way of saying that, as the value of gold and silver wares could not be recognised by in- spection, it was advisable that all articles should be stamped by authority. The necessity for such control has long been felt, and it was well justified in 1677 by the author of the "New Touchstone for Gold and Silver Wares," who says : "The truth is, the gain by adulterat- ing gold and silver works is so sweet and enticing that what excuse will not these adulterators find that they may have their unlawful liberty.' ' In London the control has been wisely vested in the Goldsmiths' Company since the fourteenth century, and in the country there are several assay offices which were reported on by a Select Committee of the House of Commons in 1856. Mr. Streeter urges that gold of one standard only — 18 carat — should be used, or that if other alloys are employed the tradesman should " mark them with his own name, state the value of the composite matter, and trust to his genius for the sale." Trusting to genius for the sale of articles is all very well, but the practice of a person stamping the wares he sells with his own mark surely affords no protection against the fraudu- lent tradesman as the marks are not likely to outlive the age in which they are impressed, and would be as readily counterfeited as those of a responsible authority. It should also be added that the initial or distinctive mark of the maker of an article of gold or silver is already included in the Hall mark. LETTERS TO THE EDITOR \The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to returny or to correspond with the writers of, rejected manuscripts. No notice is taken of anonymous communications. [The Editor urgently requests correspondents to keep their letters at short as possible. The pressure on his space is S0 great that it is impossible otherwise to ensure the appearance even ef com- munications containing interesting arui novel facts.^ Alternate and Stereoscopic Vision With reference to Mr. Galton's observation in his instructive paper in Nature, vol. xviii. p. 98, that "sometimes the image seen by the left eye prevails over that seen by the right, and vice versd," I may mention that, as I had noticed some years ago, this may be best observed without a stereoscope. If on looking at any object a few feet distant, a nearer object be placed about midway between the first and the eyes, there will of course be two images seen of the near, when the eyes converge on the distant ; one of these images seen, say by the right eye, overlaps the distant object as seen by the left eye, and if the two objects be about equally illuminated (or the near one rather the brighter), the overlapping image will alternately solidify and disappear, according to the alternate waxing and waning of sensibility in the eyes. This alternation may be made at will, by desiring to see the near or the distant object ; the fluctuations take place about every ten seconds normally, but the changes may be willed (though not so completely) as often as every second. If the observer can see stereoscopically without an instrument, i.e., can dissociate the usually coincident motions of focussing and convergence, this alternate action of the eyes is seen very ll6 NATURE {May 30, 1878 plainly ; and not only may stereographs be combined by the eyes, more readily and with less fatigue than when using an instrument, but they may as readily be inverted (the near objects appearing distant, and vice versd, as if falsely mounted) by applying each eye to the picture in front of the other, in fact, squinting at it. Thus, pictures of any size can be properly combined by reversing the pictures and crossing the eyes, and the width of the pictures is not limited to the distance between the eyes as in the ordinary way. An important use of stereoscopic vision is to throw one eye out of use when doing delicate measurement, &c., by directing it to some other and darker object, instead of shutting it ; this is less fatigue, and the attention may be willed on to the eye required, so that the image of the other is not noticed, especially if the eyes be changed occasionally. How far the fact of the eyes changing guard naturally by alternations, may suggest that all duplicated organs of the body have alternate periods of rest, I must leave physiologists to investigate. W. M. Flinders Petrie Bromley, Kent Inside Out It appears in Nature, vol. xviii. p. 105, that "if a fourth dimension were added to space, a closed material surface (or shell) could be turned inside out by simple flexure." This im- plies that flexure is necessary. But without displacing a point or a line in the surface we may consistently suppose a rotation of the normals at each point of it through two right angles in a plane polar to the tangent plane. That seems to do the business, C. J. Monro May 28 Physical Science for Artists Mr. Norman Lockyer, in Nature, vol. xviii., pp. 59, 60, gives some valuable hints to artists, which, if carried out, will go a great way towards preventing our eyes being hurt by the lunar monstrosities we see at the Royal Academy and elsewhere. May I be permitted to add a hint which he appears to have overlooked, and that is, that the inside boundary of a crescent moon is an ellipse ; and in this consists the peculiar beauty of a true crescent. The usual Turkish crescent is struck with two circles, and always looks gouty and bad. Of course the rough edge of a gibbous mooii is also an ellipse. Scientific Club, 7, Savile Row, W., Robert J, Lecky May 25 Dr. P, P. Carpenter's Collection May I ask you to correct an error in the "Notes" of your number for April 25th, relating to the collection of the late Dr. P, P, Carpenter, This collection was permanently placed by him in the museum of this university ; and, mounted under his direction on glass tablets, it now occupies a separate fire-proof room erected for it by the university, and constitutes one of the principal scientific treasures of this university and of Canada, Your correspondent was probably misled by the fact that one of the best duplicate sets was reserved by Dr, Carpenter for his own use in his private residence. This has not been pubUcly offered for sale, but I beheve has been privately offered to certain persons and institutions considered likely to value it, McGill College, Montreal, May 10 J. W, Dawson Menziesia Caerulea In confirmation of the recent occurrence of the above plant on the Sow of Athol, I may say that it was gathered by Miss Crawford in 1877, ^o^n vs'hom I received a specimen. Like the cotoneaster on the Orme, which has also been reported extinct, careful and prolonged search has generally been rewarded by finding specimens, although the cotoneaster is now very rare. I might take this opportunity of saying that the rare spider orchis, Ophrys aranifera, which the Rev. M. J, Berkeley has gathered at. Southorpe, in Northants, has been destroyed there by the planting of larch, I made a most careful search not only at Southorpe but on the Barnack hills last week, but without seeing a trace of the orchis, although Anemone Pulsatilla and Aceras antkrepophora are still abundant on the unplanted quarries, Northampton Natural History Society G, C Druce Landrails It would prove very interesting to know whether landrails are as plentiful in other parts of the country this season as they are in the neighbourhood of Sheffield. They have not visited us in any numbers since the spring and summer of 1875 ; in 1876 and 1877 scarcely one was heard ; while at the present time we hear their well-known calls in almost every meadow. I know of no migratory British bird in whose case this peculiar irregularity of appearance occurs in such high degree as in the landrail. If the advice of one interested in the subject may be humbly offered, I would recommend ornithologists to pay strict attention to this matter, this season, with a view of elucidating this peculiar trait in the life-history of this singular bird ; for the cause of this irregular appearance has, for thought I know to the contrary, yet to be learned, ' Charles Dixon Heeley, near Sheffield, May 20' Hereditary Transmission The letter of Mr. Watt reminds me of a similar instance of " Hereditary Transmission " mentioned in the ninth edition of the "Encyclopaedia Britannica." It is there stated that " George Bernhard Bilfinger was born on January 23, 1693, at Cannstadt, in Wiirtemberg. His father was a Lutheran minister. By a singularity of constitu- tion, hereditary in his family, Bilfinger came into the world with twelve fingers and as many toes." After being a Professor of Logic at St. Petersburg University Bilfinger became one of the "best and most enlightened ministers " of slate that Wiirtemberg had yet produced. Burngreave Road, Sheffield, George S. Watson May 25 THE PHONOGRAPH AND ITS FUTURE WHAT a surprise is in store for the children next Christmas if Mr. Edison's expectations are realised. Dolls that can say "papa" and "mamma," will be quite at a discount and will bear much the same relation to the doll of the future that the anthropoid ape does to the man of to-day, and the time will probably have come for some Darwinian toy-maker to write the history of doll development, if, indeed, he does not extend his researches to the whole world of toys. We are promised dolls that can speak, sing, cry, laugh ; musical-boxes that will grind out the voice and words of the human singer ; locomotives and every other species of "animal and mechanical toy," that will give out their natural and characteristic sounds. But these are only some of the trifles to which Mr. Edison, in an interesting article in the current North Ainericatt Review, tells us his miraculous invention will certainly or probably be put in the near future. And, indeed, a very little consideration will show that there is no end to the uses to which the principle of the phono- graph may be applied; that it may be the means of actually realising some of the wildest dreams and specu- lations of the "frenzied" poet and preacher, and creating a revolution in human intercourse only to be paralleled by the invention of printing, or even of speech itself. Indeed, at first sight it may seem a step back- wards, as it is likely to lead to the abolition, to some extent, of writing and printing, and the substitution of the human voice as the main means of intercourse at a distance. Talk of the solidification of the gases ! Why we have here the solidification of something infinitely more impalpable — human words and human thought. We referred above to the musical-box of the future, and this suggests the phonographic barrel-organ, which will doubtless by and by take the place of that instrument of torture which makes the lives of delicate-eared artists and litterateurs miserable. Instead of having our musical sensibilities harrowed by a murdered reproduction of our favourite operatic air, or our political sympathies shocked May 30, 1878] NATURE 117 by some wretched effusion of the Jingoid type, we shall have those picturesque Italian girls, with their bandit- looking companions, turning out for us a ballad by Sims Reeves or Santley, or a witching air in the voice of Patti. Alas ! the invention came just too late to preserve to us for ever the matchless voice of Titiens, for now we need not wish in vain for " the sound of a voice that is still." Music inevitably suggests love, and the tender cooings of the "lover and his lass, with a heigh and a ho and a heigh no nino." No longer will the far-separated pair have to wait weary weeks or months for a clumsy letter, when phonograph offices are as plentiful as telegraph stations ; and when Mr. Edison has managed to make those improvements on the instrument of which he is con- fident, it will be quite possible for the fond pair to have a daily meeting and exchange across the world all sorts of tender cooings — for sounds of every kind can be registered on and given out by the phonograph. Mr. Edison tells us that for these and similar purposes he is now perfecting the instrument in mechanical details. " The main utility of the phonograph, however, being for the purpose of letter-writing and other forms of dictation, the design is made with a view to its utility for that purpose. " The general principles of construction are a flat plate or disk, with spiral groove on the face, operated by clock- work underneath the plate ; the grooves are cut very closely together, so as to give a great total length to each inch of surface — a close calculation gives as the capacity of each sheet of foil, upon which the record is had, in the neighbourhood of 40,000 words. The sheets being but ten inches square, the cost is so trifling that but 100 words might be put upon a single sheet economically. " The practical application of this form of phonograph for communications is very simple. A sheet of foil is placed in the phonograph, the clock-work set in motion, and the matter dictated into the mouth-piece without other effort than when dictating to a stenographer. It is then removed, placed in a suitable form of envelope, and sent through the ordinary channels to the correspondent for whom designed. He, placing it upon his phonograph, starts his clock-work and listens to what his correspondent has to say. Inasmuch as it gives the tone of voice of his correspondent, it is ideniijfied. As it may be filed away as other letters, and at any subsequent time repro- duced, it is a perfect record. As two sheets of foil have been indented with the same facility as a single sheet, the * writer ' may thus keep a duplicate of his communi- cation. "The phonograph letters may be dictated at home, or in the office of a friend, the presence of a stenographer not being required. The dictation may be as rapid as the thoughts can be formed, or the lips utter them. The recipient may listen to his letters being read at a rate of from 1 50 to 200 words per minute, and at the same time busy himself about other matters. Interjections, expla- nations, emphasis, exclamations, etc., may be. thrown into such letters, ad libitum. "The advantages of such an innovation upon the present slow, tedious, and costly methods are too numer- ous, and too readily suggest themselves, to warrant their enumeration, while there are no disadvantages which will not disappear coincident with the general introduction of the new method." Then as to books there seems some chance that, ere long the printer's, if not the publisher's, occupation will be to a great extent gone, and the present unwieldy form of communication between an author and his readers be abolished. What would not one give to have the ''Christmas Carol" bottled up for ever in Dickens's own voice to be turned out at pleasure? Books, as Mr. Edison truly says, would often be listened to where none are read, and the possibilities of the instrument in this direction may be learned from the fact that a book of 40,000 words might be recorded on a single metal plate ten inches square. We need not point out the uses to which the invention might be put for the preservation of the greatest efforts of our greatest orators, but when Mr. Edison speaks of our thus collecting and preserving " the last words of the dying member of the family " and of great men, we feel as if he were approaching both the ludicrous and the shocking. Then the compositor will be able to set up his type by ear instead of eye, and we shall have phonographic clocks which " will tell you the hour of the day, call you to lunch, send your lover home at ten," &c. "Lastly, and in quite another direction, the phono- graph y^WS. perfect the telephone, and revolutionise present systems of telegraphy. That useful invention is now restricted in its field of operation by reason of the fact that it is a means of communication which leaves no record of its transactions, thus restricting its use to simple conversational chit-chat, and such unimportant detaUs of business as are not considered of sufficient im- portance to record. Were this different, and our tele- phone conversation automatically recorded, we should find the reverse of the present status of the telephone. It would be expressly resorted to as a means of perfect record. " * How can this application be made ? ' will probably be asked by those unfamiliar with either the telephone or phonograph. " Both these inventions cause a plate or disc to vibrate, and thus produce sound-waves in harmony with those of the voice of the speaker. A very simple device may be made by Avhich the one vibrating disc may be made to do duty for both the telephone and the phonograph, thus enabling the speaker to simtiltaneously transmit and record his message. What system of telegraphy can approach that ? A similar combination at the distant end of the wire enables the correspondent, if he is present, to hear it while it is being recorded. Thus we have a mere passage of words for the action, but a complete and durable record of those words as the result of that action. Can economy of time or money go further than to annihi- late time and space, and bottle up for posterity the mere utterance of man, without other effort on his part than to speak the vvords ? "The telegraph company of the future — and that no distant one — will be simply an organisation having a huge system of wires, central and sub-central stations, managed by skilled attendants, whose sole duty it wilL^jje to keep wires in proper repair, and give, by switch or shunt arrangement, prompt attention to subscriber No. 923 in New York, when he signals his desire to have private commimication with subscriber No. looi in Boston, for three minutes. The minor and totally in- consequent details which seem to arise as obstacles in the eyes of the groove-travelling telegraph-man, wedded to existing methods, will wholly disappear before that remorseless Juggernaut — " the needs of man ; " for, .will not the necessities of man surmount trifles in order to reap the full benefit of an invention which practically brings him face to face with whom he will; and, better still, doing the work of a conscientious and infallible scribe ?" Mr. Edison is certainly very hopeful of the ^future of the wonderful instrument he has invented, ,but we think, not too hopeful ; for, after the invention itself and its most recent development, the microphone, it would be rash to say that any application of it is impos- sible. Certainly some substitute or substitutes for.the clumsy mode of recording our thoughts by pen and ink, so inconsistent with the general rapidity of our time, must be close at hand; and what form one of these substitutes may take seems pretty clearly pointed out by the actual uses to which Mr. Edison's invention has been put. ii8 NATURE {May 30, 1878 THE ENGLISH ARCTIC EXPEDITION^ THE edge has been to some extent taken ofif the public appetite for a narrative of our last great Arctic expedition. The two ships had barely touched the Irish shores ere the papers of the day were teeming with details of the adventures and results of the expedition that had left England scarcely eighteen months before amid the enthusiasm of the nation, and with the strongest expecta- tions of eclipsing all previous expeditions, and returning with the long-sought-for secret of the pole. These news- paper narratives were shortly followed by Capt. Nares's report (which we gave in full with a map in Nature, yol. XV. p. 24), followed some months after by a thick Arctic blue-book, which those who have seen it may prefer, with its wealth of maps and illustrations, even to the two handsome volumes before us. (See Nature, vol. XV. p. 505.) Under these circumstances it will not be necessary for us to repeat the story of the Alert and Discovery. We shall endeavour briefly to sum up the main results obtained by the well equipped and much instructed expedition. Many a wonderful story lies buried in a blue-book; comparatively few, we believe, have seen the official narratives to which we refer above. The great majority of those, both at home and abroad, who are interested in the expedition commanded by Sir George Nares, have no doubt been waiting for the publication of these volumes, to learn all the details of the story of the hard- ships endured by our ever-brave sailors " far from all men's knowing," in the most inhospitable region under the heavens. The red-tapeism and stupid conservatism of our government are in nothing more forcibly exhibited than in their obstinate adherence to the unattractive " blue- book " for publications of all kinds that may be con- sidered in any way official. In this respect they present a marked contrast to the United States Government, the story of whose Polaris expedition was issued not long ago in a magnificently got-up volume that would do credit even to Messrs. Sampson Low and Co. ; and many of our readers must be familiar with the splendid library, issued at the expense of the Austrian Government, on the productive Novara expedition. We are sure Sir George Nares does not expect to be complimented on his skill as a raconteur ; he has wisely ' not attempted to do more than give a plain statement of the proceedings of the expedition day by day from the time it left England till its return. Those of our readers ^who have read the eloquent and methodical narrative of the Payer- Weyprecht expedition, when they look into the one before us, will not fail to be struck with the contrast in this respect. Still, we believe, by many. Sir George Nares's "plain, unvarnished tale" will be preferred to a carefully redacted and condensed narrative ; and we are sure that in his pages the simply told successes and failures of the English Arctic Expedition of 1875-76 will fascinate many a reader : it is almost impossible to make the story of an Arctic Expedition uninteresting. "The scope and primary object" of the expedition was, as contained in the " Sailing Orders," "to attain the highest northern latitude, and, if possible, to reach the North Pole, and from winter quarters to explore the adjacent coasts within the reach of travelling parties." Notwithstanding the ambiguous wording of these orders — no doubt " the highest northern latitude possible " was meant — it is a great mistake to imagine, as many did on the return of the expedition, that it was a failure because it did not reach the pole. No doubt it was a primary part of the programme to make the most determined attempt to reach 90° N. lat., and had "the People" not ' "Narrative of a Voyage to the Polar Sea during 1875-76, in H.M. ships AUri and Discovety." By Capt. Sir G. S. Nares, R.N., K.C.B., F.R.S., Commander cf the Expedition. With Notes on the Natural History, edited by H. W. Feilden, F.G S., C.M.Z.S , Naturalist to the Expedition. Two v.-ls. (London: Sampson Low and Co., 1878.) .^.^ been allowed to believe that this was the main object of the expedition, probably their enthusiasm at its departure would have been no greater than when the Challenger left our shores ; but, without doubt, the essential point in this matter was to get as far north as possible. No one who reads Sir George Nares's interesting but often sad pages will hesitate to conclude that if a higher latitude than that attained by the forlorn hope, led by Commander Markham, was not reached, neither officers nor men were to blame. Under hardships that could only be paralleled by those which led to the unknown deaths of the members of the Franklin expedition, was the attempt made to carry out the popular part of the programme — hardships, however, which did not surpass those endured by the sledging parties west and east under Aldrich and Beaumont. This is not the place to enter upon the question of the outbreak of scurvy, to which we have, indeed, referred in a former volume (xv. p. 505). After the searching inquiry of the Scurvy Commission ;_ after all that has been written on the subject in the public and medical journals ; and after a careful perusal of these pages, we are not inclined greatly to blame either Captain Nares or his officers for their neglect of lime-juice. Evidently we have yet much to learn about the causes and means of prevention of scurvy. All we have to do with here is the fact that under the most adverse conditions imaginable officers and men did more than could reason- ably have been demanded of them— though not expected of English sailors— to carry out the purely geographical part of their orders. Markham and his men really reached the highest latitude possible under the circum- stances, 83° 20' 26" N., the highest latitude reached by any expedition. "C'est magnifique, mais ce n'est pas la guerre." It was heroic, but it is not what we want. The other part of the geographical section of the pro- gramme was carried out with equal faithfulness by the sledge parties under Lieuts. Aldrich and Beaumont, and, in the case of the latter, under even greater hardships and with greater fatality than in the case of the northern party. Lieut. Aldrich succeeded in adding to our maps a stretch of 220 miles of coast along what may be re- garded as the northern boundary of America, while Lieut. Beaumont considerably extended our knowledge of the north coast of Greenland, and has given us reason to believe that it is bordered by islands. Many rectifica- tions were made, moreover, of the geography of the coasts and islands in Kennedy and Robesori channels, and a considerably fuller and more accurate idea of the nature of the coast regions both on the east and west sides of these channels. The fact is that, geographically, there appears to be little to discover in the region around the Alert's winter quarters, and what is really worth knowing in this direction could only be brought to light by an expedition colonised there for some years ; Capt. Howgate's proposed experiment will therefore be anxiously watched. Though it was often difficult to tell where the sea-ice ended and the land began, enough was observed both by Aldrich and Beaumont to indicate that these northern shores are mostly rocky, rising rapidly into hills and mountains, and often, especially on the Greenland side, steep and imposing, and deeply cut into by fiords. Markham saw no sign of land as far beyond his farthest north point as he could see, and seems in- clined to believe that if there is land it must be a great way off. Even had the men maintained their health and strength, it is doubtful if any of the sledging parties would have been able to do much more than they did, unless, indeed, they had been able to stay another winter, and make their furthest points bases for farther operations. The great hindrance to progress was the character of the ice which the sledge-parties had to traverse. The nature of this characteristic feature of these regions, the "paliEocrystic ice," as it has been named, is akeady May 30, 1878] NATURE 119 well known to our readers, and some further idea of it may be obtained from the specimen shown in our illustration (Fig. i). Things were bad enough for the shore-parties, but, to judge from the description, it would be as easy to go from the Crystal to the Alexandra Palace over the tops of the houses dragging a heavily-laden sledge after you, as to accomplish what Markham and his party did. The valuable result of this expedition is an extension of our knowledge of the nature and formation of the ice which covers these polar regions. That the inconceivably rugged and hilly nature of the ice is partly due to the movement of the pack, and the consequent piling of floe on floe at all sorts of angles, there can be no doubt ; but the observations of Dr. Moss (see our Royal Society Report this week) and Lieut. Parr seem to show that the immense thick- ness of the floes, exceeding eighty feet sometimes, is not due entirely to the piling of floe on floe. Rather it would seem that the same causes are in operation here as in the Alpine glaciers, and that on a thick substratum of sea-ice, snow-fall after snow-fall has been accumulating season after season, — for how long the daring geologist alone can hazard a guess — becoming gradually condensed into ice by pressure. What may be the limit of this process we have no data on which to build conclusions. "The N^vd-like stratification, the embedded atmospheric dust, and the chemical characters of our polar floes, indicate, in my (Dr. Moss's) opinion, that they are the accumulated snow-fall of ages, rendered brackish by in- filtration and efflorescence." The great " domed " floes, he thinks, tell of gradual decay, "because, wherever we got a section of them, the horizontal strata were cut by the outline of the domes, and the ice of the top of the dome was invariably salt. Occasionally deposits of atmospheric dust were to be met with throughout the stratified ice." Fig. I. — Newly.formed Flce-bergs. As to the movements of the ice in the Polar Ocean, the expedition was unable to make any observations of consequence, though it has made some contributions to a knowledge of those of the ice in the channels through which the ships passed. The general conclusion seems to be that beyond the Alerfs winter quarters, though there may be occasional open spaces, or polynias, the ice never breaks up sufficiently to enable a ship to pass further northwards, notwithstanding the observations made by the Polaiis expedition. But this question of the move- ments of the polar ice is just one of those that can only be satisfactorily settled by a long series of observations, such as those that could be made from the ring of stations proposed to be established by Lieut. Weyprecht. The tidal observations made, especially on board the Discovery, were of great value, in the opinion of Dr. Haughton, who gives an abstract of the results in the Appendix, and seem to confirm the observations made in the Polaris expedition :— " The expedition, proceeding up Smith Sound, met the tide coming from the north, at or near Cape Frazer, lat. 79° 40', and left behind the tides of Baffin's Bay. The new tidal wave, observed on board both ships, is specifically distinct from the Baffin's Bay tide, and from the tide that enters the Arctic Ocean through Behring's Straits ; and it is, without question, a tide that has passed from the Atlantic Ocean, round Greenland, northwards, and then westwards." As might be expected in these high northern regions, there were few auroral displays, and though one, at least, was remarkable, none were brilliant, and all comparatively colourless. We do not read, however, that any attempt was made to study this or any other light phenomenon by means of the spectroscope, though, we believe, several of the officers were specially instructed in the use of the in- strument before the expedition set out. In this connec- tion we may notice a most interesting solar phenomenon I20 NA TURE \May 30, 1878 exhibited on p. 300 of vol. i. (see Fig. 2), which will give the reader some idea as to how snow-blindness may- be produced, and which might have reminded Capt. Nares that the expedition was provided with the instru- ment we speak of. When the sun reaches a certain height, above 14°, during clear weather, "the most brilliant prismatic colours are displayed by each minute snow-prism, and in combination form a sparkling arc on the snow-covered ground, the bright light from which ^ too powerful for the unprotected eye. The * diamond-dust^' as we term it, becomes more open as the length of the radius is increased. Consequently, when the sun is between fourteen and twenty-three degrees in altitude, the refrac- tion of its rays is set forth with the greatest effect, and snow-bhndness has to be guarded against. In the bright arc, while each tiny prism displays its complete set of colours, the red tint is the most prominent nearest the Bun, the purple lying on the outside indistinctly defined." We regret that such observations were so rare, and that so little use was made by the expedition under Capt. Nares of the fine set of apparatus for physical observa- tions with which it was provided. This is the weak point of the expedition, and, so far as physical science is con- cerned, the "Arctic Manual" need hardly have been written. The 26th paragraph of the sailing orders runs : Fig. 2.— Diamond Dust. "The most approved instruments have been furnished to you for the purpose of pursuing research in the several branches of physical science, and as certain of your officers hare been specially instructed in the modes of observing, you will take care to give them every fair opportunity of adding their contributions thereto." Very few " fair opportunities " seem to have occurred to the expedition. But after all it is doubtful if the commander of the expedition is so much to blame. The truth is that the instructions to the expedition said more than should have been said about trying to reach the pole. What we wanted and what we still want are steady continued observations of meteorological and other phenomena in the polar area. The Royal Society might have saved itself all trouble if the instructions had been published beforehand. The comparative meagreness of the scien- tific results is, Ave believe, due more to the tone of the instructions than to Sir George Nares. Thanks mainly to Capt. Feilden, however, the expe- dition has not been altogether barren in scientific results, as the Appendix filling half the second volume will testify. With the exception of the short paper on the tides by Dr. Haughton, this appendix deals with the natural history and geology of the region visited. Each of the departments of natural history, from the mammalia downwards, has been worked out by a specialist, and the results, though seldom novel, are all highly interesting. Life was found in the sea at the highest point reached, and not far from the same point the tracks of a hare were seen. Dr. Hooker has some important observations to make in connection with the flora brought home, which confirms his previous conclusions as to the essentially Greenlandish nature of the Greenland flora. He is in- clined to think that vegetation may be more abundant in the interior of Greenland than is supposed, and that the glacier-bound coast-ranges of that country may protect a comparatively fertile interior. We are almost driven to conclude, he thinks, that Grinnell Land, as well as Greenland, are, instead of ice-capped, merely ice-girt lands. The geological results are fully and ably dis- cussed by Mr. De Ranee and Capt. Feilden, who indeed traverse summarily the whole ground of Arctic geology, to which their paper is a >^luable contribution. Their con- clusions are essentially the same as those already formed as to the very different climate that must have at one time prevailed in these regions. Dr. Coppinger' s report on the great glacier that discharges into the Petermanit Fjord is interesting, though his observations do not seem to agree entirely with Dr. Hooker's con- clusions. On the whole Sir George Nares' s two volumes confirm the opinions we have already " published with regard to this expedition. One and all exerted themselves nobly and bravely to carry out the main object of the expedition ; the results, geographical and scientific, brought home are of great value, and repay to a considerable extent the outlay and the hardships endured ; at the same time, now that the full narrative has been published, we must express regret that the scientific results are not more abundant than they are, and that they contrast so markedly with those of previous English expeditions, and with the expeditions of Germany and Austria, where, however, the officers are all trained men of science. Notwithstanding the results we cannot regret that the expedition was sent out ; it has solved the question of Arctic exploration so far that it is clear the Pole is not to be reached by the Smith Sound route — if at all, indeed by any means hitherto tried — unless some line of land be met with that will enable the sledge to be utilised. Meantime this narrative of the last great English Expedition will prove attractive and instructive to many readers. We cannot conclude without saying a word in praise of the many fine illustrations of Arctic scenery, a number of the finest being permanent Woodburytypes. There is also a large map showing the new discoveries, and a special one of Markham' s journeys. TRANSPLANTATION OF SHELLS TT is well known that animals and plants inhabiting ■*■ freshwater have, as a general rule, a very wide dis- tribution ; yet each river system, with all the pools and lakes in connection with it, seems completely cut off from every other system of the same country. Still more complete is the separation between the freshwaters of distinct continents or of islands ; nevertheless they often possess freshwater species in common. In my " Origin of Species" I have suggested various means of trans- portal; but as few facts on this head are positively known, the case given in the adjoined letter of a living Unio, which had caught one of the toes of a duck's foot May 30, 1878] NATURE 121 Dear Sir,- between its valves, and was secured in the act of being transported, seems to me well worth recording. Charles Darwin -The following case will, I think, prove of interest to you, as it corroborates your belief that freshwater shells are some- times transplanted by the agency of aquatic birds. In the sketch I have endeavoured to give you a correct idea of the way in which the shell was attached to the duck's foot. It was given to me by Mr. H. L. New- comb, who shot the bird, which was a blue- winged teal (Querquedula discors), while flying, near the Artichoke river at West Newbury, Mass., September 6, 1877. The shell, the common mussel, or clam {Unto complanatus), is a very abundant species, being found in nearly all the rivers and ponds of the Atlantic slope. How long the shell had been attached is only a matter of conjecture, but it had abraded the skin of the bird's toe, and left quite an im- pression. It was living when the bkd was shot. It would have undoubtedly been trans- planted to some pond or river, perhaps miles from its original home, had the bird not been shot, and might then have propagated its kind. Arthur H. Gray DaviVersport, Mass., May 8 To C. Darwin, Esq. THE NATIONAL WATER SUPPLY THE;JCongress convened by the Society of Arts, at the suggestion of His Royal Highness the Prince of Wales, their President — and which has been presided over by Sir Henry Cole, K.C.B., and numerously attended by Mayors of Provincial Towns, Chairmen of Local Sanitary Authorities, Medical Officers of Health, Members of the Thames Conservancy Board, Engineers, and men of science — may fairly be considered a suffi- ciently representative body to discuss with some amount of authority a national question. The papers prepared at the request of the Council of the Society, and discussed by the Congress, may con- veniently be divided into three groups : — the quantity of rainfall available for water-supply; the necessity of improved legislation to give it quickly and cheaply to the people ; the necessity of compulsory powers being given to a government department, to carry out the amended law. The first head, quantity available, was appropriately opened by a paper on the rainfall, by Mr. G. J. Symons, the indefatigable head of the 2,000 unpaid observers, whose results leave Httle to add to our knowledge upon this matter. "No part of the British Isles has, on the average, less than 20 inches of rain per annum," and *'the bulk of the supply falls upon elevated mountain tracts, where it ranges from 50 to more than 100 inches per annum.' ' Mr, Symons did not give the results of his expe- rience on the probable amount of the rainfall evapo- rated on different soils, under different atmospheric conditions, and in different .parts of the country ; this figure must ever be an important factor in estimating the quantity of water available in a district. Mr. John Evans, F.R.S., however, informed the congress that while on bare hard rocks nearly the whole of the rainfall is carried off by the surface strea?ns, on some porous rocks, such as chalk, an average quantity of not more than six or eight inches per annum finds its way to a depth of three feet from the surface, the re- mainder being carried off by evapo7-ation, and vegetation, and he adds " that for the supply of the population in districts of different geological character, different means must be adopted." Numerous speakers insisted at some length on the in- fluence of the varying degree of permeability of the rocks, in determining whether the rainfall is thrown off in floods, which should be collected and stored in reservoirs, or whether it is absorbed into the ground, where it can only be reached by wells, or by carefully preserving lines of springs. Mr. Chadwick, C.B., pointed out that the Map of the Geological Survey of the United Kingdom, and the other publications of this Department, formed an admirable basis for any inquiry into the water-bea,ring facilities of the British rocks. Mr. Whitaker's Memoir on the London Basin, which contains the particulars of more than 500 wells sunk in and around the Metropolis, is a good illustration of this, and useful as showing the facilities already possessed by a Government Department, which is capable of greater extension in this direction, and whose officers now constantly work in concert with those of the Local Government Board. Mr. Lucas exhibited a useful map, showing the under- ground contours of the surface of the water in the chalk, of some 800 square miles of the Thames and Hamp- shire basins, so that the level of the water in regard to the Ordnance datum line can be seen at a glance. He has also in some cases indicated the underground level of underlying impermeable strata, a method which has been long used in the Geological Maps of Paris ; and it is a matter of surprise that a map of London which should answer the purpose of a section in all directions was not published before. However useful such a map may be amongst the permeable rocks of the green- sand, chalk, oolites, and new red sandstones, which are penetrated by deep wells, — in the more ancient formations, consisting almost entirely of impermeable rocks, it would be impossible to construct such a map, and the ordinary- Geological Map is all that is required. These porous secondary strata occupy an area of 26,000 square miles in England and Wales, and in Scotland and Ireland are practically absent, and wells of any depth are rare ; while the more shallow wells, penetrating the over- lying drift, are in all districts, as pointed out by the Rivers Pollution Commission, dangerous sources of supply, though in some cases, as Prof. Prestwich, F.R.S., pointed out to the Congress, the gradual removal of cess- pools, and improvement of house-drainage, has caused the shallower well-waters to again improve. He, how- ever, gave a remarkable instance of a retrograde charac- ter, that of a deep " dry well," being carried through the London clay, to drain a cemetery near London, into the underlying Thanet Sands, which still give an important quota to the Metropolitan potable waters. Next to the quantity of water available, there is no question so important as the quality and purity ; and on this point Dr. Frankland gave important and reassuring evidence; for though he tells us that the increasing pollu- tion of rivers and streams " renders the supply of whole- some water from them more and more difficult," yet "two sources of wholesome water" still remain in England, viz., "upland surface water and subterranean water." The tables accompanying a paper laid before the Congress by Mr. De Ranee, show that the formations yielding water of these two characters occupy the following areas in England : — FORMATIONS YIELDING : — Subterranean Waters. Sq. Ms. Permian and Trias . . 8,645 Oolites 6,671 Hastings Sands,^ Green Sands, > . . 11,371 and Chalk ) 26,687 Moorland Waters. Sq. Ms. Granite, Metamorphic Rocks, Cambrian, Silurian, & Devonian 11,455 Carboniferous Rocks, (without the Carb. Limestone) .... 10,080 21,535 122 NATURE [May 30, 187& Of the more permeable rocks constituting the first list, probably four-fifths of the area would yield unpolluted water, and receive into its mass not less than six inches of rainfall annually, or a quantity, if all yielded up to wells, of no less than 240,000 gallons per day for each square mile of area. Of the second list the rocks are for the most part impermeable, and the most porous portion of the car- boniferous generally return the water that has percolated into the strata to the same river basin ; these rocks receive the heaviest rainfall of England, seldom falling below forty inches, and often rising to more than a hundred, of which quantity not less than thirty inches per annum may safely be calculated on, as the quantity run off by streams. Assuming that the rainfall is only available for water supply purposes, over one-tenth of the area, or 2,153 square miles, and that one- third of the supply is given back to the streams as compensation to manufacturers, to preserve fish, and for the purposes of inland navigation, the quantity remaining off this selected tract would be more than sufficient for the whole population of England, without recourse to the subterranean supply, which Dr. Frankland more especially recommends for domestic use ; so that there can be no shadow of doubt that the quantity of water available for supply to towns and rural populations, of a standard of purity approved by Dr. Frankland, is far in excess of the requirements of our population. The question of the amount of compensation water which should be returned to streams which are im- pounded for the purpose of water-supply is one of the gravest national importance. In one case, the River Roddlesworth, taken by the Liverpool Corporation Waterworks, the Legislature permitted " the compensa- tion water," ordered to be returned to the stream by the Act of 1847, to be bought up, for the purpose of supplying a new reservoir, and thus deprived the district drained by the stream, in the words of Mr. Bateman, speaking of a similar proposal,' " of all possible participation in the extension of manufactures and in the commercial prosperity of the surrounding district." Mr. Bateman has strongly expressed similar views in his evidence before the Duke of Richmond's Commission, and it is with regret, we notice that though he proposes to take eventually 50 million gallons per day from Thirlmere, he only intends to return 5|' million gallons a day to St. John's Beck. On the second head, the necessity of legislation to give cheaper and more easily acquired water powers to sanitary authorities, through the agency of provisional orders of the Local Government Board — which do not now possess compulsory powers to acquire water-rights, under the Local Government Act of 1875. Mr. A. H. Brown, M.P., read a paper describing the work done by the Select Committee on the Public Health Amendment Bill, of which he was chairman, and which has now been read a third time in the House of Commons and passed. The Bill introduces many sweeping changes, and not only gives to the Local Government Board increased powers, but empowers them " to confer the powers of this Bill or any of them to urban authorities," and further ordains that the Board shall hare power to permit Local Boards to purchase water compulsorily, under provisional orders, confirmed by Parliament, " such Provisional Orders to put in force the Water Clauses Act, 1847." Should Mr. Brown' s Bill pass the Upper House but little additional legislation would appear to be necessary, for the labours of the various Royal Commissions, Parliamentary Committees, and the British Association Committee of Inquiry "into the Secondary rocks of England, as a source of water supply," have amassed, as we have seen, ^ "Borough of Liverpool New Water Supply Report," by Mr. John Frederick Bateman, C.E., F.R.S. Liverpool, 1875. •The compensation of 13J million gallons, stated in several journals, and lately quoted by us, is incorrect, the amount being only si- a large volume of information as to the rainfall, available yield, and quality of the water suitable for domestic pur- poses; and the new powers obtained by the Local Govern- ment Board will enable them more quickly and cheaply to give facilities for the construction of works for water supply than heretofore. All that is still wanting, should the Bill pass, is some further machinery for ascertaining by Government inspection what rural districts and isolated hamlets are not at present properly supplied, and how the difficulty is to be solved. The Congress have met it by passing a resolution to "urge upon Her Majesty's Government the importance of taking steps, with the least possible delay, by means of a small scientific commission to investigate and collect, for the information of the public, the facts connected with water supply, in the various districts throughout the United' Kingdom, in order to facilitate the utihsation of the national sources of water supply for the benefit of the country as a whole, as suggested by H.R.H. the Prince of Wales." The high value and important "character of the work done by several bodies similarly constituted to the pro- posed Water Commission is so well known, that it would be needless to mention as examples the Charity, Civil Service, and Ecclesiastical Commissioners, were it not to point out that these gentlemen exercise functions of a special character, which could not well be undertaken by any other Government department ; while in the case of the proposed Water Commission, this very important raison d'etre appears to be absent, for special knowledge and long experience appear to be already possessed by. the staff of the Local Government Board, and by that of the Geological Survey, which under the interchange system of Government officers recommended by Dr. Lyon Playfair's Commission could easily be directed to assist them, especially as to a limited extent it already does so, and has besides aided the Rivers Pollution Com- mission in its labours.' The Congress has certainly been useful in showing how impossible it is to separate water supply from drainage, and the absolute necessity of there being a central authority, with supreme power over water, whether at the surface or underground, whether Jised for the purpose of water supply, canalisation, supplying motive power, or disposed of in the form of drainage and sewer- age. As Dr. G. W. Child well remarked, "the bane of all local government in England is the chaos of different and often conflicting authorities, existing each for a special purpose." How the formation of the proposed permanent Water Commission will facilitate matters by adding another to the long list of governing bodies it is difficult to see. Facts are useful ; but we first want simplification and unification of the law, and the carrying out its pro- visions entrusted to one central authority, directed by a Minister of Public Health, with power so to modify and increase his department as to be able to collect informa- tion at the same time that he administers the law, and remove from us the possibility of the reproach that we have carried on scientific investigations to complete our knowledge of water supply, without applying, for the use of our population and the prevention of disease, the information we already possess. PHYSICAL SCIENCE FOR ARTISTS'" IV. AM afraid there is no use in shirking the notion that my last paper may have seemed Avofully dull, fright- fully technical, and terribly wide of the mark to some artists who took it up, always supposing of course that « Annual Reports of the Science and Art Department. ^ Cont.r.ued frcm p. 89. I 3Iaj' 30, 1878] NATURE- 12 any of them did. Although I must plead not guilty to the last count, still I am so persuaded that in the nature of things these opinions were likely to be held that I feel compelled, before I go further into the experimentation with our improvised spectroscope, to draw attention to the kind of knowledge I hope to show can be gained by its use. It might at first sight appear that, limiting ourselves to the sun as a great radiator of light, the artist has only to do with white light in his pictures. This is true in one sense, but only in one sense ; for the artist has to deal with sunlight after it has been filtered through — after it has been absorbed by — many substances, notably the aqueous vapour of our air, and after reflection from others. I shall show in the sequel, for instance, precisely how it is that the sun is red at sunset ; at such a time as this the sun practically gives us coloured light because our atmosphere has abstracted from it some of the constituent rays which fell on the upper air. A familiar instance of this may be referred to. The colour of a ripe cornfield, in an autumn sunset, comes from the fact that, for the moment, in consequence of this absorptive eflfect, our sun has been a red star instead of a white one. Cause and effect are there before our eyes, and science connects them, and yet, alas, i have seen pictures in which the grand colour of the corn "has been given in perfection, while the painter has been so ignorant of the cause of it that he has given us a cold, grey, cloudy sunset, instead of a red, cloudless one. Further, as all the ordinary colours of natural objects depend upon the way in which they reflect or absorb white light, the colours of all must change at the hour of sunset or sunrise, if the light which they usually transmit to us is wanting in the light which they then receive. An object, for instance, which appears blue at noonday will appear tlack if only the red light of sunset falls upon it. The blue sky over head is really a rich source of light of all colours ; it is not a true blue, it is a mixture of blue and white ; so that sunrise and sunset effects are much more potent when a great bank of cloud overhead leaves only the eastern or western horizon open. A striking thing for an artist to observe under this condition is the difference of luminosity of a red brick house, and such objects as trees and fields ; the house seems glowing with light as if it were red hot, and for the simple reason that it gets as much light of the red kind, which is what it wants, and which it reflects to us, from the setting sun, as it does from the noon- day one ; whereas the trees and grass are no longer supplied with that light which they throw back to us usually, and so appear black for the same reason that lampblack appears black at noonday. It has been a favourite theme with many astronomers to enlarge upon the marvellous coloured phenomena which must take place in those planets which are near enough to stars of strongly contrasted colours to receive their light, now from one, and now from the other, producing not only a perfect modulation and combination of the colours of both, but also the strongest contrasts, such as, for instance, the setting of a red sun followed by the opposite rising of a blue one. No doubt such phenomena would be very enthralling, but to my mind the chromatic effects produced by the aqueous vapour in our own air absorbing the various elements in the light of our single white sun when it is not more than ten degrees above the horizon, supply us with a world of beauty with which we may well be content, and I for one have not found the beauty one whit less enthralling since I have endeavoured to picture to myself the causes to which it is due. All this, however, by way of anticipation : the causes so far as I am acquainted with them at work in the circum- -stances I have named, and in ten thousand others, are easily to be got at by a little simple experimentation. In my last paper I suggested a simple form of spectro- -cope. Here is a figure which will show how the prism should be placed and what it will do to the light commg through the slit C. Fig. I. -Shewing arrangement of iUt and prism,"] We may place a lens behind the prism as shown in Fig. 2, and throw an image on a screen, which may con- veniently be a piece of white paper. Fig. 2.— Introduction of a lens to produce an image. If we are content to use the lens and screen which constitute the human eye it must be placed near the prism. An expenditure of a few shillings is all that is required to enable the origin of one class of coloured phenomena to be investigated, that class, namely, in which the colour is due to the giving out, by the light source, of certain kinds of light only. This money should be expended in buying two little glass or brass tubes, ^ inch and \ inch in diameter, and 5 inches long, a little glass tubmg of very small bore, a few inches of platinum wire, a small quan- tity of red and green fire, and india-rubber tubing to convey gas from an ordinary burner to a table. Of the two tubes a Bunsen burner can be easily constructed 124 NATURE \_May 30, 1878 This is an apparatus for burning a mixture of ordinary gas and air ; the gas should be supplied through the smaller tube inserted into the lower end of the larger one, as shown in Fig, 3. The gas should be lit by holding a Fig. 3. — Bunsen burner, ordinary form, a, ext«rior tube ; s, holes to admit the air. match some 4 inches above the upper orifice of the wide tube. One end of the platinum wire may be fused into l!i!liirill|!!!l!|' Fig. 4. — Improvised Bunsen burner the piece of glass tubing, and the other twisted] into a loop, fine enough to hold some common salt in the flame. A piece of coke or charcoal soaked in salt and water will Fig. 5.- ^ do almost -Method of inserting platinum wire and salt into the flame. as well. This tube may be supported by a''piece of wood after the fashion of Fig. 5. The Bunsen burner will give us a very hot bluish flame, into which the loop of platinum containing common salt, sodic chloride, may be inserted, as shown in the accompanying woodcut. We shall get a brilliant yellow flame, which is worth notice on its own account, and if the artist is performing these experiments in his studio, let him look at some of his choicest pic- tures by means of this light, before he goes any further. He will be considerably surprised at their appearance, and I hope he will set himself to think about the cause of it — a point on which there will be a good deal to be said in the sequel. It will be better, however, to get at the physics in the first instance. To do this, put the impro- yised Bunsen burner and the platinum wire with the salt on it in front of the slit, and look at the slit through the prism ; it will be found that there is only a yellow image of the slit visible. If the things have been nicely arranged, the appearance of the spectrum will be so entirely changed that a beginner will be apt to fancy that something has gone wrong. Nothing has gone wrong however ; we have simply passed from the spectrum of polychromatic to that of monochromatic light — from white light to coloured light. These experiments touching the giving out of light can be easily and cheaply varied by burning green and red fire in front of the slit; the effect of these differently- coloured lights on a picture is also very striking. The next thing we have to do then is to represent the action of an absorbing body,— to study the action of our theoretical screen — the action of bodies when they absorb light, and therefore transform the origmal colour which that light possessed. Liquids will form our most convenient screen to illustrate this, and they can be placed in a " cell " like that shown in the accom- panying woodcut. Fig. 6. — Common^fonn of cell to hold solutions. It will not be necessary to buy such an apparatus ; two squares of glass, with a piece of india-rubber tubing between them, bent in the shape of a U ; the glasses be- ing kept in contact with the tubing by two india-rubber bands, form a cell which is wonderfully tight, and will serve our present purpose. This cell should be placed in front of the slit. A little potassic permanganate added to the water in the cell, will act as a screen, and cut off the yellow part of the spectrum, and the adjacent regions of the orange and green. Solutions of blood or magenta will give also very definite indications of absorption, and if we have one of those handy little pocket spectroscopes, which now, I am glad to think, are becoming common, the absorption of the light of a candle by the blood in the lobe of a friend's ear, or in the interval between two closed fingers can be well seen by placing it between the slit and the light. Let us now sum up as tersely as may be the con- clusions at which we have so far arrived. I. White light analysed by a prism gives us a con- tinuous spectrum. May 30, 1878] NATURE. 125 II. Coloured light analysed by a prism gives us a dis- continuous spectrum. III. Light may be coloured because originally_ the series of its components was not complete. IV. Light may be coloured because although the series of its components was once complete, some parts of the light have been absorbed in its passage to the eye. V. The bodies which give us white light are generally complex as to their molecules. VI. The bodies which give rise to the phenomena of bright or dark lines are generally simple as to their molecules. I now begin, with fear and trembling, to touch upon a part of my subject in which I ought to be the first to acknowledge that our ideas are not of the sure and certain kind. In what has gone before I have been careful to point out that, though the effect of incandescent bodies in producing and absorbing light was not likely to be directly applied by the artist, it was still in this sure and certain region that he should endeavour to follow the workings of laws clearly made out which might be in force elsewhere. This brings me to state that in my opinion the colours of most natural bodies depend upon the fact that there are definite molecular states of all kinds of matter lying between those two extreme stages to the phenomena presented by which attention has been directed. Some years ago, in a communication to the Royal Society, I drew attention to evidence which seemed to indicate that many substances which emit under certain conditions a white light giving a continuous spectrum, and coloured light associated with the spec- trum of lines under others, exist also in molecular group- ings between these extreme conditions, giving us for one grouping a continuous spectrum at the red end, and for the other a continuous spectrum in the blue. This is the most general statement that I can make, and I make it on account of the utility of such a state- ment. It has not yet been proved to be universally true, but the evidence I have already accumulated justifies me in setting it up as a working hypothesis. Not least valid among the lines of evidence on which I rely is the curious fact that the colours of almost all natural bodies can be at once explained by assuming them to be built up of these two molecular groupings to which I have called attention. Let us take gold as an instance. It is yellow ; but why is it yellow ? Because the molecules of gold, as I believe, generally exist in two complexities, one of them compe- tent to harmonise with the red rays of light, and therefore to absorb them, the other doing the same thing with the blue light, and for the same reason. Gum a piece of gold leaf on a piece of glass for easy manipulation, and look at a bright light through it ; it will be seen that the gold is green, or, in other words, that the blue and red have been absorbed, we have W 0 © © Y @ ^ changed into V I B©YOR by tme set of molecules stopping VIB and another YOR The reason that we get yellow light by reflection is that more of the central light is reflected than is transmitted. If we do not consider reflection, the thing becomes simpler: for instance, if I take a tube one foot long and fill it with chlorine gas, and observe the spectrum of a white light through the tube, we find that chlorine absorbs only in the blue ; the yellow and red are freely transmitted ; a glass coloured red is so coloured because its molecules absorb the blue, and a blue glass is blue because it absorbs the red. Prof. Stokes, in one of his lectures in South Kensing- ton, dealt with the colours of natural bodies in connec- tion with the absorption of light by them, and I may be permitted to close the present paper with the following extract from so great an authority : — " What is the cause why a green leaf is green, or why a red poppy is red ? It is frequently said that the reason why a red poppy is red and that a white lily is white is, that the lily reflects rays of all kinds, but the poppy reflects only the red ones, and if you place the red poppy in a pure spectrum it is luminous, like a white lily, in the red ; but if you place it in the green it will be almost black, whereas the white lily Avill be brilliantly green. Now the common explanation, properly understood, is true ; but it is not the Avhole truth, and if understood as it is liable to be understood, it is false. It is true that a red poppy reflects red rays, and a white lily reflects rays of all colours ; but it is not true that the preference for the red to the green in the one case and the equality of action in the other takes place in the act of reflection. It is not a phenomenon of coloration by reflection. The coloured light is reflected or you would not see it ; it is sent out of its course before it enters your eye, and it is true that the light, in its life's history, undergoes reflection ; it is not true that it is in the act of reflection that the one colour gets the preference over the other. Here I have some solution of the colouring matter of green leaves in alcohol, and here is some more alcohol, with which I will dilute the former. I have obtained a beau- tiful green solution, although the green colour is not seen now by reflected, but by transmitted light. As regards the light which falls upon the surface there is a little white light reflected, just a s there would be from water, but very little is reflected from the surface where the fluid is in contact with the glass, the chief portion of that re- flected being from the outer surface of the glass itself. You would not see any green at all in it unless there Avere something placed behind so as to reflect the light back- wards. You see there that the colour of the green leaf, as ordinarily seen, is due to the combination of reflection with the phenomena of absorption, or the swallowing up of certain kinds of light when light is sent through a perfectly clear medium. I may illustrate this in another manner. Here is a vessel of water into which I will pour some blue solution. If I send light through it, it will appear of a deep blue, but if I hinder the light from coming behind, which I can do by putting black cloth behind it, it is simply dark ; you do not see the blue colour at all. Why? Because there is nothing behind to reflect the light. Suppose I make it a little muddy by pouring into it some pounded chalk, you see the blue colour immediately. Why is that ? You know that if powdered chalk were put into water it would not colour the fluid. But here each Uttle particle of uncoloured chalk reflects a small quantity of light falling upon it, so that it fulfils the same office as a mirror placed behind the fluid. You may imagine that the particles of chalk are so many minute mirrors capable of reflecting light. If you take any one particle of chalk, say one-tenth of an inch deep, in the liquid, the light from the sky falls upon the fluid, it undergoes absorption in passing through that first tenth of an inch, and then the portion of light which is left is reflected by that little particle of chalk, and passes out again, and so, as regards that single particle, the light which reaches your eye from beneath that depth has itself gone through a stratum of fluid of one-fifth of an inch in thickness, and accordingly you see the colours produced by selective absorption ; that is to say, by the absorption of certain kinds of light, which are more greedily devoured by the fluid than the other kinds. This is what takes place in the green leaf and in 126 NATURE [May 30. 1878 the petals of flowers. Let us take the white lily. If the petal of the flower had been merely a sheet of thin glass you would not hare seen that white colour. There would have been a little light reflected from the first surface and the back surface, but the petal is really composed of a vast assemblage of little cells, at each of which partial reflection takes place, so that it re- sembles some finely-powdered glass, which would form a white powder, because each little surface is capable of reflecting the light, although a single sheet of glass would not be white. The petal of the white lily is just in the condition of the powder. It is full of little cells, full, optically speaking, of irregularities, from each of which a portion of light is reflected, so that, all kinds being reflected alike, and there being nothing in the white lily to cause preferential selection of one over the other — nothing to sift the light, as it were — you get a considerable quantity of light reflected back to the eye, but it is white. What is the difference between that and the red poppy ? The red poppy is, as it were, a white lily infused with a red fluid ; there is light continually reflected backwards and forwards, just as before, at the surface of the cells ; but that light, in going and coming, passes through the coloured juice of the plant. It is the same thing with a green leaf. The structure is irregular, optically consi- dered ; there are constantly reflections, backwards and forwards, of light, which penetrates a little depth and is reflected, and has to pass through a certain stratum of this colouring matter, to which the name chlorophyll has been given, but which is really a mixture. That is what takes place generally as regards the coloration of bodies ; it is a phenomenon not of reflection, not of selection of one kind of light for more copious reflection than another, but of absorption, or the swallowing up of certain kinds of light. Reflection comes in in order to enable us to see the light which otherwise would not enter the eye at all, but would go off in another direction." J. Norman Lockyer COSMIC METEOROLOGY SEVERAL articles have appeared at different times under the title of "La M^t^orologie Cosmique," from the pen of M. Faye : the last and most complete forms an exceedingly interesting " Notice Scientifique," appended to the Aimuaire of the Bureau des Longitudes for 1878. In this memoir, written with the usual clear- ness and talent of the distinguished French astronomer, a number of results connected with real or supposed solar, lunar, and planetary actions on our earth are ex- amined and criticised. As M. Faye has omitted several facts of considerable importance in his " Notice," and has misunderstood others, a reconsideration of some of the questions he has studied, with the additional light to be obtained from the facts alluded to, may not be without interest and use. M. Faye's thesis is giren in the first words of his article " Meteorological phenomena have their origin in solar heat." It is added, "This is now no longer suffi- cient. Cosmic influences are introduced, those of the planets, of the spots and rotation of the sun, of shooting- stars, the moon, and besides these, magnetic and electric actions are supposed to intervene incessantly between the bodies of the solar system." I shall refer to some of the most important questions under their different heads. The Moon's Influence in producing Atmospheric Varia- tions.— The popular beliefs in the moon's influence on the weather are first disposed of; they are conclusions from unrecorded observations where the coincidences are remembered and the oppositions are forgotten ; and they are opposed to strict deductions when all the facts are ■employed. Agreeing, as all men of science do, with this decision, the question remains. Whether the moon may not have some slight effect in producing meteorological variations ? She reflects, absorbs, and radiates the solar heat ; may this heat, in accordance with the thesis, not produce some effect on our atmosphere ? Sir John Herschel had observed the tendency to' disap- pearance of clouds under the full moon ; this he con- sidered a fact which might be explained by the absorption of the radiated lunar heat in the upper strata of our atmosphere. He cited Humboldt' s statement as to the fact being well known to pilots and seamen of Spanish America. I may add the testimony of Barnardin de St, Pierre, who, in his "Voyage kl'Ile de Reunion," says : " I remarked constantly that the rising of the moon dissipated the clouds in a marked way. Two hours after rising, the sky is perfectly clear " (" Avril, 1768 "). Her- schel also cited in favour of his "meteorological fact," a result supported by the authority of Arago, that rather more rain falls near new than near full moon. Arago' s conclusion that the phenomenon was "incon- testable of a connection existing between the number of rainy days and the phases of the moon " was founded on the observations of Schiibler, of Bouvard and of Eisen- lohr, three series which, on the whole, confirmed each other. Schiibler also, as Arago showed, had found that the quantity of rain which fell was greater near new than near full moon. These results, accepted by Arago, have not been noticed by M. Faye when he cites Herschel only, as one of those " men of science who interest them- selves in popular prejudices, take bravely their defence in hand and exert themselves to furnish not facts but argu- ments in their favour." It seems, indeed, to have been forgotten that Herschel' s argument was given to explain what he considered a meteorological fact. M. Faye founds his argument wholly on the conclu- sions of M. Schiaparelli from a weather register kept at Vigevano by Dr. Serafini during thirty-eight years (1827- 1864).^ The Italian physician entered the weather as clear, cloudy or mixed {misti), or rainy from morning to evening. M. Schiaparelli finds from this register that the sky was clearest in the first quarter of the moon. It has not been remarked that if the moon' s heat has any effect in dissipating clouds, as Herschel and others believed, this must be seen best when the moon is near full, that is to say, during the night hours, for which Dr. Serafini' s register has nothing to say. In confirmation of the conclusion that the moon does not dissipate the clouds, another result from the Vigevano weather jegister is cited, namely, that the greatest number of rainy days happens near full moon. This result is opposed to that derived from the observations of Schiibler, Bouvard, and Eisenlohr. The value to be given to observations of the number of rainy days must evidently depend on whether the observa- tions include the rainy nights ; and an investigation on this question, to have any considerable weight, should depend rather on the measured rainfall than on the term " rainy day," for which no distinct definition is given. The great objection to M. Faye's conclusions, as far as the facts go, is to be found in their entire dependence on tha Vigevano weather register {da mane a sera). No notice is taken of other observations and results showing a lunar action on our atmosphere, such as those already mentioned, which Arago considered incontestable, those of Madler and Kreil, and the more recent investiga- tions of Mr. Park Harrison and Prof. Balfour Stewart. All of these, and many others, must be carefully considered before we can accept the conclusion that the moon has no influence on our atmosphere. The subject is, how- ever, too large to be entered into here at present, and it will be possible to study it better after other conclusions of the learned French Academician have been examined. There is, however, a part of the argument, whatever the results obtained may say, which merits particular ' Memorie del R. Istituto Lombardo, L. lo. May 30, 1 8 78 J NATURE \2J. consideration ; and that is, that the moon' s heat cannot produce the phenomena in question. M. Faye shows that if the moon' s reflected heat is in the same proportion as the reflected light, such heat cannot produce a change of temperature of a thousandth of a degree Fahrenheit. I would remark that Lord Rosse's carefully-made experi- ments with the most delicate apparatus have shown for the total heat radiated and reflected, nearly ten times the proportion given by the reflected light ; but, as M. Faye observes, if the proportion were increased a hundredfold the effect would still be insensible. " How then," it is added, "can we expect such an action to dissipate the clouds when that of the sun does not always succeed ?" If, however, we can establish that real lunar actions exist which cannot be explained by the moon's heat reflected or radiated, the only philosophical conclusion will be that the moon must act in some other way, which it will be in the interests of science to seek out. Influence of the Sun-spots on the Earth's Magnetism. — It has been found that since the first accurate series of magnetic observations, towards the end of last century, to the present time, the maximum and minimum of sun- spot frequency have occurred at the same times as those of the diurnal oscillation of the magnetic needle; but because Dr. Wolf has believed that in the interval between 1787 and 181 8, when the observations of both phenomena were very incomplete, there were only two cycles for both, and because Dr. Lamont and myself believe there were three for both, M. Faye concludes that the mean length of the period for the magnetic needle was different from that for the sun-spots. The true conclusion is— if Dr. Wolf is right the mean length of the period for both phenomena since 1787 is nearly twelve years ; if the other view is right the mean length for both is 10-45 years. I have already considered this question in Nature (vol. xvii. p. 262). The egalit^ rigoureuse of the lengths of the periods sought by M. Faye is thus established whatever view be taken. It is next sought to show that any variation in the earth's magnetism in the decennial period cannot be due to variations in the solar heat produced by the spots. Founding on Mr. Langley's observations for the tempe- rature of the photosphere, of the nucleus and the penumbra of spots, M. Faye shows, making use as before of the absolute temperature of the earth, that the variation of temperature due to the spotted surface of the sun cannot exceed ± o°-3 Fahr. _ I venture here to remark, in the first place, that I have given strong grounds elsewhere for believing that the sun-spots are not the cause of the decennial period in the magnetic variations ; but that both are due to the action of a common cause.^ I quite accept then M. Faye's conclusion. It may, however, be argued that more heat proceeds from the sun in years of many, than in those of few, spots, but the observations of temperature, which have been made with so much accuracy in many countries for the last twenty years, will prove at once that no marked variation of the mean temperature occurs in the decennial period. We must here, however, consider the reasoning which has been employed on this subject. It is shown that the variation of temperature due to the spotted suiface of the sun cannot explain the change in the amplitude of the diurnal oscillations of the needle. It is, however, a mere assumption that this oscillation is due to the solar heat an assumption for which there is really no sound basis' unless some very rude attempts at a hypothesis can be so considered. M. Faye says, " This phenomenon is absolutely general ; ' " On the Decennial Period P- 593). and goes on increasing thence towards the poles," This variation of range is afterwards compared with the inverse law for the diurnal variation of the barometer, the range of which diminishes from the tropics towards the poles. This view, however, is founded on a misconception of the facts ; we might just as well say that the earth' s mag- netic force diminishes from the equator towards the poles (which is just the reverse of the truth), because its horizontal component does so. The mode in which this movement varies in amount from the tropics towards the poles appears to be imperfectly known, and as it is essential to make this clear before we can compare the facts with any hypothesis, I shall now attempt to do so. Diurnal Variation of the Magnetic Declination. — The horizontally suspended magnetic needle performs an oscil- lation in twenty-four hours, during which the north end is most westerlyin the northern hemisphere, and most easterly in the southern hemisphere, between i and 2 P.M. If we consider needles at different stations on the same meri- dian, it might be supposed that as we approached the- equator this opposition of movement would result in the- needle becoming stationary. That was Arago's conclu- sion. This idea, however, neglected the position of the sun. The range of the oscillation is greatest in our hemisphere when the sun is north, and greatest in the southern hemisphere when the sun is south of the equator. It is only when the sun has the intermediate position, near the time of the equinoxes, that the forces^ are nearly balanced at equatorial stations. If we suspend an unmagnetic steel needle horizontally on its centre of gravity, so that it can move both in a horizontal and vertical plane, and then magnetise it, the needle dips with one end below, the other above, the horizontal plane passing through its centre ; and the direction in which it lies is that of the earth's magnetic force. If this needle moves up, or down, or sideways,, this is because other forces pull it one Avay or another, or because the direction of the earth's magnetic force has- changed. Let us suppose in the first instance that the latter hypothesis is the true one, that is to say, that the earth's magnetic axis moves with the sun, the north pole having the greatest movement when the sun is in the northern hemisphere. If the dipping needle moves in. the plane perpendicular to the vertical plane, through an. angle u, and we wish to know what would have been the corresponding movements eastwards or westwards, if the needle had been made horizontal, by the addition of a small weight to the end above the horizontal plane, we must divide the angle u by the cosine of the dip below the horizon. Now in England the cosine of the dip is about \, so that the horizontal needle would have moved through an angle of 3 u. We obtain similarly the former from the latter by multiplying by the cosine of the dip. We may now see, from observations made at different stations, what is the range of the monthly mean diurnaL variation of the horizontal needle multiplied by cosine dip in a month for which it is a maximum in the northern hemisphere. The following are approximations to the mean ranges thus obtained from several years observa- tions in the month of August for the northern hemi- sphere. Station. Makerstoun ... Toronto Simla Bombay Madras Trevandrum ... In a similar way we find for the month of February for southern stations — Lat. Dip. Range of her. needle X cos. dip. 56 N. . . 71 N. ... 4'o 44 » • • 75 » - 3'5 31 .. • • 42 „ ... 4-6 19 .. • • 19 » - 5-4 13 » • . 8„ ... 4-8 9 ., • . 3S. ... 3-6 128 NATURE \_May 30, 1878 St. Helena 16 S. ..- 22 S. ... 4-8 Cape of Good Hope 34,, ... 53.. ••• 4*6 Hobarton ' 43 .. ••• 7° ,, ••. 4'3 It will be seen that in the months in which the sun's action is a maximum/ for each hemisphere the east and west movements of the needle in its true position (that which is independent of gravity) do not vary with lati- tude ; the maximum range appears, in fact, to take place near the tropics, and when the sun is in the zenith. If, however, we should prefer to consider the oscilla- tions of the horizontal needle due to the direct action of electrical currents upon it rather than upon the earth, we must remember the change of the force which directs the needle as we proceed from one latitude to another. If we wish to compare the vertical heights through which a body will fall in a second of time on an inclined plane at two stations, we must take into account not only the force of gravity at each station, but also the angle which the inclined plane makes with the horizontal plane. When we employ the same unit of directive force at the stations in the north hemisphere for the month of August, we obtain the following comparative ranges : — Makerstoun ... 4*3 Toronto ... 4'8 Simla 4*4 Bombay ... 4*6 Madras 3*8 (September = 4-2). The values are less for Trevandrum and St. Helena, but there is no appearance of a law which can be referred to latitude ; and there is no way in which we can examine the question which will satisfy such a relation. If we take any zone or zones of the earth which will include as much of the northern as the southern hemisphere, the mean movement for them will be nearly zero, on account of the opposite directions of the oscillations ; it is for this reason that there is a diminution of range, especially in the months near the equinoxes, for equatorial stations. On the whole the conclusion is, that the diurnal law of oscillation east and west of a magnetic needle is nearly the same in all latitudes for a given position of the sun and a given directive force. The deviations from this rule are connected with magnetic disturbances which have most effect near the poles, and with the opposition of forces near the equator. We have thus to deal with a phenomenon which is little dependent upon local causes, and which may, in its great features, be con- sidered cosmic. 2 These facts understood, we are now in a better position to consider the great change in the range of this oscilla- tion, which occurs in the decennial and sun-spot period. Let us examine what that change really is. It does not matter here whether we refer to the motion of the horizontal or of the dipping needle; we find that if the mean range is counted 10 in England in the years when it is a minimum, the years of fewest spots, then it becomes 16 or thereby when it is a maximum, that is, in the years for which the sunspots are most numerous. Now this great change in the effect of the solar action is felt in nearly the same way, and to the same proportionate amount, all over the globe. The law of the oscillation is not changed; the needle attains the most westerly position in one hemisphere, and the most easterly in the other, at the same hour as before, but the oscillation is nearly sixty per cent, greater at Hobarton in Van Diemen Island, at Trevandrum on the magnetic equator, at Toronto in Canada, and in England. When the observations have been continued sufficiently long with equal care, we can find that the ratio of the maximum range to the minimum is undergoing, at some " The month of maximum varies within the tropics : at Madras it is in September, and for that month the range multiplied by cos. dip — 5' "3 nearly. _ . ., ,, 2 For these reasons no such inverse relation with latitude exists as M. Faye has supposed between the diurnal oscillation of the magnetic needle and of the barometer. stations at least, a slow change. Thus, at Trevandrum the successive ratios of the maximum of i860 and 1870 to the preceding and following minima are — ^S6o __^ i860 ^.__ 1870 1870 I856' ^^' 1866' ^^ ' Im' ^^ ' 1877' 1-51. It must be remembered that the thesis which M. Faye supports is, that the diurnal oscillations of the magnetic needle are due to the solar heat, and that he has shown that no appreciable change of temperature is due to the spotted surface of the sun. We may ask then, Where are we to find the change of temperature which causes so great a variation in the sun' s action ? We need not calculate the difference of temperature between the photosphere and the nucleus of a spot, and we need not theorise on the possible difference between the solar radiation when there are few and many spots ; we have got thermometers; we have even observations of the evaporation of water, from which solar action M. Faye finds the atmospheric electricity which should produce the magnetic variations. What do they say ? If effects have any relation whatever to their causes, surely when the effect of the solar action in producing the diurnal varia- tions of the earth's magnetism is increased by a half or three-quarters of its value from the time of most spots till the sun shines with unspotted surface, we should expect some marked changes of temperature from year to year, if change of temperature is in question. I have already remarked that no such change of temperature has been found. M. Faye says with reference to the question, What is the cause of the decennial magnetic variation ? " The question would perhaps be embarrassing if we had only that to ask, but the elements of terrestrial magnetism pre- sent other variations which are as much independent of the sun-spots. Such are the secular changes which dis- place gradually the magnetic poles of our terrestrial globe. We must seek the cause not in the heavens but in the slow modifications of which the earth' s surface is the theatre. They are due probably to the works of men and above all to the continued action of geological forces." Of course these ideas refer to the secular changes, even for which they will not be readily accepted, but they do not touch on the fact that an explanation is offered, that of the solar heat, for the diurnal variations, and that no evidence is produced that the supposed cause undergoes any change in the decennial period. I have referred only to oscillations of the magnetic needle, which may be considered due to the variations of an easterly force ; but the force of the earth' s magnetism which directs the needle north and south, obeys also a law of diurnal variation, and the range of this variation follows the same law in the decennial period as that for the ranges of the oscillations. Thus at Trevandrum, near the magnetic equator, the ran^e of the diurnal variation of the total force of the earth's magnetism in the year for which it was a maximum, was to the range in the year of minimum as 177 to 10. The corresponding ratio of the ranges for the oscillations of the needle having been as 15-9 to 10.^ As there is not the slightest evidence of a decennial variation in the solar heat, and as there is an absolute certainty that if any variation exists it is of an amount so very small that it could not account for the great changes in the magnetic variations, the conclusion appears to me inevitable, that these variations are not due to the solar heat. We fortunately possess the means of deciding this question by the study of phenomena due to our satellite, whose heating action M. Faye has shown to be quite inappreciable. John Allan Broun {To be continued^ ^ I would remark here that the epoch of maximum range of foiice was not exactly the same as that for the maximum oscillation, a fact which may not be without importance when the mode of solar action is invesugateo. May 30, 1878] NATURE 129 THE MICROPHONE "IX /■£ have received the following communications on '' • this subject : — At a discussion upon Mr. William Preece' s paper on the microphone, which took place before the Society of Telegraph Engineers on Thursday last, the Duke of Argyll called attention to the important part which that invention was Ukely to play in physiological research. As chairman of the meeting I took occasion to refer to the intimate connection between the microphone and its two elder sisters, the telephone and the phonograph, in con- junction with which it formed a discovery which would probably be hereafter regarded as one of the greatest achievements in natural science of the present century. I ventured further to draw an anology between the action of the phonograph and the action of the brain in the exercise of memory, and with your permission I will enlarge upon this speculation to the extent of making my reasoning clear enough to submit the same to the critical test. All impressions received by us from without, either through the tympanum of the ear, the retina of the eye, or through the sensitive nerves of the skin, are, it is generally believed by physiologists, communicated to corpuscular bodies in the brain, which lie embedded in a grey substance, the nature and precise function of which have not yet been fully explained. It would appear that the corpuscular bodies in which the sensitive nerves ter- minate are connected, through the medium of extremely delicate filaments, with the nervous system of volition, the reaction of the one system upon the other being attributable to mental energy. It may be conceived that any fresh impressions received on the ex- tremely complex sensitive network of the brain may give rise then and there to acts of volition ; but how, it may be asked, can acts of volition arise from impressions that were communicated through the sensi- tive nerves yeai-s before, having been committed in the meantime to what we term the memory ? But in order that the mind can deal with an impression previously received it seems necessary" that it must have the power of reproducing the same from some material record by which the impression has been rendered permanent. Take the case of a tune that we have heard in early youth and which may not have since recurred to us. By some incident or other that tune and the words connected with it become suddenly revivified in the mind, If the tune had been sung into a phono- graph it could have been reproduced at any time by releasing a spring moving the barrel of the instrument ; and it seems a fair question to ask whether the grey substance of the brain may not, after all, be something analogous to a storehouse of phonographic impressions representing the accumulated treasure of our knowledge and experience, to be called into requisition by the directing power of the mind in turning on, as it were, one barrel or another. Such a hypothesis might possibly serve also to explain how in sleep, when the directing power of the mind is not active, a local disturbance in the nervous system may turn on one or more phonographic barrels at a time, and thus produce the confused images of dreamland ! A powerful mind would exercise a complete control over the innumerable barrels constituting our store of knowledge, whereas in a weak mind the impressions of the past would be brought back into evidence in a confused and irregular manner. Such a supposition might also account for the more vivid recollection of impressions received in early life, when the mechanical record stored up in the brain may be supposed to have been more distinctly and indelibly rendered. In speaking of these impressions as phonographic it does not follow that they were origi- nally conveyed through the tympanum of the ear. Mr. Willoughby Smith, at the meeting above referred to, called attention to the fact that, by substituting crystal- line selenium for carbon in the microphone, a ray of sunlight directed upon the selenium produces a noise comparable with that produced by a Nasmyth hammer; and it is quite feasible that the impressions received through the retina of the eye, and the nervous system generally, would be equally susceptible of being recorded in the cerebral storehouse. The record itself might be supposed to be of a mechanical, or, more probably, of a molecular character, the one thing important being that it must be material. These observations are, no doubt, extremely crude, but may serve possibly to direct the attention of physio- logists to a point of interest to their science ; nor would it be the first occasion on which a phenomenon of in- animate nature had revealed the secrets of animate organisation. C. William Siemens I HAVE been much interested in your account of the microphone of Prof. Hughes, and I have made, as doubt- less many of your readers have also done, the different forms of instrument described by him. The action of the instrument is there apparently attributed to the change of conductivity of the charcoal or carbon or of the mercury globules therein, under the influence of sonorous waves ; and whether this is correct is a question worthy of consi- deration in your columns, and I therefore write more for the purpose of leading others into the inquiry than of making assertions on the subject. My experiments point to another cause, viz., the variation of conducting sec- tional area of a bad conductor due to the increased or diminished pressure on the point of contact. I am not, of course, referring to the action of the instrument when the vibration is sufficient to absolutely sever the contact, which simply causes the telephone plate to vibrate either in its own period, or some other than that due to the acting sound, as is the case when a musical box is placed on the same table with the instrument ; but to the forced or articulate vibrations— the reproduction of the sound acting on the microphone. Of the several forms of instrument described by Prof. Hughes I have chiefly used that consisting of a rod of charcoal pointed at both ends, supported in a vertical position with its lower point resting in a hollow in a similar piece of charcoal, while its upper end rests against the sides of a similar hollow above. This form is extremely sensitive, and it is difficult to prevent the circuit being broken while having it sufficiently near the source of sound to be reproduced; the sound of a musical box is perfectly rendered, when so far away that there is an absence of jarring from breaks in the circuit ; but in talking to the instrument, any rise in the voice breaks contact and produces the jarring sound in the telephone, to the exclusion of all articulation. I find that any sort of charcoal or carbon will answer, whether soaked with mercury or not ; I therefore con- clude that the mercury has little or nothing to do with the action. I have tried the effect of sound on rods of carbon and charcoal both saturated with mercury and not so saturated, so arranged that the vibrations could not alter the area of contact, and have obtained no sound whatever from the telephone in the circuit ; I therefore conclude that the action takes place at the point or points of contact, and is due to the change of conducting area. To Prof. Hughes is due the credit of inventmg a means of varying the electric current with extreme rapidity and slight motion without absolutely breaking the circuit, but I doubt whether a microphone is a proper term for describing the instrument. In gently brushing the stand of the instrument, sound is heard in the tele- phone, but it does not at all follow that what we hear is a magnified reproduction of the brushing sound ; for if the rapidity of the vibrations or motion produced by I30 NATURE \May 30, 1878 brushing is insufficient to produce sound, still they may move the charcoal sufficiently to produce alternations of current, each of which may be able to set up vibrations in the telephone plate in its own period, or a modification of it, giving what I call the jarring sound. If, therefore, we have this sound, we know that either the microphone is exposed to sounds so loud as to produce complete break of contact, or that there is a motion going on affecting it, of insufficient rapidity to be audible. With the object of reproducing the voice or musical notes, I have made the following modification of the instru- ment : — A ferrotype plate 3 inches in diameter is fastened over a hole z\ inches in diameter in a thick piece of wood ; a flat piece of gas carbon weighing a few grains and having a fine copper wire attached to it is fastened to the top of the plate in the centre ; over the piece of carbon is suspended by a wire spring another piece of carbon finely pointed, weighing about \ oz , and adjusted so as just to touch the carbon plate. The current is then led by the wires through the carbon point, and by careful adjustment of the latter almost any degree of sensitiveness can be attained. Whenever the sound becomes too loud the current is broken, and minute sparks are seen at the carbon point, and the jarring sound is heard at thd same time in the telephone. The sound of a musical box is perfectly reproduced when the box is held in the air ; the instrument is therefore sensible to sound-waves in air as in solids. Geo. M. Seabroke Rugby I SEND an account of an experiment with the micro- phone which may interest some of your readers. A microphone, made of three pieces of gas carbon (as described by Prof. Hughes) and the primary wire of a Du Bois Reymond's induction-coil, are placed in the circuit of a single Daniell cell. The Avires from the secondary coil (pushed home) are attached to the poles of a Lippmann's capillary electrometer. The Daniell and microphone are twenty-five feet distant from the electrometer. If an observer watches the capillary- tube and speaks or sings to the microphone {which is twenty-Jive feet distant) definite and large movements of the mercury-column will be seen. The movements for various letters resemble those which have been pre- viously observed to take place with the telephone, the "w" giving its curious double movement. F. J. M. Page Physiological Laboratory, University College, London EARTHQUAKE IN VENEZUELA T N the evening of the 12th of this month a severe earth- ■■■ quake destroyed the town of Cua, in this country. Cua is situated on the left bank of the River Tuy, in 10° 8' 15" L. N. and 66° 55' W., Green w. The height over the level of the Caribbean Sea I found in 1873, by barometrical measurement, 232 metres. It was the centre of a very flourishing agricultural district (annual produce, about 80,000/. a year), and had about 3,000 inhabitants. The weather had been for weeks exceedingly hot, as generally this year in Venezuela. At 5 o'clock in the afternoon, before the earthquake, a temperature of 100° is said to have been noticed, and six days later, at the same hour, I observed myself 95°. The sky was clear, and the moon in perfect brightness. The shock occurred some minutes before a quarter to nine o'clock, and so violent was it that in less than two seconds all the centre of the town was a heap of ruins. It is impossible to fix the exact time of the shock, but it was felt in Cardcas at 8h. 41m. 34s., the distance in a straight line between both places being about twenty-six English miles. The centre of the town was situated on a small hill, about 20 metres over the lower part. The hill is com- posed of gneiss, micaceous and chloritic schists, rising rather steep towards W.S.W. This hill is surrounded by strata of clay and marl, covered by a deep stratum of alluvial soil, and resting on dark limestone and argil- laceous schists, containing numerous crystals of iron pyrites. Only the upper town was laid waste ; the lower part suffered comparatively very little. From actual observa- tions I found that the angle of emergence of the shock was about 60°. The centre cannot have been very deep, as the destruction was limited to a spot measuring only one square mile, although the shock of the transverse wave was felt in places 100 miles distant. The soil had burst at different places, giving issue to water highly im- pregnated with sulphuretted hydrogen. The shocks con- tinued for several days, and are not yet entirely gone, but no further damage has been caused. About 300 people were killed ; the loss of property is said to be about 300,000/. sterling. I have reason to think that this earthquake had nothing to do with volcanic forces, but was due to an interior sub- sidence or downfall of calcareous rock, as I intend to prove in a special memoir on this subject, as soon as I shall have visited the locality once more. Caracas, April 30 A. Ernst OUR ASTRONOMICAL COLUMN Tempel's Comet, 1873, II. — We continue the ephe- meris of this comet, for the latter half of June, as given by M. Schulhof in the Paris Bulletin International of May 7. If the calculated epoch of perihelion passage be approximately correct, the intensity of light will be increasing, and the comet would arrive at its least distance from the earth early in July. But the possible error in the mean motion determined from the observa- tions of 1873, may render a search over a wide extent of sky unavoidable, if the comet is to be recovered at the present return. Shortly before the completion of his calculations M. Schulhof informed the writer that the probable error in the mean daily motion would not exceed ± 7", but this degree of uncertainty involves a difference of nearly ± 20 days in the date of perihelion passage, so that the comet may be found after close search in a position considerably distant from the computed one. As in other similar cases, if the observer has the command of an equatorially-mounted instrument of good aperture, the most promising plan of search will be to commence at the calculated declination for the day, extending the sweep to 30m. or 40m. on each side of the calculated R.A., and to continue the same proceeding for 3° or 4° on each side of the calculated declination. It may be re- marked that the computed R.A. for a certain change in perihelion passage, varies more rapidly than the com- puted declination. Perhaps there is a greater proba- bility of the comet being detected at the latter end of June than subsequently, if the weather is generally favourable for a careful search. The following positions for Paris midnight are deduced on the assumption that the comet will arrive at perihelion Sept. 1*5, the most probable date : — T,- T,., » • N. Declina- Distance from Intensity Right Ascension. j;^„_ ^^^^ of light, h. m. s. , / June 15 ... 15 34 44 ... 5 6 ... 0-667 ... 0-90 „ 19 ... IS 32 15 ... 4 17 ... 0-659 ••• o'9S „ 23 ... 15 30 20 ... 3 20 ... 0-654 ••• o"99 „ 27 ... 15 29 5 ... 2 15 ... 0-651 ... 1-05 July I ... 15 28 31 ... I I ... 0-649 ... 1-06 The RECENT Transit of Mercury.— In the instruc- tions for observing this phenomenon suggested by Prof. Newcomb, and circulated by the United States Naval Observatory, it is remarked that "its accurate observation is of especial importance as affording data i7/«y 30,1878] NATURE 131 which will be decisive of the question whether the result of Leverrier, that the motion of the perihelion of Mercury is much greater than that due to the action of the known planets, is really correct." So far as the results of obser- vation have been made known, there is every indication that the theory of Leverrier will receive a striking con- firmation therefrom. The observations of first internal contact in Europe are closely accordant with calculation ; and in a telegram from M. Andrd, in charge of the French expedition, despatched through the liberality of M. Bischoffsheim to Ogden, in the Utah territory, for the observation of the transit, it is stated — " sortie con- firme theorie." Adopting Leverrier' s diameters of sun and planet, deduced from his elaborate discussion of the transits of Mercury observed to 1832, and the value of solar paral- lax determined by Professor Newcomb (8" '848), we have the following equations for the reduction of observed times of first external and internal contacts to the centre of the earth : — h. m. s. s. s. o . / First ext. cont. ...3 13 i-o + 74'S3, p sin / + 80-89, p cos /, cos (L-56 49-3) First int. cont. ...3 16 8-4 + 74*92, p sin / + 81-32, p cos /, cos (L-56 2-4) Where / is the geocentric latitude, which may be ob- tained together with p, the radius of earth at the point of observation, from Bessel's Tables in the Berliner astro- nomisches Jahrbuch for 1853, and L is the longitude from Greenwich counted towards the east : the resulting times are for Greenwich. We shall give next week a comparison between observation and calculation. Encke's Comet.— The Filrstl Jablo7iowskVschen Cesellschaft oi Leipsic have offered a prize in 1881 for a new investigation on the motion of this body, their former similar offer for 1877 not having met with a response. It is urged that the researches of Dr. von Asten, so far as they are known, have not led to any definite result, and other periodical comets not having shown any indications of a resisting action such as is apparent in the motion of Encke's comet, a further complete and separate investi- gation (z/£»//y/a:>/<^i!^^iV,?«(5^rt'r^^//««^) is much to be de'sired. Accordingly the Society's prize of 700 mark is again offered. It is stipulated that all known perturbing forces are to be taken into account, and the calculation is at least to include the period from 1848 to the last appearance of the comet. A similar work for the earlier portion of the interval elapsed since the first discovery in 1786, is reserved as the subject for a future prize. In connection with the anomalous motion of Encke' s comet it may be remarked that Brorsen' s comet of short period appears deserving of much closer computation than it has yet received. After that of Encke's comet its perihelion distance is considerably less than in the case of any of the other comets forming this particular group, as the following statement will show. Biela's and De Vico's comets are omitted : — Perihelion Distance of Encke's Comet 0*333 „ I, Brorsen's 0-595 M )> Winnecke's 0781 »> >, D'Arrest's 1*280 .» » Tempel's (1873, H.) ... 1-339 ,, >. Faye's 1-687 » .» Tempel's 1867, II.) ... 1-769 GEOGRAPHICAL NOTES The Anniversary Meeting of the Geographical Society on Monday was not marked by any unusual feature. The address of the president— his retiring one, as it turns out— consisted as usual of a comprehensive review of the geographical work of the past year, an unusually event- ful one in exploration. The Society is as prosperous as ever in members and money. There were on April 30 3,334 Fellows on the register, of whom no less than 762 are life members On the motion of Sir Henry Rawlin- .5on, the meeting adopted an alteration of the rule regu- lating admission to meetings of exceptional interest, with a view to obviate certain difficulties which have arisen in this respect. The Royal Medals, the award of which we have already announced, were presented to Count Miinster, the German ambassador, on behalf of Baron F. von Richthofen, the President of the German Geographical Society, and to Capt. H. Trotter, R.E., personally. The schools' prize medals were also presented to the success- ful competitors whose names we have before recorded. From the new president. Lord Dufferin, we may next year expect an address marked by unusual raciness, eloquence, and intelligence ; Lord Dufferin will probably return to this country in autumn. The Committee of the African Exploration Fund of the Royal Geographical Society have at length definitely resolved to despatch a carefully organised expedition to explore the unknown tract of country lying between the caravan road which, as we have before mentioned, is being constructed from Dar-es-Salaam (a few miles south of Zanzibar), to the northern end of Lake Nyassa. Mr. Keith Johnston will, we believe, be in command, and, will be accompanied by another European not yet selected. Should this expedition prove successful, and, what is equally important, sufficient funds be forth- coming, the committee contemplate pushing their explo- rations to the southern end of Lake Tanganyika, a further distance of 190 miles, thus completing approximately two of the routes sketched out in the circular issued last summer. In order to enable the committee to despatch this expedition, which is expected to furnish important and valuable geographical information, the Council of the Geographical Society have just made a further grant of 500/. to the fund, and it is hoped that the public and the subscribers will lend it such additional support as will be required to carry out the objects in view. At the last meeting of the Geographical Society of Paris M. de Lesseps stated that Col. Gordon had pushed the Egyptian advanced posts up to the equator, and that now any traveller can go from Paris to the equator within sixty days if he has procured a letter of introduction from M. de Lesseps, Abbd Debaize, who, as we have already stated, intends to cross Africa, has availed himself of this privilege and is probably now on the banks of the Albert Nyanza. M. de Lesseps states, moreover, that the num- ber of lakes is greater than was supposed after Stanley's mission, and Col. Gordon is making a careful survey of the newly Egyptianised country. He has sent to M. Daubr€e, Director of the School of Mines, some speci- mens of gold and silver ores brought from the interior, in order to ascertain their value. The Society has re- cently received a detailed account of the expedition made by MM. Cambier and Marno from Zanzibar during the past winter. The journey lasted seven weeks, and was accomplished without loss of life. The chief object of this tour was to test the availability of the route by Mpwapwa for expeditions into the interior of Equa- torial Africa. It was found to be well adapted even for waggons. The Italian Consul at Aden, who is now in Europe, is occupied with the formation of a society for the purpose of acquiring a portion of land and forming an Italian colony at Shoa. The object of the colony is to establish commercial relations between Italy and Central Africa. The African traveller, Carlo Piaggia, is now making the final preparations for a new journey to Equa- torial Africa. This journey will be his fourth ; formerly he has principally visited Abyssraia and Soudan. Mr. Gordon Bennett's polar expedition, to which we have already referred, is not to start, it would seem, till 1879, "when, in June, it will probably leave San Fran- cisco for the route by Behring' s Straits. The Pandora, which will be re-christened the Jeannette, is being thoroughly refitted in Walker's yards on the Thames. 