MICROLOCICAL LABORATORY AND SCHOOL OF NATURAL SCIENCE. GRATIS AND POST FREE. THE NEW COLLECTION OF Scientifically arranged Catalogue of Megascopic and Microscopic 336 SPECIMENS AND SLIDES OF ROCKS, Specimens is now being prepared. Gentlemen are invited to send in their applications without delay, as only 5000 copies will be issued. Sample Slide of expertly prepared ROCK SECTION, 1/-, post free. Metals, Minerals and Rocks expertly mounted for Microscope, 1/- each, from material supplied. LESSONS IN PRACTICAL LITHOLOGY BY CORRESPONDence. A vacancy for one Geological Student, desirous of passing with high distinction in University or Civil Service. Small premium. Pocket-money allowed. Apply:- THE DIRECTOR, MICROLOGICAL LABORATORY, 11 ASPENLEA ROAD, HAMMERSMITH, LONDON, W. MINERALS, ROCKS, FOSSILS. A large stock of BRITISH AND foreign mINERALS always on view. CORNISH MINERALS ROCKS, MINERALS, FOSSILS. For Collectors, Students, Technical Schools, Colleges, &c. COLLECTIONS IN POLISHED DEAL BOXES. 25 Specimens, 5/6; 50 do., 10/6; 100 do., 21/-; 200 do., 42/20 Coal Measure Rocks and Fossils, 12/6; do., larger, 15/-. Adapted for the Board of Education Examinations in Geology, Physiography, and Mineralogy. A large stock of Minerals, Rocks, Fossils and Microscopic Objects for selection. Specimens sent on approval. Cabinets, Geologists' Hammers, Chisels, Card Trays, Glass-capped Boxes, Models of Crystals, &c., &c. NEW CATALOGUE POST FREE. THOMAS D. RUSSELL, 78 Newgate St., London, E.C. LIVING SPECIMENS FOR THE MICROSCOPE. Volvox, Spirogyra, Desmids, Diatoms, Amoeba, Arcella, Actinosphærium, Vorticella, Stentor, Hydra, Floscularia, Stephanoceros, Melicerta, and many other specimens of Pond Life. Price is. per Tube, Post Free. Helix pomatia, Astacus, Amphioxus, Rana, Anodon, &c., for Dissection purposes. THOMAS BOLTON, 25 BALSALL HEATH ROAD, BIRMINGHAM. MARINE BIOLOGICAL ASSOCIATION The following animals can always be supplied, either living or preserved by the best methods : Sycon; Clava, Obelia, Sertularia; Actinia, Tealia, Caryophyllia, Alcy. onium; Hormiphora (preserved); Leptoplana; Lineus, Amphiporus, Nereis, Aphrodite, Arenicola, Lanice, Terebella; Lepas, Balanus, Gammarus, Ligia Mysis, Nebalia, Carcinus; Patella, Buccinum, Eledone, Pectens Bugula, Crisia, Pedicellina, Holothuria, Asterias, Echinus. Ascidia, Salpa (preserved), Scyllium, Raia, &c., &c. For prices and more detailed lists apply to Biological Laboratory, Plymouth. THE DIRECTOR. according to H. ROSENBUSCH: "Elemente der Gesteinslehre, 2d ed. 1901." Accompanied by a text-book: "Practical Petrography," giving a short description of the polarizing microscope and its application, and also of the macroscopical and microscopical features of every specimen of this collec tion, by Professor Dr. K. Busz of the University of Münster. This collection is intended for the practical use of students, and contains typical representatives of all important types of rocks; it is composed of 277 massive rocks (94 deep-seated rocks, 50 dike rocks, 133 volcanic rocks), 28 sedimentary, and 31 crystalline schists. Out of it two smaller collections of 250 and 165 specimens have been selected. The prices are as follows:Collection I. 380 Marks. 336 Specimens of Rocks 336 Slides ... 420 39 270 Ia. 310 COLLECTIONS OF MINERALS, FOSSILS, METEORITES, PURCHASED FOR CASH OR EXCHANGED. The fifth edition of Catalogue No. 4, Petrography, has just been published (210 pages), and will be sent free of charge on application. Dr. F. KRANTZ, RHENISH MINERAL OFFICE, BONN-ON-RHINE, GERMANY. ESTABLISHED 1833. WATKINS & DONCASTER, Naturalists and Manufacturers of CABINETS AND APPARATUS FOR ENTOMOLOGY, BIRDS' EGGS AND SKINS, AND ALL SPECIAL SHOW-ROOM FOR CABINETS. N. B. For Excellence and Superiority of Cabinets and Apparatus, refer ences are permitted to distinguished patrons, Museums, Colleges, &c. A LARGE STOCK OF INSECTS, BIRDS' EGGS AND SKINS. SPECIALITY.