DIARY OF SOCIETIES. LONDON. THURSDAY, MARCH 16. ROYAL SOCIETY, at 4.30.-The Croonian Lecture, on the Position of CHEMICAL SOCIETY, at 8.-Limits of Accuracy of Gold-bullion Assay and ROYAL INSTITUTION, at 3.-The Great Revival-A Study in Mediæval FRIDAY, MARCH 17. ROYAL INSTITUTION, at 9.-Ancient Egyptian Pigments: Dr. William SATURDAY, MARCH 18. ROYAL INSTITUTION, at 3.-Sound and Vibrations: The Right Hon. Lord SUNDAY, MARCH 19. SUNDAY LECTURE SOCIETY, at 4.-An Hour with the Microscope, with Illustrations from Insect Forms (with Oxy-hydrogen Lantern Illustrations): Gerard Smith. MONDAY, MARCH 20. ARISTOTELIAN SOCIETY, at 8.-The Philosophy of Jacob Behmen: C. C. TUESDAY, MARCH 21. ANTHROPOLOGICAL INSTITUTE, at 8.30.-On the Tasmanians as Repre- ROYAL STATISTICAL SOCIETY, at 7.45 (at 28 Jermyn Street, S.W.).- INSTITUTION OF CIVIL ENGINEERS, at 8.-Monthly Reception by the ROVAL INSTITUTION, at 3.-Physical and. Psychical Neurology: Prof. WEDNESDAY, MARCH 22. ROYAL SOCIETY, at 4.30. THURSDAY, MARCH 23. ROVAL INSTITUTION, at 3-The Great Revival-A Study in Mediaæval FRIDAY, MARCH 24. PHYSICAL SOCIETV, at 5.-On the Differential Equation of Electric Flow: INSTITUTION OF CIVIL ENGINEERS, at 7.30.-Some Points in the Regu- ROVAL INSTITUTION, at 9.-Interference Bands and their Applications : SATURDAY, MARCH 25. ROVAL BOTANIC SOCIETY, at 3.45. ROVAL INSTITUTION, at 3.-Sound and Vibrations: The Right Hon. Lord STANLEY Mathematical Instrument Manufacturer to H.M. Government, Council of Mathematical, Drawing, and Surveying Instruments Of the Highest Quality and Finish, at the most Moderate Prices. W. F. S. obtained the only Medal in the Great Exhibition of 1862 for Address:-GREAT TURNSTILE, HOLBORN, LONDON, W.C. WIMSHURST MACHINES. With Glass Plates, all sizes, double and multiple also with Ebonite Cylinders with and without Glass Cases. Batteries, galvanic and medical, Telephones. Galvanometers, pocket, lecture-table and laboratory. School Apparatus of every description. LARGE CATALOGUE, Fifth Edition, Royal 8vo, 144 PP. 700 Illustrations, Post free, 7d. KING, MENDHAM & Co., Western Electrical Works, Bristol. London Address: 12 FENCHURCH STREET, E.C. (W. B. ALLISON, AGENT.) ESTABLISHED 1876. PLATTNER'S COMPLETE BLOWPIPE LABORATORY. For Geologists, Mineralogists, Prospectors, &c. For Quantitative and Qualitative Analysis; comprises Collapsible Glass Case Assay Balance, 74 pieces of Apparatus, 36 Chemicals. The Tools in Polished Mahogany cases, lined with cloth, locks and keys. The complete set contained in a solid black leather travelling case. Very compact, £25 12s. 6d. WILLIAM HUME, I Lothian Street, Edinburgh. TO SCIENCE LECTURERS. See Mr. HUGHES'S PATENT COMBINATION OPTICAL LANTERN, used by late W. LANT CARPENTER, Esq., Prof. FORBES. New Triple constructed for B. J. MALDEN, Esq., this season. New Oxyhydrogen Microscope. Grand Results. Docwra Triple, Prize Medal, Highest Award. Supplied to the Royal Polytechnic Institution, Dr. H. GRATTAN GUINNESS, Madame ADELINA PATTI, &c. Patent Pamphagos Lantern Science Lecture Sets. Novelties Cheapest and Best. Elaborately Illustrated Catalogue 300 pages, 1s.; Postage, 5d. Smaller do., 6d. Pamphlets Free.-HUGHES, SPECIALIST, Brewster House, Mortimer Road, Kingsland, N. ALBERT EDWARD JAMRACH (Late CHARLES JAMRACH), NATURALIST, 180 ST. GEORGE STREET EAST. Implements of Savage Warfare, Idols, Sacred Masks, Peruvian Pottery, Netsukis, China, Lacquer, Gongs, Shells, and other Curios. HARVEY & PEAK, By Appointment to the Royal Institution of Great Britain. 