132 NATURE [May 30, 1878 NOTES The Haarlem Society of Sciences resolved, some years ago, to award, biennially, a medal to the individual who, by his researches, discoveries, or inventions, during the previous twenty years, had, in the judgment of the society, distinguished himself in an exceptional manner in a particular branch of science. This year the medal was to be devoted to astronomy, and on the i8th inst. was awarded to Prof. Simon Newcomb, We believe the medal would have been awarded to Sir George Airy if the committee had felt themselves at liberty to embrace a period greater than twenty years past ; but, according to the rules regulating the award, they are rigidly confined to the period stated, Mr. Carl Bock, F.G.S., who has had considerable experi- ence in the collection of shells and other specimens of natural history, is leaving England at the end of this week for Padang, in Sumatra, in order to explore and collect in the highlands of the interior of the island. Recent advices from Auckland state that Signor Beccari and Capt. D'Albertis, a nephew of the New Guinea explorer, were visiting the colony on their way to Europe, and that Signor Beccari had with him some 12,000 specimens of the flora and fauna of New Guinea. If Mr. Herbert Spencer remembers his Bible, an oft-quoted passage must have occurred tcf him on Sunday (appropriately) — " A prophet is not without honour save in his own country and among his o^vn people." On that day, in Paris, where he has been spending a few days, a semi-public dinner was given to the English philosopher by a number of his admirers, headed by the well-known publisher M. Germer-Bailliere. Mr. Spencer, in replying to the toast of his health — and he actually replied to a toast, and that too in a style not much out of the common — ^hinted that he was better known and better appre- ciated in France than in England, where, so far as we know, he never appeared either on a public or semi -public occasion. A decidedly social evening seems to have been passed by the assembled savants, Mr. Spencer concluding his genial and com- plimentary reply by drinking to the peculiarly French senti- timent — Brotherhood [h la fraternity). M. Bardoux has written to the Meteorological Society of France asking them to organise the congress of meteo- rology. The committee of this ^association have written to the Association Scientifique of France, and other societies, requesting them to appoint a number of their members to serve on the committee of organisation. The aeronauts are not pleased because no invitation has been directed to any of the aeronautical societies of Paris. Notwithstanding that M. Bardoux has published his decree on the meteorological organisation of France the great commission has held no sitting, and the list of presentations for the successor to M. Leverrier has not yet been deliberated upon. This singular delay is preventing the government from taking any step towards the realisation of the newly-established meteorological institution. The "Associations" are waking up once more and beginning to warn all whom it may concern to be ready for the great annual autumnal talk. So far as the British Association ;^is concerned it has confined itself as yet to the usual preliminary advertise- ment and the private invitation circular intimating that this will be an Irish year — and no doubt Dublin will give a thoroughly Irish welcome — that the opening day is August 14, and that Dr. W. Spottiswoode is the President-Elect. Our Ameri. can friends in this, as in some other things, are ahead of us, for already we have received the printed circular of arrange- tnents for the twenty-seventh meeting of their Association, which is to be opened at St. Louis a week after our own, on August 21, with Prof. O. C. Marsh as President. Any English men of science who are likely to be in the States aboiit the time of the meeting and who would like to be present, should write to Prof. F. W. Putnam, Salem, Mass,, the Permanent Secretary, who, we are sure, will gladly give all necessary information. It is stated on good authority that the Water and Woods Department of the French Exhibition will be preserved as a permanent museum, and re-erected in the Bois de Boulogne after the close of the Exhibition, All the specimens of woods exhibited by foreign nations will be purchased if not presented by their respective departments, and added to the intended museum. All the parts of the central building have been constructed so that they can be utilised for railway stations, large markets, &c., and will be sold accordingly. It is stated that the greater part has been already disposed of. We see that parliament has also authorised the purchase of suitable apparatus for the Conservatoire des Arts et Metiers. Although intended originally only to last up to October it is pretty certain the Exhibition will not close before November, according to the universal wish expressed by exhibitors and public. With the month of June will be commenced the visits to the Exhibition of the pupils of the several municipal schools of Paris, under the guidance of their teachers, with free tickets given by the Government in accordance with the votes of the Chamber of Deputies. A SINGULAR blunder for a city that has established an official committee on lightning conductors has been committed by the architect of the Paris Exhibition ; iron conductors have been placed on the central building which is in solid iron. This extraordinary error was also committed in 1867, It shows how little the principles enunciated by Franklin are understood even by scientific people. Giffard's captive balloon is almost ready ; the two steam- engines, 150 horse-power each, for working the monster cylinder, will be tried next week. The cylinder, which weighs 49,000 kilograms, has a length of 12 m. and a diameter of 175 ctm. ; it will revolve with a velocity of 30 turns per minute. The exact weight of the rope is 1,950 kilos, for a length of 600 m. It has been made at Angers in less than a week, and will be tried within a few days. Next week the apparatus for manu- facturing hydrogen gas at a rate of 1,000 cubic m. per hour will be completed. The varnishing of the monster balloon began on Monday ; the preliminary ascents and police inspec- tion will take place from June 10 to 20, and the balloon is expected to be opened on the 22nd. The expense will probably exceed ;^20,ooo. The portrait of Harvey, which we give this week, properly belongs to the previous volume, and ought to be bound along with it. Prof. Huxley's notice of Harvey will be found at p. 417 of that volume. The Sydney Mail of March 30, we learn from T/ie Colonies, con- tains a letter from a Mr. Severn, dated Newcastle (New South Wales), March 24, in which he gives details of a singular discovery he has made, whereby deaf people can be made to hear by means of the telephone. After describing a very simple telephone which he constructed out of a tin pot, the closed end of which he opened and tied over it a piece of parchment, passing a fine string through the centre and making a knot inside, he says : — "Make a loop in the string some three feet long, put this loop over the forehead of the listener (the deaf man), cause him to place the palms of his hands flat and hard against the ears, let the loop pass over the hands, and now this listener will hear the smallest whisper, let him be deaf or not. This fact may appear extraordinary ; it is, nevertheless, true that a deaf man may 3Iay 30, 1878] NATURE ^2>Z thus be made to hear the voice, music," &c. A diagram is pub- lished in the Mail, showing the working of the telephone as described. The cultivation of the opium poppy {Papaver somniftntni), which has hitherto been exclusively confined to the east, bids fair to become thoroughly established and remunerative in Eastern Africa. Seeds of the best kinds have been imported from Malwa into Mozambique, where 50,000 acres of uncultivated State land have been granted to a company, with a capital of 178,000/., for the purpose of cultivating and trading in opium. Besides the grant of land, the company also receives from the State " the exclusive right for twelve years to export opium free of duty through all the custom-houses of the province." It is satisfactory to learn that the poppy plants are thriving, and the fruits are reported to be larger than those produced in the best opium districts of India. A Russian medical paper draws attention to Sarracenia pur- purea as a remedy for gout, administered in the form of a powder in the proportion of one or two teaspoonfuls morning and evening. The thirty-second meeting of German philologists and peda- gogues will take place at Gera at the end of September. Herr Ferdinand Noll, of Brandenburg, has presented to the International Postal Congress, now sitting at Paris, the drawings and descriptive -plans of a decimal clock as well as two models of the clock itself. Its object, as its name implies is to introduce a division of time on the decimal system in accordance with that already in use for measures, weights, and moneys. Herr Noll therefore divides his dials into twenty hours and gives 100 minutes to the hour, each minute having fifty seconds, and each second fifty "tertien." Dr. Forster, the Director of the Berlin Observatory, gave a very favourable opinion of the inven- tion when submitted to him two or three years since. A French agricultural paper announces the discovery of an extremely simple and cheap means to protect houses from being struck by lightning. This consists merely in bundles of straw attached to sticks or broom-handles and placed on the roofs of houses in an upright position. The first trials of this simple apparatus were made at Tarbes (Hautes Pyrenees) by some intel- ligent agriculturists, and the results were so satisfactory that soon afterwards eighteen communes of the Tarbes district pro- vided all their houses with these bundles of straw, and there have been no accidents from lightning since in the district. The Emperor of Austria has conferred the Cross of the Order of Francis Joseph upon the two well-known African travellers, Drs. Georg Schweinfurth and Gerhard Rohlfs. The large botanical library left by the late Prof. A. Braun, formerly director of the Berlin Botanical Gardens, is now being sold by Messrs. List and Francke, of Leipzig. Our readers will be glad to learn that Sir William Thomson and Prof. Tait have nearly completed for publication the first part of the new edition of their ^work on natural philosophy, which will be brought out very shortly by the Cambridge University Press. No less than twelve separate subterranean shocks are re- ported from Ancona as having occurred between May 9 and 12. The Government of Uruguay intends to construct a railway which will unite Uruguay with the Province of Rio Grande do Sul, in which many thousands of colonists are settled. The line is to begin on the right bank of the Quarahim River, and is to extend as far as the town of Uruguayana. On the Quarahim River this railway will join the line in course of construction between Salto and Santa Rosa, which is already finished and in use as far as Jacuhi (some 300 miles), and which in turn corre- sponds with the line between Salto and Fray Bentos, where the great Saladeros (slaughter-houses) of the " Liebig Company " are situated, at which over 1,000 head of cattle are killed daily to make the well-known "Liebig Extract of Meat." Mr. J. M. Wilson, of Rugby, has in the press a treatise on geometry written to correspond with the Syllabus of the Geo metrical Association. The work will be published by Messrs. Macmillan and Co. Messrs. Macmillan and Co. are preparing for publication a treatise on the nature and origin of coal and the extent of the supply in this country, written by the Professors of the Yorkshire College of Science, Leeds. The authors propose to sketch out the state of the country at the time when coal was coming into being and the processes by which it was formed ; next to deal with the present, and give an account of the methods of working coal and some of the uses to which it is now being put ; lastly, to endeavour to forecast the future and speak of the probable duration of oiu- coal supply. The work will be edited by Prof. T. E. Thorpe, F.R.S. In it Prof. Riicker will treat the subject from the physicist's point of view ; Prof. Miall will discuss its natural history ; Prof. Green will take the geology of the question ; Prof. Thorpe the chemistry ; and Prof. Marshall will write on the economics of coal. In a recent paper in VAeronaute, Col. Laussedat gives the results of experiments made by a Commission appointed by the French Minister of War. For Captive Balloons it is absolutely necessary to employ the best silk and cordage, which, with the least weight, offers the greatest guarantee of durability. After much research a special varnish has been found which renders the aerostat impermeable to gas. Instead of numerous ropes held by men as in former military ballooning, a single cable has been adopted to work by a simple but secure capstan. Capt. Renard has discovered a rapid and economical new process of manufacturing hydrogen. For Postal Balloons Capt. Renard also has devised a secure and easily-worked valve. A liquid instead of a solid ballast has been resolved on, and a fluid is being sought which will not congeal in the low temperatures of the upper atmosphere. The valve and the ballast may work automatically and maintain the balloon at any given height. Among the methods of stopping the balloon experimented on are the javelin anchor of Meusnier and a sort of iron arrow devised by Capt. De la Haye. For Directable Balloons the principles which guided Dupuy de Lome have, for the most part, been adopted by the Commission. That experimenter found that with an engine of eight horse-power turning a screw he could deviate from the direction of the wind by a considerable angle, with ordinary winds, and even travel, with reference to the earth, in all directions which it would be wished to follow. The Commission, however, instead of placing the screw in the car, at a great distance from the point of application of resist- ance of the air, have constructed the balloon so that the screw may work in the very centre of the aerostat. Those familiar with the treasures of the Biblioth^que Na- tionale in Paris will appreciate the importance of a law lately laid before the French Chamber by the Minister of Public Instruction, providing for the demolition of all buildings adjoining the library, in order to insure its complete protection from danger by fire. The great building will in the future be entirely surrounded by an open space laid out in gardens and walks. The Paris Jardin d'Acclimatation has just received from the Seychelles Islands three of the largest tortoises known. The heaviest weighs 187 kilogrammes and is ij metre in diameter. At the meeting of the Institution of Surveyors on the 13th May, Mr. R. W. Peregrine Birch read an important paper on the use of sewage by farmers. Mr. Birch has collected a considerable quantity of statistics on this unsavoury but im. portant subject, firom which the following conclusions are 134 NATO RE \May 30, 1878 drawn : — 1st. That there are upwards of 100 owners and occu- piers of land in Great Britain who use sewage for the sake alone of what they can get out of it by agricultural means, 2nd. That of this number more than sixty are tenant farmers who continue to use it although they have, annually at least, the option of ceasing to do so. 3rd. That of the latter number about five-sixths, and of the total number about three-fourths, actually pay money for the use of the sewage, either in the form of out-fall rent, unquestionable increase of land rent, or the price of occasional dressings. Nearly 4,000 acres of sewage land have been referred to, and these are in the hands of more than a hundred distinct occupiers. These occupiers may be divided into three classes : — Those who have to cleanse a certain quantity of sewage on a certain area of land ; those who may take, or leave alone, as much of a town's sewage as they please ; and those who may take, or leave alone, what sewage can be spared by others having a prior right. The first class occupies 1,670 acres of sewaged land, and deals with the sewage of twenty distinct sanitary districts, or a population of about 200,000 on as many as twenty-one different farms. Mr. Birch's paper will be published as a pamphlet by Messrs. Spon. Among the novelties in the German book trade for May, we notice the following scientific works : — " Teleologie und Dar- winismus," Dr. Kalischer (Berlin) ; " Gedanken iiber die Teleo- logie in der Natur," v. Barenbach (Berlin) ; " Reisebriefe aus Kordofan und Dar-Fur," Dr. F. Pfund (Hamburg); "Die allgemeinsten chemischen Formeln," Prof. C. Willgerodt (Hei- delberg) ; " Der Sternhaufen x Persei, beobachtet in der Leip- ziger Sternwarte von 1867-70," H. C. Vogel (Leipzig) ; "Die Verbreitung der Atmosphare," M. Thiesen (Berlin) ; " Aus der Physik des Luftmeers," G. Miinter (Herford) ; "Praxis der Naturgeschichte botanische, zoologische, und Akklimatisations- garten, Aquarien, &c.," P. L. Martin (Weimar); "Atlas coelestis eclipticus viii.," E. Heis (Cologne) ; " Die Fauna des Graptolithen-Gesteines," K. Haupt (Gorlitz) ; "Bericht Uber die Beobachtung des Venus-Durchgangs vom 8ten December in Luxor," A. Auwers (Berlin) ; " Theorie der Warme," translated from Prof . J. C. Maxwell by F. Neesen ; "Das Nervensystem &c., der Medusen," O. and R. Hertwig (Leipzig);; "Journal des Museums Godeffroy — A. Garret's Fische der Siidsee " (Hamburg); "Fungi italici authographice delineati," P. A. Saccardo (Berlin). The three last are very expensive works. The additions to the Zoological Society's Gardens during the past week include three Common Rheas (_Rhea americana) from South America, presented by ^ Mr. Frank Parish; four Water Ouzels {Cinclus aquatiais), British, presented by Mr. R, J, L. Price ; a Hairy Tapir {Tapirus roulint) from Columbia, two Great-Billed Rheas {^Rhea macrorhyncha), two Sulphury Tyrants (Pilangus sulphuratus) from' South America, received in ex- change ; two Chimpanzees ( Troglodytes niger) from West Africa, deposited ; two Bar -headed Geese {Anser tttuicus) from India, purchased ; a Great Kangaroo {Macropus giganteus), two Wild Boars {Sus scrofa), two Wild Cats (Felis catus), born in the Gardens ; two Geoffroy's Doves {Peristera geoffroii), seven Chilian Pintails {Dafila spinkauda), a Yellow-Legged Herring Gull {Larus leiicophoeus), bred in the Gardens. THE FRENCH METEOROLOGICAL SERVICE "XXTE learn that M. Mascart has been appointed head of the meteorological bureau. He is professor in the College de France, his special subjects being light and electricity. He is author of a work in two volumes, on static electricity. Last week we gave a brief sketch of the new organisation of_ the French meteorological service by the government, and this week we are able to publish a translation of the decree, from which it will be seen how much alive the French govern- ment is to the national importance of a complete meteoro- logical service. How Article 2, referring to "Titular Meteoro- logists," "Adjoint Meteorologists," and "Assistant Meteoro- logists," must surprise our "Meteorological" Council! In France they actually insist upon meteorologists to do meteoro- logicaVwork and to advise upon meteorological matters. Article i. — The meteorological division of the Paris Obser- vatory forms a distinct service, which takes the title of " Bureau Central Meteorologique." This service comprises the study of the movements of the atmosphere, meteorological advertise- ments to the ports and to agriculture, the organisation of the meteorological observations, and of the regional or depart- mental commissions, the publication of their works, and the whole of the researches on meteorology or on climatology. 2. The meteorological service of France comprises titular meteorologists, adjoint meteorologists, and assistant meteoro- logists. The salary of the titular meteorologists varies from 3,000 to 10,000 francs. The 7 THURSDAY, JUNE 6, i( MODERN NAVAL ARCHITECTURE A Manual of Naval Architecture. For the Use of Officers of the Royal Navy, Officers of the Mercantile Marine, Shipbuilders, and Shipowners. By W. H. White, Assistant Constructor, Royal Navy, &c. (London: John Murray, 1877.) NO one acquainted with our own and foreign navies can doubt that at the time of the establishment of the Royal Naval College at Greenwich Great Britain had been falling very much astern of other countries in the professional education of its naval officers. In the days when ships were all pretty much alike, and differed chiefly in forms and proportions, the greater progress of other navies in technical science was, perhaps, of no great moment; but in days like -the present, when the sea teems with experimental ships flying the royal and mercantile flags of this country, the neglect of known principles, or the failure to discover others, may have the worst results. It was for this reason, among others, that the writer of these remarks long since joined those who pressed for the establishment of a Naval College worthy of the country and of the time, and it was doubtless for this reason also that the Government of the day — and more especially Mr. Goschen, then First Lord of the Admiralty — founded the great Naval Institution which now flourishes at Greenwich. It is there that Mr. White, the author of the work before us, has been engaged in expounding naval architecture to naval officers and other students, and it was in the performance of that important duty that he felt the need of such a work pressed upon him. Mr. White is himself, in no small degree, the product of previous acts of wisdom on the part of Boards of Admiralty; and as those Boards very often come under just censure for their errors and omissions, it is a pleasure to be able sometimes to record their wise and enlightened doings. Mr. White was a distinguished student (and afterwards a Fellow) of that Royal School of Naval Architecture at South Kensington which Lord Hampton took so much pains in promoting, and which the Ad- miralty founded ; having been elected to a studentship at a competitive examination in a Royal Dockyard School, where he had previously undergone a good and extensive grounding in elementary, and indeed in more than elementary, science. It is gratifying to know that Mr. White, like all the naval architects of high position at present in the Admiralty, thus represents a successful system of Government training, commencing in the Royal Dockyard Schools, and advancing through higher- class royal schools, to the most eminent spheres of professional influence. The object of the present work is to supply to naval officers, and to such others as may need or desire it, a statement of the general principles which underlie the profession and practice of.' the naval architect. With- out some clear and definite knowledge of these principles it is not possible for naval officers to apply modern vessels to their designed services with skill and success. The loss of the Captain and the foundering of Vor,. xvni. — Xo. .%•/) the Vanguard afforded dramatic examples of the class of disasters which may be expected to result and must result from the imperfect handling of modern vessels ; and if all the facts of the case could be known, the loss of the Eurydice would probably be brought more or less within the same category. In the case of the Captain notwithstanding the grievous well-known defects of her design, the laws which regulate a ship's stability and power to carry canvas if known to and applied by those in command of her, would have suggested the paramount necessity of shortening sail in the wind which capsized her; and the evidence taken after the sinking of the Van- guard points clearly to the fact that the prompt closing of certain water-tight doors, and other like measures wQuld, in all probability, have saved the ship, or at least have given her ample time for reaching shallow water. As regards the Eurydice it is well-known that she was an experimental vessel, designed by a naval officer many years ago, and that some not very usual features tending to reduction of stability entered into her form. It is obvious that in all such cases — and indeed in the cases of all ships — a knowledge of the principles which enter into their construction and use should, as far as possible, be communicated to those upon whom is placed the respon- sibility of employing them under all the varying con- ditions of sea-service ; and this not merely for the purpose of secu -.ng their safety, but also with a view to their efficient and economical employment. Only the few persons who have had special opportunities of observing the facts can imagine the extent to which the performances of ships in steaming, in sailing, and in other operations, depend upon the knowledge and skill of those who command and work them. It is not too much to say that, as regards vessels which in the main resemble each other, the differences in the officers who command them usually obliterate altogether the distinctive qualities of the vessels themselves, and the relative skill of their designers. To the readers o Nature it is doubtless needless to dwell upon the de- sirability of the naval officer, whether of the royal or the mercantile marine, possessing the knowledge of ships, and of naval principles, which Mr. White's work is designed to convey. In composing this work the author has shown himself most judicious in determining the limit beyond which it would not be well to carry theoretical investigation in addressing naval officers. In each of those chapters in which a temptation to over-indulgence in this respect would most be felt by a man highly trained in the theory of naval architecture, the self-restraint of the author is obvious, and deserves all praise. The book is readable throughout by all naval officers who have availed them- selves with energy and spirit of the educational advan- tages which the royal navy now affords to every officer, and it presents to them, for the first time, a sound, well- selected, and trustworthy summary of naval science such as was beginning to be most strongly felt in the merchant no less than in the royal navy. In his first chapter the author explains the buoyancy of ships, their subdivision into compartments, and the effect of admitting water into compartments variously placed, and discusses with clearness and with the latest infomia- tion the vexed question of freeboard. The accuracy and 138 NA TURE {June 6, 1878 perspicuity with which this chapter is written are remark- able, and prove the fitness of the author for the work he undertook. Diagrams are given wherever they would serve to assist the reader in readily apprehending the subject. The second chapter is devoted to tonnage measurement, and, while mainly derived from an article contributed by the author to Naval Science (a periodical which is no longer published), it embodies all that naval officers need know upon the subject, including the measurement of yachts, and the regulations of the Suez Canal ; these latter, we regret to say, are in some respects carried out at present in violation of the understandings which were come to with the British Government, and were announced as authoritative by our Ministers in Parliament. The third chapter is an admirable statement of the prin- ciples which regulate the statical stability of ships — a subject upon which Mr. White well deserves to be pro- nounced a high authority, and one who has worthily extended this branch of science.' This chapter, like some later ones, embodies information which the naval architect would do well to study, more especially as regards the effect upon stability of adding, shifting, and removing weights. At p. 63 the author remarks that the question of neutral or indifferent equilibrium has little practical interest in connection with ships, "for which stability and instability are alone important." However true this may have been a short time ago, it is no longer so, for the case of the Itiflexible has invested the question of infinitesimal stability, and of neutral equilibrium, with a strong and melancholy interest, and an interest which must go on increasing if such ships are repeated. The investigations of the Liflexibl^s state led the writer of these lines to observe and consider a peculiar condition of stability which may, and doubtless will, arise in citadel ships like the hiflexible, with unarmoured ends large in proportion to the citadel, and which would add a curious case to the numerous curves of stability v/ith which this chapter is illustrated. It is the case in which the citadel is so formed and proportioned, that the ship, with her ends penetrated, would have no stability in her upright position, but would acquire a small amount on inclining through a greater or less angle, and lose it again on being inclined still further. This case would exhibit itself in a curve of stability by a mere loop, of greater or less length and depth, and at greater or less distance from the origin, according to circumstances. A similar result would of course arise in any ordinary ship, the statical stability of which was nil in the upright position, but become positive at an inclination. We mention it here, however, because in the case of a citadel ship it reduces to an absurdity, and to Avorse than an absurdity, that reference to " range " of stability Avhich has been much too frequent in recent discussions. In a future edition Mr. White would do well to extend his remarks upon this branch of the subject, as it has become one of great practical, and even of vital interest. The following chapters, on the Oscillations of Ships in Still Water, on Deep-Sea Waves, the Oscillations of Ships among Waves, and Methods of Observing the Rolling andPitching Motions of Ships, together form a ' By a valuable paper " On the Calculations 'of the Stability of Ships," read at the Institution of Naval Architects in 1871, the joint production of Mr. White and Mr. W. John, now of Lloyd's Register Office, and by other contributions to the- knowledge of this subject. most valuable treatise on a branch of naval science which is both in form and substance essentially modern, and full both of interest and of future promise. Although this part of the work has necessarily been composed chiefly by compilation, it is the result of much labour, and of a close study of a large number of essays and discussions which have appeared from time to time during the last eighteen years. In the first paper ever read (in i860) at the Institution of Naval Architects, Dr. WooUey said — "One of the chief benefits to be looked for from the Institution which we are inaugurating to-day is a more systematic inquiry into the laws of nature on which the motions of a vessel at sea depend than has hitherto been attempted." These were prophetic words, for the field of labour to which scientific men were thus invited was very soon entered upon by Mr. Froude, who has most worthily and successfully laboured in it ever since. He has been joined by other labourers who have well and steadily advanced the good work, in- cluding several able French savans (notably M. Berlin, of Cherbourg, and M. Duhil de Benaz^), and most recently Dr. WooUey himself, who a month since con- tributed to the same institution a most able analytical discussion of the constitution and properties of deep-sea waves. No summary of the recent striking developments of science respecting the constitution of sea waves, and the behaviour of ships among them, which can at all com- pare with that here" given by Mr. White can anywhere be found. The following chapter on the strains experienced by ships is an equally clear and comprehensive statement of another thoroughly modern branch of study. It is primarily based upon a paper published in the Philo- sophical Transactions by the present writer in 1 871, in the calculations and construction of which Mr. White largely co-operated. The methods of investigation pur- sued were novel, and of so detailed a nature as to place the subject on a solid basis of fact, with the result of either setting aside or subverting most of the opinions — for they were but opinions — which had previously prevailed. The present author gives the substance of those labours, and adds to them the results of many others of more recent date, supplementing the general investigation with brief examinations of minor and local strains. The chapters on the structural strength of ships and materials for ship- building, although of less immediate value to naval officers than those that illustrate the behaviour of ships in motion, abound with facts which they will find of daily value afloat. In places the author is somewhat more historical and diffuse, perhaps, than is strictly consistent with the object of the work, but all that he records is valuable, and the narrative passages will doubtless add to its attractions, especially in the eyes of the younger officers. With re- spect to the important question of the "Resistance of •Ships " (so designated, as usual, although "Resistance to Ships ' ' would surely be more correct) the author has per- formed a like service to that rendered in the case of the recent discoveries respecting waves and the oscil- lations of ships. He has sketched and summarised the existing knowledge of the subject, and here as elsewhere has kept mere abstract considerations and theories well under the control of practical requirements. He has done justice to the recent labours of Mr. Froude in this sphere June 6, 1878] NATURE 139 of investigation likewise, and has shown how advan- tageous his experiments with models have been. The present Controller and Constructors of the Navy deserve great praise for giving their steady support and apprecia- tion to Mr. Froude in his experimental work. The remaining chapters of Mr. White's book are on Propulsion by Sails and by Steam, and on the Steering of Ships. While well and clearly written throughout, and embodying all the settled science of these questions, these chapters appear to us to be less firmly based in some respects, and to present more controversial matter than the earlier parts of the work. We are unable, for example, to approve of the strong preference expressed for the compound engine over other types of marine engine. Basing his views upon the actual performances of three separate types of engine — the ordinary old type of jet-condenser engine, the surface-condenser type, and the compound type — the author goes on to claim for the last-named enormous advantages. In making his com- parisons and drawing his inferences, however, he seems to us to generalise too freely, and to leave out of con- sideration many facts and circumstances which we are bound to consider before pronouncing in favour of the compound engine. Nor are we by any means alone in calling in question the pre-eminent merits of this form of engine when regarded in the light of general principles. Among others who have expressed similar views we may advert to Mr. Neil McDougall, himself an officer of the Admiralty (Steam Branch), who in 1875 published an essay on " The Relative Merits of Simple and Compound Engines as applied to Ships of War," and who arrived, after a long and patient investigation of the Admiralty and other records, at these conclusions, viz., " That there is no insuperable difficulty in the way of working simple engines at the same pressure as that in use at present with the compound engine at sea. Equal economy might, then, fairly be expected with the simple engine, specially fitted, as with the compound, under ordinary working conditions ; " and, " all available evidence goes to show that it is impossible that the compound engine can be to any serious extent superior to the rival engine, at present pressures, in point of economy." It is worthy of note that the first prize, in a professional competition, was awarded to this essay, the judges being Prof. Cot- terill, M.A., F.R.S. ; Chief Inspector W. Eames, R.N., the Chief Engineer of H. M. Dockyard, Chatham ; and the eminent engineer, J, Penn, F.R.S. The rapid perusal which alone we have been able to give to this large volume of more than 600 pages has disclosed to us but few blemishes, and these, for the most part, of the slighter sort, and such as are chiefly due to brevity of treatment. We will refer to those only which we observe in the first chapter. The remark that the equality existing between the total weight of water displaced by a ship and her own weight " is equally true of wholly submerged vessels as of ships of ordinary form having only a portion of their volume immersed," will create difficulty in the minds of some of the readers for whom the work is intended. The principle is doubtless true of vessels which just float, without any reserve of buoyancy above the water's surface, and which, therefore, are wholly submerged ; but its obvious inaccuracy when applied to the Vanguard^ the Eurydice, the Grosser Ktirfiirst and other ships which are very unfortunately, but nevertheless very certainly, "wholly submerged" points to the necessity for a modification of the language employed. Again, the statement that " the weight of the ship in tons multiplied by thirty-five gives the number of cubic feet in the volume of displacement " may puzzle some young readers of the work— and there should be many young readers of it among the naval cadets and others —who may fail to see that the number " thirty- five" is derived from the previous statement that 64 lbs. is the weight of a cubic foot of sea-water. It is impos- sible to make these elementary matters too clear for young sailor-officers. Such students will also require some assistance in understanding the paragraph in which the author explains the pressures acting on the bottom of a ship. Following the mathematical method of assuming the existence and action at every point of a pressure acting " perpendicularly to the bottom," and treating this as made up of three components, the author justly speaks of the vertical components only as affecting buoyancy, and no less justly dismisses the horizontal components, as they must, on each set, " obviously be exactly balanced amongst themselves." No youngster accustomed to the mathematical treatment of forces or pressures will find the slightest difficulty in all this ; but we can well imagine less favoured sailors, of all ages, pausing at the statement that the water pressure can "at every point" be resolved into three such components, and searching in vain for horizontal pressures, for example, under the flat bottom of a ship. It is, we are well aware, impossible to avoid difficulties of this kind without great elaboration ; but we hold it to be a primary necessity to avoid them to the utmost possible extent in a work like this, which has been expressly written for those very many per- sons, outside the naval architect's profession, who are " more or less intimately connected with ship- ping," and desire to get some knowledge of the sub- ject. In one important respect Ave think the author's explanations of the sub-division of ships into compart- ments, and of the consequences of admitting water into them, much too brief, viz., that of the division of ships by middle-line bulkheads. This is dismissed with the remark that the advantages of such bulkheads are too obvious to need comment; but however obvious the advantages of the system may be, the efifects of admitting water to the divisions so obtained should certainly have been investigated and set forth. In any case it would have constituted both an interesting and an instructive branch of the subject other parts of ^which the author has treated so fully and so well ; but the recent improve- ments in the Alexandra and other twin-screw ships has made it also a subject of great importance. The intro- duction of the middle-line water-tight bulkhead wherever it could be applied is one of the most valuable of the many valuable improvements introduced by Mr. Barnaby and his stafT since the first charge of our Admiralty Naval Construction became theirs, and officers who are " ship- mates" of this system (to use a naval phrase) will be disappointed to find it so summarily dismissed from the author' s and the reader' s notice. The defect is the more obvious because of the singular clearness and fulness with which the general question of sub-division is ex- pounded. The task of mentioning the blemishes and I40 NATURE \_yune 6, 1878 defects of so excellent and comprehensive a work as this is too distasteful to be pursued through more than a single chapter. It is impossible to conclude this notice of Mr. White's work, however — which, by the by, is well-indexed and turned out of hand by Mr. Murray in his usual style of efficiency and excellence — without reflecting upon the immense developments which naval architecture has undergone during the present century, is still undergoing, and has yet obviously to undergo. There is not a chapter in this volume of many chapters, which does not abound with illustrations and indications of improvement. " Men, my brothers, men the workers, ever reaping something new : That which they have done but earnest of the things that they shall do." Take, for a single example, the material of which the naval constructor builds his ships. How recently is it that wood was in universal use ; now far more than nine-tenths of the ships built are of iron. But already iron is being superseded by steel, and a few weeks ago Mr. Martell, the able Chief Surveyor of Lloyd' s Registry, said at the Institution of Naval Architects, " The time has now come when it is said by many others besides the manufacturers that steel can be used with as much con- fidence as iron ; and it is held that whilst the properties of mild steel are in every respect superior to those of iron^ the cost — having regard to the reduced weight required — will warrant the shipowner, from a commercial point of view, in adopting the lighter material." The manufacture of this "mild steel" for ship-building purposes, and indeed for many other purposes, is, as Mr. White states, " mainly due to the efforts of Mr. Barnaby, Director of Naval Construction, who had previously con- ducted most of the experiments on steel made in the Royal Dockyards, and done much to develop the use of the material." By insisting upon the combination of increased strength with great ductility in the material, Mr. Barnaby directed the attention of manufacturers to the great importance of turning their energies into a new direction, and the result has been the production of a most excellent material for the purpose, which can now be obtained in any quantity from several firms. But even these most recent forms of steel seem destined speedily to be replaced by the fluid-pressed steel of Sir Joseph Whit- worth, who, by the application of enormous force to the metal in a molten state, can solidify and make sound castings which contain whatever proportion of carbon may be desired. By pursuing this process through a thousand details, and many years of costly experiment, this distinguished man has given us a material which is as superior to the best mild steel produced otherwise as that is itself superior to the ordinary forms of ship- building iron, and the process promises to carry us to results of far greater importance still. It is perhaps one of the few reflections which should reconcile us to the persistence of mankind in the pursuit of the arts of war that the eager desire to improve guns and war-ships is continually conducting us to collateral and large improvements in the materials employed for the purposes of civilised life — for commercial ships profit no less than war-ships and guns by the improvements of men like Sir Joseph Whitworth, who has himself contributed immensely to the manufacturing arts, both directly and indirectly. The fields in which Mr. Froude is labouring are not less prolific than this, while the forms of vessels, and the propelling powers ap- plied to them, are receiving continual improvement. In respect of naval architecture, at least, Tennyson is right ; and that which we have done is but an "earnest" of the things sooner or later to be done. E. J. Reed TROPICAL NATURE Tropical Nature and other Essays. By Alfred R. Wallace. (London: Macmillan and Co., 1878.) MR. WALLACE tells us that the luxuriance and beauty of tropical nature is a well-worn theme and that there is little new to say about it, and yet he thinks that none have as yet "attempted to give a general view of the phenomena which are essentially tropical or to determine the causes and conditions of those phenomena. Indeed many very erroneous ideas are commonly entertained about the charms of the tropics and about the brilliant tints of its flowers, and birds, and insects. In the first three chapters of this most interesting volume Mr. Wallace treats of the climate of the tropics, of its vegetation, and of its animal life. A fourth treats of the humming-birds as illustrating the luxuriance of tropical nature. The next two enter on the discussion of the nature and origin of the bright colours of animals and plants, showing how far and in what way these are dependent on the climate and physical conditions of the tropics. A seventh chapter contains an account of certain curious relations of colour to locality, which are almost exclusively manifested within the tropical zones, while the next and last chapter tries to explain the pro- bable origin of many of the forms of life now charac- teristic of tropical regions. Despite its being a well-worn theme and its want of novelty, Mr. Wallace has succeeded in writing a most interesting volume on the peculiarities of tropical life, and this chiefly from the results of his own long expe- rience of nature in the eastern and western tropics of the equatorial zone, while his theory to account for the diverse colours, the special adornments, and the brilliant hues which distinguish certain male birds and insects — a theory quite opposed to that of Mr. Darwin' s — cannot fail to attract the attention of all interested in this subject. Mr. Wallace's account of his theory is perhaps the most important portion of his book ; he finds, on close examination, that neither the general influence of solar light and heat, nor the special action of variously-tinted rays, are at all adequate causes for the many wondrous complexities of colours with which we are acquainted. He would therefore take another view, dividing the colours into groups, as they are protective to the creature, act as warning colours, or sexual colours, or typical colours, or simply as in floras, attractive colours. Mr. Darwin' s theory on this subject of colours was that all, or almost all, the colours of the higher forms of animal life were due to voluntary or conscious sexual selection, and that diversity of colour in the sexes is due at least, first of all, to the transmission of colour varia- tions either to one sex only or to both sexes, the difference depending on some unknown law and not being due to June 6, 1878] NATURE 141 simply natural selection ; but Mr. Wallace regards this view as erroneous, and to him the very frequent supe- riority of the male bird or insect in^brightness of colour, even when the general coloration is the same in both sexes, seems to be due primarily to the greater vigour and activity and the higher vitality of the male- He reminds us that the colours of an animal usually fade during disease or weakness, while robust vigour and health add to their intensity. This intensity is most developed in the male during the breeding season. It is also very general in those cases in which the male is smaller than the female. This greater intensity of coloration in the male would be further developed by the combats of the males for the possession of the females. Increased vigour, acting thus on the epidermal system, would soon produce further distribution of colour, and even new tints and markings. Nay, even the remarkable display by so many male birds of their pecu- liar beauties of colour and plumage may be thus ac- counted for ; for at the pairing season these birds are in a state of the greatest energy. Even unomamental birds, at such a season, flutter and spread out their wings and erect their head-crests or their tail-feathers ; and there would be a progressive development of these ornaments in all dominant races, and if those portions of the plumage which were originally erected under the in- fluence of anger or fear became largely-developed and brightly-coloured, the actual display under the influence of jealousy or sexual excitement would be quite intel- ligible ; the males would soon find what plumes were most effective, and would endeavour to excel their rivals. It will thus be seen that Mr. Wallace's theory of colour might almost be called a molecular one. The causes of colour are due to molecular or chemical changes of certain substances, and on the action on these of light, heat, and moisture. They can be produced or intensified by processes of development, and this as the surface bearing these colours is extended or diminished and as there is a surplus of vital energy ; or they may be, as in plants, acted on by some, as yet, unknown local action dependent on the soil or on vegetation. Doubtless this theory will give rise to much contro- versy; and in the course of this, no doubt, many import- ant facts will be elucidated. Thus, Mr. Wallace reminds us that, in the case of those female birds with brighter plumage than the males, the females are larger, more pugnacious, and show more of vital energy. One portion of tropical nature Mr. Wallace has over- looked in the volume — that which spreads its brilliant colouring over the white rocks that lie under the sea. Crowds of lovely forms are here ; and they are worthy of a chronicle. E. Perceval Wright I LETTERS TO THE EDITOR \The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts. No notice is taken of anonymous communications. [The Editor urgently requests correspondents to keep their letters rtf short as possible. The pressure on his space is so great that it is impossible otherwise to ensure the appearatue even of com- munications containing interesting and novel facts.l Extinct and Recent Irish Mammals Prof, Boyd Dawkins, in his interesting "Preliminary Treatise on the Relation of the Pleistocene Mammals to those now living in Europe," just published by the Palaeontographical Society, places the Irish elk {Cervus megaceros) among the pre- historic mammals in consequence of its presence "/« the peat hogs of England, Scotland, and Ireland ; " indeed, in a former monograph on the British Pleistocene Mammals, by Messrs. Dawkins and Sandford, and published by the same Society, it is stated that "the C. megaceros, C. tarandus, C. elaphus, and Bos longifrons, have been found associated in peat in Ireland.^^ Now although remains of the red deer and short-horned ox are not unconmion in Irish turbaries, there is not a single authenticated instance of either the Irish elk or reindeer having been discovered in peat. This observation as regards the Irish elk was made by Prof. Owen long since (1846) in the " British Fossil Mammals," and a wide field of observation confirms my impression of its truth as far as Ireland is concerned. More- over, there is no reliable evidence to show that man and the Irish elk, reindeer, mammoth, horse, and bear, were contempora- neous in this island. With reference to the smaller Irish mammals referred to in j Mr. Dawkins's treatise. On the authority of Wilde and others it is stated that both the Martesfoina and M. abietum are natives. The former, at best a doubtful British species, has never been authenticated in Ireland, but the latter is not uncommon. Again, neither the weazel {M. vulgaris) or polecat {^. pa- torius)ha.ve any claims to be included in the Irish fauna. As to Eelis catus there is much doubt, the individuals being in all pro- bability domesticated cats run wild. In regard to the rodents given in Mr. Dawkins's list as Irish, neither the Arvicola agrestis nor the Arvicola amphibius have been identified ; but on the other hand, the house mouse (M. musculus), reported absent, is unfortunately too plentiful in many districts. The red deer is still a native of the mountains around the Killarney Lakes, and until recendy a few lingered in the wilds of Connaught, but certainly it is not just now on the Tipperary Mountains, though the fallow deer does occur there. Of the shrews, none of which are given in Mr. Dawkins's list, the pigmy {S. pygmceus) is the only species hitherto identified in Ireland. I mention these facts, having lately bestowed much attention to the study of Irish mammals. A. Leith Adams Royal College of Science, Dublin, May 25 Hints to Workers with the Microscope I AM now and have been for the last fortnight enjoying a treat which everyone who possesses a microscope, a slip of glass to lay on the stage, and a piece of thin microscopic glass with a little cottonwool, can enjoy for the price of is. Mr. Bolton, formerly of Stourbridge and now of 17, Ann Street, Birmingham, sends me weekly supplies of rotifers, and has just sent me Rhinops vitraa and Hydatina senta in gi'eat profusion. With ordinary co7n- pressorui and live boxes these are troublesome to see, as they are very lively rovers. To those who may not know the Midland Naturalist or the Microscopic Transactions, I recommend a par- ticular method which I recently sent to those publications. — Take a plane glass slide, on it drop one or more of the rotifers in a drop of water about halfan-inch in diameter, and draw off the surplus water, if any, carefully with the empty pipette. Then fray out a very very small portion of cotton wool (I always use a watchmaker's glass in the eye to do all such operations) until it is much extended, and spread out and lay this on the drop. Upon that lay the thin microscopic glass, the thinner the better, and then set up the capillary attraction by gently touching it m ii h a needle. Draw off any superfluous water from the edges with the pocket-handkerchief and you will have a little wilderness of wool in which the rotifer is restrained in its movements, pro- tected from pressure, and within reach of very high powers. The amount of avooI depends on the size of the rotifer. Hyda tina requires more depth than rhinops. The same plan answers equally well for all roving animals. The poduridas in par- ticular when placed in deep glass cells are easily seen by this apparatus, and it saves many a weary and vexatious five minutes with the compressorium, which, even at the best, requires with living animals extraordinary patience. The rotifers are easily found and secured with the pipette and a watchmaker's glass in the eye after a veiy little practice. Mr. Bolton's studio is of the greatest value to naturalists and cannot be too well known, for to those who have not time to look for specimens it is a great privilege to be able to purchase them. Fort Hall, Bridlington Quay, Yorks, F. A. Bedwell May 25 142 NATURE [Jtine 6, 1878 The Virial in Thermodynamics In my letter on the Virial in Nature, vol. xviii. p. 39, a line of the description of a force's " radiancy " (as it was there termed) with respect to a given point was accidentally omitted ; and the definition should have been the product of the distance of its point of application from the given point or " focus," and the resolved part of the force in the direction of that distance, the last and most important member of which product was unmen- tioned by some unintentional oversight in the description. It would also be wrong, in the dynamical equation of the virial, the vis viva and the radiancy of momentum of a system to range the vis viva and virial together (as I did in the letter) in the class of physical agents, bound therefore by known laws of conservation, since either their joint or their separate effects in changing the system's total radiancy of momentum are easily seen, if we sup- pose one of them, for example, the vis viva, to act alone, to be totally unfettered, and therefore their actions to be of a measur- able kind, but not subject, like that of natural agents, to any known laws of physical connection. The rate of acceleration of a fourth part ^ of the triple sum formed of a system's moments of inertia round any three axes at right angles to each other is the rate of change of its total radiancy of momentum, and if the various parts of the system are all moving uniformly in straight lines, their joint vis viva measures the rate of this change ; but it cannot be said to cause or pro- duce it, since, by the laws of motion, the bodies unassisted or left to themselves will continue to produce, by their vis viva, the same rate of change, without connection in doing so, with any known physical agent, from whose class, accordingly, it is evident that both vis viva and the "virial," or the radiances of a system's forces as linked in an equation with acceleration of total moment of inertia, are formally excluded. The equation has very important applications : as when, on an average of a sensible time, the total moment of inertia remains unaltered, or when a system is apparently at rest : for example, in the case of immobihty of a gravitating atmosphere in a state of eqailibrium, under any possible assigned law of variation of temperature. But the idea of this state of immobility being a necessary one, which the vis viva and virial together of the ponderable mass is constrained to conserve — placing them together in a fixed and definite relationship to each other, or to any other agents of physical phenomena, subject to known laws of conservation — was evidently a totally mistaken and unreal one. A. S. Herschel The Meteor of May 12 In Nature (vol. xviii. p. 105) the statement occurs among the "Notes" that the brilliant bolide of May 12 was seen at Geneva, the local time being said to agree. May I call your attention to the fact that the difference between Greenwich and Geneva is 25 minutes (or 2 minutes more if Berne time is com- pared). Thus 9.45 is 9.20 Greenwich time, nearly half an hour after the meteor recorded by English observers. It is now a well recognised fact that large meteors come in groups, naturally raising the suggestion that such groups form part of a slowly disintegrating mass. Fi-om records I have obtained from Scarborough, Leeds, and Bradford, combined with an excellent observation of the latter part here, and the notices contained in your number for May 16, I find the probable positions of beginning and end to be from 4 miles west of Northallerton to 5 miles west of Hawick, a distance of 94 miles, the angle of flight being 38° with the horizon, making an actual com'se of 108 miles described in about 9 seconds, giving the unusually slow rate of 12 miles per second. This, and one or two other points, make it possible that the course really extended further. But the end was in nearly all instances obscured by clouds and the observations in line with the meteor's course. An exact description of its course by your Edinburgh correspondent (especially as to whether it passed near the zenith) would make this certain. May I venture to make one or two suggestions to your corre- spondents who favom- you with notes on meteors ? When, for any reason, celestial measurements cannot be given, rough measurements of the positions made either by holding a ruler in front of you, or, if light allows, by the minutes upon a watch I The acceleration of the total moment instead of the fourth part of the total moment of inertia was wrongly written in the postscript of my letter as equal to__ the rate of change of momentum-radiancy. Actual energy and vmai, as defined by Clausius, are also half of the quantities here described as VIS viva, and radiancv of a force. lace, \\hich shall enable the actual height, and distances from a point of the compass to be determined, are by far the most valuable items, accompanied of course by exact time, date, and place. Thus a meteor might appear at a height of 15 inches on a base 27" (an arm's length) and 12" W. of north. Oi", having placed 12 o'clock level, the hand at 10 minutes past might point to the place of disappearance, an angle of 7 minutes (42°) giving the distance E. of south. Prof. Herschel, of Newcastle, gives some capital hints in a letter published in the Scotsman, May i, upon the March daylight meteor. Either he or Capt. G. L. Tupman (or I myself) would at any time be glad of observations, in which case a rough plan, indicating its position among the stars, would be of great value. The position of the meteor with reference to houses, trees, &c., the course across a window, if seen indoors (the observer's position and distance being also given and the points of the compass), and many similar items are very useful for after reference and maylead to very exact determina- tio"^- " J. Edmund Clark 20, Bootham, York, May 28 "Divide et Impera" Verily we have divided and subdivided, and as yet are but little nearer the "conamand" promised. I am a subscriber to your able magazine, which is extensively read in South America, and beg to bring the following subject to the notice of your zoological readers : — At this distance of 8,000 miles and at the outskirts of civilisa- tion, books of reference are scarce, or, if existing, difficult ot access. In constructing some zoological tables I am constantly beset by the difficulty of discovering two, three, four, five, six, or more synonyms for the same species, or in the case of a sup- posed new species find afterwards that the same animal has been described under another name ; the genera often differ ! the families constantly vary, and even the higher classification is by no means constant. Where is all this perpetual confusion to end ? In the science being destroyed by excessive or faulty nomenclature ? We want an Ariadne with her thread to lead us out of the maze, for such it is, especially to young zoologists like myself. Is it too much to expect that an international zoological con- gress should be constituted with power to methodise and reduce to order this chaotic classification, and print and publish autho- rised lists of fauna? How are young naturalists to progress, constantly hindered as they are by wasting weaiy hours in seeking for that which should be patent at a glance ? Such a congress should, by unanimous consent of the chief zoological societies of Europe, fix immutably not only the supe- rior classification, but also the generic and specific nomenclature ; and in the event of new species being discovered, whilst con- ceding the right to the discoverer and describer to affix its title, this should in all cases be subject to the approval of the Inter- national Congress, which might sit permanently in the shape of one or two deputies. It seems to me the science has already emerged from its swaddling clothes, and it is high time for om: scientific authori- ties to give up that fatal habit of generating and clinging to their own superstitions, and fostering that intense jealousy so charac- teristic of them, which, leading to multiplicity of systems, leads only to distraction. There may be aberrant forms yet undecided (there will be such, perhaps, to the end of time) ; borderlands to be limited ; yet there is ample material to fix unalterably and universally the skeleton of that science, to fill in whose details there are multi- tudes of willing and skilled hands, ready to aid, in all parts of the world. E. W. White Buenos Ayres, May i A Quadruple Rainbow In the afternoon of Friday, the 24th ult., while proceeding by rail to Dublin, and before reaching Abbeyleix station, I observed the curious phenomenon of four rainbows forming a single bow — that is, without any dark space intervening between the colours. The four bows were all of the same, or nearly the same, breadth, but I cannot say whether all the colours were present in each. The brighter colours — as the red and yellow — showed that the bows were arranged in the same order. I called the attention of several other passengers to the novel spectacle. June 6, 1878] NATURE 143 A word in explanation of this strange appearance from some of your learned contributors would, I think, be interesting. Model School, Waterford, June i Henry P. Dowling Classes for Women at University College ■ In view of the new charter enabling the University of London to confer degrees on women, and the increased demand for a higher education of women, the council of this college have determined to provide for them systematic instruction in regular college classes. In most subjects the junior classes for women will be distinct from those attended by male students. The senior classes will more generally be open to both sexes, and these classes, which are already open to both, as fine arts, philosophy of mind, &c., will remain so. Prospectuses embodying the results of this change will be ready by the i8th inst. Talfourd Ely University College, London [Our St. Petersburg correspondent, " C. S." must send us his name (in confidence), before we can publish his last communi- cation.] PROF. JOSEPH HENRY, LL.D. p ROF. HEN RY was born December 17, 1 797, at Albany, New York, where also much of his early life was passed. The year of his birth seems, however, uncertain, some authorities placing it in 1 799, or even later. He had at first the advantages of only a common school education. A parish library supplied him with boyish reading, and his early tastes were in the direction of romance and the drama. He was nearly grown when the accidental possession of a copy of Robinson's "Mechanical Philosophy" turned his thoughts towards natural philosophy. After two years of work as a watchmaker, he came under the training of the Albany Academy, where he developed a degree of mathematical talent which, in 1826, led to his selection for the duties of in- structor in mathematics in that institution. Prior to this, having had some experience in the field as a surveyor, he was associated with Amos Eaton in the Geological Survey along the line of the Erie Canal, pro- jected and sustained by General Stephen van Rensselaer. Failing physical health led to his taking this step. He returned home with a' robust constitution, which never failed him throughout his life. While occupied with his duties as mathematical in- structor in the academy— then in charge of Dr. T. Romeyn Beck — he commenced that line of investigation in electricity which resulted in the important discoveries that have made his name famous. He attended the lectures on chemistry of Dr. Beck, and assisted in the preparation of his experiments. At this time he devised and published an improved form of Wollaston's sliding- scale of chemical equivalents, in which hydrogen was adopted as the radix^a contrivance which is hardly known, even by name, to the present generation of chemists. Thus, while Prof. Henry's original contributions to science were chiefly physical, his first scientific work was in the department of chemistry. His work with Dr. Beck enabled him, after his removal to Princeton — where he became professor of natural philosophy in 1832, — to take up the duties of the chemist, Dr. John Torrey, when that well-known teacher was disabled for a time by ill health. It was in the interval between 1828 and 1837 that the most important work of his life was accomplished in the line of strictly scientific research. If we compare the poverty of his apparatus and the poverty of his means for research and publication with the importance of the results which he reached, we may accord him a place by the side of Faraday as an experi- mentalist. He became the sole discoverer of one of the most singular forms of electrical induction, and was among the first, perhaps the very first, to see clearly the laws which connect the transmission of electricity with the power of the battery employed. One of the problems to which he devoted himself was that of producing mechanical effects at a great distance by the aid of an electro-magnet and a conducting wire. The horse-shoe electro-magnet, formed by winding copper wire round a bar of iron bent into the form of a U, had been known before his time, and it was also known that by increasing the number of coils of wire greater force could be given to the magnet, if the latter were near the battery. But when it was removed to a distance the power was found to weaken at so rapid a rate that the idea of using the electro-magnet for telegraphic purposes seemed hopeless. Henry's experiments were directed toward determining the laws of electro-motive force from which this diminu- tion of power resulted, and led to the discovery of a relation between the number of coils of wire round the electro-magnet and t'oe construction of the battery to work it. He showed that the very same amount of acid and zinc arranged in one way would produce entirely different effects when arranged in another, and that by increasing the number of cells in the battery there was no limit to the distance at which its effects might be felt. It only remained for some one to invent an instrument by which these effects should be made to register in an intelligible manner, to complete the electro-magnetic telegraph, and this was done by Morse. Henry himself considered the work of an inventor as wholly distinct from that of a scientific investigator, and would not pro- tect the application of his discoveries, nor even engage in the work of maturing such applications. He never sought to detract from Morse's merits as the inventor of the magneto-electric telegraph, but did on one occasion, under legal process, give a history of the subject which was not favourable to Morse's claim to the exclusive use of the electro-magnet for telegraphic purposes. Some feeling was thus excited ; but Henry took no other part in the controversy than to ask an investigation of some charges against himself contained in an article of Morse's. The results of these researches are chiefly recorded in the Transactions of the Albany Institute, the volumes of the American Jojirnal of Science and Arls for the period, and the Transactions of the American Philosophical So- ciety. His " Contributions to Electricity and Magnetism " were collected in a separate volume in 1839. The analysis of these important researches, and the discussion of the questions of priority connected with them, will be the duty of the academician to whom shall be assigned the prepara- tion of a memoir or eulogy of the distinguished author. The memoir in the American yourtial gives a list of twenty-two memoirs and discoveries by Prof. Henry. To these papers should be added an important series of communications, made chiefly to the National Academy of Sciences during the past four or five years, upon the laws of acoustics as developed in the course of investigations conducted for the Light-House Service in order to determine the various conditions in- volved in the transmission of fog-signals. These investigations have been carried forward mainly in government vessels, and occupied Prof. Henry's close personal attention during many weeks of each season. Besides these experimental additions to physical science. Prof. Henry is the author of thirty reports, between the years 1846 and 1876, giving an exposition of the annual operations of the Smithsonian Institution. He has also published a series of essays on meteorology in the Patent Office Reports, which, along with an expo- sition of established principles, contain many new sugges- tions, and, among others, the origin of the development of electricity, as exhibited in the thunderstorm. In 1837 he visited Europe and made the acquaintance 144 NATURE \yune6, 1878 of Faraday, Wheatstone, Bailey, and other eminent physicists, discussing with Wheatstone their projects for an electric telegraph. He returned to his lectures with the zest and vigour acquired by this exchange of views with men of like pursuits with himself, and held his place as the foremost of American scientific teachers until 1846, when he was called to an entirely different sphere of activity. Ten years before Congress had accepted, by a solemn act, the curious bequest of James Smithson, made to the United States in trust, "to found at Washington an establishment for the increase and diffusion of knowledge among men." The will gave no indications whatever as to the details of the proposed establishment, and long consideration was therefore necessary before the Govern- ment could decide upon its organisation. It was not until 1846 that a definite plan of organisation was estab- lished by law. When this was done Prof. Henry was at once looked upon as pre-eminently the man to be the principal executive officer of the institution. He accepted the position with " reluctance, fear, and trembling," upon the urgent solicitation of Prof. Bache. From the be- ginning two different views of the proper direction in which the energies of the establishment should be devoted have been entertained. There was a scientific party, which held that the operations of the establishment should be confined strictly within the limits prescribed by the donor, and in the sense in which he himself, as a scientific investigator, would naturally have construed his own words— in fact, that it should be entirely an institu- tion for scientific research and publication. Another party was desirous of giving it a larger scope and wider range, including literature and art as well as science. The new secretary, of course, sympathised entirely with the scientific party, who considered most of the objects proposed by the other party as foreign to the proper purpose of the institution, and the expenditure of money upon them as contrary to the expressed intention of the donor. The whple policy of Henry was directed towards diminishing, as far as possible, the expen- diture of the Smithsonian fund upon the library, the building, the museum, and art-gallery, by having these several objects provided for in other ways. He got the library removed to the Capitol and deposited in the Library of Congress, and the art-gallery superseded by the Corcoran Gallery of Art. The impropriety of charging the Smithsonian fund with the support of the govern- mental collections was so obvious that Congress has for several years provided for the maintenance of the National Museum, as it has now become, in connection with the institution. He aimed at a complete separation of the museum from the institution; the Government leasing the building for the use of the former, while the latter should find more modest and appropriate but less expensive quarters. This project, however, he did not live to carry out. Henry was, of course, the authority most frequently and regularly consulted by the Government on all ques- tions which arose involving applications of science or of scientific principles. His greatest services to the Govern- ment were rendered as a member of the Light-House Board, a position which he held from the time the Board was organised. His principal duties were at first to mquire into the various methods of illumination and especially to test the oils proposed for this purpose. Of late years he began to investigate the subject of fog- signals, which led to a very extended series of experi- mental researches on the causes which influence the propagation of sound through the air, and which some- times render It inaudible at comparatively short distances innr?=^J'!^'''\^^^f '?/^ '^°'^^>^ pubHshed in the annual reports of the Light-House Board. weather rennrlf"^- '^^ '^^^^'^V^ ^r communicating the weathei reports originated with Professor Henry, and was put in operation at the Institution at an early period of his connection with it. It was while engaged in the discharge of certain experi- mental work on Staaten Island last December, connected with the photometric laboratory of the Light- House Board, that he experienced a partial paralysis, which yielded soon to treatment, but was doubtless the precur- sor of the nephritic attack to which he succumbed. In April he presided at the opening meeting of the session of the National Academy of Sciences, held in the rooms of the Secretary of the Smithsonian, and submitted an address to his associates, read by the Home Secretary, recounting with touching simplicity his recent decline of power, and expressing his desire to be relieved from the cares of the office of President. As a mark of affection- ate respect, the Academy unanimously requested him to retain this post during his life— leaving the duties to be discharged by the Vice-President. It was on this occa- sion that the announcement was made to the Academy, by Prof. Henry, and, subsequently, in fuller details, by Prof. Fairman Rogers, the treasurer, of the creation of an endowment to be called " the Joseph Henry Fund." This fund consists of forty thousand dollars, securely invested, the income of which is for the support of Prof. Henry and that of his family, during the life of the latest survivor. Afterwards the fund is to be transferred, in trust, to the National Academy of Sciences, the income to be for ever devotedjto scientific research. No more graceful and well-merited tribute of respect and affection Avas ever bestowed upon a man of science by the spon- taneous offerings of personal friends and associates. Alas ! that its honoured object should have remained so brief a time to enjoy the peace and satisfaction of this gracious endowment. If it is true that republics are ungrateful, it is pleasant to know that the absence of imperial and kingly patronage may be compensated by a sovereignty not less potent. The whole course of Prof. Henry was marked by an elevation of character entirely in keeping with his intel- lectual force. Placed in a position where the temptation to lend the use of his name to commercial enterprises was incessant, he so studiously avoided every appearance of evil that the shadow of suspicion never rested upon him. His services to the Government in many capacities, espe- cially in that of member of the Light-House Board, where his experiments saved it hundreds of thousands of dollars, were entirely gratuitous. His salary was paid from the Smithsonian bequest, and he never asked the Government for a dollar on account of his services. An elevated but genial humour, a delicate poetic taste, a memory replete with anecdote, a refined intellectual face, and an impressive bearing made him one of the most valued members of the intellectual society of Washington. Prof. Henry leaves a wife and three unmarried daughters, who have been assiduous helpers in the scien- tific work of their father, making good to a degree the loss of an only son, whose death in early manhood was a sad disappointment of parental hopes and youthful promise. Prof. Henry was buried May 16, in the Rock Creek Cemetery, near Georgetown, D.C. The President of the United States, the cabinet officers, diplomatic corps, and members of Congress and of the National Academy, were among the mourners. Prof. Spencer F. Baird, long the Assistant-Secretary to the Smithsonian Institution, was, on May 17, unanimously elected by the Board of Regents as Prof. Henry's suc- cessor in the office of Secretary of that institution. No more acceptable appointment could have been made. _ We express our indebtedness to Prof. Silliman, who has kindly forwarded us early sheets of an article on Prof. Henry to appear in the American Jotirnal of Science and Arts. From this, together with an article in the New York Nation, we have gathered most of the above details of Prof. Henry's life and work. Jtine 6, 1878J NATURE 145 MAJOR-GENERAL SIR ANDREW SCOTT WAUGH FROM a paper in the Royal Engineer Journal, we obtain some interesting facts concerning the career of this able officer of the Indian Survey, whose death we announced at the time (vol. xvii. p. 350). Having been appointed in July, 1832, and retiring in i86r, his services in the department extended over a period of close upon thirty years. Under Col. Everest, as his astronomical assistant, Waugh took part in the measurement of the great arc of the meridian extending from Cape Comorin, the most southern point of the peninsula of India, to the Deyrah Doon at the base of the Himalayas. In December, 1834, we find him with his Chief at the measurement of the northern base-line in the above valley, an operation that extended over a year. In the connection of this base with that near Sironj, about 450 miles to the south, Waugh took a large share of work, and also, in 1 837, at the re- measurement of this *Sironj base with the new bars that had been used in the Deyrah Doon. The wonderful accuracy secured on these grand operations may be esti- mated by the difference of length of the Deyrah base-hne, as measured, and as deduced by triangulation from Sironj, being only 7-2 inches. He shared with Everest the arduous observatory work, carried on simultaneously at the stations of Kaliana Kalianpur, and Dumargidda, by which the arc of ampli- tude was determined, and brought this important work to an end in 1841. Between 1834 and 1840 he was also conducting the Ranghir series in the North-West Pro- vinces, and in 1842, the triangulation through the malarious Rohilkund Terai, which Everest acknowledged to be " as complete a specimen of rapidity combined with accuracy of execution as there is on record." Sir Andrew thus had the good fortune to be the immediate pupil of the great geodesist who placed the Indian Surveys on their present footing, for the whole system was then, elaborated and brought to a high pitch of excellency This, Waugh, on succeeding to the appointment of Sur- veyor-General and Superintendent of the Topographical Survey in 1843, made it his first object to keep up and improve. Sir George Everest's high opinion of the man who had served under him on so many important opera- tions may be understood from the singularly strong terms which he used when recommending Waugh as his successor. He began by carrying out the remaining series, seven in number, a total of 1,300 miles in length and embracing an area of some 28,000 square miles, originating from the Calcutta longitudinal series on the gridiron system pro- jected by Sir G. Everest, The eastern side was formed by the Calcutta meridional series (begun in 1844 and finished in 1848), which terminated in another base-line near the foot of the Darjeeling hills. One of the finest of surveying operations, commenced about this period of Sir A. Waugh's tenure of office, was the north-east Himalaya series, connecting the northern ends of all the before-mentioned meridional series. In these field-operations Waugh took a leading part. The line of country was along the base of the Himalayas (the Terai). These operations led to fixing the positions and the heights of some of the highest and grandest of the Himalayan peaks in Nipal and Sikkim ; one of these, 29,002 feet above the sea, was named by Waugh Mount Everest, and was found to be the highest in the world ; its name, one well-known to the natives, is Devidanga. Mr. Clements Markham, in his exhaustive memoir on the Indian Surveys, states that the dangers and difficulties in the execution of this work were air greater than have been encountered in the majority of the Indian campaigns. On the South of India, the South Concan, the Madras coast series, the South Parisnath and South Maluncha series were also begun and finished, and several pages might be written of the dangers and difficulties the Survey Staff had to contend with. Of all the Indian Survey work that originated in Col. Waugh' s tenure of office, on account of the general interest attaching to the country, its beauty, and its vastness, the survey of Kashmir was chief. This important and difficult survey, finally com- pleted in 1864, was in full swing of work at the time Sir Andrew Waugh retired from the department, and we cannot do better than quote the lines the late Lord Canning was pleased to write privately to Sir Andrew Waugh in July, 1859, on being shown the first instalment of this work. Coming from so high and intelligent a source, they are a tribute not only to the Surveyor- General, but to the whole department. " I cannot resist telling you at once with how much satisfaction I have seen these papers. It is a real pleasure to turn from the troubles and anxieties with which India is still beset, and to find that a gigantic work of permanent peaceful useful- ness, and one which will assuredly take the highest rank as a work of scientific labour and skill, has been steadily and rapidly progressing through all the turmoil of the last two years. I never saw a more perfect or artistic- like production of its kind than this map." The other meridional series were also pushing forward. Jogi Tila by Jhelum and the Gurhagurh by Umritsur to join the Arumlia. Kattywar and Cutch must also be in- cluded. For a full and detailed account of these many difficult operations that comprise every kind of country and climate that India presents, we must refer the reader to the memoir before-mentioned. Space will not allow us to enter into detail of all the important work done for the survey of India during Waugh's tenure of office, but it may be stated roundly that he advanced the triangulation by no less than 316,000 square miles, an area three times that of England, Wales, Scotland, and Ireland, and of this 94,000 were topo- graphically surveyed. Col. Waugh retired from the service in 1861, receiving as usual the honorary rank of Major-General, and Her Majesty conferred on him the honour of knighthood in the same year. He had held the post of Surveyor-General for seventeen years, had main- tained the high character of the survey, and was highly esteemed by the whole department. The results of the work during his incumbency are given in some thirteen different volumes and reports deposited in the India Office, parts of which originally complete appear to have been lost. In 1856 the Royal Geographical Society pre- sented him with their gold medal, and in 1858 he was elected a member of the Royal Society. For some years past his health had been failing, and he suffered much, dying on February 21, 1877, at his residence in South Kensington. THE HARVEY TERCENTENARY C\^ Saturday evening the Royal College of Physicians ^^ commemorated the tercentenary of Harvey, the dis- coverer of the circulation of the blood, by a banquet in the library of their institution in Pall Mall. The presi- dent, Dr. Risdon Bennett, occupied the chair, and the company included the Marquis of Ripon, Viscount Card- well, Mr. Gladstone, M.P., Mr. Lowe, M.P., Mr. Spencer Walpole, M.P., Baron Cleasby, Mr. Justice Denman, Prof. Huxley, Dr. Allen Thomson, Prof. Owen, Capt. Cameron, R.N,, Dr. Carpenter, Mr. Benett- Stanford, M.P., Dr. Lyon Playfair, M.P., the President of the Royal College of Surgeons, the President of the College of Physicians, Ireland, Dr. Richardson, Sir W. Jenner, and Sir W. Gull The Marquis of Ripon and] Mr. Walpole, M.P., in responding to the toasts 'of the House of Lords and the House of Commons, respectively, paid highftributes 146 NATURE [Jime 6, 1878. to the memory of Harvey and to the reputation of the College of Physicians, while Lord Cardwell spoke with much satisfaction of the legislation resulting from the investigations of the Commission on Vivisection. The speech of the evening, however, was undoubtedly that of Prof. Huxley, in responding to the toast of the evening, " The Memory of Harvey," proposed in happy terms by the President. Prof. Huxley replied as follows : — Mr. President, — In attempting to fulfil the task you have imposed upon me, I am mindful that I address myself to an audience which is already familiar with William Harvey's claims to the honour which we are assembled to show him. For, within these walls, the memory of your illustrious Fellow and chief benefactor, is kept perennially green by the customary piety of the speaker of the annual oration which Harvey founded ; and his merits have been placed before you, with ex- haustive completeness, by a long succession of able and eloquent orators. Even if the time and place were fitted for a disquisition on these topics, I could not hope to be able to add to the facts already known, or to place them before you in a new light. And, happily, this is not my function ; I hare to act simply as your remem- brancer, to play the part of the herald who announces the familiar titles of a monarch on a state occasion. Harvey's titles are three — he was the discoverer of the circulation of the blood; he wrote the "Exercitatio de Motu Cordis et Sanguinis"; he formulated anew the theory of epigenesis, and thereby founded the modern doctrine of development. His first and, in general estimation, his greatest title to our honour has been challenged ; but only to the con- fusion of the challengers. A century ago, your Fellow, Dr. Lawrence, in the excellent memoir prefaced to the College edition of Harvey's works, met the arguments of those who had, up to that time, attempted to dim his fame, with a solid refutation, which has never been answered and to my mind remains unanswerable. In our own day. Dr. Willis has stated the facts of the case, and deduced the in- evitable conclusion, with no less force and cogency. And, having taken some pains to get at the truth of the matter myself, I may state my clear conviction that Harvey stands almost alone among great scientific discoverers, not so much that, as Hobbes said, he lived to see the doc- trine he propounded received into the body of universally accepted truth, but because that doctrine was both abso- lutely original, and absolutely new. I have yet to meet with a single particle of evidence to show that, before Harvey declared the fact that the blood is in con- stant circular motion, there was so much as a suspi- cion on the part of any of his predecessors or con- temporaries that such is the case. Neither in Galen, nor in Servetus, nor in Realdus Columbus, nor in Ceesalpinus, is there a hint that a given portion of blood sent out from the left ventricle, passes through the body and the lungs, and returns to the place from whence it started ; yet this is the essence of Harvey's discovery. Hence when we hear of pompous inscriptions being put up in Spain to Michael Servetus, " the discoverer of the circulation," or in Italy to Csesalpinus "the dis- coverer of the circulation;" it is well to recollect that churchyards have no monopoly of unhistorical inscrip- tions. Indeed, have we not ourselves, within easy walk- ing distance, that famous monument, the subject of Pope's scathing but just lines — " And London's column, soaring to the sides Like a tall bully, lifts its head and lies." Sir, I have no sympathy with Chauvinism of any kind, but, surely, of all kinds that is the worst which obtrudes pitiful national jealousies and rivalries into the realm of science. We will not shame ourselves by permitting the fact of Harvey's English birth to enter into the consider- ation of his claims as a discoverer ; but those claims once established beyond dispute, it is, I hop;, something nobler and better than mere national vanity which brings us together to celebrate his birth ; to take an honest pride that such a man came of our English race ; and as, I hope, to feel the deep responsibility which is laid upon us to have a care that the stock which in the same hundred years bourgeoned out in a Harvey and a Newton, shall not have its capacity for producing like growths in the present and in the future, starved by devotion to mere material interests, or stunted by ignorant outcries against scientific investigation. The second title which I have claimed for Harvey is that of author of the "Exercitatio de Motu Cordis et Sanguinis." And that title is, happily, quite indis^ putable. But some may suppose that I have so far thrown myself into the spirit of my assumed office as to insert a superfluous appellation — a sort of " Defender of the Faith." However, this would be an error. Harvey might have discovered the circular course of the blood ; he might have given sufficient evidence of his discovery ; and yet he might have been quite incapable of writing that little essay of fifty pages which no physiologist of the present day can read without wonder and delight. For, not only is it a typical example of sound scientific method and of concise and clear statement ; but, in addition to the evidence of the course of the blood through the body, it contains the first accurate analysis of the motions of the heart ; the first clear conception of the mechanism of that organ as a pumping apparatus ; the first application of quantitative considerations to a physiological problem ; and the first deductive explana- tion of the phenomena of the pulse and of the uses of the valves of the veins. " Libellus aureus," Haller called it — and never was epithet more aptly bestowed. Harvey's third title to honour is the authorship of the " Exercitationes de Generatione." In this treatise Harvey grapples with two of the most difficult pro- blems of biology — the physiological problem of genera- tion and the morphological problem of development. It was simply impossible that he should solve these problems, for they can be approached only through the microscope ; and Harvey was dead before Hooke, Malpighi, Swammerdam, or Leeuwenhoek, the fathers of microscopy, began their work. He saw the circulation in shrimps "ope perspicillo " indeed — but the perspi- cillum was a mere handglass. Hence it is not wonderful that Harvey's theory of fecundation is altogether erro- neous : and that he is no less mistaken respecting the nature of the parts of the embryo which first make their appearance and the mode of their formation. Nevertheless, just as it is the fate of dulness to be blind to the significance of justly observed facts, so is it the rare privilege of men of the highest genius to discern the true light among the ignesfatui of error. They know the truth, as Falstaff discerned the true prince among his pot companions, by instinct. Explain the matter how we will, it is an indubitable fact that though Harvey's fundamental observations were either inadequate or erroneous, some of his most important general conclu- sions express the outcome of modern research. For a whole century Harvey's successors, even though the illustrious Haller was among them, went wrong when Harvey was right ; and though Caspar Wolff returned to Harvey's views and thereby laid the foundation of modern embryology, the definitive triumph of the doc- trine of epigenesis is the result of labours which have been effected within the memory of living men. Such appear to me to be the chief claims of Harvey to be held in everlasting honour among men of science. We know that they represent a mere fraction of what he did. But the violence of an unhappy time has robbed u& of the rest. I should trespass unwarrantably on your time if I insisted on the apphcations of Harvey's disco- veries to medicine and surgery in the presence of those whose daily avocations bear witness to them. June 6, 1878] NATURE 147 I have hitherto dwelt upon the claims to our honour of Harvey the philosopher ; one word, in conclusion, concerning Harvey the man. There have been great men whose personality one would gladly forget : brilliant capacities besmirched with the stains of inordinate am- bition, or vanity, or avarice ; or soiled by worse vices ; or men of one idea, unable to look beyond the circle of their own pursuits. But no such flaw as any of these defaces the fair fame of William Harvey. The most that tradition has to say against him is, that he was quick of temper and could say a sharp thing on occasion. I do not feel disposed to cast a stone against him on that ground ; but rather, such being the case, to marvel at the astonishing, not only self-control, but sweetness, displayed in his two short controversial writings — the letters to Riolan ; a man who really was nothing better than a tympanitic philistine, and who would have been all the better for a few sharp incisions. Moreover, in such a temperament, while the love of appreciation is keen, the sense of wrong at unjust and wilful opposition is no less strong. But I do not recol- lect, in all Harvey's writings, an allusion to the magni- tude of his own achievements or an angry word against his assailants. Ready to welcome honour if it came, but quite able to be content without it ; caring little for anything but liberty to follow in peace his search into the ways of the unfathomable cause of things — " sive Deus, sive Natura Naturans, sive Anima Mundi appelletur"^ — one fancies this man of the true Stoic stamp would have summed up his eighty years of good and evil in the line of the poet, which Avas the favourite aphorism of his great contem- porary, Descartes — " Bene qui latuit bene vixit." But he lived too well that the memory of his life should be allowed to fall into oblivion ; and we may hope that recurring centennial anniversaries will find our succes- sors still mindful of the root from whence their ever- widening knowledge has sprung. After this Mr. Lowe replied in his usual racy style to the toast of the Universities, naturally having a little fling at the aspirations of Owens College and other recent institutions. Mr. Lowe remarked that anything like competition among the persons who conferred degrees and honours must be productive of evil. The result of such a system had been a kind of Dutch auction of degrees and honours, there being in some quarters a desire to secure as many students as possible by lowering the standard of qualification ; but he was happy to think that that evil was about to be remedied, and that they were approaching a time Avhen they would obtain what not only the medical profession, but every individual in this country had a right to demand, namely, that no one should be allowed to heave the lead into the depths of his fellow creature's physical constitution without possess- ing a certain proved degree of skill. That had been the dream of all sound medical reformers for a long time. It had hitherto remained only a dream, but as he had indi- cated, it was about to be realised, and he was bound to say that, as far as he understood the question, it was about to be so mainly through the noble and disinterested conduct of the universities, who, instead of displaying selfishness, had expressed their readiness to surrender the privilege they now enjoyed of admitting persons to the medical profession, and to hand over this duty to a certain body possessing the power of fixing a standard of qualification below which no person whatever should be admitted to practise. Mr. Gladstone, in responding to the toast of " General Science and Literature," said — Great as had been their profession in former times, every one must feel that it was growing greater, wider, more solid from year to year and from generation to generation. He did not speak now of ' " Exerci'atlones de Generatione," Ex. 50. literary culture ; for although he felt that literature had stood in a very important relation to the medical pro- fession of late years, still literature was necessarily fluctuating, and had been so in all periods of the world. They had gone through a great literary age, as other races had done before, and they could hardly expect the succeeding generation to maintain the same literary level. But as regarded science the case was very differ- ent. Nothing here seemed to be required but that patient labour which it was in the power of all men to bestow, together with those large opportunities for observation which we all enjoyed in some degree if we would but use them, and which medical men perhaps enjoyed in a greater degree than any other class of men. As society was developed, as civilisation became more elaborate, as the wants of men, as the enjoyments of men, and as, perhaps, also the dangers of men multiplied, and as the connection of body and mind, which was daily under their eyes, became revealed, they would find their way more and more into the very innermost chambers, so to speak, of human nature. As science progressed their re- sponsibilities would increase, but he was sure they would never be wanting in that capacity and zeal which had ever distinguished them, and that in proportion as their in- fluence over human welfare and human happiness in- creased, they would obtain that respect and gratitude which, amid their imperfections, mankind were ever ready to extend to their benefactors. OUR ASTRONOMICAL COLUMN The Transit of Mercury. — Unfavourable weather appears to have very generally interfered with obser- vations of the first contacts in the transit of May 6, in this country, and in France a similar adverse state of atmospheric conditions also prevailed. ' At Antwerp, Christiania, Gottingen, Josephstadt (Vienna), Kiel, and San Fernando (Cadiz), the contacts were observed and the results have been mostly published in the Astrono- mische Nachrichten. In two cases only is there any distinction made between what has been called geometrical contact, when Mercury appears perfectly round and his outer Hmb in coincidence with the sun's limb, and the instant when a fine filament of light is perceptible (or a connecting ligament is broken) which more correctly distinguishes the true internal contact. Thus at Kiel the time was noted when the planet appeared round and when the narrow luminous thread {detitlicher Lichtfaden) appeared. But the most complete observations of the first contacts hitherto printed are those made at the Observatory of San Fernando, near Cadiz, which are detailed in a circular issued on May 8, by Seiior Cecilio Pujazon, the director of the establishment. Amongst the observers were Sefiores Garrido and La Flor, who had also experience in the case of the transit in November, 1 868, at the same observatory, and with the same or very similar instruments, achromatics by Troughton and Simms of 80 mm. aperture. Three of the observers distinguish between what is termed " first internal con- tact" and separation of the limbs {desprendimiento de los limbos), the mean interval noted between the two phases being 18 seconds. At Palermo the contacts were noted both with the spectroscope and on the ordinary telescopic method. Prof. Tacchini communicated the particulars to the Paris Academy of Sciences on May 20, at the same time stating that he had been informed of the ill-success attending the observation of the transit at Naples, Florence, Venice, Gallarate (Baron Dembowski' s observatory), Genoa, and Modena, on account of unfavourable skies. In the United States the phenomenon appears to have excited a very unusual degree of interest, occasioned, no doubt, by the instructions for observing it widely- circulated by the authorities of the Naval Observatory, 148 NATURE \June6, 1878 Washington, and the presence in the country of a special expedition composed of French astronomers. Judging from the accounts published in the New York papers on May 7, observations were more or less successful in many astronomical institutions, both the first and last contacts being generally well observed, and numerous photo- graphs obtained during the passage of the planet across the sun's disc. At Ogden, Utah, where the French astronomers were located, the clouds prevented more than imperfect observations of the first contacts ; but those at egress were satisfactory. Up to one o'clock only three photographs were obtained, but subsequently as many as seventy-five were secured, and the results, as a whole, were considered satisfactory. At the observatory of Dr. Draper, Hastings, on the Hudson, a number of observers, including Prof. Holden, of Washington, availed themselves of the admirable instrumental resources, and the weather being for the most part advantageous, very good results attended their efforts : of eighteen negatives taken by Dr. Draper several were particularly perfect. In addition to observations at the U.S. Naval Observatory Prof. Newcomb and assistants made satisfactory ones at the office of the American Ephemeris in Washington, noting the first internal contact at loh. 7m. 43s. a.m., according to the New York Times, and the second internal contact at 5h. 53m. 50s. P.M. The following differences between the calculated and observed times of first internal contact have been ob- tained by comparison with Leverrier's elements, with Newcomb's value of the solar parallax; the Greenwich mean time for the centre of the earth resulting from a calculation of somewhat greater refinement than that previously introduced in this column being 3h. i6m. I2*5s. Observed Place of G.M.T. Error of Observation. reduced to Calculatk n. earth's centre, h. m. s. s. Antwerp 3 15 46*0 + 26'5 Two observers. Christiania — 41*2 + 3i'3 " Apparent internal contact." ,, — 52*9 . + 19*6 " True internal contact." Gottingen — 34'8 + 377 Prof. Klinkerfues. ,, — 47*7 + 24*8 Boedclicker and Heidorn. Josephstadt — 48-5 + 24*0 Three obsei-vers. Kiel — 38'6 + 33^9 Planet round. „ — 53*3 + i9*2 " Deutlicher Lichtfaden." Palermo — 55-9 + i6"6 Spectroscope. ,, — 46*1 +26*4 Ordinary telescopic method. SanFemando — 49-1 + 23*4 Geometrical contact. ,, 3 16 1 1 "7 + o"8 Separation of limbs. _,,,.. „ ( Prof. Newcomb and assis- Washmgton 3 15 58-4 + 14-1 j ^^^^^ The Greenwich mean time of second internal contact similarly calculated is loh. 43m. 57 'Ss., which, compared with Prof. Newcomb's observations at Washington, shows a difference of 4- I9'6s. Other observations of the second internal contact given in the New York journals are either provisionally reduced or apparently affected by typogra- phical errors or errors of transmission. The Zodiacal Light and Sun-spot Frequency. — In a letter addressed to Gruithuisen in February, 1839, published by the latter in his Astronotnisches Jahrbuch for 1840, Olbers remarks, "My grandson, Wilhelm Focke, Doctor of Law, who with attachment and zeal often contemplates and scrutinises the starry heavens, asserts that the zodiacal light has been observed in January and February with quite exceptional brightness;" which, Gruithuisen observes in a note, is "a new confirmation of Cassini's observation that the zodiacal light is much more brilliant when numerous and large sun-spots are present, and diminishes in brightness when the spots are few» My observations show that during January and February the sun has exhibited unusually large and numerous spots," and he adds, "viel Licht und fast immer eine grosse negative Refraction." This refers to Cassini's con- cluding statement in his memoir entitled " D^couverte de la lumi^re celeste qui parait dans le Zodiaque." " It is a remarkable circumstance that since the end of the year 1688, when this light began to grow fainter, spots have no longer appeared in the sun, while in the preceding years they were very frequent, which seems to support in some manner the conjecture that this light may arise from the same emanations as the spots and faail(z of the sun." In a previous part of the memoir Cassini, endeavouring to assign a possible cause for the appearance of the zodiacal light, remarks that the observations of that century had made known that the sun is not only the source of light, but also of " une mati^re propre k terminer, k ddtourner, et k rdflechir ses rayons;" and that "cette mati^re ne coule pas toujours de la meme mani^re, mais qu'elle a des vicissitudes sans r^gle, selon lesquelles nous voyons en certain temps dans son disque des facules, qui sont plus Claires que le reste de la surface, et des taches obscures qui ne sont point pdndtr^es par sa lumi^re." And he goes on to say that if the matter which is the subject of this light is of the same nature as that which forms ihe/aael(z and spots on the sun, it should be liable to the same changes and irregularities. However inadequate or incorrect is the explanation of the spots and faculae given by Cassini, his conjecture that the brightness of the zodiacal light varies with the number and magnitude of the solar spots is worthy of note, though we do not re- member to have seen any allusion to it in our popular astronomical treatises. THE INTERNATIONAL GEOLOGICAL CON- GRESS THE time of the opening of this Congress in Paris has been finally fixed by the local committee for the 29th August, and the Congress will remain in session about two weeks. Further details as to organization and place of meeting will soon be made public. Meanwhile, it is announced that from the 20th August to the 15th September, the library and reading-rooms of the Geolo- gical Society of France, No. 7, rue des Grands-Augustins, Paris, will be at the service of members of the Congress. As before, it is requested that all those who desire to take part therein will make it known to the general secretary, Dr. Ed. Jannetaz, at the above address, where, also, the subscription of twelve francs, required for each member, may be sent to Dr. Bioche, treasurer. Ladies are admitted to the Congress. The local committee add to the above announcements : — There is reason to believe that the numerous collec- tions of geology and palaeontology, minerals, rocks, fossils,J maps, sections, plans, models in rehef, &c., to be found in the Exposition Universelle, will realise the expectations expressed in the circular of the Inter- national Committee, of an International Geological Exhibition. All exhibitors of such collections are re- quested to send, as above, such lists as will enable the secretary-general, Dr. Jannetaz, to prepare a special catalogue of them for the use of the Congress. T. Sterry Hunt, Secretary of the International Committee A KINEMATICAL THEOREM TAKE a plane, and, for clearness of idea, consider it as fixed horizontally. On this fixed plane lay another, and throughout the subsequent movement let the surfaces of the two planes always remain in contact. Now let the upper plane, starting from any position, be moved about in any manner whatever, making any number (A/') of rotations, the points on it describing curves of any desired degree of complexity on the lower plane ; and let it finally settle down again into its initial position, the curves described by* the points on it being, in conse- quence, closed curves. Take the upper plane, and let us investigate the position on it of those points which have described curves of any given area {A) on the fixed plane. y line 6, 1878] NATURE 149 However complex the curves described by them may be, the points will be found to form a circle on the upper plane ; and if we give to A different values, the corre- sponding circles will be found to be all concentric. Further, if we call the circle corresponding to the value A = o the zero-circle, the area of the curves described by the points on any other circle of the system equals N times the ring inclosed between that circle and the zero- circle. It is remarkable that such a singular point as the centre of the circles should exist. In the special case in which N=o, i.e., where there has been only an oscillatory movement of the upper plane and no complete rotation, the system of concentric circles is replaced by a system of parallel straight lines, the area of the curves described by the points on any straight line of the system being proportional to the distance of that line from the zero-line. It should, perhaps, be pointed out that the area of a figure 8 is zero, as the two halves are of opposite signs ; also that when a point reciprocates on a curve the area inclosed by it in its path is zero. For example : if we take the interesting case of a circle rolling inside another of twice its diameter, every point on its circumference reciprocates on a straight line, and consequently the circumference is the zero-circle. This theorem was suggested to me by reading a paper by Mr. C. Leudesdorf in the Messenger of Mathematics, where I have already enunciated it. It seems, however, to be one which, from its somewhat startling simplicity, may interest a larger class of readers than a purely mathematical one. The proof is simple. Let P, F be two points on the moving plane, and let A, A' be the areas described by them. Let P P = r, and let the total movement of P' perpendicular X.o P F — n. Then A - A'= nr + Nir r\ If we take F as origin and the position of P' P in which 11 is a maximum and equal to n as initial line, n'=ncos 6. Thus A—A'=ti'co~>&' r-\-NTTr\ the equation to a family of concentric circles. Transforming to the centre, we have A = NiT{r''-a% where a is the radius of the zero-circle. A. B. Kempe OLD MAPS OF AFRICA TV/TR. STANLEY, in the paper which he read at the ^^^ Geographical Society on Monday, spoke of Africa being brought to light after an oblivion of 6,000 years. Notwithstanding the somewhat confused phraseology, Mr. Stanley's meaning is clear enough : Central Africa, with its great lakes and rivers, is now known, he means to say, for the first time. But recent investigation seems to show that the oblivion of Africa must be counted by hundreds and not thousands of years ; that, in fact, it is only within two or three centuries that a knowledge of Central Africa has been allowed to lapse. A more rigorous search may show that between the fourteenth and the seventeenth centuries the great features that have been placed on modern maps within the past few years were discovered and recorded on the maps of the time. We have recently referred, on more than one occa- sion, to two very curious globes that have been brought to light, one in the National Library in Paris, and the other in the Library of Lyons. On the Lyons globe, the date of which is 1701, the Congo is made to issue from a great lake, and wind its way westwards to the Adantic, in a direction to some extent coincident with that recently discovered by Mr. Stanley. As a sort of preparation for the work of the great traveller, so soon to be issued,- some account of the data on which these maps may have been constructed, may not be uninteresting. Our information is based on an article in La Nature, and on a report by a commission of the Lyons Geographical Society, ap- pointed to investigate the value and origin of the Lyons globe. The discovery made at Lyons is, in reality, no surprise to those who know the history of geographical exploration. Not only in the seventeenth century, does the Zaire- Congo appear on most of the maps with the direction definitely assigned to it by Stanley, but nearly all old documents, from the fifteenth century— and the date should be noted — make the great river issue from a con- siderable mass of water far in the interior of the African continent. Already, in the year 1500, the famous mappemonde of Juan de la Cosa, the pilot of Christopher Columbus, gives the same indications ; the picturesque mappetnonde known as that of Henry II., repeats them with some variations, as also the master-work of Mercator (1569), the founder of modern geography. All the old geo- graphers, or nearly all, repeat the same data : — Forlani (1562), Castaldi (1564), Sanuto (1588), Hondius (1607), Nicolas Picart (1644), Bloeu (1569), Sanson, &c. There- fore there need be no surprise to find on a globe of the eighteenth ceutury information which for more than 200 years previously had been registered on the map of Africa. Whence, however, came this knowledge which our fathers had of certain regions in Central and Equatorial Africa ? The reply is simple ; from the Portuguese, who, since the fifteenth century, undertook not only extensive maritime voyages, but several times crossed Africa from west to east and from east to west. It is even very pos- sible that they discovered the sources of the Nile, the great equatorial lakes ; thus, in the midst of the simplicity and incoherence of their tracings we find, in their old parchments, the great lines of African geography almost as science now represents them. Most of these Portu- guese, with the exception of some missionaries, were but poorly educated ; they travelled much oftener as traders than as experienced explorers ; nevertheless, we have almost the certainty that before the year 1500 they had furnished very precise information on the centre of Africa. In nearly all these maps, and in that of Lyons, the Congo flows in a nearly straight line from Lake Zaire or Zembre to the Atlantic ; it bends only a very little to the north, and does not pass the equator, as we now know it does. As a sort of exception, there has been found among the riches of the National Library at Paris, a Spanish globe of copper (without date, but probably between 1530 and 1 540), which is not content with presenting the same data, but which reproduces, with wonderful closeness, the course of the Congo as discovered by Stanley. The river issues from a lake, flows towards the north, de- scribes a large curve well to the north of the equator, then turns west-south-west to the Atlantic. This is indeed a summary of the last journey of the intrepid American correspondent. Fig. i gives a perfectly accurate idea of a portion of this valuable globe. From all this it must not he concluded that Stanley has discovered nothing new. These discoveries of the ancient travellers, if genuine discoveries they were, seem to have ben forgotten as soon as they were recorded ; and although the maps referred to above have been known for generations, no one ever seems to have taken them as trustworthy guides to the lines of African exploration. Indeed, it is only now that Stanley has made a discovery never to be forgotten that these old maps have come to have a real interest, for we suspect that till now geo- graphers regarded the tracings as having their basis in the cartographers' imaginations. The glory of being really the first discoverers of the two Nyanzas, Nyassa, Tanganyika, Bangweolo, and the course of the Congo cannot be taken away from Speke and Baker and Burton and Livingstone and Stanley ; or if so it must be by some ancient Arab or possibly Egyptian, many, many centuries ago, for there can be no doubt that long before Europe I50 NA TURE \yune 6, 1878 awakened to modern geographical enterprise, these great features of Central Africa Mere known ; Herodotus had an inkling of them, and Ptolemy all but located the cen- tral lakes. These modern explorers deserve the glory of first discorerers as much as Columbus deserves that of discoverer of America. Without then detracting from the originality of the work of modern explorers, it is evident that from the fifteenth century onwards some travellers whose names have fallen into oblivion but who may have been com- panions of Diego Cam and Martin Behaim, ventured into the heart of Africa; followed certain arteries of com- munication and discovered the course of the Congo ; geography kept posse'ssion of these discoveries for two centuries and gave them as articles of faith ; besides, in the sixteenth and seventeenth centuries many Portu- guese, Capuchins or simple traders, entered anew the interior, published the same facts, sometimes with cor- rections and additions. Father Ricioli, a Jesuit and very intelligent man, furnished the Fathers Placide, of St. Amien, and Cres- pinien, two laborious monks, with documents to prepare the Lyons globe, in 1701. The actual constructor of the globe seems to have been the celebrated Lyons me- chanician, Henri Marchand, in religion P^re Gregoire, a Franciscan, with the help of the Venetian Contarini, a pupil of Nolin, belonging to the Flemish cartographic system. Evidently this was the last word of science. Fig. 3 is a much reduced copy of the facsimile made from the globe by M. Deloncle, the reporter of the commission we have alluded to- How came it that just about the same time, about 1700, one of the princes of modern geography, Guillaume Delisle, was so badly inspired as to reconstruct an alto- FiG. I, — Portion cf a Spanish Globe of 1530-4O) found in the National Library, Paris. gether New Africa in which he accumulated heresy on heresy? The Central lakes, the immense reservoirs of the Nile, disappear at one stroke of the pen ; as to the Congo it is no longer connected with the lakes of the interior, although it is allowed to retain a little of its semicircular direction. The error accredited by a cele- brated geographer like Delisle made way. The old map of Africa was demolished stone by stone, so to speak. In short the work was so well done that, after having piled nonsense upon nonsense, for the sake of peace, all was expunged; after having believed in tribes with dog- heads, placed a few anthropophagi everywhere, and con- founded countries situated a thousand miles from each other, they ended by making a tabula rasa and leaving a white space where formerly were rightly placed the great lakes and sources of the Nile. Yet a few years and here was geography doubting, denying, and ridiculing the follies of our predecessors. The students of geography of the period of 1840-50 were too much on their guard to commit the colossal blunder at that period of making the Nile issue from the lakes to the south of the equator. "So far as concerns a part of Africa," to quote M, R. Cortambert, in the article in La Nature, "the past has been resuscitated : 'old things have become new.' That which was laughed at yesterday is taken seriously to-day. Then, my friends, these good ancestors of the fifteenth and sixteenth centuries, who counted among them Columbus, Gama, Magellan, and many other conquerors of the world, have not, perhaps, left altogether to their descendants of the nineteenth century the glory of invent- ing geography." From the report of the Lyons Commission we learn that the following works were probably accessible to the Flemish map-makers, and later to the constructors of the June 6, 1878] NATURE 151 Lyons globe: — i. The Geography of Ptolemy; 2. The " Portuguese Asia " of De Barros (1552); 3- The "De- scription of the Congo," by Pigafetta, according to Lopez (1592); 4. The " Historical Description of Ethio- pia" of Dom Francesco Alvarez" (1558); 5. The "Africa" of Leo Africanus (1556); 6. And the old maps and portulans. Among these old maps and portulans, those which appear at this period to have had a certain influence are : — i. The Medicean Portulan (1351); 2. The Catalan Atlas (1375); 3. The Map of Mecia de Viledestes (1413); 4. The Map of Johannes Leardus (1448) ; 5. The Mappe- monde of Fra Mauro ; 6. The Ambrosean Map (1480) ; 7. The Mappemonde of Juan de la Cosa (1500); 8. The Map of Diego Ribera ; 9. The Spanish Mappemonde of the National Library, Paris (Fig. 3) (1540); 10. The Maps of Ramusio, of Pigafetta, and of Hugues Lin- schoten. In the detailed report which the Lyons Commission will communicate to the Society will be shown to what extent each of the above documents contributed to the establishment of the Flemish maps, on which probably the Lyons globe was more immediately based. The same Report will contain an investigation into the travels known or unpublished which, from the tenth century, have contributed to the progress of the African geography of the Middle Ages and of the Renaissance. This inves- tigation will include the following : — i. The Arab voy- ages and Compendia ; 2. The voyages of the mendicant Spanish friar of the fourteenth century ; 3. The expe- dition of eight dominicans of Montpellier to the sources of the Nile (1317-1350), unpublished; 4. The travels of Fig. 2. Fig. 3. Fig. 2. — Map o£ Stanley's Recent Journey Across Africa. Fig. 3.