-Objects for Nature Study, Drawing Classes, &c. Birds, Mammals, &c., Preserved and Mounted by First-class Workmen true to Nature. All Books and Publications on Natural History supplied. 36 STRAND, LONDON, W.C. (Five Doors from Charing Cross.) Our Catalogue (96 pp.) Post free on application. MICROSCOPICAL PETROGRAPHY. Gentlemen interested in the above study are invited to send to JAMES R. GREGORY & CO., 1 Kelso Place, Kensington Court, London, W., for a Prospectus of THE TWENTIETH CENTURY ATLAS OF MICROSCOPICAL PETROGRAPHY, now being issued in Twelve Monthly Parts, each Part containing Four Fine Half-Tone Plates, and also Four actual Rock Sections. Subscription in advance, either Monthly, 7/-; Quarterly, 21/-; or for the whole Series of 12 Monthly Parts & 48 Sections, £4 4s. NOTICE.-Advertisements and business letters for NATURE should be addressed to the Publishers; Editorial Communications to the Editor. The telegraphic address of Nature is “ PHUSIS," LONDON. Printed by RICHARD CLAY AND SONS, LIMITED, at 7 & 8 Bread Street Hill, Queen Victoria Street, in the City of London, and published by MACMILLAN AND CO., LIMITED, at St. Martin's Street, London, W.C., and THE MACMILLAN COMPANY, 66 Fifth Avenue, New York.-THURSDAY, March 9, 1905. THE VERY LATEST "TYPE" OF EXTENSIMETER IS, THE "O'TOOLE." A Simple, Convenient, Accurate, and Reliable Instrument, designed by the Rev. Father O'Toole, Black Rock College, Dublin, for Students' use in determining the coefficients of expansion of metal rods, at a moderate price. SOLE The Apparatus may be adapted for lecture demonstrations, by the simple expedient of using an optical lever. Price, with steamjacket, graduated spirit level and micrometer gauge, complete, £22:0 MAKERS PHILIP HARRIS & CO., LTD. 144 EDMUND ST., BIRMINGHAM, AND 179 GT. BRUNSWICK ST., DUBLIN. MACMILLAN CO.'S LIST. LANDSCAPE IN HISTORY & OTHER ESSAYS. By Sir ARCHIBALD GEIKIE, D.C.L., F.R.S. 8vo. 8s. 6d. net. DAILY TELEGRAPH.—“In a sense Sir Archibald Geikie's Landscape in History' may be said to open up an entirely new branch of study for us. And most attractively has the learned author done this. To those who have shared the current notion that geology and its sister science physiography is necessarily dull, the book before us will come as a revelation. They will find the study of the earth's surface in relation to man, his history and his civilisation, made realistic, as vivid and entrancing as any historic romance. A MANUAL OF QUATERNIONS. By CHARLES JASPER JOLY, M.A., D.Sc., F.R.S., Sec. R.I.A.; Fellow of Trinity College, Dublin; Andrews' Professor of Astronomy in the University of Dublin, and Royal Astronomer of Ireland. 8vo. 10s. net. AN INTRODUCTION TO THE CALCULUS. BASED ON GRAPHICAL METHODS. By GEORGE A. GIBSON, M.A., F.R.S.E., Professor of Mathematics in the Glasgow and West of Scotland Technical College. Crown 8vo. 3s. 6d. SCHOOL WORLD." The book is full of interest, both on account of the many interesting problems in which it abounds, and because it contains several methods of treatment which are not found in the usual text-books." WORKS ON GEOMETRY TO MEET THE NEW REQUIREMENTS. PRACTICAL GEOMETRY FOR BEGINNERS. By V. LESSONS IN EXPERIMENTAL AND LE NEVE FOSTER and F. W. DOBBS, Assistant 2s. 6d. By W. D. A NEW GEOMETRY FOR JUNIOR FORMS. By S. BARNARD, M.A., and J. M. CHILD, B.A. Cantab. Containing the Substance of Euclid, Books I., III., 1-31, the easy parts of Book IV., and a description of the forms of the Simpler Solids. Crown 8vo. 2s. 6d. This volume contains all the Practical and Theoretical A NEW GEOMETRY FOR SENIOR FORMS. By S. THE PRACTICAL GEOMETRY. By H. S. HALL, M.A., and F. H. STEVENS, M.A. A SCHOOL GEOMETRY. By H. S. HALL, M.A., and F. H. STEVENS, M.A. Crown 8vo. PARTS I.-VI.-Containing Plane and Solid Geometry treated both PARTS I. and II.-PART I., Lines and Angles, Rectilineal Figures. PART III.-Circles (containing the Substance of Euclid, Book III, 1–34, PARTS I, II, and III. 2s. 6d. *.