56 CHARING CROSS ROAD, LONDON, W.C. COMBINED AMMETER AND VOLTMETER FOR LABORATORY PURPOSES, Catalogue of 340 Illustrations by post, 6d. With the Assistance of H. W. BATES, F. L.S., F. E. S., &c. DR. D. SHARP, F.Z.S., F.ES A T. R. BILLUPS, F.E.S. London: WEST, NEWMAN. & CO., 54 Hatton Garden. WORTHIES. The following is a list of the Steel Portraits that have appeared in the above Series: MICHAEL FARADAY. THOMAS HENRY HUXLEY. CHARLES DARWIN. JOHN TYNDALL. GEORGE GABRIEL STOKES SIR CHARLES LYELL. SIR CHARLES WHEATSTONE. SIR WYVILLE THOMSON. ROBERT WILHELM BUNSEN. ADOLF ERIK NORDENSKJÖLD. HERMANN L. F. HELMHOLTZ. SIR GEORGE B. AIRY. J. LOUIS R. AGASSIZ. JEAN BAPTISTE ANDRÉ DUMAS. SIR RICHARD OWEN. JAMES CLERK MAXWELL. ARTHUR CAYLEY. SIR C. W. SIEMENS. JOHN COUCH ADAMS. JAMES JOSEPH SYLVESTER. DMITRI IVANOWITSH MENDELEEFF. Proof impressions of these, printed on India paper, may be had from the Publishers, price 5s. each; or the Set 5 OFFICE OF "NATURE," 29 BEDFORD STREET, STRAND. MESSRS. MACMILLAN & CO.'S NEW AND RECENT SCIENTIFIC BOOKS. PROF. BARKER.-PHYSICS: ADVANCED COURSE. By GEO. F. BARKER, Professor of Physics in the University of Pennsylvania. 8vo, 215. NATION:-"The arrangement of subjects treated and the names given them make the work specially noteworthy as an exponent of modern views in physics. While these views are not in themselves new, they here form what we believe is essentially a new classification of the subject for purposes of study and instruction, based on the most recent views of energy considered as being ultimately a phenomenon of the aether.... The work deserves hearty praise for its fulness, its thoroughly modern spirit, its clearness, and a certain freshness in the treatment which adds to its real value as well as to its attractiveness." THE SECOND VOLUME OF PROF. GRAY'S WELL-KNOWN WORK. “I have given, in this second volume," Prof. Gray explains in his Preface, "accounts of experimental investigations in which I have tried to place before the reader, not merely a skeleton of the method followed and the result arrived at, but such a statement in each case as may serve to show the procedure adopted, the difficulties met with, the mode in which they were overcome, the corrections made, and the reduction of the observations to the final result. Thus I have described the researches of Lord Rayleigh, Rowland, J. J. Thomson, and others, on the absolute measurement of currents, the determination of the ohm and of v, the practical methods of testing and measurement devised by Hopkinson, Ayrton, Perry, and other engineers, the magnetic researches of Hopkinson and Ewing, and the discoveries of Hertz in electrical radiation. In all cases it has been my aim, avoiding really unimportant detail, to describe the events of the investigation, and especially the manner in which practical difficulties were met as they arose; for in this way only is it possible I think to learn fully the true lessons of physical experimental science. This plan of proceeding has however rendered the matter, though compressed as far as possible, almost too extensive for a single volume.' FOR ADVANCED STUDENTS IN ELECTRICITY. MR. O. HEAVISIDE-ELECTRICAL PAPERS. By OLIVER HEAVISIDE. 2 vols., 8vo., 30s. net. MANCHESTER GUARDIAN:-"One is struck in looking through these papers by the author's acquaintance with higher mathematics, and the ease with which he introduces and deals with functions like those of Bessel, the properties of which are little known even to mathematicians of high attainments. PROF. HOSKINS.