— Portion of a Globe of 1701, belonging to the Lyons Library, from a copy by M. Deloncle. the brothers Vivaldi, thirteenth century ; 5. The expe- dition of the Catalan Ferrer in 1346, unpublished ; 6. The voyages of Diego Cam; 7. The itineraries of the ^2ix\y pombeiros J 8. The " Eastern Ethiopia " of Joandos Santos ; 9. The travels of Barbosa ; 10. The exploration of the Dutch Jan ran Herder, in the country of the Akkas, unpublished; 11. The Derrotero desde Lisboa Al Cabo de Bueno Esperanza y India Oriental, anony- mous and unpublished; 12. The description of the Congo, by Martinus Abarca de Bolda et Castro (1601), unpublished ; 13. The " Universal Book of the Navi- gations of the World" (1590?), Spanish, unpublished ; 14 ; The Travels of the Belgian Pierre Fard^ from Algiers to the Congo (1686), unpublished ; 15. The "Travels of Manoel Godinho" (1663); 16. The Letters of Father Mariano, the Jesuit, on Kaftraria, &c., &c. The work undertaken by the Lyons Geographical Society is creditable to them in the highest degree atid will result in a valuable addition being made to historical geography. Their work, as the Commission rightly maintain, is to some extent international, and deserves the countenance and assistance of geographers all the world over. COSMIC METEOROLOGY^ IL /'NFL UENCE of the Moon on the Earth' s Magnetistn. — There is a fact in connection with the moon's influence on our earth for which an explanation is necessary, and M. Faye has proposed for this end a hypothesis in advance. He had already pointed out Dr. Lloyd's investigation which showed that the diurnal magnetic variations could ' Continued from p. > 28. 152 NATURE \ywie 6, 1878 not be explained by the hypothesis that the sun acts as a magnet. But, it is said, " May the moon not acquire induced magnetism under the action of the earth, per- petually variable according to the relative position of the two bodies ? If we consider the enormous magnetic power of the earth, that Gauss finds equal to that of 464 trillions ' of magnets weighing a pound each, and if we remark besides that the distance of the moon to the earth does not exceed thirty times the length of this gigantic magnet, we may give an affirmative answer to the question proposed. But then the magnetism induced in the moon should in its turn exercise a small action upon the proper magnetism of the earth in the period of a lunar month. The observations alone can decide this provided they are of great precision." M. Faye then cites the results obtained from the Toronto observations by Gen. Sir E. Sabine, that for the magnetic declination showing a range of o'"64; and he adds, "All these effects are of double period; they show two maxima and two minima in the course of the lunar month of 29^ days, which proves that they are due to an induced or reflex action, not to a direct action of the moon herself." I shall put my remarks on this sub- ject under three heads. 1. Is such a result possible for the moon's synodical revolution ? Let us commence with full moon at the winter solstice ; near this epoch the moon is in the plane perpendicular to the ecliptic passing through the earth's magnetic axis and the sun. The north pole of the ter- restrial magnet is then presented to the moon in such a way as to produce the maximum of induction ; when the moon is near her third quarter the two terrestrial mag- netic poles will be equidistant from the moon and the inducing action will be a minimum ; there will be a second maximum near new moon when the south pole is most presented to our satellite and a second minimum near the first quarter. If now we follow the earth in her revolution to the vernal equinox, we shall find all this changed. At full moon our satellite is then equidistant from the two terrestrial poles, and the inducing action is a minimum ; it is a maximum, on the contrary, near the first and third quarters. The consequence will be that if any inducing action existed it would have the same value at all ages of the moon in the mean of observations made during a series of years, such as were employed by Sabine for the variations in question. Such a result, however, as has been imagined by M. Faye might be possible if, instead of the synodical, we employ the tropical revolution of the moon, which occupies nearly 27*3 days. 2. We may inquire, then, if the moon as a permanent or induced magnet can produce any magnetic variations appreciable by our instruments ? In the first place, Mr. Stoney has shown that if the moon were as magnetic bulk for bulk as our earth, her whole action in deflecting a freely-suspended needle in our latitudes, could not exceed one-tenth of a second of arc (o""i).* In order to consider the question of the variable magnetism induced in the moon by our earth, let us suppose her inductive capacity equal to that of cast-iron. From Barlow's experiments at Woolwich with iron balls I find that the magnetism induced in an iron ball of one foot diameter is about 2'o, in English units, which is nearly twice the magnetic force given by Gauss for the same volume of our earth. Barlow found the induced moments of different balls to vary as their volumes, and assuming that the induced magnetism varies inversely as the cube of the distance of the inducing and induced bodies, we find at the moon' s distance (60 terrestrial radii) the induced magnetism at the maximum, under the most favourable condition, could not be more than ^, = — :; of that supposed in the first case, 60^ 108,000 ' M. Faye uses the word trillions, but the trillions are English, not French, the latter being a very different number, a Pkil. Mag. , vol. xxii. p 294. that is when as magnetic as the earth. Her whole action on a magnetic needle here, then, due to the earth's induction, could not exceed one millionth of a second of arc. It is advantageous to get rid of hypotheses which are so completely insufficient, and we may put aside for the future any consideration of the moon's action by her own permanent magnetism, or by a variable magnetism induced in her by the earth. 3. M. Faye has also misunderstood the facts which he wished to explain. The results obtained by Sabine have reference to a variation which occurs in 24I hours, the lunar day, and not the lunar month of 29^ days. The laws of the lunar diurnal variations were obtained first by Kreil for the magnetic declination, and by myself for the magnetic force and inclination. This action of the moon is, however, so very different from what is generally sup- posed, and from what was concluded from the first investi- gation on the subject, that it is of the greatest import- ance, in relation to the whole question of cosmic meteoro- logy, I should state some of the more marked facts which have been deduced from eleven years' hourly observa- tions on the magnetic equator. I shall limit myself at present to the lunar actions on the direction of the horizontal magnetic needle. The moon, in a lunar day of 247 hours, produces a variation in the earth's magnetism, such that the mag- netic needle makes two complete and nearly equal oscilla- tions from an easterly to a westerly position in the interval in question. This is the general 7}iean law. We have seen, in considering the law of the solar diurnal variations that, near the magnetic equator, the la\y^ becomes reversed when the sun passes from the one hemisphere to the other, so that when the sun is north, the movement of the needle is like that in high north latitudes, and when south, like that in high south lati- tudes. If, then, the moon acts in the same way as the sun, we should expect a similar phenomenon for the lunar diurnal variation when the moon crosses the equator. This is not the fact. The law differs little for the position of the moon north and south of the equ.itor. There is, however, an inversion of the lunar diurnal oscillations ; thus, in the months of December and January the north end of a magnetic needle is farthest east when the moon is on the upper and lower meridians, and farthest west near moon-rise and moon-set ; whereas in the months of June and July the reverse is the case, the north end of the needle being farthest west when the moon is on the meridian (upper and lower) and farthest east when she is on the horizon. It followed from this, as for the solar diurnal law, that the oscillations should be in opposite directions at the same time in the higher latitudes of the two hemispheres, as has been found to be the case. It is not then when the moon crosses the equator but near the times when the sun does so, that the moon' s action is reversed. The dependence of the lunar action on the position of the sun becomes more evident as the investigation becomes more detailed. When we determine the mean law for each month of the year, we find that the north end of the needle moves equally far east and equally far west at each of the two oscillations in the lunar day ; this is not found to be the case for different positions of the moon relatively to the sun. Thus in the quarter lunations including full moon, in the months of December and January, the greatest west-east-west oscillation of the needle occurs when the moon is on the lower meridian ; not when the moon, but when the sun, is shining on the place of the needle. The oscillation from moon-rise to moon-set, that is to say, while the moon is above the horizon, is little more than one-third of the oscillation for the half day when she is below the horizon ; the two westerly extreme positions when the moon is on the horizon are nearly the same. June^, 1878] NATURE 153 Similar results are obtained for the other quarter luna- tions. In all cases that oscillation is the greatest of the two for which the sun is above the horizon, whether the moon be above it or not. There are still some remarkable facts connected with this variation at the magnetic equator. Limiting our examination of them always to December and January, we find, if we determine the oscillations due to the moon for the day when she is in conjunction and for each of the six following days, that in the first three days of the seven the oscillation is west-east-west during the day, that is, from sunrise to sunset ; and in the last three days it is east-west-east. In the middle day of the seven the lunar action is almost null ; the oscillation of the needle is very small, as we might expect, since on that day the change at sunrise from a west-east to an east-west motion takes place. The lunar hours of the maximum and minimum extremes thus oscillate about two hours on each side of the mean, depending on the position of the moon at sunrise. The action of the moon, then, is dependent on the sun's position relatively to the equator (or the earth's position in its orbit), and on the position of the moon relatively to sunrise and sunset. But there is no rela- tion between the laws and amplitudes of the solar and lunar diurnal oscillations. In the months from which I have taken my illustrations, the solar diurnal variation is a single oscillation : that for the moon, however taken, for single days, for quarter or for whole lunations, is always double. Through the combination of all the varying modes in which this oscillation is produced from day to day, the mean for a lunation is a regular double oscillation. The amplitude of this mean oscillation is three times as great in January as in June or July ; whereas the amplitude of the mean solar diurnal varia- tion is a half greater in June or July than in January. I shall add another fact, one of the greatest im- portance in connection with this subject. We have seen that the lunar diurnal variation changes in the relative amplitudes of the two oscillations from day to day ; the consequence of this is that when the means for a whole lunation, or even a quarter lunation, are taken, the mean amplitude is much less than that which is shown by each day separately. Thus I have found that the range of the mean lunar diurnal oscillation for the lunation December 16, 1858, to January 15, 1859, ^'^ Trevandrum, was i''25, while the ranges of the mean oscillations for the quarter lunations varied from \'"jo to 2'7o, these quarter luna- tions giving exactly the same laws as have been deduced from eleven years observations for the same lunar epochs. In order to understand the value of these results we must compare them with the ranges of the solar diurnal oscillations for the same months ; those for December, 1858, and January, 1859, were 2' "20 and 2''24 respectively. And as on some days the lunar diurnal variation has amounted to nearly 5''o (which is equivalent to 12' in England with the smaller directive force), it appears that the lunar action is sometimes greater than the solar action at the magnetic equator. As long as the lunar diurnal action was considered to be of the minute character first discovered, it was always possible for the supporters of the heat thesis to suspect that some small unknown heat action was in question. Such an idea is no longer possible. The lunar is some- times greater than the solar diurnal action ; and the former is dependent for its magnitude on the light and heat vibrations dtie to the sun shining on the place of the magnetic needle.^ If the solar light and heat vibrations can increase the magnetic action, there can be no difficulty in believing ' Mr. Willoughby Smith's experiments show that the light vibrations of the ether in selenium diminish in a very marked manner the electrical resist- ance of the crystal ; and it does not seem improbable that the increase of the lunar magnetic oscillation in sunlight may be due to some similar action. that these vibrations may in their turn suffer some modi- fication of intensity. It would be difficult to measure small variations of the sun' s light with sufficient accuracy as yet, though Mr. Willoughby Smith has suggested a selenium photometer for this end ; we can, however, measure the variations of temperature, and the fact that the direct heating action of the moon is inappreciable is no longer sufficient to disprove the results of Madler, Kreil, Park Harrison, and Balfour Stewart. We have in fact a mode of lunar action with which M. Faye was unacquainted and could not take into account. The whole basis of his argument is therefore destroyed. The view now given opens up a wide field of inquiry, and cosmic meteorology appears under another aspect. I hope to be able at another time to present other facts which seem to relate to magnetical and meteorological phenomena. John Allan Broun THE NUTRITION OF BROS ERA ROTUNDI- FOLIA DURING the summer of 1877 I began an experiment, the results of which were given in a paper read before the Linnean Society, January 17, 1878. A number of Drosera Plants were freely supplied with meat, while another set were kept without animal food. At the end of the season the two sets were compared in various ways with the object of deciding whether or not carnivorous plants profit by an animal diet. In the abstract of my paper published in Nature (vol. xvii. p. 222), it may be seen how numerous were the advantages gained by the fed plants. The further results of the experiment are not without interest. The plants on Avhich I worked were cultivated in six soup-plates, and after all the flower stems had been cut, the plants in three of the plates were removed from the moss in which they grew, and were counted and weighed. The plants in the other plates were left undisturbed with the object of comparing the new plants which should spring up from the winter buds of the two sets in the following year. They were removed to the hothouse in the course of the autumn, in order that they might rapidly send up the next year's leaves. By the middle of January, 1878, it became quite clear that far more leaves were springing up from the winter buds of the plants which had been fed than from the others. Both sets of plants were now kept without food, and on April 3 they were removed from the plates, and carefully counted, dried, and weighed. The following numbers give the result of the examination : — Actual numbers and weights. Proportion between two first columns. Not fed. Fed. Not fed. Fed. Number of plants 89 105 100 118 0 Total weight grams. •206 grams. •518 100 251 '6 Average weight per plant •0023 •0049 100 213*0 i It will be seen that there is only comparatively a small difference (18 per cent.) between the number of not-fed and fed plants. Numerous minute offsets were found among both sets, and were all counted as separate plants- But, judging either by the total or average weights, no doubt can be entertained of the great advantage gained by the fed plants. It is a striking fact that, in spite of the far larger yield of flower stalks, seeds, &c., produced during the previous summer by the fed plants, they were nevertheless enabled to lay by a far greater store of reserve-material than their not-fed competitors. 154 JS/ATURB [Jtmee, 1878 It is a curious coincidence that while I was at work on Drosera, an almost identical research was being conducted in Germany. The experiment of Drs. Kellermann and von Raumer were described before the Phys. Med. Society of Erlangen in July, 1877, and the final results were communicated by Rees, of Erlangen, to the Botanische Zeitung, April 5, 1878. The research was evidently conducted Avith extreme care, and it is very satisfactory to me to find that my results agree (speaking generally) with those of Kellermann and von Raumer. The plants used in their experiments were fed on aphides, and do not seem to have thriven quite so heartily as mine did on a meat diet. This appears from the following figures : — Number of flower stems Number of capsules Weigrht of seeds Kellermann and von Raumer's results. 100 : 152 100 : 174 100 : 20$ Mine. 100 : 165 100 : 194 103 : 380 In testing the relative powers of the fed and not fed plants in laying by reserve-material in the winter buds, the Erlangen observers adopted a more accurate method than mine, namely, that of weighing the winter buds, instead of waiting until the new leaves had grown. They found that the weights of winter buds for the fed and not fed plants were as 173 : 100. FRANCIS Darwin PHYSICAL SCIENCE FOR ARTISTS ^ V. THE simple and forcible language employed by Prof. Stokes in the extract I gave in my last paper, should have made it quite clear that in nine cases out of ten, when bodies reflect light to us, they have really absorbed a part of it in the process, and that to this absorption of light bodies by their colours are chiefly to be ascribed. Those bodies which give back to us light in the middle of the spectrum — light, in other words, containing green and yellow — are those which are most liable to change with different intensities of light. I shall endeavour, if I have space, to return to this point in the sequel, but I feel that my first duty, now that the phenomena of ab- sorption have, I trust, been clearly explained, is to pass on to the application of this knowledge to the various colours of the sky. Having, then, this idea of absorption, a very important consideration comes in : the absorption of a substance generally increases with its thickness, and when we deal with those substances that for a given thickness absorb either the red or the blue, we often find that when the thickness is considerably increased the absorption spreads over the whole spectrum from the blue or the red end respectively. This can be shown graphically as follows : — Blue Absorptioft. a [§ © V ® ^i'^'^or^" V Q © © V ® V I © © V © [^ V I B © "^ © [^ VI BGV © [g VI B G Y © [JS V I B G Y O [^ Here, then, we have an absorption beginning at the blue end and gradually closing everything except the red. I may remark en passaftt that we here have the physics of sunrise and sunset colours ; similarly we might begin at the red end and then we should get , W D ^ a w a w a © V © R ©¥ ©Y OR OR GYOR, and so on. ;w These effects may be experimentally observed by either using different thicknesses of the absorbing materials or by putting them into a V-shaped vessel, and observing the change which takes place when the light passes through the greatest and least thicknesses of the absorb- ing material. It is of importance also for the artist to observe the effect of the residual light independently of the spectral phenomena. For instance : if we take a chlorine tube of such a length that it begins to cut off the Lea«t thickness Pvt.usium permanganate. Chromx chloride. FiG.'i. — Showing phenomena of absorption produced by great and small thicknesses of the same substance in a wedge-shaped cell. blue the residual light will be a delicate green ; a tube twice the length will give us a colour in which the rich golden yellow predominates. Although we have been compelled to leave out several steps in the argument, we are in a position now to ap- proach the cause of the various colours of the sky. Let us assume that our complex atmosphere— complex because it consists of a mixture of two pure gases and aqueous vapour— absorbs the light which passes through it, and'that the absorptive effect depends upon the thick- ness o"? the atmosphere through which the light has to pass before it reaches the eye. Now there are many grounds for supposing that the Ccnt.nued from p. 126. Fig. 2.— Arrangement for observing the absorption of a great thickness of gas or liqu.d. L, lamp; N, tube ; s, spectroscope; g, bunsen burner when used. general absorptive effect both of the pure gases and of yu7ie 6, 1878] NATURE 15s the aqueous vapour is of the blue kind : that is to say* that the smallest thickness which has any visible effect ■will absorb in the blue. We also know that the absorp- tive effect of aqueous vapour is enormously greater than that of the pure gases. I feel bound to show at once that this is no scientific abstraction, and it would be impossible to find two better examples to show exactly what I mean than those afforded by two of the pictures which I have chosen as texts — Mr. Vicat Cole's " Rosenlaui " and Mr. Peter Graham's " Wandering Shadows." Whether I am right or wrong about the molecular states of aqueous vapour, there is no doubt that the quantity of it varies considerably. The clouds in Mr. Graham's picture show us that the air is charged with it, for the simple reason that if it were not there would be no clouds to cast the shadows Avhich he has so exquisitely caught. Look now at t'ne dark hill in the distance ; see how blue the air is between us and it — for it is true that it is the colour of the air, or rather of the aqueous vapour in the air, as Leonardo da Vinci first dis- covered, and not the colour of the hill which Mr. Graham here paints. We are in presence of aqueous vapour com- petent to be set in vibration by blue light, and because it vibrates in this way it appears blue. What would have happened if the dark hill had not been there ? If the stratum of aqueous vapour had had a background of bright sky, it would have absorbed the blue light of that sky. By virtue of the principles which I have stated, the sky would have appeared red in con- sequence of the abstraction of blue light. This, by the way. Turn now to Mr. Vicat Cole's picture, and see the work of the vapour upon each receding buttress of rock on the left of the valley; the depth of atmosphere is rendered to perfection, but we do not get the blue that Mr. Graham gave us, for the reason that there is less aqueous vapour mixed up with the air. Many an artist, I am sure, has noticed that at times there appears to be no atmosphere at all ; all sense of distance is lost ; buttresses such as those painted by Mr. Vicat Cole, although obviously, as may be gathered from the structure of the mountain, at different dis- tances from the eye, seem yet to lie in the same vertical plane. I saw this effect myself in its very strongest form last year at Cadenabbia. Looking eastwards from the hotel there, over the lake of Como, one sees Belaggio, the hills between Bellano and Lecco on the other side of what is called the Lecco leg of Como forming a magnificent background ; these hills recede from the eye in a magnifi- cent series of buttresses. Although some of these but- tresses were three or four miles oh the other side of Bellaggio, it was impossible to get rid of the feeling that lake, Bellaggio, background to the furthest buttress, was a painted canvas between us and the water. I called the attention of several friends to this wonderful sight ; they saw it exactly as I did. The explanation is quite simple : although the permanent gases of the air were there, the aqueous vapour was not, at all events, in that form which by its action on light gives us what artists call atmosphere in a picture. To me this afforded the strongest possible proof of the statement I have already made that the ab- sorption of the permanent gases of the air goes for nothing so far as art is concerned. As I have already hinted, the molecular form of aqueous vapour with which we have most to do is one, the motions of which lie chiefly at the blue end of the spectrum ; a small thickness of it cuts off the extreme blue, and as the thickness increases even the green may be dimmed by it. In order to show how on such a point as this, art, representing an accurate study of natural phenomena, may help science, I will here give the result of some obser- vations which my friend Dr. Schuster was good enough to make at my suggestion in the Himalayas and Tibet, with a view to test this very question. Theory had led me to expect that with the enormous thickness of air available there, absorption at the red end of the spectrum by aqueous vapour would be seen as well as the absorption at the blue, which is so common with us. Seeing the sun a vivid green through the steam of the little paddle-boat on Winder- mere first led me to inquire into the possibility of aqueous vapour following the same law as that which I think we may now accept in the cases of the vapours of metals. As in these experiments with vapours, absorp- tion of the red end alone was seen, as well as absorptioa at the blue end alone, the assumption that these two- absorptions existed in aqueous vapour at once accounted for the green sun, which, I may remark en passant, L caught again last year through a thin veil of mist at the extreme summit of the pass of the Simplon. Here, then, are Dr. Schuster's observations made at Simla when the rainy season had just begun : — June 27, 8 A.M. — B (one of the Fraunhofer lines at the red end of the spectrum), beautifully shaded. Light visible in the blue as far as 4040 ; most likely further ; but the telescope cannot be moved to greater deviation. 9 A.M. — Space beyond B closes up, while in the blue the spectrum is visible, as before. II. 15 A.M. — The red closed up still more; the blue as clear as before. 6.30 P.M. — Sun very near horizon ; spectrum seen from. C to G. (This means that both ends of the spectrum are now absorbed.) Dr. Schuster further states that he was at the same time struck by the fact that the peculiar redness of the clouds in the evening, which we observe so often in our climates, was only rarely seen, and, when seen, that the colour was rather yellow than red. He adds, "On making this remark to a friend competent to judge, and who, through a long sojourn in Simla, was enabled to form an opinion, 1 heard that the redness of the sky at sunset was often beautifully seen at the end of and after the rainy season." So much for the observations at Simla. I now pass on to some observations made in Upper Tibet, where there is no rainy season. I give them in Dr. Schuster's own words : — " The observations all point to the remarkable clearness in the blue. As I have said, the hygroscopic state of atmosphere, as measured by the wet and dry bulb or barometric pressure, cannot alone account for all the phenomena. I find, for instance, that the presence of vegetation affects the atmospheric absorption in a re- markable degree. In the Kyan Chu plain, for instance, the plateau on which I observed the mirage de- scribed in Nature, vol. xiii. p. 67, objects at ten miles distance look as sharp and distinct as those half a mile off; it is, in fact, impossible to judge of distance. Crossing the Tagalung Pass (18,000 feet), we descended from that plain into the Valley of the Indus. As soon as we reached vegetation, at a distance of only two marches from the above-mentioned plain, and at a height still above 12,000 feet, the whole aspect of the country is a different one. Distant mountains now take the lofty blue colour which gives such peculiar charm to the landscape. In the evenings, especially, you cannot help knowing that there is something between your eye and a distant object, which affects its colour and distinctness, and through it you get a standard for judging distances. Without vege- tation, even at a lower height, as, for instance, in the Valley of the Bagha (Lahoul), you seem to look through a vacuum. In the upper part of the Valley of the Indus, of which I am now speaking, I have not seen that clearness in- the atmosphere which I have invariably seen in Switzerland at a height of 3,000 feet. The strong radiating power of the sun, which stands much more vertical in India, is evidently the cause of this, for it can only be organic matter floating in the atmosphere which can produce such a 156 NATURE \June 6, 1878 striking result ; that the absence of any rain or deposit of any kind must not be left out of account is clear. The air in the side valleys of Cashmere, although rich in vegetation, is particularly transparent. Strange enough, the principal valley of Cashmere, i.e., the valley of the Jehlum, is generally hazy, although there is a good deal of rain. I have seen the planet Mars look almost white ; Jupiter and the other stars at that time had a bluish tint." I have been anxious to give these extracts not only because they form a valuable contribution to science, but because we see here the student of science doing what an artist is generally supposed to do, namely, interesting himself in the colouring of natural objects, and I cannot omit pointing this remark with the statement of my belief that when the artist attacks these also from the scientific point of view as well as the artistic one, his eye will lose nothing of its keenness, and his interest in the glory of nature will be nothing the less. Let us consider, then, the action of those molecules which absorb the blue light. Now since these molecules absorb blue light we know that they will reflect blue light, and, practically speaking, nothing else. Here, then, we have the cause for the blue colour of the sky. Those who are familiar with the brilliant researches of Dr. Tyndall on the action of light upon vapours will recollect that he also has arrived at a somewhat similar conclusion from a different line of reasoning and a different method of experimentation. To return one moment to oxygen and nitrogen, the gaseous constituents in our atmosphere, I must here remark that we have no evidence that the pure gases in our air change their molecular constitution; but we know that the aqueous vapour does to an enormous extent, and there is one state to which at present no reference has been made. There is a condition of aqueous vapour which is competent to absorb white light without giving rise to any coloured phenomena ; this is the form of which mist and clouds are built up ; why they are so dazzlingly white in the sunshine ; why we have a dark grey day absolutely devoid of colour when a pall of cloud hangs over the whole sky. In addition to this we know also not only that condi- tion to which I hare already referred, which absorbs in the blue, but certainly of one, and in all probability two which absorb in the red. One of these absorptions indi- cates that the form of vapour which produces it is of the most delicate kind, while that which gives us the continuous absorption in the red end is perhaps the last stage reached before clouds are formed. If this be so, the very complex nature of the true cause of sky colour will be obvious. We have three molecular colour-giving states to contend with, and the action of these will depend largely upon the thickness of aqueous vapour traversed by the sun- light. A diagram will at once explain how the action of these different thicknesses is brought about. In the diagram. Fig. 3, we have a section of a part of the earth and its atmosphere, supposing the latter to be somewhere between forty and fifty miles thick. On the assumption that the aqueous vapour, which, as I have shown, is the effective absorber in the air, is equally distributed, let us see how the question of thickness of absorbing layers comes in. Take an observer at 0, sup- posing him in the tropics, and that he sees the sun over- head at ^/notice the distance 0 a, which represents the thickness of air traversed when the sun is overhead, and compare it with 0 x, when the sun is rising or setting as at X, and when, therefore, the greatest thickness is traversed, taking no account of refraction. The whiteness of the sun at a high altitude and the red- ness of it when rising or setting is associated then with the fact that at these times the light traverses the least and greatest thickness of the atmosphere respectively ; an intermediate height of the sun is represented at F, and obviously the distance oy will vary for intermediate altitudes from 0 a to ox. Now the thinner we make our atmosphere the greater will be the difference of the thicknesses 0 a and 0 x, and, as a matter of fact, the effective aqueous vapour lies very low down ; so that the differences will be greater when we consider the aqueous vapour alone than when we consider the Avhole atmosphere. The thickness of the aqueous vapour, therefore, increasing from a to x, let us take the case of a perfectly clear sky at sunset ; the white light reflected, as I have already shown, in con- junction with the blue, will find itself most absorbed in the line ^ ;r, least absorbed in the Xvao. 0 a. In the line 0 X we get everything absorbed but the red ; we get, therefore, a red sky. A little higher everything is ab- sorbed but the red, orange, and yellow ; this will produce a rich golden colour above the red ; higher still, the green and part of the blue is allowed to pass ; in fact, only the extreme blue is absorbed; and, as I stated before, when I referred to the absorption of chlorine gas in a tube, the residual light will be green. Above the green we have the blue. This is the order of the colours of the sky ; the sun in consequence of its greater brilliancy can overcome this absorption until it has reached a very extreme limit, sunset clouds lighted up by the sun, therefore, mtist put on the colour of the sun, because the light which has reached our eye is red light, which has travelled to us vi& the cloud, hence the green is limited to a band of sky, between the gold and the blue, a green cloud is im- possible, and it is on this ground that I ventured to criticise Mr. Ellis's picture, "The Last of the Wreck," 555. Mr. Ellis has painted green clouds ; I am certain he never saw one in his life ; for a similar reason I have objected to Mr. Oakes's picture, "The Dee Sands." Sky colour is begotten by a low sun. I do not think that after what I have said it is necessary to point out how it comes that the blue clouds which Mr. Thornburn has chosen to paint are also impossible ; a cloud can only be of a colour which is got from the sun directly or indirectly. Now a blue sun is possible, but clouds illuminated by a blue sun are impossible in a picture, because for the sun to be blue there must be nothing but a thick veil of mist. I have drawn another diagram, which, although it looks rather complicated, may, I think, be rendered clear by a short description. The object I have had in view has been to show how the colours of the sky may be complicated after sunset. I believe in three pictures of sunrises or sunsets out of four, the phenomena presented have really been observed after sunset, in fact, in most pictures of sunset, the sun is a little too slow, we get sunset colour too soon. Juned, 1878] NATURE 57 In Fig. 4, ^X representing the direction of sunset or "sunrise," my object is to show that a cloud high up, say at x, when the sun has set so long as to be at s^ in- stead of at Xcan really receive light from the sun, and the distance xs" added to ox will represent the total amount of atmospheric absorption undergone by the light. It is Fig. 4. under these conditions, too, that, in consequence of the reduced illumination of the background, the sky puts on its most beautiful green, which I think is partly a physio- logical effect due to the molecular constitution of the retinas of our eyes. Similarly, by drawing a line from S^ we can see how a cloud absolutely in the zenith of the observer at o may have its colour transformed by a considerable atmospheric absorption after sunset. J. Norman Lockyer THE MICROPHONE IN SURGERY C\^ Tuesday at 3 P.M., before a crowded audience of ^^ students and medical men. Sir Henry Thompson gave a demonstration in the anatomical theatre, University College, on the microphone as applicable in operations for stone. In old days, the lecturer said, patients used to be sent away when they came to the doctor "because their case was not ripe.." The risk involved in the operation of cutting for stone was so serious that a surgeon seldom liked to undertake it except under com- pulsion, and Avhen cutting had to be resorted to it was not much more difficult to remove a large than a small calculus. In the newer operation of stone-crushing it was better, of course, to have the stone to be crushed as small as possible, and it was essential to deal with the smallest fragments to which the operation reduced it. It was often said, indeed, in objection to lithotrity that to leave even the smallest fragment as a nucleus was to render further treatment necessary and, in time, inevitable. However that might be, it was clearly important to be able to deal with the smallest calculus in the bladder. Before going further. Sir Henry Thompson emphatically stated that in his belief the present methods of lithotrity are quite sufficient in the hands of any surgeon of fair practice in the operation to enable him to deal success- fully at all events with almost every case. He compared the use of the new instrument which he was going to describe to that of the endoscope for the urethra, which, however satisfactory on paper, had not been found im- portant in practice, or, better perhaps, to that of the higher powers of the microscope, which were not necessary nor perhaps even advantageous in ordinary work, but which were a valuable resource in questions of unusual difficulty. The apparatus consisted of the ordinary feeble battery with wires, connected with two telephones i-unning to different parts of the room, and applied to the ears of the listeners. The ordinary Sound used in operations for crushing the stone was attached by a wire to the circuit of the battery. Near the handle a piece of carbon, such as is used by Prof. Hughes, was carefully balanced and attached by a delicate spring to the battery circuit. When the end of the sound strikes against the smallest piece of calculus the acoustic wave is transmitted along the steel of the instrument to the carbon, where it is transformed into electric vibrations, which are multiplied through the telephone, so that the noise becomes loud and unmistakable. But Sir Henry Thompson pointed out that m practice many things might interfere with the advan- tageous use of the instrument. The carbon arrangement on the soun-l must not be too delicate— not such, for in- stance, as could make us hear the walk of the fly like the tramp of an elephant — else the mere friction of the in- strument on the walls of the bladder would produce a noise quite capable of being confounded with that caused by the presence of calculus. The battery must not be too strong, else mere accidental friction of the wires or the noises of the room would produce a distinct sound in the telephone. But when care was taken there would be no difficulty in detecting the noise. An ordinary calculus was put in a bladder in a basin of water, and the listeners could distinctly hear the different noises produced by the point of the sound rasping against the walls of the blad- der or striking the stone. A sharp stroke of the former was sometimes not quite unlike the latter. But with the microphone properly adjusted, and the battery not too strong, it was not easy by trial to detect the presence of even a minute fragment of unremoved calculus in the bladder. The carbon needed only to be fitted to the probe, of course, to detect bullets or fragments of bone. But while it was quite possible for a skilful surgeon to make himself absolutely certain by means of the micro- phone of what he was previously only morally convinced of. Sir Henry Thompson did not appear to anticipate any very remarkable results, at least in ordinary practice, from the use of the instrument. NOTES We are happy to state that a Commission appointed by the French Chamber of Deputies has reported favourably on the erection of a large observatory at Meudon, on the site of the Chateau which has been in ruins since the Franco-German war. The credit given is 690,000 francs, which will be paid in two instalments, 345,000 in 1878, and 345,000 in 1879. A large part of that sum, 390,000 francs, is destined for the construction of a large refractor, 250,000 francs are for the buildings, and 50,000 francs for the salary of M. Janssen, his assistants, and petty expenses during two years. The credit will be voted very likely neviine obstante. We learn, with much satisfaction, that the Swedish Diet has granted the necessary funds to the Meteorological Observatory at Upsala, so well known for the high excellence of its work, and that it will commence its new course as a separate insti- tution, distinct from the Astronomical Observatory, on January I, 1879. On Thursday, May 30, Dr. Gladstone, F.R.S., P.C.S. gave a soiree to the Fellows of the Chemical Society at Burlington House. Amongst the numerous objects of interest were the following : — A magnificent collection of immediate principles from the brain exhibited by Dr. Thudichum, who also demon- 158 NATURE \yune6, 1878 strated the absorption spectrum of a new colouring matter, derived from eggshells, the bands being identical with those of cruentin, obtained from the blood. In the library were specimens of artificial corundum and emerald, made by Feil and Fremy ; a large Cape diamond, exhibited by Prof. Tennant ; a collection of precious stones from Hunt and Roskell, including a fine pink topaz, cat's eye, and a large crystal of garnet ; some interesting apparatus of Faraday, amongst which was his rheostat; a collection of alkaloids from opium, aconite, &c., by Dr. Wright ; a splendid case, by W. H. [Perkin, illus- trating the colouring matters from aniline, anthracene, &c. ; a specimen of artificial alizarin and preparations of natural and artificial salicylic acids, the latter of which the exhibitors, Messrs. Hopkin and Williams, have succeeded in obtaining in crystals exactly resembling those of the natural product. ^Minerals con- taining liquid carbonic acid were shown by W. N, Hartley, who also demonstrated the effect of heat on the liquid inclosed in the cavities : crystals from Owens College, including a large, almost perfect octohedron of chrome alum ; various interesting products, &c., were exhibited by Prof. Odling, Prof. Frankland, Dr. Russell, Dr. Armstrong, Dr. Witt, Dr. Schorlemmer, Dr. Hugo Miiller, and M. M. P. Muir. In the room adjoining the lecture-room were some candles which had been acted upon by sea- water for 173 years, a large collection of meteoric stones, an interesting series of photographs of invisible fluorescent bodie=, &c., exhi- bited by the President; a splendid photograph of the solar spectrum, shown by Mr. Rutherfurd ; the spectrum of bismuth was shown by Mr. Browning ; dichroic crystals of nickel and cobalt salts, by J. M. Thomson ; photographs illustrating his recent researches in solar chemistry, by J. N. Lcckyer ; an enormous cut cairngorm, weighing 51 oz. ; an opal cameo, and various minerals, by Bryce Wright, &c. In the lecture and preparation rooms were the microphone, exhibited by Prof. Hughes, which attracted considerable interest ; Mr. W. De la Rue showed some phosphorescent tubes which, after a momentary exposure to some burning magnesium, flashed back all the colours of the spectrum ; Byrne's pneumatic battery, and the copper zinc couple were shown in action ; Messrs. Murray and Heath exhi- bited, under the microscope, some pretty crystals of gold, silver, &c. ; Sir Joseph Whitworth and Dr. Siemens showed specimens of steel ; in the same room Dr. Guthrie exhibited the formation of cryohydrates. Many other objects of interest were exhibited^ but it would be impossible to enumerate all. The soiree was most successful, and althou gh the attendance was numerous, the arrangements were so good that at no time were the rooms inconveniently crowded. The publication of a work on the algK of North -America, to consist of the plants themselves properly put up and labelled, was commenced a year ago by the three eminent American algologists. Dr. W. G. Farlow, of Cambridge, Prof. D. C. Eaton, of Yale, and Dr. C. L. Anderson, of California. A second fasciculus has lately appeared, and maintains the ihigh character of the first. The death is announced of the venerable Baron von Ettings- hausen, in his eighty-second year. We hope to give some notice of his life next week. M. Mascart, the new director of the French Central Meteo- rological Bureau, took possession of the Bulletin International on June i, without making any alteration in the nature of its contents or its periodicity. On the preceding day he visited for the first time the meteorological division of the observatory, and warned the officials to prepare for being removed from the establishment at an early date, their rooms being wanted for enlarging the astronomical service. Thus the principle of separation will be carried into effect very shortly. We are glad, however, that M. Mascart stated that the services of M. Leverrier's assistants had been quite appreciated by the Govern- ment. None of them will lose their present situations, and an increase of their present salaries is contemplated. The head of the Warning Service for Agriculture and Marine is M. Fron, a former pupil of the Normal School, and the sub-director, M. Moureau, a former teacher in the Mutual Schools, whom M. Leverrier had distinguished for his activity and ingenuity. The present staff is composed of a few subordinates acting merely as computers, an autographist, and a telegraphist, W^E notice the death, on May 14, in Dresden, of Prof. Wilhelm Friedrich Georg Behn, an able anatomist and zoologist. He was borji in Kiel in 1S08, and, after the completion of his scientific studies, entered as private docent in the Kiel Uni- versity, where he received the chair of zoology in 1852. After the annexation of Schleswig-Holstein to Prussia he exchanged his professorship for one in Dresden. Here he was elected, in 1S69, to the presidency of the Leopoldina-Carolina Akademie der Naturforscher, a position which he occupied up to his death. The academy, although the oldest in Germany — being founded in 1652 — was then nearly on the point of dissolution. Prof. Behn's energetic efforts succeeded, however, in resuscitating it, and rendering it once more the centre of Saxon scientific life. At a general meeting of the Royal Irish Academy on Monday last week Cunningham gold medals were awarded to Dr. Aquila Smith for his inquiries into Irish numismatics ; Dr. Allman, F.R.S., for his researches into the natural history of the Hydrozoa ; and Dr. Casey for his important mathematical dis- coveries. The Dutch Society of Sciences^held its 126th general meeting on May 18. It \vas at this meeting that the Huygens Medal was awarded to Prof. Newcomb, who, along with Sir George Airy, Dr. Auwers of Berlin, Prof. Du Bois Reymond of Berlin, M. V, Duruy of Paris, and Dr. C. F. W. Ludwig of Leipzig, were elected foreign members. For a paper on the question "What are the meteorological and magnetic phenomena which there are sufficient reasons for believing are connected with solar spots," Prof. Fritz of Zurich Polytechnic, was awarded a prize of 150 florins. The proposer of the question. Dr. Buys Ballot, was awarded a silver medal. A number of subject for prizes were proposed for competition in 1879 and 1880, the most important of which we hope to give next week. In the June number of the American Journal of Science and Art Prof. Marsh announces one of the most interesting dis- coveries yet made in the Palteontology of the Rocky Mountains, which have lately produced so many novelties. This is the right lower jaw of a small opossum, of the family Didelphydse, for which he proposes the name Dryolestes priscus, from the Upper Jurassic series, in which no mammalian remains have previously been found in America. The first annual meeting of the Midland Union of Natural History Societies on May 27, at Birmingham, was, we are glad to say, a great success. After a luncheon given by the pre- sident, Mr. Tonks, a meeting was held at 3 p.m. in the Midland Institute, which was largely attended, as was also the brilliant conveisazione in the evening in the town-hall. An excursion to Dudley on Tuesday, attended by about 400 members and their friends, brought to a close a pleasant and profitable meeting. The annual meeting of the Sanitary Institute was held on Friday last. Dr. B. W. Richardson, president, in the chair. It was shown that the Institute had already done good work, and exercised a decided influence in relation to sanitary matters. T)\\ Richardson A>as reelected president. jfiine 6, 1878]^ NATURE 159 The Tay Bridge, at Dundee, was opened on Friday, in presence of a large and distinguished company. Two Reports come to us from Scotland — one on the Glasgow Industrial Museum, and the other on the Dundee Free Library. From the former we are glad to see that, under the energetic curator, Mr. James Paton, F.L.S., the Glasgow Museum is gradually becoming worthy of the second city of the kingdom. Many important additions are being made to the well-arranged museum, with which, we see, have been incorporated the Cor- poration Galleries of Art. We trust the successors of " Bailie Nicol Jarvie " and his contemporary councillors will exercise a wise liberality and speedily raise their museum to the position it ought to occupy. From the Report of Mr. Maclauchlan we are pleased to see that scientific works are in considerable demand among the busy people of enterprising Dundee. The interesting museum, also, is gradually becoming possessed of that complete collection of the Arctic fauna which strangers naturally look for in the museum of the chief seat of the whaling trade. In the Annalen der Hydrographie we notice the account of a group of three islands discovered by Capt. Caller in 1877 on the north-west coast of Australia. These islands, which in their highest point do not rise more than thirty feet above the level of the sea, are covered with a thick deposit of guano, con- taiuing an unusual amount of ammonia and phosphates. On account of their nearness to the continent these valuable de- posits will probably play an important part in the agricultural development of Australia. On October 4 last we gave an account of the post-mortem examination of a white whale {Beluga) that died after a few days' residence in a tank at the Westminster Aquarium. Mr. Farini then commissioned Zack Coup to obtain three more and bring them over from Labrador, They w^ere packed each in a separate box lined with sea-weed, and four men were engaged to relieve one another in throwing water over the heads of the animals during the entire voyage. On Tuesday, May 27, they arrived at Liverpool, when one specimen was sent to Blackpool, one to Manchester, and one was brought under the personal care of Mr. Farini and Mr. Carrington, the naturalist of the Aqua- rium, to Westminster. This London specimen is 13 ft. 6 in. long, and arrived in apparently good condition. On Friday it was found requisite to "sling" it in order to remove an eel that had be- come entangled in its right flipper, when its quick sight in trying to avoid the sling was noticed with interest. The legs of a man sitting on the edge of the tank it carefully avoided, but it did not seem to mind the presence of those standing round. After the whale had been in the tank four days an indication of malaise and apparently of some accident having occurred attracted the careful attention of those Mho had charge of it. It ivas then ascertained the specimen was a female, and was for a while a subject of interest to physiologists especially. A NEW improvement in the microscope is reported from Germany. Ilerr I. von Lenhossek has constructed an apparatus which permits no less than sixty microscopical preparations being observed in immediate succession, without the trouble of changing the slides and readjustment of the object-glass. Its construction is similar in principle to that of the weU-known revolving stereoscopes, and the inventor has given the new apparatus the name of " polymicroscoiie." Upon the occasion of miveiling the statue of Giordano Bruno, which will take place at Rome on February 19, 1879 a new edition of his works will be published. They are beino- reprinted at the expense of the Italian government. The Vienna Academy [of Sciences held its annual public ses.' ion on May 29, in the presence of representatives of the Court and Govei-nment. After the announcement of the various prizes and reports on the progress in the several sections of the Academy, Prof. Hann delivered an address on the " Problems of Modern Meteorolog>-." An Ethnographical Exhibition, organised by the Anthro- pological Society of Paris in an annexe to the Trocadero, was opened on May 31. M. Teisserenc de Borg, Minister for Com- merce and Agriculture was presen" on behalf of M. Bardoux, the Minister of Public Instruction, and declared the exhibition open. The addresses were delivered by MM. Quatrefages, Henri Martin, the president of the Society, and Dr. Broca. This exhibition is an extension of the Provisional Museum established for some months at the Palais de ITndustrie, in the Champs Elyse'es. We noticed at the time that M. Jules Simon, when French Minister for Public Instruction, had opened in the buildings of the Ministry, a provisional Pedagogical Museum, but a change having supervened in the Cabinet the scheme was dropped. It will, we learn now, be revived by M. Bardoux, who has asked special credit for that purpose from the Chamber of Deputies. The electric-light display in the Paris streets and thorough- fares ia becoming one of the attractions of Paris. Eight electric lamps have been placed in the Place de I'Opera, twenty-four others in the Opera Avenue, and eight more on the Place du Theatre Fran9ais. Six lamps were lighted for the first time on June i on the part of the Palais Bourbon facing the Place de la Concorde. We should notice also the private illumination of the Grands Magasins du Louvre, about seventy lamps ; Belle Jardiniere, eight ; Concert de I'Orangerie des Tuileries, twenty ; and the Hippodrome, thirty-two. This last illumination, being in a closed building, cannot be viewed from the streets. All these illuminations are made by the Jablochkow candles. An electric lamp has been placed also on the top of the Trocadero Palace. We notice that the list of jurors for the Paris Exhibition has been gazetted. The last number of thQ Journal of the Society of Arts con- tains a valuable paper, recently read by Mr. J. M. Thomson, F.C.S., befox-e the Society, on the Position of Chemistry in a System of Technical Education, as illustrated by some of its Applications. We are glad to see the Society turning its atten- tion to a subject of such great importance. The additions to the Zoological Society's Gardens during the past week include a Macaque Monkey {Macacus cynomolgus) from India, presented by Mr. J. Farmer ; a Geoffroy's Cat [Felis geoffroii) from Uruguay, presented by Mr. Ronald Bridgett ; a Brazilian Caracara {Polyborus brasUiensis) from South America, presented by Miss Amslie ; a Tamandua Ant- eater [Tamandua tetradactyla) from South America, deposited ; a White-eared Bulbul (Pycnonotus leucotis) from North-west India, received in exchange ; four Temminck's Tragopans {Ceriornis tejiiminckii), bred, a Yellow-footed Rock Kangaroo {Petrogale xanthopus), an Axis Deer {Cervus axis), born in the Gardens. THE REDE LECTURE 1 "XTIZHEN, about two years ago, news came from the other side of the Atlantic that a method had been invented of trans- mitting, by means of electricity, the articulate sounds of the human voice, so as to be heard hundreds of miles away from the speaker, those of us who had reason to believe that the report had some foundation in fact, began to exercise our imaginations in picturing some triumph of constructive skill — something as far surpassing Sir William Thomson's Siphon Recorder in deU- cacy and intricacy as that is beyond a common bell-pull. When I Given at Cambridge by Prof. Clerk-Maxwell, F.R.S., May 24, 1878 Subject — " The Telephone." i6o NATURE {June 6, 1878 at last this little instrument appeared, consisting, as it does, of parts, everyone of which is familiar to us, and capable of being put together by an amateur, the disappointment arising from its humble appearance was only partially relieved on finding that it was really able to talk. But perhaps the telephone, though simple in respect of its material and construction, may involve some recondite physical principle, the study of which might worthily occupy an hour's time of an academic audience : 1 can only say that I have not yet met anyone acquainted with the first elements of electricity who has experienced the slightest difficulty in understanding the physical process involved in the action of the telephone, I may even go further, and say that I have never seen a printed article on the subject, even in the columns of a newspaper, which showed a sufficient amount of misapprehension to make it worth preserving — a proof that among scientific subjects the telephone possesses a very exceptional degree of lucidity. However, if the telephone has something to say for itself, it would seem hardly necessary for me to take up your time with any tedious introduction. It is unfortunate, however, that up to the present time the telephone has kept all his more perfect utterances to be 'whispered into the privileged ear of a single listener. When he is older, he may get more accustomed to public speaking, but if we force him, in his present immature state, to exert his voice beyond what is good for him, it may sound rather too like the pot quarrelling with the kettle, and may call for the criticism with which Mr, Tennyson's Princess complimented the disguised Prince on his "Song of the Swallow : " — " Not for thee, she said, O Bulbul, any rose of Gulistan ShaU burst her veil : marsh divers rather, maid, Shall croak thee sister, or the meadow crake Grate her harsh kindred in the grass." Is it for this, then, that we are to forsake the luncheons and lawn tennis and all the engrossing studies of the May Term, and to assemble in this solemn hall, where the very air seems thick with the accumulation of unsolved problems, or else redolentof the graces of innumerable congregations ? It is not by concentrating our minds on any problem, however important, but rather by encouraging them to expand, that we shall best fulfil the intention of Sir Robert Rede when he founded this lecture. It would be as useless as it would be tedious to try to explain the various parts of this small instrument to persons in every part of the Senate House. I shall, therefore, consider the tele- phone as a material symbol of the widely sepr-rated departments of human knowledge, the cultivation of which has led, by as many converging paths, to the invention of this instrument by Professor Graham Bell. For whatever may be said about the importance of aiming at depth rather than width in our studies, and however strong the demand of the present age may be for specialists, there will always be work, not only for those who build up particular sciences and write monographs on them, but for those who open up such communications between the different groups of builders as will facilitate a healthy interaction between them. And in a university we are especially bound to recognise not only the unity of science itself, but the communion of the workers in science. We are too apt to suppose that we are congregated here merely to be within reach of certain appliances of study, such as museums and laboratories, libraries and lecturers, so that each of us may study what he prefers. I suppose that when the bees crowd round the flowers it is for the sake of the honey that they do so, never thinking that it is the dust which they are carrying from flower to flower which is to render possible a more splendid array of flowers, and a busier crowd of bees, in the years to come. We cannot, therefore, do better than improve the shining hour in helping forward the cross-fertilization of the sciences. Before we go further, I wish to express my obligation to Mr. Garnett for the able assistance he has given me. He has not only collected the apparatus before you, but constructed some of it himself. But for him, I might have given you some second- hand information about telephones. He has made it possible for you to hear something yourselves. I have also to thank Mr. Gower, who has brought his telephone harp, and Mr. Middleton, who has contributed several instruments of his own invention. We shall begin with the telephone in its most obvious aspect, as an instrument depending on certain physical principles. The apparatus consists of two instruments, the transmitter and the receiver, doubly connected by a circuit capable of conducting electricity. The speaker talks to the transmitter at one end of the line, and at the other end of the line the listener puts his ear to the receiver, and hears what the speaker says. The process in its two extreme stages is so exactly similar to the old-fashioned method of speaking and hearing that no pre- paratory practice is required on the part of either operator. We must not, however, fall into the error of confounding the principle of the electric telephone with that of other contri- vances for increasing the distance at which a conversation may be carried on. In all these the principle is the same as in the ordinary transmission of sound through the air. The different portions of matter which intervene between the speaker and the hearer take part, in succession, in a certain mechanical process. Each receives a certain motion from the portion behind it and communicates a precisely similar motion to the portion in front of it, in doing which it gives put all the energy it received, and is again reduced to rest. The medium which takes part in this process may be the open air, or air confined in a long tube, or some other medium such as a brick wall, as when we hear what goes on in the next house, or a long wooden rod, or a metal wire, or even a stretched string. In all these it is by the actual motion of the successive portions of the medium that the message is transmitted. In the electric telephone there is also a medium extending from the one instrument to the other. It is a copper wire, or rather two wires forming a closed circuit. But it is not by any motion of the copper that the message is transmitted. The copper remains at rest, but a variable electric current flows to and fro in the circuit. It is this which distinguishes the electric telephone from the ordinary speaking tube, and from the transmission of vibrations along wooden rods by which Sir Charles Wheatstone used to cause musical instruments to *und in a mysterious manner without any visible performer. On the other hand, we have to distinguish the principle of the articulating telephone from that of a great number of electrical contrivances which produce visible or audible signals at a dis- tance. Most of these depend on the alternate transmission and interruption of an electric current. In some part of the circuit a piece of apparatus is introduced corresponding to this instru- ment which is called a key. Whenever two pieces of metal, called the contact pieces, touch each other, the current flows from the one to the other, and so round the circuit. Whenever the contact pieces are separated the current is interrupted, and the effects of this alternation of current and no current may be made to produce signals at any other part of the circuit. In the Morse system of signalling, currents of longer and of shorter duration are called dashes and dots respectively, and by combinations of these the symbols of letters are formed. The rate at which these little currents succeed one another depends on the rate at which the operator can work the key, and may be increased by mechanical methods till the receiving clerk can no longer distinguish the symbols. But the capability of the telegraph wire for transmitting signals is by no means exhausted ; as the rapidity of the succes- sion is increased, the ear ceases to distinguish them as separate signals, but begins to recognise the impression it receives as that of a musical tone, the pitch of which depends on the number of currents in a second. Tuning forks driven by electricity were used by Helmholtz in his researches on the vowel sounds, and the periodically inter- mittent current which they furnish is recognised as a most valuable agent in physical and physiological research. The tuning forks are of the most massive construction, and the succession of currents goes on with the most inflexible regularity, so that when- ever we have occasion to follow the march of a process which takes place in a short time, such as the vibration of a violin string or the twitch of a living muscle, the tuning fork becomes our appropriate timepiece. Apparatus of this kind, however, the merit of which is its re- gularity, is quite incapable of adapting itself to the transmission of variable tones such as those of a melody. The first successful attempt to transmit variable tones by electricity was made by Philip Reis, a teacher in a school at Friedrichsdorf, nearHomburg. On October 21, 1861, Reis showed his instrument, which he called a telephone, to the Physical Society of Frankfort on the Main, He succeeded in trans- mitting melodies which were distinctly heard throughout the room. The transmitter of Reis's telephone is essentially a make and yune(i, 1878] NATURE 161 break key of so delicate a constniction that the sound-waves in the air are able to work it. The air vibrations set in motion a stretched membrane like a drumhead, with a piece of platinum fastened to it. This piece of platimrm, when vibrating, strikes against another piece of platinum, and so completes the circuit every time contact is made. At every point of the circuit there is thus a series of currents corresponding in number to the vibrations of the drumhead, and by causing these to pass through the coil of an electromagnet, the armature of the electromagnet is attracted every time the current passes, and if the annature is attached to a resonator of any kind, the succession of tugs will set it in vibration, and cause it to emit a sound, the pitch of which is the same as that of the note sung into the transmitter at the other end of the line, [Mr. Gower here played the " March of the Men of Harlech " on the telephone harp placed in the Geological Museum. The instrument consists of a set of steel reeds worked by percussion, which make and break contact on the battery circuit, of which the primary wire of an induction coil forms part. The receivers are worked by the secondary current There were four receivers, one of them Prof. Bell's original one, placed in different parts of the Senate-house.] If the pitch of a sound were the only quality which we are able to distinguish, the problem of telephony would have received its complete solution in the instrument of Reis. But the human ear is so constructed, and we ourselves are so trained by con- tinual practice, that we recognise distinctions in sound of a far more subtle character than that of pitch ; and these finer dis- tinctions have become so much more important for the purposes of human intercourse than the musical distinction of pitch, that many persons can detect the slightest variation in the pronuncia- tion of a word who are comparatively indifferent to the variations of a melody. Now, the telephone of I'rof. Graham Bell is an articulating telephone, which can transmit not only melodies sung to it, but ordinary speech, and that so faithfully that we can often recog- nise the speaker by his voice as heard through the telephone. How is this effected ? It is manifest that if by any means we can cause the tinned plate of the receiving instrument to vibrate in precisely the same manner as that of the transmitter, the impres- sion on the ear will be exactly the same as if it had been placed at the back of the plate of the transmitter, and the words will be heard as if spoken at the other side of a tinned plate. But this implies an exact correspondence, not only in the number of vibrations, but in the type of each vibration. Now, if the electrical part of the process consisted merely of alternations between current and no current, the receiving instru- ment could never elicit from it the semblance of articulate speech. If the alternations were sufficiently regular, they would produce a sound of a recognisable pitch, which would be very rough music if the pitch were low, but might be less unendurable if the pitch were high ; still, at the best, it would be like playing a violin with a saw instead of a bow. What we want is not a sudden starting and stopping of the current, but a continuous rise and fall of the current, correspond- ing in every gradation and inflexion to the motion of the air agitated ly the voice of the speaker. Prof, Graham Bell has recounted the many unsuccessful attempts which he made to produce undulatory currents instead of mere intermittent ones. He had, of course, to give up alto- gether the method of making and breaking contact. Every method involving impact of any kind, whether between electric contact pieces or between the sounding parts of the instalment, introduces discontinuity of motion, and therefore precludes a faithful reproduction of speech. In the ultimate form which the telephone in his hands assumed, the electric current is not merely regulated but actually generated by the aerial vibrations themselves. The electric principle involved in Bell's telephone is that of the induction of electric currents discovered by Faraday in 1831. Faraday's ow n statement of this principle has been before the scientific world for nearly half a century, but has never been im- proved upon. Consider first a conducting circuit, that is to say, a wire which after any number of convolutions returns into itself. Round such a circuit an electric current may flow, and will flow if there is an electromotive force to drive it. Consider next a line of magnetic force, such a line as you see here made visible by sprinkling iron filings on a sheet of parafiin paper. This line, as Faraday also first showed, is a line return- ing into itself, or, as the mathematicians would say, it is a closed ciurve. Now, if there are two closed curves in space, they must either embrace one another so as to be linked together, or they must not embrace each other. If the line of force as well as the circuit were made of wire, and if it embraced the copper circuit, it would be impossible to unlink them without cutting one or other of the wires. But the line of force is more like one of Milton's spirits, which cannot " In their liquid texture mortal wound Receive, no more than can the fluid air." Now, if the copper circuit or the lines of force move relatively to each other, then in general some of the lines of force which originally embraced the circuit will cease to embrace it, or else some of those which did not embrace it will become linked with it. For every line of force which ceases to embrace the circuit there is a certain amount of positive electromotive force, which, if unopposed, will generate a current in the positive direction, and for every new line which embraces the circuit there is a negative electromotive force, causing a negative current. In Bell's telephone the circuit forms a coil round a small core of soft iron fastened to the end of a steel magnet. Now lines of magnetic force pass more freely through iron than through any other substance. They will go out of their way in order to pass through iron instead of air. Hence a large proportion of the lines of force belonging to the magnet pass through the iron core, and, therefore, through the coil, even though there is no iron beyond the core, so that they have to complete their circuit through air. But if another piece of soft iron is placed near the end of the core it will afford greater facilities for lines which have passed through the core to complete their circuit, and so the lines belonging to the magnet will crowd still closer together to take advantage of an easy passage through the core and the iron beyond it. If then the iron is moved nearer to the core, there will be an increase in the number of such lines, and, therefore, a negative current in the circuit. If it is moved away there will be a diminution in the number of lines, and a positive current in the circuit. This principle was employed by Page in the construc- tion of one of the earliest magneto -electric machines, but it was reserved for Prof. Bell to discover that the vibrations of a tinned iron plate, set in motion by the voice, would produce such currents in the circuit as to set in motion a similar tinned plate at the other end of the line. It will help us to appreciate the fertility of that germ of science which Faraday.first detected and developed if we recollect thatyear after year he had employed the powerful batteries and magnets and delicate galvanometers of the Royal Institution to obtain evidence of what he all along hoped to discover — the production of a current in one circuit by a current in another, but all without success, till at last he detected the induced current as a transient pheno- menon, to be observed only at the instant of making or breaking the primary circuit. In less than half a centtuy, and by the aid of no second Fara- day, but in the course of the ordinary growth of scientific princi- ple?, this germ, so barely caught by Faraday, has developed on the one hand into the powerful ciurents which maintain the illu- mination of the lighthouses on our coasts ; and on the other, into these currents of the telephone which produce an audible effect, though the engine that drives them is itself driven by the tremors of a child's voice. Prof, Tait has recently measured the absolute strength of these telephone currents. He produced them by means of a tuning fork vibrating in front of the coil of the transmitter. Before the transmitted note ceased to be audible at the other end of the line he measured by means of a microscope the ampli- tude of the vibrations of the fork. He then placed a very delicate galvanometer in the circuit and found what deflexion was produced by a measiu-ed motion of the fork. Finally he measured the deflection of the galvanometer pro- duced by a small electromotive force of known magnitude. He thus found that the telephone currents produced an audible effect when reversed 500 times a second, though their strength was no greater than what a Grove's cell would send through a million megohms, about a thousand million times less than the currents used in ordinary telegraphic work. ; l62 NATURE [y uric 6, 1878 One great beauty of Prof, Bell's invention is that the instru- ments at the two ends of the line are precisely alike. When the tin plate of the transmitter approaches the core of its bobbin it produces a current in the circuit, which has also to circulate round the bobbin of the receiver, and thus the core of the receiver is rendered more or less magnetic, and attracts its tin plate with greater or smaller force. Thus the tin plate of the receiver reproduces on a smaller scale, but with perfect fidelity, every motion of the tin plate of the transmitter. This perfect symmetry of the whole apparatus — the wire in the middle, the two telephones at the end of the wire, and the two gossips at the ends of the telephones — may be very fasci- nating to a mere mathematician, but it would not satisfy an evolutionist of the Spencerian type, who would consider any- thing with both ends alike to be an organism of a very low type, which must have its functions differentiated before any satisfactory integration can take place. Accordingly, many attempts have been made, by differentiating the function of the transmitter from that of the receiver, to over- come the principal limitation to the power of the telephone. As long as the human voice is the sole motive power of the appara- tus it is manifest that what is heard at one end must be fainter than what is spoken at the other. But if the vibration set up by the voice is used no longer as the source of energy, but merely as a means of modulating the strength of a current produced by a voltaic battery, then there will be no necessary limitation of the intensity of the resulting sound, so that what is whispered to the transmitter may be proclaimed ore rotundo by the receiver, A result of this kind has already been obtained by Mr. Edison by means of a transmitter in which the sound vibrations produce a varying pressure on a piece of carbon, which forms part of the electric circuit. The greater the pressure, the smaller is the resistance due to the insertion of the carbon, and therefore the greater is the current in the circuit. I have not yet seen Mr. Edison's transmittei*, but the micro- phone of Prof. Hughes is an application of carbon and other substances to the construction of a transmitter, which modulates the intensity of a battery current in more or less complete ac- cordance with the sound-vibrations it receives. The energy of the sound produced is no longer limited by that of the original sound. All that the original sound does is to draw supplies of energy from the battery, so that a very feeble sound may give rise to a considerable effect. Thus, when a fly walks over the table of the microphone the sound of his tramp may be heard miles off. Indeed, the microphone seems to open up several new lines of research. We shall have London physicians performing stetho- scopic auscultations on patients in all parts of the kingdom. The Entomological Society have recently been much interested by Mr. Wood-Mason's discovery of a stridulating apparatus in scorpions. Perhaps ere long a microphone, placed in a nest of tropical scorpions, may be connected up to a receiver in the apartments of the society, so as to give the members and their musical friends an opportunity of deciding whether the musical taste of the scorpion resembles that of the nightingale or that of the cat, I have said that the telephone is an instance of the benefit to be derived from the cross-fertilization of the sciences. Now this is an operation which cannot be performed by merely collecting treatises on the different sciences, and binding them up into an encyclopsedia. Science exists only in the mind, and the union of the sciences can take place only in a living person. Now, Prof. Graham Bell, the inventor of the telephone, is not an electrician who has found out how to make a tin plate speak, but a speaker, who, to gain his private ends, has become an electrician. He is the son of a very remarkable man, Alexander Melville Bell, author of a book called "Visible Speech," and of other works relating to pronunciation. In fact, his whole life has been employed in teaching people to speak. He brought the art to such perfection that, though a Scotchman, he taught himself in six months to speak English, and I regret ex- tremely that when I had the opportunity in Edinburgh I did not take lessons from him. Mr. Melville Bell has made a complete analysis and classification of all the sounds capable of being uttered by the human voice, from the Zulu clicks to coughing and sneezing ; and he has embodied his results in a system of symbols, the elements of which are not taken from any existing alphabet, but are founded on the different configurations of the organs of speech. The capacities of this new mode of representing speech have been put to the test by Mr. Alexander J. Ellis, author of "The Essentials of Phonetics," a gentleman who has studied the whole theory of speech acoustically, philologically, and historically. He describes the result in a letter to The Reader : — " The mode of procedure was as follows :— Mr, Bell sent his two sons, wli ") were to read the writing, out of the room — it is interesting to know that the elder, who read all the words in this case, had only had five weeks' instruction in the use of the alphabet — and I dictated slowly and distinctly the sounds which I wished to be written. They consisted of a few words in Latin, pronounced first as at Eton, then as in Italy, and then according to some theoretical notions of how the Latins might have uttered them. Then came some English provincialisms and affected pronunciations, the words 'how odd' being given in several distinct ways. Suddenly German provincialisms were introduced; then discriminations of sounds often confused. Some Arabic, some Cockney English, with an introduced Arabic guttural, some mispronounced Spanish, and a variety of shades of vowels and diphthongs. " The result was perfectly satisfactory — that is, Mr. Bell wrote down my queer and purposely exaggerated pronunciations and mispronunciations, and delicate distinctions, in such a manner that his sons, not having heard them, so uttered them as to sur- prise me by the extremely correct echo of my own voice. . , . Accent, tone, drawl, brevity, indistinctness were all reproduced with surprising accuracy. Being on the watch, I could, as it were, trace the alphabet in the lips of the readers. I think, then, that Mr. Bell is justified in the somewhat bold title which he has assumed for his mode of writing — ' Visible speech.' I only hope that for the advantage of linguists, such an alphabet may soon be made accessible, and that, for the intercourse of nations, it may be adopted generally, at least for extra- European nations, as for the Chinese dialect and the several extremely diverse Indian languages, where such an alphabet would rapidly become a great social and political engine." The inventor of the telephone was thus prepared, by early training in the practical analysis of the elements of speech, to associate whatever scientific knowledge he might afterwards ac- quire with those elementary sensations and actions, which each of us must learn from himself, because they lie too deep within us to be described to others. This training was put to a very severe test when, at the request of the Boston Board of Educa- tion, Prof. Graham Bell conducted a series of experiments with his father's system in the Boston School for the Deaf and Dumb. I cannot conceive a nobler application of the scientific analysis of speech, than that by which it enables those to whom all sound is "expunged and rased And wisdom at one entrance quite shut out " not only to speak themselves, but to read by sight what other people are saying. The successful result of the experiments at Boston is not only the most valuable testimonial to the father's system of visible speech, but an honour which the inventor of the telephone may well consider as the highest he has at-' tained. An independent method of research into the process of speech was employed by Wheatstone, Willis, and Kempelen, the aim of which was to imitate the sounds of the human voice by means of artificial apparatus. This apparatus was in some cases modelled so as to represent as nearly as possible the form as well as the functions of the organs of speech, but it was found that an equally good imitation of the vocal sounds could be ob- tained from apparatus the form of which had no resemblance to the natural organs. Several isolated facts of considerable importance were esta- bUshed by this method, but the whole theory of speaking and. hearing has been so profoundly modified by Helmholtz and Donders, that much of what was advanced before their time has come to possess only an historical interest. Among all the recent steps in the progress of science, I kno\r none of which the truly scientific or science-producing conse- quences are likely to be so influential as the rise of a school oi physiologists, who investigate the conditions of our sensations by producing on the external senses impressions, the physical condi- tions of which can be measured with precision, and then record- ing the verdict of consciousness as to the similarity or difference of the resulting sensations. Prof. Helmholtz, in his recent address as Rector of the Uni- versity of Berlin, lays great stress on that personal interaction, between living minds, which I have already spoken of as essen- yune6, 1878] NATURE 163 tial to the life of a University. "I appreciate," he say 5, "at its full value this last advantage, when, looking back, I recall my student days, and the impression made upon us by a man like Johannes Miiller, the physiologist. When one finds himself in contact with a man of the first order, the entire scale of one's intellectual conceptions is modified for life ; contact with such a man is perhaps the most interesting thing life may have to offer." Now, the form in which Johannes Miiller stated what we may regard as the germ which fertilized the physiology of the senses is this, that the difference in the sensations due to different senses does not depend upon the actions which excite them, but upon the various nervous arrangements which receive them. To accept this statement out of a book, as a matter of dead faith, may not be difficult to an easy-going student ; but when caught like a contagion, as Helmholtz caught it, from the lips of the living teacher, it has become the guiding principle of a life of research. No man has done more than Helmholtz to open up paths of communication between isolated departments of human know- ledge ; and one of these, lying in a more attractive region than that of elementary psychology, might be explored under excep- tionally favourable conditions, by some of the fresh minds now coming up to Cambridge. Helmholtz, by a series of daring strides, has effected a passage for himself over that untrodden wild between acoustics and music — that Serbonian bog where whole armies of scientific musicians and musical men of science have sunk without filling it up. We may not be able even yet' to plant our feet in his tracks and follow him right across. That would require the seven league boots of the German colossus ; but to help us in Cam- bridge we have the Board of Musical Studies, vindicating for music its ancient place in a liberal education. On the physical side we have Lord Rayleigh laying the foundation deep and strong in his " Theory of Sound." On the aesthetic side we have the University Musical Society doing the practical work, and in the space between, those conferences of Mr. Sedley Taylor, where the wail of the siren draws musician and mathe- matician together down into the depths of their sensational being, and where the gorgeous hues of the phoneidoscope are seen to seethe and twine and coil like the " Dragon boughs and elvish emblemlngs " on the gates of that city where " an ye heard a music, like enow They are building still, seeing the city is built To music, therefore never built at all, And therefore built for ever. " The special educational value of this combined study of music and acoustics is that more than almost any other study it in- volves a continual appeal to what we must observe for ourselves. The facts are things which must be felt ; they cannot be learned from any description of them. All this has been said more than two hundred years ago by one of oiu: own prophets — William Harvey, of Gonville and Caius College. ** For whosoever they be that read authors, and do not by the aid of their own senses, abstract true representations of the things themselves (comprehended in the author's expres- sions) they do not resent tme ideas, but deceitful idols and phan- tasms, by which they fi-ame to themselves certain shadows and chimaeras, and all their theory and contemplation (which they call science) represents nothing but waking men's dreams and sick men's phrensies." Prof. Maxwell was assisted in his practical demonstrations by Mr. Gamett, of St. John's College. SOCIETIES AND ACADEMIES London Physical Society, April 13.— Prof. R. B. Clifton, vice- president, in the chair. — The following candidates were elected Members of the Society :— W. Campbell, R. W. F. Harrison, Rev. T. N. Hutchinson, M.A., B. W. Richardson, M.B., F.R.S. — The Secretary read a paper by Messrs. J. Nixon and A. W. Heaviside, describing their experiments on the mechani- cal transmission of speech through wires or other substances, to which Mr. Preece had referred at a previous meeting of the Society. After describing a number of experiments in which metallic discs soldered on to the ends of the conducting wires were employed, they went on to enumerate the more success- ful experiments in which wooden discs were mainly employed. The first actual transmission of speech was effected by placing the belly of a violin against the receiving end of the wire, when every syllable spoken was distinctly audible. Very good results were obtained by employing mouth-and-ear pieces, formed as in a telephone, the disc being replaced by thin wooden discs, six inches in diameter, and a No. 4 wire was found to be most satisfactory. On suspending a length of this wire in such a manner that it had no rigid attachments, it was ascertained that 120 yards is the limit through which a conversation can be carried on. — Capt. Abney, F.R.S. , described the method he adopted for photographing the least refrangible end of the spectrum. He pointed out that it is impossible, with the ordi- nary sensitive salts employed in the usual way, to photograph further than the Fraunhofer line E, though by a preliminary exposure to light of a Daguerrotype plate, Draper was able to photograph beyond the extreme limit of visibility in the red end of the spectrum. This method, however gave what is known as a reversed picture, the lights and shades being transposed, besides requiring a lengthened exposiure. It enabled Becquerel to photograph the spectrum in its natural colours, and later St. Victor obtained coloiured images of colom-ed cloths. The object of Capt. Abney had been to obtain unreversed pictures of this portion of the spectrum ; in other words, to obtain a compound that would be similarly sensitive to the red and the blue components of white light. Such a compound he had at last obtained by what he termed weighting silver bromide with resin, and now he obtains it by causing the molecules of sUver bromide to weight themselves. He showed an ordinary bromide of silver plate, and the colour of the transmitted light was of a ruddy tint, showing absorp- tion of the blue rays ; another film was shown containing weighted bromide of silver, which transmitted blue light and absorbed the red. Photographic plates prepared with the latter compound he showed were sensitive to the red and ultra-red waves of light, and he threw on the screen photographs of the spectrum from the line C to a wave-length of 10,000, the ultra- red showing remarkable groupings of lines. He fiu-ther showed that by friction the blue film was changed to the red, and in that state was not sensitive to the lower part of the spectrum. These photographs were taken by means of a diffraction grating, and Capt. Abney demonstrated Fraunhofer 's method of separating the various orders of spectra produced by it. He then explained that recently he had elucidated the reason of the reversal of Draper's pictures by the least refrangi'ole end of the spectrum. He finds that it is accelerated by exposing the plates in weak oxidising solutions, such as those of hydroxyl, bichromate of potash, permanganate of potash, and nitric acid, or exposure to ozone. The red rays, in other words, seemed to oxidise the photographic image, and to render it incapable of development. — Mr. H. Bauermathen exhibited some paper models illustrative of the disposition of the planes of symmetry in crystals. These included octants of the sphere with inclosed cube and octahedron faces pointed into their corresponding hexakis-octohedral faces, a cubic skeleton built up from nine planes of symmetry with a removable outer shell, and a system of axial planes of an unsymmetrical mineral inclosing a solid nucleus contained between three parallel pairs of planes. They were constructed for the purpose of showing popularly the difference between planes of symmetry and other diametral planes by laying upon them a small mirror or plate of mica, when in the first case the inclosed nucleus gave a symmetrical image corresponding in position to the plane immediately behind the mirror, but in the second a broken image is produced. — Dr. Guthrie exhibited the arrangement of apparatus he had em- ployed, in conjunction with his brother, to ascertain the effect of heat on the transpiration of gases. The main difficulty connected with the research was the securing of an absolutely constant l^ressure on the air operated upon. This was secured by inserting into the neck of the vessel which served as an air-chamber a tube turned up at its inner end and terminating externally by a small funnel ; as the tube was kept constantly full of water, the funnel overfloAving, a pressure represented by the difference between the heights of these levels was maintained. After passing through a series of drying tubes the air traversed the (U-shaped) capillary tube in a beaker containing water of known temperature, and was finally received in an inverted tube contained in an overflow- ing dish of water. Among other results it was found that the resistance of a tube is the same as that of its several portions. 1 64 NATURE [June 6, 1878 and if t be the time occupied, T the absolute temperature, p^ p^ the pressures, and a and y3 constants, they find that— t=aT(T + ^V Chemical Society, May 16. — Dr. Gladstone, president, in the chair. — The following papers were read : — On the detection and estimation of free mineral acids in various commercial pro- ducts, by Peter Spence and A. Esilmann. The method is based on the fact that peracetate of iron even in dilute solutions has a distinct yellow colour, not perceptibly altered by acetic acid or solutions of persulphates, but instantly bleached by free sulphuric, hydrochloric, and nitric acids. The solution is made by dissolving ten parts of iron alum and eight parts of crystallised acetate of soda in 1,000 parts of 8 per cent, solution of acetic acid (25 per cent.). — The action of hypochlorites on urea, by H. G. H. Fenton. The author has found that when urea is acted on by a hypochlorite in the cold, in the presence of a caustic alkali, only half the nitrogen is evolved. From various experiments it was proved that the nitrogen remains behind as a cyanate. — On the behaviour of metallic solutions with filter paper and on the detection of cadmium, by T. Bayley. The author has investi- gated the action which takes place when drops of metallic solu- tions are placed on filter paper, the extent to which the splutions spread being tested by sulphuretted hydrogen. In some cases the solution seemed to concentrate itself in the middle, in others round the edge of the spot. Dilution, temperature, and the kind of filter paper used, have an important influence on this phenomenon. The salts of silver, lead, &c., when moderately concentrated, give a wide water ring containing no metal, while the salts of copper, nickel, cobalt, and especially cadmium, must be much more dilute to present the same appearance. This property of cadmium to spread itself over the whole drop is so marked that it affords an elegant means of detecting it in the presence of metals whose sulphides are black. — On essential oil of sage, by S. Siguira and M. M. P. Muir. The oil consists mainly of two terpenes, one boiling at 152-156° the toher 162-167°, an oxidised liquid and a camphor. — A small quantity of absolutely pure sage oil has been examined, and consists mainly of a terpene boiling at 264-270°, of a dark emerald green colour. — On the action of bromine upon sulphur, by J. B. Hannay. The author has investigated the evidence as to the existence of any compounds of these two elements by boiling points, the spectrum of the vapour, specific gravity, and vapour tension. He concludes that the action of any quantity of bromine or any quantity of sulphur is an action on the whole mass and not in multiple proportion, but that if at low temperatures the compound containing one atom of sulphiu: to two of bromine meets a body with which it can form a mole- cular combination, eg., arsenic, it assumes the crystalline form in conjunction with such a body.— On the determination of high boiling-points, by T. Carnelly and W. C. Williams. The authors have determined the boiling-points of various substances by observing whether or not certain salts fuse when exposed to the vapour of the boiling substance. The melting-points of the salts have been determined by Carnelly. The salts are contained in capillary tubes. — On high melting-points. Part IV., by T. Carnelly, D.Sc. The author has perfected his (specific heat) method of determining melting-points, and eliminated two sources of error. In the present paper he gives the melting- points of over one hundred substances. He promises a paper em- bodying theoretical results deduced from the above observations. Paris Academy of Sciences, May 27. — M. Fizeau in the chair. — The following among other papers were read : — On the produc- tion and constitution of chromised steels, by M. Boussingault. This memoir gives experiments proving that chromium, without the presence of iron, does not communicate to pure iron the properties of steel ; analyses of cast chromium steel ; experi- ments on the temper, and resistance to shock and traction, of chromised steel ; mode of preparation of it and ferrochrome, &c. — On the action of anaesthetics on the respiratory centre and cardiac ganglions, by M. Vulpian. In chloralised dogs faradisa- tion of the upper cephalic segments of the cut vagi stops the respiratory movements just as in dogs not ansssthetised ; but whereas, in the latter, the respiration in general easily and spon- taneously commences again, spite of the electrisation being con- tinued, it is not so with the former, and the animals die unless electrisation be stopped and artificial respiration be produced, aided, it may be, by energetic faradisation of the trunk. The heart, too, may finally stop in such a case. M. Vulpian thinks this explains certain accidents in clinic ancesthesia. — On the origin of the excito-sudoral nerve-fibres in the sciatic nerve of the cat by M. Vulpian. Those in the abdominal cord of the great sym- pathetic come from the spinal cord, chiefly by the first and second lumbar nerves; but there are others, and more, which come directly from the spinal cord by the roots of the sciatic nerve. An analogy with the nerves of the salivary glands is indicated. — M. de Lesseps gave details of the pacific conquests, made in the name of the Khedive of Egypt, by Gen. Gordon, and quoted from an official Egyptian report on Capt. Burton's recent im- portant discoveries in Arabia. — Transparent hydrated silica and hydrophane opal, obtained by action of oxalic acid on alkaline silicates, by M. Monier. The experiment should be made with 500 to 600 grammes of silicate of 35° or 40° B ; the oxalic acid is diluted to only four degrees. Letting the acid act six months at ordinary temperature, a transparent silicious layer was ob- tained, which, after heating to expel hygrometric water, took the milky colour and the hardness of opal. It becomes trans- lucid again in water. — On the cost of establishment of lightning- conductors, by M. Melsens. He proves that his system of numerous free conductors and multiple earth-connections is generally less expensive than the construction of the ordinary lightning-conductors. — On a disorder, not hitherto described, of wines of the south of France called vins tournh, by M. Gautier. This appears after warm and rainy autumns. The wine becomes troubled, its surface irisated ; the colouring matter passes from red to violet-blue, and is precipitated, the supernatant liquor being yellowish-brown, and having a baked odour and an acidulated and slightly bitter taste. These changes are worked by a parasite which appears in filamentous form in the deposit. — On the production of the luminous sensation, by M. Charpentier. Where we find less red substance in the retina, we observe a less luminous sensibility, and wherever the red appears in excess this sensibility is exaggerated. It is concluded that the luminous sensibility, defined as the simple and original reaction of the visual apparatus to all luminous excitations of w'hatever nature, is in relation to the degree of photo-chemical action exercised on the red of the retina by all the luminous rays.— On the physiological properties of conine, by MM. Bochefontaine and Tiriakian. Conine pure, or bromhydrate of conine, is not a very formidable poison, and not to be compared with hydro- cyanic acid (as has been supposed). 65 centigr. of pure conine introduced under the skin of a dog weighing 7 kil. odd killed it in a little over twelve hours ; 50 centigr. sufficed for a similar dog when introduced into the stomach. The chlorhydrate and bromhydrate are always more active than the pure conine. M. Mourrut has separated from the conine furnished as pure in shops a resinoid matter, which, like curare, paralyses the motor nerves. — Rdle of auxiliary acids in etherification ; thermal experiments, by M. Berthelot.— On some peculiarities presented in the arrangement of fire-damp in pits and old works, by M. Coquillion. CONTENTS pITe Modern Naval Architecture. By E. J. Reed, C.B., M.P., F.R.S „• 137 Tropical Nature. By Prof. E. Perceval Wright 140 Letters TO THE Editor: — ^ . t . Extinct and Recent Irish Mammals.— Prof. A. Leith Adams. . 141 Hints to Workers with the Microscope.— F. A. Bedwell . . . .141 The Virial in Thermodynamics.— Prof. A. S. Herschel .... 142 The Meteor of May 12.— J. Edmund Clark 142 "Divideetlmpera."—E. W.White, F.Z.S., S.S.Z. A 142 A Quadruple Rainbow.— Henry P. Dowling 142 Classes for Women at University College.— Talfourd Ely ... 143 Prof. Joseph Henry, LL.D ^43 Major-General Sir Andrew Scott Waugh 14S The Harvey Tercentenary i45 Our Astrono.mical Column : — The Transit of Mercury '47 The Zodiacal Light and Sun-spot Frequency ••■•'„•• ^'•'^ The International Geological Congress. By Prof. 1. S terry Hunt, Secretary of the International Committee 140 A Kinematical Theorem. By A. B. Kempe 140 Old Maps of Africa (With Mafis) •■■■•• u • A ■•' ^^"^ Cosmic Meteorology, II. By John Allan Broun, l<.K.b.. . . 151 The Nutrition of Drosera Rotundifolia. By Francis Uarwin 153 Physical Science for Artists, V. By J. Norman Lockybr, F.R.S. (With Illustrations) '54 The Microphone in Surgery ^57 The ReijeLecture. ' By Prof. Clerk-Maxwell, F.R.S i59 Societies and Academies • -^^ Errata. -In Prof. Lankester's review of Balfour's " Elasmobranch Fishes " vol. xviii. p. 114, 2nd column, line 22 from top, for /^.;«^^^«^^/« read homogenetij \^ Dr. Siemens' letter on the microphone p 129 1 1st columnf lines 25 and 28 from top, for '.corpuscular bodies read cor-^ pnscular matter. NA TURE 165 THURSDAY, JUNE 13, i^ ETHNOLOGY OF NORTH-WEST AMERICA United States Geographical and Geological Survey of the Rocky Mountain Region; Tribes of the Extreme North- West. By W. H. Dall. Tiibes of Western Washington and North-Western Oregon. By Geo. Gibbs. (Washington, 1877.) WE have already had occasion to draw attention to the extremely good work which is being done by the United States Geographical and Geological Survey, as well as to the liberal construction put upon the duties attached to it. The yolume now issued is another striking illustration of both facts, and makes us wish that other Governments would follow the example of that of America. For the first time we have full and accurate details regarding the Eskimaux and other tribes of what was once Russian America and of the adjoining territory. Not only has all the available literature on the subject been consulted, but the errors and deficiencies of former writers have been corrected and supplemented by personal and patient observation. A wholly new light has been cast on the ethnology of these remote regions, and both the ethnologist and the philologist will obtain fresh ma- terials of the utmost value. The scanty and often inac- curate information we have hitherto possessed has now been replaced by the full and careful statements of scientifically trained observers. Mr. J. W. Powell was the geologist in charge of the expedition, and it is the materials collected by him and his assistants that have been thrown into shape and edited in the present volume by Mr. W. H. Dall and the late Mr. George Gibbs. Mr. Dall's elaborate articles on the tribes of the extreme North-West acquire additional importance from the fact that they represent in large measure the fruits of his own researches. Since 1865 he has visited nearly the whole of the north-west coast, be- sides a good deal of the interior, and his statements have consequently all the advantage of being the results of personal knowledge. His first article describes the various tribes of Alaska and the adjacent territory, com- prising the Innuit or Eskimaux, and their off-branch, the Aleuts, and the Indian tribes belonging to the Tinneh and T'linket groups. Mr. Dall seems to exclude the Chukchis from the Innuit family ; to use his own words, they are "totally distinct in language and race from the nomadic 'reindeer-people' with whom they trade." Their trade-jargon, by the way, is a lingua franca com- posed of words or corruptions of words belonging to both. However, nothing is more remarkable than the differ- ences in manners and condition between many of the tribes described by Mr. Dall, who must, nevertheless, be of the same origin, and this fact shows how rapidly and widely savage tribes will come to differ from one another, even when living in close proximity. Mr. Dall's second article is a very interesting one on his exploration of the numerous kitchen -middens of the Aleutian Islands. Usually the middens consist of three layers, the lower most being composed of echinus and similar shells, the second of fishbones, and the third of mammalian and other remains, the ruins of villages of a more recent period often crowning the whole deposit. The lower- VoL. XVIII. — No, 450 most layer must go back to a remote date, and as Mr. Dall points out, would have required an immense number of years to form. The savages to whom it bears witness? must have been very low in the scale of humanity. They have left no traces of fire, weapons, or implements ; indeed, had they possessed any, they would hardly have been content to subsist on sea-eggs. It is only towards the top of the layer that net-sinkers of a very rude pattern have been met with ; but these may have worked their way through from the layer above, though the possibility does not seem to have suggested itself to Mr. Dall. With the fish-bone layer stone tools come into use ; as Mr. Dall observes, "fish, Avhen raw, is a substance which cannot be conveniently dismembered by teeth and nails." But it is not till we come to the mammalian epoch that the weapons show a decided improvement in form with attempts at ornamentation, though from the first the types are remarkably like those still used by the Eskimaux. Lamps, also, first came into use during this period, and no doubt the improvement in the tools was largely due to the lengthening of the working day by the introduction of artificial light. Mr. Dall's third article is on the Origin of the Innuit. He differs from Mr. C. R. Markham in thinking that the Innuit emigration goes back to a vast antiquity, and agrees with Dr. Rink in holding that the Innuit have not come from northern Asia, but been pushed northward from the interior of America itself. Like the walrus they can be shown to have once ranged as far south as New Jersey. He admits, however, that green patches similar to those that mark the Aleutian kitchen-middens, have been observed by whalers on the shores of Wrangell Land, and he is certainly wrong in stating that " Lin- guistically, no ultimate distinction can be .drawn between the American Innuit and the American Indian." It is true that both groups of languages are polysynthetic, not agglutinative, as Mr. Dall affirms, but it is doubtful whether all the Indian languages even can be referred to a single source, and certainly the Indian and the Eskimaux cannot be. Nor, again, does Mr. Dall seem to be right in suggesting that the Arctic Highlanders, who have no means of navigation, represent the original con- dition of the Innuit tribes generally ; they must rather be regarded as an instance of degradation and relapse. But he does good service in pointing out the untenabihty of the theory which would bring the first inhabitants of America from Asia, by way of the Aleutian Islands. Apart from the fact that Behring found no traces of inhabitants on the islands named after him, and that the echinus layer in the Aleutian kitchen middens pre-supposes a. population without means for crossing the sea ; " we find that a gap of 138 statute miles separates the Com- mander's Islands from Kamschatka, and another of 253 miles exist between the former and Attu. Here is one of the deepest gulfs known in any ocean, over which rolls a rough, foggy, and tempestuous sea." Three appendices are attached to Mr. Dall' s part of the work : one on the natives of Alaska, another on the terms of relationship used by the Innuit, while the third gives comparative vocabularies of the tribes of the extreme North- West. The first appendix contains the outlines of two grammars, one belonging to the Sitka dialect of the T'linket Indians and the other to the Innuit Aleuts of Unalashka, both by i66 NATURE {June 13, 1878 M. Furuhelm. The second will prove of considerable importance for Eskimaux philology. The most notice- able fact connected with Sitka grammar is that "there are only two cases, nominative and instrumental," and that the instrumental case of the pronouns is employed with active verbs, which means that no true verb exists in the language. The second half of the volume is occupied by an ex- haustive account of the tribes of Western Washington and North- Western Oregon, by Mr. George Gibbs. While the ethnology of these tribes has been treated minutely, their dialects have received the attention to be expected from so able a philologist, and lengthy tables of com- parative vocabularies are followed by a complete Nisk- walli-English and English-Niskwalli dictionary. Mr. Gibbs begins by saying that "in the western district of Washington Territory — that is to say, between the Cas- cade Mountains and the Pacific — there is found, compared with the extent of country occupied, an extraordinary diversity in the aboriginal tongues. Mr. Hale, the ethno- logist, who accompanied Capt. Wilkes's expedition, recog- nised among them eight languages belonging to five distinct families, and to these are now to be added six other languages which escaped his observation. In addition there are several but partially intelligible, even to those speaking the same general language." It is the old story ; the lower we descend the larger becomes the number of dialects and independent tongues which it is the part of civilisation to destroy and unify. The further back we trace the stream of human speech the greater is its diversity, the more manifold its forms. Among the ethnological facts brought to light by Mr. Gibbs, may be mentioned the universal flattening of the skull, the use of the • haikwa shell as a medium of ex- change, and of armour composed of elk-skins or of thin pieces of hard wood. Scalping is unknown, as are also totemism and the division of the tribe into clans, while, on the other hand, "slavery is thoroughly interwoven with the social polity of the Indians of the coast." Earth- works are found in various parts of the district, though they never present the figures of animals, and the existing Indians have no traditions of their origin. But there are clear evidences that the present population of the country is a mixed one, and was probably preceded by a more civilised race. Thus the Makah differ from the Indians of the Sound " in features and habits as much as lan- guage." In fact, the Indians of North America differ among themselves, both physiologically and linguistically, no less than the natives of Europe, and to lump them together under a single name is as rude and unscientific a proceeding as that of the Greeks and Romans, with Avhom all other peoples were " barbarians." If the labours of Mr. Powell and his assistants do nothing more than impress this fact on the student of language and race, they will have effected a good and needful work. A. H. Sayce CULLEY'S PRACTICAL TELEGRAPHY A Handbook of Practical Telegraphy. By R. S. Culley. Seventh Edition. (Longmans, 1878.) THIS well-known book has reached its seventh edition. It was first published in the year 1863, and 190 pages were sufficient to recount its practical instructions. Now 450 pages scarcely suffice to accomplish its purpose. The book reminds one of some old house that has been added to from time to time by different occupiers until it has lost all trace of plan or design. Valuable teachings of experience on one subject are found buried here and there in chapters devoted to other subjects. It is a pity that the author did not thoroughly revise and rewrite his book. It is more like some old housewife's recipe book, full of useful and valuable information, scattered indis- criminately about, than a methodical scientific manual of a grand practical art which has grown within the last few years with gigantic strides. It never pretended to be the result of scientific originality or profound research, but simply to be a practical book intended for practical men. Its great success is more a proof of its want than of its merit. Nevertheless it has merit, and that of no mean order. Commencing with the sources of electricity and the laws of the current, of magnetism and electromagnetism, of induction and of atmospheric and cosmic electricity, it proceeds to describe the construction of a line of tele- graph, both over-ground and under-ground. Modes of testing the various apparatus used, and the systems for signalling'are fully described. Cable working and testing receive very exhaustive treatment. The automatic system of working— the child of Bain and the pupil of Wheat- stone — receive full handling, and the recent develop- ments of the duplex and quadruplex systems receive their fair share of description. The telephone is not neglected, but we must wait for an eighth edition for the later wonderful developments of Hughes and Edison. In speaking of the history of the telegraphic system in this country in his meagre but pithy introduction, Mr. Culley says : — " No assistance whatever was granted by the Government, and it was only after several years of adversity that the undertaking became firmly established." Rather a strange remark from the pen of an officer of a company who owed its foundation to the support of the Government. The first contract of any magnitude ever made by the founders of the company was with the Government, who agreed to pay 1,500/, a year for twenty years, and 1,000/. a year for another twenty years, for telegraphic communication to Portsmouth ; and it was this contract that enabled them to float their concern. However, it is an Englishman's happy privilege to abuse to his heart' s content his own Government for what it does not do, and to ignore entirely what it does do, and we should be sorry to interfere with his prerogative in this respect ; but it is curious to find a Government offi- cial making such a sweeping and erroneous statement as the above in a book accepted by his department as its text-book. It is in the development of submarine telegraphy that England principally shines on the Continent and in America, and it is surprising to find our author omitting all mention of her great deeds in this field. English enterprise in this respect is most marked. English capital is invested in every sea, and EngUsh genius has surmounted every difficulty, whether natural, mecha- nical, or electrical. In 1876 the length of cable laid was 63,990 nautical miles, of which 59,547 ""'ere owned by private companies. There is a great tendency to deny the existence Jwte 13, 1878] NATURE 167 of English inventive genius. The over-shadowing influence of the recent sensational inventions of the telephone and phonograph have led even practica men to believe that inventire power had crossed the Atlantic, but no one Avho reads Mr. Culley's book can fail to learn how much has been done in England. Though duplex working was revived by Hearns, and quadruplex made practical by Edison, neither was invented in America. Cn the other hand, Hughes's beautiful type-printer was born in America, but it was developed in Europe, and its birthplace knows it not. Thomson's syphon recorder, Varley's double-current translator and condenser working, Bain and Wheatstone's automatic systems, fast-speed translators, and all the valuable systems and apparatus in use for testing have sprung from here, and are well described in this work. The Post Office telegraph system, in its technical depart- ment, is a credit to this country and a pattern to the world, and it possesses on its staff some of the most practical electricians of the day. Messrs. Preece, Lumsden, Marson, Gavey, and Kempe are well known everywhere, and though their labours are not acknow- ledged by Mr. Culley, it is well known that they have contributed materially to establishing the tele- graphic system of the Post Office. It is especially in developing the automatic system and in establishing fast-speed translators that the Post Office officials have been so successful. A relay station in Anglesey has increased the rate of working [between London and Dublin from 70 to 120 words per minute. Translating relays working at the rate of 120 words per minute are quite new in telegraphy. Mr. Culley has given scant justice to Mr. John Fuller for his new form of bichro- mate battery, a battery that is coming into very extensive employment for all purposes. It is a zinc-carbon couple, the exciting fluid being Poggendorft"' s mixture. Its pecu- liarity consists in the shape of the zinc, which is per- manently inserted in a bath of mercury. Its electro- motive force is double that of a Daniell's cell, its con- stancy wonderful, its economy great, and its cleanliness and freedom from smell all that can be desired. This work is deservedly popular, not from its literary merit, but from the position of the author and from the great mass of very valuable practical information it possesses. OUR BOOK SHELF Manual of the Vertebrates of the Northern United States, Incltiding the District East of the Mississipi River and North of Noj'th Carolina and Tennessee, Exclusive of Marine Species. By Prof. D. S.Jordan, M.D. Second edition, Revised and Enlarged. (Chicago : M'Clurg, 1878.) The object of this volume is to give collectors and students a ready means of identifying the families, genera, and species of the vertebrate animals of North America. Following the usage of botanists, the author has adopted the system of artificial keys to the classes, orders, families, genera, and species, while use has been freely made of every available source of information. The account of the mammals has been chiefly compiled from Prof. Baird's work, and Dr. Coues has given great assist- ance in the part relating to the birds ; while in this edition the account of the fishes has been entirely re- written in order to include the results of recent inves- tigations in that department. The fact that a work of this nature should in two years' time call for a second edition, is, indeed, a proof of the interest taken in natural science by the American people. This edition seems to fairly represent the present state of knowledge. LETTERS TO THE EDITOR \The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond -with the writers of, rejected manuscripts. No notice is taken of anonymous communications. [The Editor urgently requests correspondents to keep their letters at short as possible. The pressure on his space is so great that it is impossible otherwise to ensure the appearance even of com- tnunications containing interesting and novel facts.l The Phonograph and Vowel Theories Several letters have appeared in Nature bearing on the subject of the phonograph, and refemng to our fir^t communi- cations upon the subject. We are glad to see that our statement as to the reversibility of consonants (Nature, vol. xvii. p. 423) is generally accepted. We feel that as yet the phonograph does not speak with sufficient clearness to determine how. perfect this reversibility is, and that the effect of many minute parts of articu- late utterance cannot be heard with any certainty. Mr. Ellis, in his first communication, ranked the phonograph somewhat too low, but we are more than satisfied with the acknowledgment in his second letter (vol. xviii. p. 38). Mr. A. M. Mayer and Prof. Sylvanus Thompson both speak of the marks on the tinfoil as differing according to the distance of the mouth from the dia- phragm. We do not observe any effect of this kind and see no theoretical reason for any alteration in the relative phases of the simple tones with a change of distance from the mouth. Mr. Mayer seems here to have fallen into an error. We find ample confirmation of Helmholtz's statement that the phase relation between two constituents is not appreciated by the ear. Each per- son usually, but not invariably, adheres to the same phase relation on one pitch, but different people pronouncing the same vowel with approximately the same constituents, combine these dif- ferently, vhich, as Mr. Mayer says, would make reading the marks on the tinfoil a very difficult matter. With reference to the letter by Mr. C. R. Cross which appears in Nature, vol. xviii. p. 93, we adhere with much confidence to the opinion that the five vowels, a ^zt? 7/ (Italian), pronounced in succession, are by contrast at least thoroughly distinguishable when the instrument is run at various speeds, such as to reproduce the sounds at all the pitches within the compass of the average human voice. That no marked change is produced in the relative values of the vowels is con- firmed by the fact that neither in public nor private exhibitions do the hearers of sentences alternately run slow and fast sugge; t that the vowels have changed with a change of speed. This alone would be a sufficient proof that oh does not change into ee, as we understand Mr. Cross to say, and there is no ground, according to Helmholtz's theory, for expecting that it would. To us the relative sounds of the vowels at various speeds seem at least as perfect as those obtained from Willis's well-known experiment, where a .'uccession of vowels is suggested by contrast when the length of a resonating tube is altered. We do not, however, think that our instrument speaks with sufficient distinctness to warrant our expressing an opinion as to the constancy of quality of any single vowel when the instru- ment is run at various speeds. Some ohs remain apparently very constant, and at times we thought that other ohs became brighter or more like " awe." Sometimes we thought ajae became very like " ah." We should be glad to learn the impressions of any of yoiu- readers as to this point. We ventiu-e, however, to remind any one trying the experiment that a low note followed by a high one suggests a change from u (Italian) to/. Thus if we whistle a low note and then the cctave to it or a note near this, the ear is easily persuaded that the whistle resembles u i, but if now, beginning again on the note we just thought was ;', wegoupa-acther octave, the new sequence again suggests u i, although the very note which was last taken to represent i now stands for u. If, therefore, we wish to judge what a sound really is we should not trust much to ontrast, e=pecia]ly when a change of pitch is involved in the ccmpariEcn. 