Current Accounts. 2% Interest allowed on minimum Southampton Buildings, High Holborn, W.C. 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. TO SCIENCE LECTURERS. HUGHES' PHOTO ROTOSCOPE CINEMATOGRAPHS. THE MOST PERFECT. No Flickering. Superb Mechanism. Price £7 7 0. The Moto-Photo Camera for taking the Pictures. Illustrated Lists, 2d. See Mr. HUGHES' PATENT COMBINATION OPTICAL LANTERN, &c. Miniature Triple Lantern constructed for B. J. MALDEN, Esq.; great success. New Oxyhydrogen Microscope. Science Lanterns for Class Demonstration. Magnificent Results. Docwra Triple, Prize Medals, Highest Award. Supplied to the Royal Polytechnic Institution, Dr. H. GRATTAN GUINNESS, &c. Patent Pamphengo Science Lanterns. The Universal Lantern 4-inch Condensers, 4-wick Lamp, Portrait Combination front Lenses, 18s. 6d. Marvellous value. Science Lecture Sets. Novelties. The Lantern Kaleidoscope. Cheapest Lantern Outfits in the World. Grandly Illustrated Catalogue, over 180 choice Engravings, 6d. ; Postage, 4d. Small Illustrated Catalogue, 100 pages, free, 5d. List of 60,000 Slides and 300 Lecture Sets, Science Subjects, Views, &c., 6d. ; Postage, 2d. Pamphlets Free. W. C. HUGHES, SPECIALIST, Brewster House, 82 Mortimer Road, Kingsland, N. SCIENTIFIC WORTHIES. A List of this Series of Steel and ST. MARTIN'S STREET, LONDON, W.C. 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. ROCKS, MINERALS, FOSSILS. For Collectors, Students, Technical Schools, Colleges, &c. COLLECTIONS IN POLISHED DEAL BOXES. 25 Specimens, 5/6; 50 do., 10/6; 1oo 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 NEW CATALOGUE POST FREE. THOMAS D. RUSSELL, 78 Newgate St., London, E.C. ALBERT EDWARD JAMRACH (Late CHARLES JAMRACH), NATURALIST, 180 ST. GEORGE STREET EAST. Implements of Savage Warfare, Idols, Sacred Masks, Peruvian Pottery, Netsukis China, Lacquers, Gongs, Shells, and other Curios. 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 1s. per Tube, Post Free. Helix pomatia, Astacus, Amphioxus, Rana, Anodon, &c., for Dissection purposes. THOMAS BOLTON, 25 BALSALL HEATH ROAD, BIRMINGHAM. MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM. THE LABORATORY, PLYMOUTH. 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. 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. 66 IMPORTANT ANNOUNCEMENT. D'Arsonval's Latest (1904) Apparatus, DISPENSING WITH COILS & INTERRUPTERS. X-RAYS & HIGH-FREQUENCY CURRENTS. (Protected by Numerous Patents.) SILENT IN WORKING. SIMPLE IN MANIPULATION. This apparatus has been already installed by many of the chief workers in Electro-Therapeutics in France and England, THE MEDICAL SUPPLY ASSOCIATION, COUNTRY FAR THE MOST ECONOMICAL SYSTEM KNOWN. where the apparatus may be seen working. HOUSE LIGHTING GAS PLANT. GAS ENGINE AND DYNAMO. Electric Current for 100 16-c.p. lamps can be obtained for ONE PENNYWORTH of fuel per hour by using a CROSSLEY CROSSLEY BROS.. LTD., MANCHESTER. WATSON'S MICROSCOPES & OBJECTS. Watson's New "Club" Microscope. An Instrument of full size of most modern design. Especially arranged for the use of Amateurs. Monocular, £15; Binocular, £18. Watson's well-known Van Heurck and Edinburgh Student's Micro- The Watson-Conrady Condenser System is of new computation, and New Objectives. for the Microscopist. Everything For all the above see WATSON'S 158-page Catalogue of Microscopes, sent Write for Catalogue No. 3 of Micro. Objects, together with newly published supplementary list of Slides, giving details of recently post free. added specimens, post free. (SPINTHARISCOPE for observing the Scintillations of Radium. The very best. Price 21/SPECIALITIES: STRUTT'S RADIUM CLOCK. Price according to quantity and quality of Radium included. RADIUM of MAXIMUM activity in stock, also of medium and moderate activities. Send for particulars. W. WATSON & SONS, 313 HIGH HOLBORN, LONDON, W.C. J. H. DALLMEYER, Ltd., 25 Newman St., LONDON, W. 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. Mar in's Street, London, W.C., and THE MACMILLAN COMPANY, 66 Fifth Avenue, New York,-THURSDAY, Jan. 19, 1905. GLASS BLOWING. Two Courses of Instruction will be given during the Term by Mr. A. C. COSSOR. NEW TERM began MONDAY, JANUARY 9, 1905. The Institute is readily accessible and near to Fenchurch Street, Liver. pool Street, Broad Street and Metropolitan Railway Stations. For details of the Classes apply at the Office of the Institute, or by letter to the PRINCIPAL. W. H. DAVISON, M. A., Clerk to the Governing Body. ROYAL INSTITUTION OF GREAT BRITAIN. ALBEMARLE STREET, PICCADILLY, W. THURSDAY, next, February 2, at Five o'clock, Professor W. SCHLICH, Ph. D., C.I.., F.R.S. First of Two Lectures of Forestry in the British Empire." Half-a-guinea the course. SATURDAY, February 4, at Three o'clock, Sir ALEXANDER