* This volume exactly suits the requirements of the New Syllabus for the King's Scholarship Examination. PART IV.-Squares and Rectangles, Geometrical Equivalents of Certain PARTS III. and IV -Containing the Substance of Euclid, Books II. and 45. 6d. 15. 6d. PARTS IV. and V.-Containing the Substance of Euclid, Book II., PART VI.-Containing the Substance of Euclid, Book XI., 1-21, together PARTS IV., V., and VI, 2s. 6d. MARCH NUMBER NOW READY. SCHOOL WORLD. A MONTHLY MAGAZINE OF EDUCATIONAL WORK AND PROGRESS. The Teaching of Hygiene in Secondary Schools. By C. E. Shelly, M. A., M.D., &c.-The Lighting of School Class-Rooms. By Alan E. Munby, M.A.-Non-Classical Secondary Schools. With an Introduction by Prof. H. E. Armstrong, F.R.S.-Secondary Schools and the Universities. II. The University of Oxford.—Studies in School Management. III. The Supply of Text-books to Secondary Schools. By E. Sharwood Smith, M. A.-The Study of Tennyson's Poems. (Continued.) By Laurie Magnus, M. A.-International Phonetic Association. By de V. Payen Payne.-The Nationalisation of Training Colleges in Scotland.-Experimental Geography. II. Temperature Measurements. (Illustrated.) By A. T. Simmons, B.Sc., and Hugh Richardson, M. A.- Conference on School Hygiene.-Correspondence : The use of Glass Blocks in Refraction. (Illustrated.) By Henry Garrett, B.Sc.-Graph Tracing. By F. C. Boon, B.A. Economics and the Secondary School. By X. Y. Z.-The Teaching of Geography. By Edward King, S.J.—Lanterns for School Use. By Albert Griffiths, D.Sc.-Foreigners as Pupils in English Schools. By A. A. E. Goodall, M.A. PITCH BLENDE (PATENT). Shows a magnificent display of scintillations, showers of sparks, direct from the mineral Pitchblende, Radium, Polonium, Uranium, Thorium, or any radio-active substance, even a Welsbach mantle contains sufficient Thorium to excite the very sensitive screen of the Scintilloscope, which is far more sensitive than the Spinthariscope. The Scintilloscope rivals the most delicate Electroscope as a detector of Alpha rays. The eye sees an inexhaustible shower of stars of white light, giving a very realistic idea of the ceaseless activity of these marvellous substances which are pro- CALCIUM METAL (In round bars ducing the terrific bombardment causing this beautiful display. Radio active supplies of every description, on Sale or Hire. Radium F. HARRISON GLEW, Radiographer (Silver Medallist, Paris, 1900), averaging 4, 8, and 16 oz. each, one inch in diam.), 1/6 per oz. CARBORUNDUM OR SILICIUM CARBIDE (Beautiful show crystals, in lumps of 2 oz. upwards, 2/- per oz.) Rad. Residue, 2/- per tube. Polonium, 21/- per gram; 11/--grair. LIQUID AIR AND LIQUID HYDROGEN. Monasit, 3/- per of Dr. HAMPSON'S AIR-LIQUEFIER is now made to a standard pattern, and numbers are in use in University Laboratories and elsewhere in various countries. The whole apparatus is neat and compact and its parts very easily moved; the Liquefier, without stand, being a cylinder 17 inches high and 8 inches in diameter. It begins to liquefy air in from 6 to 10 minutes after the admission of air at from 150 to 200 atmospheres pressure, making over a litre of liquid per hour. It requires no auxiliary refrigerant and produces a perfectly clear liquid which requires no filtering. The operator has only one gauge to watch and one valve to control. HYDROGEN LIQUEFIER to the designs of Dr. MORRIS W. TRAVERS for use in conjunction with Air-Liquefier. Diamond chips and powder, 10/- per carat (best quality). Bar. Plat. Cyan., for Screens, 3/- gramme, 60/- oz. Crystals, 4/- Radio-active screens, 6d. per square inch. Willemite screens, 6d. per square inch. Electroscopes (special), 21/Spinthariscopes (special), 21/-, 10/6 and 7/6. Selection of Minerals in boxes, 2/6, 5/6, 10/6 and 21/-. New Zealand Vegetable Caterpillar, with a stem showing All Post Free within U.K. Goods may be returned if not approved of, when money will be refunded. GAMBRELL BROS. MANUFACTURERS |