1 68 NATURE \_y7me 13, 1878 We have now obtained and analysed a very large number of vowel curves, especially for the sounds o and u, and with your permission will send a selection of these for publication after the results of our investigation have been communicated to the Royal Society here. These curves show what the voice effects when singing at different pitches a vowel which remains of con- stant quality according to the appreciation of the speaker. The analysis of the curves gives the partial tones of which the vowel sounds are composed, and it becomes a matter of considerable interest to see how far these results confirm or contradict existing theories. We therefore propose to give a short sketch of these theories, hoping that if in error, we may be at once corrected. Prof. Willis showed (Cambridge P/ii/. Soc. Trans., vol. iii.) that, by varying the length of a tube attached to a free reed, he was able to produce the sensation of a change of vowel sound. This sensation is not very definite, especially for the vowels i and e ; but, when the length of the tube is changed rapidly, the ear accepts the suggestion of a change from ti to o, a, e, and i. Prof, Willis concluded that the vowel quality was given in each case by the coexistence of the note proper to the tube with that of the reed, whether the former was or was not harmonic to the latter. One must bear in mind that Willis wrote before it was recognised that all musical sounds are compounded of harmonic partial tones, and also before the function of a resonator was understood. This we may call the absolute single-tone theory. Wheatstone pointed out that the tube used by Willis acted simply as a resonator. F. C. Bonders {Danders' Archiv, vol. i.) observed that when the mouth was formed to speak a given vowel, the cavity had a certain definite pitch of resonance, or maximum resonance, which he determined by observing the pitch of the whispered vowel. Bonders and Helmholtz agree in considering that this charac- teristic pitch is nearly constant in man, woman, and child, for a given vowel. Bonders also observed that the vowels were, in certain cases, accompanied by- a "geruisch" or "whish." Helmholtz attacked the subject in a different way. By means of resonators he applied a qualitative analysis to the sounds which came out of the mouth cavity when a vowel was spoken, and pointed out that a vowel- sound at a particular pitch was charac- terised, not by a single tone, but by many tones. In an early paper, translated in the Phil, Mag. for i860, he describes not only the analysis by resonators, but the synthesis by means of tuning-forks, which is now a familiar experiment. In this paper he appears inclined to believe that it is the relation between the constituent tones which determines the vowel quality ; that, for instance, any pair of simple tones one octave apart will, if properly proportioned, always make an 0. This theory made considerable way ; it is taught with small qualification as to absolute pitch in Tyndall's lectures on sound, and elsewhere ; it may be called the relative-pitch theory. Helmholtz himself does not seem ever to have formulated it, for although the paper referred to distinctly suggests it, he guards himself by saying that the relations observed can only be considered as proved for the particular forks used, and, in fact, his experiments were only made at two parts of the scale. In the " Tonempfindungen" the relative-pitch theory is entirely abandoned, but it is not a little difficult to ascertain what Prof, Helmholtz's latest theory is. This difficulty is indeed admitted by his translator, Mr. A. J. ElHs. By Herr von Quanten, whose papers were published in Pog- gendorffs Annalen for 1875, Prof. Helmholtz was understood to mean that for each vowel one, and in some cases two, tones of definite absolute pitch must be strongly present, these tones being those which Prof. Helmholtz calls the characteristic tones of the vowel. This would imply either that each vowel could only be sung on a very few notes, or that the characteristic tones were present as inharmonic partials. Neither of these conclu- sions i being in accordance with fact, von Quanten concluded that Helmholtz was wrong ; but Mr. Ellis, with justice, as we think, points out that the true conclusion ought to have been that Helmholtz could not possibly have meant to broach an absurd theory. We confess that we were ourselves led to believe at first that Helmholtz taught that each vowel contained strongly either its cha- racteristic tone or some of the higher partials of that tone or tones very near these, and that this was what gave it its distinctive cha- racter. This was the theory which our first experiments seemed definitely to contradict. We now believe, however, that this is not the doctrine taught by Helmholtz. Indeed we fail to find in the "Tonempfindungen" any very complete vowel theory, but we think that the following passage, taken from Bonders' pamphlet "Be Physiologic der Spraak- klanken, 1870," expresses very clearly a doctrine which is very generally looked upon as that of Helmholtz. Bonders says (if our translation from the Butch be correct) : — "Vowels spoken loud are sounds of a determinate timbre maintained unaltered, depending on the form of the mouth- cavity and of the mouth -aperture, and, even without the accom- panying * whish, ' characterised by strong comparatively low upper tones not occurring in a definite order relatively to the prime tone, but for each vowel of an approximately constant pitch." We understand Bonders to believe that on whatever part of the scale a vowel be spoken the pitch or pitches of maximum resonance of the cavity are constant for a given vowel, and that indeed the form itself is constant. This may be called the constant cavity theory, and is taught by Mr. Ellis as the doctrine of Helmholtz. We fail to find that Helmholtz himself has stated this doctrine definitely in all its rigidity, although he accepts the results of Bonders' experiments, and has himself confirmed and amplified them. Almost every statement made by him concerning vowels is limited to those which he could produce by forks forming an harmonic series with Bl> for the prime. Any experiment de- scribed by Helmholtz is of course to be relied on, and so far as we have yet traversed the ground we find that the phonograph gives results in accordance with his experiments as to these con- stituents, but when we examine the one or two more general statements made by Helmholtz we find room for doubt, both as to his meaning and as to the truth or completeness of the con- clusion. Thus at the end of Chapter V. Helmholtz says :— " Vowel qualities of tone consequently are essentially distinguished from the tones of most other musical instruments by the fact that the loudness of their partial tones does not depend only on the numerical order but chiefly upon the absolute pitch of those partials; thus when I sing the vowel A to the note E[) the reinforced tone b"^ is the twelfth partial tone of the com- pound ; and when I sing the same vowel A to the note l/^ the reinforced tone is still b"^, but is now the second partial." The two words marked by us in italics have been introduced for the first time in the fourth edition. This passage might very well be understood to mean that a certain tone of perfectly or at least very approximately definite absolute pitch must necessarily be present in a given vowel. Further examination has, however, convinced us that Prof. Helmholtz does not require the presence of any characteristic tone or of any one of a group of characteristic tones in a vowel. This is made obvious by Chapter VI. In this chapter, which treats of artificial vowels, we find that in order to make an e by tuning-forks Prof. Helmholtz employed B^ and b'\) as "being adjacent to the deeper characteristic tone /'," which in fact lies midway between them ; in the same way he employs /'", a"'[j, and b'"^ for the same vowel, treating all these as adjacent to the higher characteristic tone b'%. Thus the theory of Prof. Helm- holtz is satisfied if tones lying anywhere within a whole octave be present, provided the characteristic tone lie somewhere near the middle of that octave. This is consistent with Bonders' statement of the theory, provided " approximately constant pitch " be allowed to signify anything within six semitones. We consider the following abstract as representing the doctrine taught in the " Tonempfindungen " : — 1 , For a given vowel there is a certain form of mouth cavity which has a pitch (sometimes two pitches) of strongest resonance — as b'\} for 0. 2, If this vowel be spoken or sung on any subtone of this pitch, the overtone corresponding to that pitch will be strongly present, 3, If the same vowel be pronounced at some other pitch then these harmonic partials will be reinforced which lie within, say, six semitones of the characteristic pitch. No opinion seems to be expressed on the following two points : — I, Whether the mouth cavity for a given vowel remains constant when the pitch of the vowel is altered. Mr, Ellis understands Helmholtz to affirm this, which is apparently Bonders' view, but we have failed to perceive any passage in which this is definitely asserted, Helmholtz says the ca,vity for a given vowel has a pitch of strongest resonance, but this is not June 13, 1878] NATURE 169 quite the same statement as saying that when that vowel is spoken at all pitches the same cavity is employed. 2. Whether the mouth-cavities for given vowels are supposed to differ phonetically only in respect of pitch of maximum resonance.. Helmholtz states clearly that in respect of their pitch of maximum resonance they are different, but he does not clearly say whether or no any other differences are essential. There are passages which seem to show that he considers that any resonator of the required pitch (whether in the least like the mouth in shape or material) would answer as well, or nearly as well, as the special mouth-cavity for the production of a given vowel. On the other hand it is at least conceivable that the cavity for, say, o may be very different from that for a in other respects than simply in the pitch of maximum resonance. As to this we find no statement in the " Tonempfindungen." In fine we do not see that Prof. Helmholtz, although he has largely added to our knowledge concerning vowels, has laid down any law by which, given the pitch at which any one vowel is to be spoken, the reinforcement of its constituent tones could be even roughly predicted. This prediction could, however, be roughly made upon the constant-cavity theory, and has been made by Mr. Ellis in his valuable additions to the translation of Helmholtz's work. Prof. Helmholtz seems to do little more than tell us the constituents of a series of vowels sung or said on two notes of one scale, coupled with one peculiarity and in some cases two peculiarities of the resonance cavity. He has avoided all general conclusions except that quoted above, which states that the vowel peculiarity depends chiefly on the absolute, and not on the relative pitch of the partials. In our next communication we hope to be able to state how far the information we have derived by means of the phonograph contradicts, supports, or supplements the above theories. Edinbiurgh, May 29 Fleeming Jenkin ^ J. A. EWING Extinct and Recent Irish Mammals I BEG to thank Prof. Leith Adams for his criticism, in Nature, vol. xviii., p, 141, of my "Preliminary Treatise on the Relation of the Pleistocene Animals to those now living in Eiurope" {Palceon. Soc, 1878), in which, from the nature of the work, it is impossible that mistakes should not be. I cannot, however, plead guilty to some of the mistakes which are placed to my credit: — i. That "the Irish elk is placed among the pre-historic mammals in consequence of its presence in the peat-bogs of England, Scotland, and Ireland." What I wrote (p. 6) was that the presence of the extinct Irish elk in the peat -bogs, which are of well -ascertained pre-historic age, renders it impossible to accept Sir Charles Lyell's definition of the term recent, in which no extinct species are stated to occur. Of course the Irish elk, as Prof. Leith Adams remarks, has long been known to be met with, almost universally, in the lacustrine marls underlying the peat, and it is thus described in p. 27 of Mr. Sanford's and my own Introduction [Palcson. Soc, 1866). I do not know of its occurrence anywhere in peat, but at the bottom of peat-bogs, to which the bones of animals suffocated in the peat in all probability gravitate. It seems to me very unlikely that all the remains at the bottom of peat-bogs belong to a period before the peat was accumidated. 2. I have never held, and still less to my knowledge printed, that "man and Irish elk, reindeer, mammoth, horse, and bear, were contemporaneous in Ireland." Evidence of palaeolithic man, the contemporary of the mammoth in Ireland, is, so far as I know, altogether wanting. If Prof. Leith Adams will kindly write me a reference to any such statement of mine it shall be corrected at once. My list of Irish animals, which merely purports to give the principal historic mammalia, does not profess to give all the mammalia, which will doubtless be fully treated in Prof. Leith Adams' promised work. W. EoYD Dawkins Owens College, Manchester, June 9 Alternate Vision Mr. Galton's remark (Nature, vol. xviii. p. 98), that "sometimes the image seen by the left eye prevails over that seen by the right, and vice versd," leads me to describe a curious defect in my own eyesight, which in a different way confirms what he says. While my right eye is fairly long-sighted, my left eye is very short-sighted. For instance, the focal distance of my right eye for your leader type is 18 inches, and for the left eye only 8^ inches. For your letter type the focal distance for the one is 16 inches, and for the other 6| inches. This is by the light of a Duplex lamp, and by focal distance, I mean the distance at which I can see distinctly. The result of this in- equality in my two eyes is that the right — or long-sighted one — involuntarily closes when I read, and I am not aware of its being shut, except when some one who is a stranger to the peculiarity calls attention to it. During the day, however, in looking about both eyes are generally open, though when I look intently at a distant view, I find the short-sighted eye shuts occasionally. But in a general way both eyes are open, and I have two distinct images presented to my brain, one blurred and indistinct, even for faces a yard distant, and the other clearly defined, I believe, to the usual distances. How is it that my brain or mind rejects the blurred image and chooses the distinct one, so that- 1 see everything perfectly clearly. If I get a piece of dust in the good eye, or close it, I immediately see the bliured image, and if this take place in the street, it causes a painful degree of confusion as to distances, &c., so that I am often brought to a standstill by such an occurrence. That both images really are presented to the brain I know. For instance, in travelling by train I frequently amuse myself by placing my eyes so that the short-sighted eye sees a portion of a scene through the window, without the good eye being able to see it. Then I see the blurred image only ; but as the train moves the blurred is replaced by the bright one, as the good eye gets to work. The blurred image always appears at a higher level than the other, and it is the same when I shut my good eye for a moment and look at the fire with my bad one. On reopening the good one the blurred fire appears slightly above the bright one, and the latter almost instantly drives the indis- tinct image away — like a dissolving view. Things appear, as a rule, much flatter to me than to people who enjoy binocular vision. I know this because I have a pair of spectacles so arranged as to equalise my sights. When I put them on, objects like trees put on a delightful fulness and roundness to which I am usually quite a stranger, and the effect is most charming. I may add that two of my brothers have a similar defect of vision. May 31 J. I. R. The Eskimo at Paris I HAVE read with great interest in vol. xviii. p. 16 of your re- nowned journal the article concerning the Eskimo, the exhibition of whom in Paris, &c., has recently made so great a sensation. Unfortunately, it seems to me, the writer of the article, M. A. Bordier, has been incorrectly informed with regard to the introduction of these people. It is not to Mr. Geoffrey St. Hilaire, the director of the Paris Jardin d'Acclimatation, but to M. Charles Hagenbeck, the well-known and intelligent dealer in wild animals of our town, to whom science is indebted for the intro- duction both of the Eskimo, the Hamran and other types of the different tribes of Nubia, and the Laplanders. I should be much obliged to you if you would kindly insert the above correction in an early number of your journal. Hamburg, May 28 J. D. E. Schmeltz The Telephone Having seen a paragraph in Nature communicated by Mr. Severn, of Newcastle, New South Wales, describing a method of using a telephone to enable deaf persons to hear, I have tried the experiment in the manner Mr. Severn describes — by fastening a string to the parchment diaphragm of a simple telephone made of wood, and carrying this string round the forehead of the deaf person, who clasps the string with both hands and presses them over his ears. The experiment in this way was partially successful ; the sound of the voice was always heard, and some words were distinguished. Afterwards I fastened a single string to the telephone and got the deaf person to hold the string be- tween his teeth. He then heard every word distinctly, even when spoken in a low tone of voice at the whole length of the room. 63, Strand, W.C. John Browning Till now I have looked in vain for any account in Nature of experiments with the telephone or phonoscope, inserted in the circuit of a selenium (galvanic) element (see Nature, vol. xvii. p. 312). One is inclined to think that by exposing the selenium to light, 170 NATURE [J tine 13, 1878 the intensity of which is subject to rapid changes, sound may be produced in the phonoscope. Pi-obably by makinj^ use of selenium, instead of the tube-transmitter with charcoal, &c., of Pi-of. Hughes, and by exposing it to light as above, the same result may be obtained. I should be glad to know whether experiments have been mide in this direction ; for if the above should prove true, there is no doubt that many applications would be the result. Kew, June 3 J. F. W. Meteor Having ju.^t seen a magnificent meteor, I send you an account of it, as from its position it may have been seen at Gibraltar. At 7.33 this evening a large meteor appeared as nearly as possible N.E. by E. of my position, at about 25 to 28° from the horizon, in a wide opening in the clouds, and pro- ceeded with a moderately fast motion towards the north, slightly descending in a path slightly concave to the horizon. I did not see it disappear, as it went behind some bushes which hid the sky between N. by W. and N. by E. ; if it disappeared due N. it would have been about 20° from the horizon as estimated by the altitude of the pole-star. The appearance was very remark- able, the head being of a brilliant green and the tail bright red. When I first saw it I took it for a first-class rocket passing at about 300 or 400 yards from me with a bright Bengal light of green colour at its head. The brightness was certainly from 10 to 15 times that of Venus at its brightest. It shone in the twilight more brilliantly than lever saw Venu; against a dark sky. The tail was not persistent as far as I could judge, against tha light sky, and no rejiort was heard, though I li ;tened for several minutes, A bright star, which I believe was Vega, was just below it among the clouds, and afforded a fair standard of comparison ; it was from thirty to forty time^, at least, brighter than this star. W, A. Sanford Funchal, May 27 P.S. — I find that I have forgotten to mention that my position is about two miles south-west of the cathedral of Funchal. Multiple Rainbow On Saturday evening I (and others) observed a rninbow ^^•hich presented a very peculiar phenomenon, 'lire primary bow, in the neighbourhood of its apex, was apparently composed of three distinct bows. Just below the violet of the principal bow the bright portion of a second bow was observed, and at about half the distance between the bright portions of these two bows was observed the bright portion of a third bow. The secondary bow looked much as usual, and the principal primary bow was very perfect, so far as I could see, on each side. The repetitions of the primary bow extended only through an angle of 35° or 40", and did not apparently end at the same point. Between the point of observation and the sun are some pieces of still water in Bu.-hey Park. Overhead were some clouds upon which the sun was shining. I think the phenomenon was due to the reflection of the sun from the cloud?. R. S. Hampton Wick, June i Opening of Museums on Sundays Many of your readers will be glad to know that the very admirable and extensive museum at Maidstone was opened to the public on Sunday last, and will in future be open on Sunday afternoons from two to six o'clock. The opening was a great success : the mayor and many of the influential inhabitants were present, and moi-e than i,oco people vi.-ited the museum on that afternoon, the average attendance on week-days being from 50 to 100. The most perfect order was preserved, and every part of the museum received its share of attention, even the library being more than full of readers. I believe that this is the first and only scientific museum that has yet been opened on Sunday in the United Kingdom, the Art Gallery at Birmingham and Aston Hall being of a different cliaracter, and so I have thought it worth Avhile to call your attention to it. For the sake of those who have not yet visited Maidstone Museum I may say that it is one of the best local museums in the country, having remarkably fine pala^ontological, concho- logical^ and other collections ; that it will well repay a visit, or more than one ; and that Mr. Bartlett, the c3urteous curator, IS always ready to give visitors any assistance that he can. Maidstone itself, and the country round, are well worth visit- ing. I must not forget to mention the cemetery, which is one of the most beautiful in the countiy. ID, Bolton Row, Mayfair, W., W. H. Corfield, June 10 Chairman of the Committee of the Sunday Society THE FISHERIES OF BRITISH NORTH AMERICA I. T T was provided by the Treaty of Washington, that, on ■*■ payment by the United States of a compensatory sum (to be determined by a Commission) to the Dominion of Canada, the Fishing-grounds of British North America should be entirely thrown open to the fishermen of the Union ; those of the United States coast, on the other hand, being opened to the fishermen of the Dominion only as far south as the 39th parallel of N. lat., which is almost exactly that of Washington. While the payment of the compensation since awarded by the Commission is being protested against by not a few influential politicians in the United States, the probable influence of the Fishery clauses on the future of the Dominion of Canada is being carefully considered in those parts of it which they espe- cially affect ; and we have before us a very abki report on this subject by Mr. H. Y. Hind, M.A., a Member of the Legislature of Newfoundland, of which, as bised on a careful scientific study of the physical and biological conditions involved in the questions at issue, we think that a summary will prove interesting to our readers. It is somewhat startling to be told that "as a maritime power the Dominion of Canada stands fifth among the nations of the world." This expression, however, is obviously meant by Mr. Hind to refer, not to its armed but to its commercial marine, which is only surpassed by that of the Mother country, of the United States, of Norway, and of Italy. Its vessels number more than 7,000, and their registered tonnage amounts to above a million and a quarter tons, increasing at the rate of 60,000 tons per annum ; its supply of trained seamen is drawn from a fishing population scattered over 3,000 miles of sea-board ; and the annual value of their catch reaches at least 20 millions of dollars. The political importance of sea-fisheries as a nursery for seamen, irrespective of the pecuniary value of the catch, is ad- mitted on all hands ; and hence it is that a far-sighted policy looks to the value of the British American Coast fisheries as consisting not only in their present produc- tiveness, but also in the security they afford for the main- tenance and permanency of what has of late become one of the greatest industries of the Dominion — the work of ocean-carrying. Now, while the length of the coast-line in British America not covered by previous treaty-arrangements, which is now opened to the United States fishermen, is about 3,700 miles,and the area of its coastal fishing grounds is about 1 1,900 miles, the length of the United States coast- line opened to British fishermen, is only 1,030 miles, and the area of its fishing-grounds about 3,500 miles. But the respective values of these grounds are not to be estimated by their relative extent alone ; for while the United States fishing-grounds north of the 39th parallel were formerly extremely productive, they are now much less so, chiefly through the improvidence of their own people; the cod-fishery, in particular, having been ruined in a great measure beyond repair. On the other hand, the United States coastal waters south of the 39th parallel still maintain much of their original productiveness, supplying a very large quantity of fish to the markets of New York and the South. But to these prolific fishing- grounds access is forbidden to British-American fisher- men, who are thus placed at a great disadvantage com- pared with those of the United States ; the latter being June 13, 1878] NATURE 171 able,r\vhen the approach of winter makes the fishing industry of the Dominion coasts hazardous or impracti- cable, to start at once for the southern grounds, where they can pursue their calling through the winter months. This is so great an advantage, that it frequently renders a northern summer fishery remunerative, which would not be so if the fishermen were dependent upon it alone. The fish which frequent the United States coast-waters south of the 39th parallel are chiefly of the "anadro- mous" kind — that is, they live for most of the year in the sea, where they attain the greatest part of their growth, running up into fresh waters for the purpose of spawning. The chief among these are the shad, the alewife or fresh- water herring, the rock-fish, and the striped bass. On the other hand the "commercial " fishes — the cod, her- ring, haddock, hake, halibut, and mackerel — are found in greatest abundance where the temperature is kept down by the Arctic current, which at the same time fur- nishes their great store-house of food, and the temperature congenial to them. On the fishing banks of the open sea, th e abundance of hake and cod depends essentially upon the resort of herrings; but it is by the "anadromous" fishes that the cod is attracted in-shore. And the destruction of the cod-fisheries which formerly existed on the New England coast is attributed by the United States Fisheries' Commission to the comparative annihilation of the " anadromous " species, through the obstruction and contamination of the river-waters by the various land- industries established along their banks. Below the 39th parallel, however, the "anadromous" fishes find an accessible winter' s home in the warm water off the coast of the Southern States, and enter its rivers to spawn as early as February, The United States fisher- men being privileged to follow them thither, are thus placed in a position of great advantage as compared with those of the Dominion ; the enterprise of the former being stimulated, while that of the latter is cramped, by the Fishery-clauses of the Treaty of Washington, which, as Mr. Hind points out, " place an obstructive boundary on the operations of the British-American fishermen far more limited and confined than formerly existed under the Reciprocity Treaty, while in the same breath they remove every impediment to perfect freedom of action to the United States fishermen throughout an area of great productiveness and practically unlimited extent." The Physical conditions under which marine life exists on the coasts of British North America, differ in this important particular from those which prevail in the seas of Northern Europe — that while the great modify- ing influence of the latter is the warm N.E. flow, popu- larly known as the Gulf Stream, the former are chiefly dominated by the Arctic Current, which brings down glacial sur/ace-\iAiQr from the coasts of Greenland and Labrador. The existence of a low bottom-ttm'peratnre, wherever the basin is deep enough to admit the Arctic under-flow, is common to both : but while, on the European side — to take as an example what I have called the " Lightning" channel that lies N.E. and S.W. between the Orkney and Shetland Islands and the Faroes — the glacial under-flow from the N.E. is overlaid by a com- paratively warm upper-flow from the SuW., on the American side the glacial under-flow from the N.E. is overlaid by a cold upper-flow from the same quarter, urged southwards by the prevalence of northerly winds along the Greenland and Labrador coasts. And alike in the upper and in the under south-moving strata is there a westerly tendency (caused by the deficiency of easterly momentum which they bring from latitudes higher than 60° into lower parallels) which causes them both to "hug the shore " along the whole coast-line not only of British North America, but of the United States. The super- ficial Arctic wind-current cannot be distinctly traced further south than New York ; but none the less is there a band of cold Avater intervening between the coast-line of the Southern States and the Gulf Stream; and the Challenger soundings have distinctly shown the con- tinuity of this band with the deep Polar under-flow which underlies the Gulf Stream, and surges up on the western slope of the Atlantic basin. The course not only of the superficial Arctic current, but probably also that of the deep under-flow, is greatly modified by local conditions ; that of the former chiefly by the strong tides and local winds of the coast, especially in estuaries, straits, or inlets ; and that of the latter by variations in depth — the effect of a shallowing bottom being to bring the cold under-flow nearer to the surface. And thus, as Mr. Hind observes, the extraordinary varia- tions which present themselves on the Dominion Coasts are specially worthy of study in their relation to Fish-life. No such peculiarity is more remarkable, than that which seems almost constant in the Strait of Belle Isle, sepa- rating the north end of Newfoundland from Labrador ; for here, in the latitude of London, the sea has a glacial temperature all the year round. Pack-ice remains in these Straits through the early summer, with a compara- tively high air-temperature ; and they are never clear of bergs. Sometimes the surface freezes over again at Midsummer after the breaking up of the winter ice. In 1873 the surface- temperature of the sea in these Straits on four consecutive days in the latter part of June was found to range from 36° to 28° ; the air-temperature during the same time ranging between 43° and 68°. The extremely little influence which this comparatively high air-temperature' had upon the temperature of the surface water, clearly shows that the latter must be constantly kept down by melting ice, and also by the surging-up of the deep glacial underflow. Numerous cases are cited by Mr. Hind of the influence of winds and tides in lowering the surface-temperature by mixing the deep cold stratum with the superficial ; the general rule being that easterly sea-winds generally raise the temperature of the surface- water, while westerly winds cool it. That such changes (as from 52° to 38° in a single day) have no relation to the temperature of the winds themselves, is clearly shown by comparative observations of the sea- and air-thermo- meters ; the moist easterly sea-winds being generally colder (at least during summer) than the dry winds crossing from the land ; while the influence of a shoaling bottom,, lying in the course of the deep glacial flow, is shown by a sudden descent of the surface-temperature to 33°. So, again, a mixing of the different strata produced by cur- rents along the shoaling waters of the Labrador coast, particularly among the islands, rapidly reduces the tem- perature ; so that, in a cold calm after a storm in December, all the conditions are present for that forma- tion of "anchor-ice," of which Mr Hind gave an account in a former communication. " The sea on the shoals is uniformly cooled ; a clear sky and a north wind assist the radiation of heat ; and ice-spicules form with great rapidity in the Labrador current, often increased in local intensity by tides." It has been lately stated, on the authority of Prof. Mohn, as a fact well known to the Norwegian fishermen, that the deep water is often so cold that it freezes if disturbed, although it continues liquid so long as it remains perfectly still ; fishes passmg into such a glacial stratum being frozen, and coming to the surface as lumps of ice. Mr. Hind draws attention to a remarkable series of observations of temperature and specific gravity, taken by Dr. Kelly, of Quebec, during the Admiralty Survey of the Gulf of St. La'wrence in 1830-36; which show that a very curious temperature-stratification exists in that vast estuary, obviously produced by the mixing of the great body of fresh water brought down by the river St. Law- rence with the cold Labrador current. A zone of water of a certain degree of warmth is superimposed upon a zone sometimes of lower and sometimes of higher temper- 172 NATURE \ytine 13, 1878 ature ; and these zones are cup- or saucer-shaped, having a general relation to the depth in different parts of the Gulf, and sometimes coming to the surface at variable distances from the coast. In every case, however, the relative position of the zones is strictly accordant with their relative specific gravities j the overlying of a warmer by a colder zone being due to the dilution of the latter by the admixture of fresh water, as appears from the fol- lowing examples : — I. ir. III. Temp. Sp. Gr. Temp. Sp. Gr. Temp. Sp. Gr. Surface 5 fathoms 54 1-0225 43 I'oig 51 42'5 i-oi8o 10 ,, 20 „ 30 „ So rt 46 34-5 34 — 37-5 39 33 1-023 I -0246 I -026 38 32-5 33 34 1-0261 1-0266 1-0266 lOO ,, 150 .. 37 I '0370 36 1*0275 35 35 I -0271 1-0278 A similar alternating temperature-stratification has been recently observed by the Norwegian Expedition in the seas between the coast of Norway and the Faroes ; and I venture to predict that when the temperatures of the suc- cessive strata shall hare been correlated with their respective salinities (which are modified by the admixture of fresh water discharged from the Norway fiords), the stratification will be found conformable to the same law of the heaviest water lying deepest. There is one locality not far distant from our shores, in which similar influences have been found to pro- duce equally decided, though less strongly- marked effects ; I refer to the Baltic Straits, in which very careful observations of teitiperature and specific gravity have now been carried on for several years under the able direction of Dr. Meyer of Kiel, and his coadjutors. Here there is an admixture of waters from three different sources — the North Sea, the Baltic, and the underflow of glacial water which is brought as far south as the Skagerrack by a comparatively deep channel lying outside the Norway fiords. The North Sea brings water of ordinary salinity and of a temperature corresponding generally to that of the air : the Baltic outflow brings a variable quantity of water of low salinity : and the deep Norwegian channel brings water of very low tempera- ture. In addition to these factors, there is the operation of winds and tides, which greatly modify the movements alike of the superficial and of the deeper strata. These influences are now so well understood, that, by a careful correlation of them, the temperature and salinity of the waters at the various observing-stations may be closely predicted; very small differences in specific gravity on the one hand, or small variations in level (and there- fore in downward pressure) produced by winds and tide?, being sufficient to determine movements in great masses of water, tending to the restoration of the dis- turbed equilibrium. In fact, as Dr. Meyer assured me during a recent visit to this country, "Your trough- experiment is being daily carried out on the great scale in the Baltic Straits, with the like results." It is now well-established that the Temperature-stratifi- cation of the Sea has, as Mr. Hind says, a7i all-i7nportant bearing on the great fisheries : — " It determines the ver- tical positions in the sea, of the zones of minute and microscopic life which constitute the food of the higher forms, up to those of the fish Avhich feed either directly or indirectly upon them." The cold of the Arctic seas is commonly supposed to be inimical to animal life ; but hat the very contrary is the fact, is shown by the abun- dance of fish along those parts of the British North American coast, whose waters are most reduced in tem- perature by the Greenland and Labrador current, as compared with their paucity along the New England shores, which are less affected by that current. The most noteworthy case is that of the Strait of Belle Isle, in which, though almost every square mile has been an- nually fished for more than two centuries, continued pro- ductiveness is the rule through an average of years. And thus it becomes clear that the relative extent of the cold- water areas which feed (so to speak) the several fishing- grounds of the North American coast, must be a factor of the greatest importance in determining their respec- tive values. Thus, while the water-area within the 100 fathoms' line along the coast of the United States north of Cape Hatteras does not exceed 45,000 miles, that of the British-American coasts within the same limit of depth exceeds 200,000 square miles. And while the former is bounded more or less closely by the heated w^ater of the Gulf Stream, which invades it during the summer months by a swing towards the shore, the latter is only bordered by the Gulf Stream along its southern edge, and is continuous to the north and north-east with a limitless sea of cold water, which is the home of those minute forms of marine life that constitute— directly or indirectly — the source of our "commercial" fishes, the cod, herring, and mackerel. Another advantage possessed by the fishing-grounds of British North America over those of the United States, is their immunity from the ravages of the blue-fish — a vora- cious wandering fish, whose home is in warm southern waters, its northward migration taking place only during summer, and never extending far beyond Cape Cod. Its destructive agency has had much to do with the dimi- nished productiveness of the New England fisheries; and further south is specially exerted on the mackerel schools. According to the estimate of Prof. Baird, the United States Fishery Commissioner, the weight of fish consumed by the blue-fish of the United States coast during the season is about 300,000 inillion pounds. In its turn the blue-fish is largely consumed as an article of human food, being taken in great numbers along the coast of the Southern States ; but it is not suited for salting, and is consequently of no value as an export fish. From the fishing-grounds in which the blue-fish is taken in immense quantities during the early winter months, for the supply of the northern markets, British American fishermen are excluded. Of the influence which Temperature has now been ascertained to exert over the habits (especially the migra- tions) of these fishes, and consequently over the produc- tiveness of the great " harvest of the sea" furnished by them, as to which a valuable mass of information has been brought together by Mr. Hind, I shall give some account in a future communication. William B. Carpenter THE MICROPHONE "■ THE following expei-iments were suggested by the description, which appeared in a recent number of Nature, of the microphone lately invented by Professor Hughes. Instead of the pointed piece of carbon sup- ported between two pieces of the same material as used by him, it occurred to me that ordinary gas cinders would be likely to answer the purpose tolerably well. To test this, I included in the circuit of an ordinary Bell telephone, a single Leclanche cell, and a small jelly can half filled with cinders broken into pretty coarse frag- ments. The connections were made by slipping down at opposite sides, between the cinders and the sides of the I Abstract of a paper read before the Royal Society of Edinburgh on June 3, 1878, by James Blyth, M.A., F.R.S.E. Jtme 13, 1878] NATURE 173 jar, two strips of tin, to which the circuit wires were attached. When the simple instrument was used as a transmitter, articulate sounds were heard very loud and distinct in the distant telephone, though occasionally marred by what appeared to be the rattling of the cinders in the jar. With this transmitter sounds were also quite audible, even when the speaker stood several yards away from it. I next took a shallow box, made of thin wood, about fifteen inches by nine inches, and filled it with cinders, taking care, in the first place, to nail to the inside of its ends two pieces of tin to which wires could be attached. Having nailed down the thin lid of the box, and included it in the circuit of the telephone, along with one Leclanche cell, I found that it made both a very sensitive micro- phone, as well as an excelleiit transmitter for the ordinary telephone. With three of these boxes hung up like pictures on the walls of a room, and connected in circuit, almost any kind of noise made in any part of the room was revealed in the telephone. Speaking was heard distinctly, and a part-song by two voices in the middle of the floor was rendered with surprising clearness and accuracy. In my next experiment, still using the same cell in the circuit of the telephone, I tried as transmitter a single elongated cinder with the wires Avound tightly round each end. Sounds uttered close to this cinder were quite audible, but I failed to hear them when I substituted for the cinder the carbon of a Bunsen cell with brass clamps firmly attached to each end, into which the circuit wires were screwed. Possibly either the more porous and friable nature of the cinder or the comparative looseness of the wire attachments, may have had something to do with this difference of effect. I next removed the Leclanche cell from the circuit and used as transmitter the jelly can containing dry cinders. I sometimes fancied that I heard sounds even with the cinders dry, but they became faintly, though distinctly, audible when the cinders became slightly moistened by the breath of the speaker. However, on pouring water into the jar, so as almost to cover the cinders, the sound was heard on the telephone almost as well as when the Leclanchfe cell was in circuit. I did not, however, hear any sound with the cinders removed and water only in the jar, not even when the conducting power of the water was increased by being slightly acidulated. In my next experiment I tried if the jar with the cinders would act as a receiver as well as transmitter, and was not a little surprised to find that it did so. For this purpose I used similar jelly cans, containing cinders both for transmitter and receiver, and included a battery of two Grove's cells in the circuit. Articulate sounds uttered in the one cinder jar were distinctly heard in the other, and even voices could be distinguished. How- ever, the results were not so good as I have no doubt they will yet be, when better forms both of transmitter and receiver are adopted. Here we have the beginning of a kind of telephone worked entirely by the electric current without the aid of magnetism. I also tried successfully an ordinary telephone as transmitter and a cinder jar as receiver, but in this case, the sounds were some- what fainter and not so easily distinguished. I re- marked, also, that when an intermittent current was sent through^ the cinder jar, a very distinct rattling noise issued from it. In order to find out if the cinders in the receiving jar were atall jostled about when sounds were beingtransmitted to it from a similar jar, the following experiment was tried. A strong battery was included in the circuit, and a clean glass jar containing cinders taken as receiv- ing instrument. When this was taken into a dark room small flashes of electric light were observed here and there amongst the cinders while sounds were being sent. James Blyth RESTING SPORES A VERY interesting memoir by Dr. Wittrock, the ■^~^ well-known Swedish botanist, was communicated to the Swedish Academy of Sciences in December last " On the Spore-Formation of the Mesocarpeas and especially of the New Genus Gonatonema." The chief interest of this memoir seems to us to He in its somewhat novel interpretation of some pretty well-known physio- logical facts, which we shall as briefly as possible proceed to enumerate. In one lovely group of green-coloured algae we find a number of very pretty species, many of which consist of one-celled forms, and others of which, obeying a law of cell growth, not only produce new cells but also cause these to adhere to one another and so, as this growth goes on, give a chain-like or filamentous appear- ance to the mass. These filamentous green freshwater alga^ are very common. Dillwyn, in the beginning of this century, knew and described many of them, and he also seems to have well known that the contents of some of their cells formed oval bodies called resting spores. The merit of having worked out the history of these spores belongs to Prof. A. de Bary, from whose researches it was first made clear that in some of these forms (Zygnema) one of the chains of cells will come to lie alongside of another chain, and then the cell- wall of two opposite cells will grow outwards until they meet. On meeting the; tips of these outgrowths will be absorbed, and the two cells will thus communicate by means of this newly- formed canal, whereupon it will follow that the contents of both cells will each go half way to meet the other, and their conjoining will take place in the newly-formed canal, or sometimes in one of the cells ; or that the whole of the contents of one of the cells will pass over and com- bine themselves with the contents of the other. In either case the result will be the formation of a new body— well known as the zygospore, but also known under many other denominations. But, again, in other forms (Mesocarpus), while the initial process will be the same so far as the formation of the cross channel goes, the further steps differ much, it being only the green-coloured portions of the protoplasm of both cells that move over into the canal, whereupon the central portion of this green mass, composed of about equal parts of the contents of the two cells becomes developed into a zygospore, leaving the rest of the cell- contents to fade away. The physiological import of these two quite different phenomena was therefore this : in Zygnema and its allies the total contents of two of the cells were required to form a zygospore — whereas in Mesocarpus this was formed out of only portions of the cell-contents. There is thus no strict analogy between these two forms of zygospores, and they probably should not both receive the same name. De Bary perceiving this, referred to the one as resting-spores formed by the partition of the zygospore [the parts destitute of green contents having been par- titioned oftj, strangely applying this term to that stage when the two cells had combined to form one, and to the other as resting-spores without partition. De Bary's attempt at being logical has apparently been overlooked by many writers on this subject, notably by such eminent investigators as Max Cornu and Sachs, who still apply the term zygospore to both forms, but Pringsheim has grappled with the difficulty in his most thoughtful paper " On the Alternation of Generation in Thallophytes," and suggests that the first stage in the reproductive process in Meso- carpus is the ^' conjugation "-stage — here the cells join and become, so far as their cell-walls are concerned, united into one. The next stage is the more important one, in which the cell-contents commingle, and the result is the production of the central cell — a carpospore — and of two or four cells which surround it, and form the equivalent of a fruit-like body, or sporocarp, 174 NATURE {June 13, 1878 and of course it would make no matter whether this sporocarp were formed in the connecting canal as in Mesocarpus, or whether it fills this and extends over into both the cells as in Staurospermum, or as in Plagio- spermum is altogether formed in one of the cells ; the essential feature being the differentiation into the carpo- spore and its investing covering the sporocarp. Now Dr. Wittrock has made the rather startling observation that in one and the same species (^Mougeotia calcarea, Clev.), the formation of the spores may take place equally in the manner of the three above-mentioned genera ; also that occasionally even the spores may be formed without any conjugation, and further that in a plant found growing last October in an aquatic stone house in the Upsala Botanical Gardens, and which is described as Gonatonema ventricosum, the spores are formed in a neutral way through the agency of cells never intended for and incapable of conjugation. Such spores the author calls agamospores, and he finds a second species of this new genus in Hassall' s anomalous Mesocarpus notabilis. This memoir of Wittrock's will be found in the Bihan^iill k. Svenska Vet. Akad. Handliitgar, Band 5, No. 5, 1878. It is written in English, and illustrated with a plate. Upon it the following observations may not seem alto- gether out of place. If the interpretation placed on the phenomena to be witnessed in the Mesocarpeae by Prof. Pringsheim be accepted, then this family can scarcely be left among the Conjugatae, and this would hold true also of Wittrock's new genus, as indeed is so stated by himself. But may not the phenomena be interpreted in yet one other way .'' First, as to the agamospores in Gonatonema. Is it beyond the bounds of possibility that, despite their ex- ternal likeness to zygospores, these are simply vegetative spores, to be compared to one of the so-called tetraspores in Florideae ? They surely cannot be compared to any form of organism itself the product of the commingling of the contents of two different ceils ! Another sugges- tion, to account for this agamospore, has been made to me by my friend William Archer. It is that there may have been a separation between the upper and lower portions of the protoplasmic contents of the same cell, and that these, without waiting for the formality of forming separate cells, may have then and there con- jugated. This is certainly a most ingenious suggestion, and is strengthened by the well-known fact that, in some Desmids, after the single-celled frond has divided into two halves, and before the newer portions grow into any- thing like the similitude of the older portions, the two halves, which were only just parted, will conjugate and form an ordinary zygospore. De Bary gives some pretty figures of this strange phenomenon, which, according to Mr. Archer, might be carried one step further, and there be no parting at all. In favour of my own idea I can only add that the first origin of what, in some of the Florideas, will form the tetraspores, and the origin of these agamospores, appear to me to be the same. Next as to the sporocarps in Mesocarpus. The differentiation into sexual entities of the protoplasmic contents of cells is con- fessedly, at first, scarcely perceptible. It would be impos- sible, in many cases, to say with any confidence, this one is the germ cell, and that one is the sperm cell. But gradually a differentiation appears in that the contents of the former exhibit themselves as passive, and of the latter as active ; the contents of the one remain quiescent, those of the other pass over to conjugate with the former, but all through the contents that commingle are almost in every case alike in quantity. Carry the differentiation a step further on, and we find that the contents that commingle rnay be at first somewhat, and then be strikingly un- like in quantity. The passive contents will be divided into a comparatively small number of portions (in Fucus eight), but these each can be fertilised by the very smallest portion of the active contents. Now may not the Meso- I carpeae be a link between these groups ? The contents of each of the two cells divides into certain portions. The fertilising power of the active contents is not sufficient for the passive contents, and hence but one portion — that the most specialised — is fertilised ; this forms the zygospore ; the other portions remain sterile. Then this spore would differ from the zygospore of Zygnema just in the same proportion as it would differ from the oospore of Fucus, but the fructification would not at all be a representative carpospore, and the at first sight very anomalous case of M. caicarea may be explained by supposing that the number of partitions is a matter of but secondaiy im- portance, unless the fertilising power of the active con- tents were to increase. This field of research is an important one, and much as we are indebted for infor- mation on these points to the labours of the Swedish botanists, we must still continue to look for fresh facts and new explanations. E. Perceval Wright PROF. C. F. HARTT^ CHARLES FREDERIC HARTT, whose death by yellow fever occurred at Rio de Janeiro on the i8th of last March, was born at Fredericton, New Brunswick, August 23, 1840. For three years and a half before his decease he had successfully withstood the fatigues of exploration and the labours of organising and carrying on the geological commission of Brazil, an undertaking beset with many trying difficulties. Prof. Hartt's connection with natural history dates from boyhood. Encouraged by Prof. Cheesman, he made rapid progress in his favourite studies, without, however, neglecting the other branches of learning. But his particular bent always lay toward natural history, language, music, and art. While a student at Acadia College, he undertook, under the direction of Dr. Dawson, extensive researches into the geology of Nova Scotia, which province he ex- plored on foot from one end to the other. In i860 he accompanied his father to St. John, there to establish a college high-school. This change of location brought him into another field for exploration, that of the geology of New Brunswick, and he commenced his new labours at once. The Devonian shales at the locality called Fern Ledges, in the vicinity of St. John, were the prin- cipal objects of his research. After a long siege of hard work he was amply repaid by discovering an abundance of land plants and insects, of which the latter stiU remain the oldest known to science. Prof. Agassiz was attracted by this last discovery of the young Canadian naturalist, and invited him to enter his museum at Cam- bridge as a student. This he did in 1861. Each vaca- tion he returned, either to New Brunswick or Nova Scotia, to continue his explorations. In 1864 Mr. Hartt was employed, with Profs. Bailey and Matthews, on the geological survey of New Brunswick, and, while en- gaged in this work, obtained the first full proof of the existence of primordial strata in that province. Many of his discoveries in Nova Scotia and New Brunswick were published in the Provincial Government reports, and also in Dr. Dawson's "Acadian Geology." Upon the organisation of the Thayer Expedition to Brazil, by Prof. Agassiz in 1865, he was appointed one of its geologists, and henceforth to the time of his death he was ever a most devoted investigator of South American natural history. Aided by New York friends he returned to Brazil alone in 1867, this time examining with the greatest care the reefs of the Abroihos Islands, and those of the coast, as well as the geology of a part of Bahia and Sergipe. The results of his work thus far were pub- ' From an article by Mr. R. Rathbun in the Pojinlar Science Monthly forr June. June 13, 187S] NATURE 175 lished in 1870 as the " Geology and Physical Geography of Brazil." In addition to the account of Hartt's re- searches, it included the best results of all who had ever published on the geology of the country. Early in 1868 he "was elected Professor of Natural History in Vassar College, and shortly after of Geology in Cornell University. In 1870, with Prof. Prentice and eleven students of Cornell University, he again went to Brazil. He entered the Amazonian Valley, hoping there to discover, at the falls of the different tributaries of the Amazonas, other fossiliferous formations than the creta- ceous, which latter alone he had found along the coast. He was well rewarded, and returned to the United States with large collections of fossils of the palaeozoic age, and sufficient other evidence to allow of his giving us a very accurate though general idea of the formation of the Amazonian Valley. His results were strongly opposed to the theory of Prof. Agassiz, of its glacial origin. He returned again to the Amazonas in 1871 with Mr. O. A. Derby. Together they carefully re- explored the same regions gone over before, adding mu:h to the stores already brought to the United States, and also examining the ancient Indian mounds and shell-heaps of numerous localities. Returning from Brazil once more he remained at Cornell University about three years, quietly working up the results of his later trips, and pubhshing his reports upon them. In August of 1874, by request of the Bra- zilian Minister of Agriculture, he went to Rio de Janeiro to submit his plans for the organisation of a Geological Commission of Brazil. He entered on his work in May, 1875, with five or six assistants. On the reorganisation of the National Museum at Rio, in 1876, Hartt became Director of its Department of Geology, but on account of his many other duties he was soon obliged to resign that position. The results of his researches may be briefly summed up as follows: — Be- fore he went to Brazil on his second trip, in 1867, scarcely anything Avas known of fossjHferous deposits there, and thus no material existed toward the study of the systematic geology of the country. A few cre- taceous fossils had been recorded from Bahia; the Danish naturalist Lund had very fully described the bone- caverns of Lagoa Santa in Minas Geraes, and we knew of -coal-plants from Rio Grande do Sul, but beyond this the palaeontology of Brazil was a perfect blank. Hartt's greatest achievement in Brazil was probably his solution of the structure of the Amazonian Valley. It was founded on the best of palaeontological evidence which proves the existence of an immense palaeozoic basin lying between the metamorphic plateau of Guiana on the north, and that of Central Brazil on the south, and through which flows the river Amazonas. Silurian, De- vonian, and carboniferous rocks, make up the series in regular succession, and in many localities are highly fossiliferous. He has explained the character of the isolated cretaceous deposits, mostly discovered by him- self, existing along the coast from Para to Bahia, and of the carboniferous and other regions south of Rio. He has shown us the manner in which the rocky structure of Brazil was built up, and has done much toward solving the relations of the crystalline rocks which compose by far the larger portion of its surface. He has explored the shell-heaps, burial-mounds, and other relic-locahties of the prehistoric tribes from far up the Amazonas to the southernmost coast province. We owe to him also the first real satisfactory explanation of the reefs of Brazil, which he distinctly shows to be of two kinds — sandstone and coral. He spent much time in studying the customs and languages of the modern Indian tribes of the Ama- zonas and Bahia, and collected very much material toward a grammar and dictionary of the Tupe Indian language m several of its dialects. But to attempt a complete account of Prof. Hartt's Brazilian explorations and dis- coveries Avould require a longer article than we can give here. In connection with the Geological Commission of Brazil he founded a large museum in Rio de Janeiro, which will always bear testimony to his great final under- taking. It forms the most complete repository of South American geology in the world. A start had just been made toward publishing the reports of the commission when the death of Prof. Hartt deprived it of its main support. But though this will occasion some delay in the publication, it is to be hoped that we shall soon have before us the entire results of this most important of explorations. Prof. Hartt's published works are not very voluminous. He was so confident of a longer life that he delayed too long, but still he was a constant contributor to American scientific periodicals. THE DARK CONTINENT^ T N our article last week on "Old Maps of Africa" we ■*■ said that even if it were the case that the great lakes and rivers of Central Africa were known to early Portu- guese missionaries and traders, it would not in the least detract from the glory of modern African explorers. Even if the work of those early travellers had not been clean forgotten, it was done so imperfectly that in any case it would have had to be done over again ; their work bears about the same relation to that of modern explorers that the observations of an ancient Chaldean shepherd watch- ing with powerless eyes the march of the stars, while he tended his flock on the hill-side, do to those of a modem astronomer armed with all the instruments of an observa- tory. It scarcely needs a perusal of these two volumes to convince us that it would be simply absurd to attempt to deprive Mr. Stanley of the glory of being the first white man whose keel has cleaved the broad bosom of the Upper Congo. He has done his work in such a May that there is no chance of it being ever forgotten. Let us at once assure those of our readers who may cherish the idea that, after having read Mr. Stanley's letters in the Telegraph, they need not trouble themselves with his book, that they labour under a delusion ; com- pared with the book, the letters are a mere prospectus, and therefore we cannot hope within the limits of an article to give any adequate idea of its contents. From a merely literary stand-point, Mr. Stanley's work deserves to take a high rank. We know no other narrative of travel with which it can be compared ; it reads more like a prose epic than a story of stern facts, and the reader who remembers his classics will be over and over again reminded of the story of the wanderings of Ulysses' as chanted by Homer. No such revelation of African life and African character and African scenery has ever been made, scarcely, we think, even in the half-fictitious pages of Winwood Reade. The trustworthiness of Mr. Stanley's narrative cannot for a moment be doubted ; his art has been evidently used simply to enable us to realise with perfect clearness the scenes and events through which he and his followers passed. From the numerous notices" we have published, our readers must be familiar with the great outlines of Mr. Stanley's discoveries. The two volumes before us are concerned mainly with the incidents of the wanderings of himself and followers from Bagamoyo to the mouth of the Congo ; another volume, which is promised for autumn, M'ill contain chapters on the hydrography, ethnology, and natural history of Central Africa, with " considerations " on the lakes, lands, and peoples of the equatorial regions ; as well as chapters on the hydro- graphy and physical geography of the western half of « '' Through the Dark Continent, or the Sources of the Nile, around the Great Lakes oi Equatorial Africa, and down the Livingstone River to the Atlantic Ocean." By Henry M. Stanley. Two vols. Maps and Illustra. tions. (London : Sampson Low and Co., 1878 ) 176 NATURE {Jtme 13, 1878 Africa, with special reference to the Livingstone Basin and River, and the volcanic formation of the defile through which the Livingstone falls into the Atlantic. Until the publication of this third volume it would be premature to discuss in detail the scientific results of the expedition, and we shall therefore at present content ourselves with briefly resuming the general results of Mr, Stanley's work. Mr. Stanley left Bagamoyo on November 17, 1874, with a force of porters, soldiers, and boatmen of about 350. The expedition was thoroughly equipped for its work, and it is evident that the best possible use was made by Mr. Stanley of all his advantages. The objects of the expedition were not rigidly defined, and generally they may be said to have been to clear up the many unsolved problems relating to the sources of the Nile, the great Scene on Lake Tanganika. lakes of Central Africa, and the course of the great river, which, coming from the far south, passed Nyangwd, and flowed then no man knew whither. The ultimate source of the Nile was unknown; the configuration of the Victoria Nyanza was so uncertain, and so many objec- tions had been raised to Speke's work there, that, as Mr. Stanley says, there was some danger of its being swept off the map entirely ; so defective was our knowledge of the lake, that some geographers, including the sagacious Livingstone, maintained that it was not one lake but many ; there was much to clear up in the region between Victoria and Albert Nyanza, and our knowledge of the latter was of the scantiest. The great western affluent of Lake Victoria, the Kitangul^, had to be traced, and our knowledge of Lakes Windermere and Akanyaru extended, as well as of the stretch bet^yeen the latter and Tanganika. June 13, 1878] NATURE 177 On the last-named lake, notwithstanding the labours of Burton and Speke, Livingstone, and Stanley himself, and even of Cameron, there was not a little to do to complete our knowledge. Then there was much room for additional work in the interesting country lying between Tanganika and the Lualaba at Nyangwe, where Livingstone has left an everlasting memory as "the good old white man." Last of all there was the mile-wide Lualaba itself sweeping past Nyangwd, "north, north, north," into the great unknown, perhaps to the Nile, perhaps to some great lake, perhaps bending west to the Atlantic ; though there could be little reasonable doubt that if a boat could run the gauntlet of the natives, it would find itself ultimately on the estuary of the Congo. These were the geographical problems to be solved, and Mr. Stanley solved them, and he only took two years and a half to do it. Until he reached Ugogo, nearly half way between Bagamoyo and Lake Tanganika, Mr. Stanley kept not far from the caravan route westwards, well known to all readers of recent African travel. Turning suddenly northwards, he made straight for the Victoria Nyanza, over a rugged table-land, interspersed with plains, and with at least one wide desert, and many villages. In about 5^° S. lat. he came upon some tiny streams which he ultimately found to be the head waters of a river of something like 300 miles long, that runs into Lake Victoria as the Shimeeyu, and which is undoubtedly the furthest south source of the Nile. Camping at Kagehyi, on Speke Gulf, Mr. Stanley in his trim boat. Cataract on Lower Livingstone. the Lady Alice, circumnavigated the Victoria Nyanza, defining every creek and gulf, and proving it to be one great lake with an area of 21,500 square miles, an alti- tude of 4,168 feet, and with border-soundings of from 330 to 580 feet. The lake is bordered with islands all the way round, is much indented with creeks and bays, receives numerous tributaries from all sides, and its shores and many of its islands are thickly inhabited. Mr. Stanley next set himself to the task of doing for the Albert what he had done for the Victoria Nyanza, but in this he was baulked by the timidity of the escort furnished him by his warm friend Mtesa, King of Uganda, on the north of the latter lake. He was only able to stand on the precipitous shore of what he named Beatrice Gulf. From what he then saw, combined with the information gleaned at the court of King Rumanika, he has plotted on the map accompanying his work the vague outlines of a new lake, to which he attaches the name of Muta Nzig^, somewhat to the south of the Albert Nyanza. The latter he locates in accordance with the recent circumnavigation of Col. Mason, with the pro- viso that after all there may be a connection between the two. If Mr. Stanley has not yet solved this problem, he has at least opened up a very interesting one, which pos- sibly the Egyptian pioneers may unravel. Coming south to the coast of Ruminika, King of KaragAve, the gentle friend of Speke and Grant, and now of Stanley, he was able still further to add to our knowledge of a region teeming with interest, and again to open up problems which successive explorers must solve. We have now some idea of the great affluent of the Victoria Nyanza, Avhich, issuing from Lake Akanparu, flows north through a long series of swampy lakes before it turns east to feed the great reservoir of the Nile. About Lake Akanyaru itself we know but little. Mr. Stanley, in the maps which accompany his work, no longer makes a long river flow from the west to feed it, though a considerable stream comes south from the Ufumbiro Mountains. 178 NA TURE \ytme 13, 1878 Still, however, he gives it a connection Avith little Lake Rivu, the supposed source of the Rusizi, the northern affluent of Lake Tanganika. Here is another curious riddle awaiting solution. Coming to the Tanganika itself, we may say that Mr. Stanley has virtually completed our knowledge of its configuration, having for the first time defined the outline of its southern shore and proved that the Lukuga has not yet become an effluent, but promises ere many years to carry the waters of the lake to swell the volume of the Lualaba. Mr. Stanley adduces the strongest proofs that the Tanganika is rising with comparative rapidity, and it is possible that further research may show that the earliest Portuguese explorers, if ever they reached it, found two lakes on its site, divided by a ridge nearly half- way between its north and south points. Mr. Stanley, before he began his work of exploration, evidently used great diligence to qualify himself as an observer in geology and natural history. That he is a keen observer his work shows, and it is evident he has collected a mass of data in geology and natural history, as well as in ethnology, which will prove of the greatest interest to men of science, and which we may look for in the pro- mised third volume. Evidently the geological conditions of the bed and shores of the Tanganika, as well as of the -whole basin of the Livingstone, are unusually interesting and have occupied much of the explorer's attention. Until we have the whole of the data it would be pre- mature to theorise. The lake Mr. Stanley makes out to be 329 miles long, with an area of 9,240 square miles. With 1,280 feet of cord he could find no bottom. Yet though the Tanganika is rising, Mr. Stanley seems to be of opinion that at one period nearly the whole of :he great area drained by the Livingstone was under water, and that the numerous lakes to the west and south-west of Tanganika, with the river itself, are all that now remain of the great inland sea, if inland it was. On the banks of the Tanganika itself, high above the lake-level, he found rocks bearing distinct evidence of having been worn and rounded by water. Here is a splendid field for the ■enterprising geologist. Of the great river itself, what more can we say but that, in the face of the most stupendous difficulties, he traced its course from Nyangwe to the sea ? It is a splendid epic, this narrative of the expedition down this great river, whose banks are lined with the villages of hostile and cannibalistic natives, who literally hunted the Jittle band for hundreds of miles. We doubt much if another man could be found who could have carried such an enterprise through with success. Anyone but Stanley would either have turned or been eaten ere the first cataracts were reached. One village street was fringed on each side with rows of skulls, which he was told were those of the soko — probably a species of chimpanzee. One of these, brought home by Mr. Stanley, was sub- Tnitted to Prof. Huxley, who has diagnosed it as that of a human being. Of the dimensions of this river we have already spoken, and of its basin, of nearly a million square miles. Its discovery was worth all the sacrifices that were made ; and, unless we are to count the pursuit of knowledge as an object of no worth, it must be ad- mitted that Mr. Stanley has here done a thing that entitles him to rank in the first order of the pioneers of science. Apart from its high value as an addition to geographical knowledge, its importance as a highway to new fields of commercial enterprise cannot be overrated. North and south of it yet there are great white spaces to be filled ^ip, but with such a magnificent base-line that should not be difficult to do. Such is a brief outline of the principal geographical -discoveries made by Mr. Stanley; but it gives the very faintest idea of what the reader will find in his book. Africa and African, to those who study these volumes, will be no longer mere names : the genius of Mr. Stanley has infused into them the breath of life. Mr. Stanley's strong human sympathy, aided by his knowledge of the Kiswaheli, has enabled him to bring before us the natives of Central Africa with a dramatic vividness never before attained. Henceforth it will be inexcusable to lump together the Waswaheli, the Wagoro, the Waganda, the Wanyamwesi, the Wajiji, the people of Manyema, and the many other tribes that people this much-watered land, as mere uniformly characterless "niggers." In Mr. Stanley's pages we see these various states and many individuals, each Avith their distinctive characteristics. The physique of the various peoples, their manners, their houses, utensils, and weapons, their dress, their modes of Ufe, and even their modes of thinking and speaking, their legends, are pictured for us by pen and camera and pencil in a manner that must impress the laziest reader. The ethnologists will be able to glean many facts and hints here, and still more we should think from the Kitete, Chief of Mpungu, near the Lualaba. volume that is to follow. Mr. Stanley presents us with a remarkable legend from Uganda, the Kingdom of Mtesa, concerning a blameless priest named Kintu and his descendants, which is well worth the study of the comparative mythologist. We have another strange legend as to the origin of the Tanganika, and we should think that in his wanderings much material of a similar kind must have been collected by Mr. Stanley : if so he would do science a service by publishing it. The chapters devoted to Mtesa and his kingdom are of special interest, and the explorer's friendship with this remarkable potentate promises to be fruitful of results. Further interesting details are given as of the mysterious white people of Mt. Gambaragara on the east shore of Muta Nzige, which must rouse the curiosity of ethnolo- gists. We learn a good deal also about the wandering Watuta, the terror of Central Africa, and of King Mirambo, a sort of African Napoleon, whom, however, Mr. Stanley speaks of in high terms as superior both in character and intellect to the general run of African "kings." Much new information also have we on the JuTie 13, 1878] NATURE 179 inhabitants of the Tanganika shores and the artistic people of Manyema, with their elaborately coiffeured heads. To speak of these people, and even many of the tribes on the banks of the Livingstone, as savages is a misuse of language. People who can build houses and organize villages and towns such as they do, who can work their native iron, ivory, wood, and bone, into all sorts of artistic and useful shapes, and who can reason and speak as Mr. Stanley shows us they do, have raised them- selves to a level considerably higher than the savage. West of Tanganika, especially, the tribes seem very much mixed up, and there are many evidences that the Living- stone with the neighbouring region is a sort of border- land where several races meet, and where a constant struggle is going on. What can be made of these Africans under competent direction, Mr. Stanley himself has shown us in the case of his own people. Of the various products, mineral, vegetable, and animal, of the country through which Mr. Stanley passed we have many glimpses. The natural wealth of the country is extravagant, and the botanist especially will find much that will interest him, especially as Mr. Stanley has been at the trouble of frequently giving the scientific names of the plants which he mentions. There is ample furniture of maps in the work, all of them well-executed, though in Mr. Waller's two large maps there are occasional signs of carelessness in the spelling of names, and, very strangely, the memorable Vacovia of Sir Samuel Baker is omitted from the names on the east shore of Albert Nyanza. Beside the two large maps of East and West Equatorial Africa, by Mr. Waller, there are also an interesting series of five maps by the same hand, showing the progress of discovery in Equatorial Africa. There is, first, a portion of Dapper's map of 1676, very similar to that of 1701, which we gave last week, showing two great central lakes, from the most westerly of which, Zaire lacus, issue both the Nile and Congo. The next one shows our knowledge between 1849-56, with all the features of Dapper's maps swept away, and the first rude indication of Tanganika given. Then, between 1856-63, we have the work of Livingstone, Burton, Speke, Grant, enabling us to more correctly define Tanganika, locate Victoria Nyanza, and shadow out Albert Nyanza. The next stage, 1866-75, shows a great advance. By the labours of Schweinfurth, Baker, Livingstone, Stanley (first journey), and Cameron, the main features, from 10° N. to 15" S., east of 25° E. long. — rivers, lakes, and mountains— are filled in more or less accurately. Last of all come the results of the journey described in these two volumes, and which we have endeavoured to summarise in this notice. There is also a chart of the Lukuga creek, and two beautiful large-scale charts, by Stanford, of the Livingstone or lower falls (thirty-two in number), and of the upper or Stanley falls. Mr. Cooper has, as usual, done his part well in repro- ducing the numerous and varied illusti-ations ; and alto- gether the get-up is thoroughly creditable to the publisher. In conclusion, let us repeat that Mr. Stanley has done a great work, and told us all about it in a great book. OUR ASTRONOMICAL COLUMN The Transit OF Mercury, 1868, November 4.— The second internal contact at this transit was well observed in many European observatories, though at others the bad definition and tremulousness of the sun's limb vitiated the results. If we calculate strictly from Le- verrier's tables of sun and planet, with Prof. Newcomb's value of the mean solar parallax, 8"-848, we shall have the following formula for reduction of the observed Greenwich mean time at any place to the centre of the earth : — /^ = 2oh. 5901.51-95. -F [1-4056] r sin / - [i-7232]/-cos/, ccs(Z. -(- 55° si'-s). where / is the geocentric latitude, r the radius of earth at the place, and L the east longitude from Green- wich. A comparison with observations shows difierences as below : — Observed Place of G.M.T. Error of the Observation. reduced to Calculatioa. earth's centre, h. m. s. Bonn 21 o 3*4 - 11-5 Three observers : extreiaes. differ, 13-55. Christiania — 6*3 — 14*4 " Four observers Durham — 12*2 — 20*3 Greenwich — 6'9 — 15*0 Six observers. Leyton — 12*6 — 20*7 Lund — 14*4 — 22-5 Madrid — I3'8 — 21*9 Merino. Rupture of ring. Marseilles 20 59 57-6 — 5*7 Leverrier. „ 21 o 12-6 — 207 Stephan. Paris - 7-6 " ^ 57 j'^rnd Wotff!^"^'' '''"'"""'' .. 20 59 57-0 - 5-1 Rayet. Rome 21 o 10*4 — 18*5 Secchi and Mancini. Vienna 20 59 55*5 — 3-6 Oppolzer. .At the Royal Observatory, Cape of Good Hope, where the transit was very completely observed, the sun' s limb, is stated to have been tremulous at the second internal contact, which probably accounts for the larger differ- ence, -32'2s., between calculation and observation, Brorsen's Comet of Short Period. — When the elements of this comet, at its first appearance in 1846^ had been satisfactorily determined, it was pointed out by Mr. Hind, in a communication to the Royal Astronomi- cal Society, that the comet must have made a very close approach to the planet Jupiter about May 20, 1842, and that probably to this near approximation the form of the orbit in 1846 might be attributed. The late Prof. D' Arrest examined this question more closely in the year 1857, and by the formulae of the Mecaniqiie Celeste^. which had been already applied in the case of Lexell' s- comet of 1770, he ascertained that a great change of elements was then caused by the action of Jupiter^ assuming the mean motion given by the observations of 1846 to be affected with no material error, as we now know to have been the case. He found that the greatest proximity occurred May 20'69, Berlin time, when the distance of the comet from Jupiter was only o"o5ii of the earth's mean distance from the sun, and that previous to April 19, 1842, the elements of the comet's orbit were as follows. The elements of 1 846 are added for com- parison : — Elements before the Elements ia great perturbation. 1846. Mean longitude, 1842, April 19*5... 23716 ... " — Longitude of perihelion 133 27 ... Il6 2S ,, ascending node ... 107 44 ... 102 40 Inclination to ecliptic 40 51 ••• 3° 57 Eccentricity o*59275 ••• o'793S6 Semi-axis major 3*68645 ... 3'i5352 These figures prior to 1842 are necessarily only a first approximation to the orbit then described, but they suf- ficiently explain the circumstance of the comet not having been observed before that year, since the perihelion dis- tance was then greater than 1*5, and as Prof. D' Arrest remarked, under this condition Brorsen's comet would hardly be observable. According to Dr. Schulz's elements for 1873, when the. comet was last visible, the nearest approach of its orbit to that of Jupiter now takes place in 283° 30', when the distance is o'i24, and thirteen revolutions of the comet are almost exactly equal to six revolutions of Jupiter. D' Arrest, from a rough calculation, considered that thei orbit might again undergo great or complete change frora the action of this planet in the year 1937. The only i8o NATURE {JiLne 13, 1878 other planet which the comet can approach with its actual elements is Venus, which, near the ascending node, may be within o'li. MiRA Ceti. — According to Schonfeld's calculation the next miiiimnm of this variable will occur on June 23. and the next maximum on October 11. There are com- paratively few observations of the former phase and more attention to it is desirable. At present it is assumed that the perturbations of the maximum deduced from Arge- lander's formula, apply also to the nearest minimum. In this case the sum of the perturbations is +.29"9 days. GEOGRAPHICAL NOTES We last week referred to the important work done by Sir Andrew Scott Waugh in connection with the Great Trigonometrical Survey of India, and from the recently issued Report of Colonel Walker, the present Superinten- dent of the Survey, it will be seen that the work is being carried on with unabated energy. The Report refers to 1876-77, and tells us that during that year an area of 5,019 square miles was covered by principal triangulation; under secondary triangulation 5,400 square miles have been covered with points for the topographical survey, 3,100 miles have been operated \vi pari passu with the principal triangulation, and in an area of 23,600 square miles, lying mostly in portions of the Himalayas which are inaccessible to Europeans, a number of points have been fixed which will be valuable for geographical rectifications. The topography of upwards of 5,000 square miles has been completed in scales varying from half an inch to two inches, while several important geodetic operations were accom- plished. In these Reports there is generally some important geographical work to record, accomplished by one of the native officials of the Survey. During the year 1876, the Mullah, one of the purvey explorers, made a survey up the course of the Indus from the point where it enters the plains above Attok, to the point where it is joined by the river of Gilghit. This is the only portion of the Indus which had remained unexplored. Here the river traverses a distance of some 220 miles, descending from a height of about 5,000 feet to that of 1,200 feet above sea-level. Its way winds tortuously through great mountain ranges, whose peaks are rarely less than 15,000 feet in height, and culminate in the Nanga Parbat, the well-known mountain, Avhose height, 26,620 feet, is only exceeded by a very few of the great peaks of the Himalayas. The river in many places is hemmed in so closely by these great ranges that its valley is but a deep-cut, narrow gorge, and, as a rule, there is more of open space and culturable land in the lateral valleys, nestling between the spurs of the sur- rounding ranges, than in the principal valley itself. No European has ever penetrated this region, and the Mullah only managed it by travelling as a privileged trader. Very difficult of access from all quarters, it is inhabited by a number of hill tribes, independent and suspicious of each other, and protected from each other by natural barriers and fastnesses. Each community elects its own rulers, and has little intercourse with its neighbours, and with the outer world only by means of privileged traders. The captain of a German steamer, just arrived at Hong- kong, reports a singular condition of things in the island of New Britain, in the South Seas. He found the whole of the north-east coast enveloped in dense smoke, and he experienced great difficulty in proceeding up the channel between it and New Ireland, as fields of pumice-stone, several feet in thickness, covered the surface of the water. On Febniary 9 he reached Makada, Du'^e of York group, and found that three craters had broken out in the New Britain peninsula, at the foot of the so- called Mother and Daughters Mountains, from which dense masses of pumice-stone were continually being thrown up. The passage between Duke of York Island and Blanche Bay had been completely closed by a com- pact field of pumice-stone, about five feet in thickness, according to the statement of the captain to a Hongkong paper. A tidal wave swept over Blanche Bay on February 10, and soon afterwards a new island appeared, about three-quarters of a mile in diameter. This island is situated to the south of Natopi, or Henderson Island, and where it now is no bottom was previously obtained at seventeen fathoms. It is probable that other altera- tions have taken place which could not be observed at the time, owing to the masses of floating pumice-stone. The captain of the vessel mentioned further states that the water in Blanche Bay was scalding hot for two days, and that immense quantities of boiled fish and turtle were thrown on shore, and eagerly devoured by the natives, who were starving in consequence of the unusual dryness of the season. The party which left England last month for Egypt on their way to reinforce the Church Missionary Society's ex- pedition to the Victoria Nyanza, will proceed by steamer to Suakim, the port of Southern Egypt, accompanied pro- bably by a dragoman engaged by the British Consulate at Cairo. At Suakim it is proposed that they shall engage camels to transport them across the desert to Berber, on the Nile, whence they will travel by steamer to Khartum. From that point they will journey under Col, Gordon's protection, and will, doubtless, have no difficulty in reach- ing Gondokoro. Thence it is arranged that they shall proceed by the Egyptian military outposts to the frontiers of Uganda, in which country Col. Gordon now has an agent, whose presence will no doubt insure safety to Europeans. A letter from the French Ogowd Expedition was read at the last meeting of the Geographical Society of Paris. It is quite a year since it was written, and some appre- hensions have been entertained as to the safety of the explorers. M. de Brazza states that the Ogowd is reduced to small proportions and flows from the south, so that it gives the impression of being really an arm detached from the Congo. The expedition was to travel north- wards in order to examine the sources of a powerful affluent. Illness was prevailing amongst the small party, and the hostility of the native tribes was growing stronger. The forthcoming congress of the Geographical Society of Paris will not be international, but national, although it will be open to foreigners. The principal aim of the congress will be to organise a federation, between the Paris Society and similar institutions which its influence has started in large provincial cities during the past five years — viz., Lyons, Bordeaux, Marseilles, and Montpelier, where a society for the whole of Languedoc was recently established. A Reuter's telegram states that the schooner Eothen will probably sail from New York on Monday next for the Arctic regions to search for relics of the Franklin expedi- tion. No doubt the purpose of this expedition is to obtain the relics reported to be in the possession of some of the mainland Eskimo. A meeting of the subscribers to the African Explora- tion Fund of the Royal Geographical Society will be held in the theatre of London University at 3 P.M. on Friday, June 14. Sir Rutherford Alcock, K.C.B., Chairman of the Committee, will preside. ON A NEW METHOD FOR DISCO VERING AND MEASURING MOLOTROPY OF ELECTRIC RESISTANCE PRODUCED BY ALOLOTROPIC STRESS IN A SOLID 1 'T^ORSION of a metal tube within its hmits of elasticity -*■ produces ccolotropic stress, of which the mutually perpendicular lines of maximum extension and maximum ' Abstract of a Paper read by Sir \V. Thomson at the Physical Society, May 25. junt 13, 1878] NATURE i«i contraction are spirals, each very nearly at 45° to the length of the tube. From the author's early experiments (described in his paper on Electrodynamic Qualities of Metals, published in the Transactions of the Royal Society for 1856), showing a diminution of electric conductivity by puUing force in metallic wires, and Mr. Tomlinson' s recent con- firmations and extensions of those results, it is to be ex- pected that the conductivity of the substance will be less in the direction of extension and greater in the direction of contraction in the stressed substance than the con- ductivity (equal in all directions) of the substance when free from stress. Hence, if an electric current be main- tained along a tube, torsion would cause it to flow in spiral stream-lines, with spirality of opposite name to that of the twist. The whole flow may be resolved into two components : one right along the tube, the other round it. The latter would (like the current through a galvanometer-coil) deflect a needle hung in the interior of the tube with its axis perpendicular to the tube when undisturbed. Or it would magnetise a bar or wire of soft iron placed within the tube. The current itself would (except near the end of the tube) produce no ex- ternal effect directly ; but either of those appliances may be used to give an external indication. Since the last meeting of the Physical Society, when the author raised this question of the spiral electric stream lines in a twisted tube, experiments have been made for him by Mr. Macfarlane in the physical laboratory of the University of Glasgow, on the last-mentioned plan; and on the former plan by Mr. J. T. Bottomley in the physical laboratory of King's College, London, by kind permission of Prof. Adams, and with the valuable assistance of his staff. Mr. Macfarlane, using a small mirror magnetometer suspended externally in the neigh- bourhood of one end of an iron wire placed within a brass tube, found that when the twist of the substance was right-handed the end of the wire next that end of the tube by which the current enters becomes a true north pole. Mr. Bottomley, with the cell and suspended mirror and needle of an ordinary dead-beat mirror galvanometer supported by an independent support within a brass tube along which a current is maintained, found that the true north pole of the needle is moved towards the end of the tube by which the current enters. Thus both Mr. Mac- farlane's and Mr. Bottomley' s observations confirm the anticipation that the electric conductivity is least in the direction of greatest extension, and greatest in the direction of greatest contraction of the metal. The apparatus by which Mr. Bottomley had made his experi- ment was exhibited to the meeting. It included a mode of balancing the effect on the internal needle by placing a circular portion of the main circuit at a proper distance from it, the centre and plane of the circle being in and perpendicular to the axis of the tube. From a measure- ment of the distance from the centre of the circle to the needle, when the balance is obtained, the ratio of the maximum to the minimum conductivity can be cal- culated. NOTES . We publish a remarkable paper this week, by Mr. J. BIyth, on a new form of the microphone, which needs neither battery nor telephone. The curious importance of Mr. Blyth's inven- tion need not be insisted on. By backing-up the pictures in a drawing-room it might, as has been suggested by a learned professor, be converted into an Ear of Donysiu?, and Horace's words, "suppositos cineri dolose," would come to have an .awful meaning. ' At the Royal Society on Thursday last, all those proposed as new Fellows, and whose names we have already published, were unanimously elected. Prof. Simon Newcomb has published as a Supplement to the " American Ephemeris and Nautical Almanac," a few instructions for the observation of the total eclipse of the sun on July 29. The instructions refer to the limits of path of the shadow, instalments, arrangements for observation, the actual observation, search for intra -mercurial planets, drawings of the corona, &c. Prof. Newcomb's paper is accompanied by a series of photolithographic maps of the part of the United States concerned. They include a region extended about 150 miles on each side of the limits of totality. These maps contain certain special features which will render them very useful to observers. For example, on the right-hand side of the track is found, at convenient intervals, the Washington mean time at which the centre of the total phase reaches the several points, where the times are marked. From each of these points a dotted line extends across the path of totality ; this Une is the projection of a diameter of the shadow at the time indicated, so that the middle of the total phase occurs at this time all along the dotted line. These, and other featiures, render these maps of special utility, A LETTER has been received in London by Dr. George Bennett, of Sydney, from Signor L. M. D'Albertis, the New Guinea traveller, dated fi"om Sydney, New South Wales, April 14, 1878, in which he says, "I have taken my passage in the Caroline, which leaves direct for London on the 1st of May next, and expect to arrive in London about Jmie 15, when I hope to see you. It is my intention to bring all my ethnological and other collections of natural history with me." A LABORATORY for the study of marine zoology, in connec- tion with the biological department of the Johns Hopkins Uni- versity, will be organised this summer at Fort Wool, about a mile from Old Point Comfort, Va. The fort contains commo- dious buildings for laboratories and dormitories. The necessary apparatus for collecting and studying marine animals, nets, dredges, microscopes, reagents, aquaria, tables, &c., as well as a small scientific library, will be provided by the University. Through the kindness of the Maryland Commissioner of Fish and Fisheries, the boats used by the Commission will be at the service of the laboratory. The laboratory is organised mainly with a view to the wants of advanced scientific investigators, and there will be no formal courses of lectures. There will, how- ever, be accommodation for a few less advanced students, and suitable instmction will be furnished to meet their individual needs. Botanists will be gratified to learn that the publication by Prof. Asa Gray of his great work upon the "Flora of North America " has been commenced, and will be continued as rapidly as practicable. Many years ago a work with the same tide was started by Drs. Torrey and Gray and carried through the Com- positze, where it stopped. The vast extension of the field of American botany, consequent upon the discoveries in California, Oregon, and other regions west of the Mississippi, has made the want of a manual extremely imperative, and this will be furnished by the work referred to. For the purpose of better satisfying the wants of students the work begins with the Gamopetalse irmnediately following the Compositse, and the ground covered by the original " Flora " will be taken up after the other orders are completed. The entire work will consist of two volumes of about 1,200 pages each, the first part, now issued, embracing about 400 pages. The book is to be had from the curator of the Harvard Herbarium at Cambridge. The Japanese Government, which is making such rapid strides towards modern civilisation, has just awakened to the necessity of preserving its forests, and stringent regulations have been passed, which shall not only hinder the too rapid destnic- tion of the forests, but increase the area covered by woodlands. l82 NATURE \7une 13, 1878 A VERY interesting paper was recently read before the' Asiatic Society of Japan, by a native of that empire, in which the records of the earthquakes in that insular region for the past fifteen centuries were carefully compiled and classified. It appears that since the year 406 A.D. the authorities of Yeddo and other large cities have preserved, almost without interruption to the present time, descriptions of all earthquakes occurring, with their accompanying phenomena. As a rule it has been observed that the great shocks were preceded by a rise of tem- perature and violent atmospheric perturbations. The general average of great earthquakes has been ten in the century. The average of the present century is, however, double that number, and in the ninth century there were no less than twenty-eight destnictive earthquakes. The litt referred to describes a total of 150 great earthquakes during the past fifteen centuries, and a host of minor shocks. It is certainly one of the most novel and valuable contributions to this department of meteorology, and it is to be hoped that it will appear in a form and language avail- able for European savants. The Japanese Government are evidently also losing no time in extending their system of telegraphic conununication, for we learn from a Japan contemporary that there are now 125 tele- graph stations in the country, and it is estimated that there are 5,000 miles of wire in operatisn ; 1,000 miles more are in course of construction, and still further extensions are contemplated. Considering that the first telegraph line for practical purposes was not erected in Japan before the end of 1869, the result achieved is by no means unsatisfactory. We have before us three small publications, which indicate the activity of scientific research, especially botanical, in the United States. 1. The Botanical Directory of America for 1878 shows an array of names which would compare favour- ably with the number that could be included in such a list in the old country. Even those who are aware how much good work has been done by American women in several branches of science would hardly be prepared to find so large a proportion of ladies as are to be seen in the present list. 2. Jahresbericht des naturhistorischen Vereins von Wisconsin fiir das Jahr 1877-78, is a record of the year's work of the Natural History Society for the remote State of Wisconsin, so largely settled by Germans. Though some of the papers are in English — includ- ing an interesting one by Dr. E. N. Bartlett on Aspergillus, detected by him as a parasite in the ear, causing partial deaf- ness— the official language of the Society appears to be German. 3. "A Catalogue of the Flowering Plants and Higher Crypto- gams growing within thirty miles of Yale College," published by the Berzelius Society, appears to be carefully executed. The total number of indigenous species is— 1,037 flowering plants, 52 vascular cryptogams, and 221 Muscnije, besides 196 intro- duced flowering plants. It is accompanied by a map. " Vis Medicatrix Nature." In the light of this venerable saw we do not think it inappropriate in these pages to support an appeal which Dr. Dawson W. Turner asks us to make on behalf of the thousands of patients in the hospitals in and around London. The true healing art is based on rigid scientific research, and one of the most effectual methods of assisting the physician's efforts is to keep the patient in a cheerful mood and divest his thoughts fi-om himself and his aflliction?. A potent means to this end is cheerful reading, and we are sure that in this direction many of our readers will be able to assist Dr. Turner in his beneficent mission. Mr. Turner finds that of this class of books none are so acceptable to the sick and suffering, who can read, as the cheap one-volume editions of the best of our standard novelists — Scott, Dickens, and Marryat, especially, and then Trollope, Miss Sewell, Mrs. Gatty, and a host of others. Dr. Turner rightly makes a point of excluding everything that '.s the least "senEaliona]." The liijhter sort of serials are also acceptable, such as Good Words, Aunt Judys Magazine, Leisure Hour, and so forth, as well as picture- and scrap-books, espe- cially if the leaves are pasted on linen. We would add that we are sure many of the patients would welcome some of our more popularly written illustrated scientific works, which tell of greater wonders than ever novelist imagined, and the reading- of which, besides amusing the patients, would leave a solid residue of knowledge behind. Dr. Turner's address is 13^ Salisbury Street, Strand, W.C. In the forthcoming/^/^ to be given by the City of Paris, no less than 200 electric candles will be kept burning during the whole of the night in several parts of the city, besides the regular display, which has been increased since our last note. Some of our readers may remember that Leverrier proposed to the French government to extend weather-warnings not only to agriculturists but also to the men who risk their lives in collieries. The mournful accident which has occurred near Wigan recently adds force to Leverrier's proposal, and surely, on the chance of its preventing such accidents, the plan might be tried. In Lisbon and its vicinity there was a violent shock of earth- quake, accompanied by a storm of wind, at eleven o'clock oa Saturday night, the duration about six seconds, and the direc- tion east to west. Much alarm was caused. The Societe Frangaise d'Hygiene Publique, has appointed a. Commission for utilising the Giffard Captive Balloon in the study of questions connected with hygiene, such as the influence of rapid decrease of pressure on vital functions, the causes of vertigo, &c. A preliminary programme has been published already. The Congress of Hygiene appointed by the French Ministry for the occasion of the Exhibition, will take place at the Trocadero Palace in tlie month of August. A number of excursions of special interest will be organised on the occasion. The initiative committee meets every week on Wednesday at the Pavilion de Flore (Palais des Tuileries), in the room where the late Congress of Geography was recently held. Prof. Peligot of Paris discusses, in a recent number of the Ann. de Ch. et Phy., the composition of ancient glass, com- bining his own analysis with a careful study of all passages o» the subject in ancient authors. The specimens which he exa- mined all contained mixtures of soda and potash, with but minimal quantities of life — one-third to one -half of the amount used at present. Prof. Peligot comes to the conclusion that flint-glass was entirely unknown in ancient times. From the recent report of the secretary of the Societe Chi- mique de Paris, we notice that its membership is at present 383, consisting of 140 members dwelling in Paris, and 243 non-resi- dent. The yearly receipts amount to over 15,000 francs, of which a third is saved for investment. The Society possesses now a capital of 44,000 francs. Its bi-monthly Bulletin forms a yearly volume of 1,200 pages, and has a circulation of oves 400 outside of the Society. We i-ecently drew attention to Winkler's remarkable lunar landscape, now being exhibited in London. Something eveii more extensive, if not, perhaps, quite so artistic, is to be attempted by an American artist, if he can procure a sufficient number of subscribers. Mr. Henry Harrison, of Jersey City, has already painted a picture of the moon three and a half days old, and although we have not seen it ourselves, it is so highly spoken of by Dr. H. Draper and Mr. Rutherfurd, that we do. not hesitate calling our readers' attention to the artist's proposed publication. The picture represents the moon with the termi- nator at Mount Glacier, showing the earthshine on the surface in shadow in which some of the most prominent features, i.e., the cra- ters Copernicus and Tycho, the Appenniiie Mountains, and nearly June 13, 1878] NATURE ^^3 all the." meres" are visible. Having submitted the work, Mr. Harrison tells us, to gentlemen of scientific repute, and being encouraged by their favourable criticisms, he has concluded, if a sufficient number of subscriptions can be obtained, to publish a work under the title of " Telescopic pictures of the Moon," in oil colour chromos (the only medium for facsimile reproduction of paintings) 2 feet in size, with an image of 18 inches in dia- meter, in hix progressive pictures of the following phases : — I. Three days old crescent, terminator at Mount Glacier. 2. Five days old, terminator at the crater Katharina. 3. Seven days old, or first quarter. 4. Nine days old, sunrise at the crater Copernicus. 5. Full moon ; and 6. Last quarter. An outline drawing with letter-press description, bearing the names and sizes of all objects, will accompany the work, which will be com- pleted in about a year from the time the first phaie has been issued, and will be furnished to subscribers complete for 3odols., or 5 dols. for each plate. The description will appear gratui- tously with the last issue. Subscribers should send full name and address to Henry HaiTison, P.O. Box, 179, Jersey City, New Jersey. A VERY successful experiment has been made at Lockport, New York State, in supplying heat to houses by steam supplied from a central station, in much the same way as gas is supplied. The experimental works in Lockport were commenced last year, and during the late v.inter about 2CO houses in the city were heated from the central supply, through about three miles of piping, radiating from the boiler-house, containing two boilers 16 feet by 5 feet, and one boiler 8 feet by 8 feet. These boilers were, during the winter, fired to a pressure of 35 lb. to the inch, with a consumption of 4 tons of anthracite, costing 41 dols. a ton during the summer, but one boiler is fired consuming a ton and a half of anthracite in twenty-four hours, and a pressure of 25 lb. per inch maintained. The boiler pressure of 35 lb. in winter, and 25 lb. in summer, is maintained through the entire length of the three miles of. piping up to the points of consumption, where there is a cut-oiT under the control of the consumers. The distribution of heat in the apartments is by means of radiator.-, consisting of I inch pipes 30 inches long, placed vertically either in a circle or as a double row, and connected together, top and bottom, with an outlet pipe for the condensed water, which escapes at a temperature a little below boiling, and is sufficient for all the domestic purposes of the house, or is used as accessory heating power for horticultural and other purposes. The steam has also been applied at a distance of over half a mile from the boilers for motive power, and two steam-engines of ten and fourteen horse-power are worked from the boilers at a distance of half a mile, with but a slightly increased consumption of fuel. ITie laid on steam is being also used for cooking purposes, for boiling, and even baking, and -Mr. G. Maur, F.G.S., who describes the system, witnessed in a house three quarters of a mile from the boilers, a bucket ^ofxold water raised to boiler heat in three minutes by the passage of the steam through a perforated nozzle plunged in the bucket. The operations of the Heating Company have been up to the present time of an experimental character, and from the 200 houses already supplied ^^ ith the heating connection," the actual cost of the coal that would have been used for heating has been provisionally received in pay. ment, and the amount has left a wide margin over the working expenses, though the company's operations at present cover but a small portion of the area for which they have provided plant. The additions to the Zoological Society's Gardens durino- the past week include two Mandrills {Cyitocephalus mormon), an Ocellated Monitor {Monitor ocellatns) from West Africa, pre- sented by Mr. G. H. Garrett ; two Greater Spotted Woodpeckers {Pkus major), British Isle.