C. MACKENZIE, Mus. Doc., D.C.L., LL.D. First of Three Lectures on ** The Bohemian School of Music,' with Musical Illustrations. Half-a-guinea. Subscription to all Courses in the Season. Two Guineas. MUNICIPAL SCHOOL OF TECHNOLOGY, MANCHESTER. Applications are invited for the post of JUNIOR MATHEMATICAL LECTURER. Candidates must be qualified to teach the subjects of the Final B.Sc. of London University in Pure and Applied Mathematics. Salary, £130 per annum. Applications to be forwarded not later than January 30 to J. H. REYNOLDS, Principal. The post of PROFESSOR of PATHOLOGY and BACTERIOLOGY at the School of Medicine, Cairo, is vacant. Pay, Boo per annum, private practice not allowed. Applicants should forward copies of testimonials and such other documents as are mentioned in the printed particulars respecting the post, which may be obtained from the Secretary of the Conjoint Board of England, Examination Hall, Victoria Embankment, London. The latest mail by which applications may be posted will leave London on Friday, February 17. Applications to be addressed to the DIRECTOR, Government School of Medicine, Cairo, Egypt. KING'S COLLEGE. The Council invite applications for the following posts: TO SCIENCE AND MATHEMATICAL MASTERS.-Required immediately (1) Master for Chemistry, Mathematics, and Botany. Salary, 140 to commence. County School (2) Tutor take Mathematics to Army S'a dard Chemistry t Geometrical Drawing. Coaching Establishment, close London. £100 resident. Applications are also invited from Science and Mathematical Masters seeking appointments for after Easter. Early notice assured of all the best vacancies. Address GRIFFITHS, SMITH, POWELL & SMITH, Scholastic Agents (Estd. 1833), 34 Bedford Street, Strand, London. MARINE BIOLOGICAL ASSOCIATION OF THE WEST OF SCOTLAND. DIRECTOR wanted for the Marin Biological Station at Millport Full particulars from JOHN A. TODD, Hon. Secretary, 190 West George Street, Glasgow. Skilled Mechanic (preferably with electrical experience), accustomed to the manufacture of High class Ser unte Instruments. Apply, stating age, experience and salary revured REYNOLDS & BRANSON, Ltd., 14 Commercial Street, Iecďs. For Sale. Very extensive X-ray Installation Comprising Mercury Jet Interruptor, Operating Couch, Localizer Screens, Resistances, Holders, &c. Suit Hospital Price £15 th cluding Wimshurst Machine. --R. MAVER, 18 Gt Marlborough St For Sale.-Volumes of Nature," roughly bound, from November, 1869, to January, 19 5. Apply to Leur-Co C. R. WOODS, R.A.M.C., Royal Innrmary, Dublin GLEW'S SCINTILLOSCOPE PATENT SCREEN PITCHBLENDE SCINTILLOSCOPE (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 producing the terrific bombardment causing this beautiful display. See NATURE, September 29, page 535. Pieces of Pitchblende mineral, ground flat and polished, with Sensitive Radio active supplies of every description, on Sale or Hire. Radium F. HARRISON GLEW, Radiographer (Silver Medallist, Paris, 1900), McCLEAN'S STAR SPECTROSCOPE, For use with a 3-inch or larger Telescope. Double Nose-piece for carrying_above Spectro- CATALOGUES POST FREE. JOHN BROWNING, MANUFACTURING OPTICIAN, 78 STRAND, LONDON, W.C. ALUMINIUM RECTIFIERS. For charging any class of Accumulators, direct from alternating mains. Works on any periodicity or voltage. Action absolutely infallible. No moving parts High efficiency. Requires no attention. Made in Four sizes, to charge FOR PARTICULARS WRITE STEWART, LIVETT & CO., 62 Theobalds Road, London, W.C. (FOUR MINUTES WALK FROM HOLBORN TOWN HALL) COLOUR PHOTOGRAPHY. SANGER-SHEPHERD QUICK CHANGE, ONE PLATE, LATEST PATTERN OUTFITS. EXCELLENT Photographs in Colour are obtained with our smaller lens filter Outfits, complete from 25/-; but for general work, Landscapes in changing light, Portraiture or Photomicrography where rapid exposures in succession are necessary, the Repeating Back with Colour Filters is recommended as the best all round appliance. It may be attached to any, or whole-plate camera or glass plate Kodak, by means of a panel cut to correspond and interchangeable with the ordinary dark slide. This does not in any way interfere with the use of the camera for ordinary work. The three Colour Filters are held in a frame, clipped in front of the double dark slide which carries the two plates, each large enough to record the three negatives side by side, when the slide is pushed past the opening in the outer case. With this Outfit, even a beginner will secure three-colour negatives with the ease and certainty of an ordinary photograph. Repeating Back Attachments, with Filters complete, from 90/Send for New Booklets, post free to readers of Nature," or call and see results obtained by amateurs. SANGER-SHEPHERD & CO., 5, 6, 7 Gray's Inn Passage, Red Lion Street, Holborn, London. |