-, presented by Mr. J. A. Cooper; a Greater Sulphur-crested Cockatoo {Cacatua gaUrita) from Aus- tralia, presented by Mr. N. Portocalis ; a Horned Lizard {PhrynosoTna cornutnni) from Texas, presented by Mr, J. C. Witte ; a Common Chameleon (C/iama:leon vulgaris) from North Africa, presented by Mr. W. W. Spicer ; two Indree Owls {Syrnittm indrattee) from Ceylon, deposited ; two Common Seals {Phoca vitulina) from British seas, a White-fronted Amazon ( Chrysotis leucocephala) from Cuba, two Oyster Catchers (Hcemaiojrus ostralegus), British Isles, purchased ; two Horned Tragopans {Cerior7tis saiyra), an Impeyan Pheasant {Lophophorus impeyanus), bred in the Gardens. THE ROYAL -OBSERVATORY 'T^HE annual visitation of the Royal Observatory took place ■*• on Saturday week, when the Astronomer-Royal read his Report, which refers to the year ending May Zt The Report on the buildings and grounds, movable property, manuscripts, library, astronomical instruments, &c., is, as usual, satisfactory. The new railway through the town of Greenwich has apparently had no effect at the observatory. The usual varied astronomical observations have been carried on with the usual diligence, the advantageous observation of the small planets being, however, limited by the want of ephemerides. To facilitate the observations of stars, a new working cata- logue has been prepared, in which are included all stars down to the third magnitude, stars down to the fifth magnitude which have not been observed in the last two catalogues, and a list of 258 stars of about the sixth magnitude of which the places are required for the United States Coast Survey. The whole num- ber of stars in the new working list is about 2,500. An exten- sive series of observations was made, during the autumn, of about seventy stars, at the request of Mr. Gill, for comparison with Mars, Ariadne, and Melpomene. Among the observations made we may mention 3,970 transits, the separate limbs being counted as separate observations, and 3,824 circle obsei'vations, each requiring a separate reading of the six microscope micrometers. Twenty-nine sketches of Mars were obtained with the great equatorial near his oppo- sition, forming a complete record of the appearances of that planet during the entire rotation. Preparations were made for observing the Transit of Mercury on May 6, but owing to the unfavourable state of the weather no result of importance was obtained. A great amount of work has been done in the reaction of astrononomical observations. The computations for the " Nine- Year Catalogue " of 2,263 stars, including some supplementary investigations, were com- pleted in the course of 1877, and the introduction has been prepared and sent to the printer. The catalogue is drawn up in the same form as previous catalogues, the only noteworthy alterations being the addition of another decimal place to the R.A.'s and annual precessions in R.A., which are carried to os"ooi and os'oooi respectively. The right ascensions are thus made to correspond more nearly with the north polar distances as regards the degree of accuracy exhibited. During the past year the sun's chromosphere has been exa- mined with the spectroscope on seventy-nine days (on two of these through part of the circumference only) ; prominences were seen on fifty- eight days. All the observations, however, tend to show that the solar prominences have been few in number and insignificant in size for many months. All observations with the spectroscope have been com- pletely reduced ; the position-angles of prominences being con- verted into heliographic N.P.D. ; and the displacements of l.nes in the spectra of stars being reduced so as to exhibit the concluded motion in miles per second, after applying a coitcc- tion for the earth's motion. The areas, position-angles, and distances from the sun's centre, of sun-spots and faculcc, have been measured to the end of 1877, and in duplicate July 5, 1877. The coiTCction of the position-angles and distances for the effects of refraction and distortion, and their conversion into heliographic longitude and latitude, have been pushed forw ard as rapidly as circumstances would admit after the measurements had been completed. As there is a considerable accumulation of arrears since 1873, which will require many months for their reduction, it has seemed desirable to commence with the year 1876, with the view of including in the volume for 1876 the 1 84 NA TURE [June 13, 1878 complete deductions from the measui-es of sun-spots and facultc in that year, if they can be prepared for press in time, leaving the complete results for the years 1873 to 1875 to be included in the next volume ; the areas, as distinct from posi- tions, having been already printed in the volumes for 1874 and 1875. The usual magnetical and meteorological observations have been carried on, and considerable progress made with their reduction. The following are the principal results for magnetic elements in the year 1877 : — Approximate mean westerly declination 18° 57'. Mean horizontal force . . j 3-90i (in English units). ( 1799 (m metric units). o / // 167 38 46 (by 9-inch needles). 67 39 54 (by 6-inch needles). 67 40 40 (by 3-inch needles). Under the head of Extraneous Work, information is given as to the reduction of the Transit of Venus observations. At the date of the last Report the determination of the longitudes of the British stations was not quite complete (that of Kerguelen being then imperfect). But, under a demand from the House of Commons, a strong effort was made to finish all introductory calculations, and to effect computations of solar parallax by comparing all eye-observations of ingress of Venus among themselves, and all eye-observations of egress of Venus among themselves. The different stages of phenomena at the ingress were discriminated by Capt. Tupman with great care, and Sir George Airy believes with great general success, although Capt. Tupman himself has been induced lately to modify his interpretation of the observers' language in one or two instances. Finally, a report was made to the Government on July 5, giving as the mean result for mean solar parallax 8"76, the results from ingress and from egress, however, differing to the extent of o"*ii. A more, complete calculation by the Astronomer-Royal, including in one series the observations both at ingress an ! at egress, and recognising the possible errors of R.A. and N.P.D., gave sensibly the same mean result for parallax. This is liable to no error except from the interpretation of observers' language. All has subsequently been re-examined by Capt. Tupman ; different interpretations have, in a few instances, been put on the records ; several observations from colonial stations have been combined ; instead of using different phases in the observations (both of ingress and of egress), attempts have been made to ascertain the one phase of ' ' contact of limbs ; " the notes of a few unpractised observers have been rejected, and the result for parallax has been increased to 8"'82 or 8"'83. The numerous photographs taken at the various stations had been carefully measured by Mr. Burton, and have since been re-measured by Capt. Tupman ; and (by photographs of Mr. De la Rue's scale of equal parts) the measure of photographic distortion had been well ascertained. But the results from pho- tography have disappointed Sir George Airy much. The failure has arisen perhaps sometimes from irregularity of limb, or from atmospheric distortion, but more frequently from faintness and from want of clear definition. Many photographs which to the eye appeared good, lost all strength and sharpness when placed under the measuring microscope. It was once remarked to Sir George Airy, '« You might as well try to measure the zodiacal light. A final result, 8"- 17, the report states, was obtained from Mr. Burton s measures, and 8"'o8 from Capt. Tupman's. The Report next alludes to the progress made in the numerical lunar theory. The developments of the effect of every pos- sible error (expressed as a symbolical variation) in the co-efficients and arguments of the assumed lunar ordinates upon every term in the three fundamental expansions of— (i) Areas in the eclip- tic, (2) Radial forces in the ecliptic, (3) Forces normal to the ecliptic — have been computed and printed. The corresponding solar perturbing forces have been computed entirely for the first of these (care being taken to extend the decimal calculation further for those terms whose effect may probably be increased in solution of the equations, a process in which many figures are almost neces- sarily wasted), and partially forthe secondand third. Until all have been completed the Astronomer-Royal cannot draw any positive inference from the comparison of these terms with those of the ordinate expansions ; but a cursory collation of those' relating to me areas led him to suppose that there might be some error in tne computations of the annual equation and related terms. A most jealous re-examination has, however, detected nothing, and has confirmed Sir George Airy's belief in the general accuracy of the numerical computations. Finally, Sir George Airy strongly vu-ges upon the Board the necessity for the erection of a separate room for the library of the Observatory. COSMICAL RESULTS OF THE MODERN HEAT THEORY TN the Sitzungsherichte der Wiener Akadtmieder Wissenschaf/en, Herr J. Loschmidt has published a treatise on the equi- librium of temperature in a system of heavenly bodies with regard to gravitation, from which we note the following highly interest- ing details : — " Sir W. Thomson and Clausius simultaneously,^ drew from their researches the surprising conclusion that the whole universe at some definite period, however remote, would infallibly come to an end. First, all ponderous masses in the universe will eventually have united to one enormous heavenly body ; and secondly, upon this body all visible motion will have ceased, all forces having changed to mere molecular motion, which in the shape of heat of universally uniform temperature will be spread in this mass. This state of general death will then last eternally." Herr Loschmidt, in the course of his researches, has arrived at widely different conclusions. He begins by adopting the general view that the sun is in a state of slow progression of cooling, and that the time will unavoidably arrive when his sur- face will have solidified, long after all his planets have fallen in upon him, and after ^his upper and partly also his lower strata have assumed very nearly the temperature of the surround- ing universal space. But granting that thus a period of rest and death will have arrived for our solar system, Herr Loschmidt maintains, at the same time, that this period cannot be of unlimited duration ; the state of things just described can, according to his views, not be a state of equilibrium. *' The previous liquid state of the sun has caused a continued mixture of the warmer parts near the centre with the colder ones near the surface. Thus, however, the equilibrium of temperature, which requires a certain increase of temperature towards the interior, was rendered impossible. At the moment of solidification of the external layers the deeper ones will be far colder than the theory of the state of equilibrium demands. Because, according to this theory, the surface should have the temperature of universal space (about — 140° C. according to Pouillet), but this tempera- ture should rapidly increase towards the interior, reaching at the centre the enormous figure of 250,0x30,000° C. And it is just because at the moment of the beginning of solidification of the sun no such distribution of temperature took place in the interior, that the state above referred to cannot be of eternal duration. During an extremely long period, in spite of the low temperature of his surface, the solidifying sun will constantly absorb radiant heat from the store in the universe and will concentrate this heat in his interior. We suppose, for a moment, that it would be physically possible that this process of absorption is carried on to the end without the inclosed and dissociated gases in the interior breaking through the solidified surface or crust on account of their enormous tension. We then calculate the amount of heat accumulated in the end and find that it would easily suffice to raise the entire solar mass to |ths of that temperature which the state of equilibrium demands at the centre, viz,, to 100,000,000^ C. This figure is raised if the average molecule of the solar mass, instead of being supposed to be oi the density of oxygen, is taken to be of the density of carbonate of lime ; in that case it would be 125,000,000° C. We may compare these results to the quan- tity of heat which was.produced during the condensation of the solar system from the cosmical nebula, according to the theory of Laplace and Kant. Helmholtz has calculated that the heat thus generated would suffice, to raise the solar mass to a tem- perature of 28,611,000° C, if it is supposed to have the heat capacity of water. If, instead of water, other substances are taken as starting points, this temperature is considerably raised ; so in the case of carbonate of lime or silicic acid, the heat capacity of which is 0'2, the resulting temperature would be 140,000,000° C. " The close correspondence of both amounts speaks in favour of a periodicity in the history 0/ solar systems. In the first por- tion of its cosmical period the dark solidified body absorbs heat ^ [Clausius verified Thomson's statements about dissipation just as he verified (after experiment had proved it) J. Thomson's statement of the loweriEg of the freezing-point of water by pressure. Some Germans still call this " simultaneous discovery." Helmholtz, at least, does not.^Eo.] Jtme 13, 1878] NATURE 185 from universal space, and thus the temperature in its interior is gradually increased to an immeasurable extent. Then the moment arrives when the exterior crust can no longer resist the rising pressure of the inclosed masses, which have, of course, become gaseous. An explosion must result. The greater part of the mass which is converted into gas is dispersed over a great space, and thus by far the greater part of the accumulated heat is converted into gravitation and force of rotation o ithe dispersed masses. Now the second portion of the solar period begins, which, as a process of condensation of cosmical nebulae and subsequent slow cooling of the bodies formed by this condensa- tion, has been frequently discussed since the days of Laplace. " This is Ilerr Loschmidt's idea of the typical course of a cos- mical period, if fully developed according to the laws of heat. But he thinks that it is highly probable that this full develop- ment can be but rarely realised in the case of a solar system, since the duration of the heat-absorption will generally find a premature end in the impossibility of the external crust resisting the enormous pressure of the inclosed gases until the maximum of temperature is arrived "at. " Upon our sun, for instance, in a state of equilibrium of temperature, the surface temperature would be — 140° C, while at a depth of half a (German) mile we already would find a temperature of 3,000° C. Here all known substances would be in a state of liquid incandescence. The solid crust could therefore not be thicker than half a (German) mile. In this case, therefore, the typical course described would evidently be interrupted prematurely by an explosion. "The consequences of a solar eruption of this kind are natu- rally very different under different] conditions. Thus with a comparatively small accumulation of heat and corresponding low tension, the result would be simply the return to incandescence of a dark heavenly body, while with greater concentration of heat some portions [may be separated from the principal mass and carried to great distances, where, forming themselves into planets, they would revolve round the principal mass in elliptical orbits. This theory, therefore, easily explains the origin of planets, like those of our system, and the manner in which they were carried to their respective places and are provided with '.heir forces of rotation and revolution, and also how after all in the principal solar mass a quantity of heat would remain, which would cause a far higher temperature upon its surface than exists at present upon our sun. The principal solar mass would thus be again enabled to radiate light and heat to its planets and into the universe, until again the moment of solidification and re- beginning of absorption of heat has arrived. The total result under the most varying circumstances always remains the same : periodicity of the dynamical solar phenomena. " If finally we look for proofs for our theory in the heavens, we direct our attention to dark bumt-out suns on the one hand and to suddenly appearing new suns on the other. It is strange that modem times have given examples of both classes of pheno- mena. As a representative of the first class we have the dark companion of Sirius, calculated in advance by Bessel from the disturbances, and actually seen by A. Clark and Pond In 1862. This enormous mass has only just been rendered visible by the most powerful instruments, although it is nearly seven times the size of our sun. A second example is the companion of Procyon which, though calculated with certainty, has not yet been seen on account of its still greater darkness. Examples of the other class we have in the well-known new stars of Tycho Brahe and Kepler, besides the new star in Corona of 1866 and the one recently seen by Schmidt and others in Cygnus (December, 1876). In both these latter cases eruptions of incandescent hydrogen were proved beyond doubt by spectral observations." THE METEOR A METEOR of unusual brilliance was seen of the " fire-ball" ■^ type on Friday night by several correspondents. All agree that the time was about 9.50, the moon at the time being in her second quarter, and about 30° above the horizon in thewest-south- west. At Twickenham its observed course was from south-west to north-west passing the azimuth of the moon at the time 69° from south to west, at an altitude of about 14°, its path being nearly parallel to the horizon, or declining very slightly towards its disappearance, which was sudden, at 9h. 52m. 30s. Greenwich mean time. Colour, bright emerald green ; apparent diameter, about one-third of that of the moon, this being the greater diameter of the, elliptical figure. The light thrown by the meteor in this locality was decidedly green. Mr. Lecky, writing from the Scientific Club, states that the course of the meteor was about 90° below the moon, its motion very slow, and it became extinguished rather suddenly, without any appa- rent bursting, when it had passed about the same distance to the north of the moon. The meteor appeared to Mr. Lecky to be about the same size as the moon. Mr. L. J. Whalley saw it from the Brompton Road. Facing west he saw it pass from south to north, its path being inclined downwards at a few degrees to the horizon, and its altitude about 30". The fore-part appeared rounded in shape, and of a bright green colour (like nickel sulphate), whilst the tail tapered off, and was of a red to a purplish tint. Mr. Walter Fowler saw it from Cambridge. Its path, he states, was from south to north, almost parallel with the horizon, with a slight declination northwards, IDuring its course, which lasted about twenty seconds, it emitted innumerable sparks variegated in, colour. Another correspondent saw it from London Street, Green- wich. Its apparent altitude, he states, was about 28° or 30° above the western horizon, and it passed horizontally over the tops of the houses in a direction about two points to the west of north. He observed it for about three seconds. It appeared in passing under the moon to be about 6° or 8° underneath her lower limb, and about the same degree of brightness and equal to it in size. The meteor, he states, had a tail about equal to six or seven diameters of its nucleus ; the central part of the tail and the nucleus were of a pale orange hue and fringed with violet rays. The tail was in the line of motion, and was not a perfect cone, but appeared to expand into a fin-like form at the extremity. Mr. F. J. Richardson, of Dimchurch, near Rugby, observed the meteor, "of considerable size," cross the sky, apparently about 30° above the horizon. The direction of its path was from south to w-jst, and its colour appeared a mixture of orange and green. It remained visible for about thirty or forty seconds, and then suddenly disappeared. Mr. R. Langdon, writing from Silverton Station, Devon, states that it moved slowly towards Ursa Major, and exploded a little beyond that constellation. Its colours were, first, very pale blue (nearly white), then deep blue, and finally, the several fragments after explosion were blood-red. Dr. Morison saw it from Jersey. When first seen it was about 30" from the zenith in a direction nearly due north. The diameter of its disc, which was apparently circular, was rather more than half that of the full moon, which it far surpassed in brilliancy, shining with a beauti- ful white light. The meteor descended towards the horizon, leaving a very faint luminous trail behind it, and was lost to sight, while still remaining entire, behind a high wall. It was altogether visible about thirty seconds. Our Paris correspondent writes that a splendid meteor was seen in the department of Aisne and at Versailles about ten o'clock in the evening, travelling westwards at a small altitude. It was in diameter about one -sixth that of the moon, the brilliancy admirable, and the tail four or five times the length of the moon's diameter. No noise was heard. Mr. Denning, of Bristol, writing to the Times, states that the meteor had a very long path, almost horizontal, from east to west, which it traversed with a gradual motion, casting off a short train of sparks as it sailed along, and showing sensible variations in the brilUancy of its pear-shaped nucleus. The position of the observed part of its path was noted from l° above the star Spica Virginis to 6° above the moon, but to include the whole extent of its visible course the line must be extended in each direction, and have a length of at least 75° from, say, slightly below Alpha Librse to slightly above Alpha Leonis, running almost parallel with the ecliptic. The meteor was con- siderably brighter than Venus, and perhaps equal to a body one- fourth of the moon's diameter. Mr. H. Middleton Rogers states that while walking along a footpath close to Knole Park, he saw it passing apparently from south to north, very nearly parallel to the horizon, with a very slight declination towards the north. When he first saw it it was about 5° from the moon, (taking the moon's diameter roughly at half a degree.) It passed slowly\long about 3° below the moon, or about 30° above the horizon, and continued its course for about 20° further towards the north, when it suddenly disappeared. The light was of a very pale gi-een, as nearly as possible like the light of a glow- worm highly intensified. As it passed under the moon its brilliancy^'caused the moon to look of a muddy yellow colour— i86 NATURE \ymie 13, 1878 like a street lamp in a November fog. A Tines correspondent at Cheltenham says that the path of the body was almost due east and west, and the apparent time of flight about 20". The meteor was also observed at Southampton, Tnnbridge Wells, and Beckenham. UNIVERSITY AND EDUCATIONAL INTELLIGENCE The Sedgwick Memorial Committee (Cambridge) have passed the following resolution, which has been sent to the Vice- Chancellor : — " That a communication be made on behalf of the Committee to the University to the effect that a sum of about 12,000/. is now at their disposal for a memorial to the late Prof. Sedgwick, and that the Committee are prepared to apply this money towards the erection of a new geological museum when a plan satisfactory to the Committee has been approved by the Senate." On the nomination of Prof. Miller, Mr. W. J. Lewis, M.A., Fellow of Oriel College, Oxford, has been approved as Deputy Professor of Mineralogy for twelve months, from October i, 1878, Prof. Miller assigning to Mr. Lewis two-thirds of his stipend. Mr. J. A. Ewing, B.Sc, F.R.S.E., has been appointed Professor of Mechanical Engineering in the University of Tokio, Japan. SCIENTIFIC SERIALS Bulletin de r Academie Royal de Belgique, No. i, 1878. — In researches on Daltonism, here described, MM. Delboeuf and Spring used a solution of fuchsine between two convergent plates of glass (the red is wanting in M. Delbceuf's sight). Thus a suitable thickness of red could be readily selected, and it was found that colours previously confounded showed notable differences. A solution of chloride of nickel interposed between objects and the eye produces in non-Daltonians the same con- fusion as that of Daltoni'ans. Fuchsine opposes and destroys the effect of chloride of nickel : so that the non-Daltonian in whom the latter produces confusions ceases to have thee when he looks also through the fuchsine. Daltonism is regarded as merely an exceptional exaggeration of a peculiarity found in all eyes to a certain degree. — M. Terby furnishes fifteen figures of Mars as observed during the opposition of 1877. — The physio- 1 ogical action of Gelsemine, on respiration, circulation, and tem- perature, is described by MM. Putzey and Romiee. — M. de Koninck announced that his son found, in the Ardennes, the very rare mineral carpholite, hitherto only met with in the Plarz and Bohemia. No. 2. — From experiments with regard to the fertilising action of the grey chalk of Ciply, in Belgium (which contains 11 '50 per cent, of phosphoric acid), M. Petermann concludes that bicalcic phosphate, called precipitated phosphate, and the phos- phates of iron and alumina, have the same agricultural value as the phosphoric acid of soluble phosphates, that is, their phos- phoric acid may be immediately assimilated by plants. lie therefore advises the disuse of the Cipley Chalk, and he con- siders it can only be utilised in agriculture after its transforma- tion into precipitated phosphate. (M. Stas thinks this conclusion too absolute.) — M. Quetelet reviews observations of the move- ments of the magnetic needle at Brussels from 1828-76. The magnetic line diverges very little from a central axis, with which it makes an angle of about 5°. It turns round this axis in a direction opposite to that of the earth's diurnal motion ; the angle described annually is about 42'*2, and the complete revo- lution would appear to be effected in 512 years. The secondary movements and accidental displacements do not sensibly affect the principal secular movement. — M. Donny recalls experiments he made, in 1S43, with Prof. Mareska, on liquefaction of gases. They often compressed air (with a hydraulic pump) in the capil- lary part of a manometer to more than 500 atm., and M. Donny thinks they may have liquefied the gas without knowing it. — MM. Navez describe a combination of an induction coil with the telephone for speaking at great distances. The induced currents are sent into the line, while the sending instrument is inserted in the local circuit connected with the battery. The receiving telephone is somewhat modified. — The subjects for prizes offered by the Academy for 1879 are announced in this number. Reale Istitnto Lombardo di Scienze S Lettere. Rendiconti, vol. xi. fasc. iv.-vi. — We note the following papers in these numbers : — Deformative hypertrophy of the nails, by M. San- galli. — Claustrophobia, by M. Verga. — Some experiments with the telephone, by M. Serpieri. — On the dominant diseases of the vine, by MM. Garovaglio and Cattaneo. — On the kinematics of a solid body, by M. Bardelli. — Lecture experiment (illus- trating liquefaction of gases), by M. Brugnatelli. — An experi- ment on electrostatic induction, by M. Cantoni. — On a case of heterogenesis observed in nature, by MM. Battista and Corrado. — Reduction of argentic and ferric chloride, by M. Tommasi. — Geological observations on the Carso di Trieste and the valley of the J\ecci with reference to water supply, by M. Taromelli. The Bulletin di V Academie Iinpcriale des Sciences de SL Petersbourg (t. xxiv. No. 4) contains the following papers of interest : — Development into converging series of the odd nega- tive powers of the square roots of the function i - 2 »; U -f tj-, by Dr. J. Backlund. — Variation of the volume of liquids through the effect of temperature, by M. Avenarius. — On some new forms of crystals of ilmeno-rutile, by P. Jeremejew. — On the development of excrescences (cephalodia) on the thallus of Licheny Peltigei-a aphtJiosa, Hoffm., by M. Babikoff. — On a new case of divisibility of the numbers of the form 2-™-l-i, found by the Rev. J. Pervouchine, by V. Bouniakowsky. — A note on the opposition of planets during 1877, by A. Sawitch. — On aa extremely slight earthquake observed by means of a very delicate level on May 10, 1877, by M. Nyren. Morphologisches yahrbuch, vol. iv., supplement, dedicated to Carl von Siebold. — On the cranial skeleton of alepocephalus, a clupeoid fish, by Prof. Gegenbaur, two plates, 42 pp. — Fossil vertebrse, by C. Hasse, dealing with the relationship of the genus Selache ; two plates. The author believes this genus to have developed from Carcharodon in the tertiary period. — The gorilla's brain and the third frontal convolution, by Prof, von Bischoff, a controversial article referring to Prof. Broca's researches and views. — Contribution on the coral family Antr- patharia, by G. von Koch. — The disposition and development of elastic tissue, by L. Gerlach, with two beautiful plates. — The development of the muscular structure of the human foot, by G. Kuge, 36 pp. one plate. The Notizblatt des Vereins fiir Erdkunde lu Darmstadt (iiu xvi. Nos. 181 to 192) contains some interesting statistical data from the Hessian Central Statistical Office. The papers of geological interest are : On the crystalline lime of Auerbach on the Bergstrasse, by R. Ludwig. — On the minerals found in the cavities of the melaphyr from Traisa and in the basalt of the Rossberg, by the same. — On the minerals and fossils found near Ilering (Ilessen), by the same. — Comparative account of the products of all Hessian mines during the years from i860 to 1876, by Herr Tecklenburg. — On the fauna of the real Cyrene emery of Sulzheim, near Woerrstadt (Hessen), by Dr. O. Boettger. SOCIETIES AND ACADEMIES London Royal Society, May 2. — " Preliminary Notes on Ex- periments in Electro-Photometry." By Prof. James Dewar^ F.R.S., Jacksonian Professor, University of Cambridge. Edmond Becquerel, in the year 1839, opened up a new fielii of chemical research through the discovery that electric currents may be developed during the production of chemical inter- actions excited by solar agency. Hunt, in the year 1840, repeated, with many modifications, Becquerel's experiments, and confirmed his results. Grove, in 1858, examined the influence of light on the polarized electrode, and concluded that the effect of light was simply an augmentation of the chemical action taking place at the surface of the electrode. Becquerel, in his well-known work, " LaLumiere," published in 1868, gives details regarding the construction of an electro- chemical actinometer formed by coating plates of silver with a thin film of the sub-chloride, and subsequent heating for many hours to a temperature of 150° C. Egeroff, in 1877, sugested the use of a double^ apparatus of Becquerel's form, acting as a differential combination, the plates of silver being coated with iodide instead of chloride. The modifications of the halogen salts of silver when subjected to the action of light have up to the present time been used most jfune 13, 1878] NATURE 87 successfully in the production of electric currents, and although mixtures of photographically sensitive salts have been shown by Smee to produce currents of a similar kind, yet no attempt has been made to examine the proper form of instrument required for the general investigation of electrical actions induced by light on fluid substances. This subject has occupied my attention for some time, and the completed investigation I hope to present to the Society. In the meantime the following description will give an idea of the method of investigation. A little consideration shows that the amount of current pro- duced by a definite intensity and quality of light acting during a short' period of time on a given sensitive substance in solution, is primarily a function of the nature, form, and position of the poles in the cell relatively to the direction in which the light enters, and the selective absorption, concentration, and con- ductivity of the fluid. Diffusive action taking place in such cells complicates the effects and is especially intricate when insoluble substances are formed. In order to simplify the investigation in the first instance, poles that are not chemically acted upon, and a sensi- tive substance yielding only soluble products on the action of light, were employed. For this purpose platinum and chlorous acid or peroxide of chlorine were selected. The best form of cell had one of the poles made of fine platinum wire fixed as closely as possible to the inner surface where the light enters, the other pole being made of thicker wire placed deeper in the fluid. As the action is confined to a very fine film where the light enters, the maximum amount of current is obtained when the composition of the fluid is modified deep enough to isolate tem- porarily the front pole in the modified medium. Under these conditions the formation of local currents is avoided, and the maximum electromotive force obtained. In cells of this construction the amount of current is inde- pendent of the surface of the fluid acted upon by light, so that a mere slit sufficient to expose the front pole acts as efficiently as a larger surface. This prevents the unnecessary exhaustion of material, and enables the cell to be made of very small dimen- sions. By means of such an apparatus the chemical actions of light and their electrical relations may be traced in many new directions. The amount and direction of the current in the case of chlorous acid is readily modified by the addition of certain salts and acids, and thus electrical variation may be produced, resembling the effects observed diuring the action of light on the eye. Certain modifications taking place in chlorous acid that has been prepared for some time increase its sensibility, and as a general result it is found that the fluid through these alterations increases in resistance. "We hive thus an anomalous kind of battery where the available electromotive force increases with the resistance. The addition of neutral substances which increase the resistance without producing new decompositions, improves the action of the cell. Care has to be taken to use the same apparatus in a series of comparative experiments, as infinitesimal differences in the con- tact of the active pole render it difficult to make two instruments giving exactly the same results. Cells have been constructed with two, three, and four poles, and their individual and combined action examined. Quartz surfaces have also been employed instead of glass, thus enabling the chemical opacity of different substances to be determined. The electrical currents derived through the action of light on definite salts are strong in the case of ferro- and ferri-cyanide of potassium, but remarkably so in the case of nitroprusside of sodium. Of organic acids the tartrate of uranium is one of the most active. A mixture of selenious acid and sulphurous acid in presence of hydrochloric acid yields strong currents when subjected to light in the form of cell described. The list of substances that may be proved to undergo chemical decompo- sition is very extensive, and full details will be found in the completed paper. Geological Society, May 8. — Henry Clifton Sorby, F,R,S,, president, in the chair, — Charles Preller Sheibner, Ph.D., was elected a Fellow of the Society, — The following communica- tions were read : — On the glacial phenomena of the Long Island, or Outer Hebrides (second paper), by James Geikie, F,R.S. In this paper the author gave some additional notes on the glacia- tion of Lewis, and a detailed account of the glacial phenomena of Harris and the other islands that form the southern portion of the Outer Hebrides. In concluding, the author pointed out that we may now arrive at a true estimate of the thickness attained by the ice-sheet in the north-west of Scotland. If a line be drawn from the upper limits of the glaciations in Ross- shire (3,000 feet) to a height of 1,600 feet in the Long Island, we have an incline of only i in 210 for the upper surface of the ice -sheet ; and of course we are able to say what thickness the ice reached in the Minch. Between the mainland and the Outer Hebrides it was as much as 3,800 feet. No boulders derived from Skye or the mainland occur in the Till of the Outer Hebrides, and this was explained by the deflection of the lower portion of the ice-sheet against the steep wall of rock that faces the Minch, The under part of the ice that flowed across the Minch would be deflected to right and left against the inner margin of the Long Island ; and the deep rock-basins that exist all along that margin are believed to have been scooped out by the grinding action of the deflected ice. Towards the north of Lewis, where the land shelves off gently into the sea, the under strata of the ice-sheet were enabled to creep up and over the district of Ness, and thus gave rise to the lower shelly boulder- clay of that neighbourhood, which contains boulders derived from the mainland. The presence of the overlying interglacial shell-beds proves a subsequent melting of the ice-sheet, and a depression of the land for at least 200 feet. The overlying shelly boulder-clay shows that the ice-sheet returned and over- flowed Lewis, scooping out the older drift-beds and commingling them with its bottom moraine. The absence of kames w'as commented upon, and shown to be inexplicable on the assump- tion that such deposits are of marine origin ; whilst if they be of torrential origin their absence is only what might be expected from the physical features of the islands. The only traces of post-glacial submergence are met with at merely a few feet above present high-water mark. — Cataclysmic theories of geological climate, by James Croll, F.R.S. Communicated by Prof. Ramsay, F.R.S. The author commenced by calling attention to the great diversity of the hypotheses which have been brought forward for the explanation of those changes in the climate of the same regions of the earth's surface which are revealed by geological investigations, such as alterations of the relative dis- tribution of sea and land, of the ecliptic, and of the position of the earth's axis of rotation, all of which, he maintained, have proved insufficient or untenable. Sir William Thomson has lately maintained that an increase in the amount of heat con- veyed by ocean-currents combined with the effects of clouds, winds, and aqueous vapour, is sufficient to account for the former prevalence of temperate climates in the Arctic regions, and this view, the author stated, he had himself been contending for for more than twelve years. He thinks, however, that alter- ations in the eccentricity of the earth's orbit is the primary motive cause, whilst Sir William Thomson believes this to be the sub- mergence of circumpolar lands, which, however, in miocene times, appear to have been more extensive than at present. He pointed out that a preponderance of equatorial land, as assimied by Sir Charles Lyell to account for the milder climate of Arctic regions in miocene times, would rather tend to loss of heat by rapid radiation into space, whilst water is remarkably powerful as a transporter of heat, so that, in this case, equatorial water rather than equatorial land is needed. In speaking of the glacial climate, the author maintained that local causes are in- sufficient to explain so extensive a phenomenon. He indicated that we are only too prone to seek for great or cataclysmic causes, and although this tendency has disappeared from many fields of geological research, this is not the case in all. His explanation of the causes of a mild climate in high northern latitudes is as follows : — Great eccentricity of the earth's orbit, winter in perihelion, the blowing of the south-east trades across the equator perhaps as far as the tropic of Cancer, and impul- sion of all the great equatorial currents into northern latitudes ; on the other hand, when, with great eccentricity, the winter is in aphelion, the whole condition of things is reversed ; the north-east trades blow over into the southern hemisphere, carry- ing with them the great equatorial currents, and glacial condi- tions prevail in the northern hemisphere. Thus those warm and cold periods which have prevailed during past geological ages are regarded by the author as great secular summers and winters. — On the distribution of ice during the glacial period, by T. F. Jamieson, F.G.S. The author believes that a study of the dis- tribution of ice during the glacial period proves that the greatest NATURE {June 13, 1878 accumulation of snow took place in precisely those districts which are now characterised by a very heavy rainfall, and he pointed out how exactly this is in accordance with the views of Prof. Tyndall as to the conditions most favourable to the deve- lopment of glaciers. Zoological Society, May 21. — F. D. Godman, F.Z.S., in the chair. — A communication was read from Lieut. -Col. R. H. Beddome, C.M.Z.S., containing the description of a new genus and species of snakes, of the family of Calamariidse, from Southern India, proposed to be called Xylophis indicus. — Mr. P. L. Sclater, F.R.S., read the tenth of a series of reports on the collection of birds made during the voyage of H.M.S. Challenger, containing an account of the birds of the Atlantic Islands and Kerguelen's Land, and of the miscellaneous collec- tions made by the expedition. — Mr. J. Wood Mason, F.Z.S., described several new or little known Mantidae from India, Australia, and other localities.— Mr. H. W. Bates, F.Z.S., read a paper containing the description of new genera and species of Geodephagous Coleoptera from Central America, belonging to the families Cicindelidae and Carabidse. — Mr. G. French Angas, C.M.Z.S., read the description of a new species of Tudicula, which he proposed to name T. inermis. — A communication was read from the Marquis of Tweeddale, F.R.S., being the ninth of his contributions to the ornithology of the Philippines. The present paper gave an account of the collection made by Mr. A. H. Everett in the Island of Palawan, and contained the de- scriptions of nine new species, namely, Tiga everetti, Dicrurus palawanensis, Broderipus palawanensis, Trichostoma rufifrons, Dryniocataphus cinereiceps, Brackypus cinereifrons, Criniger palawanensis, Cyrtostomus aurora, and Corvus pusillus. The collection likewise contained three examples of the remarkable Polyplectron emphanfs, of which the locality was previously unknown, and specimens were excessively rare. — Prof. A. H. Garrod, F.R.S., read a paper in which he gave a description of the tracheae of Tantalus loailator and of Vanellus cayennensis. — A second paper by Mr. Garrod contained some notes on the anatomy of the Great-headed Maleo (Megacephalon maleo). Victoria (Philosophical) Institute, May 31, — Annual Meeting ; the president, the Right Hon. the Earl of Shaftes- bury, K.G., in the chair. — From the annual report it appeared that the number of members is now 756. — The Address was delivered by Principal Rigg, D.D., and contained a review of various systems of philosophy now popular. Paris Academy of Sciences, June 3. — M. Fizeau in the chair.— The following among other papers were read :— Direct determi- notion at sea of the azimuth and route of a ship, by M. Faye. This is for iron ships, and involves keeping the ship some time in a fixed direction indicated by the log-line and determined astronomically. The log is slightly modified in form. — New researches on the fossil mammalia of South America, by M. Gervais. The author has examined the recent collections of MM. Ameghino, Brachet, and Larroque, from the province of Mines, in Brazil, and some parts of the Argentine Republic. He is able to add some new details about the Toxodon, and describe, mter alia, a new species of Machairodus, and two new species of Glyptodon (the species of which, he estimates, cer- tainly exceed a 'dozen).— On the chalk of the Central Pyrenees, by M. Leymerie. He finds there a bed immediately under the first eocene layer, containing quite a special marine fauna, among which are numerous urchins. — M. Cornu was elected member in the section of physics in place of the late M. Becquerel.— Direct fixation of carbonic acid, sulphurous acid, and phtalic anhydride, on benzine ; synthesis of benzoic acid, hydride of sulphophenyl, and benzoylbenzoic acid, by MM. Friedel and Crafts. The authors suppose in these syntheses an organo -metallic combma- tian of aluminium by the reaction of the chloride of this metal on the hydrocarbons.— On the manufacture of cast manganese and on the volatility of manganese, by M. Jordan. More than 100,000 kil. of this cast manganese (from treatmg ores of manganese in the blast furnace) have already been supplied to French steel works. Manganese is volatile at the temperature of metallurgical fiirnaces; and this fact explains several anomalies remarked in the manufacture of very manganesised products.— On Daltonism; sanitary precautions, and preventives, by M. Favre. There are in France more than 3,000,000 persons affected with Daltonism ; the number of women affected is to that of men as i : 10. Nine out of ten cases can easily be cured in youth ; the best means being methodic exercise on coloured objects. This should be attended to in all schools, and mothers should seek to develop the chromatic sense in their children. No one should be admitted to the service of railways, the. navy, or schools of painting, without being examined in colours. No Dal- tonians should be charged withservice involving the use of coloured signals. — Information was given regarding observation of the tran- sit of Mercury in the United States. — On the densities of vapour, by M. Troost. He describes the behaviour of vapour of acetic acid, hyponitric acid, sulphur, and hydrate of chloral. Sulphur vapour behaves like ozone, whose density is independent of pressure, and whose transformation into oxygen takes place in proportion as the temperature is raised. — On metallic allotropy, by M. Schutzenberger. By electrolysis of metallic solutions, allotropic varieties of other metals besides copper {e.g. lead) may be got. It is impossible to decide by direct experiment whether or not allotropic copper contains occluded hydrogen eliminable at 100°. In any case the proportion of hydrogen could not exceed 0*03 per cent. — Method of determination and separation of stearic acid and oleic acid proceeding from saponification of tallow, by M. David. The principle of this process is based on the new fact that when into an alcoholic solution of oleic acid one pours acetic acid drop by drop, a moment comes when, suddenly, the oleic acid separates completely. — On the structure of nerves in invertebrates, by M. Cadiat. In Crustacea, insecta, and annelida, the nerves have no myeline, which in vertebrates is found between the cylinder axis and the wall proper of the tube (the grey fibres of the great sympathetic excepted). In gasteropodous and acephalous molluscs the sheath of Schwann is almost always wanting. — On the relations be- tween the volume of motor or sensitive cells of nervous centres, and the length of passage of the impressions transmitted, by M. Pierret. The dimensions of the nerve-cells are in direct ratio of the distances which the motor incitations proceeding from them, or the sensitive excitations reaching them, have to traverse. — There were several other papers on chemical subjects, deter- mination of arsenic in volumes, reciprocal combinations of metallic sesquisulphates, some combinations of platinum, nitro- genised acids derived from acetones, cyanide of ethylene, researches on peptones, &c. CONTENTS Pagb Ethnology of North-Wkst America. By Prof. A, H. Savce . . 165 Culley's Practical Telegraphy 166 Our Book Shelf:— ,,...,. x, . , Jordan's "Manual of the Vertebrates of the Northern United States, Including the District East of the Mississippi River and North of North Carolina and Tennessee, Exclusive of Marine Species " 167 Letters to the Editor :— The Phonograph and Vowel Theories.— Prof. Fleeming Jbnkin, F.R.S. ; J. A. Ewing 166 Extinct and Recent Irish Mammals.— Prof. W. Boyd Dawkins, F.R.S 169 Alterrjate Vision.— J. I. R i6g The Eskimo at Paris.— Dr. J. D. E. Schmeltz 169 The Telephone.— John Browning ; J. F. W. 169 Meteor. — W. A. Sanford 170 Multiple Rainbow.— R. S. •••••,•; A '7° Opening of Museums on Sundays.— Dr. W. H. Corfield ... 170 The Fisheries of British North America, I. By Dr. William B. Carpenter, F.R.S •, ; W. o t^ '7° The Microphone. By Jambs Blyth, M.A., F.R.S.E 172 Resting Spores. By Prof. E. Perceval Wright 173, Prof. C. F. Hartt • i74 The Dark Continent {With Jllustrattons) 175 Our Astronomical Column : — The Transit of Mercury, 1868, November 4 179 Brorsen's Comet of Short Period '79 MiraCeti i°° CtRAGRAPHICALi ^^OXES ««•••••"•••"•"••' loO On a New Method for Discovering and Measuring /Eolotropy of Electric Resistance Produced by ^olotropic Stress in a Solid. By Sir W. Thomson 180 N©tes ' The Royal Observatory ••••••,„ 'o^ CosmicalResults OF the Modern Heat IHEORY 184 The Meteor '°| University and Educational Intelligence 180 Scientific Serials \, Societies and Academies ...-...•- Errata.— In Mr. Broun's article on Cosmic Meteorology, vol. xviii. p. 152, ist column, line 7, for 464, read 8,464; and p. 153, ^ad column, line 16, for "relate to magnetical and meteorological phenomena, read " relate magnetical to meteorological phenomena. NA TURE 189 THURSDAY, JUNE 20, 1S78 TERTIARY FLORA OF NORTH AMERICA United States Geological Survey of the Territories — Tertiary Flora. By L. Lesquereux. VoL vii. (Washington, 1878.) THE volume for the present year, of considerable thickness,' is entirely occupied by a most important work upon the Tertiary flora of North America. Although the geological and stratigraphical portions of the work are not so distinctly set out as they might have been, this by no means lessens the palasontological value of the work which is more especially in the author's province. The country occupied by the Lignitic beds, described in the present volume, is a plain stretching for 600 miles between the Missouri and the Rocky Mountains. The ascending gradient is not more than ten feet per mile and the beds are horizontal ; the whole Lignitic series is therefore exposed in sequence from east to west, com- mencing with the Cretaceous lignites, described in a previous volume (which occupy about one-third of the area), and ending with the newer Miocene or perhaps Pliocene beds. The Tertiary Lignitic coal-fields of Western America alone, were estimated by Taylor in 1848 to occupy the enormous area of 250,000 square miles, or twice the area of Great Britain ; but M. Lesquereux supposes that coal- beds of other ages must be included, and he points out (p. 7) that nothing positive was known of the great North American Lignitic until Dr. Hayden began his researches in 1854, and to the remarkable accuracy of whose work he pays a well-merited tribute. Their area on the Upper Missouri is stated at not less than 100,000 square miles, and in the succeeding para- graph it is estimated at about 140,000 miles. This is their extent in that region of the United States alone, but their actual extent is much greater, since they stretch far across the border into British possessions; they have been traced southward along the base of the Laramie range to beyond the Arkansas River, and by outliers as far as Albuquerque, and again westward they are connected with the coal- fields of the Great Colorado Basin and the Laramie Plains. Under the heading " Stratigraphy" we are told that there is no unconformability, physical, or other break in the sequence from the so-called Cretaceous lignites to the Tertiary Lignitic. It is then mentioned that there is a transition bed of coarse sandstone, irregularly deposited, whose thickness is not stated. There are next given detailed sections, some of Upper and some of Lower Lignite, none of them, however, presenting a thickness of more than 480 feet. It is strange that only a small para- graph (p. 12), extracted from Hayden' s Report in 1874, to which no prominence is given, warns us that the Lower Lignites are of vast thickness — 3,000 to 5,000 feet, but whether this thickness is all of Tertiary or the older lignites we are left to ascertain elsewhere, whilst we only incidentally gather that there is an Upper and a Lower Lignite. The faulty construction of the introduction arises from M. Lesquereux having too loosely strung ' About 380 pages and 65 plates. Vol. XVIII. — No. 451 together extracts from various works, which render it so disconnected as to be all but useless except to those who possess a previous knowledge of the subject. The thick- ness of, and as far as possible, the area occupied by, each division of the Lignite should have been as clearly set out as we find them in Hayden' s Report for 1S74, which is frequently referred to in the present work. The third section is almost wholly occupied by verbatirrt^ extracts from the arguments of Professors Hayden", Meek, and Cope as to the age of the Lignitic. The conflicting nature of the evidence is apparent, the balance, apart from the botanical evidence, not here referred to, being decidedly in favour of Tertiary age. In the seventh chapter of the Annual Report, 1874, Peale had already given, in tabulated form, the views of authorities in regard to the age of each group of the Lignites which have been referred to Tertiary. In a much condensed form this might have been introduced into the present Avork with advantage. None of the Lignitic freshwater mollusca have been specifically iden- tified with foreign forms ; the vertical distribution of these being well-marked and limited, the evidence they would present should be of great value. In this section (p. 24) a table is introduced incidentally^ showing four groups of strata, .which, omitting the lithology, the column of localities and all mention of fossils other than vegetable, reads thus : — Names. Fort Union group ; Lgnite group. Wind River deposits. White River group. Loup River beds. Sub-divisions. "Great number of dicotyle- donous leaves, stems, &c. ; Platanus, Populus, &&; with very large leaves of true Fan Palms." " Petrified wood." " Petrified wood." [No vegetable remains mentioned]. Thickness. 2,000 feet cr more. 1,500 to 2,000 feet. 1,000 feet or more. 300 to 400 feet. Foreign e:iuivalents. Eocene. ? Miocene. Pliocene. From this table we should certainly conclude that the leaf remains were confined to the " Lignite group," and consequently that the botanical part of the work referred only to fossils of Eocene age. The work being on the " Lignitic " we are still further confirmed in this opinion, and dismiss the overlying "deposits," "group," and "beds " from our minds. With this impression we come to " Part II. Description of the Tertiary Fossil Plants,'" and are in no way prepared for such a surprise as is reserved for us in Part III., 273 pages further on, on finding that the leaves are figured and described from beds of Eocene, Miocene, and Pliocene age indiscriminately. In the second and third parts M. Lesquereux is evi- dently working at more congenial subjects, and deserves praise for the painstaking way in which he has described the material before him. The truism that all determi- nations based upon leaves alone are provisional and un- trustworthy, has deterred English botanists from working at our Tertiary floras ; and thus while we see magnificent works on this subject brought out in France, Germany, IQO NATURE {June 20, 1878 Austria, Italy, Switzerland, and America, no work of any importance has appeared in England. But though they are so, this in no way lessens the value of descriptions and figures for the purpose of comparing different floras, their distribution, the climatal conditions of each age, and inferring the relative age of isolated remains of land surfaces, volcanic outbursts, elevations, &c. It matters less whether a widely spread leaf-form is referred to oak or beech, than to ascertain that it is characteristic of a definite age and had a definite distribution. Fortunately there are palaeo-botanists like M. Lesquereux who, having done their utmost to assign a leaf to its right genus, are content to wait for certain proof until the discovery of fruits and more perfect specimens. Among the more interesting plants described are a Lycopodium and three species of Selaginella, all well pfeserved. The discovery of these is remarkable, as M. Lesquereux states that none of the Lycopodiaceae had previously been known between Oolitic and recent times. The ferns are also of especial interest. Besides Lygo- dium and Pteris (which forcibly recall both Eocene and Miocene European forms), we have in Gymnogramina Hayde?iu, from the Lower Lignite, a form also common at Bournemouth (now described from more perfect fronds as an Anemia), and to the Aix-la-Chapelle flora as Asple- niumForsteri, Deb. and Ett., and to Suzanne as Asplenium subcretacetim, Saporta. Conifers and palms are nume- rous, but being fragmentary are less easy to compare Avith those of other localities. Still less so are other Monocotyledons, except a single Miocene Sinilax leaf identified with a European species. The Dicotyledons are very numerous, 212 species being described. Of these the leaves ascribed to My- rica, a large group mostly from the Upper or Miocene series, have an Eocene aspect. The forms assigned to Betula, Alnus, Carpinus, Cotylus, and Fa^us, are very similar to each other, and appear, from the figures, to have perhaps been too much subdivided. Any of these might be identified with leaves from Bournemouth, where the beds are undoubtedly Eocene. The leaf- forms from the Lower Lignite described as oaks have been deter- mined with considerable hesitation, and are of most dissi- milar character, as we see indicated by such specific names as 2. piatinia, Q. vibi^rni/olta, Q. negundioides. They have been classed as oaks on account of greater or less resemblance to species so described by European authors holding very diverse views. The single Castanea is indis- tinguishable from an Alum bay-leaf. In the simple forms of the Saliciniae we have perhaps the nearest approach in cha- racter to European forms, and a large proportion of them will be found identical with leaves from Bournemouth. We must not, however, attach undue importance to the apparent similarity of simple ovate or lanceolate leaves especially when comparisons are made from drawings only. The poplars form a large group, but, considering the variability of their leaves, species appear to have been unnecessarily multiplied, some being determined from fragments of leaves and others from single specimens, as P. melanarioides, P. 7nelanaj'ia, &c. P. Zaddachi is a familiar leaf in the English Bagshot and Woolwich beds, and in the Arctic beds, so-called Miocene ; P. Richard- soni also appears identical with this form. Leaves, so similar to each other in outline and variation, that from the plates they can scarcely be distinguished, are described respectively as Querctis platania, Popidus Icevi- gata, and Platanus Raynoldsii and we long to know why they are so distinctly separated. The only leaf ascribed to Ubmcs is from the Miocene stage, but appears identical with a Bournemouth form. Again Qucrcus acrodon, Planera Uiige^'i and Fagus feronice could all be matched with leaves from Bournemouth, and so resemble each other that it appears strained to have separated them under three genera and to form two new species from such material. On the other hand, one of the five figures (Fig. 5, pi. 28) ascribed to Ficus lanceolata is quite distinct from the rest and is certainly not that species, but a common British Eocene form. Ficiis multinervis, Heer, is one of our most abundant Eocene plants, and, as suggested by Saporta, is more probably a Laurus. Leaves referred to Ficus oblanceolata, Lesq., analogous to another of our species, might reasonably have been separated as two species. As a group, the leaves called Ficus remind us of those met with in the Eocene. A remarkable feature in the flora is, that but a single form is referred to the Proteacete, and from its cha- racters it seems unnecessary to refer even this to that group. Of the Lauriniae, Launis has an Eocene aspect, whilst the species of Cinnamonum appear correctly iden- tified with Miocene forms. The nine species of Vibtirnum, which would perhaps have been better reduced to two, are analogous to a Bournemouth leaf, but still more so to the Viburnum of Suzanne. A leaf referred to the Australian genus, Caliicoma, is of simple lanceolate form, with serrated edge, whilst two other forms referred to Ericacece are very indistinctly characterised. Many of those named Sapindus and Diospyros, as well as Zizyphus and Rhainttus, are of essentially Eocene facies and very similar to Bournemouth forms. The leaves placed together as Ilex dissimilis are so unlike that it seems doubtful whether they could hare belonged to the same species. The apparent defects which are here pointed out, may be partly due to imperfect figures, and reference to the specimens themselves might uphold the correctness of M. Lesquereux's separate determinations, since the specific identity or otherwise, of leaf forms, is often, after all, very much a matter of individual opinion. The third part of the work contains a tabulated list of all the plants with the relative position of the beds from which they are derived, and also their possible relationship to those of the Eocene and Miocene strata of Europe. This is followed by a careful digest of the matter contained in the work, from which the'follow- ing important facts are to be gathered. The lower group contains 200 out of the 325 species described, and is so isolated that but sixteen of the forms pass into the higher tertiaries, and these include none of the essential types, as the palms, magnolias, Grewiopsis, Viburnum, Rhamnus, &c. The second group has thirty-four species, twenty peculiar to it, and is, on the whole, correlated rather with the overlying Miocene than with the Lower Lignitic. The third group is unhesitatingly pronounced to be Middle Miocene, on account of the relation of its plants to the so-called Miocenes of Alaska, Greenland, Spitz- bergen, and Europe ; and it is further said that no Eocene type is present in the group. The fourth group is also June 20, 1878] NATURE 191 Miocene, and indicates a temperate climate such as that now prevailing in the middle zone of the United States, as from Ohio to North Alabama. The larger number of its species are identified with, or analogous to, those of Greenland, Spitzbergen, and Alaska, whilst a few arc related to Pliocene plants, and three species are still living. Mr. Lesquereux devotes the concluding pages of his ATork to proving the Tertiary age of the Lig^itic series. If, as he states, he has correctly ascertained that, in the first or lowest group, 120 species represent Tertiary, and only six can be considered at all as Cretaceous forms, he has made good his case, and all European palaeontologists will agree with his views as to the age of the Lignitic. The study of a very large series of British Eocene plants in my own collection, from well-defined horizons, has enabled me to draw somewhat different conclusions from those of Lesquereux and Heer. Unfortunately no great and undoubtedly Eocene flora has ever been described or published, and I therefore use the Bournemouth as a typical Eocene flora. The flora of Ceningen, made so familiar to us by Heer, is a typical Miocene flora, and although most unlike a true Eocene flora, contains many plants common to other isolated fragments of strata which contain mixed floras, that is, floras with percentages of Eocene as well as Miocene plants. There being no typical series from the Eocene available as a standard of comparison, the plants common to the Miocene have alone been taken to deter- mine the age of these beds, and the unknown Eocene forms have thus been enrolled as Miocene, and in their turn used to identify other still more distinctly Eocene beds as Miocene ; much in the same way as the Barton beds were formerly identified, from their possessing a few species in common, as London clay, and the species peculiar to the Barton horizon subsequently made use of to identify Calcaire-Grossier and Bracklesham beds in their turn with the London clay. The errors which have thus possibly been committed even by Heer, who has been led to class all the many floras he has so ably described, either as Cretaceous or Ivliocene, were therefore unavoidable, and scarcely reflect upon his judgment. The Lower Lignite is, in my opinion, undoubtedly Eocene, and probably contemporaneous with our London Clay or Lower Bagshot. The sudden incoming of palms and European plants of tropical kinds, and of mammals, and the displacement of the indigenous and temperate flora and of the lingering Dinosavurians, is evidence clear and unmistakable, that the continents became united at this period. Simultaneously with this sudden increase of temperature in America we find a corresponding increase in Europe, as seen on comparing together the faunas of the Thanet Sands and London Clay. The increase was in all probability due to the final rise of a land barrier completely shutting out all the cold northern currents, which at the pre- sent day set towards the equator, and so materially modify the ocean temperature. I think we are thus able to fix the comparative age of the Lower Lignitic, which, being upwards of 2,000 feet thick, probably required a great part of our Middle and Upper Eocene period for its deposition. I regard the second group as of our Upper Eocene age, and the third and fourth groups as Miocene. Now comparing Dicotyledonous leaves of the Lignitic flora with those of Arctic regions, we find several, eren of those from the Lower Lignite, common to both. The greater part of these are included in the following list : — Viburnum Whytnperi, Heer. Fraxinus denticulata, Heer. Diospyros brachysepala, Al. Br. Andromeda Gray ana, H. Cissus tricuspidata, H. Vitis Olriki, H. Ficus iiliccfolia, Al. Br. We find common to the Lower Lignitic and the Mio- cene of Switzerland — Querciis neriifoiia, Al. Br. „ chlorophylla, Ung. „ Godeti, H. Salix angtista, Al. Br. Populus melanaria, H. „ mtitabilis, H. Ficus tilicBfolia, Al. Br. Cinnatnonum Scheuchzeri, H. ,, polymorphttm, Al. Br. Daphnogene anglica, H. Diospyros brachysepala, Al. Br. Cor mis Studeri, H. Berchetnia multinervis, Al. Br. Rhamntts alaiernoides, H. „ rectinervis, H. ,, Rossmdssleri, Ung. or far more than sufficient to have identified the forma- tion with Miocene had its true position not been other- wise ascertainable. None of these are, however, very distinctive leaves, and, with very few exceptions, they might, had the English Eocene Flora been published, have been referred to it with greater approximation to certainty. The exceptions are of little value, C. Scheuch- zeri being identified on half a leaf, while the references to P. muiabilis and C. polymorphum are extremely doubt- ful. The truth is that so many of the ovate and lanceolate leaves of the Miocene and Eocene resemble each other that it would be easy to compile a sufficient list to refer, with plausibility, any given flora to either age, according to the author's fancy. I have not yet had leisure to enter more minutely into the question, but it appears to me that the fact of a proportion of the Lower Lignitic leaves, which are of undoubted Eocene age, being also found in the Arctic floras, and the untrustworthy nature of the evidence on which these have been referred to Miocene, still leaves the question of their true age, on palaeo-botanica evidence, unsettled. We know that in Eocene times these regions were land, and that floras existed upon them, and passed from one continent to the other, whilst in Miocene times, from the decrease in temperature, we infer that the submergence of this bridge had com- menced. Further, the high temperature in the Eocene time would have permitted a temperate flora to grow in these latitudes, and the Miocene temperature would not. Lastly, it is difficult to conceive that the same quality o flora could have grown contemporaneously in latitudes so widely different as the United States and Greenland or Spitzbergen, but there is no difficulty in realising that a decreasing temperature, such as prevailed in the Miocene would hare gradually driven the northern forms south- ward, and thus the very similarity of the Miocene flora of America to that of the Arctic circle renders it unlikely that they were of the same age. J. S. Gardner 192 NATURE \_yune 20, 1878 FOURIER'S ''-ANALYTICAL THEORY OF HEAT'' The Analytical Theory of Heat. J. Fourier. Translated by A. Freeman. (University Press, Cambridge, 1878.) THERE cannot be two opinions as to the value and importance of the Theorie de la Chaleur. It has been called "an exquisite mathematical poem," not once but many times, independently, by mathematicians of different schools. Many of the very greatest of modern mathematicians regard it, justly, as the key which first opened to them the treasure-house of mathematical physics. It is still the text-book of Heat Conduction, and there seems little present prospect of its being superseded, though it is already more than half a century old. It contains the first satisfactory definition of Conductivity, the first statement of the dimensions of various physical -quantities, and the invaluable expression for periodic quan- tities in terms of harmonics. Many important problems of heat conduction are completely solved, and the results are given so as to be immediately applicable in practice, as for instance to the cooling of spheres (including the secular cooling of the earth) the propagation of periodic changes of temperature into the crust of the earth, &c. But the heat equations are of the same form as those in certain other branches of physics. Here they are solved once for all, and form a store from which all may freely help themselves. Thus, a very minute fragment of the work sufficed, by its application to electric currents, to render the name of Ohm famous. More important portions have been applied to Diffusion, to Signalling through Submarine Cables, and to various other im- portant questions. With all its transcendent excellences this great work had two faults at first, and of late it had acquired a third, (i.) It was a little prolix. Like Ampere's great work, . and some others of that wonderfully fertile period, it was made up as a sort of patchwork of memoirs sent to the French Institute. Each memoir was, as it were, com- plete in itself : and the putting together into one work, without judicious paring down, necessarily involved a good deal of repetition. (2.) It was so full of printers' blunders and mere slips of the pen that it must have been very carelessly revised. (3.) It had become very scarce, and consequently expensive. The Syndics of the Pitt Press deserve great credit for reproducing the book : — and the printers have done their share of the work well. Still, the result can hardly be , called satisfactory. For this there are many reasons. (i.) We think it was a great mistake to translate the book into English. The poetry, except so far as it was in the formulae, is gone ; and the prolixity, which was toler- able in the original, is painful in the translation. The text should have been considerably compressed in translation, or else simply reproduced in French. Every one who has any right to read Fourier reads French, or at least ought to be able to do so. Again, though Conducibilite and Conductibilite are good French, Conductibility (being altogether erroneous) has hitherto been confined to the jowest class of English books. Conducibility, which Mr. Freeman most commonly employs, is not an English word at all ; ^ and, even if it were, could not possibly mean Conducting power, or Conductivity. (2.) We have compared at least one whole chapter with our own annotated copy of the original. Roughly speaking, only about 50 per cent, of the misprints in the original have been corrected. The others, some very misleading, are reproduced. The worst of those we have noticed are at pp. 124 [Eq". {a)\ 134, 189, 226. In p. 181 an erroneous reference is reproduced, and in order to make it fit the text the reference mark is shifted from the general equation (really referred to) to a mere particular example. (3.) The translator has added a few notes, some by the late Leslie Ellis. But they are very fragmentary. Surely more than a single sentence might have been devoted to the experimental results of Forbes [and Angstrom] ; Stokes and Duhamel ought to have been mentioned with reference to conduction in non-isotropic solids — and Thomson's proof that Fourier's solution of the problem of the cooling sphere is complete deserves much more than the mere casual mention it has received. OUR BOOK SHELF Anthropology. By Dr. Paul Topinard, with a Preface by Prof. Paul Broca, translated by Dr. R. Bartley. (London : Chapman and Hall, 1878.) This volume forms another of the Library of Contem- porary Science, and it purports to elucidate a science which is well described by Paul Broca as being one of vast dimensions and one in process of rapid develop- ment, as well as one which has hitherto not received sufficient attention. The masters of the science en- gaged in original research naturally shrink from the labour of writing a handbook of a popular charac- ter : and it fell to Dr. Topinard's lot to make the attempt — in which attempt he seems pretty fairly to have succeeded. This work falls into three sections : the first treats of the physical characters of man, and of his place in nature. The chief human anatomical peculiarities are briefly alluded to, with a somewhat need- less— to our mind — reiteration of the assertion that the organisation of anthropoids is a counterpart of that of man, and differs widely from that of the other Simian groups. The second section treats of the races of man- kind ; and here we have a great many important and interesting facts marshalled in fair order before us. A few more woodcuts would have been an improvement to this portion. In the concluding section the origin of man is discussed ; and the author passes in array the monogenestic theory of Quatrefages, the polygenestic theory of L. Agassiz, the transformation theory of Lamarck, and the natural selection theory of Darwin, and works out in detail the application of each to man and his genealogy. The translation, which is generally good, might, however, in places be improved, and it is sometimes a little confused. I On reference to Richardson we find one instance of the use of the word, by (Bishop ?) Wilkins. We freely give Mr. Freeman any benefit which he can extract from the following passage : — " Duties deriving their obligation from their conducibility to the promoting of ends. " It may interest readers of Nature to be told that, in looklne; for the word in the Supplement to the Imperial Dictionary, we found the followingextra- ordinary statement (illustrated by a diagram) about Conjugate Foci :— " when rays, falling upon a lens, are so refracted as to converge and meet in a point, either nearer the lens than the principal focus, or farther from it, the point in which they meet, and the principal focus, are called, with respect to each ether. Conjugate Foci." Jtme 20, 1878] NATURE 193 The Tailed Amphibians, hicluding the Ccecilia?is. A Thesis presented to the Faculty of Michigan University by W. H. Smith. (Detroit, Michigan, 1877.) The title of this little volume tells its ovm story. It is a detailed catalogue of all the species of tailed amphibia known. In addition to using the works of all the best writers on this group, Mr. Smith has availed himself of the specimens in his University Museum, and from these has drawn up many of the descriptions and characters. A number of artificial keys are given to the genera and species ; the synonymic lists appear to have been worked out with care, and to have been brought down to date. A list of authors on the subject of the work is appended, and here and there, after the diagnoses of the species, will be found details of their habits, geographical distribution, and development. LETTERS TO THE EDITOR [TTie Editor does not hold himself responsible for of inions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of rejected manuscripts. No notice is taken of anonymous communications. [The Editor urgently requests correspondents to keep their letters at short as possible. The pressure on his space is so great that it is impossible otherwise to ensure the appearance even of com' munications containing interesting and novel facts.l Indian Rainfall Agreeing in the main with the views put forward by Mr Archibald in his letter in Nature (vol. xvii. p. 505), I beg leave to refer briefly to one or two points in which I differ from him, and I hope that you will be able to find space for this note, because Mr. Archibald has done me the honour of mentioning my name so frequently in his letter, that I might reasonably be supposed to entertain opinions identical with his own on all points regarding the question under discussion. In the first place I would point out that the atmospheric cur- rent which brings the winter rains of Northern India, whilst it has nothing to do with the summer monsoon, does not descend in the Punjab, as Mr. Archibald says, and then proceed east- wards to the North- West Provinces and Behar, and sometimes even as far as Calcutta, but blows in just the opposite direction, appearing as a south-east wind over the Gangetic plain and the Eastern Punjab. The place of its descent in the winter months is farther south, in latitude 22° or 23° N., and thence it flows northwards in almost the same manner as the summer monsoon. In the next place, I think the hypothesis of the approxi- mately inverse variation of the winter rain, as compared with sun-spots, does not necessarily postulate a corresponding inverse variation of solar radiation. Such a relation I consider to be highly probable, but the somewhat meagre data I was able in a former communication (vol. xvi. p. 505^) to adduce in favour of it were only intended to prove that the question of "solar activity " was yet an open one, and that it did not follow that solar radiation was most intense at times of maximum sun-spots, because many meteorologists, reasoning from magnetic and other analogies, assumed it to be so. The direct solution of the ques- tion must be accomplished by actinometric observations, as Mr. Blanford proposes, and, while it remains unsettled, it will pro- bably be best to try and correlate the variations of rainfall with those of some other meteorological element upon which rainfall depends. I have recently been occupied with an analysis of the rainfall observations of twenty stations in Northern India, embrac- ing between them ii* of latitude and 24° of longitude, and extend- ing over periods of from fifteen to forty-nine years, and I find a remarkable coincidence between the variations of the winter rainfall and those of the temperature of the tropics as given by Koppen in his exhaustive paper in the Zeitschrift der oestcr- reichischen Gesellschaft fiir Meteorologie, vol. viii., Nos. 16 and 17. When the rainfall deviations of the different stations are thrown into the form of percentage variations from the local mean and are then combined and the results " bloxamed," we get a series of numbers which gives a curve from 1834 to 1877 resembling Koppen's curve very closely, when the latter is extended up to 1877. The two curves not only resemble each other in all their more important fluctnations, but their epochs of maximum and minimum approximately coincide. These are : — Mpv \ Tropical Temperature 18427, 18547, 1865-1, 1876-3 (?) • 1 Winter Rain 18427, 1855-0, 1865-5, i876-9(?) ,,. f Tropical Temperatiure 1836-9, 1847-7, 1858-4, 1874-8 ''""• t Winter Rain 1837-8,1848-1,1860-6,1874-7 It would therefore appear to be highly probable that the periodic variation of the winter rainfall of Northern India is caused by a corresponding variation in the temperature of the tropics, which determines, within certain limits, the quantity of vapoiur added to the air and the direction and velocity of the atmospheric currents. It appears, also, from the table, that the maxi- mum of winter rainfall is attained nearly a year before the minimum epoch of sun-spots, as given by Wolf, I have found that this is also the case with the winter rainfall of London, and Mr. Draper has shown (Nature, vol. xvii. p. 16) that the sam.e relation holds good at New York. The co-existence of severe droughts in Hindustan with devas- tating floods in Burmah and Assam, is a very strong argument against the theory of Dr. Meldram that the rainfall of the whole globe varies directly with the sun-spots ; but it would naturally follow from the view advocated by Mr. Archibald, becau!:e, in very hot years, which are approximately those of minimum sun- spot, the general tendency to a cyclonic circulation of the atmo- sphere round the Asiatic continent in the summer months would be so intensified as partially to obliterate the smaller cyclonic indraught towards Central India, which brings up a moist current from the Bay of Bengal to the Himalaya and the plains of Northern India. S. A. HiLL Allahabad, May 18 A Twenty Years' Error in the Geography of Australia In almost every detailed map of Australia, including some of the latest, we find, at the head of the Alligator River, in about S. lat. 135°, and E. long. 133°, some such note as this : — " Steep walls, 3,800 ft." This is copied from the map illus- tradng "Leichardt's Journal," published in London in 1847. This map was (as stated in the preface) drawn by S. A. Perry,- Esq., Deputy Siurveyor-General of New South Wales, from materials furnished by Leichardt, and was engraved in London by Arrowsmith. As Leichardt only returned from his first expedition at the end of 1845 or beginning of 1846 he could have had no opportunity of correcting or revising this map. Mr. James Wilson, the geologist to the North Australian Ex- pedition under Mr. A. C. Gregory, having passed over much of the same country, and finding the plateau nowhere more than 1,600 feet above the sea, came to the conclusion that Leichardt's supposed statement was an engraver's or printer's error which had escaped correction, and gave his reasons for this view in the Proceedings of the Royal Geographical Society, vol. i. p.- 230, and subsequently in the same society's Journal, vol. xxviii. p. 137 (1858). Notwithstanding the extreme impro- bability— almost amounting to absiurdity — of there being pre- cipices of the enormous height of 3,800 feet, in a country where there were no important mountains, and where Gregory,, who had passed within eighty miles, and M'Douall Stuart, who had passed within forty miles of the place, found nothing but a moderately-elevated plateau, with ravines never exceed- ing 600 feet deep, no notice appears to have been taken of Mr. Wilson's correction, but the "3,800 ft." has been copied again and again in works of reputation and authority. We find it even in the new edition of the " Encyclopa;dia Britannica,"art. " Aus- tralia," given as an e^.tablished fact in the following words : — " On the north side of the continent, except around the Gulf of Carpentaria, the edge of the sandstone table-land has a great elevation ; it is cut by the Alligator River into gorges 3,800 ft. deep." The curious 'thing is, however, that this marvellous pheno- menon, which, if it existed, would be unapproached in Australia and equalled nowhere but among the mountains of the great continents, is not even alluded to in the published journal of the traveller who is supposed to have discovered it ! On Leichardt's map the "steep walls" are noted between the stations of November 10 and 11, but in his "Journal" we find no reference to anything remarkable till November 17, when he comes to the head of a magnificent valley, into which he was obliged to descend, and which caused him much delay and circuitous- explorations en account of its steep rocky waUs estimated by him to be " i,8co feet high." It is pretty clear, then, that the 194 NATURE {June 20, 1878 " 3, 800 feet " is a map error, and that even the 1,800 feet is merely an estimate, and probably an over estimate ; for we must take into consideration the evidence of other explorers in the same region, and the appalling effects of coming, in a nearly level plateau, to the brink of such a precipitous rocky barrier. I am making a similar correction to the above by means of a note in a work I am now engaged upon (on Australian Geo- graphy), but as the error has obtained such wide circulation and seems so hard to kill, it becomes advisable to call attention to it as soon as possible, and in a way that will be likely to attract attention. Alfred R. Wallace Opening of Museums on Sundays Your last number contains a letter from my friend Prof Corfield, which I confess to having read with some little astonish- ment. He expatiates, and with justice, on the merits of the town of Maidstone, whose citizens do not scorn the grace which " palseontological, conchological, and other collections" must add to life spent in a country "well worth visiting," and who appropriately find their last resting-place in a cemetery " which is one of the most beautiful in the country." I would not demur a moment to such a fascinating picture, were it not that Prof. Corfield, led away by a pardonable enthusiasm, expresses his belief " that this is the first and only scientific museum that has yet been opened on Sunday in the United Kmgdom." Surely the Chairman of the Committee of the Sunday Society need not go to Maidstone for the first victory in the very just cause which he upholds, seeing that for the last quarter of a century the three buildings which contain the Botanical Museum of the Royal Gardens, Kew, have been open to the public from two till dusk every Sunday throughout the year. Royal Gardens, Kew W. T. Thiselton Dyer The Telephone Relay or Repeater The WTiters have been at work since the announcement of the invention of the Bell articulating telephone in endeavouring to devise means by which the telephone might be relayed. Quite a number of devices have been tried, but, from the exceedingly feeble amount of the movements]of the diaphragm'of the receiving telephone, they have heretofore' been unsuccessftd in obtaining any practical results. The discovery by Prof. Hughes of the inexpressibly delicate microphone has given us the means by which we have finally at last solved this very important problem. We apply the micro- phone as a telephone relay or repeater by attaching it directly to the diaphragm of the receiving telephone. The microphone so attached is a miniature one consisting essentially of three pieces of carbon, arranged as described by Prof. "-Hughes. The two parallel pieces are cemented directly to the telephone diaphragm, and the third piece placed in cavities near their ends. The microphone forms, of course, part of the new circuit in which it is desired to repeat the telephonic message. By the movements of the telephone diaphragm the microphone produces such variations in the electrical current traversing its circuit as to cause the original message to be repeated to any instruments placed therein. We have tried our telephone relay or repeater on several tele- phone lines, and find it to work satisfactorily. By attaching a number of miniature microphones to the receiving diaphragm and suitably connecting the battery, increased delicacy will un- doubtedly be obtained. Edwin J. Houston Central High School, Philadelphia, Elihu Thomson U.S., June 7 Socialism in South Africa I noticed this morning that along the bottom of the front wall of my house, on the verandah, there lay a quantity of red- dish-brown powder ; there was enough to fill a coffee-cup. On looking closer I saw that it was made up of small and larger frag- ments which glistened, and on inspecting some in my hand they turned out to be the heads, legs, trunks, &c., of countless ants. A number of these animals were still on the wall above, and my attention being now arrested, I watched them, and saw that they were contributing to the carnage beneath. This species of ant is a small, comparatively harmless one, the chief sin of which is that it makes its way to every species of food and swarms on it. As is usual with ants, the general body of insects is accompanied by larger individuals, which are provided with heads and jaws quite disproportionate to their bodies, and with these jaws they do all the cutting up. Among the ants on the wall there was a large sprinkling of these "soldier ants," and the whole commu- nity seemed to be bent on destroying them. The proportion of heavy-jawed to ordinary ants was about one to ten. I saw a group of little ones fastening on to a big one, which made despe- rate efforts to release itself. At first the big one bit several little ones in two, and the parts dropped down from the wall ; but after a while the little ones severed all the legs of the big one, and finally got on his back and cut him in two. The group then dropped down to swell the mass below. Similar scenes were enacted elsewhere on the wall. The commencement of one combat was as follows : — A big ant walked along till it met another big one, and the two shook antennae. Just then a little one seized hold of a hind leg of one of these big ones. Neither took any notice, but continued a rapid conversation. Su Idenly other small ones came up, when the big one whose leg was grabbed turned furiously on the little one and seized him by the middle. This could not be done until the big one had doubled himself up ; as soon as he had hold of his small antagonist he lifted him in the air and snipped him in two. Meanwhile all the big one's legs had been seized by little ones, and the party seemed to turn over and over, little bits tumbling down, now a leg, now half an ant, till the big one was vanquished. The ant is most assuredly subject to passions. The way in which the big ant turned on the little one was singularly indica- tive of rage. The determined manner in which he laid hold of the little one was quite human. If I had had a magnifying glass, the scene would have been really exciting. Maritzburg, Natal, May 12 F. E. CoLENSO New Form of Microphone Receiving-Instrument Having been experimenting with the microphone, and study- ing the effect of the passage of the current on a galvanometer, it occurred to me that if the needles were fixed, strains would be produced in it by the action of the current. To test this, T passed a few yards of copper wire (about No. 30) on a small bar magnet lengthwise, and found, on placing it to the ear, that sounds were heard on interrupting the current ; these sounds were much intensified by placing the magnet inside the lid of a pasteboard box. Having a six-inch horse-shoe magnet beside 'me, I passed along one of its limbs from two to three yards of the same wire, and on placing the lid of a tin box on the flat sides of the ends of the magnet, an excellent receiving-instrument was obtained. With this tuning-fork, sounds, singing, whistling, speaking, and violin miisic were heard distinctly. A single Leclanche coil was used, the transmitter consisting of two small pieces of carbon pencil touching slightly, and connected with an open pasteboard box. W. J. Millar Glasgow, June 17 A Waterspout Among the meteoric phenomena of which we have heard recently, not the least interesting occurred on Thursday the 14th near the Kelston Round Hill, about three miles to the west of Bath. Shortly after five o'clock in the evening the inhabi- tants of the village of Weston, which lies between Kelston Hill and Bath, were startled by a volume of water advancing like a tidal wave along the Kelston Road ; in a minute the water was upon them, flooding the houses and laying the main street four feet deep under water ; with such force did it come that a stone weighing five hundred-weight was carried several yards, while smaller ones were taken a much greater distance. It was not known in the village from where the water had come, but it so happened that about five o'clock I was proceed- ing to Weston Station by the Midland Railway from Bristol to Bath, and when in sight of the Round Hill I was struck by the blackness and lowness of the clouds in its vicinity. Suddenly there was a flash of lightning, and immediately after the Hill was enveloped in what appeared to be a storm of rain of unusual density. On arriving home I was not altogether surprised to find the commotion in the village, and I at once attributed the source of the water to the cloud which I had seen ; I therefore made my way in the direction of Kelston Hill. On arriving under the brow of the Hill it was very clear that something more than an ordinary storm had occurred. Near the June 20, 1878] NATURE 195 end of a lane (Northbrook) leading to some fields, the hedge on the right for some yards was lying in the road, but the field beyond at this point presented only the appearance of an ordi- nary storm, while the lane itself was like the bed of a river. To the left was a field of standing grass ; for about twelve feet from the hedge the grass remained intact, then for about the same distance it was as though it had been mown down. This torrent, for such it might have been compared to, came to almost a £udden termination a little above the end of the lane, but it extended down the Hill till it was joined by two others, one of which had carried a hedge away bodily. The increased volume of w ater then poured down over some gardens, uprooting trees and vegetables ; in less than ten minutes the hedges were lost sight of, and the water rose to a height of eight feet. This was occasioned by a block caused by an arch, which carried off the water from a small stream, not being large enough to take the increased volume. Finally it burst over, scooping the ground out in front of some cottages several feet deep and flowed on as a river some yards wide, again destroying gardens in which were valuable stocks of vegetables. Near this point the volume of water was again increased ; in all five distinct water-courses could be made out, all of which had done considerable damage to grass, cornfield^, and gardens. Finally, all united in one body and poured into the village of Weston, levelling three walls as it came, and thence passed into the river Avon. I gather from spectators at Kelston Hill that it began to be cloudy at half-past four in the afternoon ; at five there was a rattling clap of thunder, followed by a downpour of rain — in "bucket-fulls," as one expressed it; but all seemed to agree that the greater portion of the water fell under the brow of the hill, where it came down in several columns. There were no houses close to the spot ; had there been they must have been washed away. The atmosphere had been perfectly still all day, but very sultry. Heavy rain fell in the neighbourhood, and the storm to which I have referred specially was accompanied with hail, which in a few minutes covered the ground some inches deep. What I have described is no doubt what is popularly termetl a waterspout. The damage done was at first estimated at 2,oco/., but it is. now feared that this amount will not cover it. Weston, near Bath, June 17 E. Wethered Fortunate "Escape" An evening paper of to-day's date has the following : — "house struck by lightning. " During the thunderstorm yesterday, at about 2.30 p.m., a large stack of chimneys at the residence of Mr. Robert Avis, at Putney, was stnick by lightning, which split the chimney-shaft down the whole height, the electric current passing down the chimney and into a sitting-room on the ground floor. Tke dcor of the room was fortunately open, and the current escaped tinthout causing injury to the family, who were in the room at the time of the shock." The italics are those of one Electrified June 17 Velocity of Light ^yILL ycu have the kindness to publish the following as a preliminary announcement : — The following method of measuring the velocity of light dispenses with Foucault's concave reflector, and permits the use of any distance. In the figure, j is a division of a scale ruled on glass ; m, a . revolving mirror, /, an achromatic lens ; /', a fixed plane mirror' at any distance from /. The point j is so situated that its image s reflected in the mirror m is in one of the foci of the lens /, while the image of s' coincides at /' with the mirror, the latter being placed at the conjugate focus. With this arrangement, when m turns slowly, the light from /' is reflected back through the lens, so that an image is formed which coincides with s. When, however, the mirror rotates rapidly, the position of m will have changed while the light travels from m to /', and back again, so that the image is displaced from s in the direction of rotation of the mirror. Let Fbe the velocity of light ; D, twice the distance m s' ; n. the number of turns per second, and r the distance vi s ; then, calling 5 the deflection, Vis found from the formula — rr _ ^Tf rn D 5 In a preliminary experiment the deflection amounted to five millimetres when the mirror revolved 128 times per second. The following is another plan which would probably giye*^ more light than the above. - .'., s is as before the image of the scale reflected in tb^ mirror JfWj^J^ its image would be formed at i" by the lens /, and the image of y would be formed at /", where the plane mirror is placed. In this case also, the rays are reflected back, so that the scale and its image coincide notwithstanding the (slow) rotation; of m. Albert A. Michelson U.S. Naval Academy, Annapolis, Mar}- land University College The fiftieth anniversary of the opening of University College falls within this year. It is intended to celebrate the occasion by a gathering of members of the corporation, present and past, professors and masters, old students of the college and school, and other friends and benefactors of the institution, to be held within the precincts of the college, on Tuesday, July 9, at I o'clock P.M. The Right Hon. Earl Granville, K.G., Chancel- cr of the University of London, has kindly accepted the invita- tion of the President, Council, and Senate to attend and lay the first stone of a further extension of the college buildings and preside at the luncheon ; and the presence is expected of many other persons of distinction interested in the welfare of the col- lege and in the promotion of University education. The space at the disposal of the coUege, even since the school has been entirely withdrawn to the south wing, is far from ade- quate to the rapidly increasing requirements of modern educa- tion. The Fine Art Department has been obliged to refuse pupils. The Council ha--, moreover, after prolonged experience 196 NATURE \^yune 20, 1878 of the satisfactory working of the Ladies' Educational Associa- tion, recently decided to open the Faculties of Arts and Law and of Science to women. Again, there is a very general demand for increased facilities 'of instruction in engineering and other branches of applied science, which ca'n nowhere be so efficiently met as in connection with a flourishing scientific school like that of University College, Lastly, the numbers of the school have for some years been steadily increasing, and it is not luireasonable to hope that it may soon outgrow its present space. On all these grounds an urgent necessity is now imposed upon the college to undertake a considerable enlargement of its buildings. Application for tickets should be made to the Jubilee Celebra- tion Committee as early as possible. Talfourd Ely, University College, London, June 18 Secretary Examination of Small Organisms in Water In order to examine the minute organisms that inhabit water, such as rotifers, vorticellae, and kindred microzoons, the arrange- ment I proposed some years ago in the Quart, yourn. of Micros. Set. will, I believe, be found most convenient. This is to inclose the objective in a brass or other metal tube having its lower end closed by a piece of thin microscopic glass coming close up to but not touching the object-glass. With this protection we can plunge the end of the microscope into a small tank, filled with water, containing the small living organisms, and examine them at our leisure for days or even weeks. The thin glass plate im- mersed in the water gives us a perfectly steady, flat water- surface, which is not disturbed by any agitation of the surface- water of the tank. Objectives of an inch, half an inch, a quarter of an inch, and even an eighth of an inch focus, may be thus used under water, and all the trouble of catching and ensnaring the small animals is thus avoided. This invention I first employed for the examination of morbid secretions, such as urine. I have since employed it for watching the operations of minute creatures thaf inhabit water, which may thus be seen in their natural habitat and under normal conditions, which is not the case when they are seen in the usual way, between the two layers of glass on an ordinary microscopic slide. Any optician can make such a tube to screw over the objective of any micro- scope, and, though it can readily be removed and applied, its presence does not interfere with the use of the microscope in air. 53, Montagu Square, W. R. E. Dudgeon THE LATE MR. HEW ITS ON ■nrHE memory of the warm-hearted gentleman above- ^ named deserves a passing notice in these columns, for the effect of his labours on at least one department of natural history has been great. William Chapman Hewitson, who died at Oatlands, near Walton-on-Thames, -on May 28 last, aged seventy-two years, was by birth a Northumbrian, and, after the somewhat rough education of a Westmoreland school, took up the calling of a sur- veyor. His passion for natural history was exhibited in very early life, and, after some years' practice of his profession, the fortunate inheritance of a competence, and something more, from an uncle saved him the neces- sity of pursuing a distasteful vocation, and enabled him to indulge his fancy practically without stint. In 1831, while still engaged in his professional duties, he projected his '' British Oology," the first part of which appeared in April, 1 83 1, and the last in 1838. As he himself subse- quently wrote : — " The book was itself as migratory as the birds, the eggs of which are depicted in its pages ; many of the plates were drawn at night after a long day of railway surveying in the fields, and the letter-press was printed \yherever the author happened to be stationed at the time. There were few collectors to aid him in those days, and it is with a grateful feeling he remembers now the helping hand which was then held out to him by his friend Mr. Yarrell." Yet the work was a great success. Such beautiful figures of eggs- all drawn on stone by the author- had never before been seen, for his touch was as delicate as his eye was correct, and great care was bestowed upon the colouring. His zeal for the task he had undertaken, led him with two friends, one of whom was Mr. John Hancock — perhaps the best ornithologist now living — to visit Norway and explore its coasts in quest of those many British birds, of the nidification of which nothing was known except that it was not carried on in these is- lands. This expedition in 1833 to a country hitherto so little explored by Englishmen as Norway, was no small proof of enterprise, and, with the simultaneous attempt, with a like intent, made in Iceland by Mr. G. C. Atkinson, bore good fruit, not merely in its immediate results, but even long afterwards ; for it was doubtless the example of these gentlemen^ that prompted the subsequent exertions of Wolley, Hudleston, Salrin, Tristram, and others ; while the successes in recent years of Alston, Harvie Brown, Danford, and Seebohm, may also be traced to the same cause. The influence has even extended to the United States, as witness the explorations conducted by Kennicott, Macfarlane, and their indefatigable successors under the authority of the Smithsonian Institution. The result has been that the true home of almost every species of bird which inhabits Europe at any time of the year has been discovered, and the same with a large number of those which inhabit North America, and thus, of course, has accrued a great gain to ornithology. Mr. Hewitson, however, did not pretend to foresee this sequel to his enterprise and that of his friends. His aim was far humbler. In his own words : — " However unimportant in itself the branch of natural history which I have attempted to elucidate, the beautiful and varied objects which compose it are amongst the first to excite the imagination and call forth in boyhood those feelings, that love for nature, which are inherent in us all ; and however the cares or the pleasures of after life may have erased those earlier feelings, there are few who have not one day derived pleasurable emotions from their contemplation, and who do not remember those joyous times when, at the first breaking loose from school, they have hastened to the wood and the hedge- row in search of their painted prize." The "British Oology" was soon out of print and a second edition was called for, which, under the title of " Coloured Illustrations of the Eggs of British Birds," was begun in 1842 (when the author took the opportunity of publishing a Supplement to his former issue) and finished in 1846, while in 1853 — only eleven years later — a third edition was demanded. This, completed in 1856, remains unquestionably the best publication on the sub- ject ; for, though the plates were not so carefully coloured as in the second edition, the number of species repre- sented, chiefly owing to the discoveries of Wolley, was largely increased. But in the meanwhile Hewitson's taste had turned towards another department. He had begun with his usual energy that wonderful collection of diurnal Lepidoptera, and v/orks in illustration of that group, with which his name will be always associated, and by which it will probably be most widely known. His villa at Oatlands, with its beautiful view and charm- ing garden, was a sight not to be forgotten, to say nothing of the glorious contents of his cabinets. Here he passed the last twenty-five years of his life, or more ; seldom leaving home, always glad to welcome a visitor whose tastes agreed with his own, and occasionally re- turning to his old " flame," when he could thereby assist a friend — as witness some of the plates in the earlier volumes of The Ibis. The promulgation and subsequent prevalence of the doctrines of evolution, however, greatly disturbed him ; and perhaps the only thing that ruffled his temper was to hear that one naturalist after another had embraced what to him seemed a pestilent heresy. ^ It is fair to mention that in 1830 Hoy began a series of tours into the Netherlands with the same object, and in 1831 Salmon made an egg-collecting voyage to Orkney and Shetland, but the places they visited bore no com- parison in remoteness and difficulty of travelling to those above-mentioned. June 20, 1878] NATURE 197 So firmly did he stand on the ancient ways that he has been often heard to say — and he may have even expressed the sentiment in as many words in some of his writings — that he could not look into one of his insect-drawers without disgust did he not believe in the direct and independent creation of each individual species. At any rate he never lost an opportunity of avowing his hatred of Darwinism, though his opposition to it made no difference in his feelings towards those of his friends who were Dar- winians. It is understood that before his death he had ar- ranged for the ultimate transfer of his magnificent col- lection of Butterflies to the British Museum, where, according to the terms of the compact, its present condi- tion is to remain undisturbed for twenty years. Mr. Hewitson, who was buried at Walton-on-Thames, had been a widower for many years and left no children. A portion of his very considerable fortune he is said to have devoted to charitable purposes, but a large portion of the remainder to his old and tried friend, Mr. John Hancock, while his copyrights go to his publisher, Mr. Van Voorst. It is believed also that Mr. Kirby is to make a catalogue of the collection of Lepidopte7-a before it is removed to the British Museum. A. N. ANDREAS VON ETTINGSHAUSEN \ XT'E regret to record the death in Vienna, on May 25, ' ' of Baron von Ettingshausen, one of the oldest of European physicists. He was born in Heidelberg, November 25, 1796. After the completion of his acade- mic studies, he entered the philosophical faculty of the Vienna University as privat-docent for physics and mathematics in 1817. Two years later he accepted the professorship of physics in Innsbruck, but was called back in 1821 to Vienna, to the chair of mathematics, which position he exchanged in 1834 for the professor- ship of physics. In 1852 he accepted the direction of the newly-grounded Physical Institute, completed its organisation, and raised it to its prominent position as a centre of physical investigation. Some years since he was compelled by increasing age to retire from the duties of his professorship, after a half-century of unwearied activity. As an investigator Ettingshausen was first known by his mathematical contributions. In 1834 he was one of the first to apply Faraday's discovery of electric induc- tion ; and the magneto-electric machine devised by him at this time, and bearing his name, marks an important step in the progress of this branch of physics. Of his later researches we would mention those on the move- ments in homogeneous systems of molecules, on the parallelogram of forces, on the law of isochronism in the vibrations of the pendulum, and on the formulae for the intensities of reflected and refracted light, in all of which the mathematical element Avas predominant. Ettingshausen' s literary work was confined chiefly to his "Vorlesungen iiber hohere Mathematik," which ap- peared in 1827; his " Lehrbuch der Physik," published in 1844, and to the editorship of the "Zeitschrift fiir Physick und Mathematik," from 1826-1832. As a lecturer Ettingshausen was one of the leading celebrities of the Austrian capital. His auditorium was thronged not only by the students but by the educated classes of Vienna, who were attracted by his rare com- bination of oratorical power and experimental elegance. In the Physical Institute he rendered services of the greatest value. For a number of years Vienna was un- excelled in the opportunities it offered to young physicists, and the present activity in physical research existing throughout the Austrian universities is undoubtedly due in a great measure to the healthful impulse given by Ettingshausen a score of years since. It is probably to the same source that we can trace the marked mathe- matical character of the modern school of Austrian physicists, nearly all of whom have been trained under his eye. Ettingshausen' s varied services made him the recipient of numerous decorations, and some years since he was raised by the Emperor into the nobility. He was a leading member of the Vienna Academy of Sciences, which he assisted to found, and for a long series of years its general secretary. His researches appeared chiefly in its Sitzungsberichte. He leaves behind him a son, Baron Constantine v. Ettingshausen, the well-known authority on palaeontology. A NEW CRATER ON THE LUNAR SURFACE "VITHEN examining the surface of the moon on May 27, * * 1877, Dr. Hermann J. Klein, of Koln, observed, with his 5^-inch dialyte by Plossl, a great black crater on the Mare Vaporum, and a little to the north-west of the well-known crater Hyginus. He describes the crater as being nearly as large as Hyginus, or about three miles in diameter, and, being deep and full of shadow, and as form- ing a conspicuous object on the dark grey Mare Vaporum. Having frequently observed this region during the last twelve years, Dr. Klein felt certain that no such crater existed in thisregion at the time of his previous observations. Dr. Klein communicated his observations to Dr. Schmidt, of Athens, the veteran selenographer, who assured him that this crater was absent from all his numerous drawings of this part of the lunar surface ; neither is it shown by Schroter, Lohrmann, nor Madler, who carefully drew this region with the fine refractor at Dorpat. On one or two subsequent occasions Dr. Klein obtained further observa- tions of this new crater. He found it to be either without a wall or with a very low one, but to be a deep conical depression in the surface. Shortly after sunrise the crater takes the appearance of a dark grey spot, with an ill- defined edge. In April, 1878, Dr. Klein communicated his observa- tions to the editor of the Selenographical Journal, who at once took the proper steps to have this object observed by the members of the Selenographical Society. The day for observing this region was unfortunately cloudy, and no observations could be made in England, but Mr. J. Ward, of Belfast, caught a glimpse of the moon through a temporary break in the clouds. He at once saw the crater in the position assigned to it by Dr. Klein, and described it as being a black crater with a soft edge. The next opportunity for observing this crater was May 9, but the occasion was not favourable, the sun being then high above the horizon of this part of the moon. The day turned out cloudy. Messrs. Backhouse and Neison observed through thin clouds, and saw in the position of the new crater a dark elliptical spot. On May 11 Messrs. Knott, Neison, and Sadler observed in this place a dark ovoid mark or shading. So far, then, the English obser- vations have been perfectly in accord with those of Dr. Klein, although bad weather has rendered it impossible to see the new crater as a crater. Mr. Neison repeatedly examined and drew this portion of tlie lunar surface during the years 1 871- 1875, ^.nd dis- covered a number of minute details in the region where Dr. Klein has seen the new crater. Quite close to this object are a number of much smaller craters, several under a mile in diameter. Several of these are shown by Schroter, Lohrmann, Madler, and Schmidt. It may be regarded, therefore, as absolutely certain, that previous to 1876 there did not exist on this portion of the lunar sur- face a deep black crater of three miles in diameter, and it is thus Dr. Klein describes the new object seen by him. Mr. Neison has expressed the opinion that it is most im- probable that he could have missed seeing so conspicuous an object as the present dark marking which it is certain exists now in this region. If, therefore, the existence of 1 98 NATURE {Jime 20, 1878 Dr. Klein's new crater be confirmed, it will form the strongest possible evidence of a real change on the surface of the moon, a change, moreover, of a volcanic nature. The I>I.;rc '''nporum in which the new crater is situated lifes close to the centre of the visible surface of the moon, '■So that objects in this region are very slightly affected by "the lunar librations. Fortunately it is a portion of the surface which has been most carefully studied by Lohr- mann, Madler, Schmidt, and Neison ; for had this new crater of Dr. Klein appeared in a less well-known region, much doubt would have been felt as to whether it had previously existed or not. DEEP-SEA DREDGING OFF THE GULF OF MEXICO 'X'HE last number of the Bulletin of the Museum of -*• Comparative Zoology at Harvard College, Cam- bridge, Mass., contains a letter from Alex. Agassiz to the superintendent of the United States Coast Survey, detailing the results of some recent dredging operations in the United States schooner Blake. A series of deep-sea dredgings were made in the first place across the Florida Channel from Havana to Sand Key, out to the Tortugas reefs, then across the Gulf to the Yucatan Bank, to Vera Cruz, about the Alacran reef and then across the Yucatan Channel, and in the trough of the Gulf Stream to Sand Key, Florida — in all about 1,100 miles of lines taking the shortest distance from point to point. The results of the cruise are full of interest; we can only allude to a few of them. The great Alacran reef is an atol — an atol existing not as Darwin suggests to be the case with atols in general, in an area of depression, but in one of elevation, like those in which the Florida and Bahamas reefs are found. The formation of the Alacran reef is in full activity, the eastern slope is nearly perpendicular, rising to a height of twenty fathoms from the surface in a comparatively short distance. It is exposed to the full force of the north-east trades and the surf breaks heavily against the great masses of Madrepora palmaia,yi\v\ch. build up the narrow line of coral barely flush with the level of the sea. The western slope is much more gentle, and here the reef consists of a number of half -made narrow islands. These are mere strips of sand formed by the breaking-up of the exposed masses of coral, which are gradually cemented together by the accumulation of the loose material held in suspension by the water. Here, in the shallower parts, grow huge masses of Astrsea, of Gorgoniae, of Meeandrina, which now and then rise to the surface. Along the Cuban coast the dredge brought up immense numbers of siliceous sponges, a species of Favosites, which we are tantali singly told is perhaps the most interesting coral ever dredged. We presume it was found living, and we all know that this genus was founded by Lamarck for some fossil corals, only found in the very oldest strata (Silurian and Devonian), a young Holopus in excellent condition (probably the fourth or fifth speci- men ever found). The dredge worked well to a depth of upwards of 2,000 fathoms. One haul in 860 fathoms brought up an unusually large number of two and one valved mollusca, including many of exquisite beauty. Some most gorgeously coloured Crustacea were brought up from a depth of 1,920 fathoms, and what are We to say to an isopod allied to Aega, and upwards of eleven inches in length and three in width ? Amongst the strange fish, we read of one like a huge tadpole with a gigantic round cartilaginous head, and without eyes ; of another with a drawn-out flat head, very little eyes, but possessed of gigantic filaments, as long as the whole body, and extendmg from the tips of the pectoral and lower caudal fins. Some of the Holothurians were striped with bands of a deep crimson colour. Certainly the wonders of the deep-sea are not yet exhausted, and though the treasures found by our own Challenger expedition were great, it could reap the produce of but a very narrow belt out of the gieat expanse of the ocean world. A steel wire rope was used by Capt. Sigsbee. The time required to reel in was always below one minute per 100 fathoms, sometimes not more than twenty seconds, while the time required to strike bottom averaged thirty-five to. forty-five seconds per 100 fathoms in the deepest sound- ings of 2,000 fathoms. The wire rope was of galvanised steel with a hemp coil ; it measured i| inch in circum- ference, and weighed i lb. to the fathom, and had a break- ing strain of over 8,600 lbs., and its own weight made the use of heavy weights to sink it unnecessary. The Blake is now on a cruise to explore the inner por- tions of the Gulf of Mexico, commencing with a run from the Tortugas to the mouth of the Mississippi River, irk which we wish her crew of all ranks every success. E. Perceval Wright METEOROLOGICAL NOTES Mr. Ellis has made a valuable contribution to the diurnal variation of the barometer in a paper published in they^«r«rt/of the Meteorological Society of London, which gives the hourly variations from the means of each month as deduced from a discussion of the photographic records taken at the Royal Observatory during the twenty years ending 1873. The forenoon maximum occurs from May to July about 9 AM., being fully an hour later than at Kew. The morning minimum at the same season becomes less marked than at other times of the year, as happens irk situations more or less continental in middle and higher latitudes ; and this feature of the diurnal variation is, it may be remarked, decidedly better marked at Kew than at Greenwich. Mr. Ellis gives, for comparison with Green- wich, the curves for Oxford, Washington, Cape of Good Hope, and Ascension, from which he draws the broad con- clusion that in high latitudes the forenoon maximum occurs earlier when the sun rises early, it being however omitted to be pointed out that this holds good only in situations more or less continental or removed from the more imme- diate influence of the sea. Thus the forenoon maxi- mum which occurs at Greenwich at 9 a.m. and at Kew at 8 A.M,, is delayed at Falmouth and Valentia to about 1 1 A.M. or noon ; whilst at Helder the time of its occur- rence in June is about 2 P.M. The hourly barometric values for the twenty years were arranged with reference to the time of the moon's meridian passage with the result that no certain indication of lunar variation was apparent. We hope that by-and-by the main details of this elaborate discussion will be printed ; such details as will embrace, at least, the hourly values of each day and month of the twenty years for the examination of many inquiries re- ferring to both civil and lunar days, which are now rising into questions of the highest importance. Prof. Loomis has recently examined all the cases of violent winds of the United States which have been recorded as having occurred from September, 1872, to May, 1874, the number of cases on which the wind rose to or exceeded forty miles an hour being 250. During the six months from November to April,, violent winds were more than five times as frequent as during the other six months of the year. The great preponderance of violent winds are from the north ; thus from north-east, north, and north-west, the number were 143, whereas from south-east, south, and south-west, there were only 58. Generally speaking, violent winds increase in frequency and intensity over North America with lati- tude. Local conditions exercise a considerable influence on the force of the wind. Thus violent winds are of most frequent occurrence near the Gulf of St. Lawrence and the Great Lakes, particularly Lakes Michigan and Erie. June 20, 1878] NATURE 199 High winds are also frequent along the dry prairie region bordering on the Rocky Mountains. An interesting table is gfiven, showing the relation between the wind's velocity and the barometric gradients, which may be accepted as rough approximations, but the stations in the United States and in Canada from which the isobaric lines have been drawn, are by far too wide apart from each other to supply the data required in dealing with this important phase of weather. Under the heading of a " Brief Sketch of the Meteo- rology of the Bombay Presidency in 1876," Mr. Fred. Chambers introduces some original suggestions re- garding the Indian drought of that year. His method of examination proceeds on the supposition that the droughts of India may be connected with the vary- ing states of the sun's surface as regards tempera- ture, and in the light of the consequences which result from this supposition the observations made in the presidency, from Kurrachee, in the north, to Belgaum in the south, are discussed from which it is shown that the abnormal barometric movements of 1876 were mainly variations in the intensity of the usual seasonal move- ments; and that, as regards the rainfalf, among the causes which produced the drought in 1876, were those very causes which in ordinary years produce a less average rainfall in the eastern than in the western districts of the Presidency. The general conclusion which is drawn, explicitly for the guidance of further inquiry, is that the same principles which explain the usual alternation of the seasons, also explain in a great measure the varying rainfalls of different years. This mode of discussion deserves to be widely adopted in dealing with secular variations in meteorological phenomena, particularly in view of the large scientific issues involved in the relations between the solar and terrestrial atmospheres. Prof. Mohn publishes a brief account of the fall of the volcanic ash which was shot up into the air during the eruption in Iceland on March 29, 1875 (Nature, vol. xi. p. 514), and thence carried eastward by the strong westerly winds which then prevailed ; and a map is given showing by curved lines the hours at which the ash began to fall along the extensive track stretching 980 miles from Iceland to Stockholm. The most interesting point in the inquiry is the manner in which the lofty mountain range of Scandinavia appears to have influenced the hour of the fall of the ash. Since the time between the ash leaving Ice- iand and falling on the coast to the east of Stockholm was twenty-seven hours, the mean rate at which it was borne onward was thirty-six miles per hour. During the first twelve hours of its course it drifted eastwards at a uniform rate of fifty miles an hour. It had then approached to from sixty to eighty miles of the mountains of Norway, but thereafter its speed suddenly fell from fifty to twenty- seven miles an hour. The interesting point is that a mountain system such as that of Norway, lying across the wind's path, would appear to exercise a decided influence in reducing the velocity of the aerial current under its level to the extent of nearly one-half, at a distance of sixty to eighty miles to windward. OUR ASTRONOMICAL COLUMN The Total Solar Eclipses of May 16, 1882, and August 18, 1887.— There will be two total eclipses of the sun within the next ten years, which may be observed without entailing a long sea-voyage from this country. The first will take place on May 16 (or May 17, civil reckoning), 1882. In this eclipse the central line com- mences in long. 3° 11' W., lat. 10° 40' N. ; totality will occur with the sun on the meridian in 63° 44' E. and 38° 35' N., and at sunset in 138^ 51' E. and 25° 25' N. The duration of total eclipse on this occasion is compara- tively short. Probably if observers proceed from England to the central line, they would station themselves in Upper Egypt, not far from one ."of the points whence the late transit of Venus was successfully observed. In 32° E. and 2(P 44' N. close to this line, totahty commences at 2oh. 32m. 45s, and continues im. los. At a point upon the same, not far from Sherm, at the extremity of the peninsula of Sinai, on the Gulf of Akaba, in 34° 28' E., and 28° 2' N., the duration of totality is im. 17s. The eclipse will be total at Teheran for im. 4s. with the sun at an altitude of 67°, commencing May 16, at 22h. 36m. los. local mean time; the central line passes about fifteen miles south of this place. A total eclipse may also be witnessed, though for a few seconds only, near Shanghai. The second of the eclipses to whiph reference has been made is the one long mentioned in our popular treatises as the next eclipse that will be total in England, but the central line commences in Germany. The following are the elements — 1, August 18, at S. G.M.T. of conjunction in R.A., \i I7h. 14m. 33s. R.A. ... Moon's hourly motion in R.A Sun's „ ,, Moon's declination ... Sun's ,, ... Moon's hourly motion in declination Sun's „ „ Moon's horizontal parallax " «..* ~. .." Sun's ,, ,, r i..H for central eclipse. ( - [1 76137] ) for S. limit. In these formulEe, as has been previously explained when presenting similar ones, all quantities within square brackets are logarithms ; / is the geocenti'ic latitude, or the geographical latitude diminished by the angle of the vertical; L the longitude from Greenwich, counted positive towards the east ; and / results in mean time at Greenwich. First, let it be required to find the latitude of the central line and the north and south limits in the longi- tude of the Observatory at Moscow, 2h. 30m. 17s., or 37° 34''3 east of Greenwich. For North Limit. Constant -i 7761 6 n ... + 1 '94089 Longitude Constant ... +37 34-3 -. -75 51-8 A ... -38 17-5 n. sin. N ... +1-92757 Constant Cos. A .. + 1 '43336 ... +9-89480 n. cos. N ... +1-32816 Tan. N ... +0-59941 N ... ... 75 52-9 Sin. N ... +9-98668 n ... +1-94089 For Central Line. Constant ... -1-76883 Cos. (N + /) N + / .. N Angle of vert. 9-83527 Constant i '87565 Sin. w... 9 '5 1 962 133 ii-o 75 52-9 57 18-1 io'5 Cos. (N + /). N + / N ... + I -94089 -9 '82794 132 17-4 75 52-9 56 24-5 10-6 Lat. of N. limit ... 57 28 '6 For South Limit. 56I35-I Constant « Cos. (N + /) N + / N ... Angle of vert. Lat of S. limit -1-76137 + 1 -94089 -9-82048 131 245 75 52-9 55 31-6 IO-8 55 424 Add angle of vert... Lat. of central line. In this manner by assuming other longitudes near that of Moscow we trace out the belt of totality. Next, to find the times of beginning and ending of the total phase at any point in the vicinity. Calculating for the observatory of Moscow, the geographical latitude of which is + 55° 45'-3, we proceed thus : — Geographical latitude... +55 45-3 Constant... -23 34-5 Angle of the vertical ... 10-7 L +37 34-3 Geocentric latitude (/).. +55 34'6 B ... ... +13 598 Constant ... -1-92757 Constant . - +1-43336 Sin./ ... +9-91639 Cos. / . ... +9*75228 Cos. A ... . . ... +9-89480 -1-84396 + I '08044 No ... -69-8167 + 70-7604 No . ... +12-0347 Constant ■ ... +58-7257 Nat. cos. 10 ... ..."+ 0-9437 + 70-7604 Log. cos. w ... ... +9-97483 I -39527 Constant -3-11123 Constant -3-81636 Sin./... +9-91639 Cos./... +9-75228 Cos. B... +9-98691 No. 24^-8 No. - 3-02762 - 1065S-6 - 3593"8 No. -3-55555 - 3593^-& ~ 4659^-4 h. m. s. - I 17 39-4 Constant 17 32 29 6 16 14 50-2 Long. E. 2 30 17-0 Middle.. 1845 7-2 Moscow M.T. T24'8 ^hs 44 42-4 '''S \ 'S 45 32-0 GEOGRAPHICAL NOTES The Japan Gazette publishes an account of a vis't recently paid by a Japanese steamer to the Bonin Islands, about which but little is known. Some eighteen months ago the Japanese took possession of the islands (which are in N. laL 27°, about 520 miles from Yoko- hama), and established their head-quarters at Port Lloyd, Peel Island, which is the only harbour in the Bonins. The islands are described as high, rocky, and even mountainous; and the shores are, for the most part, precipitous, and lined with coral reefs. The vegetation is chiefly tropical, palms of various kinds being abundant. Wild goats and pigs abound on all the islands, and deer on one of them. Lemons, sweet potatoes, bananas, Indian corn, &c., thrive there ; but the attempt to intro- duce cocoa-nut trees has not yet proved successful. On the return voyage the steamer visited the outlying Japanese island of Hachijo, which has an area of forty miles, and is said to contain 10,000 inhabitants. It is mountainous, and its sides to a great extent precipitous. At the northern end of the island there is a volcanic peak, rising to a height of 2,800 feet above the sea. The roads on the island are mere narrow and stony paths, and the people are poor. Three-fifths of the population are said to be women. Almost every available spot on the hill-sides in Hachijo is terraced and cultivated, but suffi- cient rice cannot be grown, so that sweet potatoes form one of the principal articles of food. At the meeting of the subscribers to the African Explo- ration Fund held the other day, a resolution was passed to adopt the route recommended by the Committee, from Dar-es-Salaam, towards the northern end of Lake Nyassa, and thence, if possible, to the south end of Lake Tanganyika. The return journey might be made as far as possible along the valley of Lufigi. As we have already intimated, Mr. Keith Johnston, with whom will be asso- ciated another European, will lead the expedition, which will probably leave England in October next. The distribution of prizes of the Geographical Society of Paris, which had been postponed owing to the forth- coming exhibition, will take place at the Sorbonne on the 27th inst. Mr. Stanley, it is understood, will be present to- receive the gold medal awarded him. The National Geographical Congress v/ill take place in the beginning of September in the hotel built by the Paris Geographical Society, and which will be inaugurated on this occasion. It is said on good authority that the presidency of that Congress Avill be given to M. de Lesseps. Jtme 20, 1878] NATURE 201 THE GREAT FROZEN SEA 1 MANY readers, we believe, will prefer this brief brightly written narrative of the last English Arctic Expedition to the two weighty volumes of Sir George Nares's, recently noticed in these pages. Capt. Markham is an enthusiastic Arctic explorer, and as these volumes testify, is well fitted by his personal qualities, his expe- rience, and accomplishments, to take a leading part in work of this kind. He has evidently a thorough know- ledge of Arctic work and a full appreciation of the kind of observations which ought to be attended to in an Arctic expedition. His interesting volume affords a very satisfactory idea of the incidents of the expedition and of the nature and amount of work done. Capt. Markham' s name must be known to all as the leader of the sledge party that attained the highest northern latitude, and as might be expected, his pages contain an impressive narrative of the adventures of the party. As one reads the story of this heroic attempt to reach the pole he is not merely surprised that the party turned when they did, but that they did not resign the attempt at the end of the first week, for it must then have become evident that the goal was unattainable by that route at that season with the means at command. Had the men not been made of splendid stuff, physically and morally, they could not possibly have endured the terrible hardships described by Capt. Markham. Cer- tainly Sir George Nares did not exaggerate when, in addressing his men before leaving England, he told them " that if they could imagine the hardest work that they had ever been called upon to perform in their lives inten- sified to the utmost degree, it would only be as child's play in comparison with the work they would have to perform in sledging." Capt. Markham seems to think that work by the \ Highest northern camp, 33* 20' 26" N. lat Smith Sound route is practically complete; and he leaves one with the impression that it would be useless to attempt to reach the pole by that route. Assuming that the attainment of the pole is in itself a worthy object for an expedition, we are inclined to think that the conclu- sion as to its unattainability has been too hastily drawn from the experience of one expedition. At the same time we quite agree with Capt. Markham that there are other routes which, while they hold out some hope of a successful passage to the pole, would also afford oppor- tunities of obtaining valuable scientific observations. Capt. Markham rightly says that Behring Strait is a portal leading to a vast region, the history of which has hitherto been as a sealed book. This, it is stated, is the ' The Great Frozen Sea. A Personal Narrative of the Voyage of] the Alert during the Arctic Expedition of 1875-76. By Capt. A. H. Markham, R.N. (late Commander of H. M.S. Alert). (London; Daldy, Isbister, and Co. 1878.) route to be followed next year by the expedition to be sent out by Mr. Gordon Bennett. Mr. Bennett is having a map of the polar regions constructed for the purpose of showing the effect of the various currents towards and from the polar area, and, if one may judge from this, there is much to say in favour of the Behring Strait route ; but all such polar-current charts must be re- garded with grave suspicion, as being founded so largely on conjecture. We quite coincide with Capt. Markham' s strong advocacy of the route by Franz Josef Land. So far as known at present, that, we think, is the best basis of operations for further work towards the north. Per- haps we may hear of something important being done in this direction by the Dutch Expedition which recently went out in the Willem Barentz. Capt. Markham gives a fair idea of the kind of scien- tific work carried on by the expedition, and we hope that the many magnetical, hydrographical, meteorological, 202 NATURE \yune 20, 1878 and other physicai observations which were made will be published in well-arranged form. At the furthest point reached, a bread bag filled with the scrapings of the pannikins and a little pemmican was lowered to the bwittom of the sea, and, having been kept there for some hours, was hauled up, and was found to be almost alive jjwith numerous small crustaceans and foraminifera. With b/the thermometer a series of temperatures was taken 'at * every ten fathoms, while the specific gravity of the sur- face-water was also obtained. Tidal action was apparent, though it was impossible to collect any exact data. Capt. Markham, like his relative, Mr. C. R. Markham, is evidently of opinion that the Eskimo entered America from Asia, spreading eastward, and finding their way to Greenland by crossing at almost 8i° 54'. This is, we confess, the theory which most readily presents itself, but those who have studied the subject most deeply, and in all its aspects, have come to the conclusion that the Eskimo are virtually indigenous, and came northwards from the American continent itself, the migration being from America to Asia, and not the other way. Indeed, some ethnologists go so far as to maintain the essential unity of origin of all the American families, and that all the differences in physique, language, &c., may be ex- plained by differences of environment. In the case of America, probably, more than anywhere else, language is a really important factor in the ethnological problem. (See Prof. Sayce' s article last week on " The Ethnology of North-West America.") Capt. Markham gives an extremely pleasant account of the winter amusements on board the Alert — the Royal Arctic Theatre, the Thursday Pops., the school for the men, &c. The last-mentioned institution appears to have been a great success^ and we are sure the men will feel the benefit of it all their lives. One feature of the Thurs- day Pops, we must mention with special approval ; except on the evenings exclusively devoted to the legitimate drama, these entertainments were always preceded by a lecture delivered by one of the officers on some interesting and at the same time instructive subject, adapted to the knowledge and intelligence of the audience. In this way thirteen lectures were given altogether, and with the exception of one on a historical subject by Mr. White and one on Sledging Experiments by Capt, Nares, they were all on scientific subjects. Capt. Nares began the series by a lecture on Astronomy, which was followed by lectures by the other officers on Magnetism, Geology, Meteorology, Steam, Mock Moons under the Microscope, Light, Astro- nomy again, Food in the Arctic Regions, Arctic Plants, Hydrostatics. Indeed it is difficult to conceive that more could have been done to enable the expedition to pass as cheerful a winter as possible under the circumstances. Altogether Capt. Markham' s work is a thoroughly interesting and instructive narrative of a memorable ex- pedition. The numerous illustrations and the maps add considerably to its value. ON THE STRUCTURE AND DEVELOPMENT OF THE SNAKE IN my paper on the skull of this type (see abstract Proc. Roy Soc, January 10, 1878, pp. 13-16) I spoke of the snake as "lying at the very base of the gill-less \txt&- brata, and possessing a skull at once the simplest and yet the most curiously specialised," of any of the many kinds I have worked out. As far as existing forms of reptiles are concerned, the snake does lie at the very base, yet, on the whole, I am inclined to add it to the other limbless lizards, such as the blind-worm and the amphisbasna, and to consider it, therefore, as a lizard which has had its limbs starved out for special purposes. Much of the cranio-facial axis of the snake remains in a very primordial condition, but the outworks of the skull are modified to such a degree that " the power of nature could no further go." I have not yet worked out the skull in the amphis- baenidas, but I expect to find it to have many things in common with that of the serpentiform amphibia, the " CcEcilians." But the "Anguidae," taking the common blind- worm {Annuls fragilts) as an example, are merely "Scin- coids" that have dropped their limbs but retained their limb-girdles : they are lizards to all intents and pur- poses, and the native kind only differs from its quadru- pedal relatives, in possessing an additional segment ("mesopterygoid'') in the " pterygo-palatine " arcade, a segment common in osseous fishes and birds, but sup- pressed, as a rule, in the scaly reptiles. As to that which is archaic, the chameleons so com- mon in Africa, and the unique New Zealand Hatteria {Sphefwdofi), these outliers of the lizard tribe are evidently more generalised than the serpents. But all these forms — snake, tropical lizard, legless lizard, and old aberrant lizards — all these come as close to the bird as the ptipa of a dragon-fly does to the imago of the same insect. With regard to the earlier stages and to the mode of development of the embryo, generally, I have stated in my paper (pp. 9 and 10), that " As to the general embryo- logical study of the snake's embryo, it may be remarked that it is almost exactly that of the birds. Comparing my own observations on this low type with the results given in the study of the chick in Foster and Balfour's excellent work, I find that few paragraphs in it would need any material alteration, and that the figures would mostly serve very accurately if in that work the word chick- were to be exchanged for that of snake-e.Tc^x^'o. The development of the vesicles of the brain, the organs of special sense, the rudiments of the cranium and face^ — those things that come across my path, to say nothing of the rest of the growing germ, all are developed similarly in the snake, below, and in the bird, above." If this be so, the modifications undergone afterwards, in the specialisation of the skull and skeleton generally, and in the appearing and packing of the enclothing muscular masses, those " cunning machines " that do the gymnastics of the body — the development and endless modifications of these parts must be of the greatest interest. I must refer to Professor Huxley's paper "On the Classification of Birds" iJLooi. Proc, 1867, pp. 415-418) for a comparison of the bird with the reptile, and for the reasons existing that have led modern anatomical zoolo- gists to put the reptiles and birds into one group, viz., the " Sauropsida." ^ With regard to the loss of limbs it is not a httle re- markable that, on the theory of the "Ratitse" being parental to the " Carinatae," in the bird class, that pair of limbs which was to be most metamorphosed was not quickened into new life until it had died. Morphogically, the wingless Dinornis stands directly beneath the whole of the "winged fowl" known to us, and the steps and stages from that monster up to the sun-bird and the hum- ming-bird are very gentle and gradual. But there were reptiles in the olden times " that spread their limber fans for wings," and there were true birds also which had evidently only just escaped from the rep- tilian territory, as the Archaopteryx, for instance, and these are seen to be actually modifying the paw into a wing. Perchance the birds grew out from many a kind of old generalised reptile ; yet, be this as it may, the eagle him- self is not a more powerful or beautiful creature than a python or a boa, nor is there much more to wonder at in ' That account of: the "Sauropsida" needs a little modification in the light of newer discoveries. I have given such an improved account in my article on the Anatomy of Birds in the ninth edition of the "Encyclo- paedia Britannioa," vol. iii., p. 278. yune 20, 1878] NATURE 203 the manner in which the morphological force has en- clothed a vertebrated animal in the case of the bird than in that of the huge "creeping thing." Certainly the skull is in some respects much more simple in the serpent th^n in the bird, for the bird having built up its skull with all the old reptilian architectural elements, afterwards blots out their distinctness for the most part, and only leaves marks here and there of the early subdivision of the parts. But this is due to *' the hot condition of their blood " and, especially in the higher kinds, the "altrices," the life-vessel of a bird almost literally boils over ; in a few short weeks the shapeless embryo of a swallow or a swift is able to join the " airy caravan " of its migrating parenti Head of Embryo Snake, i inch long, magnified 8 diameters.. and relations "high over seas," and in far distant countries seek for perpetual summer. The great serpent, I ween, took a century or two to finish in its fulness his huge bulk ; time, so important to the "turtle, and the crane, and the swallow," could be of no importance whatever to pre-Adamite boa-constrictors and pythons. Was not the whole jungle theirs, and theirs also every kid and fawn, to say nothing of the luckless imwary bird 1 That the spinal column is as complete and beautiful a piece of machinery in a boa-ronstrictor or ordinary snake as in the bird there can be no doubt. Talk of specialisation ! Why, Prof. Owen's terms for the parts and processes of a snake's vertebra would take Embrj'O of Snake, J inch, magnified 8 diameters. up half a column in a scientific glossary. I will g-ive a few of his terms; — "Neural-spine," " neurapophysis," " post-zygaphophysis," " prae-zygapophysis," "zygo- sphene," "zygantrum," " procoelous," articular cup of "centrum," posterior ball for next cup of "centrum," "neural canal," oval articular head for ribs on each " diapophysis," and oval concavity on head of rib. Four hundred vertebrae, most of which have all these parts ! Surely this creature was made by Nature herself, and by no "'prentice hand." The sinuous cylindroidal facets, fore and aft, on the bird's centrum are not a whit more perfect than the cup-and-ball of the snake's vertebra; and in all respects the articulation of the serpent's spine is so exquisitely perfect as to beggar all human inventions of joints and hinges. Only just a little motion of joint on joint is allowed, each joint set into the other, so that nothing can part them without crushing them entirely; and yet a *Kost perfect and delicate motion of cup in ball, wedge tin 'cavity, and of the oblique overlapping facet on the oblique facet beneath it — all these ar€ harmonised together, and just allow a gentle bend of bone on bone, and a gentle rolling of vertebra on vertebra. Multiply by 400 this limited motion, this arrested curve, and you get a motion such as would, if likely to be applied to you, personally, make "all your safety to lie in remotion, and your best defence absence." The curve, so small as made by one joint bending on another, would, in its sum total, be sufficient to engirdle a luckless anatomist several times over. In the bird's head nearly all the fair details of its early architecture are plastered over by periosteal bone, by the ruthless processes of a steady ankylosis that removes landmark after landmark. Not so in the serpent, although, with a wise prevision (enough to satisfy the most craving teleologist, who, wondering, asks you if you see no design in Nature), ankylosis comes in to perfect the " strong box" in which this wise [cunning] creature keeps its limited brain. ^ The organ of its mind is thus safely lodged so that no foot may crush or wild beast break its casket ; thus with its "cruel venom" the adder "bites the horse heels so that the rider falls backwards," and is in no fear of that heaviest of all feet, the foot of the soUped. The (relatively) deaf adder has its ear-organs encased in adamant ; they with the cranial bones are " shut up together as with a close seal. One is so near to another that no air can come between them. They are joined one to another ; they stick together that they cannot be sundered." So much for the cranium proper ; but how about \\ve^face? The/ace is a loose framework of bones tied together into one piece of work by an infinite amount of "yellow elastic tissue," and the opening of the capacious "maw" is surrounded and defended by bars of ivory-like bone, many of which are beset with retral teeth pointed like needles and sharp as lancets. Your serpent, with all his wisdom, does not "mouth" his words ; he only hisses ; but he mouths his prey as no other creature does; and the "shirt of Nessus" was not a more dreadful robe to wear than the distensible body of a python, inclosing, ingulphing, suffocating, and digesting its limp and helpless prey. With regard to the relation of the snakes to the existing lizards, it is a remarkable fact that, whilst they have no tympanic cavity, in which character they agree with Sphenodon and the chamaeleons, yet a small cochlea buds out from the vestibule, and there is to it a " fenestra rotunda." The chamaeleon is void of this structure, and thus in that respect is as low as a frog. The lower jaw and its pier (quadrate) was altogether directed forwards in the early embryo of the snake ; afterwards the pier and the free mandible are articulated at a very acute angle, the squamosal touches the temporal regions by its apex, and to its base the long rib-like quadrate is articulated. The quadrate thus is made to pass over the "columella auris,".which also is directed backwards ; on that rod there was a small " stylo-hyal " ; the quadrate picks up this use- less remnant, and glues it, by partial ankylosis, to its inner face. Thus the counterpart of the human "styloid process" is ankylosed to the bone that answers to the head of the "malleus." W. K. Parker ' I am frequently a?ked whether I believe in design, and am always at a loss how to answer the question, it seems to be to me so perfectly gratuitous. If the questioner would but give me time, I would promise to write him a bock upon the fitnesses to be seen in lifrog at even in a Jlea that should be as large as a family Bible. 204 NATURE \yu7ie 20, 1878 A FOSSIL SPARROW-LIKE BIRD WE recently referred to a new genus and species of Passerine bird, described by Mr. J. A. Allen from a specimen found preserved in the insect-bearing shales of Florissant, Colorado. We give an illustration of these re- mains, which consist of the greater part of a skeleton, embracing all of the bones of the anterior and posterior extremities (excepting the femora). Unfortunately, the bill and the anterior portion of the head are wanting,but the Fig. outlines of the remainder of the head and of the neck are distinctly traceable. The bones are all in situ, and indicate beyond question a high ornithic type, probably referable to the Oscine division of the Passeres. The specimen bears also remarkably distinct impressions of the wings and tail, indicating not only the general form of these parts, but even the shafts and barbs of the feathers. In size and in general proportions the present species differs little from the Scarlet Tanager {Pyranga rubra) or the Cedar-bird (/iw/^/zi- cedrorum). The bones of the wings, as well as the wings themselves, indicate a similar alar development, but the tarsi and feet are rather smaller and weaker ; and hence in this point the agree- ment is better with the short-legged Pewees (genus Contopus). These features indicate arboreal habits and well-developed powers of flight. The absence of the bill renders it impossible to assign the species to any par- ticular family, but the fossil on the whole gives the im- pression of Fringilline affinities. It is called PalcBOspiza bella. Its wings are rather long and pointed; the tail is (apparently i) about two- thirds the length of the wing, rounded or graduated, the outer feathers (as preserved) being much shorter than the inner. The feet and toes it will be seen are strictly those of a perching bird, and the proportionate length of the bones of the fore and hind limbs is the same as in ordinary arboreal Passeres, especially as represented by the TanagridcB. The most remarkable feature of the specimen is the definiteness of the feather impressions. Both the shafts and the barbs are shown with great distinctness in the rectrices, and the tips of the primaries of one wing are also sharply defined, overlying the edge of the partly- expanded tail. The tip of the opposite wing can also be seen beneath the tail. The feet are so beautifully pre- served that even the claws are perfectly distinct (Fig. i). ' The character of the tail must be given with reservation, since it is not quite certain that the whole of the tail, or that the exact form of the termmal portion, is shown, especially as the preserved impression is some- what unsymmetrical. Another very imperfect specimen from the same locality, and probably representing the same species, consists of the tip of the tail and about the apical third of a half- FlG. 2. expanded wirtg (Fig. 2). In this example the tail is also pointed and graduated. The larger specimen, that first described, is divided into June 20, 1 8 78 J NATURE 205 an upper and a lower half, the greater part, however, ad- hering to the lower slab. The bones adhere about equally to the two faces. The drawing is made from the lower slab, with some of the details filled in from the upper one. The feather impressions are about equally distinct on both, and where in either case the bones are absent exact moulds of them remain, so that the structure can be seen and measurements taken almost equally well from either slab. The species here described is of special interest as being the first fossil Passerine bird discovered in North America, although birds of this group have been known for many years from the tertiary deposits of Europe. The author is indebted for the opportunity of describ- ing these interesting specimens to Mr. S. H. Scudder, who obtained them during his last season's (1877) ex- plorations of the Florissant insect-beds. The specimens are now the property of the Boston Society of Natural History. NOTES A TELEGRAM from Sydney, dated June 17, announces the death of the Rev. W. B. Clarke, the eminent Australian geologist. Mr. Clarke was a Fellow of the Royal Society. At Gotha a monument erected in memory of the well-known naturaUst, Prof. Johann Friedrich Blumenbach, who died at Gottingen, in 1840, was unveiled on May 19. It consists of a gigantic block of stone bearing a portrait of Blumenbach and an inscription, and was executed after the design of the eminent architect, Herr Eelbo. The next session of the French Association for the Advancement of Science will be held at Paris from August 22 to 29. The presidents of sections have been appointed by the general committee. Among them we find the names of MM. Cornu, Quatrefages, Bertillon, Maunoir, Wurtz, Herve-Mangon, Baron Thcnard. It is stated that for the first time each of these presidents will deliver an introduc- tory address on the work of his section, after the example of the British Association. Two Japanese astronomers Janagi and Issono, are busily engaged in studying the equipment of our European observa- tories, and the best methods of conducting observations. At present they are visiting the Seeberger observatory at Gotha. After an extensive summer tour they intend to spend the autumn in Berlin, a city for which Japanese students in various branches of science seem to have a peculiar liking. The scientific demonstrations, which we announced as being organised in connection with the I'aris Exhibition, were com- menced on June 17 by the Anthropological Commission. Scien. tific explanations will be given four times a week, from ten o'clock by three professors of the Anthropological School of Paris : Monday and Thursday on Prehistoric Anthropology by M. de Mortillet ; Tuesday, on Demography, by Dr. Bertillon ; and Friday, by Dr. Topinard, on General Anthropology. The General Association for Lectures and Promenades has been authorised by the Minister of Public Works to complete its organisation, and its programme will be published soon. No fee is taken beside the charge of the usual admittance ticket, 10 deniers, collected at the gates of the Exhibition. The Committee of the Meteorological Congress, which will take place in Paris at the end of August, under the presidency of M. Herve-Mangon, have issued their programme of questions. The first of the International Congresses arranged for by'the French Government has taken place at the Trocadero. The So- ciete des Agriculteurs de France took the initiative under the pre- sidency of the Marquis de Dampierre, the Prince of Wales and Lord Lyons being present. But the attendance was very limited, not more than five or six hundred persons being present in a room fitted to accommodate many thousands. The number of delegates of French and foreign agricultural associations was. 112, a large proportion belonging to English societies. The General Secretary delivered an elaborate address in which he reviewed the condition of agriculture in the world generally and principally in England, which may be considered as the home of modern scientific 'agriculture. The ordinary meetings of the Congress take place in the Pavilion de Flore, Tuileries, and the concluding sitting-will .be held in the large hall at the Trocadero. The same organisation has been adopted for all the congresses belonging to the Exhibition. The/ournal Officiel has published their dates and details of organisation. The Paris Prefect of Police has granted the authorisation fo» the creation of a club of students (Cercle des Ecoles). This institution is organised by a committee of bond fide students and professors of -the several Government schools and universities, among them being MM. Littre, Herve-Mangon, Acarias, Wurtz, Robin, Paul Bert, &c., &c. The Minister of Public Instruction has sent his approbation. Social, political, aad religious discussions will be strictly forbidden in the institution. It is the first time, at least daring the present century, that such an authorisation has been given in Paris. We learn, with pleasure, that at a meeting held at Barrow- in-Furness, on June 3, the Committee of the Naturalists' Field Club belonging to that town- determined to organise a scheme for sending representatives (artisans, if possible) to the Paris Exhibition, with the view of collecting information in con- nection with the various branches of science which are there practically illustrated, one of the conditions being that the result of the observations should be imparted to the club in the form of lectures during the ensuing winter. Promises of substantial support have been received from several of the leading men in the district, and the scheme is expected to be shortly in workii^ order. We have often had occasion to refer to the progress of science in New Zealand. Our contemporary. The Colonies and India, has, in a recent number, an article on education in New Zealand, from which we gather the follow ing facts : — It seems that upwards of 600,000 acres of land is now set apart to provide funds for these educational establishments. Our contemporary may well ask, "Compared with this, what are the endowments made in this or in any other country in the Old World ? What may not be hoped from such a commencement, and from a people possessed of such foresight and liberality?" There, is a university established with a Royal Charter whose degrees are recognised as equal to those of the English univer- sities. As yet it is only in its infancy. Having no examiners of its own it has still to conduct the examinations for degrees, through means of the professional staff of the colleges which are affiliated to it. The Canterbury College is thus united to it, where the coiurse i eludes classics, mathematics, modern languages, history, English literature, natural philosophy, political economy, and jurisprudence. This college has received as an endowment 350,000 acres of land, judiciously selected in various districts, and producing a rental of several thousands per annum. In the course of years this will no doubt prove to be of enormous value. "It is open to purchase, at any time, at the rate of 2/. an acre ; 700,000/. is therefore the maximum at which this endowment can arrive. In addition to this there is also a landed endowment for educational purposes, including not only the elementary schools but those of technical science, for classics and superior education, a museum and library, a college of agriculture, and a normal school for the instruction of teachers, a most useful idea." BeJdes these there is the 206 NA TURE \yune 20, 1878 Canterbury mu cum and public library, and various siuilar institutions in the country towns. Lectures are given in the museum ; and it is hoped that in cour. e of time the library will become as large, or at least as useful, as those of Mel- bourne and Boston. Twenty scholarships of 40/. a year, tenable for two years for students of schooh, colleges, or under private tuition, have already been founded by the Board of Education, and it is intended to increase the number. At Dunedin, the capital of Otago, which is chiefly a Scotch settlement, the same eagerness for education prevails. There is a univen;ity and a school of art, a boys' and girls' high school, and district grammar schools ; besides which there are athenscums and public libraries in nearly all the country villages. "Here, as at Canterbury, large landed endowments have been made for the above-named objects. Two hundred thousand acres have been settled upon the university. The buildings have already cost 30,000/. ; they are handsome and well-situated. As yet the number of students does not exceed eighty, to instruct whom there are five professors in addition to one of moral and mental philosophy, endowed with 600/. a year by the synod of Otago. A valuable library is attached, which it is intended shall be utilised as a free public library. Although this has been styled a university, it can only be looked upon as a college affiliated to the Univer.-ity of New Zealand. A Royal Charter has been refused to it, and its degrees are not recog- nised. Nearly one thousand of the elder pupils at the other schools receive, at the school of art, instruction in freehand drawing, painting from copies, from nature, and from the human figure, 'de igning, practical geometry, perspective, mechanical and architectural drawing. In the provinces of Wellington, Nelson, and Auckland there are collegiate bodies affiliated to the University of New Zealand, and there are also provisions for eleaientary instruction. The general dissemina- tion and desire for knowledge, it is said, is "laying a s\u"e foundation of a people able to conduct their own affiiirs, and giving promise of a bright future in w^hat has well been termed the Great Britain of the south." We understand that Mr. Thomas Denman, Lecturer on Physiology at the Birkbeck Institution and Physical Science Lecturer at the Working Men's College, has co npiled a Glossary of Biological, Anatomical, and Physiological Terms, which will shortly be published in a small crown 8vo volume by Messrs. Griffith and Farran. The Chinese coast was visited by a terrific cyclone on April 12. It appeared to take its origin about fifty miles from Macao, and moved directly northwards, devastating eveiything within a path of about 700 feet in width. The European settlement on the Island of Schameen was reduced to a ruin, and the havoc created by the storm in Canton and the neighbourhood is beyond calculation. The loss of life is estimated at 6,ox) to 8,oco. An eye-witness states, in a letter to a Vienna journal, that the cyclone was immediately preceded by a hail-storm, the tempera- ture being at 80° F. Mr. Talfourd Ely, the Secretary of University College, London, asks us to state, to prevent misunderstanding, that the admission of women to classes in that College does not apply to the Faculty of Medicine, but only to tae Faculties of Arts and Law, and of Science. During the past year the Austrian Educational Department has maintained a party of geologists in Northern Greece for the purpose of preparing a reliable geological chart of this part of the kingdom, a district which, until within late years, has been almost entirely closed to scientific examination. A portion of the results have been submitted to the Vienna Academy recently in the form'of a paper on the "Geological Structure of Attica, Boeotia, Locris, and Parnassus," accompanied by a number of barometric measurements of the heights of Greek mountains. In 1866 the Swiss government took active measures to pre- serve the namerous erratic boulders scattered over the country, and its efforts have been so ably seconded by the can- tonal natural history societies that the most important of these silenfc witnesses to ancient glacial action have been carefully sought out and protected from destruction. The geologists of France have, as we intimated some time ago, lately awakened to the necessity of making a similar provision for the numeraus erratic masses in the departments adjoining the Vosges, the Alps, and the Pyrenees, many of the most valuable of which have already been appropriated for building or other purposes. It is but lately that the immensity of the glacial action in eastern France has been comprehended. For the past ten years the two geologist:^, MM. Falsan and Chantre, have been occupied in a thorough study of the great movements which once took place in the valley of the Rhone. Their results are embodied in six large maps, on a scale ' of an inch to the mile, which give a careful reproduction of the strix, marking the progress of glaciers over the rocks in the valley of the Rhone. From their investigations it appears that the ice in the neighbourhood of Grenoble possessed a thickness of over 3,000 feet, and that the glacier formed an enormous fan-shaped mass, bounded on one side by the alps of Savoy and Dauphine, and on the other by the mountain ranges of Beaujolais and Lyonnais, and extended beyond Thodure. For the careful mapping of the movements of the Rhone glacier not only the abundant heaps of pebbles and the striae have rendered the .chief service, the erratic blocks have at every stage played a most important role ; and it is to be hoped that the efforts now set on foot will preserve to coming geologists the means of thoroughly tracing the paths of the great glaciers in other parts of the country. In the last Annual Report of the Prussian Commission for the Scientific Examination of the German Sea-coast, we notice an interesting comparison of the relative results obtained from equal areas of (i) fish ponds, {2) grazing districts in Schleswig- Holstein, and (3) fishing grounds off Hela. The latter covered a surface of 7,200 hectares, and supplied, in the course of a year, 456, 000" pounds of fish as the result of 3,405 expeditions. As contrasted with each other, per hectare, the land yielded 167 lbs. of meat, the fish-pond yielded 153 lbs. of fish ; and the sea-fisheries yielded 63 lbs. of fish annually. This is the first effort to establish a comparative estimate of the value of fisheries, and affords some idea of the sources of wealth at the disposal of maritime nations, even when contrasted with the adjoining land. The Geographical Society of Vienna has conferred the title of honorary member upon Prof. A. Bastian and Dr. Brehm. On May 16 a meeting of friends of natural history was held at Dresden, when a resolution was passed to found a society for the establishment and maintenance of an aquarium in that city. The Electricite, a scientific paper which was started two years ago by Count Ilalley DaiToz for promoting a special electrical exhibition, will resuue its publication on July I next, to promote a similar project to be executed at the Paris Palais de 1' Industrie in 1879. A NEW work on Russia, entitled " Dasmalerische Russland," is about to be published by B. M. Wolff, of St. Petersburg. The editor is Herr P. Semenow, Chief of the Russian Statistical Department. The work will consist of four volumes, and will contain over 500 illustrations. M. DE FoNViELLE Writes that he has learned by private letter from Philadelphia, and from a design published by the A^^ York Daily Graphic that Prof. Ritchel succeeded in directing balloons in the interior of the permanent exhibition building on May 22 last. About the same time M. de Fonvielle witnessed an experi- ment by Capt. Annibal Ardisson in the Paris hippodrome, which June 20, 1878] NATURE 207 was successful also so far as demonstratinj the possibility of motion ; but the apparatus was so imperfect that the balloon moved very slowly indeed, and another apparatus has to be made by the French experimentor. Instead of using common lighting gas, Prof. Ritchel resorted to pure hydrogen. His balloon had only 3,000 cubic feet measurement whilst Capt. A rdisson's wanted about ll,oco. Capt. Ardifson's motor was composed of two very imperfect fans worked with the hand. Prof. Ritchel used a screw propeller moved with both feet, so that he had his hands free for working a horizontal fan, for ascending and descending at pleasure. Instead of constructing a spherical balloon. Prof. Ritchel had prepared a cylindrical one similar to the balloon Delamare tried fifteen years ago without succes, in the open air. It is stated that Prof. Ritchel's success was very great, and the experiment will be tried again in Phila- delphia, and probably soon in Pari«. These experiments, M. de Fonvielle thinks, disprove the scheme advocated by the head of the French balloon service. Col. Laussedat, who, in a paper recently referred to in Nature, suggested that the motive power should be applied to the balloon instead of being annexed to the car. A VALUABLE sketch of the development of the natural sciences in Holland, has lately appeared in Leydea from the pen of Dr. B. van Haan. The late investigations of Count Wurnbrand, en the loess formations of the Danube in Moravia, lead him to the opinion that these deposits are entirely of an alluvial origin, and not due to diluvial disturbance^. A large variety of fragments of char- coal, carved bits of bone and horn, flints, &c., accompanying the collections of animal remains found in the e strata, point with great certainty to the existence of mankind at the time of their formation. An interesting archa:ological discovery is chronicled by the Berne papers. A forest in the neighbourhood is found to grow above a biuried Roman town. Numerous edifices have been laid bare, and the various remains which have been unearthed show it to have teen inhabited by the officers of the Roman forces, who occupied the strong defensive positions on the river Aar. Among the more important- scientific novelties in the German book trade during the past month, we notice the following works : — " Die Dolomit-Riffe von Sudtirol und Venetien," iste Lief., Dr. E. von Mogsisovics (Vienna) ; " Die Reptilien und Fische der bohmischen Kreideformation," Prof. A. Frie (Prague) ; "Die Erdrinde und ihre Biliiung," J. Lippert (Prague) ; " Vortrage iiber Geologic," F. Henrich (Wiesbaden); "Die Geologic und ihre' Anwendung auf die Kenntniss der Boden- beschaifenheit der oesterr. -ungar. Monarchie," F. von Hauer (Vienna); " Exkursionsflora fiir Mittel- und Norddeutschland," Exknrsionsflora fiir Suddeutschland," Dr. M. Seubert (Stutt- gart); " Taschenbuch der deutschen und schweizer Flora," E. Hallier (Leipzig) ; "Flora von Deutschland," Prof. A. Garcke (Berlin) ; " Die Schule der Physik," J. Miiller (Brunswick) ; "Grundziige der Elektricitatslehre," W. von Beetz (Stuttgart); "Lehrbuch der Physik," F. J. Pisko (Briinn); "Sonne und Monde als Bildner der Erdschale," J. H. Schmick (Leipzig) ; " Ueber Meerstromungen," E. Witte (Pless) ; " Anleitung zum Experimentiren bei Vorlesungen iiber anorganische C hemic," Prof. K. Heumann, III. (Brunswick) ; " Anleitung z;ir quanti- tativen chemischen Analyse," Prof. C. R. Freseni;i«, II. 2 (Brunswick). \ye have upon oiu: table the following books: — "Outlines ■, of Physiology," by Dr. McKendrick (Maclehose, Glasgow); "Choice and Chance," third edition, by W. A. Whitworth, M.A. (Deighton, Bell, and Co., Cambridge) ; "A Library Map ;- of London and its Suburbs," by J. B. Jordan (Stanford); "A Geological Map of England," by Prof. Ramsay (Stanford)' "A Geological Map of Ireland," by Prof. E, Hull (Stanford) ; "Grundziige der Electricitatslehre," by Dr. W. von Bertz (Stuttgart) ; "A Candid Examination of Theism," by Physicus (Triibner and Co.); "A School Flora," by Dr. Marshall Watts (Warne and Co.). The additions to the Zoological Society's Gardens during the past week include a Black-faced Spider Monkey (Ateles ater) from East Peru, an Ocelot {Felis pardalis), a West Indian Rail {Aremuies cayennensis), a Black Tortoise {Testudo carbonaria), a Common Boa {Boa constrictor) from South America, presented by Capt. J. Moir; a Himalayan Bear (C/rsus tibetanus), aii Indian Crow (Corvus splendcns) from India, presented by Capt. J. S. Murray; a Rufous Rat Kangaroo {Hypsiprymnus ru^es- cens) from New South Wales, presented by Mr. Thos. Wick- enden ; Six Herring Gulls {Lams argentatus) European, pre- sented by Mr. Arthur Clarke ; two Black-crested Cardinals- {Gubernatiix cristaielld) from South America, aii American Thrush (Turdus migratorius) from North America, presented by Mrs. Arabin ; a Black Saki {Pithecia satanas) from the Lower Amazons, a Spotted Cavy {Ccelogenys paca), a White Ibis [Ibis alba) from South America, purchased ; a Chimpanzee ( Troglodytes niger) from West Africa, deposited ; a Reeves's Muntjac {Cerz/ulus reez'esii) born, six Upland Geese (Bemicla magillanica), a Brazilian Teal {Querquednla brasiliensis) bred in the Gardens. THE MICROPHONE^ A LATE member of the pre.-ent ministry, at a dinner given ■^ by the institution whose hospitality we experience in this hall, implied, on the authority of one of the leading members of the engineering profession, that invention, like cocktails and Colorado beetles, had taken root in America and had deserted old England. It is therefore to me, as I am sure it is to you» a great gratification to have brought before us an invention which is the offspring of British soiL During the last few months the science of acoustics has made marvellous and rapid strides. First of all we had the telephone, which enabled us to transmit human speech to distances far beyond the reach of the ear and the eye. Then we had the phonograph, which enabled us to- reproduce sounds uttered at any place and at any time ; and now we have that still more wonderful instrument, which not only enables us to hear sounds that would otherwise be inaudible, but also enables us to magnify sounds that are audible ; in other words, the instrument which I shall have the pleasure of bring- '\a.'y before you to-night, is one that acts towards the ear in the same capacity as the microscope acts towards the eye. I may point out, in the first instance, that the telephone and the phonograph depend essentially upon the fact — and a great fact it is — thit the mere vibration of a diaphragm can reproduce all the tones of the human voice. In the telephone the voice is also made to vibrate a diaphragm, which, by completing an electric circuit, or by varying a magnetic field, or by altering the resistance or electromotive force of the circuit, produces effects at a distance which result in the reproduction of the motion of the diaphragm. Bat in this new instrument diaphragms are cast aside, and we have the direct conversion of sonorous vibrations, or sound waves, into forms of electrical action. Now, if it had been the habit or the custom of this Society to give to the papers and discussions delivered here sensational titles, I should have been inclined to call the few remarks I am going to make to-night, "A Philosopher Unearthed." Prof. Hughes is well known to us all ; he has been more or less asso- ciated with this Society since its first inception. Whenever he is in London he is amongst us. His instrument is well known to us as one of the most exquisite pieces of mechanism ever in- vented ; and his works, though few, are known because they are sound. ITie chief characteristic of this philosopher whom I have succeeded in unearthing, is his extreme modesty. If he had been left to himself, I do not think we should ever have had the microphone here ; but, by a lucky chance, he admitted me into his secret, and following, as I have done, all his steps, I am I A lecture given before the Society of Telegraph Engineers, on May 23, by W. H. Preece, V.ce-President Soc. T.E., Memb. Inst. CE., &c., &ci 208 NATURE \yu7ie 20, 1878 CQabled to-night to bring before you the results of his labours, and they have been labours indeed. For months and months he has been working and straining at the ideas which at last he has •elaborated into the microphone. Now the chief characteristic of the apparatus I am going to introduce to you to-night is its great homeliness, its uncouth roughness, and its absurd simplicity. With common nails, with small pieces of wood, with halfpenny money-boxes, with plain sealing-wax, with the ordinary apparatus which every child has at its command, he has been able to attack nature in her strong- hold— to ask her questions and receive back answers, and lay bare to us facts and thoughts which, though they have existed from time immemorial, are brought to light now for the first time. Now, let us in the first place ask ourselves this question : What is sound ? It is a very difficult question to answer in the short time at my disposal ; but it is necessary that I should first say something to you about the nature of sound, and then say something about the nature of electricity, and show you how the one can be converted into the other. Now, what is sound? While I am speaking to you I am setting the air in this room into vibration. The air of this room is composed of an infinite number of infinitely small molecules ; every molecule is set in motion, and vibrates to and fro, back- wards and forwards, like the bob of a pendulum, and between my mouth and every one of the ears in this hall there is a rapid but short excursion to and fro of every single molecule that comprises the atmosphere of this room ; and it is the impinging of these molecules against the drum of the ear that produces that sensation called sound. But more than that, not only is the air of this room in this marvellous state of motion, but every piece of wood, every wall, every picture, everything in this hall at this moment, is almost, I may say, alive, trembling away, moving backwards and forwards, forming what are called sono- rous vibrations. If the sound be loud enough, and the note deep enough, we can distinctly feel these vibrations. Sound is therefore the vibration in particular periods and particular phases of matter. Now what is electricity ? Faraday, the greatest electrician perhaps that ever lived, was asked that question, and he said the more he studied electricity, the more he unravelled its mysteries, the more mystified he became as to its cause and its origin ; therefore it seems an act of impudence on my part or the part of any one else to attempt to answer the question. What is electri- city? But great strides have been made since the days of Faraday ; we know a greal: deal mer* now of the internal mole- cular action of bodies ; we know that light, and heat, and sound are the mere action of those molecules of which matter is composed, and we feel sure, from the facts brought to our notice by the delicate apparatus of the present day, that electri- city is simply a mode of motion, nothing more or less than the simple play of the molecules of matter. The truth of this will be made evident to-night by the wonderful connection which exists between sound — which we know to be a mere mode of vibration — and electricity, which will reproduce to us the effects of sound. To make this evident to us we must have a detector which will render apparent to us any electrical action that shall result in sound, and it fortunately happens that this marvellous telephone is an instrument of such ex- treme delicacy that it has made us acquainted with currents of electricity hitherto unknown, though their presence has been suspected. The telephone which Prof. Hughes has employed in his researches is as simple in its construction as all his other apparatus. It consists of two rough pieces of board clamped together. There is half the coil of an electro-magnet that probably has been in his possession since his early experiments to judge from its appearance. The magnet is a piece of steel rod that has been magnetized. The wire used, and which he has found extremely useful, is wire that was originally made for very different purposes, viz., for ladies' bonnets, and in front of this is placed a piece of ferrotype iron, well-known by those who have experimented with the telephone. But what is the source of sound ? It was necessary in making these experiments that he should have a source of sound. His source of sound was a small mantelpiece clock of French manufacture, which cost originally three or four francs. It has been in use many years, and has been in many parts of the world. It is repaired with great lumps of sealing- wax, but nevertheless it has, or ought to have, a pendulum, which gives a succession of beat?, and those beats form a source of sound. Now, with this source of sound, and his beautiful scientific apparatus or detector, he started upon one of Sir Wm. Thomson's discoveries, viz., that wires alter their electrical condition when they are placed under strain. He took a piece of wire, applied weight to it, connected the clock with it, and heard nothing. He was not disconcerted, he applied weight after weight till he reached the breaking strain of the wire, and at the moment when the wire broke, he heard a rush or sound which he thought was an indication of what he was searching for, so he took the two ends of his wire and laid them together, placed his source of sound above them, and to his intense delight heard — what imagination perhaps assisted him in believing to be — a tick. He thought he was on the right track, and he then manufactured with a flat piece of brass for a lever, a pin for an axle, sealing wax for cement, and black wax for solder, and the uncovered bonnet wire for binding, a little apparatus which enabled him to apply constant pressure to the thing he was experimenting upon ; in fact, by this means, he was enabled to produce what electricians call a "bad joint." To his intense delight he found that with this bad joint he was able to obtain sonorous effects. But this contrivance, simple as it a ■•pears, was a great deal too elaborate and complicated for his purpose, so he took two little nails — the little bright nails so much used in France — laid them side by side, not touching each other, and bringing the ends of the wire in contact with them, and laying between, or across them, a third and similar nail, he was able to reproduce, almost perfectly, the sound of the clock, and more than that he began to get indications of the sound or tone of the voice. He then useti chains ; he took my gold chain and put it beneath his little compressor, and with that we were able to speak with great ease. From that he tried filings, and found with matter in a finely divided state, that -he was able to reproduce all effects of sound. At last he made little glass tubes about two inches long, filling them with white bronze powder which artists use, which is a mixture of zinc and tin, and he was able to exactly reproduce the tones of the voice. But in his experiments with carbon he was able to make what may be called quite an independent discovery. The carbon he experimented with was the common carbon used by artists in sketching their drawings, and this cai-bon he found to be a non-conductor of electricity. The idea struck him that this non-conductor of electricity might be made a conductor, and by various processes he at last arrived at a plan of boiling or heating this carbon in quicksilver. Carbon so heated in an atmosphere of quicksilver itself becomes permeated through and through with quicksilver, and by that means we get the mercury subdivided into an infinitely fine state. Probably mercury in this state as closely approaches the molecular as anything can do. Fig. I. There is no apparent indication of mercury"under the micro- scope, and yet we know that the carbon has been mercurised, because it is converted from a complete insulator into a con- ductor, and it has a metallic ring when it falls. Now then, having by these processes arrived at a substance which is remark- ably sensitive to all the variations of the sound of the human voice, his next task was to construct these things into such a form as to make them telephonic transmitters. For that purpose he brought to his aid a very cheap kind of apparatus, a half- penny money-box ;- inside this he placed his carbon transmitter, and as this discovery is not fenced in by fear of the patent or any other law, I am quite sure you will be glad to know how to make a Hughes transmitter. First he takes a piece of quarter- inch board about two inches long and one inch broad, and he raises upon that two thin brass bearings with a hole worked through by means of a pin for the support of the axis. He then takes a piece of carbon which has been mercurized about two inches long, which has a pin cemented to it near its centre, and which acts as an axis, and makes it into a lever. On the board he places a small piece of carbon, similarly treated, and upon this rests another similar sized piece of caibon, the two being con- nected by a piece of paper. This is the end of one wire, and that the end of another wire; and on this diagram the arrangements of the circuit yune 20, 1878] NATURE 2C9 are shown, s represents the source of sound, which I have shown on the black board, u represents the battery, and T the telephone. Now the battery is another remarkable speci- FlG. 2. men of scientific manufacture. Three little glass tumblers are taken ; at the bottom of each a coil of copper wire is coiled spirally. The copper wire is covered with a little sulphate of copper. The tumbler is then filled with moistened clay, and upon the top of the clay is placed a piece of scrap zinc. The three cells are placed in a cigar-box. s is what is called the box- transmitter. The tube-transmitter is shown on this diagram. ^AA..^^^^ -^.-^ S-^ Fig. 3. A is a glass tube [about two inches long, and one quarter inch in diameter, inside which several pieces of mercurised carbon are inserted, touching each other with a pressure regulated by a screw fixed to each end. In that drawing there are six pieces of carbon, acting in this little transmitter ; here (pointing) there are seven or eight, but that makes little difference, and the size of the carbon appears to be of little consequence. He has produced effects with carbon not larger than a pin's head. We shall show this by and by, but rather than disturb the order of these researches, I think it advisable in the next place to show you how this principle has been carried a little farther to pro- duce what he calls the "microphone." This apparatus, drawn upon the board, is extremely sensitive. It will give evidence of nearly every sound ; but in the microphone itself, which I have here, this extreme sensitiveness is carried to a still fiurther extent. In point of fact, this is a microphone; but in this particular instance the pressure bearing between the two carbons is regulated by a spring fixed in this way, and it is so regulated that the transmitter is independent of any position in which it may be held. It is free to be moved in any direc- tion in consequence of the pressure of the spring, but in one form of instrument this spring is dispensed with, and the pressure between the carbons is reduced to its greatest sensi- tiveness by making the two arms of this lever as short as pos- sible. In the first machine he used, a piece of carbon was fixed on the top of an upright board, and a smaller piece was fixed down below. A cup-shaped hole was made in the upper piece of carbon, and a similar one in the bottom piece. Resting in these holes was a lozenge-shaped piece of carbon ; and this lozenge-shaped piece of carbon rests with the greatest nicety upon its lower support, and is just in that position of equili- brium that the slightest atmospheric disturbance produces the effects which we are now about to show you. I think it desirable to tell you that you must not to-night expect distinct articulation. We have made a violent effort to make these experiments evident to you all. (Illustrations were given of speaking, singing, &c., &c.) Now, the effects you have just heard have been produced by a transmitter similar to that drawn on the board. We will now repeat the effects with the machine on the table ; and in order that you may judge of the effect — for Prof. Hughes desires that you should see there is no deception — we will connect this up, and use his old friend the clock to make its ticks,* if it will, evident over the whole room. One of the greatest effects which this instrument produces is to render evident the tramp of a fly ; and we have some nice little captives with which we will demon- strate that effect at the close of the meeting. (Illustration with clock.) To show that that is not due to the clock itself. Prof. Hughes will lift up the clock, when all traces of sound will have disappeared, and on putting it down again the sounds will be produced ; so that the sound you hear is the sound of that clock which has been magnified. (This was so.) Now, we have here a common quill pen, and Prof. Hughes will do as they do on the stage, pretend to write a letter ; and I have no doubt if you listen attentively you will hear the scratch- ing of his pen. (Illustrated.) There are some peculiarities in this apparatus that are very striking. In the first place, though the sounds produced are very great, they do not interfere with each other. If you have a friend at the other end speaking to you, you can hear his voice distinctly working through your voice ; and the result is you get a duplex action. Two or three persons can talk to each other without impediment or confusion. Yet another point is, that the articulation is absolutely perfect. One of the great difficulties, both in the telephone and the phonograph, is getting the sibilant sounds reproduced — such as "s," and '•c,"and "sh," &c., which are produced by such extremely minute variations of the sonorous vibrations that they are lost in those instruments. Thus, if through the telephone you ask a person to "waltz," it will come out "walk," and names like my own, with the sound of "s" in it, would come out " Pree," not " Preece." In this transmitter one of its chief peculiarities is the fact that all sounds are faithfully reproduced ; and it tends very much to upset the notion — Helmholtz's theory — that vowel sounds and other sounds are due to the superposition of waves upon waves of tones and over-tones. This apparatus shows almost unquestionably all these different properties ; all these effects of intonation are due to differences in the form of the curve sent. Another peculiarity is this. I have told you that all in this room, every one's body while I am speaking, is alive with sound. If you take this transmitter and place it in front of your mouth, or put it on your forehead, or on the top of your head, or put it into your pocket, or upon your breast, it will still transmit sounds to distant places. Put it in a room, it does not matter where, it will reproduce the sounds. Put it anywhere in a drawing-room where there is a piano, you will hear the sounds of the piano faithfully reproduced. It is as you see a marvellously rough affair. You may throw it up, kick it about, or do what you like with it, it will always act. Here is the identical box that Prof. Hughes made two or three months ago. It has never been touched, it has been always at work, and never needs repair. These are some of the peculiarities of his instrument, and I daresay some of you would-like to know a little about its theory. We have here two points in contact, and those two points in contact complete an electrical circuit. The electric current that flows through that circuit depends for its strength entirely upon the obstacles or resistance in that circuit to the flow of the current ; an alteration in any shape or form in the resistance of that circuit will result in the increase or decrease of the strength of the current flowing, and upon this diagram I have made a rough attempt to give you an idea of what occurs. \J^JjJjjjjJ^jj Fl5. 4. You must not conceive these round balls are molecules them- selves, they are merely meant to represent the sphere of action of each molecule. In a normal state the molecules rest against each other, as shown by the upper hne. When fi-om any cause pressure is increased, they are contracted, as shown in the second line ; when from any cause the pressure is decreased they ex- pand, in the form shown on the other line. While I speak to you, the air of this room is thrown into vibration, the mass of air being subdivided into molecules in compression and mole- cules in extension. In a long wire these successions of com- pressions and extensions compensate each other ; but when we break up a body into infinitely small parts, when we make less contact between tv.o bodies, as shown there, and isolate the 2IO NATURE [June 20, 1878 portion of the sonorous wave in conipre sion from that in ex- tension, the result is that we have a variation in the resistance of the line. Now this variation in resistance depends upon the compression and dilatation of the molecules. They depend upon the tone of the voice, and the result is the resistance of the current varies with its variation of pressure, and at the distant end we have currents varying exactly as the voice varies, and reproducing on the telephone all the effects which we have seen. Hence follows the action of the microphone, and the action of the transmitter is one which depends upon the variation produced in bodies by the sonorous vibrations of the voice. As I am now speaking at that telephone, all the molecules of that trans- mitter are thrown into this elaborate series of CDmpressions and dilatations. The current is varied ; it goes to the room below, and is reproduced upon the telephone, as we have heard. Hence the effect is due to the difference of presfure, as is proved by using atmospheric pressure, and applying heat ; and any large increase of pressure results in sound bemg reproduced. No one has ever been nearer a great discovery than Mr. Edison. His telephone is based on the variation of resistance due to pressure. He used carbon and finely divided matter, but he worked on the idea that the difference in pressure was produced by the vibrations of a diaphragm. Hcd he thrown away his diaphragm he would have forestal'ed Prof. Hughes in this respect, and found that the sonorous vibrations themselves produced this difference of pressure. The great secret of Prof. Hughes's discovery is that sonorous vibrations and electrical waves are to a certain extent synonymou*. Now as to the uses to which this instrument is capable of being applied. It has been applied to surgical purposes in the form of the stethoscope. Though it does not show very markedly the beats of the heart, because they are more mechanical thumps than sonorous vibrations, yet it will show the injection and ejection of air in the lungs, and for many other surgical purposes it must become a valuable instrument. It admits us to some of the mysteries of insect life, and by its means we can hear sounds emitted by insects which have never been heard before. Going further it has enabled the deaf to hear ; deaf persons who never heard a telephone before have been able to hear distinctly. It has enabled us to hear the physical operation which goes on in the process of crystalliza- tion of bodies and other things which before were wholly in- audible ; and in fact it is impossible to say to what uses it may not be put. It is rather remarkable that in an excellent paper read before the American Electrical Society, the author, Mr. Pope, makes these curious remarks : — " The most striking results are to be looked for in the direction first pointed out by Mr. Gray, for the reason that if an effectual method of controlling the resistance of the circuit by means of atmospheric vibrations can be discovered, the source of power, which in this case is the battery, may be augmented to any re- quired extent. It is not to be denied that the problem thus presented is one of exceeding mechanical difficulty, but there is no reason to suppose that it may not be successfully solved. It is to the development of this variety of the speaking telephone rather than to that of the magneto instrument that inventors will find it most advantageous to turn their attention, for I hazard little in saying that the latter has already reached such a surprising degree of efficiency, as to leave comparatively little more to be done within the necessary limitations which have been pointed out." Mr. Pope throws out what has been done with the exception of the supposed mechanical difficulty, and that has been got over by a halfpenny money-box. Now one very pleasing and gratifying circumstance attaches to this discovery of Prof. Hughes : he has thrown it open to the world, and by that means he has no doubt checked that species of immorality — I don't know what else to call it— connected with the infringement of the patent law, as regards the tele- phor.e. He allows us all to manufacture microphones for our- selves, Vut even he has been subjected to rather a peculiar inci- dent. One impulsive and active gentleman who was present at the Royal Society the other night when Prof. Hughes first described his invention, went home and made himself a micro- phone, wrote a description of it and sent it off post haste to Paris. A short time afterwards Prof. Hughes himself with great care prepared a paper to be read before the French Academy, but to his great surprise he found that he had been forestalled, a description of his instrument had already appeared in the Paris prints from the gentleman in question. There are lessons to be learnt from this discovery, and the principal lesson is — we can all of us with the means at our disposal cross-question nature and find out her secret?, and there are many secrets which yet remain to be divulged. We learn the wonderful connection which exists between all the physical forces : heat, and light, and electricity, and magnetism, are all CO -related, and it has come to this, that what boys have said in joke has come to pass in earnest. We have been able to con- vert electricity into light, and light into electricity. We are now able tO' convert electricity into sound, and sound into electricity, and thus we are enabled to see the thunder and to hear the lightning. THE SCIENTIFIC AIMS AND ACHIEVE- MENTS OF CHEMISTRY^ A/TORE than a generation has passed away since my predc ^^ cesser in the chair of Chemistry, Prof. Bischof, who was so full of merit in the domain of chemical geology, held the high office which the friendly confidence of my colleagues has entrusted to me for the ensuing university year. Since that time chemistry has undergone important changes, and its position upon the German high schools has also become an essentially different one. At that time a general discouragement had takei root amongst the most eminent chemists. It was believed that all speculation had to be dismissed from the field of chemistry, and particularly that all atomistic considerations had to be discon- tinued, because whole categories of facts could not be made to agree either amongst each other, nor with the general theoretical views of that time. At our high schools at that tima chemistry was only taught from the chair ; very often by teachers who were essentially appointed for other subjects. At most of the universities the students could be admitted to practical work only by favour of the teachers, and even Liebig's laboratory at Giessen, the first of all educational laboratories, only just then received its interior arrangement. How different now ! Well aware of its task and its aim?, scientific chemistry, in close connection with physics, advances slowly, it is true, but with self-reliance and a certain confidence. Each university has its special chair of chemistry, many indeed have several. Richly furnished laboratories, and very often luxurious edifices, are at the disposal of chemical students in nearly all German universities, and the chemical lectures are the best frequented ones almost everywhere. All this and also the circumstance that it is just a chemist who is able to day, as a representative of the entire university, to speak to the entire university from this place, proves, doubtless, that our science is now generally recognised to the extent it merits. But as on many sides it is over-estimated, it is yet more frequent, on the other hand, that its scientific right of existence is doubted. While outsiders who may occasionally have seen a chemical experi- ment, or may have heard of the grand applications of chemistry to practice, declare chemistry to be the finest science of all, although they may not be able to form an idea concerning its scientific aims, other one-sided representatives of so-called humanistic studies, who also mix up the applications of chemist(y with its scientific task, tend towards the unjustifiable view that chemistry ought really to be taught only at polytechnic schools, but not at the "universitas litterarum." The propagation of such erroneous conceptions renders it the duty of the chemi.t to appear as the defender of the science be represents, and it will doubtless be considered fully justified if to-day I try to explain to you the scientific position of chemistry and its participation in the great progress of universal science. Chemistry has often been designated as the sister of physics, and both subjects are in reality so nearly related, their dornains are so contiguous, that the layman cannot understand the differ- ence, and that even the scientific man can hardly fix the limits. Chemistry and physics together form that group which may be designated as general natural science, inasmuch as the occur- rence of their materials of study is unessential, and the laws recognised by them are valid everywhere. Astronomy, geo- graphy, geology, botany, and zoology (the latter including those more special subjects treating of man, and which form the scientific part of medicine), all these, which ought to be comprised under the I Address delivered on a'sum'ng the Rectorate of the Rhenish Friedr.'ch- Wjlhelms University of Bjnn, October 18, 1877, by Prof. Aug. KeKule. June 20, 1878] NATURE 211 name of special natural scUme, are tied to certain circles of objects of study, and the truths they have established are valid only for these circles. Even that generalisation of the so-called organic natural sciences, which is designated as biology, cannot very well be called a general natural science, because if indeed anywhere else than upon the earth there exists something similar to what we call life here, there is yet but little pro- bability that the laws of terrestrial life may be applied to that life of other worlds. The common task of general natural science — of physics and chemistry, therefore — is the investigation of matter, of its pro- perties, its changes, and of the laws of these changes ; and the laws recognised by them must be applicable wherever there is matter at all. Now with regard to the difference between physics and cheniis- try, it strikes the superficial observer that modern physics treat?, in a more general manner, of the properties and changes of properties of bodies, and in doing so that it contemplates the separate bodies only as the bearers of the properties ; while chemistry studies the separate bodies differing with regard to their material, and that it touches their properties only inasmuch as they appear necessary for distinguishing the bodies. One might be inclined to found a definition of the two disciplines upon these difference?. But when we enter more deeply into the subject we shall see that the essential differences must be looked for elsewhere. Of all conceptions which the human mind could form regarding the essence of matter, only the hypothesis of discrete mass- particles, the atomistic hypothesis therefore, has led to an intel- ligible explanation of facts. Even if nobody who has followed the scientific discussions of the latest time, can deny that the tendency of natural scientific reflection just now again lies in the direction of reducing the differences of materiSs to dynamic causes, yet we must certainly own that at present the observed facts can be deduced as necessary consequences from the atomistic theory only. On this point physicists and chemists are no doubt agreed. And if even modern representatives of speculative philosophy concur in the view that all natural knowledge leads to the mechanics of atoms in the last instance, then we may doubtless use the atomistic theory preliminarily as the basis of further reflections in the domain of natural science and, for the present at hast, found upon it the definition of the separate branches of natural science, be it on'y in order to render a clearer account to ourselves of their tenour and of the limits of their domains. Now the sum total of all knowledge obtained with regard to matter has led to the following maxims of ths atomistic theory. We must imagine that matter consis's of small particles, uniform in their material and not further divisible, not even by chemical processes, — of atoms. These atoms accumulate in consequence of forces inherent in them or acting upon them, and thus produce systems of atoms, or jnolecules. In the gaseous state these mole- cules move about in space as isolated beings, in the o'.her aggre- gate states an attraction of molecules also becomes apparent, and thus the masses originate which are able to act upon our senses directly. If this conception of the essence of matter is taken as a basis then we may define chemistry as ths science of atoms, and physics as the science of molecules, and it lies near then to look upon that part of modern physics which treats of masses as a separate discipline, and to reserve for it the name of mechanics. Thus mechanics appears as the fundamental science of physics and chemistry, inasmuch as both are obliged to treat their moleo«les cr atoms respectively as masses in certain considerations, and particularly in calculations. Mechanics, physics, and chemistry, however, are the bases of all special natural sciences, because it is evident that all changes, no matter whether they occar, in the great cosmos, or in the microcosmos of the ve^^etable or animal body, can but be of a mechanical, physical, or chemical nature. Now from the fact that chemistry has to do with the study of atoms, of the building stone-, the.efore, of which ths molecules are constructed which physics treats as a whole, it results directly that the theoretical investigations of chemistry offer more diffi- culties than those of physics, and that theoretical chemistry can progress in certain directions only after theoretical-physical knowledge has sufficiently advanced. The comparatively low state of theoretical chemistry thus seems not only pardonable but natural, and it becomes clear why for the present theoretical- chemical investigation has principally turned its attention to those . questions which are more or less independent of physics. Thus we understand why chemical dynamics is as yet an alm:st uncul- tivated field upon which the mittrlals, which are heaped up in immense profusion could, up to the present, not find a theoretical treatment, while on the domain of chemical statics ripe, or at least partly-developed fruits, were reaped in plentiful quantity. It will not be difticult to show that chemistry and chemists have, in this direction, materially contributed towards the progress of the general doctrine of atoms, therefore towards the progress of our knowledge of the nature of matter. Since the (as far as we know) first foundations of the scientific observation of nature were laid by Democritus, the most ele- mentary maxims of the theory of matter have remained the same. " From nothing nothing can come ; nothing that is can be anni- hilated; all change is only combination or separation of par- ticles." But the atomistic theory of antiquity was more a precursor of the views which we now designate in physics as the molecular theory ; it contained, even in its further development, no fundamental thought of a specially chemical theory. The first fundamental maxim of scientific chemistry was pro- nounced towards the end of the seventeenth century by the chemist Boyle, who was first to define the conception of the chemical element as that which is not further divisible into ma- terially different parts. It will not matter whether many or perhaps all the bodies which we now consider to be chemical elments may be found to be further divisible in the progress of knowledge — although there is at present no real indication for this — the idea of the chemical element will always remain unaltered. With this idea of the chemical element that old conception of the indestructibility of matter was then connected, and thus the further fundamental maxim of chemistry originated, of the invariability of elements, which has not further been questioned since Lavoisier's celebrated experiments on the often- pretended change of water into earth, and which finds its confirmation in all chemical facts. From these views the chemical atom'c theory arose at the beginning of the nineteenth century, and the English chemist Dalton is with right regarded as its founder. While, after Democritus, the difference of all things is caused by the dif- ference of their atoms in number, size, shape, and order, a qualitative difference of atoms, however, does not exist, Dalton first in a definite manner supposed the existence of qualitatively different elementary atoms. He was first to ascribe to these qualitatively different atoms certain weights which are character' istic for the various elements ; he first showed that these relative atomic weis^hts may be determined by chemical study. As the conception of the chemical element so will also the conception of the chemical atom, as that quantity of elementary matter tvhlch is not furth:r divisible by chemical processes, remain for ever. For chemistry, the question whether the chemical atoms are originally units {einheitliche) and absolutely indivisible beings, is of no importance. Let the proof be given that the chemical atoms are formed of particles of a finer or Jer, or let the theory of revolving rings founded by Thomson, or some other similar conception which understands atoms to result from continuous matter, be proved in the progress of know- ledge, the conception of chemical atoms will not be altered or annihilated. The chemist will always welcome an explanation of his units, because chemistry requires atoms only as a starting point, not as an end. Dalton's atomic theory from the very first suffered from a certain imperfection which consisted in its speaking of the atoms of compound bodies as well as of those of elementary ones and thus did not distinguish the ideas of atom and molecule. For the first period, during which the foundations of chemical science had to be completed, no essential harm arose from this want of clearness, but later on, when the structure was to be developed farther, it caused considerable confusion. It is true that already in iSii Amadeo Avogadro pronounced the maxim that gaseous bodies contain an equal number of molecules in equal spaces, and that even the molecules of elementary substances consist of several atoms, and that in 181 4 the French physicist Ampere arrived at the same conclusions ; but this idea, which was so fertile in the future, hardly attracted any notice at first. In its application it led to contradictions which seemed insolvable at that time, and it was therefore aban- doned, although the great chemist Damas hai taken it for some time as the base of his considerations. More than that, it was forgotten until forty years later the Italian chemist Cannizzaro recalled to the memory of his colleagues the merits of his countryman. In the meantime chemists first, and later on physicists as ^^ell, 212 NA TURE Sjfune 20, 1878 had arrived at precisely the same conceptions, starting from new and perfectly independent points of view. The chemists, with Laurent and Gerhardt as leaders, were led by purely chemical considerations and essentially by reasons con- nected with systematics, to distinguish clearly between the ideas of atom and molecule, and to find methods which, in the perfec- tion at which they have now arrived, render possible the deter- mination of the relative weights of the atoms and molecules, and even of the absolute number of atoms in the molecules, for all more perfectly examined substances, by the discussion of purely chemical facts. Amongst others they arrived at the result that the molecule even of elements consists of two atoms as a rule. In physics, however, the mechanical heat theory caused a probability bordeiing upon certainty to be ascribed to the funda- mental thought of Avogadro's hypothesis ; and when our cele- brated colleague, Clausius, in the course of his classical investi- gations, had arrived at the conception that even in elements the molecules consisted of several atoms, then he could express his satisfaction regarding the fact that chemists before him, on totally different ways, had already arrived at the same results. After, in this manner, Avogaf^ro's hypothesis on the nature of gases had obtained general recognition, and the relative weights of the gas particles could thus be deduced from the specific gravities of gases ; after, on the other hand, we had learned to determine the relative weights of the chemical molecults by chemical c jnsiderations, then it appeared that both values were identical, and thus we arrived at the conception, which anyhow was probable on account of its simplicity, but which was not a necessary one previously, that the gas particles and the chemical molecules are identical, that heat therefore, is able to subdivide matter down to the chemical molecules. The chemical "^zx^. of the atomic theory was essentially extended some twenty years ago by that hypothesis, made by chemists, which has been designated as the theory of the chemical quanti- valence of atoms. In its fundamental thought this hypotheses only says that besides the characteristic atomic weight which is the cause that the elements combine in certain proportions of weight, the atoms still possess a further fundamental property, which causes them to combine exactly in those numbers in which they do. As we could not, at first, arrive at a clear conception of this fundamental property, we simply ascribed a certain num- ber of chemical attraction units to the materially different atom*:, and accordingly called them uni-, bi-, tri-, or quadrivalent. Now this hypothesis of the chemical quantivalence of ele- mentary atoms of course still offers many dark points, but yet it has led to the recognition of a law which, not only for chemistry, but for the entire atomic theory is of fundamental importance, and which chemists call the law of the connection of atoms ( Ver- kettung der Atome). The separate atoms of a molecule are not connected all with all, or all with one, but, on the contrary, tach one is connected only with one or with a few niighlouring atoms, just as in a chain link is connected with link. At the same time it is evident that the atoms within the mole- cules must be in constant motion, and if, indeed, nothing certain is known respecting the nature of this motion, yet it results from this very law of the connection that the intramolecular atomic motion must be of such a nature that the separate atoms move about certain positions of equilibrium without ever leaving them, as long as chemically the molecules continue to exist. The motion of atoms, therefore, is certainly similar to that of the molecules ia the solid state, and thus it may be said that the molecule: of existing substances are solid aggregations of atoms. A state of motion similar to that which the molecules of liquid bodies possess, occurs only with chemical changes, by which molecules of different atomic structure are formed, and then evi- dently only in a transitory manner and only for single atoms. A state of this kind doubtless plays an important part not only in fermentation phenomena, but also in the chemical processes occurring in living organisms. The nature of the motion of atoms is, as I said before, unknown at present. Perhaps it may be imagined as an oscillatory one in such a way that the nutnber of oscillations executed in the unit of time exactly represents the chemical value, and that atoms engaged in functional oscillation, and perhaps striking against each other, appear in chemical com- bination. Then the chemical quantivalence of atoms would have to be considered as a constant one with even greater probability than hitherto. Anyhow one might imagine that polyvalent atoms, at temperatures which, for the substances in question, might be called ultra-hot, do not meet with another atom during one or even more oscillation phases, while adding a part of their motion-energy to the molecular motion ; a conception which would correspond to the present conception of unsaturated affini- ties. We would have to think it probable, further, that upon raising the temperature still more, this intermediary state of partial dissociation would be followed by one of total dissocia- tion, during which isolated atoms move in space, just as has already been proved for mercury vapour at temperatures of easy access. The law of the connection of atoms based upon the hypothesis of chemical quantivalence, at present accounts cnly for the chemical serial connection (Aneinanderreihung) of atoms, without explaining their position in space and iheform of molecules caused by it. But even now, from investigations on molecular volumes it results that the nature of the connection of atoms influences the mean distances of atoms. The circumstance that with isomeric substances the boiling- point of that modification is the highest for which the law of the connection of atoms supposes a chain running in a straight line, while volatility increases the more ramifications the chain shows, the more compressed, therefore, the molecule appears- from a chemical point of view ; together with the maxim, pro- bable in itself, that the position of the point of gravity and the moment of inertia of the rotating molecule must be of influence upon volatility, seem to indicate that the views on the chemi- cal connection of atoms at the same time give us some notion on their mean position in space. The calculations made by Emit Meyer, of the molecular diameters, molecular transverse section?, and molecular volumes, also seem to support this view. Thus the probability of the hypothesis pronounced by Le Bel, and worked out further by Van't Hoff, of the unsymmetrical carbcnt, according to which the four affinity bonds of the carbon atoms, which had already been represented fetrahedrically, are imagined to exist in space in a tetrahedrical position, is in- creased. An hypothesis which may perhaps not merit the unconditional praise which Wislicenus has bestowed upon it, but which certainly much less deserves the bitter derision which Kolbe was inclined to throw upon it. The hypothesis of chemical quantivalence further leads to the supposition that also a considerably large number of single mole- cules may, through polyvalent atoms, combine to net-like, and if we like to say so, sponge-like masses, in order thus to produce those molecular masses which resist diffusion, and which, according to Graham's proposition, are called colloidal ones. The same hypothesis in the most natural manner leads to the view, already pronounced by our genial colleague, Pfluger, that such an accu- mulation of molecules may go further yet, and may thus form the elements of the form of living organisms. Of these mass- molecules we may perhaps suppose further that they, through the constant change of position of polyvalent atoms, show a constant change in the connected single molecules, so that the whole --and of course under generation of electricity— is in a sort of living state, particularly since, through the same change of position, adjacent molecules are drawn into the circle of combination and newly-formed ones are expelled. To follow such specu- lations any further at present would, however, be equivalent to- leaving the basis of facts rather too far behind us. Really fertile hypotheses on the nature of that force, which brings about the combination of atoms, have not been made up to- the present. The electro chemical theory, so ingeniously worked out by the great Berzeliu', of which, during whole decades, it was believed that it would lead to a satisfactory explanation of chemical facts and to their combination with physical phenomena, has proved completely insufiicient. In all probability in a future period of the development of science it will again be taken up, and will then, in a modernised form, bear its fruits. In any case besides the chemical quantivalence, which decides the number of combining atoms, the specific intensity with which this combinauon takes place, must aUo be considered. Here we must suppose that the atoms combined in a molecule, and there- fore saturated with regard to their quantivalence, do not only exercise an attraction upon each other but also upon the atoms of neighbouring molecules, and that thus a molecular attraction results, which is caused by the attraction of the separate atoms- and therefore depends on their quality. Only in this way we can explain the process of chemical decomposition and the exist- ence of that infinite number of more comphcated things which are supposed to be molecular additions or molecules of a higher order. Unquestionably the same cause plays a part in so-called mass-efficts and in catalytic decompositions. The formation of solutions must also be ascribed to it, which hitherto were consi- dered as chemical combinations ia varying proportions, but jfune 20, 1878] NATURE 213 which are now more appropriately called molecular mixtures. The same fundamental cause further gives rise to the phenomena of cohesion, adhesion, and capillary attraction, and it seems therefore as if the supposition of special molecular forces is in no way necessary any longer. Now as the attraction of atoms depends on their quality, it is also clear that the molecular attraction caused by such atomic attraction must,under favourable conditions, produce an orientation of all molecules combining with one another, and must thus lead to bodies of a regular molecular structure, therefore to crystals. Lastly, the question whether the properties of atoms are de- pendent on their ludght has much occupied the chemists of modern times. Positive results which could be rendered clear in a few words have not yet been obtained, but it seems, according to the observations made by Lothar Meyer and Mendelejeff, as if not only the chemical properties and specially the chemical quantivalence of atoms and the intensity of their mutual com- bination, but also the physical properties, which at present are ftill treated as constants for materially different objects, were a function and indeed a periodic function of the atomic weight. The mathematical form of this function is no doubt of a peculiar nature, but one thing seems certain, viz., that the numerical value of the atomic weight is the variable by which the substantial nature and all properties dependent on this are determined. Thus there again seems hope that it will be possible to reduce ail properties of matter, including gravity, to one and the same force. The right of introducing all such speculations into the do- main of exact science, has been questioned very much. It is generally conceded, indeed, that the setting-up of hypotheses on the domain accessible to exact investigation, as a method of investigation, is useful, inasmuch as it often may accelerate the progress of exact knowledge. But it is at the same time often believed that speculations beyond a certain limit are not admis- sible. ^The scientific value of all atomistic considerations particu- larly has ever, and also in the most recent time, been very much doubted. It has been pretended specially that the supposition of atoms did not explain any properties of bodies which had not first been ascribed to the atoms themselves. We must own that such remarks contain many truths, but just for that reason it seems necessary that we examine the limit of their correctness. It is generally acknowledged that the results of exact obser- vation have the value of facts, therefore possess that degree of certainty which human knowledge can attain at all. It is further not contested that to all those laws which, independent of hypo- theses on the nature of matter, are deduced from facts, nearly the same certainty must be ascribed as to facts themselves. It is just as incontestable, however, that the human mind in the positive understanding of facts does not find complete satis- faction, and that therefore natural sciences have to follow a yet farther and higher aim, that of the knowledge of the essence of matter and of the original connection of all phenomena. But the essence of matter is not accessible to any direct inves- tigation. We can only draw conclusions regarding it from the phenomena which are accessible to our observation. And thus it is evident that there is a certain limit which, moreover, is influenced by the state of our knowledge at any given time, beyond which positive investigation loses ground and where the path is only open for speculation. If, therefore, the single investigator, following the inclinations of his nature, rests satisfied with positive investigations and renounces all speculations, it is yet clear that to science as such this is not permitted. By way of hypothesis, based upon what is known as facts, ideas must be formed on the nature of matter ; the consequences of these ideas must be developed logically, and, if necessary, by the aid of calculation, and the results of these theories^must be compared with the phenomena accessible to observation." Of course, the complete truth will never be reached in this way, or there will, at least, never exist complete certainty that our conceptions are really identical with truth. But that conception which is simplest in itself, and which in the simplest manner accounts for the greatest number of phenomena, and finally for all, will have to be considered not only as the best and most probable one, but we shall have to designate it as relatiyely, and we may say, humanly, true- By this the scientific right of existence of speculative in- vestigation is no doubt proved, also for the so-called exact sciences, because beyond a certain limit these indeed cease to be «xact. Simultaneously, however,' the scientific value of the present atomic theory is also proved, because it has not been contested that, even in its present and still extremely incomplete form, it accounts satisfactorily for an uncommonly large number of facts, better than any other conception. It will certainly require further extension, and also a deeper fundamental structure ; but at present there is very little proba- bility that it will be completely superseded by essentiall;^ different conceptions. ' There are other reproaches which have been. made to chemistry specially, and still more to chem-sts, now and since the time of Lord Bacon ; and even chemists cannot deny that they were not altogether undeserved. It has been said that chemistry wilfully makes innumerable single hypotheses which are neither in connection with one another nor with the whole ; that the value of hypotheses is over-rated by her disciples, far to3 great certainty being ascribed even to such as are only little justifiable, and that they are treated as if they had been actually proved ; and finally, that her hypotheses are always gradually raised to articles of faith, and that everybody who sins against such dogmas is prosecuted as a heretic. Recent times have also, in this direction, brought about a considerable improvement. The justification and the value of hypotheses are now recognised in chemistry, but at the same time the true value of hypotheses is also understood by chemists. In chemistry also, as in all domains of science, blind faith in authorities has been crushed, and by this alone the danger of dogmatising is lessened. And should perhaps any one, who holds antiquated views, try to attach his dogma upon pro- gressing science as a restraint, he will always find the striving young generation, the representatives of the future, ready to remove unjustified impediments. If others, in the fiery zeal of youth, should be inclined to look upon daring flights of fancy as scientific hypotheses and to give them out as such, then those who are more moderate by themselves or by the riper experience of age, will always feel it a duty to step in as regulators. The school of independent, and at the sime time quiet thinkers, is now so numerously represented also among chemists, that a constant development of the science may be confidently expected, and an overgrowth of weeds need no longer be feared. Also in chemistry we are now well aware of the con- tinuity of human mental work ; the present generation no longer looks with despising contempt upon the work of their prede- cessors ; far from thinking themselves infallible, they know that at any time it remains to the future to continue the work of preceding generations. ON THE CA USES OF THE ASCENT OF SAP IN TREES ^ 'T'HE question as to what forces cause water to rise to such -'■ a remarkable height (frequently) in trees has had very various answers given to it. But these have mostly failed to account adequately for the phenomenon. Capillary action is perhaps the oldest cause adduced. The view was long popular that water rose in trees like oil in a wick, the connected vessels of the wood forming capillary tubes. This view lost force when it was known that the wood of coniferse was without vessels ; and it did not explain the weakening or stoppage of the rise of sap produced by amputation of the roots, nor the presence of air in the columns of sap. Shortly after Dutrochet's thorough study of difhision, this phenomenon was called in to account for the rise of sap. One grave objection to such a theory is the rapidity of the ascent of sap (it has been carefully measured) as compared with the slow- ness of diffusion, which depends simply on molecular motion ; another is the inevitable consumption of the osmetic force of tension. So that other problematical forces had to be called in. When Jamin found that the imbibition of water through fine porous substances {e.g. blocks of gypsum) took place with great force, and that the air could thus be compressed to several atmo- spheres, an effect of this nature was afhrmed to occur in living plants, the cell membrane being considered a porous substance. But in fact the natural saturated cell membrane has no air-filled pores, but only pores already filled with water, and even the hollow spaces, bounded by the cell membrane, are partly filled with water ; besides, the fact that a branch, immediately after being cut off, loses in great measure the power of raising water, is against this theory. ' Abstract of a recent paper In Der Naturforicher. 214 NATURE [Jtine 20, 1878 A few yeai-s ago yet another theory was started, based on M, Quincke's discovery of the tendency of liquid films to expand rapidly upon wetable surfaces. The only advantage of this lay in accounting for the rapidity of the rise of sap ; otherwise it was open to all the objections of the Jamin theory. A theory has lately been propounded, and thoroughly worked out, by M. Joseph Bohm, which is characterised by good con- sistency, and offers perhaps a more satisfactory explanation of the phenomenon than any that have been referred to. It is based, like the osmotic theory, on the cellular structure of all sap -conducting plants, and it attributes an important rdle to the elasticity of the cells. " When the surface-cells of a plant," says M. Bohm, "have lost a portion of their water through evapora- tion, they are somewhat compressed by the air-pressure. Like elastic bladders, however, they tend to take their original form. This of course is only possible by their drawing in either air or water from without. Since, however, moist membranes are little penetrable by air, the cells draw from cells further in a pjrtion of their liquid contents. These again borrow from their neighbours further down, which contain more water, and so on, either to the extreme root-cells or to those parts of the stem which are supplied with water from below through root- pressure." To illustrate the action M. Bohm constructed an artificial cell-chain. A funnel closed by a bladder represented the evaporating leaf ; to it were connected below several glass tubes about two ctm. wide, closed at one end with a bladder, and joined together in series by means of thick-walled caoutchouc- tubing. In consequence of the evaporation, the membrane which closes the funnel-mouth is bent inwards, and when it has reached a certain tension water is sucked into the funnel out of the next lower cell, which covers its loss in like manner. Manometers, connected with certain cells of the apparatus, indicate the amount of suction at different heights. To avoid fouling of the membranes carbolic acid was- mixed with the distilled water in the cells. Since bladder membranes, with a not very great height of liquid column over them, admit passage of water by filtration, these artificial cell-chains (it is pointed out) must act much more imperfectly than the sap- conducting cells placed over one another in living plants, which cells, by reason of their narrow aperture, retain their liquid column by capillary attraction. It is shown that this theory is in harmony with sundry pheno- mena which are contradictory of the imbibition theory. UNIVERSITY AND EDUCATIONAL INTELLIGENCE It will be proposed to confer the degree of D.C.L. honoris causa at the ensuing Oxford commemoration, upon Dr. William Spottiswoode, M.A., of Balliol College, F.R.S. The following awards for proficiency in Natural Science have been made at St. John's College, Cambridge : — Foundation Scholarships to F. J. Allen, Marr, Slater, C. M. Stuart ; Exhibitions to Fleming, Hart ; the Open Exhibition to C. H. O. Curtis, from the Royal School of Mines. The plans for the new University edifices at Strasburg have just been completed. They provide for over loo rooms to serve as auditoriums, museums, the inevitable German singing hall and fencing hall, &c., and will meet the needs of all sections of the university, with the exception of the medical faculty, which retains its old quarters, on account of the propinquity to the hospital. The attendance, which has fallen off during the past year, is now greater than ever before, the number of students for the present semester being 710. SCIENTIFIC SERIALS Journal de Physique, April. — In this number M. Vincent re- commends chloride of methyl as a frigorific agent, and indicates an abundant source of it. He employs a cylindrical copper vessel having double walls, between which the liquid is admitted through a peculiar cock from an adjoining vessel. In the central part is put an uncongealable liquid such as alcohol. The outer wall is enveloped in cork. On opening the cock the chloride of methyl enters into ebullition, and the temperature of the alcohol bath sinks to — 23°. By connecting with an air pump and making vacuum, a much lower temperature may be obtained. One pretty experiment with this apparatus is the crystallisation of mercury. — M. Gariel explains the new system of numbering glasses of spectacles, in which a unit called the dioptrie -is 'used, this being the power of a convergent lens of im. focal distance. The number of dioptrics for a particular lens is got by dividing im. by the focal distance reckoned in metres and decimal frac- tions of a metre, since the power varies in inverse ratio of the focal distance. Let Nd be the number of a lens reckoned in dioptrics and ^„ the focal distance in metres, then NdTj,^. = im., which gives one of the quantities when the other is known. — M. Pellat contributes a mathematical paper on the specific heats of vapours, and the phonograph occupies some attention, Meinorie della Societh degli Spettroscopisti Italiani, January, 1878. — Prof. Tacchini contributes a long paper on the appear- ance and constitution of the sun, based on the photographs of M. Jansen taken at Meudon ; there is also another by the same author, giving the observations of the positions in which the magnesium and 1474 lines appeared on the limb of the sun in June, 1877. The appendix contains a paper by L, Gruber on the falling stars of the first part of last November. February. — Notice of the death of Father Secchi, by the editor. — A paper by Prof. Rosetti on the temperature of the sun ; a description of the thermopile and the necessary acces- sories, together with the results, is given at length. — A table showing the number of spots and protuberances, and the heights of the latter during the first half of the year 1877, and drawings of the chromosphere for the months of November and Decem- ber made at Rome, by Prof. Tacchini. March. — A note and table by Prof. Tacchini showing the position on the sun's limb when the magnesium and 1474 lines were seen during June, 1877. Also a summary of the positions of the same during the first half 0/ the year 1877. SOCIETIES AND ACADEMIES London Royal Society. — " Note on the Specific Gravity of the Va- pours of the Chlorides of Thallium and Lead," by Henry E. Roscoe, F.R.S. , Professor of Chemistry in Owens College, Manchester. Experimental difficulties of so serious a nature surround the attempt to ascertain the specific gravity of vapours at a high temperature that, in spite of the interest which attaches to this subject, but few additions have been made in our knowledge in this direction since the researches of Deville and Troost. The present experiments, of which this notice contains the first results, have been made with the object of so simplifying the process as to render it easy to determine the specific gravity of the vapours of bodies possessing high boiling points with a degree of accuracy sufficient for the purpose of controlling their molecular weights. The method consists in vaporising the substance under ex- amination in long-necked glazed porcelain globes of known capacity placed in a muffle raised to bright redness. The tem- perature of the globe is ascertained by a calorimetric determina- tion made with heavy platinum weights placed in the muffle, this determination being checked by the simultaneous insertion in the muffle of a second globe containing mercury. The porcelain globes having a capacity of about 300 cub, centims., and containing from three to nine grams of substance, are closed by loosely-fitting stoppers of baked clay, and then gradually introduced in the muffle. After remaining there until no further escape of vapour is observed, and until the tempera- ture has become constant, the globes are quickly withdrawn from the muffle and their contents removed and analysed, the temperature being in each case ascertained by the calorimetric method at the time of withdrawal of the globe. The following determinations of the specific gravity of mercury vapour serve to show the reliability of the method : — Experiment I. 11. „ in. „ IV. V. Temperature determined calorimetrically. o ... ICI9 ... Specific gravity of mercury vapour. ... ... 6'92 894 675 815 6-91 972 577 1047 7-05 the calculated specific gravity (Hg= 198*8) being 6728, Before determining the specific gravity of the vapour of thallium chloride it was ascertained that this compound does not yune 20, 1878] NATURE 215 give off free chlorine when volatilised at a red-heat, and that the subliaiate contains thallium and chlorine in the atomic ratio of equality. In each experiment the total amount of thallium and of chlorine remaining in the globe was determined by analysis, and the specific gravity calculated from their sum. Experiment I. ... II. ... „ III. ... „ IV. ... V. ... „ VI „ VII. ... The specific gravity of thallium chloride vapour calculated upon the supposition that the molecular weight of the compound is 238'07, and its formula TlCl, is 8"49, Four determinations of the specific gravity of mercury vapour made simultaneously with four of the above experiments gave as a mean the number 6'0 instead of 6'728. The specific gravity of the vapour of lead chloride was made in a similar way, but the temperature required for complete volatilisation is much higher than that needed in the case of the last compound. The residue left in the globes was completely soluble in hot water, and contained lead and chlorine in the proportion of one atom of the former to 2"o8 of the latter. Temperature Specific gravity determined of the vapour of caloi-lmetr'.cally. thallium chloride ... 859 ... S-I5 ... 828 ... 8-28 ... IO15 ... 8'g6 ... 859 ... 7 "43 ... 1026 ... 8-75 ... 852 ... 8-6o ... 837 ... 7-84 Temperature determined calorimetrlcally. Specific gravity of the vapour of lead chloride. Experiment I. ... II. ... III. ... IV. ... ... 1046 9*12 ... 1089 972 ••• 1077 9-51 ... 1070 9'64 The specific gravity calculated from the formula PbCl2=277"i4 is 9-62. I hope before long to be able to lay before the Society the results of specific gravity determinations of the vapours of other compound and elementary bodies, togettier with the whole of the experimental details. Anthropological Institute, May 14. — Mr. John Evans, D.C.L,, F.R.S., president, in the chair. — Capt. Dillon ex- hibited a 'Series of flint implements, collected in the neighbour- hood of Ditchley, Oxfordshire, and a number of others, from the drift gravel of the sea valley near Clapton, were exhibited by Mr. Worthington G. Smith. The following papers were read by the author. Prof. Rolleston, M.P., F.R.S. — Description of a male skeleton found at Cissbury by Mr. J. Park Harrison. The paper was illustrated by a semidiagrammatic of the pit whence the skeleton had come ; the principal parts of the skeleton itself, some bones of ox, goat, pig, and red deer, and finally, a large quantity of worked flints and some lumps of iron pyrites were upon the table. Much help had been received as to the preserva- tion of the skeleton from Dr. Kelly, the Medical Officer of Health for the district. There was no doubt the skeleton had belonged to a man wath a markedly dolichocephalic skull, the length-breadth index being 71, but not tapeinocephalic, the length-height index being 76 ; his stature had been something under 5 feet, either as calculated from the long bones or by .simple measurement of the skeleton as laid out and increased by the addition of one inch for calcaneal and cranial integuments. The age had been something between 25 and 30, the absence of wear on the w-isdom teeth being deceptive owing to the non- development of one of these teeth and the small size of another. The owner of the skeleton had suffered from infantile cerebral hemiplegia, the right humeous being half an inch longer, and the right radms ^" longer than the corresponding bone on the left side, whilst the femur were equal in length, and the right tibia only '^y longer than the left. This pathological condition, how- ever, did not account for some very striking characters of the limb-bone<;, which were equally prominent on both sides of the body : these being the platyenemy of the tibiae, the anterior convexity, and from side to side flattening of the humeri, and the curved upward end of the illux. Altogether the osteologial peculiarities of the skeleton were as distinct evidences for its antiquity as its mode of burial. — On the excavation of three round barrows at Sigwell, near South Cadbury, in the parish of Compton, Somerset. These three round barrows belonged to the bronze age, no trace of iron, except such as had been accidently, and demonstrably so, introduced, being found in any of them. The interments in them had been in the way of cremation, and in one case the ashes had been gathered into a bark coffin and a bronze dagger placed with them. In one barrow no interment was found ; in another the ashes occupied an area of only an inch in diameter ; and in both cases the bones had been carefully picked out of the embers of the funeral pile and interred apart, though, in neither case, in an urn. Fragmentary pieces of coarse pottery, however, were found here and there throughout the mass of the barrows, and, though there were no flints to be found in the immediate neigh- bourhood, great abundance of chipped flints and some scrapers were found, and notably one very beautiful one by the Rev. J. A. Bennett, to whose association very much of the success of the exploration was due. Physical Society, May 11. — Prof. W.G.Adams, president, in the chair. — The following candidate was elected a Member of the Society : Rev. P. Magnus, B.A., B.Sc — Mr. J. Norman Lockyer, F.R.S., read a paper on some recent researches in solar chemistry, a report of which is deferred for the present. — Sir William Thomson, LL.D., F.R.S. , described and exhibited the apparatus he has employed in recent researches on the in- fluence of stress on magnetisation, a detailed account of which he has submitted to the Royal Society ; he also, in part, described them at the Royal Institution on May 10, but at- tention was not then directed to the experimental details now brought before the Society. The rod or wire under examination was surrounded by two co-axial wire helices, the outer of which was connected with the battery, and the inner with a ballistic galvanometer, that is, one that acts with regard to electric impulses just as Robins' ballistic pendulum. It was some years ago discovered by Villari that a longitudinal pull augments the temporarj- induced magnetism of soft iron bars or wires when the magnetising force is less than a certain critical value, and diminishes it when the magnetising force exceeds that value ; in either case the residual magnetism is augmented when the force is applied and diminished when it is removed. Sir W. Thomson has found the critical value for soft iron to be about twenty-four times the vertical component of the earth's magnetic force. It is therefore approximately 10 C.G.S. units. In the case of some bars of nickel and cobalt specially prepared for him by Mr. Wharton, of Philadelphia, he finds opposite effects. With the amounts of magnetising force used the effect of pull was to diminish magnetisation, but the amount of this effect \vas less ^^■ith the highest magnetising forces than with a certain degree of magnetising force which was found to make it a maximum with probably or possibly a critical value. But this value had not been reached by the magnetising force hitherto applied. The next branch of the inquiry had reference to the transverse stress obtained by water pressure within a gun-barrel, and it was ascertained to have opposite effects to those found by Villari in the case of longitudinal pull. The critical point in soft iron for transverse pull is at about 25 C.G.S. units. Sir W. Thomson has been examining the effect of torsion on a wire that is at the same time exposed to longitudinal pull, confining himself in his first set of experiments to magnetisation under the sole influence of the vertical component of terrestrial magnetism. His results showed, with every amount of longitu- dinal pull, a diminution of magnetisation produced by torsion in either direction, thus extending a conclusion arrived at by Mat- teucci, Wertheim, and Wiedemann, regarding the effect of torsion unaccompanied by longitudinal stress. But it now appears that this effect of torsion is very remarkably diminished by a large pulling force nearly reaching the limits of elasticity. In con- clusion. Sir W. Thomson called attention to a very different and extremely interesting effect of torsion discovered by Wiedemann — the development of longitudinal magnetisation in an iron wire by twisting it while a current of electricity is flowing along it. This effect, he pointed out, is just what would result from the seolotropic susceptibility for magnetisation due to the oeolotropic stress produced in the outer portion of the wire by the torsion, supposing the tangential magnetising force to be less than a certain critical value intermediate between the Villari critical value and the more than twofold greater critical value which Sir W. Thomson has found for transverse magnetising force.. But he pointed out that another cause was also positively or. nega- tively efficient in contributing to Wiedemann's result. This cause is the difference of electric conductivity in different directions 2r6 NATURE \_yune 20, 1878 which may be inferred from Sir W. Thomson's early experi- ments and from Mr. Tomlinson's recent confirmations and ex- tensions of the conclusions to which he wis led regarding the effect of stress on the electric conductivity of metals. It is much to be desired that Mr. Tomlinson should continue his experi- ments ; but in the meantime it seems probable that the electric conductivity in the outer parts of an iron wire twisted within its limits of torsional elasticity is maximum and minimum in the two spirals at 45° to its length, being minimum in that one of them which is of the same name as the twist, that is, the one in the direction of the maximum extension of the substance ; and the conductivity is a maximum in the other 45° spiral which is the direction of maximum contraction of the substance. The effect of this seolotropic conductivity, if it exists, must be to cause the electric currents to flow in spirals of opposite spirality to that of the twist and to produce a corresponding amount of longitudinal magnetisation. The effect of this is to develop, at the end by which the current enters, a true south pole when the twist is right-handed, and a true north pole when left-handed, which is opposite to Wiedemann's result. And if the tangential mag- netising force exceeds the critical value, the effect of the asolotropic magnetic susceptibility also is opposite to Wiede- mann's result. This is a subject of great interest, and requires further investigation. Photographic Society, May 14. — J. Glaishcr, F.R.S., pre- sident, in the chair. — Papers were read by Capt. Abney, K.E., F.R.S., on photography at the least refrangible end of the spectrum, and on some photographic phenomena, by W. England, on dry plate processes, and by T. S. Davis, F.C.S., on a tourist's preservative dry plate process. — Capt. Abney in his paper described the means by which he obtained a photo- graph of the spectrum beyond the B red line by using one of Rutherford's reflection gratings containing 17,280 lines to the inch, which gives a double spectrum outside a central white light, the resulting negative contained 130 perfectly defined lines, many never yet seen by the human eye, the wave length of the lowest lines being about 10,000 tenth metres. Rome R. Accademia dei Lincei, Mar. 3. — The following, among other papers, were read : — Geological and paljeon- tological studies on the middle cretaceous of Southern Italy, by M. Sequenza. — On the Italian expedition to Equatorial Africa, by M. Correnti. — On pensile shoots, with measurements of the vertical aiid horizontal angles, by M. Robert. — Prehistoric Cala- brian objects, by M. Ruggeri. — Graphic determination of the forces in reticular woodwork, by M. Favero. — Statistics of the mortality, diseases, and reforms of the Italian army from i860 to 1875, compared with those of other European armies, by M. Sormano. — On the nummulitic horizon near Castelnuovo deir Abate, in the province of Siena. Paris Academy of Sciences, June 10. — M. Fizeau in the chair. — The following among other papers were read : — On the cubes or prisms of M. Rohart for the destruction of phylloxera, by M. Chevreul. He finds they contain about thirty per cent, sulphide of carbon. Their efficacy surprises him. — On the large number of joints, mostly perpendicular to each other, which divide the meteoric iron of Santa Catharina (Brazil), by M. Daubree. In a weight of 23 kilos, were found 1,350 small fragments of iron, each about 17 grammes weight ; this would give 25,000 for the 500 kilos, which have come to Europe. — On the source of excito-sudorsal nerve-fibres of the anterior limbs of the cat, by M. Vulpian. They come principally from the spinal nerve, with the spinal roots of the upper thoracic ganglion ; but some come directly from the cord by the roots of the nerves forming the brachial plexus, — Experiments proving that the nerve-fibres, whose excitation causes dilatation of the pupil, do not all proceed from the cervical cord of the great sympa- thetic, by M. Vulpian. Some come directly from the ence- phalon, mixed probably with fibres of cranial nerves, whose branches enter into connection with the ophthalmic ganglion. — M. Lecoq de Boisbaudran was elected Correspondent for the Section of Chemistry, in room of the late M. Malaguti.— On the geographical distribution of Mexican Graminese, by M. Fournier. He has brought the number up to 638. He divides them into two groups^ the one special to Mexico, or partly common to the Andine and northern regions, distinguished by slenderness of leaves and panicles ; and the other expanded in the tropical region and noted for larger size. The former inhabit, by preference, mountainous and dry parts ; the latter the banks of rivers and moist parts. — On the artificial produc- tion of natron or natural carbonate of soda, by the action of carbonate of magnesia on chloride of sodium, by M. Cloez. This is done at ordinary temperature. The author thinks the phenomenon may occur in nature, explaining at once the production of natron and the large quantity of chloride of magnesium found in solution in the water of salt lakes. — Oi» modifications produced in the animal system by vai'ious albumi- noid substances injected into the vessels, by MM. Bechamp and Baltus. They experimented on dogs both with solutions of natural albumen and with pure albumens of known rotatory power. The latter were not, or were only partly, eliminated. — Influence of the physical state of gallium on its electro-chemical role, by M. Reg- nault. He made a small couple (about 489 mm.) of which the two metallic elements were solid and liquid gallium, and were connected by a layer of neutral sulphate of gallium dissolved in water. This caused, in a fine wire galvanometer, constant de- flections of more than 40°, in a direction showing that the sheet of liquid had negative tension, while the solid plate had positive. This proves the influence of heat of constitution of a simple me- tallic body on the energy of its chemical properties. — On starch, by MM, Musculus and Gruber, They give a list of substances produced at expense of starch under the influence of diastase or diluted and boiling sulphuric acid, — Action of fluoride of boron on certain classes of organic compounds, by M, Landolph. Fluoride of boron combines indefinite proportions, equivalent for equivalent, with aldehydes, with acetones, and with carbonyles. — Researches on the peptones, by M, Henninger. These re» searches seem to indicate that the peptones result from a fixation of water on albuminoid matters, and they thus confirm a hypo- thesis enunciated by M. Dumas more than thirty years ago that pepsine causes the liquefaction of azotised matters by a pheno- menon similar to that of diastase on starch. — Anatomical observa- tions on certain cutaneous excretory glands in the fluviatile tortoises of China, by M, Rathonis. These glands are distinct from those formerly described by Owen and others ; their physiological r6le\% unknown. — Presence and rdle of ammoniacal salts in modern seas, and in the saliferous strata of all ages, by M. Dieulafait. All mineral waters, whether sulphurous or not, whether thermal or not, must contain anomalous quantities of ammoniacal salts. — Experimental proof of the incomplete crossing of the nerve-fibres in the chiasma of the optic nerves ; longi tudinal and median section of the chiasma not followed by blindness, by M, Nicati. CONTENTS Pagb Tertiary Flora OF North America. By J, S. Gardner F.G.S . 389 Fouribr's "Analytical Theory OF Heat " jgz Our Book Shelf: — Topinard's "Anthropology" . . 192 Smith's " Tailed Amphibians, Including the Caecilians " . -193 Letters to the Editor :— Indian Rainfall. — S. A. Hill 1Q3 A Twenty Years' Error in the Geography of AustraLa. — Alfred R. Wallace 193 Opening of Museums on Sundays. — Prof, W. T. Thiselton Dyer 194 Socialism in South Africa. — F. E. Colinso 194 The Telephone Relay or Repeater.— Prjfessors Edwin J. Hous- ton; Elihu Thomson . 194 New Form of Microphone Receiving-Instrument. — W. J. Millar. 194 A Waterspout. — E. Wethered 194 Fortunate " Escape." — Electrified 195 Velocity of Light. — Albert A. Michelson {With lUiisiratwns) . 195 University College. — Talfourd Ely, Secretary 195 Examination of Small Organisms in Water. — Dr. R. E. Dudgeon 196 The Late Mr. Hewitson 1^6 Andreas von Ettingshausen 197 A New Crater on the Lunar Surface 197 Deep-Sea Dredging off the Gulf of Mexico. By Prof. E. Perceval Wright 198 Meteorological Notes 198 Our Astronomical Column : — The Total Solar Eclipses of May 16, 1882, and August 18, 1887 . 199 Geographical Notes 200 The Great Frozen Sea {IVitk lUustratioti) 201 On the Structure and Develop.me.nt of the Snake, By Prof. W. K. Parker, F.R.S. (friVA///?> >> - 0*96 - i-i8 - 2"2I II II II - 0-I3 - I -61 12 II Honolulu >> >» - I '29 - 17s -071 II II 10 - 0"2I - 0-54 12 12 Rodriguez >> i> >> >> + I*i9 + 0-23 -I-2-IO + 0-I4 + 1-46 II ID 10 II II + 2-44 + 2'49 + 274 + 1*27 + 2-31 9 6 8 10 9 Burnham, N.Z. ... + 0-68 13 i \ + 1-89 3 10 Kerguelen ■+I-5I 8 1 0 The above is perhaps the best way to exhibit the nature of the discordances. They might also have been shown as apparent errors of the tabular distance of centres. The discordances of any one station are too large to admit of the measures being employed with advantage for the determination of the solar parallax. They are due to inherent defects of the photographic images. The -reason why at the two northern stations the signs are all minus, while at the three southern they are a.\\ plus, is at present obscure, and I am not prepared to offer any suggestion as to the cause. THE NORWEGIAN NORTH ATLANTIC EXPEDITION T SEND you inclosed a clip from the Dagbladeii ■*■ containing the route of our expedition for the ■coming summer, I hope to be able to send you notes from our expedition during our sereral stays in Hammerfest. H. Mohn "According to the plan of this expedition, the Voeringen was to start from Bergen on its third and last cruise on the 15th inst. It will probably have reached Tromsoe by the 19th inst., and, after taking on board a pilot acquainted with the northern waters, have immediately proceeded to Alten Fiord, mainly to inspect the meteorological station there, and to examine the animal and plant-life of the Fiord bottom. The magnetic observations required for regulating the compasses, &c., were to be made at Hammerfest between the 21st and 24th inst. The course was then to be set eastwards, in order to examine the relations of depth and animal life, &c., in two of the fiords of Finmark. After touching at Vardoe on the 27th, the voyage is to be continued to a point midway between Vardoe and Novaya Zemlya, in order to take soundings and determine the boundary of the ice-cold water in the East Polar Sea, which hitherto in these regions has only been observed at Bear Island by the well-known Austrian Polar explorer Weyprecht, in his excursion thither several years ago in the Tromsoe yacht Sa7nson. This thorough examination of the sea off the north-east coast of Norway, towards Novaya Zemlya will be of special importance for the study of the migrations of the "lodde" {Maloius arcticus), as it is probable that it is there that this salmon-like fish has its abode whence in spring it makes its way in large shoals to the coast of Finmark to spawn, pursued by the cod, which follows it and is accordingly taken ; while the so-called " lodde " fish, as is well known, is not fished for, because it is not suitable for human food, on account of its penetrating unpleasant odour. This eastward cruise of the Voeringen will scarcely occupy more than ten days, as the sea is here so shallow that taking soundings, &c., need not occupy much time, and the Voerins^en may accordingly be expected back at Hammerfest on July 7, to take on board coal, water, &c., for a new cruise to the westward in the navigable waters north of Jan Mayen, which the expedition visited last year ; thence to the Greenland ice, where the seal fishing is usually carried on, in order to ascertain the boundary between the Greenland Polar current and the Gulf Stream. The stretch of sea that will be traversed by the Voeringeti has not hitherto been surveyed, and here will doubtless be found, by means of the lead, the begin- ning of the great Polar sea-depth which runs in between Greenland and Spitzbergen. The Voeringen will then return to Hammerfest to make preparations for the third cruise. This cruise, which will be the last, will be commenced on July 29, and be occupied with the survey of the navi- gable waters between Bear Island and Spitzbergen, where the well-known shark fishing is prosecuted, and the great sea-deeps off the west coast of Spitzbergen (76" to 80° N. lat.) which hitherto have only been surveyed, and that incompletely, by two of the Swedish expeditions. The Voeringen will go as far north as it can for ice, but there is certainly no great expectation that the Norwegian expedition will be successful in carrying off the prize in the competition with other nations to reach the North Pole, for the Voeringen will certainly soon meet with ice in the navigable waters on the north coast of Spitzbergen, and it is not fitted out for a North Pole expedition. Leaving it to the enterprising publisher of the New York Herald and others to endeavour to reach this goal, the Voeringen will, instead, after having turned southwards, survey the fiords and banks on the west coast of Spitzbergen. There the Nor- wegian fishermen, as is well known, carry on a not incon- siderable cod-fishing, the yearly catch numbering 300,000 to 400,000 fish. But if we keep in view the recent disco- very of the great fishing bank off the Lofoten Islands, it will be seen that the fishermen need not undei-take the long and troublesome voyage to Spitzbergen to catch cod. They will find superabundence of larger and better fish at the banks oft" Vesteraalen, so to speak, lying before their own door. But these Lofoten fishing banks are for the time being visited by the Norwegian fishermen as little as the bank abounding in fish which lies off the Froey Islands (north-west of the mouth of Trondhjem Fiord), although the latter was known to old fishermen. The surveying-steamer Hansfeen has now mapped it. It is besides beyond all doubt that one of the practical results of the Norwegian North Atlantic Expeditions will be a better turning to account of the rich fishing banks of whose position, animal and plant life, more precise information has now been obtained. The return from Spitzbergen will take place at the end of August, and the Voeringen, after having touched at Hammerfest or Tromsoe, and Bergen, where the mem- bers of the expedition resident there witl land will June 27, 1878] NATURE 223 probably resume its course in the middle of September, terminate its voyage in the harbour of Horten." The members of the expedition are the same this year as last, viz., Profs. Dr. H. Mohn, meteorologist ; Dr. G. D. Sars, Dr. Danielssen, and Herr H. Friele, zoologists; candidate Torncee, chemist; assistant-candi- date Schmelck, physicist and chemist ; and the landscape- painter Herr Schiertz, as artist. The Voeringen will be commanded this year, as formerly, by Capt. Wille of the Royal (Norwegian) Navy, the second in command being the sailing-master, Capt. Greig. The expedition carries "with it several valuable new instruments for measuring more exactly the temperature of the water at great depths ; some of them have, with great good will, been obtained from the members of the English Challenger expedition. As in the preceding years. Prof. H. Mohn will send to Nature communications from the expe- dition. PHYSICAL SCIENCE FOR ARTISTS^ VI. •T^HE diagrams given in my last article should have -■■ made it quite clear that the various sunset and sun- rise colours are due to the absorption produced by dif- ferent thicknesses of aqueous vapour ; that the colours of clouds are due to light falling upon them after ab- sorption by different thicknesses of aqueous vapour ; and finally that the blue colour of the sky in the zenith is due to the fact that the pure gases in our atmosphere exist in that molecular grouping which vibrates in har- mony with the short waves of light. The blue sky, however, is scarcely ever a true blue. Between us and it there is ever a misty veil which re- flects to us the white light of the sun, as an examination of it'by a pocket spectroscope will prove to anybody. It is to the variation in the quantity of this misty veil that the difference in the colour in the sky at great and low elevations, in different climates, and in the same climate, when clouds are about to form and when scarcely the germs of clouds are present, is to be ascribed. The thickness of our atmosphere is so moderate that neither the hypothetical red nor the blue molecules of aqueous vapour are competent, except during thunderstorms, to influence its colour as they undoubtedly do near the horizon. A glance at Fig. 4 in the last article will explain how it is that sometimes in the case of clouds we find the before- stated order of sunset colours reversed. If, for instance, we imagine a cloud lying along the curve xs', an observer attf willsee a cloud at xhigher above the horizon than one at /, but the cloud at x will have received light through a greater thickness of atmosphere than the cloud at s". The red, therefore, at x will be more fonce. than at s' j the order of colour, though not of brilliancy, will be reversed. So far we have considered these colours looking towards the rising or setting sun. Let us now turn our back on that luminary. It will be at once obvious that if, for instance, we take a point on the horizon, there will be an enormous increase in the thickness of atmosphere traversed by the ray ; indeed, we may say that for this point the absorption will be threefold. Hence a consider- able reduction of light, a ruddier tinge, due to the in- creased absorption of the more complex molecules, and a mingling of the ruddier light with the blue sky. In the voyage which I made to India in 1871 I scarcely ever missed a sunrise or a sunset, and although the point of sunrise or sunset was almost always the scene of a succession of glories unsurpassed in beauty, the point opposite was, if possible, more interesting, the colours were more subdued, and of a more composite order, but ' Continued frcm p. 157. the work of law went on there, as elsewhere. If any clouds happened to be overhead, their greatest glory, which, as I have already shown, can only be put on when the sun is below the horizon — and the sun rises or sinks much more rapidly there than with us — was the herald of the shadow of the earth on the illuminated sky, which crept on a gigantic, mysterious crescent. That the shadow of the earth could thus be seen was new to me, and I am the more glad, therefore, seeing that many may doubt it still, to substantiate my observation and its explanation by a quotation from Prof. Briicke, one of the most distin- guished members of the Vienna University. Prof. Briicke has been doing on the Continent what I have been at- tempting to do in these articles, and just before my last one appeared I saw in La Revue Scientifique an extract from his forthcoming work " Principes Scientifiques des Beaux Arts." I am delighted to see how much at one we are, but for the moment I shall content myself by giving what he says on the point to which I have referred. Talking of sunset he writes : — "We see on the horizon to the east a grey blue stratum rising higher and higher, and stopping at that portion of the sky coloured red : it is the shadow of the earth. " The shadow of the earth must always encounter aa unilluminated part of the atmosphere. As this shadow- does not fall on a surface, but on a great number of particles spread abroad in space, it is material, that is to say, it has three dimensions, and we see it, foreshortened — in perspective. " Sometimes the regions above it are divided in a radial direction into sectors, some of which are dark, like the shadow of the earth, others red. These resemble in the sky the rays of the aurora borealis, and often change their place and size ; in French they are termed 'les rayons de cr^puscule.' They are due to the fact that in the path of the solar rays there are masses of clouds which only give passage to isolated ones here and there, which make their presence felt by the luminous train which they leave among the particles of the atmosphere. Hence arise those red prismatic masses spread abroad in the air east and west. At the zenith we do not remark them, because the vision cuts across them, and the stratum of illuminated particles is not thick enough to render them sensible ; but we see them painted on the eastern sky because we regard them obliquely in the sense of their length ; we see them in perspective. By their nature and their mode of origin they do not differ from the beams which the setting sun throws between the intervals in the clouds, nor from those which it sometimes casts in the morning or after- noon through the clouds, when the peasants say that * the sun is drawing water.' ' Voilk un bouillon qui chauffe.' " This paragraph not only supports my view, but it opens up several very interesting points on which, if space permitted, there would be much to say ; one or two words, however, must suffice. The rifts to which Prof. Briicke has drawn attention do not always arise from clouds ; in fact, they are not seen in their greatest vividness when they do. One evening I saw them thrown, in a perfectly cloudless sky (in fact, there had been no cloud all day), by the sky-line of Socotra, which island we had passed during the day, and which was below the horizon at the time. Capt. Parish, in command of the Mirzapore, to whom I appealed at the time, took the bearing of these rifts, which, in their sharpness and magnitude, were almost appalling, and put the question beyond all doubt. "With regard to the "sun drawing water," artists should note the absence of all colour and the radial direction of the beams, all meeting in the sun's place. For some reason or other many artists are not yet quite clear about this appearance, and compromise matters by making the beams look like a distant rain-shower. There are some notable examples of this in the South 124 NATURE yjune 27, 1878 Kensington Museum. That phenomena so diverse in their origin and appearance should be mistaken for each other does not say too much in favour of the cultivation of the observational faculties of artists as a rule, I shall next refer to two or three other questions which have been dealt with by Prof. Briicke in the article to which I have referred. Prof. Briicke is again with me to a certain extent in tracing the origin of most sky- colour to a defect of the blue light, but he does not make the attempt to run it to earth that I have done, by ascribing it to aqueous vapour ; indeed he considers it rather due, I take it, to the presence of solid particles in the air. Thus, after pointing out that the dawn is generally orange, and the sunset redder, he states that at night the • quantity of molecules capable of troubling the air is gene- rally greater. For my own part, I should be inclined to ask whether, during the night, the molecules of aqueous vapour which absorb the blue have not been driven into higher forms — deiv being one of them — owing to the reduction of temperature. Tiiis would at once explain not only the generic difference between sunrise and sunset colours, which is more marked here than in the tropics, but also the golden instead of red sunsets which accompany the formation of cloud. Another point of difference. Prof. Briicke considers green sky as an effect of contrast produced by the quan- tity of red light which enters the eye. I cannot agree to this, first, because I have given a physical reason for the green ; and secondly, because I have observed it without any strong contrast of colour to mislead the eye. The considerable darkening of the green after- sunset is, I believe, purely physiological ; and it is ah effect of so curious a nature, that it raises several inte- resting questions with regard to the manner in which the eye grapples with the middle colours of the spectrum, namely, the orange, yellow, and green, which can be made to change to a certain extent according as the light is more or less intense, which does not happen with the other colours. The changes in mountain scenery form the subject of several interesting remarks by Prof. Briicke. As long as distant mountains are illuminated by a high sun, their outlines are not very clear ; because, as he well puts it, the reflection of this light from the lower strata of the atmosphere is then so great that the illumination at the horizon, where mountains are, is as strong as where they are not. He then points out that at night the setting sun fills the sky towards the west with a great brightness which renders the profiles of the mountains between us and the sun much darker. Their contours are neatly detached, but it is not only on the horizon that this is seen ; the various chains are better distinguished, and appear one behind the other like the scenes in a theatre, because the light in which we see them does not come from them but from the interposed air. The sides of the mountains which we see are dark because the other sides are turned towards the sun, but the various thicknesses of air interposed between us and them reflect to us the sunlight ; hence the atmo- sphere of a picture is truly the work of the air. Here is what Prof. Briicke says about sunset tints ; I do not follow him in all his explanations : — ''When the sun reaches the horizon and the red tint is developed, the colours of the landscape change in their turn and the moun- tains themselves appear red when we regard no longer their shadows but the illuminated air which lies in front of them." It appears to me this gives too much work to the air ; a rock surface is generally as capable of dispersing red light which falls upon it, as a molecule of aqueous vapour is ; '' still the tint has not the intensity of the alpine colour ; it is a red less intense and more empurpled, which sometimes approaches even the violet or the lilac." I shall have a word to say on this, but I will first give Prof. Briicke' s explanation : — " Two causes are at work in this latter case ; the first is the mixture of red and blue light. At night when the sky is clear the shadows are coloured a strong blue. The shadow region is illuminated by the blue light of the sky, and appears more pronounced, owing to the contrast of the red- dish-yellow light, as we have already seen. The illu- minated air reflects the blue rays more abundantly than the red ones, and consequently the former have the ascend- ency. If not scientifically correct, it is at least practically so, to suppose the blue light in which we see the moun- tains bathed after sunset to be mixed with purple or lilac. The second cause of the violet tone in the distances to the west is to be found in the frequent contrast. In the west, in fact, a great part of the sky is illuminated by yellow light; often this yellow is a perfect sulphur- colour, which contrast makes objects even in the middle distance, which turn their dark sides to us, appear violet ; thus, looking to the west, dark, unploughed earth appears violet when the majority of terrestrial objects turn their dark sides towards us." An observation I made at Cannes last year leads me to think that the whole cause of this purple colour has not been stated in the foregoing. It was near the hour of sunset, and I was looking towards the south- west, delighting in the blue colour at the foot of Les Estrelles — while their crests were being gilded by the sunset — when, almost instantaneously, the valley to the north of these hills was enfiladed by a beam from the sun itself, which threw part of the aqueous vapour in the valley into a frenzy of gold. This gra- dually got ruddier as the sun got lower, and the amount of vapour lighted up between me and the blue vapour at the foot of the hills was at the same time reduced; the blue and the red then melted together into the richest and most beautiful purple that I, at all events, have ever seen. We have only, then, to assume that, when we thus see purple, that colour is produced by a mixture of particles, some of which are reflecting to us the blue light of the sky, because they can do no other, while others, again, are reflecting to us the red light of sunset, because it is more powerful than the light from the sky. J. Norman Lockyer AN ECLIPSE SPECTROSCOPE SOME little time ago I communicated to the Royal Society a suggestion for the use of Mr. Ruther- furd's reflection gratings in obtaining photographs of the coming eclipse. The plan suggested was that the grating should be placed short of the focal point of a telescope, and at right angles to its axis, and that the diffracted images of the chromosphere should be received on photographic plates adjusted for the different orders of spectra on either side the axis. I am glad to learn from Prof. Newcomb that the value of this method of obser- vation will probably be tested by Prof. Young, who is in charge of one of the six expeditions already organised to observe the eclipse. The chief defect in this mode of observation lies in the difficulty of determining the posi- tion of the lines photographed, supposing the chromo- spheric spectrum to vary considerably from the ordinary solar one so far as the intensity of the lines is con- cerned ; and as it seemed desirable that these gratings should be utilised for less serious attacks, I have recently been endeavouring to see if the method can be improved. The annexed woodcut shows one form of the new arrangement, which has many conveniences. It is a rough model on wood, but will suffice to show the method of use. The grating, which is free to rotate, is placed in front of a little telescope of low magnifying power and the stand which carries both is so placed and the grating so JufU 27, 1878] NATURE 225 adjusted that the image of the light source is seen in the little telescope reflected by the general surface of the metal grating. Supposing a circle and micrometer at- tached, represented by the Avooden bar at the top, the reading would now be zero. Next, and this is the new point, a piece of glass silvered on the front surface is fixed with its surface parallel to the surface of the grating, the side of which it covers. When this is in perfect adjustment the images produced by the movable grating and the fixed mirror are super- posed. Let us suppose the light source to be a Geissler tube, we get a single image of it ; the fixed mirror is then very slightly inclined, so that its image lies a little above or below the one due to the grating. We now by the movable arm at top rotate the grating, the grating image vanishes from the field of view, and in a little time, if the rotation is continued, the blue of the first order spectrum makes its appearance. Each coloured image in the spec- trum can in turn be brought to coincidence, with the non- dispersed image of the tube thrown by the fixed mirfor, and readings of considerable accuracy can thus be obtained. The illumination of the image due to the fixed mirror can be easily regulated by changing its position with regard to the axis of the telescope pro- longed ; in no case of course should any part of the ruled surface of the grating be covered. With a ring slit illu- minated by the vapours of different metals, the pheno- mena observed are very interesting and novel ; with the fixed mirror slightly inclined, the image from the fixed mirror always in the centre of the field of view forms a capital point of comparison. More light is gained by employing an object-glass of short focus and placing the grating and fixed mirror at such a distance inside the foeus that the beam falls on the ruled surface and a small fraction of the fixed mirror. I hope the suggestion does not come too late to enable it to be utilised by the outposts during the coming eclipse. If it helps in enabling us to determine the position of the chromospheric line near H, the time I have spent on the little model will not have been thrown away. I may add that I have found that a prism of 60° dense flint placed in front of the lens of an ordinary photographic camera will give us, if properly focussed, a most useful spectrum of the eclipsed sun. J. Norman Lockyer OUR ASTRONOMICAL COLUMN Nearest Approximations of Small Planets to THE Earth's Orbit.— Out of the 187 minor planets now known there are ten which approach the earth's orbit at their perihelia within 0*9 of her mean distance from the sun, and which may therefore afford the mQSt advantageous opportunities for determination of the solar parallax by one or other method of observation of these bodies, already successfully applied : Medusa is omitted on account of uncertainty of elements. The nearest approach, 0798, is made by Clio, discovered by Luther in August, 1865. ^ihra, detected by Watson in June, 1873, makes the nearest approach to the sun r6i4 ; but the great depression of the planet below the plane of the ecliptic, at perihelion, prevents so near an approxi- mation to the earth's orbit as in the case of Clio. The following is a tabular view of the distances in the ten cases referred to : — Perihelioa Distance. 84. Clio ... 1-805 132. ^thra I'6l4 18. Melpomene... ... 1796 4^- Ariadne ... 1-834 12. Victoria ... 1-823 80. Sappho ... 1-835 8. Flora ... 1-856 33. Polyhymnia 1-890 42. Isis 1-890 50. Virginia ... 1-896 Hellocento? . . Distance Latitude from in Perihelion. Earth's Orbit. + i°57 ... 0-798 ,. - 23 45. - 0-813 - 7 9 ... 0-815 + o 48 ... 0-818 + 7 40 ... 0^828 + 5 53 ••• 0-842 - 5 45 .•• 0-874 - o 53 ... 0-882 - 6 53 ... 0-892 - o 47 ... 0-896 If we extended our limit to 1-0 we should include, in addition to the above, Felicitas, Phocea, Euterpe, Thyra, Echo, and Feronia. . While referring to the small planets it may be remarked that, between the perihelion of jEthra and the aphelion of Hilda, there is a difference of 2-98 ; and between the aphelion of Flora and the perihelion of Hilda 076, or upwards of three-fourths of the radius of the earth's orbit. The periods of Flora and Hilda being respec- tively 3-27 and 7-85 years exhibit a difference of 4-58 years. These are the extremes, as they result from the latest and most complete catalogue of elements. According to the last Circular of the Berliner Jahrbuch, the following names have been proposed : — For No. 177, Irma, for 180, Garumna, and for 186, Celuta. Measures of Double Stars. — Many applications for copies of the earlier volumes of " the Leyton Observa- tions " having been received after the edition had beeh exhausted, Mr. J. Gurney Barclay has issued a fourth volume containing the double star epochs from the com- mencement of observations at Leyton, with the addition of results to the end of 1877. This part includes also occultations and phenomena of Jupiter's satellites since 1865. The notes on the double-star observations coni- prise the principal epochs of other observers. The smaB companion of Procyon at a distance of about forty-five seconds, to which attention was first pointedly directed by Mr. Barclay in January, 1856, had the following posi- tion for 1 863 23, angle, 294° '88, distance 45'''-9, which, corrected for the proper motion of Procyon in the ihte'rval, gives for 1879-0 angle, 3i9°"3, distance 47''-3. The Astrono7nische Nachrichten, Nos. 2196-99, contain measures of double-stars made by Dr. Doberck at the observatory of Col. Cooper, Markree Castle, Sligo, from the end of 1875 to the spring of 1878. The list includes most of the well-known binary systems, y Coronae was single in the Markree instrument in 1876-77. ,. ' Mr. Ormond Stone, Director of the Observatory at Cincinnati, writes with respect to a remark in a notice of the Cincinnati measures of double-stars, which appeared in this column, and which might be misunderstood as implying that the work carried on at the American Obser- vatory is to a certain extent a duplication of that com- menced some time since with the refractor at Melbourne. Mr. EUery, however, has lately informed Mr. Ormond Stone that lais observations are limited to stars south of 35". The Binary Star a Centauri. — Mr. Maxwell Hall writes from Jamaica, on May 21, with reference to a Centauri : " Since my communication last year respecting this binary, the angle of position of the smaller star has rapidly increased at the rate of 60"" per annum. I have lately taken measures in the same manner as before, few in number, but with the greatest care, so that their con- cordance gives them great weight." Epoch 1878-38 Position 139°- 1 Distance 2" '4 Mr. Hall adds: "There can be no doubt that the smaller star is variable : according to my estimates it has diminished during the last year ; and I would therefore call attention to the subject " — and appends various esti- mates from \\ (Powell, Jacob) to 4 (Dunlop), also a table of the measured angles and distances to 1878, which it is 226 NATURE {June 27, 1878 unnecessary to give here, as they will be accessible to most readers who interest themselves on the subject of binary stars. For the interval 1864-76, in which Mr. Hall states he had not measures in his possession, the following may be cited : — Powell 1870* 10 Position 20-45 Distance 10-24 Russell 18707s „ 22-3 10-46 — 1872-47 M 25-5 9*74 EUery 1874-15 „ 30-5 8-00 Russell 1874-47 30"o 7-97 On the question of the brightness of the components Sir John Herschel says : — " Individually their magnitudes have been very differently estimated by other observers from what I consider to be their coirect values. All agree in assigning the first magnitude to the principal star, or that which follows in R.A. (1834-37) ; but whereas Lacaille, and after him Fallows, Johnson, Taylor, and Messrs. Dunlop and Rumker estimate the preceding star of the fourth magnitude, I have"never estimated its magnitude as seen with the equatorial lower than 2-3, and the mean of all the magnitudes assigned to it with this instrument is 1-73, or if by a mean of eleven obser- vations On the whole evidence afforded by my experience I am disposed to assign to it a magnitude which may be deemed indifferently either a very low first or a very high second." Sir John Herschel further con- sidered that "it is not necessary to recur to the hypo- thesis of variabiUty to account for this difference of esti- mation," and gave his reasons for this opinion (" Cape Observations," p. 300). BIOLOGICAL NOTES Decorative Colouring in Freshwater Fleas. — There is something essentially comic in the notion of a freshwater flea— a species of the entomostracous crus- taceous Daphnoidae— becoming beautifully ornamented with patches of scarlet and blue, for the purpose of seducing the affections of the opposite sex. If a scarlet coat is appreciated by the females of the very fleas of this great family to which we all belong, we ought not to be surprised at hereditary predispositions in favour of this colour, and should conclude on this ground, as on many others, that the civilian male Anthropini of western Europe have taken a foolish and unnatural step, within the last hundred years, in abandoning the use of brilliantly- coloured clothing, and giving over the exceptional advan- tages which it confers to soldiers and huntsmen. The figures given by Prof. August Weismann, in the Zeitschr. wiss. Zoologie (1878, Supplement i), show us the water- fleas, Polyphemus and Latona, most gorgeously got up an blue and scarlet. Goethe, though he never saw them, foretold their appearance : — ** Es war enimal ein Konig, der hatt' einen gros£en Floh, Den liebt' er gar nicht wenig, als wie seinen eignen Sohn, *»»♦*» In Sammet und in Seide, war er nun angethan, Hatte Bander auf den Kleide, hatt' auch ein Kreuz daran," &c., &c. It is to the elaborate and ingenious studies of Prof. Weismann on caterpillars — worthy to be placed by the side of the most original of Mr. Darwin's own inves- tigations— that we owe our knowledge of an exceedingly important cause of animal coloration, namely, that which is explained by the term "startling" or "terrifying" colouration (Schreckfarben). Just as in various human races the amorous of both sexes paint their faces and adorn their bodies in order to attract one another, so nature paints by sexual selection, and just as we dress our- selves up in wigs and gowns and spectacles, or tattoo our countenances in order to terrify evil-doers so (Prof. Weis- mann shows) does nature paint masks with staring eyes upon the feeble caterpillar's back in order that he may enjoy the privileges so usually gained by the ass in the lion' s skin. Brilliant patches of colour occur only in a few Daphnoidae (also in a few Phyllopoda), and after a very detailed investigation as to the variations which these patches of colour present in the different species, in the two sexes, and at different seasons and at different periods of growth, Prof. Weismann comes to the conclu- sion that they must be regarded as a decoration acquired by sexual selection which probably was first of all con- fined to the male sex, but subsequently, in most cases, became transmitted also to the other sex. Probably a reciprocal and alternating sexual selection favoured this transference to the female sex, the most brilliant females being chosen by the few males existing at the commence- ment of a sexual period, and the most brilliant males being chosen by the relatively few females existing at the end of such a period. The existence of these ** sexual periods" is a well established feature in the life-history of Ento- mostraca, alternating with parthenogenetic periods. From the fact that neighbouring colonies of the same species have a constantly differing arrangement of colour, it appears probable that the development of these deco- rative colour-patches took place after the isolation of the colonies, that is to say subsequently to the glacial period in northern Europe. The transference of the decorative coloration originally developed only by the males, took place in three directions— firstly to the other sex; secondly to the not-yet sexually mature period of growth ; and thirdly to the parthenogenetically produced gene- rations. In the various species of Daphnoidae with decorative coloration we find different degrees of com- pleteness of the transference in these three different directions. Only one species, viz., Latona, presents the highest degree or complete transference of the coloration to both sexes, all stages of growth and all generations of the -annual cycle. Prof. Weismann concludes that the Daphnoidae afford a further case in favour of the hypo- thesis that secondary sexual characters can be converted into general characteristics of the species, and that they confirm Mr. Darwin's theory of the origin of the colour- patterns of butterflies' wings. How Lepidoptera escape from their Cocoons.— The mode in which butterflies and moths free them- selves from their chrysalides has been a subject of some controversy, but of very little recent observation. With regard to the silkworm moth, Malpighi asserted that the animal first wets the silk with a liquid calculated to dissolve the gum that connects the threads, and then employs its lengthened head to push them aside and make an opening. Reaumur, however, maintained that the threads of silk are not merely pushed aside, but are actually severed, and believed that the eyes, which are the only hard organs of the head, are the instruments by which the threads are divided, their numerous minute facets serving the purpose of a fine file. That the threads are actually cut is the general view ; and the account of the breeding of silkworms, published in the American Philo- sophical Transactions, states that cocoons, out of which the moth has escaped, cannot be wound. On the other hand it is known to be a common practice with many moths the chrysalis of which is very hard, to discharge, immediately before issuing forth, a copious fluid from the mouth by which the shell is so softened that they are able to force their way through it. In an article in the American Natnralist for June, Dr. A. S. Packard, after reviewing our previous knowledge of the subject, gives an account of some interesting observations of his own. His attention being arrested by a rustling, cutting, and tearing sound, issuing from a cocoon of the large green swallow-tail silkworm moth, Actias luna, he discovered;, on examination, a sharp black point moving to and fro, and then another, until both points had cut a rough irregular slit, through Avhich the shoulders pf the moth could be seen vigorously moving from side to side. The hole or slit was made in one or two minutes, and the Juilt 2J, 1878] NATURE 227 moth worked its way at once out of the'slit. The wings at this time being very small and flabby, and the shoulders being alternately much raised, the points stuck up far enough to cut or saw through the cocoon. The wings were at first of a deep buff yellow, but in half an hour after they began to expand and to turn green. The black points can be detected when the wings are fully expanded, not being entirely covered by the hairs at the base of the wing. In this case no fluid was seen to exude from the mouth, and the cocoon was perfectly dry. The black points are seen, when magnified, to hare the form of a rude saw, and Dr. Packard -proposes for them the term sectores coconis. The cocoon-cutters were found in every other species of the sub-family y?//a« that was .examined ; in Telea polyphemtis they are large and well-developed ; they are rather small in Callosamia protttethea, Platysamia cecropid, P. Gloverii, Sainia cynthia, an Attacus from Nicaragua, and Attacus amazonia, Pack,, from Pebas, Peru ; large and well-marked in the European Saturnia pavonia-minor and Etidromis versicolora. In Bombyx mori the spines are not well-marked, and they are quite different from those of the Attaci. They are three sharp points, being acute angles of the pieces at the base of the wing. No such spines are present in Eacles imperialis. In the accompanying cut a represents a front view of a specimen of Actias lima which came out of the cocoon and died with the wings not expanded ; the shoulders are elevated, and the rudimentary wings hanging down ; ,/« J- the scatum, s the cocoon-cutter,^ the patagium. B represents another specimen with fully-developed wings ; m s the scatum, s t the scabellum of the meso-thoracic segment, s the cocoon-cutter, which is evidently a modi- fication of one of the pieces at the base of the fore-wings ; it is surrounded by membrane, allowing free movement. C and D are modifications of the spine or sector coconis considerably magnified, showing the five or six irregular teeth on the cutting edge, the spine being sharp, curved, and conical. It will be seen that it acts like a rude saw. Fear of Snakes in Primates.— Mr. A. E. Brown has recently made experiments in the Philadelphia Zoological Garden, in pursuance of those of Mr. Darwin. He coiled a dead snake in a newspaper, so as to be easily capable of coming loose, and set it on the floor of a cage containing a great variety of monkeys. It was instantly carried off by a leading spirit, but in a few seconds the paper became unfolded and the snake was exposed. The monkey instantly dropped it and went away, but with a constant look behind. The other monkeys, perceiving the snake, approached, step by step, and formed a circle round it six or eight feet in diameter. None approached except one Macaque, who cautiously made some snatches at the paper. At this moment a string which had been attached to the snake's tail was gently pulled ; the snake moved, consequently, and the monkeys fled precipitately, with great chattering and screaming. Some time after they gradually returned to their former position, and they continued for some hours showing both intolerable fear and a strange attraction. The same monkeys had no fear of a tortoise or a small dead alligator. The same snake was then shown to mammals of other orders, but none of them showed any especial interest. It is seen that the same dread of snakes is shared by the human species, especially women. Mr. Brown was able to trace, in the actions of a woman who was deaf and dumb, very similar fear, attraction, and repulsion to that shown by the monkeys. Is this a relic of early struggles for existence with an enemy whose bite produced results very different from that of other animals, and exposed mankind to a death lingering and horrible ? The Fertilisation of Eggs of the Lamprey. — We have frequently referred to the great progress of researches into the actual phenomena of fertilisation, especially those of Hertwig. Ernst Calberla, of Freiburg, is another most earnest pursuer of this subject, and he has followed the fertilisation of the lamprey. His views corroborate very strongly those of Hertwig, with some additional particulars. He finds a very distinct external micropyle, with a channel in the yolk leading into the ovinucleus {Eikerii), which is the residuum of the germinal vesicle. The spermatozoon which is so fortunate as to find the micropyle, enters it and gives rise to the sperm- nucleus {Sper7nakern), which appears twenty-six seconds after the entrance of the spermatozoon into the micropyle. In a minute and a half altogether, the cleavage-nucleus {Furchungskern) is seen. After five hours the first cleavage furrow arises, at the spot where the micropyle was situated. In the Zeitschrift filr wissenschaftliche Zoologie, vol. XXX. part 3, Calberla gives a most interesting account of his procedure and observations, and reviews the work of other investigators, giving a capital bibliography which is of value to those interested in such a rapidly expanding subject. GEOGRAPHICAL NOTES Admiral Sir George Back, F.R.S., died on Sunday at the age of eighty-one years. He entered the Royal Navy when twelve years old as a midshipman on board the Arethusa, and in 1818 joined a vessel under the com- mand of Sir John Franklin, whom he accompanied on his expedition overland from Hudson's Bay to the Coppermine River, having already taken part under Capt. Buchan in his perilous voyage of discovery made to the neighbour- hood of Spitzbergen. In the spring of 1825 Lieut. Back again accompanied Sir John Franklin on his second ex- pedition to the Arctic regions for the purpose of co- operating with Capt. Beechy and Capt. Parry in their simultaneous efforts to ascertain from opposite quarters the existence of a north-west passage. Full details of this voyage will be found in Franklin's "Narrative of a Second Expedition to the Shores of the Polar Sea." Back was again appointed in the spring of 1833 to con- duct the expedition fitted out for the purpose of seeking and relieving Sir John Ross, who h:-d gone out nearly four years previously in quest of the north-west passage. A full account of the results of that hazardous enterprise, in the course of which he discovered the river which has since borne his name, Capt. Back gave to the world in his "Narrative of the Arctic Land Expedition to the Mouth of the Great Fish River and along the Shores of the Arctic Ocean in 1833-35." In 1836 Capt. Back sailed in command of another expedition to the frigid zone. The details of this expedition, in the course of which he reached Frozen Strait, almost within sight of Repulse Bay, were published by Capt. Back in his "Narrative of the Expedition in Her Majesty's Ship Terror, Undertaken with a view to Geographical Disco- very, in 1836-37." In 1857 he obtained flag rank, but had not been afloat since that date. In 1837 Back had awarded to him the gold and silver medals of the Geo- graphical Society. He also was honoured by the gold 228 NATURE \Ju7ie 27, 1878 niedal of the Geographical Society of Paris, of Avhich he was made a corresponding member. He -was knighted in 1839, and elected a Fellow of the Royal Society in 1847. In the latter part of January and in February last Mr. G. J. Morrison, of Shanghai, made an interesting journey overland from Hankow to Canton. The distance in a straight line is about 525 miles, and he estimates that an ordinary route would be less than 700 miles, though by the route he took it was 860 miles. On the Avhole, Mr. Morrison does not appear to have experienced any very grave difficulty with the natives during his journey ; the people in the southern part of the province of Hupei were very civil, and not very inquisitive ; but as he got into Himan, the population of which is notoriously turbulent, he remarked a great difference. The main portion of his land journey was through a district which had not been visited by a foreigner "within the memoiy of the oldest inhabitant," and the natives — as is always the case in out-of-the-way parts of China — were most anxious to see the stranger. Mr. Morrison's great trouble appears to have been with his maps, and this was especially the the case where the provinces of Hunan and Kwangtung meet. "The Chinese maps of this district," he says, "are very incorrect, and some foreign maps are worse. The fact that along the north of Kwangtung there is a range of mountains, but that this range does not form the water- shed, has been puzzling to geographers. Ichang, which is on the south side of the pass, is still in Hunan, and is situated on the head waters of an affluent of the North River of Kwangtung. This affluent runs in a narrow gorge through the range above referred to." The country through which Mr. Morrison passed on his journey presented many points of interest. Near Wuchang, on the right bank of the Yang-tsze, the land is low and subject to floods, but a short distance to the south it becomes undulating. A little to the west of Puki, on the borders of the great tea-districts, as else- where in Hunan, a large quantity of tea-oil is made ; the plants from which the seeds are obtained grow about eight or nine feet high, and are more straggling than the tea-shrub. The Siang River, which flows through Hunan, Mr. Morrison found to be in some places nearly a mile broad ; but its usual width, when the water is low, is about one-third of a mile. At certain seasons vessels of considerable size are able to ascend as far as Changsha, the capital of the province of Hunan, which is a large and apparently prosperous place. Siangtan, a great trading- place further on, though only a third-class city, is larger than Changsha, and its population is estimated by the Chinese at one million, which, no doubt, is an exaggera- tion. In the neighbourhood of the borders of Kwangtung the country is bleak and uninteresting. The road over the Che Ling Pass, which is by no means steep, is crowded with traffic, tea-oil, tobacco, &c., going south, and salt and Canton goods going north. The absence of trees is very noticeable both in Hunan and Kwang- tung ; in the latter the traveller sees the hills for miles detiuded of every tree, but in Hunan some attempts are being made at replanting. The part of Mr. Morrison's journey which interested and astonished him most, was the examination of the coal-fields of Hunan and Kwang- tung ; but it was with very great difficulty that he obtained permission to visit one mine. He noticed that there, as in all Chinese mines, the great want was a good road, which seriously interferes with the output of coal. Amid all the disasters from flood and drought which have fallen upon China of late, the North China Herald says it is pleasant to learn that the great river which has earned the epithet of ** China's Sorrow," has not this year justified its name. The Governor-General of the Yellow River reports that the unprecedented cold of the winter caused the upper waters to freeze, and that for more than a month all traffic was suspended, letters having to be forwarded overland by circuitous routes, a necessity which has not arisen for many years, while the pressure of ice in the upper waters caused a rise of one or two feet lower down. We have already referred to the fact that relics of the Franklin Expedition have been heard of as in possession of the Nechelli Eskimo away to the west of Hudson Bay. The schooner Eothen has left New York under Capt. T. F. Barry — who was in communication with these Eskimo last year — with a party to search for and bring back the relics — among which are said to be written records. The Eothen goes to Repuhe Bay, whence a party will sledge west about 600 miles to a point near Cape Englefield, whei'e the relics are said ^to be. The expedition is expected to be away two years and a half. We have before us a number of German geographical journals, the nature of whose contents we can only briefly refer to. Indeed the number of these journals in Ger- many, and the high quality and variety of their contents, are remarkable ; they forcibly illustrate the often-repeated saying that geography has become the meeting-place of all the sciences. First, we have advanced sheets of the July number of Petermann's ever-welcome Mit- theilungen. The first article is by Dr. van Bebber, on the distribution of rain in Germany during the four quarters of the year, and is illustrated by four maps, A remarkably picturesque preliminary, but lengthy, account of his travels in the Caucasus in 1876, is con- tributed by Dr. Gustav Radde, whose observations on the botany of the region are valuable. Dr. Wojeikoff has an important article on the results of the recent Siberian Surveying Expedition, and Dr. Brehm con- tributes his usual admirable monthly summary. From the Berlin Geographical Society we have Nos. 3 and 4 of the Verhandltmgen zxid Nos. 74 and 75 of the Zeit- schtift. In the former the principal paper is an ac- count of Thielmann's recent ascent of Cotopaxi, and a long and learned paper by Baron von Richthofen on Prjwalsky's recent journey to Lob-nor. In the Zeitschrift (No. 74) is a paper (with map) on the distribution of rain in Europe, by Dr. Otto Krilmmel, and a paper of great interest, also with a map, by Dr. Theobald Fischer, on the changes in level of the Mediterranean Coast j the map shows at a glance what parts of the coast are rising and what parts are sinking. No. 75, apropos of the recent jubilee of the Society, has a long and inte- resting account of the progress of geography during the past fifty years, especially in connection with the work done by the Society. This is followed by a paper, with map, on the ethnography of Epirus, by Dr. Kiepert. In the Mittheihtngen of the Vienna Society the two- principal papers also relate to the East ; one (a continua- tion) being on the Turkish Vilayet of the Islands, by A. Ritter von Samo, and the other being an important con- tribution to Turkish ethnology by Herr Carl Sax, Austrian Consul at Adrianople. The paper and map of the latter show both the race and religion and language of the various divisions of the country, three items which are often confounded. The Japanese are certainly making great strides in the way of harbour improvement and the extension of means of inland communication, affording thereby a direct con- trast to the exclusiveness and obstructiveness of the Chinese. The Doboku-Kioku (Bureau of Construction) now propose to construct a harbour at Samusawa in Miyagi, at a cost of 350,000 yen. It is also said that the Japanese Government desire to raise a home loan of 10,000,000 yen for the purpose of connecting Lake Biwa, in the province of Omi, by a canal with the river Uji, to bring the waste lands in the province of O-u under culti- vation, and in order to connect Kioto with the Bay of Tsuga by railway. June 27, 1878] NATURE 229 REAL BROWN BREAD NOTWITHSTANDING the labours of chemist and physiologist, the exact composition and nutritive value of the several products obtained in milling wheat have not been thoroughly determined. That fine flour contains less nitrogen, and leaves, when burnt, less ash than biscuit flour, middlings, or any variety of bran, is well known. The percentages of starch, of the mixture of cellulose and lignose known as "fibre," and of fat, in several series of samples of mill-products, have been ascertained. Moreover, there have been made many minute analyses of the ash of wheat and of the prepara- tions derived from it. But we are still somewhat in the dark concerning both the chemical and physiological aspects of what may justly be regarded as the central feature of the problem under discussion. For we are not sure of the nature of the nitrogen compounds which exist in the several distinct parts of the grain of wheat ; nor do we know how far the phosphates and such nitro- gen compounds as may be ranked with the true albu- Flour. C minoids can be digested when intimately associated with fibre. Then, too, the mechanical condition of these coarser products from the milling of wheat is of consider- able moment in estimating their actual value as nutrients. Before endeavouring to reach some conclusion as to the comparative merits of white bread, brown bread, and whole-meal bread, I will offer in as compact a form as possible the more important and incontrovertible data which must form the starting-point of the discussion. Firstly as to variations in composition in the grain itself. These variations, chiefly affecting the percentage of nitrogen, depend upon hereditary qualities in different strains of the wheat-plant ; upon climate and season ; and, to some extent, but not so largely as is often stated, upon cultivation, soil, and manure. The hard translucent wheats, blh durs et glacis, of high specific gravity, about 1*41, and, owing to their lengthened and wrinkled shape, of low weight per bushel, these wheats are rich in nitro- gen. The soft opaque wheats, of less specific gravity, about I "38, and, owing to their rounded and plump form, of high weight per bushel, these are poor in nitrogen. Brak. Nitrogen °,', Ash °, Nitrogen */, The hard wheats grown in Poland, in Southern Russia, in Italy, and in Auvergne, are used in the manufacture of macaroni, vermicelli, semohna, and pates d'ltalie. The softer and more starchy wheats are especially appropriate for the production of fine white flour. According to the most recent analyses, the percentage of nitrogen in different varieties and samples of air-dry wheat may range from i"3 up to 2'5 — numbers corresponding to 8*23 and 15*83, respectively, of gluten or flesh-forming substances. But the same variety of wheat may give a grain having 3 per cent, more gluten in a bad season than when matured in a fine summer. More than this, one may select from the same field, the same plant, or even the same ear, indi- vidual grains which shall show quite as wide a variation in gluten, as that just cited. For instance, a sample of Hallett's white rough-chaffed wheat of the harvest of . 1865 contained many dense and translucent homy grains having I3'2 per cent, of gluten, while the white opaque soft grains from the same sample contained but 9*6 per rent. It will simplify the consideration of the chemistry of mill-products if we confine our attention mainly to the nitrogen and ash of the grain. The following diagram represents the percentages of these two substances in a series of flours and brands derived from a good sample of English soft wheat. The figures are based in great measure upon the analyses made at Rothamsted by Dr. Gilbert. The mill-products termed A, B, C, are derived mainly from the central portion of the grain, and con- stitute "fine flour;" D is a biscuit flour known as "tail- ings ; " E is intermediate between flour and bran, and goes under the name of "middlings;" F is "coarse sharps," G "fine pollard," H "coarse pollard," and I "long bran." K, or thin bran, is a product obtained in the process of decorticating wheat by attrition; while L is separated from the grain by moistening and then rubbing it, as in the method devised by M^ge Mouri^s. These two latter products may legitimately find a place in the series, since they represent the last terms as we proceed towards the outer coats of the grain. The above table explains itself ; we would remark merely that both nitrogen and ash are lowest in the four 230 NA TURE \yune 27, 1878 flours, and thattheformer constituent attains its maximum in F, the coarse sharps, and the latter in 1, the long bran. In K and L both nitrogen and ash are lower, these pro- ducts containing much cellulose, made up as they are in great measure of the three coats which form the pericarp of the grain. But it must not be forgotten that all the mill-products included under "bran" contain much more cellulose than is present in flour, namely : — from 7 to 15 per cent., or even more, in lieu of i per cent., or less. And it would appear that while flour contains more than 90 per cent, of its nitrogen in the form of true albumi- noids or flesh-formers, in some of the brans one-third of their nitrogen is in the form of non-albuminous bodies, of no recognised value as nutrients. We have now to secure but one more datum before we proceed to the determination of the main question before us. How much flour and how much bran will 100 parts of ordinary soft wheat yield on the ordinary system of low-milling adopted in England ? As the averages from an immense number of independent estimates we may put down the flour at a total of 80, the bran at 17, and the loss at 3. Thus, from an economical point of view, we appear to lose \, or twenty per cent, of our wheat by submitting it to the numerous treatments involved in the manufacture of flour. But is this really the case ? We think not. For much of the nitrogen in the rejected parts is not in the form of flesh-forming matter, and much that does so exists in the bran passes unaltered and unused through the alimentary canal, because of its close incorporation with fibre. But on the other side we must not forget that bone-forming materials are clearly deficient in wheaten flour, and that those phosphatic compounds present in bran are readily soluble to a large extent, not only in the several digestive secretions with which they come in contact in the body, but also in pure water. But in comparing and contrasting bread made from flour with that made from whole wheat we must con- sider other points. ■•■ We shall find it impossible to make, by means of leaven or yeast, a light spongy loaf from whole wheat finely ground, the so-called cerealin of the bran inducing chemical changes wliich result in a moist, clammy, dense product. Even whole wheat merely crushed into meal, and not ground, partakes of the same defect. Fine' flour, on the other hand, yields a bread which is light enough before mastication, but which, when masticated, possesses a maiked tendency to become compacted into dense lumps which may never become penetrated by the gastric and intestinal juices, and which are a frequent cause of constipation. ' Whole meal bread cannot be charged with this defect ; indeed it acts medi- cinally as a laxative, and by reason of its mechanical texture is hurried rather too quickly along the digestive tract, so that the full virtue of such of its nutrients as are really soluble becomes in part lost. Yet there is no doubt that for many persons, especially those who have passed middle age and are engaged in sedentary occu- pations, whole wheaten meal in the form of bread, biscuits, scones, &c., forms an invaluable diet. The following analyses may present some of the fore- going statements in a clearer light and may add some additional particulars of interest. They represent, so far as a couple of sets of average results can do so, the per- centage composition of ordinary white bread and of the whole meal bread made by Mesrs. Hill and Son : — Water ^ Albuminoids or flesh -formers Starch, dextrin, and sugar Oil and fat Cellulose and lignose ... ^ Ash or mineral matter White. 40*0 7-0 0-6 o'5 I"2 Whole Meal. 43 '5 "10-5 40*6 1-6 1-8 2*0 • Calculated from total nitrogen present. As much as i2'5 in s )me samples. 3 Includes comman salt added. It is clear from the above figures that if we could reckon the whole of the nitrogenous matter in whole meal bread as equally effective with that contained in white bread, we should possess in the former a far more perfectly adjusted food ; for the ratio of flesh- formers to heat-givers is about i to 74 in white bread, while it approaches i to 4 in some samples, at least, of whole meal bread. Add to this the higher proportion of phosphates in the latter, and its chemical superiority over white bread becomes still more marked : its flavour, too, is far richer. One word as to ordinary brown bread will suffice. It is a poor preparation at the best. By adding a dash of rather rough bran to flour we do not obtain a satisfactory or rich product : analysis demonstrates this fact clearly. We cannot leave this subject without referring to the little pamphlet which Messrs. Hill and Son have recently issued,^ on the subject of wheaten meal. Though its main purpose is necessarily a commercial one, it presents many interesting and important facts in a readable form. Messrs. Hill have certainly brought their specialty in bread making some way on the road to perfection. With a few of the opinions in their little brochure we cannot, however, wholly concur ; nor do we see how their asser- tion can be maintained that the present system of white bread making involves the loss of 50 to 60 per cent, of the wheat devoted to that purpose. The limited space at our command must be our ex- cuse for the very imperfect treatment here adopted of the wide subject before us. A. H. Church TJfE LAND OF BOLIVAR AND ITS PRODUCTS^ VENEZUELA, or the Laijd of Bolivar, as Mr. Spence prefers to call it, has certainly received less attention from European travellers than many other less attractive and more explored parts of South America. The Andean ranges of the north and the llanos of the south of the repubhc alike merit attention, and now that mining enterprise has opened up several parts of the country and tinged it with European civilisation, w^e know of no more come-atable country to which the naturalist could turn his steps. Certain it is that he would find ample materials for investigation, and reap a good harvest of novelties in either fauna or flora. Mr. Spence' s main object in visiting Venezuela was, as it appears, the obtaining of a concession of the privilege of working certain deposits of mineral phosphates in the Roques Islands on the northern coast of the republic. During the eighteen months occupied by the delicate negotiations required for this purpose Mr. Spence seems to have lost no time. Although nominally resident at Caracas, in order to be in immediate communication with the ministers, frequent excursions were made to the most interesting of the surrounding districts. The coal mines of Nueva Barcelona, the Lake of Valencia, and the group of islands which were the seat of the wished- for concession, besides other localities of interest, were visited and explored. But the ascents of the Silla of Caracas and the still higher peak of Naiguatd, the crown- ing point of the Andean range between Caracas and the coast, appears to have been the principal expeditions to which Mr. Spence devoted his attention. The first 1 "The Whole Meal Bread Question." By W. Hill and Son, Bishops- gate Street. * ' ' The Land of Bolivar : or, War, Peace, and Adventure in the Republic of Venezuela." By James Mudie Spence, F.R.G.S. 2 vols. 8vo. (London, 1878.) "Estudios sobie la Flora y Fauna de Venezuela." Por A. Ernst. 4to. (Caracas, 1877.) ' Estudios sobre las deformaciones, enfermedades y enemigos del Arbol de Cafe en Venezuela." Por A. Ernst. (Caracas, 1878.) " On Venezuelan Birds Collected by Mr. A. Goering." By P. L. Sclater, M.A., F.R.S., and Osbert Salvin, M.A., F.R.S. {Proceedings of the Zoolo- gical Society of London, 1868-75. Five articles.) June 27, 1878] NATURE' 231 recorded ascent of the Silla was made by Humboldt at the beginning of the present century, since when it has been climbed by several enterprising Venezuelans and by some foreign visitors. Mr. Spence effected the ascent in April, 1 872, in company with the German naturalist, Goering, who was at that time collecting in Venezuela, and several private friends. The Silla having been successfully stormed, the summit of Naiguatd, which rises about 800 feet higher, was the next object. From the Silla, Mr. Spence tells us, this high peak " rose boldly to view, and the walled-in appearance of its flanks provoked not only curiosity, but an enthusiastic desire to overcome its tra- ditional difficulty of ascent." Now Naiguatd was reputed to be inaccessible ; there was a firm belief in Caracas that its summit " would never be trodden by human foot." There was even an old tradition which " proclaimed its impregnability," and all those who had attempted to scale the height had been compelled to abandon the undertaking without success. Nothing daunted by the objections of the good people of Caracas, Mr. Spence and his friends set out on their exf)edition on April 21, 1872, and arrived, after some httle difficulty, at the desired summit about midday next day. The Grand Precipice (see our illustration, Fig. i) would not perhaps appear very formidable to an Alpine-clubbist, but under the tropics people are not so active or so ven- turesome as in these cold climes, and the retreat was rendered rather severe from the want of water, and the fog which rose up in the evening and obscured the way, as shown in Mr. Spence's drawing (Fig. 2). How- ever, the deed was done, and amongst a small collec- tion of Alpine plants brought from the summit, which has been since described by Dr. Ernst in the Journal of Botany,^ was a new species of bamboo, named, after its discoverer, Chusqiiea spencei, in commemoration of the occasion. Besides the account of his various expeditions and of his life at Caracas, many miscellaneous subjects regarding Fig. I.— The Grand Precipice of Naiguata. the "land of Bolivar" are treated of in Mr. Spence's volumes, and the appendix contains other details, amongst which is a synopsis of the orchids hitherto met with within the confines of the republic from the pen of Dr. Ernst. On the whole we may pronounce that Mr. Spence has done well in bringing the merits of a little-known part of the world's surface before the European public. Could Venezuela be persuaded to keep free from intestine dissen- sions, and to pay her debts a little more regularly, she might still make a figure among the American republics. Along with Mr. Spence's volume two memoirs of Dr. Ernst, whose name we have already mentioned, lie before us. Dr. Adolf Ernst is, as his name betrays, a German who has deserted the Fatherland for Caracas, and is there labouring to grow science upon a somewhat un- congenial soil. In botany, zoology, and ethnology alike he has worked hard, and is the founder of the " Sociedad de Ciencias Fisicas y Naturales de Cardcas," and, we Flc. 2. — The Way lost on Naiguata. believe we may add, the writer of the greater part of the memoirs of that learned association. His first "Estudios" contains general essays on the flora and fauna, and special catalogues of the ferns, orchids, birds, and land-molluscs of the republic. The second " Estudios" are devoted to a subject of primary importance in Venezuela, that is, to the maladies and enemies (animal and vegetable) of the coffee-plant — one of the staple-products of that part of America. This appears to have been written in answer to an appeal, from the scientific society above-mentioned, for the best essay on this absorbing question, and received the prize to which it was, no doubt, entitled, as having been written by probably the only individual in Venezuela who had more than empirical knowledge of the subject. Finally we may remark that there is at least one ' " Notes on a Small Collection of Alpine Plants from the Summit of NaiguSta, in the Mountains of Caracas," By A. Ernst, Ph.D., &c. {jfour. Bot., September, 1872.) 232 NATURE {June 27, 1878 branch of the fauna of Venezuela that appears to have been pretty thoroughly worked at, Herr Anton Goering — the German naturalist, whose name has been already mentioned in connection with the ascent of the Silla of Caracas — sent all his collections of birds to this country, where they were examined and reported upon by two competent naturalists, who have devoted special attention to the neotropical avifauna. The results are given in the series of papers read before the Zoological Society of London, of which the titles stand last in our list of the subjects of this notice. Mr. Goering' s principal discoveries in the class of birds were made in the Andes of Merida, where some splendid novelties were obtained. And in this part of Venezuela, if we mistake not, there remains most to be done as regards both the fauna and the flora of the republic. THE FISHERIES OF BRITISH NORTH AMERICA 1 11. THE careful inquiries that have been recently carried on by various able investigators in regard to the habits of our chief food-fishes — the Cod, the Herring, and the Mackerel — have now finally disposed of a large accu- mulation of popular fallacies on the subject of their migrations. On the European side Dr. G. O. Sars has added most to our scientific knowledge of the subject ; and on the American, the United States Fisheries' Com- missioner, Prof. Spencer Baird, and Mr. Hind, of the Halifax Fishery Commission, whose reports furnish a most valuable body of information as to the New England and Dominion fisheries. It may now be affirmed with certainty that the notion of the long and distant migrations of these food-fishes is a complete mistake : the real facts being that they never range to any great distance from their ordinary habitats; that their migrations, which have reference to food on the one hand and to the deposit of spawn on the other, are simply from deep to coastal waters, and back again ; and that these migrations are chiefly dominated by tem- perature. Commencing with the Cod, we are informed by Mr. Hind that the total average weight caught in North American waters is about 185,000 tons, representing from 150 to 175 millions of fish, or between three and four times the produce of the whole Norwegian cod- fishery. Of this, the portion caught in the waters of the United States is only about one-fifth. "Winter cod" are taken on the southern coast of Newfoundland through the whole winter, while " summer cod " are captured through the summer months on the north-east shores of Newfoundland, the entire shore of the Gulf of St. Lawrence, and along the Labrador coast as far north as the Moravian missionary stations, Nain and Okak (57^° N. lat.). It seems now well established that the great body of cod-fish inhabiting the waters of the long North American seaboard is divided into numerous separate " schools," which vary in their habits according to the localities they respectively frequent, each keeping (for the most part, at least) within its own limited range. There is no specific or even varietal difference between the "winter" and "summer" cod; their movements towards the coast from the neighbouring deeps, in which they spend the remainder of the year, being determined by the climatic changes which make the northern shores afford the tem- perature most congenial to the species in the summer months and the southern in the winter. The food which lures the cod towards the shore at stated periods varies with the locality and season, being ' Continued from p. 172. - ■ for the most part the capelin in the colder seas and the herring in the warmer ; and hence the movements of these fish exert an important influence over those of the cod. At other times the chief food of the cod consists of the Invertebrates of the sea-bottom ; and according to the predominance of any particular species will be its share in their maintenance. Thus in some places the cod feeds chiefly (as is shown by examination of the contents of the stomach) upon bivalve or univalve Mollusks ; in others upon crabs, shrimps, and yet smaller Crustaceans ; in others upon sand-stars, brittle-stars, holothurians, and other Echinoderms. The resort of cod to " banks " seems essentially determined by the food they find there; this, again, being dominated by temperature, — for, as already pointed out, the water on these banks is colder than water at the same depths elsewhere : many sub- arctic species of shell-fish, &c., which serve as food to the cod, thrive there far south of their ordinary habitats (as has been observed by Dr. J. Gwyn Jeffreys on the Dogger Bank); and thus, as Mr. Hind remarks, these banks bear the same relation to the surrounding sea area with regard to certain forms of marine life, as do the oases in the desert to various species of land animals. An impression haS prevailed among fishermen, and even among naturalists, that the Shore cod, or cod gene- rally caught in coastal waters, is specifically different from the Bank cod, which is taken on reefs and banks in comparatively deep water, and often at a considerable distance from land. But it has been conclusively estab- lished by the careful observations of the two Profs. Sars (father and son) that no such specific distinction exists, the difference being one partly of age and partly of habitat. The two and three-year old cod remain on the Norwegian coast all the year round, and it is usually not until they attain their fourth year that their reproductive organs are sufficiently developed for multiplication. The adult Norvregian cod, according to Sars, retire far from the coast when the spawning season (January to March) is over ; and are found during the summer on the slopes of the Polar Deeps. So the cod which frequent the coasts of Labrador through a great part of the year, seem to be immature (though sometimes having their reproductive organs developed) ; and when they attain their full growth, which occurs in their fourth year, they change their habits, frequenting the outside banks, and only a portion of them visiting the coast during the capelin season. According to G. O. Sars, the Norwegian cod has no regular spawning ground, but drops its spawn free in the sea at a considerable distance above the bottom. The spe- cific gravity of the ova is slightly below that of sea- water, so that the spawn rises to the surface and floats there, unless the salinity of the surface-layer be lowered either by rain- or by river-water, in which case the ova sink until they reach more saline water. The same is the case with the milt of the male, which seems to be shed at a greater depth than the roe of the female, which is thus impreg- nated from beneath, the micropyle of the ovum being located at its lowest point. The time required for hatch- ing is about sixteen days, but a further period of fourteen days is required for the absorption of the yolk-bag, up to the completion of which process the young fish has little swimming power. On the North American coast the spawning of the cod is not confined to a particular season, the process taking place in one locality or another through nearly, if not quite, every month in the year, and being obviously dominated by temperature, for it appears that cod ova find the coldest surface-water, provided it be free from ice, the most congenial to their development. Hence, as Mr. Hind justly remarks, the zone of cold water of from twenty-five to thirty miles broad, which extends for hundreds of miles along the Labrador coast, within the line of banks on which icebergs ground, is a most June 27, 1878] NATURE 233 valuable possession to us, as supplying the most favour- able conditions for the development of the cod ova furnished by the South Labrador schools, and thus feeding the great fishing-grounds further south. Of late years the salted roe of the cod has become an important article of export, and the preparation of it a considerable industr}', the principal use to which it is applied being for bait. Now in so far as this utilisation turns to account what was previously thrown away as offal, it is clearly an advantage ; but it now leads to a special search for the gravid fish, which are taken in large quantities in shallow waters by seine nets, and in deep by the " bultow." This practice is very strongly reprobated by the United States Commissioner, who justly remarks that it is " precisely equivalent to killing off all the mature hens in a farm-yard before they have laid their eggs, and then expecting to have the stock continued indefinitely." "As well," he continues, "might the farmer expect to keep up his supply of wheat year by year while he con- sumed all his grain, reserving none for seed, and without the possibihty of obtaining it from any other source." It is obvious from v/hat has been already stated that the fisheries of New England must be much more injured by such a practice than those of the Dominion, the recruiting- ground of the former being far smaller in proportion ; and it is also clear that the concession to the United States fishermen of the right to carry on this industry in British American waters is a very valuable one, and that, if made at all it should be placed under conditions which may prevent its being used to the detriment of our own fisheries. The habits of the herrhig 2iX&'\n many respects different from those of the cod ; for while the latter is essentially a bottom-feeding fish, the former is an essentially pelagian fish, feeding and s-vimming either at the surface or at any depth at which it finds its best supply of food. This consists sometimes of smaller fishes — sometimes the young of its own kind, but generally speaking of more minute animals, especially Entomostraca and Radiolaria, of which small reddish-brown aggregations, known to Nor- wegian fishermen as aat, are often found floating in the waters frequented by the herring. (I have myself met with these in considerable quantity near the Shetlands.) The old notion of the annual migration of the herring from polar to southern waters has been long since aban- doned, in favour of that which recognises in its movements an instinctive direction towards shallower waters at the spawning season. The eggs do not float, like those of the cod ; but sinking in virtue of their greater specific gravity, attach themselves by their viscid envelopes either to the bottom or to anything else with which they come in contact. Ropes drawn through herring-spawn, or merely lying where it is deposited, become so thickly coated with it as to resemble large cables ; and nets let down upon the spawning-grounds become so thickly covered, that in cleansing them the decks of the fishing- vessels are often ankle-deep in spawn. This spawn is very attractive to cod, which are thus lured towards the shore by the abundance of bottom-food left by the spawning "schools " of herring, as well as by the oppor- tunity of preying on the schools themsfelves. The productiveness of the herring fishery of the British North American coasts has been rapidly aug- menting of late years, and seems likely to undergo a yet larger increase ; for while it has hitherto been prosecuted only when the fish approach the coast at the spawning season, the knowledge now acquired of its habits will guide the fishermen Avhere to look for it at other parts of the year, and how to take it at different depths. The limit set by temperature to the southern range of the herring has been already adverted to ; and the admission of United States fishermen to British American fishing grounds is likely to become an even greater boon to them, in allowing them to prosecute a winter herring fishery along the coasts of Nova Scotia and Newfoundland, than it is in enabling them to participate in the cod-fishery, "The fluctuations in North American waters," says Mr. Hind, *'are small in extent compared with those astonish- ing changes which take place in Europe, sometimes causing the ruin of large commercial and fishing com- munities, and leading to general distress. But the permanency of the herring schools in British American seas, the comparatively small size of the schools, and their uniform extent of distribution over an immense extent of coast-line, give them a direct and individual value to our fisheries, greater than is enjoyed even in Norway." The spawning of the herring on British American coasts takes place partly in May and June (this being known as the " spring spawning "), and partly in August and September (the "autumn spawning''). The spring and autumn "schools" appear to be quite different ; the period being determined in each case by the temperature of the w-aters frequented by the school. The spring spawning takes place with great regularity on the breaking up of the ice. The young when hatched school together, rarely going out to sea as far as their progenitors, and wintering by themselves apart from the older fish ; not being found in any numbers in the deep bays of the coast of Newfoundland, Nova Scotia, and the northern part of Maine, where the old herrings winter. It seems probable that they do not begin to spawn until they have attained their third or fourth year. The depth at which the " spawning grounds " lie varies considerably — on the Norway coast, according to Boeck, from 10 to 150 fathoms. And there is good reason to believe that the occasional abandonment of old spawning grounds is usually due to a change of temperature, and that the fish is to be found at no great distance, probably in deeper waters. " It is an important result of scientific inquiry," says Mr. Hind, "to ascertain the extent of the movements of a class of animals which have suddenly disappeared from accustomed haunts, and thrown into hopeless confusion an enormous industry upon which hundreds of thousands are dependent for their daily bread. But what imme- diate relief does it afford, if the discovery establishes the fact that the small downward movement into deeper water, or outward movement into less accessible wintering or spawning grounds, has placed them within reach of fishermen provided with the requisite means of capturing them?" In adapting themselves to such new require- ments, he considers that the United States fishermen show more energy than those of New Brunswick ; but if the latter allow themselves to be beaten in this winter fishing, in spite of the advantages given by nearer proximity to the fishing-grounds, it is of course their own fault. The Norwegian herring fishery has of late suffered such a decline, while that of the North American coast has been improving, that out of the million of barrels, to which the catch of the latter is said to amount, no incon- siderable amount is now carried to Sweden in United States vessels. Another source of profit in the capture of the herring is the manufacture of an oil pressed from the bodies of the fish, and the use of the residual "scrap" as manure, under the name of fish-guano. And a vast number of freshly-caught herrings are used as bait in the cod and hahbut fisheries ; the United States fishermen resorting for this purpose to the Nova Scotia and New Brunswick fishing-grounds, as they find a more profitable market at home for the herrings which they catch off the New England coast. There is reason to fear that, unless due attention is given to the preservation of the spawning grounds, the New Brunswick herring-fishery will decline as that of New England has done ; so that the activity of the United States fishermen will not only greatly injure British interests, but will in time come to defeat 234 NATURE Sjfune 27, 1878 their own, if it be not placed under provident restraint. Not only the fishermen of the United States, but those of France also, are supplied with cod-bait from the New- foundland herring-grounds; and from recent arrange- ments for storing the bait-fish in ice, the capture of herrings for this purpose is being carried on with in- creased vigour. " So urgent is the demand for bait, and so entirely dependent are the cod and halibut fisheries upon a sufficient supply, that the fisheries may be said to be altogether dependent upon its being available, either naturally or stored near at hand, in a fresh and suitable condition." "The importance of these facilities for pro- curing bait only stands out in its true relief, when com- pared with what would be the condition of affairs if the fishermen of the United States did not enjoy a sufficient supply." The Capelin and Launce, also, though of comparatively little value as human food, are of great importance as bait-fishes ; the former supplying the cod fisheries of Labrador (where they sometimes abound to such a degree that at the spawning season their shoals are often stranded along the shore), and coming south as far as the Grand Banks ; whilst the latter often visit the Banks in such enormous numbers as to give to the sea quite a glittering aspect. The resort of capelin to the New- foundland fishing-grounds is less regular than that of herring, and it has been found necessary, in order to prevent the destruction of this most important attraction to the cod, to prohibit the use of capelin as manure. The Mackerel is another very important food-fish, which, though an inhabitant of the United States coast much further south than the herring, is especially abundant in northern waters, and has always formed an important component of the produce of the Dominion fisheries, the value of the catch in some seasons exceed- ing that even of the cod. The supposed migrations of the mackerel from warm southern waters to cooler seas during the summer months, like the mythical wanderings of the herring to polar seas during the winter season, or the equally fanciful migrations of the cod to spawning- grounds on the Norwegian coast, have disappeared before the test of rigid inquiry; the fact being that different schools of mackerel inhabit different parts of the western shore of the Atlantic, from Greenland to Cape Hatteras ; wintering in deeper water, and approaching the shore in the spawning season. The time of this approach varies with the temperature of the locality, the fish making their appearance earliest in southern latitudes, and progres- sively later in the spring and summer in proportion as the latitude is higher and the temperature of the sea lower. The spawn is not deposited on the bottom like that of the herring, but floats on the surface like that of the cod ; and the young, when hatched, seems to pass the earlier part of its life in coastal waters. Though the schools of mackerel wander a good deal in the summer months, their wanderings do not appear usually to extend far from their birthplace, and seem mainly to have refer- ence to food-supply, which consists of small fish-fry, entomostraca, and other inhabitants of surface-waters, the relative abundance of which is greatly determined by prevalent winds, while the stratum in which they swim is mainly determined by temperature. For this and other reasons not yet fully known, the fluctuations in the productiveness of the Mackerel fishery are much greater than those of the Cod and Herring fisheries, especially on the New England coast ; and thus the unrestricted admission of United States fisher- men to the Dominion waters is a privilege of great value, of which they have largely availed themselves. Mackerel- catching is a special industry, and requires sea-going vessels. The boat-equipment common throughout British- American waters is wholly unsuited to the pursuit of the mackerel, immense schools of which are frequently left unmolested in the Gulf and on the coasts of Newfound- land, in consequence of the fishermen being unprovided with suitable vessels and fishing-gear.^ Hence the greater part of the mackerel fishery in these waters has hitherto been carried on by United States fishermen ; but there is, of course, no reason, save a want of enter- prise, why those of the Dominion should not prosecute it with equal success. From all this it is clear that if the United States fisher- men were limited to their own waters, they would speedily exhaust the supplies of the " commercial fish " required not merely for the supply of food to a vast population, but for the supply of bait, fish-oil, and fish-guano — toge- ther constituting a drain which far exceeds the natural resources of the limited area along the United States coast inhabited by the cod and other deep-sea fish, as is fully admitted by Prof. Spencer Baird, the United States Commissioner. And thus the free admission of United States fishermen to the fisheries of the Dominion, which are not only unexhausted but apparently inexhaustible (if only placed under reasonable restrictions), is a privilege of enormous value, which should be met on the other side in a spirit of fair reciprocity. How far this spirit has been exhibited on the part of the Legislature of the United States — which, after agreeing to an arbitration for the settlement of the amount to be paid in compensation, is now raising technical objections to the award, and protesting strongly against its justice, — is not a matter for our consideration ; but we cannot conclude without adverting to one point which seems to have received insufficient attention. While the coastal waters of the United States are in great measure unfitted by temperature for the mainten- ance of the "commercial" fishes, they are peculiarly adapted for the natural growth and artificial production of different species of shell-fish ; some of which are chiefly useful as bait, whilst the Oyster not only supplies the wants of American consumers, but has become a large article of export. The Oyster-industry in the United States now far exceeds in value the aggregate of the deep-sea fisheries ; its head-quarters being Chesapeake Bay, " a magnificent basin in which Providence seems to hare accumulated every necessary condition for forming an admirable locality for the fishery," so that the oysters inhabiting it do not need culture, but are at once fit for the market. The transport of these oysters to the Northern and Eastern States employs quite a fleet of schooners ; and the amount of oyster-shells calcined for Ume is almost incredible, the profit derived from the shells at Baltimore alone amounting in 1857 to more than 120,000 dollars. Now the Treaty of Washington having limited the taking of shell-fish to the citizens of the nationality in which they are found, British American fishermen are completely excluded from the Oyster-industry of the United States, without possessing any corresponding advantage ; for the temperature and other conditions of the Dominion coast are just as ««favourable to the growth of oysters and other esculent shell-fish, as those of the United States coast are favourable ; so that, as its produce has no com- mercial value, "the reciprocity is all on one side." The different fisheries of the United States coast have been long pursued with the ability and energy which distinguish the American people ; but it has been clearly pointed out by the officers employed both by the United States Government and by the several States' Govern- ments, that a decline in the productiveness of the fisheries has of late been going on along the greater part of the coast, and that this decline is due to excessive capture, especially of spawning fish. Through the obstruction and ' It is worth notice that the abundance of mackerel on the north-east coast of Newfoundland was for many years so great, tha' t"^ "*•» were nat only used for manure, but gave such trouble to the tishermen engaged in the cod and herring fishery, that their subsequent dimmution was lattributed by the fishermen to their having been ' cursed ofl the coast. yune 27, 1878] NATURE 235 pollution of the New England rirers, the lumberer and manufecturer have ruined the cod-fishery of that locality by destroying the anadromous fishes which attracted the cod thither ; so that thus the " fish oil ' ' and " fish guano ' ' manufacturers, who are now enriching themselves, not only at the expense of the herring and menhaden, but of the other species which depend on these for food, will speedily, if unchecked, increase the depletion of the northern waters of the United States ; thus increasing the value of the concession made by the Treaty of Washing- ton, and rendering it still more important that laws should not only be made, but enforced, for the prevention of a similar depletion of the (at present) highly productive fishing-grounds of the Dominion, William B. Carpenter THE GEOLOGY OF LONDON^ A LTHOUGH the British Government have under- -'*• taken the geological survey of the country, yet the valuable results obtained by this survey are unfortunately allowed to remain almost unknown to the general public. A complete set of the publications of the geological sur- vey costs, we believe, something like 130/., and is, of course, quite out of the reach of all but great libraries and wealthy public institutions, and no authorised reductions of the maps have as yet been published. It is much to be regretted, too, that the illiberal parsimony displayed in some branches of our public service is most conspicuous of all in that scientific department of it, where its effects prove most injurious. While the publications of the American geological surveys are distributed in foreign countries with an open-handed liberality worthy of a great govern- ment, and the courtesy of the chiefs of those surveys, Dr. Hayden and Mr. Clarence King, is well known to every- one— it is notorious that the directors of our own survey are placed in the painful position of having to refuse to acknowledge the just claims of the largest and most im- portant scientific institutions of their o^vn and other countries. The directors of our national surveys are the more to be pitied, inasmuch as the position of grudging parsimony in which they are placed contrasts so strikingly with that course of wise and judicious liberality in making known the results of their labours which the officers of the scientific departments of the United States and some other countries are permitted to pursue. Another matter calling for serious consideration on the part of those who manage the publication of the results of these national surveys, is the exorbitant prices so often charged for the maps and memoirs. We know not whether it be the result of mismanagement or some- thing worse, but it is a fact that it would seem to cost this Government department three or four times as much to produce a map or memoir as a private firm would require to accomplish the same work. Surely these publications not being handicapped with the charges of authorship, ought to be alike marvels of cheapness and models of excellence, yet how very different is the fact ! For an unmounted one-inch map of the district around London the public is charged thirty shillings; for very mode- rate-sized volumes printed on inferior paper and having the general aspect of mean blue-books put into cloth covers, the sum demanded is two pounds ; and recently the geological survey has surpassed even itself by issuing a small paper-covered pamphlet at the price of seventeen shillings ! None suffer so much from the effects of this unwise parsimony and obvious mismanagement as the officers of the survey itself. Those among their number who are engaged in active scientific work see the results of their ^^ Stanford's Geological Map cf London and its Suburbs. The Geoloey ^Tr A w T '"l^ ^'""P" ^o'* °i^^I "^^^^ °f t*^«= Geological Survey of En^- land and Wales by James B. Jordan. Size, 76 inches by 65. Scale. 6 inchfs to a nule. (London : Edward Stanford, 1878.) labours, after long delays and many vexations, placed before the public in an almost inaccessible form ; and they are too often disappointed and discouraged by finding that they do not receive the credit which their persevering labours so well deserve. Possibly, as has frequently happened, an amateur observer working inde- pendently, and untrammelled by the chains of officialism, IS able to forestall their results, by publishing in a scien- tific journal the most important of their conclusions. Have not the directors of these surveys yet learnt that the day is gone by, when scientific writings can with impunity be delayed for years in the press ? Fortunately the evils to which we have directed atten- tion in the foregoing paragraphs have a tendency to work their own cure. Thus, though the English Government have not followed the wise example of Austria in pub- lishing chromo-lithographed reductions of the larger maps, the director-general and the directors of the branch surveys have produced privately useful maps on a reduced scale of the areas of which they respectively have charge. Objectionable as it may seem in principle that Govern- ment officials should issue as private speculations these results of their labours, it is certainly better that they should be allowed so to do, than that the public should be altogether deprived of such important publications. The map of which the appearance has prompted the fore- going remarks, is another example of private enterprise, being allowed to take in hand what we might fairly expect to be accomplished by a national institution. At the Loan Exhibition of Scientific Apparatus, in 1876, a MS. map of the geology of the district around London, drawn on the scale of six inches to the mile, attracted much attention. Since that time this map, with a well-constructed model of the same area, has formed one of the attractions of the admirable museum at Jermyn Street. In this in- stance the wise course was adopted of publishing a cheap " Guide to the Geology of London," which was drawn up by Mr. Whitaker, one of the most active and efficient officers of the survey, and a geologist whose researches, are well known to scientific men beyond its limits. We believe that this excellent little book has had the large circulation it so well deserves ; and it is certainly much better calculated to attract the attention of the general public to the important work that is being carried on by the Geological Survey than some of the more ponderous volumes, of which only a few copies are sold at very high prices in each year. But valuable as the information on this six-inch map clearly was to a large section of the public, its informa- tion has been allowed to remain unpublished, and now Mr. Stanford has had to step in to supply the deficiency. Taking advantage of his excellent and well-known library map of London, and securing the services of Mr. James B.Jordan, who has had so much experience in work of this character, he has issued the geological information in question in a very convenient form. The map em- braces all the area from Finchleyon the north to Becken- ham on the south, and from Blackheath on the east to Shepherd's Bush on the west. The subdivisions of the superficial deposits are not so numerous as might possibly have been desired on a map of this large scale, and the work shows too evident traces of having been compiled from a variety of different sources, some of the areas having been carefully surveyed on the six-inch scale> while others are only enlargements of the one-inch map. Nevertheless, with all these drawbacks the map furnishes information not to be obtained from any other published source, and it will supply a want that was beginning ta be extensively felt among the ever-growing population of the metropolis. The colours of the map are exceedingly well chosen, and tastefully combined. Until it is superseded by an authoritative Government publication on the same scale, it is sure to have an extensive circulation. 236 NATURE \_7une 27, 1878 NOTES The follo\\ing is a list of the officers of tlie Forty-eighth Annual Meeting of the British Association, which will, as we have intinaated, commence at Dublin on Wednesday, August 14, 1878. President Elect— William Spottiswoode, LL.D., F.R.S. Vice-presidents Elect — The Right Hon. the Lord Mayor of Dublin, the Provost of Trinity College, Dublin, His Grace the Duke of Abercorn, K.G., the Right Hon. the Earl of Ennis killen, D.C.L., F.R.S., the Right Hon. the Earl of Rosse, D.C.L., F.R.S., the Right Hon. Lord O'Hagan, M.R.I.A Prof. G. G. Stokes, D.C.L,, LL.D., Sec.R.S. General Secretaries— Capt. Douglas Gallon, C.B., D.C.L,, F.R.S Philip Lutley Sclater, Ph.D., F.R.S. Assistant General Secre tary — G. Griffith, M.A., Harrow. General Treasurer — Prof. A. W. Williamson, Ph.D., F.R.S. Local Secretaries— Prof R. S. Ball, LL.D., F.R.S., James Gofif, John Norwood LL.D., Prof. G. Sigerson, M.D. Local Treasurer — T. Maxwell Hutton. The following are the presidents of sections : — A. — Mathematical and Physical Science. — President : The Rev, Prof. Salmon, D.D., D.C.L., F.R.S. B.— Chemical Science. —President: Prof. Maxwell Simpson, M.D,, F,R,S, C— Geology.— President : John Evans, D.C.L., F.R.S. D,— Biology.— President : Prof. W. H. Flower, F.R.S. Depart- ment of Zoology and Botany: Prof. W. W. Flower, F.R.S. (president), will preside. Department of Anthropology : Prof, Huxley, Sec.R.S. (vice-president), will preside. Department of Anatomy and Physiology: R. M'=Donuell, M.D., F.R.S. (vice-president), will preside. E. — Geography.— President : Prof. Sir Wyville Thomson, LL.D., F.R.S, L, & E. F.— Economic Science and Statistics, — President : Prof. J. K, Ingram, LL.D. G, — Mechanical Science. — President : Edward Easton, C.E, The first general meeting will be held on Wednesday, August 14, at 8 P.M., when Prof. Allen Thomson, M.D., LL.D., F.R.S.L. & E., will resign the chair, and William Spottiswoode, M,A., LL.D., F.R.S., F.R.A.S., F.R.G.S., president elect, will assume the presidency, and deliver an address. On Thursday evening, August 15, at 8 P.M., a soiree ; on Friday evening, August 16, at 8.30 p.m., a discourse by G, J, Romanes, F.L.S., on Animal Intelligence; on Monday evening, August 19, at 8.30 P.M., a discourse by Prof. Dewar, F.R.S., on Dissociation, or Modern Ideas of Chemical Action; on Tuesday evening, August 20, at 8 p.m., a soiree; on Wednesday, August 21, the concluding general meeting will be held at 2.30 P.M. Excursions to places of interest in the neighbourhood of Dublin will be made on Thiu:?day, August 22. The folloM'ing are the presidents of the numerous sections of the French Association which meets at Paris August 22-29 • — Sections i and 2. Mathematics, Astronomy, Geodesy, and Mechanics, M. Collignon ; 3 and 4. Navigation, Civil and Military Engineering, M. L. Reynaud ; 5. Physics, Prof. A, Cornu ; 6, Chemistry, Prof. Wurtz ; 7. Meteorology and Ter- restrial Physics, M. Herve-Mangon ; 8. Geology, Comte de Saporta; 9. Botany, Prof, H. Baillon ; 10. Zoology and Zoo- techny. Prof, de Quatref ages ; II, Anthropology, Prof, Bertil- lon; 12, Medical Sciences, Prof, Teissier; 13, Agriculture, Baron Thenard ; 14, Geography, M. Maunoir ; 15, Political and Statistical Economy, M, Frederic Passy. The Paris Academy of Sciences has at last succeeded in sending a list of candidates to the Ministry of Public Instruction to fill the place vacated by the death of M, Leverrier, The Academy suggests, by a large majority, the appointment, in the first place, of M, Faye, but M, Faye persists in declining any appointment. In the second place the Academy places the name of M, Loewy, one of the astronomers of the Observatory. M. LoQwy being an Austrian by birth, it cannot be said that the Academy has been influenced by any prejudice of nationality. The other candidates presented by the Council of the Obser- vatory are, in the first line, Capt, Mouchez, and in the second MM, Loewy and Tisserand ex cEquo. It is not yet known what the minister will do. He is at liberty to appoint any other astronomer who has shown himself qualified for the exalted position, as we have announced, M.Mascart has already taken possession of his post at the Observatory as being at the head of the meteorological bureau, but although the principle of sepa- rating astronomy and meteorology has been decreed, they are making at the observatory active preparation to fit up new offices for the meteorological bureau. Both services are to be separated, officially and financially, but are to be lodged in the same building as they were during Leverrier's rule. The formal opening of the Meteorological Pavilion at the Exhibition took place on Monday. The Anniversary Meeting of the Sanitary Institute will be held at the Royal Institution, Albemarle Street, on Wednesday, July 3, at 4 P,M., when an address will be delivered by Mr. Frank T. Buckland, on "The Pollution of Rivers and its Effects upon the Fisheries and the Water Supply of Towns and Villages." The Annual Conversazione of the Members and Friends of the Institute will be held on the same evening at 8 o'clock, at the Gros\'enoT Gallery, New Bond Street. The Autumn Congress and Exhibition of the Instittite will be opened at Stafford on Wednesday, October 2, 1878. The members of the Institute have been invited to the International Congress of Hygiene, under the patronage of the French Government, \\'hich will be Ijeld at Paris during the first ten days in August, 1878. We commend to our readers a movement which has been set on foot for the presentation of a testimonial to Mr. P. Le Neve Foster, the secretary of the Society of Arts, upon the occasion of his completing his twenty- fifth year of service as chief executive officer. When Mr, Foster became its secretary the society numbered only about I, coo members. At the present time it now numbers about 4,000. During the period of Mr. Foster's administration the Society has successfully dealt with many important public questions, including those of elementary and technical education, patent and copyright law reform, inter- national exhibitions, public health, Indian and colonial and many other topics. Upon these, grounds an appeal is made to the members of the Society and the public for their co-operation. An influential committee has been formed, with Lord Hatherley as president. We notice tke death, in Niirnberg, on June 5, of Baron Ern-j. von Bibra, in his seventy-second year. Baron von Bibra pre- sented an interesting instance of a cultured nobleman devoting himself entirely to science and letters, and attaining distinction in both branches — a type of character not altogether uncommon in England, but much more rarely encountered in Germany. After the completion of his university studies at Wiirzburg, he carried out at his castle in Franconia a series of chemical researches which, especially from a physiological point of view, attracted considerable attention. Among these were " Chemical Investigation of Various Purulent Matters " (1842) ; " Chemical Investigations on the Banes and Teeth of Mankind and the Ver- tebrates (1844); "Physiological Action of Phosphorus on the Workmen in Match Factories," "Action of Ether" (1847); " Chemistry of the Liver and Gall " (1849) ; and " Composition of the Blood of the Lower Animals" (1849). In 1850 he undertook an extensive tour through South America. On his return he published analyses of sea-water collected from a variety of points in the Atlantic and Pacific. These were followed in 1853 and 1854, by valuable monographs on the "Composition of the Brain, Spinal Marrow, and Nerves;" June 27, 1878] NATURE ^^'- 237 "Action of Narcotics on the Human System;" and "Contri- butions to the Natural History of Chili ; " and in 1858-60, by rese::rches on cereals and coffee. At this period von Bibra turned hb attention more especially to belles-lettres. The record of his travels in South America was followed by works of fiction, and in a short time he won a prominent place among the German novelists of the day. So fruitful was his pen that no less than fifty-one volumes of novels and tales appeared under his name from 1861-73. Despite this degree of literary activity, the claims of science were not entirely neglected. Papers appeared from him at intervals on various South American mineral?, on the chemical composition of various German geological forma- tions, on the properties of aluminium, on a bismuth tin-lead alloy nearly as fusible as Rose's metal, on methods for regaining silver from the solutions of the cyanid, &c. Of more im- portance were two chemico-archseological monographs "On the Bronze and Copper Alloys of Antiquity" (1869), and " Ancient Iron and Silver Work" (1873). A paper " On the Restoration of Ancient Manuscripts and Paintings " which appeared during the present year, was lately alluded to in these columns. Baron von Bibra was a corresponding member of the Vienna Academy, and several other German academies. The State Museum of Sweden has suffered a severe loss through the death of Prof. C. Stil, which occurred on the 14th inst., after a few days' illness; Prof. Stil was only 45 years of age. He was keeper of the Entomological Department of the Museum, to the maintenance of which he devoted an unusual activity and diligence. He is widely known in the scientific world as the author of many important papers on hemiptera and orthoptera, to the systematising of which orders he chiefly con- tributed. He has been snatched away before his time from other works unfinished and from a large circle of friends who deeply deplore the decease of the amiable and faithful man. With the formation of international exhibitions like that now attracting the world's notice at Paris, there are placed on record, in the form of catalogues, lists of all, or nearly all, the contents of an immense building. These contents are, as it is intended they should be, of a very varied character. The catalogues themselves being the productions of different sections or depart- ments and of widely different nations, consequently we might expect some difference of character in the preparation of these " Guides." Too often a bulky book is produced which is nothing more than a mere list of exhibitors' names and addresses, of no use to the visitor while in the exhibition, and of still less use for reference after. Thus, for instance, opening promis- cuously the catalogue of the British Section of the present exhi- bition, our eye rests on the name of a well-known firm of manu- facturing chemists, but all the information we obtain about their exhibits is " Pure Chemicals and Pharmaceutical Products," The Australian colonies have hitherto distinguished themselves in producing full and descriptive catalogues which have been worth a place in the library not only as records of each great show, but as books of reference on the products of the Colonies. We are glad to find that our Indian exhibits are being treated in a somewhat similar way, for we have before us a "Cata- logue of the Raw Products of Southern India Collected and Forw arded (under orders of the Government of Madras) to the Paris International Exhibition of 1878." This Catalogue has been prepared by Dr. G. Bidie, the Superintendent cf the Government Central Museum at Madras, and comprises sub- stances used as drugs, for food, and in manufactures. Forest products, such as woods, are excluded from this catalogue for the reason that their collection and exhibition has been made a specialty by the Forest Department, a catalogue of which has been drawn up under the title of a " Catalogue of Specimens of Timber, Bamboos, Canes, and other Forest Produce from the Government Forests in the Provinces under the Government of India and the Presidencies of Madras and Bombay." Return- ing to the first-named catalogue we have an exceedingly well drawn up handbook of 136 pages -divided into three great divisions of drugs, food substances, and sub- stances used in manufactures, each being lettered in red on the margin for easy reference. These primary divisions are subdivided into products of the vegetable, animal, .and mineral kingdoms, and, in the case^of the drugs, again subdivided into such as are officinal in the Pharmacopoeia of India, those not officinal, but described in the Pharmacopoeia, and those not included in the Pharmacopoeia. Again, amongst foods we have agricultural produce, such as cereals, pulses, &c., fruits and seeds, substances used in the preparation of drinks, &c., and so on through each great division. The genera of plants are arranged under each natural order, and, being printed in black letters, are very easily found. After the Latin name follows the English, French, German, and other vernaculars. The plan of the book is, in short, founded on Bridwood's "Economic Pro- ducts of Bombay," with many improvements. From the cata- logue of specimens of timber, bamboos, &c., we find that as many as 650 different specimens of woods have been sent from India to the Exhibition, the total number of specimens of woods and other products of trees amounting to 1,055, ^vhich, at the close of the Exhibition, are to be presented, by order of the Indian Government, to the French National School of Forestry at Nancy, "where," as we read, "for ten years past a large proportion of the forest officers of India have^ received their professional education." M. DE Lesseps has inaugurated at the Paris Exhibition a series of lectures, which will be given on Saturdays at two o'clock in the Egyptian House erected by the Suez Company and the Egyptian Government. This house has been built from designs by Mariette-Bey, and professes to represent the mansion of a noble Egyptian at the end of the thirteenth dynasty, before Abraham was born. It consists of a court and a number of rooms. In one of the largest has been placed a model of the Suez Canal and a bird's-eye view of the delta and the Isthmus. M. de Lesseps explained the great work of boring the canal, the actual state of the lands of the Company and the influence of the salaries paid to natives during the execution of the works. A second lecture by M. de Lesseps was delivered in the second hall, • where has been hung an immense map of Africa as at present known. Relics of Livingstone, his books, instruments, cap, &c., ha\'e been disposed in the room as well as objects connected with the natural history, industry, and trade of the lake region. M. de Lesseps lectured on the necessity of supporting the Interna- tional Society for the Civilisation of Africa, and on the results accomplished by the Egyptian Government in taking possession of the banks of the Nile from 31° to 1° N. lat. A CONGRESS of Demography will be held at the Trocadero Palace from July 5 to 9 to discuss the following topics : — Census of population, registers of population, organisation of statistics, registration of births and deaths, publication of periodical demographical results relating to large cities, emigration, &c. A Congress of Anthropological Science well be held in the same place from July 15 to 17. The programme consists of old things adorned with new names, such as ethnodicee, ethno- gepie, &c. Let not those of our mathematical readers who are rather shaky in their French be misled by a letter in Saturday's Times from the editor of the jfournal des GJomHres, inviting English geomltres to a conference to be held in Paris on July 8 and 9. The context seems to show that the French word geomitris has really its original Greek signification of "land-measiurer," and corresponds more nearly to English "surveyor" than anything 238 NATURE \t \yune 27, 1878 else, the exact French term being, we believe, Arpenteur- giotnetre. As the Paris Daily News correspondent showed the other day, even good French scholars may make themselves ludicrous to a Frenchman by translating words literally into their corresponding French forms, such as physicien and chimiste, which, we need hardly say, mean not physician and pharma- ceutical chemist, but physicist and scientific chemist. A GENERAL meeting of the Mineralogical Society of Great Britain and Ireland will be held at the Meteorological Office, 116, Victoria Street, on July 4, at 8 p.m., when the following papers will be read: — "On a New Manganesian Garnet," by Prof. M. F. Heddle. ; "On Cotterite, a New Variety of Quartz," by Prof. Harkness ; " On Youngite," by Messrs. David Stewart and J. J. Hood, communicated by Mr. J. B. Hannay ; "Notes on Cornish Minerals," by Mr. J. H. Collins. There is every prospect at present of the early commence- ment of another of the gigantic engineering enterprises charac- teristic of our century. The last steamer from Panama brings news of the ratification of the contract between the Government of Columbia and the International Committee for the Construc- tion of a Canal across the Isthmus of Darien. Among the conditions we notice the clause declaring the future canal to stand open to the commerce of the entire world, and to be entirely neutral. Another condition is the completion of the work before 1895, ^^t we fear that only pronounced optimists will look forward to the fulfilment of this clause. The Canal Company receives a grant of land including stretches 200 yards wide on each side of the canal, and over 1,000,000 acres in addition, to be chosen at will. It has besides the free use of all building materials on the isthmus, so that no complaint can be made of a lack of readiness on the part of Columbia to further the undertaking, M. Bardoux has opened at the Palais du Champ de Mars the Exhibition connected with Public Instruction, The minister said in his address that, owing to the recent progress of France, that country was now inferior to no other European nation as regards popular education. The results of the last conscription are highly satisfactory in this respect. Out of 294,382 men admitted into the ranks of the French army in 1877, only 4,992 were unable to read or write, 2,620 had taken their preliminary degrees in letters or sciences, 234,279 kn.w the "three R's," 36,325 could only read and write, and 5,856 could only read. Elementary schools have been established in the various regiments of the French army for years, but the attendance, which had been very limited, is now almost universal. Not less than 305,989 soldiers were pupils of regimental schools in 1877 ; out of these, 255,380 fol- lowed the course of elementary instruction, 36,981 the secondary course, and 4,682 the course of superior instruction. The army has been turned into a machine for promoting elementary know- ledge. In 1877 not less than 33,337 soldiers learned to read, 24,483 to write, and 111,303 were taught arithmetic. Under guidance of their officers, 200 soldiers firom the garrisons of Paris visit the Exhibition daily. The Emperor of Germany has named Prof, von Briicke, of Vienna, and the mathematician, C. Hermite, of Paris, as knights of the Order of Merit for Science and Art. The well-known physicist, Prof. Clausius, of Bonn, has been elected a member of the Swedish Academy of Sciences, M. G. A. Six has lately Avritten a history of the progress of botany in Holland, a work for which this little kingdom has certainly furnished rich material during the past two centuries. An interesting fact for agriculturists is communicated by Herr Rudolf Mayerhoffer, of Prague, the editor of the agricultural serial, Dcr BicnenvatLr aus Bohmen. It appears thr.t a German colonist upon the Island of Java has successfully tried the culti- vation of the native bee, Apis dorsata, which hitherto has been valued by the natives only for the sake of the larva;. Herr Mayerhoffer even expresses the hope that it will be possible to acclimatise the Javanese bee in Europe. On July I Prof, Victor Carus will bring out the first number of a new serial entitled Zoologiscker Anzeiger, which will form a sort of zoological record in monthly instalments, and, to a certain extent, will be the continuation of Carus and Engel- mann's invaluable " Bibliotheca Zoologica." Engelmannof Leipzig is the publisher. The new serial will contain communications r^jarding museums, institutions, and private collections, notes on zoological and biological subjects, besides a quantity of gene- rally interesting scientific matter. The Japan Times understands that for the Hong-Kong "afforestation" scheme considerable quantities of seed have lately been forwarded thither at the request of the authorities. As much as will furnish a quarter of a million trees has been sent, the varieties being the sugi, kinoki, and tsitbaki (the wild, single-flowered camellia). Prof. Frus, of Christiania, who has been engaged for years in the preparation of a complete dictionary of the Lapp language^ has nearly brought his work to a conclusion. This language is richer than most of the northern tongues, the first eleven letters of the alphabet embracing not less than l2,oco words. The Harvey Tercentenary Memorial Fund is so far advanced that it has been resolved to take steps to select a sculptor to whom the execution of the memorial statue should be intrusted. Of 1,680/. subscribed, 1,228/. are in hand. A Manatee, caught at the mouth of the Essequibo River, British Guiana, is now on view at the Westminster Aquarium. The poor " whale " has gone the way of its predecessor. M. A. CossA has recently communicated to the Acadcmia dei Lincei the results of extensive litho-chemical investigations on the Island Volcano, north of Sicily. He has succeeded in finding here considerable quantities of the sulphates of the rare metals lithium, thallium, caesium, and rubidium, apparently in the form of alums. The metals appear to have been present in the rocks surrounding the crater, as silicates, and the latter have been decomposed by the acid vapours mounting from the interior of the volcano. Hitherto the mineral poUux scattered over the Island of Elba has been the most abundant source of cesium and rubidium. The additions to the Zoological Society's Gardens during the past week include a Pig-Tailed Monkey {Macacus net}testnnus) from Java, a Scarlet Ibis {!bis rubra), a Red-Billed Tree Duck (Dendrocygna aulutnnalis) from South America, presented by Mr. R. M. Hyde; a Green Monkey {Cercopithecus callitrichus\ from West Africa, presented by Mr. Samuel Curtis ; an Indian Gazelle {Gazdla bennetti) from India, presented by Miss Statter; two Prairie Marmosets {Cynamys ludovicianus) from North America, presented by M. J. N. Comely ; three Common Cormorants (Pkalacrocorax carbo), British Isles, presented re- spectively by Mr. Edward Banks and Mr. W. Thompson ; two Cereopsis Geese {Cercopsis novce-hollandia), two Australian Shel- drakes {Tadorna taniatus) from Australia, a Yellow-Billed Sheathbill {Chiornis alba) from Antarctic America, purchased; two Mantchurian Crossoptilons {Crossoptilon ma/tU/iuriaim) from China, received in exchange ; two Argus Pheasants (Arpis giganteus), four Summer Ducks {Aix sponsa), four Chiloe Widgeons {Mareca ckiloensis), three Australian Wild Ducks {Anas supariliosa), bred in the Gardens. Jti7ie 2'], 1878] NATURE 239 ON THE PHYSICAL ACTION OF THE MICROPHONE ' IN the paper read on May 9 before the Royal Society I gave a general outline of the discoveries I had made, the materials used, and the forms of microphone employed in demonstrating important points. I have made a great number of microphones each for some special purpose, varying in form, mechanical arrangement, and materials. It would require too much time to describe even a few of them, and as I am anxious in this paper to confine myself to general considerations, I will take it for granted that some of the forms of instrument and the results produced are already known. The problem which the microphone resolves is this — to intro- duce into an electrical circuit an electrical resistance, which resist- ance shall vary in exact accord with sonorous vibrations so as to produce an undulatory current of electricity from a constant source, whose wave-length, height, and form shall be an exact re- presentation of the sonorous waves. In the microphone we have an electric conducting material susceptible of being influenced by sonorous vibrations, and thus we have the first step of the problem. The second step is one of the highest importance : it is essential that the electrical current flowing be thrown into waves of determinate form by the sole action of the sonorous vibra- tions. I resolved this by the discovery that when an electric conducting matter is in a divided state, either in the form of powder, filings, or siu-faces, and is put under a certain slight pres- sure, far less than that which would produce cohesion and more than would allow it to be separated by sonorous vibrations, the following state of things occurred : — The molecules at these sur- faces being in a comparatively free state, although electrically joined, do of themselves so arrange their form, their number in contact, ©r their pressure (by increased size or orbit of revolu- tion), that the increase and decrease^of electricalVesistance of the circuit is altered in a very remarkable manner, so much so as to be almost fabulous. The problem being resolved it is only necessary to observe cer- tain general considerations to produce an endless variety of microphones each having a special range of resistance. The tramp of a fly or the cry of an insect requires little range, but great sensitiveness, and two sxirfaces therefore of chosen materials under a very slight pressiure, such as the mere weight of a small superposed conductor, suffice ; but it would be un- suitable for a man's voice, as the vibrations \\ould be too power- ful, and would, in fact, go so far beyond the legitimate range, that interruptions of contact amounting to the well-known "make and break " would be produced. A man's voice requires four surfaces of pine charcoal, as is described in my paper to the Royal Society, six of willow charcoal, eight of boxwood, and ten of gas carbon. The efi"ects are, however, far superior with the four of pine than with either the ten of gas carbon or any other material as yet used. It should be noted that pine wood is the best resonant material we possess ; and it preserves its structure and quality when converted into the peculiar charcoal I have discovered and described. It is not only necessary to vary the number of surfaces and materials in accordance with the range and power of the vibra- tions, but these siurfaces and materials must be put under more or less pressure in accordance with the force of the sonorous vibrations. Thus, for a man's voice the surfaces must be under a far greater pressure than for the movements of insects ; still the range of useful effect is very great, as the boxes which I have specially arranged for a man's voice are still sensitive to the tick of a watch. In all cases it should be so arranged that a perfect undulatory current is obtained from the sonorous vibrations of a certain range. Thus, when speaking to a microphone transmitter of human speech, a galvanometer should be placed in the circuit, and, while speaking, the needle should not be deflected, as the waves of -f and - electricity are equal, and are too rapid to disturb the needle, which can only indicate a general weakening or strengthening of the current. If the pressure on the mate- rials is not sufficient, we shall have a constant succession of interruptions of contact, and the galvonometer-needle will indi- cate the fact. If the presssure on the materials is gradually increased, the tones will be loud but wanting in distinctness, the galvanometer indicating interruptions ; as the pressure is still ■• By Prof. Hughes. Cca.municated to the Physical Society, June 8, 1878. increased, the tone becomes clearer, and the galvanometer will be stationary when a maximum of loudness and clearness is attained. If the pressure be further increased, the sounds become weaker, though very clear, and, as the pressure is still further augmented, the sounds die out (as if the speaker was talking and walking away at the same time) until a point is arrived at where there is complete silence. When the microphone is fixed to a resonant board the lower contact should be fixed to this board, so that the sonorous vibrations act directly on it. The upper contact, where the pressure is applied, should be as free as possible from the influence of the vibrations, except those .directly transmitted to it by the surfaces underneath; it (the upper surface) should have its inertia supplemented by that of a balanced weight. This inertia I find necessary to keep the contact unbroken by powerful vibrations. No spring can supply the required inertia, but an adjustable spring may be used to ensvure that the com- paratively heavy lever shall duly press on the contacts. The superposed surfaces in contact may be screwed down by an insulated screw passing through them all, thus doing away with the lever and spring; but this arrangement is far more difficult to adjust, and the expansion by heat of the screw causes a varying pressure. It is exceedingly simple, however, easily made, and illustrates the theoretical conditions better than the balanced lever I have adopted in practice. In order to study the theoretical considerations, and that with the most simple form of microphone, freed from aU surrounding mecha- nisms, let us take a flat piece of charcoal two millims, thick and one centim. square, and, after making electrical contact by means of a copper wire on the lower surface, glue that to a small resonant board, or, better for the purpose of observation, to a block or cube of wood ten centims. square. Upon this superpose one or more similar blocks, the upper surface in communication with a wire, the lower resting flat, or as nearly so as possible, on the lower block. The required pressure is put on the upper block, and while in this state the two may be fastened together with glue at the sides, or, better, by an insulated screw. The pressure can then be removed, as the screw or glue equally preserves the force. Let the lower piece be called A and the upper B : when we put this block or board under sonorous vibrations, we cannot suppose an undulatory movement of the actual wave-length in such a mass, that is a length comparable with the real wave-length of the sonorous wave which may be several feet. Now we cannot suppose a wave of any length without admitting that the force must be transmitted from molecule to molecule throughout the entire length : thus any portion of a wave, of which this block represents a fraction, must be in molecular activity. The lower portion of the charcoal A, being part of the block itself, has this molecular action throughout, transmitting it also to the upper block. How is it that the molecular action at the surfaces A and B should so vary the conductivity or electrical resistance as to throw it into waves in the exact form of the sonorous vibrations ? It cannot be because it throws up the upper portion, making an intermittent current, because the upper portion is fastened to the lower, and the galvanometer does not indicate any interruption of current what- ever. It cannot be because the molecules arrange themselves in stratified lines, becoming more or less conductive, as then sur- faces would not be required— that is, we should not require discontinuity between the blocks A and B ; nor would the upper surface be thrown up if the pressure be removed, as sand is on a vibrating glass. The throwing up of this upper piece B when pressure is removed proves that a blow, pressure, or upheaval of the lower portion takes place— that this takes place there cannot be any doubt, as the surface, considered alone (having no depth), could not bodily quit its mass. In fact, there must have been a movement to a certain depth ; and I am inclmed to believe, from numerous experiments, that the whole block mcreases and diminishes in size at all points, in the centre as well as the surface, exactly in accordance with the form of the sonorous wave Confining our attention, however, to the pomts A and B, how can this increased molecular size or form produce a change in the electrical waves ? This may happen in two ways : first,%y increased pressure on the upper surface, due to its en- lar 2IO 240 + 10-78 + 0-73 240 270 + 27-76 + 5*45 ,, 270 300 + 37*35 + 8-33 >> 300 333 + 35*33 + 7*29 )> 330 363 + 16-62 + 2-41 If we now turn to declination-ranges we shall find that there are greater oscillations or sub-periods in the value of these ranges during times of maximum than during times of minimum sun-spots. But on the other hand the increased value of such oscillations is by no means so striking as in the case of sun-spots. Mr. Broun has already made the remark that while there is an increase in the whole declination-range during times of maximimi sun-spots, yet this increase is not so marked as in the case of the spots themselve?, inasmuch as we have a considerable declina- tion-range when there are no spots on the sun. From what has now been said it would seem that a similar remark applies to the oscillations or sub-periods of declination-range, which, while increasing from times of minimum to times of maximum sun- spots, do not yet increase so strikingly as the oscillations or sub- periods of the spots themselves. If we now treat the inequalities of magnetic declination that appear to depend on the two most available planetary configura- tions in the manner in which we have just treated sun-spot inequalities, we might expect the observed magnetic inequalities corresponding to times of maximum sun-spots to be greater than the mean inequalities, but not to the same extent as in the case of sun-spots. That this is the case will be seen from the following table, in which observed declination-range, planetary inequalities for periods of maximum sun-spots are compared with the corre- sponding mean inequalities : — Period of Mercury. , Observed. Mean. Between 0 and 30 +11-48 -t- 10-42 33 ,, 60 -f 3-62 -f 7-25 60 „ 90 - 3*50 - 2-25 90 M 120 - 6-91 - 3-25 ,, 120 ,, 150 - 9-13 - 8-16 150 „ 180 - 12-37 - 11-67 ,, 180 ,, 210 - 13-72 - 12-12 ,, 210 ,, 240 - 10-44 - 8-68 240 ,, 270 - 2-45 - 2-62 270 „ 300 -t- 7-73 -+- 4*10 300 „ 330 + 15-14 + 9*26 330 „ 360 + I6-20 -f 11-27 Mercury and Jupiter together. „ Observed. Mean. Between o and 30 -1-11-87 -f 11 -61 30 „ 60 -f 2-56 -f 8-07 60 „ 90 - 4-26 -t- 2-75 90 „ 120 - 8-72 - 2-45 120 „ 150 - 13-85 - 7-93 M 150 ,, 180 - 16-24 - 11-97 M 180 ,, 210 - 13-44 - 11-80 „ 210 ,, 240 - 8-32 - 8-71 ,, 240 ,, 270 + 0-51 - 3-11 270 ,, 300 + 11-39 -t- 3-44 300 „ 330 -J- 16-91 -1- 8-74 „ 330 „ 360 -1- 17*06 -1-11-89 It thus appears that in the case of the magnetic decKnation periods there is (as in those of sun-spots) an exaltation of the observed over the mean values during times of maximum sun- spot frequency, but this exaltation is not so marked as in the case of sun-spots. Now, without pretending to know in what way the sun influences the magnetism of the earth, we may imagine that the increased values not only of the average declina- tion-range but also of the sub-periods of these during times of maximum sun-spots may be due to one of two causes, or to both of these together. Thus we may imagine that the sun has an increased magnetic influence during such periods, or we may imagine that there is an increase in the magnetic susceptibility of the earth ; or, finally, we may imagine that both of these causes operate together. The author cannot help thinking that we have some evidence of an increase of the magnetic suscepti- bility of the earth on such occasions derived from two facts dis- covered by Mr. Broun. The one is that the magnetic influence of the moon on the earth shows traces of following the solar period, this influence being greater during times of maximum than during times of minimum sun-spots. The other is that at Trevandrum the lunar magnetic influence, without changing its type, exhibits an increase of value when the sun is above the horizon at that place, as if on such occasions there were an increase of susceptibility to the lunar influence. These, how- ever, are points which can only be determined by a further discussion of observations. Geological Society, May 22. — Henry Clifton Sorby, F.R.S., president, in the chair. — ^John Collins was elected a Fellow of the Societ}-. — The following communications were read : — On the serpentine and associated igneous rocks of the Ayrshire coast, by Prof. T. G. Bonney, M.A. — In a paper published in the Quarterly Journal of the Geological Society, vol. xxii. p. 513, Mr. J. Geikie states that the rocks of this district are of sedi- mentary origin, a felspar-porphyry being the '^maximum stage of metamorphosis exhibited by the felspathic rocks," and the diorite, hypersthenite, and serpentine being all the result of metamorphism of bedded rocks. This view is also asserted in the catalogue of the rocks collected by the Geological Survey of Scotland. The author had seen specimens of rocks_ from this district which so closely resembled some from the Lizard, that he visited the Ayrshire coast in the summer of 1877. The author is of opinion that the principal conclusions of the paper referred to above are not warranted by either stratigraphical or lithological evidence. He considers it probable that the " felspar-porphyry," like so much of that in Scotland, is of old red sandstone age, and that the serpentine is of later date. 244 NATURE \_yune 27, 1878 but palaeozoic. — On the metamorphic and overlyiag rocks in the neighbourhood of Loch Maree, Ross-shire, by Henry Hicks, M.D., F.G.S. The rocks in the neighbourhood of Loch Maree have been described by various authors, but chiefly and most recently in papers communicated to the Geological Society by Prof. Nicol, of Aberdeen, and by Sir R. Murchison and Prof. Geikie, of Edinburgh. In the present communication the author endeavours to show, from results obtained by him re- cently by a careful examination of a section extending from Loch Maree to Ben Fyn, near Auchnasheen, that the interpre- tations previously given are in some important points incorrect, and that this has been to a great extent the cause of such very diverse opinions. — On the triassic rocks of Normandy and their environments, byW. A. E. Ussher, Esq., F.G.S. — On foyaite, an elseolitic syenite occurring in Portugal, by C. P. Sheibner, Ph.D., F.G.S. Communicated by Prof. T. M'Kenny Hughes, M.A., F.G.S. Zoological Society, June 4. — Prof. Flower, F.R.S., vice- president, in the chair. — Mr. Sclater exhibited a young specimen of Temminck's Manis {Manis tenwiincki), and read a note de- scribing habits of this animal in captivity by Mr. F. Holm- wood, Assistant Political Agent at Zanzibar. — Mr. Sclater also called attention to the extraordinary mimicry of the true rectrices by the elongated upper tail coverts in Ciconia maguari and C. episcopus, as observable in the living examples of these birds in the Society's Gardens. — Mr. Edward R. Alston exhibited, on behalf of Dr. Elliott Coues, two specimens of Synaptomys cooperi. To this species — the type of Synaptomys, proposed in 1867 by Prof. Baird as a sub-genus of Myodes — full generic rank was accorded by Dr. Coues in 1874. The present specimens were, so far as was known, the first typical specimens sent to Europe. — Prof. Huxley, F.R.S., read a memoir on the cray- fishes, in which he gave a review of the various generic divisions of this group of podophthalmous Crustacea, and pointed out how remarkably these divisions corresponded with their geographical distribution. —Prof. W. H. Flower, F.R.S., exhibited the skull of a two- horned rhinoceros from Tipperah, and read a note on the pecu- liarities of its structure. — A communication was read from Messrs. Godman, Salvin, and Druce, containing a catalogue of the lepidoptera collected by Mr. S. N. Walter in the Island of Billiton. — Messrs. Godman and Salvin also read a list of the but- terflies collected in Eastern New Guinea'and some neighbouring islands by Dr. Comrie, during the voyage of H.M.S. Basilisk. — Mr. A. G. Butler, F.Z.S., read a paper containing the descrip- tion of a new si^ecies of the orthopterous genus Phylloptera, from Madagascar, which he proposed to name Phylloptera segonoides. — Messrs. Sclater and Salvin read a report on the col- lection of birds made during the voyage of H.M.S. Challenger. The present communication, forming the eleventh of the series, contained a description of the Steganopodes and of the Im- pennes. Of the first group the collection contained thirty-three specimens belonging to eight species ; of the second, thirty seven specimens belonging to six species. — Prof. E. Ray Lankester read a paper in which he gave an accomit of the structiu-e of the hearts of Ceratodus, Protopterus, and Chimccra, with an account of certain undescribed pocket-valves in the conus arteriosus of Ceratodus and of Protopterus. Institution of Civil Engineers, May 28. — Mr. John Frederic Bateman, F.R.S., president, in the chair. — The dis- cussion on Mr. T. C. Clarke's paper on the design of iron railway bridges of very large spans, was continued throughout the evening. Rome R. Accademia dei Lincei, April 7, 1878. — The following among other papers were read : — Human skeleton in a cavern of the Arena Candida, near Finalmarina, by M. de Sanctis. — PalKontological notes on a large fossil humerus of a bear and other bones of a stag, from a cave near Poggio Mojano, by M. Ponzi. — New researches on Fourier's series, by M. Ascoli. — On carbotialdina and some other sulphurised compounds, by M. Guareschi. — On some derivatives of tetrachlorated ethers, by M. Paterno. — On new derivatives of santonines, by M. Valenti. — On secular variations of the magnetic declination at Rome, by M. Kella. — Map of the planet Mars, by M. Schiaparelli. — On Hofmannite, by M. Bechi. Paris Academy of Sciences, June 10. — M. Fizeau in the chair. — '^^.;f9llpwing among other papers, were read : — On the results furnished by chronometers having springs with theoretical terminal curves, at the prize competition of 1877, at Neuchatel Observatory, by M. Phillips. . Of the 220 chronometers sent in 186 had springs with theoretical curves. M. Granjean's occu- pied the first place for their remarkable accuracy. — On the gemmiparous and fissiparous reproduction of Noctilucse {Noc- tUuca miliaris, Suriray), by M. Robin. The processes are detailed, and several new facts communicated. — On the con- servation of old types of ships, by Admiral Paris. The author's project is to reproduce figures of ancient ships from all parts of the world ; he has written to the naval authorities in many countries to send drawings, with explanatory data. Some of his plates are exhibited in the Champ de Mars. — Functions of leaves in the phenomenon of gaseous exchanges between plants and the atmosphere ; rdleoi stomates in the functions of leaves, by M. Merget. His conclusion, from experiments, is thus stated : — In aerial and aquatic-aerial plants, oxygen, nitrogen, and carbonic acid are exchanged normally between the interior and the exte- rior atmosphere by way of the stomatic orifices. These exchanges may be produced by simple diffusion ; they are pro- moted by all causes capable of producing a rupture of equilibrium between the two atmospheres, and in the double gaseous circu- lation which follows, the two movements of entrance and exit are performed with equal facility,— Observation of the transit of Mercury at Paita, by Admiral Serres. The conditions were highly favourable, and 600 daguerrotypes were obtained. Each officer made an independent report. — Researches on the siib- nitrate of bismuth, by M. Riche. The mechanism of the action of this substance in the system is controverted. It is important that the druggist should supply for it always the same product, and that the sub-nitrate be exclusively prepared with water slightly calcareous according to the formula of Codex. Every product should be rejected which contains less than 12 to 13 per cent, of nitric acid. — On the physiological role of hypophos- phites, by MM. Paquetin and Soly. They are shown to be not reconstituents but diuretics. — On the colouring matter of wines, by M. Gautier, Each stock produces one or several special colouring matters, and the principles of these substances together form a family of similar but not identical substances of the aromatic series, having the r6le of acids, pai-tly combined in the wines under the form of ferrous salt, [and apparently resulting from oxidation of the corresponding tannins. He describes the colouring matter of two stocks. CONTENTS p;,GB Henfrey's Botany. By Alfred W. Bennett, F.L.S 217 Paykn's Industrial Chemistry 218 Our Book Shelf : — " Annual Report of the Superintendent of Government Farms." R. Warington 219 Letters to the Editor :— The Size of the Indian Tiger. — Sir J. Fayrer, F.R.S. . , . 219 Zoological Geography. — Searles V. Wood, Jun 220 Time and Longitude. — Rev. S. J. Whitmee 220 New Lunar Crater. — Edward Greenhow 220 Opening of Museums on Sundays. — Prof. W. H. Corfield, Chairman of the Committee of the Sunday Society 220 Ophrys muscifera. — Hermann MOller 221 The Jura. — Marshall Hall 221 The Transit OF Venus Photographs. By Capt. Tupman ... 221 The Norwegi.\n North Atl.-vntic Expedition 222 Physical Science for Artists, VI. By J. Norman Lockyer, F.R.S •• 22^ An Eclipse Spectroscope. By J. Norman Lockyer, F.R.S. {With Illustration) 224 Our Astronomical Column : — Nearest Approximations of Small Planets to the Earth's Orbit . . 225 Measures of Double Stars 225 The Binary Star a Centauri . ' 225 Biological Notes : — Decorative Colouring in Freshwater Fleas 226 How Lepidoptera Escape from their Cocoons '(If^ti/i Illi/stra- >■ tion) .?'....*■. 226 Fear of Snakes in Primates 227 The Fertilisation of Eggs of the Lamprey 227 Geographical Notes 227 Real Brown Bread. By Prof. A. H. Church {With Ilhistration) . 229 The Land of Bolivar and its Products {With Illustrations) . . 230 The Fisheries of British Nosth America, II. By Dr. William B. Carpenter, F.R.S 232 The Geology of London 235 Notes 236 On the Physical Action of the Microphone. By Prof. Hughes 239 Laboratory Notes. By Prof. John G. McKkndrick 240 Volcanic Phenomena AND Earthquakes during ^877 241 University and Educational Intelligence 241 Scientific Serials 242 Socistibs and Academibs . . .' 242 NA TURE 245 THURSDAY, JULY 4, 1878 THE EPOCH OF THE MAMMOTH The Epoch of the Mammoth. By G. James C. Southwell, A.M., LL.D. 8vo. (London : Trubner, 1878.)] BOOKS may be divided into three classes from the point of view offered by criticism, and apart from all considerations of style. There are carefully-written books, the natural fruit of much thought and labour by men who have special knowledge of their subject and who spare no pains to avoid using faulty materials which after- wards may have to be removed, as is generally the case, with much trouble and annoyance. The second class consists of books written without care and very generally the outcome of ignorance or vanity, full of errors, and worse than useless; and lastly, there are some books containing much useful information, but so grouped around views which are utterly wrong that they are worthless for any purpose in which exact knowledge is required. In this class very generally the true is so mingled with the false that it requires the eye of an expert to tell the one from the other. With the first and second of these classes it is easy for a reviewer to deal. It is his duty to welcome the first, not without pointing out (if he can, and we know from experience that very fre- quently he cannot) the mistakes inseparable from all books, just as he is bound to rebuke sternly the second, and to warn the reader that he is on dangerous ground. It is, however, hard to do justice to the third ; for while the information may be useful per se, in its position in the book it may be mischievous because it is worked into a wrong hypothesis, thus fulfilling Lord Palmerston's definition of dirt as " matter in the wrong place." The work before us falls into the third class. Its author seems to have skimmed most of the current litera- ture of the day. more especially reviews, and out of the vast array of facts at his command has picked out those suitable to his views on the recent origin of man. Many of his facts are true, but they are so grouped as to lead the reader to a wrong conclusion. Many of his asserted facts are untrue. The work is a sequel to "The Recent Origin of Man," reviewed in this journal, and is to a large extent an answer to the crjticism which it tfien provoked. We regret that the author has not profited by his experience and that he should have expended so much trouble in attempting to prove a negative which in the nature of things cannot be proved. The author's aim is to show that man has not appeared on the earth more than six or ten thousand years. He starts from the historical basis offered by the Bible, and in support of chronologfy ingrafted on the Holy Writ by the unfortunate ingenuity of Archbishop Usher, and in defence of the high civilisation of primeval man, he seizes some of the scraps of history flung out in the struggle between various Babylonian and Egyptian scholars. He adds to these his own views of the discoveries at Hissarlik and Mycsene, and the recent results of explora- tion in Etruscan tombs and dwellings in Italy, ultimately Vol. xyiii. — No. 453 arriving at the conclusion that man is not older in the Mediterranean area than ten thousand years. To all this the obvious answer suggests itself, that history can tell us nothing as to the antiquity of the human race, because written characters, essential to history, are the result of a high civilisation. How long it took mankind to work out through picture writing a record of the past is an idle question, since we have no data bearing on the point ; but we cannot believe that the art of writing was elaborated in a short time. "Fortes vixere ante Agamemnona" whose names we know not. To attempt to circumscribe the antiquity of man within the limits of history appears to us as idle and barren an attempt as could possibly be undertaken. It would be as reasonable to seek figs growing on thistles as to look for any proof of the recent origin of man in the written record. These facts are so obvious in the present con- dition of knowledge, that we should not bring them before our readers were they not utterly ignored by the author of this work, as well as by some of his critics. Our author having established to his own satisfaction the recent origin of man in the Mediterranean countries, enters into the question of the unity of the human race. The pre-Christian cross, either in the form of the handle cross of the Mediterranean districts or the Swastika of the Buddhists, was widely spread among ancient peoples^ The tradition of a deluge is almost universal. That of a terrestrial paradise is widely spread : we read of the gardens of Alcinous and Laertes, of the Asgard of the Scandinavians, and of sundry other gardens mentioned in various writers Indian, Chinese, and Arabian. Then we have Megalithic monuments scattered over widely- separated countries, and the habit of distorting the human skull, and of scalping. The range, also, of the boomerang, pointed out by Gen. Lane Fox, the custom of depositing flint implements in graves, and of worship- ping phalli and serpents, are taken to " prove the unity of the race, almost without any other argument on the subject." Then the author proceeds to his application, " If the human race is one, the Egyptian, the Hindoo, the Baby- lonian, and the palaeolithic tribes of the Somme Valley were one ; and if Kephren and Cheops were near of kin to the fossil man of Mentone or the savage who owned the Neanderthal skull, and if, moreover, the antiquity of man in Babylonia does not go farther back than some ten thousand years, then the men of the French and English river gravels cannot be more than ten thousand years old. The reverse would only be possible on the hypothesis that the Egyptians were the descendants of the men of the Somme Valley. But this is excluded by the fact that the Egyptians appear at once as a civilised race; and, as we have stated, there are no earlier remains of any kind in Egypt" (p. 21). We give this as an example of the style of reasoning. So far as we know, nobody, not even the author, has ventured to assert that the two Egyptian kings above mentioned "were near of kin" to the so-called fossil man of Mentone, or stood in any near relationship to- any of the ancient inhabitants of Europe. The argument is to us wholly unintelligible. Why should the Egyptians be descended from the men of the Somme Valley any 246 NATURE {July d,, 1878 more than the latter from the Egyptians ? The civilisa- tion of Egypt throws about as much light upon the barbarism of the palaeolithic age as that does upon the civilisation of Egypt. The author has taken great pains to break down the archaeological classification by the trite argument that bronze, iron, and stone have been very frequently found together in various parts of Europe. We suppose that no modern archasologist has disputed the fact. Dr. John Evans holds that they shade off into one another like the prismatic colours of a rainbow, Dr. Keller and Mr. Lee? his able translator, give numerous examples from the pile dwellings of Switzerland, and other places, of the association of implements composed of these materials. This association, however, has nothing to do with the question as to whether the archaeological classification is correct. The conclusion of the Scandinavian and Swiss archaeologists, that the use of stone, bronze, and iron characterises three distinct phases in the civilisation of mankind in Europe, has been amply confirmed by the numerous discoveries made during the last five-and- Iwenty years. They are merely the outward marks of new stages of culture. Nor has the subdivision of the stone age into palaeolithic and neolithic, by Sir John Lubbock, been shaken ; they are separated from one another by the greatest changes in climate and geography, and in animal life, which have taken place since the arrival of man in Europe. Our author, however, denies this, and brings forward a series of examples derived, for the most part, from accounts either unverified by subsequent observers or in themselves equivocal, to show that the palaeolithic men possessed domestic . horses, oxen, pigs, dogs, and "hens," and were acquainted with the art of making pottery. We have no space to examine each of these statements in detail. We would merely say that the scientific exploration of caverns and tombs is by no means easy, and that until comparatively recently every- thing of unknown date found in them was supposed to belong to about the same age. Hence it is that the literature of archaeology offers to the author the exam- ples which he gives us. With regard to pottery it must be remarked that the vessels assigned to a palseolithic age, such as that of the Trou de Frontal, belong to well-known neolithic types, and that the domestic animals assigned to the same age are identical with those of the neolithic farmers and herdsmen. Caves were used by the neolithic peoples for purposes of habitation and burial. The duty, therefore, of proving that these things are of palseolithic age rests with the author ; — it is not the business of a reviewer to undertake proof of a nega- tive that they are not. The assertion, however, that no neolithic implements have been met with in the same cave as the so-called "fossil man of Mentone," whom we have always believed to belong to that age, is negatived by the polished celt from that cave which we have seen in the museum at St. Germains — an important fact, which, strangely enough, has escaped the notice of all who have hitherto written on the subject. We shall not repeat the arguments in favour of the palaeolithic age of the interments at Solutrd, which have already been combated in this review. We have always held that they are not earlier than Gallo-Roman times. The results of the further re- searches of MM. Ducrost and Arcehn, in 1875-6, show that, above the strata containing the remains of mam- moth, reindeer, horses, and palaeolithic implements, there is a stratum containing polished stone axes, iron and bronze implements, and interments of the neolithic, Gallo-Roman Burgundian times. The so-called palaeo- lithic are in all probability referable to one of these three ages, and from the fact of the skeletons resting at full length to one or other of the two last periods. The author is not content with bridging over the interval between the neolithic and palaeolithic times by the asserted occurrence in the latter of charac- teristics hitherto to be considered peculiar to the former. He tells us that 'extinct pleistocene animals lived "some of them down to historic and even post-Roman times." In support of this view he brings forward the occurrence of the mammoth from the peat bogs of Holyhead, Torquay, and Colchester, just as if there were no peat bogs in the pleistocene times — as, for example, the pre-glacial forest-bed, with mammoth and other creatures, on the shores of Norfolk and Suffolk. He relies also upon the fresh condition of the carcases of the Siberian mammoth as evidence against high antiquity, just as if ice would not pre- serve anything imbedded in it for an indefinite length of time. Palaeontologists will be astonished to hear that the cave- bear has been met with in the peat bogs of Denmark, and in Italy in association with relics of the neolithic age. The first of these reputed occurrences has been given up by M. Nilsson, and the second has not been verified by any competent authority. The latter observation will also hold good regarding the reputed occurrence of the cave lion in the peat of Holdemess. The Irish elk is asserted by our author to have been living in the marshes of Europe as late as the fourteenth century, a statement based on a speculation of Brandt's that the Machlis of Pliny and the Schelch of the Niebelungen Lied are identical with that animal. The palaeolithic imple- ments themselves (p. 220) are traced to the stone axe from Babylon, preserved in the British Museum, of a "palaeolithic type which reappeared in Europe when some of the ruder Turanian tribes migrated in that direction." It is not profitable to pursue this review further, for in this work one printed statement is treated as if it were of equal value with another, without any attempt being made to sift the improbable from the probable, or the true from the false. The facts are brought together in it very much hke flies — if one may indulge in a comparison — on a fly-paper, and bear the same relation to each other as the heterogeneous collection of dead and dying winged creatures there brought together in a strange fellowship. We regret that the writer should have spent so much time as he evidently has spent in collecting matter for a book written without scientific method, and which certainly does not prove that the age of the mammoth is removed from the present time by an interval of from six to ten thousand years. W. B. D. July ^, 1878] NATURE 247 RECENT MATHEMATICAL WORKS An Elementary Treatise on the Dynamics tf a System of Rigid Bodies^ with Numerous Examples. By E. J. Routh, M.A., F.R.S., F.R.A.S., F.G.S. Third Edition, Revised and Enlarged. 8vo, pp. 564, xii. (London : Macmillan and Co., 1877.) A Treatise on Statics, containing some of the Fitnda- ■ mental Propositions in Electro-Statics. By G. M. Minchin, M.A. 8vo, pp. 450, xii. (Longmans, 1877.) Lectures on the Eleinents of Applied Mechanics, com- prising (i) Stability of Structures j (2) Strength of Materials. By M. W. Crofton, F.R.S. Printed for the Use of the Royal Military Academy. Pp. 107. (C. F. Hodgson and Son, 1877.) Handbook of Natural Philosophy — Mechanics. By D. Lardner, D.C.L. New Edition, Edited and consider- ably Enlarged, by B. Loewy, F.R.A.S. Pp. 489, xxii. (Crosby Lockwood and Co., 1877.) The Book of Mechanics. Part I. — Statics. By R. Oscar Thorpe, M.A. (Stewart's Local Examination Series, 1877.) THE main features of Mr. Routh's admirable treatise are well known to students. The first edition, of 336 pages, appeared in i860 ; the second, of 492 pages, in 1868 ; the present consists of 564 pages, each page containing from a third to a half as much matter more than the page of the earlier editions. Some idea may thus be formed of the great amount of new matter. Of this increase take another proof: in the second edition the chapter on Small Oscillations took up pp. 273 to 322 ; in this edition the subject occupies pp. 325 to 403 ! The author assigns as a reason for this increase, " I have been led " to make these additions " because there are so many important applications which it did not seem proper to pass over without some notice." An interesting feature is the increased number of his- torical notices, though these are confessedly very slight, drawn from Montucla (by a misprint Montuela), Prof. Cayley's Report on Theoretical Dynamics (British Asso- ciation Report, vol. xxvi.), and other sources. Some of these are relegated to an appendix. A great number of original memoirs have been consulted and some of these of very recent date. We do not notice in Articles 282, 475, in which a discussion of the problem of Laplace's three particles is given, any reference to the author's paper on the subject in the Proceedings of the London Mathematical Society (vol. vi. No. 81, pp. 86-97), though of course the substance" of this paper is given in the text. We note this, because in both places Mr. Routh cites a reference, by M. Jullien, to a Thfese de M^canique, by M. Gascheau, which he has not succeeded in verifying. Perhaps a notice of this point in Nature may lead to the matter being cleared up for Mr. Routh's satisfaction. We have not ourselves met with this pamphlet by M. Gascheau. We could dwell much longer on this fine work, pointing out the numerous places where new proofs are given and entirely new matter is introduced, but we need only say that it must claim a very high place in our mathematical literature, and go far to remove the re- proach brought against Cambridge text-books by students who have become familiar with the works of continental mathematicians. There is an ample and diversified col- lection of problems which are given in the several chap- ters and appended to them. Following a common practice, the author gives a list of articles to which beginners should first turn their attention. Prof. Minchin purposely omits the prefix " Elementary," his main object being to give " a tolerably comprehensive view of statics." Very early in his book he introduces the conception of " virtual work," a term he adopts from the best French writers (Collignon, Delaunay, and others) in preference to "virtual velocities." His reason for bringing the subject so soon before the student is "the conception of work is the most prominent in modem physics, and, therefore, at the risk of being charged with prolixity, I have shown in the earliest chapters how all the conditions of equilibrium of a system may be obtained from the principle of virtual work independently of the usual mode of the reduction of forces." Graphic methods are used in the earlier portions ; a good feature, now that the treatises of Culmann, Bauschinger, and Cremona are in the hands of many English students. The subjects treated of are much the same as in other treatises in our hands, and the last chapter (pp. 403 to 450) is devoted to the theory of the potential ; the modes of treatment^ however, are different. Prof. Minchin attaches great importance to the solution of problems, and so takes care to solve a great many leading cases, and has done good service to students by these solutions and by the figures which he gives. The following remarks speak for themselves : — " It is charac- teristic of the system of * cramming,' which has been called into existence by modem competitive examinations, that the applications of mathematics, as exhibited in the solution of examples, are greatly neglected. A cause con- tributing to this objectionable system appears to me to exist in our mathematical treatises, many of which are almost wholly filled with unsolved problems and dry ' book- work,' which the student never learns to apply. I have therefore very largely illustrated the principles of the subject by solved examples, and I have attached at least as much importance to examples, all through, as to the abstract principles which they illustrate." We cordially commend the book, and hold that it is no unworthy companion of such text-books as those of Dr. Salmon and of Mr. Williamson. Prof. Crofton's book is a " Synopsis of a Course of Lec- tures on the Elements of the Theory of Structures and the Strength of Materials, forming the First Part of the Course of Applied Mechanics at present studied by the Gentlemen Cadets of the Royal Military Academy." The book requires to be read with some care, as the author's idea is that it should be supplemented by viva voce instruction and by experimental illustrations. It is thoroughly elementary, however, and avoids all aid from the differential and integral calculus. Great importance has been deservedly attached to the elegant method of diagrams of forces and to Culmann's graphical method. In the first part are considered such matters as frames, roofs, trussed beams, chains, and cords, and the stability of walls. In the second part come under notice resistance to stretching and to compression, theory of beams, moment of resistance in rectangular beams, girders, open girders, partially loaded beams, and other thoroughly practical matters. Prof. Crofton has wisely given a great 248 NATURE July 4, 1878 number of figures, and in addition to numerous unsolved exercises, has given very many worked-out problems. In his introduction he points out that " the practical man, unlike the theoretical, cannot choose his problems ; he must take those which the requirements of his art present, whether elegant and curious, or cumbrous and repulsive. Moreover, in his case, some solution of every problem must be obtained ; if he is unable to find a rigorous scientific solution he must make some further assumptions or have recourse to experiment ; he cannot lay the ques- tion aside." He goes on further to point out the differences between the two studies of theoretical and applied mechanics. The author has brought the subject before the notice of mathematicians in communications to the Mathematical Society and the Educational Times. Mr. Loewy has retained much of the elementary part of the late Dr. Lardner's treatise, having carefully revised it and brought it up to modern requirements. He has re-written, for the most part, the descriptive chapters on machines, clockwork, &c. Many new illustrations and a great number of solved exercises have been added, so that now the work is embellished with nearly 400 illus- trations. An account is given of the modern units of force and work (the dyne, poundol, &c.). The result is a neat and readable book on properties of matter, theory of machinery, and illustrations of the application of me- chanical principles in the industrial arts. We do not pretend to have read the work for it is full of matter, but what we have examined we have found interesting and carefully done. We have detected a few slips (typo- graphical, chiefly) in the solutions. A good feature is an index. The last book on our list is neatly got out and is doubtless adapted for the end in view, the author having written it for candidates for the Oxford and Cambridge Local Examinations. It is such a book as might have been compiled at any time within the last twenty-five years from the Cambridge text-books, for it keeps quite to the old Cambridge *' lines ; " it " aims at being simple, but not childishly so." The modern treatment of the subject has been altogether avoided. This is, perhaps, no fault of the author, but rather the exigencies of the above-named examinations have compelled him to move in this rut. There is a sufficient number of exercises taken from the examination papers, and a chapter is devoted to hints for, and examples of, the selection of problems. The figures generally are clearly drawn, but a cylinder on p. 43 is a sorry representation of such a solid. OUR BOOK SHELF Mikrographie der Glasbasalte von Hawaii : Petrogra- phische Untersttchung. Von C. Fr. W. Krukenberg. (Tiibingen, 1877.) The interesting facts made known of late years by Prof. Mohl, of Cassel, and Dr. Boficky, of Prague, as the result of their study of the microscopic characters of the vitreous and semi-vitreous rocks of basic composition, have rendered it eminently desirable that a thorough inves- tigation of the remarkable lavas of the Sandwich Islands should be undertaken by some competent observer. We therefore hail the appearance of the monograph now before us as supplying a want which has been felt for some time past by all who are interested in micro-petro- graphic studies. From the older analyses of the Sandwich Island lavas as tabulated by Herr Krukenberg, we learn that the composition of these rocks varies within very wide limits — the proportion of silica ranging from 3974 to 59"8o ; the author's own analyses, however, would seem to indicate much less widely separated rocks as having been subjected to examination by him, for the propor- tions of silica are given as from So'865 to 53"6i. The most remarkable circumstance about the composition of these Hawaiian lavas is probably the large proportion of iron-oxide which they contain, the percentage of this substance ranging from 13 to 33 per cent., while alumina is only present in small quantity, or is sometimes alto- gether absent. Herr Krukenberg first describes the curious structure revealed by the microscope in the compact basaltic glass in which are detected numerous beautiful examples of those skeleton crystals built up of crystallites to which Vogelsang first directed the attention of geologists, and to which the name of "chiasmoliths" has been applied. Among the perfectly-formed crystals porphyritically embedded in this compact or glassy mass, the author noticed felspar (both orthoclastic and plagioclastic) and olivine, but he failed to detect augite. The curious forms assumed by the threads of Pele's hair are admirably described in the work before us, and are illustrated by numerous figures. Gas bubbles appear to be very common in these glass threads, and they are often drawn out into elongated cavities or fine capillary tubes. Minute crystals are sometimes seen in the midst of the glass threads, which sometimes exhibit a concentric structure and at others a series of transverse striations. In the ordinary porous glass lava the author finds struc- tures intermediate between the chiasmoliths and the crys- talline plates seen in Pele's hair; his drawings, indeed, very admirably illustrate the mode of development of crystals in glassy magmas. The last variety of the Sand- wich Island lavas described in this monograph is the sphaerulitic ; but the sphaerulites of the basaltic rocks do not appear to differ in any essential point of structure from those so well known as occurring in acid vitreous rocks. In an appendix to the paper the author notices the existence in the Sandwich Islands of a true obsidian which yielded 76'io per cent, of silica. The monograph is illus- trated with four lithographic plates, and is a very valuable contribution to petrographic science. J. W. J. Preventive Medicine in Relation to the Public Health. By A. Carpenter, M.D., C.S.S., Camb. (London : Simp- kin, Marshall, and Co.) Under the title of "Preventive Medicine" Dr. Carpenter has reprinted lectures which he gave, during the summer session of 1876, at St. Thomas's Hospital. They were addressed to students, and the form in which they were first given has been preserved. At a time when, in the words of the Prince of Wales' s letter to the Society of Arts, " the supply of pure water to the population is ex- citing deep interest throughout the country," the volume will be found a convenient and ready rhum^ for those who wish to inform themselves on the more important questions that enter into the consideration of what is a good water supply, and what is to be done with fouled water. As is well known. Dr. Carpenter advocates sewage-farms as the proper way to dispose of sewage, and the chapters devoted to this subject enter into financial as well as scientific consideration. In speaking of the spread of epidemic diseases by water and by air Dr, (^arpenter explains the germ theor}^, but we cannot find that he even alludes to any other possible explanation. It appears as if he regards the germ theory of disease as really /r/K4, ^^7^1 NATURE 249 LETTERS TO THE EDITOR \The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts, Ne notice is taken of anonymous communications. \The Editor urgently requests correspondents to keep their letters as short as possible. The pressure on his space is so great that it is impossible otherwise to ensure the appearance even of com- munications containing interesting and novel facts.'\ The Phonogfraph I HAVE received the following interesting letter from Dr. Blake, Boston, U.S.A. :— W. H. Preece " You may possibly be interested in some recent experiments which I have made with the phonograph, and unless you have been pursuing the same course, may find them worthy of repetition. "I found that the groove in the cylinder, covered with tin- foil, became a resonator for the high scratching noise of the em- bossing point, materially interfering with the reproduction of the quality of the voice. " By stretching a thin layer of rubber tissue over the cylinder this resonating effect was done away with and the scratching noise materially lessened. This experiment was new to Mr. Edison, and has since been repeated with like success. "Since experiments made with the ferrotype telephone and phonograph-discs show that they transmit with almost astonishing accuracy the lighter over-tones of the human voice, but at the same time give especial prominence to certain over-tones to which the metal disc especially responds, I constructed a dia- phragm upon the principle of the human drum membrane, to be used as a reproducing disc ; the object being to employ a mem- brane which, from its structure and shape, would reproduce the lighter over-tones representing the quality of the voice, and at the same time ' cut off ' the sharper exaggerated over-tones embossed as such by the metal disc upon the tin-foil. The results of the experiments with such a membrane were very A small rod of light pine wood having a rubber pad at either end is placed between the boss which carries the embossing point and the centre of the membrane. This, the first form of disc constructed, worked very well. gratifying. After embossing with the metal disc, the curved membrane was substituted, and the voice reproduced from the phonograph without the sharper over-tones, with much more natural and agreeable quality and with more than double inten- sity. On using the curved membrane for embossing as well as reproducing, I found, as would be expected, that the quality of the voice was more accurately represented, and that the embos- sing could be done at a distance of over fifteen feet from the phonograph, and be reproduced with clearness. " Mr. Edison is now experimenting with this form of dia- phr^fm, and, I understand, with very good results. " The material used for these discs may be either stout felted paper (to be varnished on the outer surface when used for speak- ing) or drum-head, moistened and pressed into concave form before using. The principle governing the vibrations of such a disc is that of imparting the vibrations to the centre of a mem- brane the curve of which enables it to reproduce a large range of over-tones, its tension serving as a counterbalance to the central pressure. " Clarence T. Blake "W H. Preece, Esq., London." Physical Science for Artists - With reference to Mr. Norman Lockyer's and Prof. Briicke's observations on the appearance presented by the shadow of the earth at sunset or sunrise (Nature, vol. xviii. p. 223), I beg to be allowed to confirm them by my experience in Switzerl^d. Early starts for expeditions give one, among other good things, opportunities for seeing sunrise from the very beginning, and I have repeatedly seen the shadow of the earth, as it were, gradually driven do^vn by the illuminated portion of the sky, the boundary between them being very well marked and roughly circular like the horizon, but I think with a greater apparent curvature. At this distance of time (some years) I cannot remember anything of an effect of foreshortening such as Prof. Briicke notices. Once, in 1868, I saw an even more curious effect. As we stood at sunrise on a moderately sharp ridge running pretty closely north and south, at a height of 9,000 to 10,000 feet, there was an interval of appreciable duration in which it was a visible and striking fact that it was night on one side of the ridge and day on the other. F. Pollock Savile Club, Savile Row, W., June 27 Cyclones and Anticyclones I WILL endeavour to put into a ^v^itten form the ideas which have occurred to me respecting the law which, as I sup- pose, connects and governs the atmospheric phenomena which I see referred to in the newspapers as cyclones and anticyclones. I have seen it stated, as the result of observation, that in what- ever direction the wind may be blowing at any given time, if you place your back to it the barometer will be found to stand lower upon your left than upon your right. I have also seen it stated that what are termed cyclones are rotatory movements of the air occasioned by the meeting and passing one another of two currents of air moving in opposite, or nearly opposite, direc- tions, and that these cyclones or rotatory storms, though differ- ing much in area, have certain featiu-es common to most, if not all, of them ; namely, that the direction of their rotation is from right to left, or, in other words, the opposite of the motion of the hands of a watch, and that in their centre' is found a con- siderable diminution of atmospheric pressure. On the other hand, in what is termed an anticyclone, the direction of the rotatory movement is in the opposite direction, that is, from left to right, or in the same direction as the movement of the hands of a watch, while in the central region the barometer is found to be standing high. These various phenomena appear to me to be closely connected one with the other, and to be, in fact, due to the rotation of the earth upon its axis, which, having regard to its spherical form, makes it inevitable that the superincumbent air at the equator must rotate with the earth imder it at a much greater velocity than that which is near the pole. For it seems evident that a cxurent of air coming from the north travels into a region which is moving to the east more quickly than itself, and will therefore present itself as a north-east wind to the inhabitants of the more northern latitude, and not only so, but ^vill tend to arrest the air on its right or westerly hand, while it is left or abandoned by the more quickly eastward-moving air on its left or easterly hand. This consideration will explain, so far as northerly winds are concerned, the first-mentioned of the phenomena above referred to, namely, the lower glass on the left hand, the higher glass on the right. Taking next the case of a nor- therly ^vind, it will be obvious that in travelling northward it comes to a country moving westward more slowly than-. itself, and consequently appears as a north-west wind to the people over whose land it passes ; and not only so, but by pressing on the air to the right, or eastward side, it increases pressiu-e in that direction, while it tends to leave behind the more slowly moving air on its left, or westward side, thus again producing the first -mentioned phenomenon of a high glass on the right and a low glass on the left, so far as southerly winds are concerned. If this principle is considered with reference to a cyclone and the direction of the rotatory movement is also taken into account, it seems to be made clear that a cyclone is occa- sioned by the meeting and passing each other of a northerly and southerly current so that they pass each other on the left hand respectively. When this occurs the low pressure on the left or east side of the north wind coincides with the low pressure on the left or west side of the south wind, and thus a depression is formed round which the wind rotates. It follows that the west and south wind is found in the south and south-east side of the storm, 2 50 NATURE {July ^, 1878 while the north westerly current is on the north-west side, or as it is sometimes termed, the back of the storm. In the case of an anti- cyclone the whole thing is reversed. The two currents pass each other on their respective right hands. This enables the high glass on the right side of each to coincide with one another. The two winds instead of dragging away from each other, are pushing against each other, and form a heap of air round which they Cycl^ CvcLONK. — A A, a north-east wind; b b, a south-west wind; w, westerly- drift of A A due to difference of absolute velocities of earth's motion at different latitudes ; W, effective part of w, in producing rarefaction at r; e', effective part of b as above. Remit, rarefaction in centre of cyclone. w Anticyclone Anticvcwne. — Mutatis mutandis as cyclone. Result, condensation at centre of anticyclone. rotate^ not necessarily in the opposite direction to that of the cyclone. It would be interesting to know whether an anti- cyclone travels from north-east to south-west. Whether it does so or not I do not know ; but this is what would seem to follow if the above imperfectly-stated theory is a correct one. Eustace Barham Whirlwind As meteorologists appear to be taking much interest in whirl- winds and waterspouts, you will perhaps allow me to offer you a few notes respecting a whirlwind that passed over a moun- tainous part of Northumberland on April 14, 1869, and left indisputable evidence of the direction in which it revolved, a fact of some importance, and one in general so difficult to ascer- tain, that after much research I have never yet met with a description of either whirlwind or waterspout that can be con- sidered satisfactory in this respect. I have long held the opinion that the smaller whirlwinds and waterspouts are of the same nature, and follow the same laws, as the greater cyclones, although Sir Wm. Reid, at p. 461, vol. i. of his *' Law of Storms," is of a contrary opinion, founded on observations of waterspouts at sea, where it is extremely difficult to judge by the eye in which direction a spout is rotating. The cases where, as in America, attempts have been made to settle this point by the direction of trees thrown down by the ^^ hirlwind are very unsatisfactory ; and there is nothing definite X ^ on this head to be met with in the description of upwards of three hundred whirlwinds described by Peltier in his work "Sur les Trombes." The 14th of April, 1869, was exceedingly wild and stormy, and so dark at mid -day that we could scarcely see to write at a meeting of churchwardens in the vestry of Hexham Abbey Church, Having heard of the whirlwind at Sweethope, about ten miles north of Hexham, I went thither in July, 1869, ac- companied by my friend Dr. James Smith, of Newcastle-upon- Tyne. We passed the night at Sweethope Farm (a), and examined the course of the meteor carefully. Masons were still engaged rebuilding a stable and boathouse (c) which stand at the northern extremity of the embankment that separates the larger from the smaller lake, from which issues the River Wansbeck, that flows past Morpeth, about twenty miles to the eastward. The whirlwind was first noticed by the inmates of Mr. Rob- son's house, A, as it passed a small plantation on a hill at b, and was seen to travel in a north-westerly direction across the road at D, along the embankment between the two lakes, over the boathouse, c. From this point it passed a plantation of young trees, through which it cut a broad lane, and afterwards over- turned a haystack. Mr. Robson informed me, in a letter, that "trees were torn up by fifties, some broken off about midway, and carried a con- siderable distance in the air. Stones were turned up that would have taxed the powers of three or four strong men. Several sheep and lambs were lifted up into the air and killed by the fall; others were carried up, and, falling into the lake, were drowned. There was a tremendous thunderstorm, with forked lightning and very large hailstones. It did not travel very fast, and was like a large volume of smoke." The boathouse was entirely unroofed and the nails drawn out of the planks of a floor of a room in the upper part of the building. The small plantation at A is 812 feet above the sea- level. Nothing was seen or heard of the whirlwind beyond the limits of the diagram, which is copied from the Ordnance Survey Maps on the scale of an inch to a mile. So far, the Sweethope whirlwind presented only the usual fea- tures of its class, and we were about to depart, after some good sport among the fish in the lakes, when Mr. Robson's son men- tioned to me that the whirlwind, in crossing the road (at d), had thrown part of the wall into the road and another part into the field, a significant fact of which we at once proceeded to examine the details. At the point D in the diagram the wall runs m a direction nearly north by east, and has been about four feet high. At the southern end we found about two feet of the July 4, 1878] NATURE 2CI upper part for a distance of eighteen yards thrown into the field. Then came about 9 yards of wall quite undisturbed, and after- wards thirty-six yards half down, but lying in the roadway on the opposite side of the wall. About seventeen yards of the coping-stone at the extreme northern end of the broken wall was also thrown into the road. Fortunately the whole lay at the time of our visit just as when the whirlwind had passed, and proved conclusively that, in this case at least, the order of rotation was the same as that of the cyclones of the northern hemisphere. Thomas Dobson Marine School, South Shields, June 22 I Zoological Geography — Didus and Didunculus I AM at a loss to understand how Didunculus can be called "a near congener" of the Dodo, as Mr. Searles V. Wood, apparently following Dr. Litton Forbes (whose paper I have not seen), terms it {suprh, p. 220). The two birds, so far from being congeneric, belong to perfectly distinct groups of the Order Columbce, and nearly thirty years ago Bonaparte treated them as the types of distinct families — Didida and Didunculida — an example which has been generally followed by the best authorities. If Mr. Wood will refer to a paper in the Philo- sophical Transactions for 1869 (pp. 327-362) I think he will see that there is good ground for not attaching much importance to the slight and superficial characters in which Didunculus resembles the Didida. Alfred Newton June 30 A Subject-Index to Scientific Periodical Literature I BEG permission to ventilate in your columns a subject which must make itself felt more or less to all your readers, viz., the want of some subject-index to the vast amount of material scat- tered about in the numerous scientific periodical publications of the present day. It is true we have the admirable catalogue of the Royal Society, but unless you are acquainted with the name of every author who has wTitten on your subject, it is nearly hopeless attempting a complete bibliography of it. Now I would suggest whether an index to the Royal Society's catalogue cannot be made on the same plan that has been adopted by the com- mittee of the new edition of " Poole's Index," viz., by getting different societies, libraries, or individuals to take certain parts of the work. ITie following is a short abstract of how this conmiittee have set about their work ; any of your readers who wish for further information will find it at pp. 109-206 of the '* Transactions and Proceedings of the Conference of Librarians, London, 1878," and on p. 201 a short specimen may be seen. The index is made on sheets of foolscap, and the indexer has nothing to do with alphabetical arrangement ; he makes his entnies in the order the articles occur in the volume at which he is working ; these sheets are then sent to the editors, who cut ^them into slips and work them into alphabetical order with the material coming in from other sources. By this method complete uniformity is maintained ; for should the indexer have a peculiar idea of his own how any particular part should be done, his peculiarity is put right at the central bureau or editorial office. I have said this should be an index to the Royal Society's catalogue, but if this scheme is ever carried into execution I would strongly urge that the index should be made from the periodicals themselves, and not from the entries in the Royal Society's catalogue, as it is absolutely impossible to index a paper properly from the title only ; and another advantage is that under this plan the work could be better carried out, as each indexer could confine himself to his own branch of study ; whereas if the index were made from the catalogue itself, it must be cut up into alphabetical portions, and each man would have to do a variety of subjects. This may seem to many too large a matter even for consideration, but for many years so was a good alphabetical catalogue of the different scientific papers ; this has been conquered by the Royal Society, and if that learned body would constitute itself the central bureau, I think willing workers would soon be found, and the success of the index be assured. Of course all this would cost money, but surely an appeal might fairly be made to scientific societies and individuals to help in this work, which would be so great a help to the "advancement of science." Jas. B. Baii.ey Oxford A NEW TRIUMPH OF CHEMICAL SYN- THESIS 'T^HE year 1868 was a marked epoch in the progress of -*■ chemical synthesis as well as of tinctorial processes. The German chemists, Profs. Graebe and Liebermann, succeeded at that date in preparing from the hydrocarbon anthracene manufactured from coal tar the brilliant dye- stuffs hitherto won from madder, and in establishing also the chemical constitution of these various com- pounds and their relationship to other well-known bodies. This was the first instance in which the chemist had succeeded in artificially preparing colours occurring in the vegetable kingdom ; and although the manufacture of artificial madder colouring matters has assumed at the present day colossal proportions and bids fair to entirely supersede the preparation of the natural products, it has hitherto remained the only instance of the kind in the history of chemistry, all other vegetable and ani- mal dyes obstinately refusing to disclose the secret of their composition and be classified among the compounds of well-defined molecular structure. Within the past few weeks the madder colours have ceased to occupy this unique position. Modern chemistry has succeeded in preparing synthetically none other than common indigo, the well-known product of the halts tinctoria, and Nerium tinctorium of India and South America. This discovery is likewise due to a German chemist, Prof. A. Baeyer, the genial successor to the chair of Liebig at Munich, one of the most indefatigable and suc- cessful investigators of our day. For a score of years he has been seeking to solve the problem of the constitution of indigo and its synthetical preparation. Slowly and patiently he has gathered together and elaborated one fact after another, until finally, at the last session of the German Chemical Society, he was able to announce the completion of the long research and the discovery of the last link in the chain of synthetic reactions leading to the formation of indigo. We will sketch briefly the various steps in this syn- thesis, which is not only one of the most brilliant chemical achievements of the present year, but affords an unusually interesting glimpse into the methods and aims of the modem chemist. Indigo blue, or indigotine, possesses the formula QHgN O, and, from the products of its decomposition, aniline, orthoamidobenzoic acid, &c., has long been regarded as closely allied to the benzene series. At- tempts without number have been made to show the nature of this connection by starting from benzene compounds, but hitherto with fruitless results. As in the case of the alizarine compounds, where Graebe and Liebermann first found that anthracene was obtained from alizarine by reducing agents, so has the first step in the solution of the indigo problem been to study care- fully the various compounds resulting from successive decompositions, each in turn yielding a body of a simpler constitution. Passing from one compound to another, Prof. Baeyer finally reached alpha-toluic acid or phenyl- acetic acid, CeH5.CH2.COOH, a not uncommon body, easily prepared from cyanide of benzyl. Here he stopped, and began to retrace his footsteps. The first reaction was to replace one of the hydrogen atoms in the phenylic group oi phenylacctic acid, (A.) CeHg.CHs.COOH, by the group NOg — a familiar operation effected by treatment with nitric acid— and giving, among other compounds, ortJio-nilrophenylacetic acid, iv.\ cw XCH2.COOH This, when reduced by nascent hydrogen—/.^., sub- mitted to treatment with a mixture of tin and hydrochloric 252 NATURE \_7uly i^, 1878 acid — gives the corresponding ortho-amidophenylacetic acid, ic\ PTlVCHg.COOH In a neutral solution this acid is changed into its anhy- dride by the elimination of a molecule of water forming And here we leave the long names indicative of the struc- tural composition of the compounds : for Prof. Baeyer has found that this anhydride is identical with oxindol, one of the derivatives of indigo. The next steps are to introduce the nitroso group, NO, forming nitroso-oxindol, and to reduce this as before to amido-oxindol, (F.) C.H.<(™(NH.).CO\ This compound, when oxidised with chloride of iron or copper, or with nitrous acid, is changed entirely into isatin, a substance resulting from the oxidation of indigo, which already in 1870 Prof. Baeyer, by the action of phosphorus trichloride, had changed back into indigo-blue, N.CgH^.CO.CH (H.) II II , N.CgH^.CO.CH by the union of two molecules and the elimination of two atoms of oxygen. With this last transformation the synthesis was completed. Although the operations are too numerous and too costly to allow at present any hope of the practical utilisation of this ingenious succes- sion of reactions, the series presents still a remarkable example of the possibilities in the hands of the organic chemist, of the powers of combination requisite for the successful pursuit of modern synthetical research, and of the attractions which draw to this province the majority of our leading chemists. T. H. N. BIOLOGICAL NOTES The Comet-Forms OF Star-Fishes. — Ernst Haeckel, in a recent number of the Zeitsch. wiss. Zool. (1878, Sup- plement 3), draws attention to these forms, and the sup- port which the facts recently established as to the power possessed by certain star-fishes of multiplying by throwing off their arms, lends to his theory of the origin of the Echinoderma by the continually increasing integration or centralisation of a radially-connected colony of worm- like persons. The phenomenon of self-division across the disc has been observed in species of Asteracanthion (Uraster) by Lutken and Kowalewsky ; the production of comet-forms depends, however, on the separation of single arms, which then reproduce the whole disc and remaining arms by budding. Martens, in 1866, observed this in the case of a Luidia (Ophidiaster) in the Red Sea. Kowalewsky found that it was a common process with similar species and same locality. Sars observed it in Brisinga. Studer has described the regular occurrence in Labidiaster of a spontaneous casting off of the arms, but not the regeneration of disc and arms on the sepa- rated arms. Sir John Dalyell observed the whole process of reproduction of the disc on a single detached arm of Asteracanthion {Uraste}') glacialis. The support which these facts lend to the " Astrocormus " theory is not of that value which Haeckel would assign to them, for such physiological tests of morphological doctrine are neces- sarily delusive. We have only to remember the facts as to cuttings and graftings in organisms generally in order to see that no special argument can be based upon them as to details of morphological composition. Haeckel proposes to diride the Echinoderms or Estrellas as follows : — Group I. — Protestrellas : Class I. Asteriae. Group II. — Anthestrellae : Class 2. Ophiuras ; Class 3. Crinoida. Group III. — Thecestrellae : Class 4. Blastoida ; Class 5. Echinida ; Class 6. Holothuriae. The second and third groups have developed from the first as diverging branches, whilst the Holothuriae are modified descendants of Echinida. The resemblances between Gephyrea and Holothurians are declared by Haeckel to be entirely due to parallel adaptation (homo- plasy), the pair of branched excretory organs of Bonellia, &c., being totally unrelated to the dendriform water-lungs of Holothurians, which are five in number in primitive forms and agree with branched inter-radial coeca (not the so-called "hepatic " coeca) of the intestine found in cer- tain star-fishes (Archaster, Astropecten). E. R. L. The Transformations of Blister-Beetles. — Ac- cording to Dr. C. V. Riley, who has studied these creatures for some years, the young of all vesicants belonging to the Meloidae, develop in the cells of honey-making bees, first devouring Ihe ^^% of the bee and then the honey and bee-bread. They are all remarkable for their hyper- metamorphosis, passing through several larval stages. The young Meloes are at first simple larvse called triun- gulins, running actively about, climbing to flowers visited by bees, to which they attach themselves. They have stout thighs and claws, but feeble jaws. Only a few can get attached to the proper bees, the others must perish. Once in the cell the creature eats the bees' ^g^, and then moults and assumes the second larval condition. In this state it is clumsy and little locomotive, and feeds on the honey store. It then becomes a pseudo-pupa, and later a third larva within the partially-rent skin ; the true pupa stage being still later. Another genus of the family is Hornia, of which a remarkable species is found around St. Louis, with the elytra and wings extremely reduced. The Hornia resides mostly in the galleries oi Anthrophora sponsa, out of which it can scarcely crawl. The hyper- metamorphosis is of the same character as in Meloe {Atnerican Naturalist, April). The genus Epicauta ex- hibits a very parallel history. Curious Social Relations.— Stories about prairie dogs, owls, and rattlesnakes are well known, but trust- worthy scientific observations about them are not very numerous. Mr. S. W. Williston {American Naturalist, April) gives the results of several years personal observa- tions. He says that prairie dogs can thrive even in the dry scorched deserts of Southern Colorado, and the cold bleak Laramie plains. They are very provident in summer for winter, but yet emerge in spring much reduced in plumpness. At the approach of danger signals of distress are given, and when actually attacked they get into their mounds with wonderful speed, escaping beyond reach even when a rifle has scattered the brains of the animal. The burrowing owl not unfrequently occupies the same hole ; the prairie dog pays little heed to it but tolerates it. The owls present a most ridiculous appearance, standing during the day at the entrance of their dwellings, in an attitude of the deepest contemplation ; at the appearance of an intruder they begin the most comical bowings and curtsies, and at last with a cry like a watchman's rattle fly off to a neighbour- ing mound. The rattlesnakes cannot be said to be friendly with either of these creatures. Out of many hundreds of rattlesnakes destroyed by Mr. Williston, a number had devoured the young of the prairie dog, but none the young owl. The occupancy of a burrow by a July ^, 1878]^ NATURE 253 rattlesnake does not, however, prevent the entrance of the dog ; the rattlesnake is never wanton, and only defends itself and takes necessary food. The dog will pass by it to enter its burrow without being molested. Cleistogamous Flowers in Grasses.— Mr. C. G. Pringle has discovered in Western Vermont cleisto- gamous flowers in several grasses, especially Datithonia spicata. The latter has many flowers totally concealed in the sheaths, the glumes and pales being much simpli- fied, but the sexual parts being perfect and producing seeds. This plant is spreading rapidly in Vermont. The seeds borne on the top of the culm fall mostly at midsummer and lodge close to the parent plant, but the concealed seeds stored around the culm remain till these are disjointed and driven about by the autumn and winter winds ; consequently, a wide means of dissemina- tion is provided. ON THE VIEW OF THE PROPAGATION OF SOUND DEMANDED BY THE ACCEPT- ANCE OF THE KINETIC THEORY OF GASES I. T T is an accepted fact that the molecules of a gas are •*■ in motion among themselves in their normal state, and incapable of acting on each other at a distance ; so that a theory of the propagation of sound, based upon the contrary suppositions that the molecules of a gas are at rest in their normal state and capable of acting on each other at a distance, cannot possibly be tenable. It there- by becomes necessary to inquire what view of the propa- gation of sound is demanded by the acceptance of the kinetic theory of gases ; and this inquiry would appear to be all the more important in view of the fact that the mechanism of the propagation of sound in gases forms the physical basis of a great part of acoustics, or the ground- work upon which a number of its problems depend — the physical basis that underlies a system being admittedly the most important of the whole. 2. The molecules of a gas being in motion among themselves, it becomes evident after a very brief con- sideration of the question, that the only way in which a small impulse (or variation of velocity) termed a " wave " can be propagated through a gas, is by the exchange of motion normally going on among the molecules of the gas. For the molecules have no other mode of acting upon each other, excepting by exchange of motion. The rate at which this "wave" (or small variation of velocity) is propagated through the gas, will therefore depend on the rate at which the molecules exchange motio7t, i.e. on the normal velocity of the molecules of the gas. The sole condition determining the velocity of propagation of sound in a gas is therefore the velocity of the molecules of the gas. Here, therefore, we have a very simple condition for the velocity of sound (on the basis of the kinetic' theory), or the velocity of sound becomes thus dependent only on one condition. This simplicity is characteristic of the rest of the kinetic theory, and is (it may be added) the recognised quality of scientific truth. In gases of the most diverse densities, specific gravities, pressures, and temperatures, the velocity of sound is only dependent on one condition, viz., the velocity of the molecules, of the gas. 3. That the velocity of sound is independent of density, will be evident from the consideration that the molecules of gas are almost indefinitely small compared with their length of free path, and also the time of a collision is indefinitely small compared with the time taken to traverse the free path, so that it does not matter how many collisions (or exchanges of motion) occur along the line of passage of the impulse (or " wave "), but simply on the rate of motion of the molecules conveying the impulse. So (to take a simple analogy by way of illustration), it I does not matter how many couriers are along the line of route conveying a message, but on the rate of motion of the couriers. Adding to the number of molecules in unit of volume of a gas (or adding to the density) does not, therefore, alter the velocity of sound in a gas, because it does not alter the velocity of the molecules which (by their exchange of motion) propagate the wave. The old theory supposes that the velocity of sound is here un- altered, because increased density diminishes the velocity of propagation of the wave, and increased pressure (attendant on the increased density) augments the velocity of the wave, and thus the two conditions counteract each other. On the kinetic theory, neither of these conditions can have any effect, and therefore the explanation of the unaltered velocity of the wave is perfectly simple, being the cosequence of the unaltered velocity of the molecules which propagate it. It is unnecessary to comment on the contrasted simplicity of the view on the kinetic theory ; which is, moreover, the true view, if the kinetic theory be accepted. 4. That the velocity of sound on the kinetic theory is independent oi pressure, is sufficiently clear at first sight ; for pressure evidently could not influence the rate at which the molecules exchange motion among each other, through which means alone the impulseis conveyed. 5. That change of specific gravity (or molecular weight) can by itself have no effect on the velocity of the sound-wave, is evident from the fact that it cannot matter whether the molecules exchanging motion among each other (and propagating the impulse) be heavy or light, provided their' velocity be the same. It has been (as is known) demonstrated, generally from dynamical principles, that a system of bodies in free collision all tend to acquire the satne absolute energy. Hence the velocity of each body depends on its mass (or varies inversely as the square root of its mass). So the mass of the molecules of hydrogen being (as is known) one sixteenth that of the molecules of oxygen, the velocity of the molecules of hydrogen is four times greater than that of the molecules of oxygen ; and accordingly for this reason the velocity of sound in hydrogen is exactly four times greater than its velocity in oxygen — not, however, because the molecules propagating the wave are heavy or light. The molecules of hydrogen in their normal exchange of motion, move at four times the speed (com- pared with those of oxygen), and therefore propagate by this exchange of motion the sound-wave at four times the speed. The specific gravity (or molecular weight) of the gas has evidently nothing whatever to do with the rate of propagation of sound. The reason why the velocity of propagation of sound appears to depend on the molecular weight of the gas is because the velocity of the molecules of the gas depends on the molecular weight. 6. So also the velocity of sound is independent of the temperature, provided the molecular velocity remains the same. Of course this could only be true of different gases {i.e., of gases of different molecular weights), which — as is known — may be at different temperatures and yet possess the same molecular velocities. In one and the same gas of course the temperature could not be altered without altering the molecular velocity, for the " heat ^ itself consists in the motion of the molecules of the gas. This is therefore evidently the cause why the application of heat to a gas increases the velocity of sound. The addition of " heat " simply represents (as is known) the addition of velocity to the molecules of the gas, which consequently, by their exchange of motion, propagate the wave at a greater rate. The explanation of the increased velocity of sound in a heated gas is thus simple and direct. On the old theory the increased velocity of the sound-wave in a heated gas is referred to the dimi- nished density of the heated gas (attendant on its expansion) ; and when the gas is confined, to its increased pressure. Surely this is at best a somewhat laboured and 254 NATURE [7uly ^, 1878 indirect way of accounting for a fact, and (as we have seen) according to the kinetic theory it cannot hold, since according to this theory, detuity and pressure can have no influence on the velocity of the wave, and on the other hand it is a known fact that the velocity of the molecules in their exchange of motion (by which means alone they can propagate the wave) is increased by the heat — indeed this augmentation of velocity itself represents the added "heat" This explanation of the increased velocity of a sound-wave in a heated gas commends itself therefore not only by its simplicity, but as a matter of scientific truth. 7. This serves also to explain in a direct and simple manner the relation the velocity of sound in a gas bears to the temperature. The absolute " temperature " of the gas represents (as is known) simply the energy of the molecules. The velocity of the molecules (as of any moving system of bodies) is proportional to the square root of their energy, and therefore proportional to the square root of the absolute temperature (since the " tem- perature " represents the energy). The velocity of sound, therefore (which is proportional to the velocity of the molecules), is thereby proportional to the square root of the absolute temperature of the gas. 8. To afford a more distinct idea of the mode of pro- pagation of the wave and the physical effect (condensa- tion and rarefaction) produced on the gas by its passage, the following considerations may serve. It is an important fact to keep in view that a system of bodies in free col- lision, such as the molecules of a gas, do not move in a mere chance or perfectly irregular manner, but a certain regularity exists. It has been mathematically proved that a forcible self-acting adjustment goes on among the colliding molecules of a gas so as to cause them to move in a special tmiwaeT, viz., so that an equal number of mole- cules are moving in all directions, or as many molecules are moving in any one given direction as in the opposite. This mode of motion, if artificially disturbed, will correct itself. It is this special mode of motion (or movement of the molecules equally towards all directions) that pro- duces the perfect equilibrium of pressure in all directions, observed in a gas. 9. From the fact that as many molecules are moving in any one direction as in the opposite ; it follows that if an imaginary plane be placed in any position outside a vessel •containing gas, the number of molecules (in the vessel) which at any instant are approaching the plane, is equal to the number which at the same instant are receding from it. Or otherwise, if we suppose any imaginary straight line in a gas, and visualise the molecules upon this line, then, as many molecules are moving in one direction as in the opposite. In the case of those molecules which are moving obliquely to the line, the resolved component of the motion in the direction of the line can be taken. This consideration enables the mode of motion of the molecules of a gas in its normal state, and the manner of propagation of waves through that mode of motion, to be illustrated in a very simple manner. 10. In the annexed diagram, let i, 2, 3, &c., represent a line of spheres moving in such a way that as many spheres are moving in one direction as in the opposite. A^ the spheres marked with the odd numbers may be supposed to move in one direction, while those marked with the even numbers move simultaneously in the reverse direc- tion, the vis viva in the one direction balancing that in the opposite direction (as is the case with a gas). Each alternate sphere thus simply oscillates backwards and forwards in opposite directions within the limits repre- sented by the dotted lines in the diagram, the spheres continually rebounding from each other, and the line of spheres tending to open out or expand and separate the final controlling surfaces A and B (like the expansive action of a gas). It will be observed that this is in prin- ciple the only mode of motion possible by which the spheres can be in equilibrium ; or half move in one direc- tion and half in the opposite, so that the centre of gravity of the whole is at rest, in analogy with the centre of gravity of a portion of gas (the vis viva being at the same time balanced). There are only minute differences of detail as regards the comparison with a gas, none of principle. One detail is that every alternate molecule (in a line of molecules taken in a gas) does not necessarily move in an opposite direction, but it is rigidly true (on account of the vast multiplicity of molecules) that in any appreciable por- tion of a line taken in a gas, as many molecules are moving in one direction as in the opposite ; for if not, the gas could not be in equilibrium in the direction of this line, whereas it is known to be in equilibrium in every direction. Another detail is that some of the molecules of a gas are moving obliquely to such an imaginary line, so that the mean path of the molecules is generally greater than that repre- sented by the spheres. These details cannot however in the least affect the principle, and therefore the above method of illustration will serve (keeping in view the small differences mentioned) to convey a perfectly just idea of the character of the motion of the molecules of a gas in its normal state, and the way in which through that mode of motion "waves" are propagated through the gas. It is evident that an illustration is desirable in order to visualise clearly the facts. ^ 11. Suppose, now, a slow oscillatory motion in the form of a movement of vibration to be communicated to the plane A. The plane B may be supposed removed and the line of spheres extended indefinitely from the plane A. Then at the first forward swing of the plane A, the sphere I will receive an increment of velocity which it will transfer by collision to sphere 2, the sphere i returning with its n