-THE ELEMENTS OF GRAPHIC STATICS. A TextBook for Students of Engineering. By L. M. HOSKINS, Professor of Pure and Applied Mathematics in the Leland Stanford Junior University, formerly Professor of Mechanics in the University of Wisconsin. 8vo, Ios. net. GLASGOW HERALD:-"The definitions are well put, and the whole discussion of the subject is quite satisfactory. . It will be found of great value, both in facilitating the work of the student, and, on account of its consistent notation, in guarding the draughtsman against mistakes." SCOTSMAN:-"The book is clear and explicit. It should serve admirably as an elementary text-book for students of NEW AND ENLARGED EDITION. engineering." MR. D. E. JONES. EXAMPLES IN PHYSICS. By D. E. JONES, B.Sc., late Professor of Physics in the University College of Wales, Aberystwith. Second Edition, Revised and Enlarged. 18mo. 3s. 6d. "The present edition," says the author in the Preface," has been carefully revised, and some sixty pages of additional matter have been added. The examination questions at the ends of the chapters have been replaced by new sets of problems from recent papers.” NEW BOOK BY PROF. OLIVER LODGE. PROF. LODGE.—PIONEERS OF SCIENCE. BY OLIVER LODGE, F.R.S., Extra A course of lectures on the lives of epoch making men, principally in the Department of Astronomy, giving an account of their work, and tracing their influence on the development of human thought. The first part of the course, called "From Dark to Daylight," consists of nine lectures on the men from Copernicus to Newton, especially Tycho, Kepler, Galileo, Descartes, and aims at explaining the scientific aspect of their work in a clear and intelligible manner with copious illustrations. The second part of the course consists of nine lectures on such subjects as the Velocity of Light, Herschel and the Stars, the discoveries of Asteroids and of Neptune, Comets, and Meteors, and the Tides, with some biographical details, and much scientific exposition addressed to persons of literary education. NATIONAL OBSERVER.—"The present work is in marked contrast with most popular science; it is accurate, yet it is gracefully written." NATURE.-" An admirable introduction to the study of astronomy, and no better gift for a beginner could well be chosen ; while to those to whom many of its details are already familiar, the picturesque clearness with which they are presented will make their knowledge more real and more complete. The standard of excellence maintained in the lectures makes distinction difficult and invidious, or we would distinguish the lectures on Newton and those on tides as models of what such popular scientific expositions should be." MACMILLAN AND CO., LONDON. NEW AND INTERESTING MICROSCOPIC OBJECTS. Bacillus Typhi Abdominalis Bacillus of Diphtheria (Loffler) False Membrane from a Child Mildew in Stem of Wheat (Puccinia graminis) Fertile Spike of Chara ... Fungus on Leaf of Potato (Peronospora infestans) Group of 12 different Species of Foraminifera on one Slide, very ... Stem and Petiole of Virginia Creeper, showing defoliation Sieve Tubes in Vegetable Marrow O 3 о O O ... T 6 Type-slide of 400 different Species of Diatoms, the name photo- CLASSIFIED LIST, representing a Stock of 40,000 First-class Objects sent post free on application. MICROSCOPES AND APPARATUS. WATSON & SONS TRIPOD EDINBURGH STUDENT'S MICROSCOPE is suitable for investigations with the highest powers. The quality and W. WATSON & SONS, OPTICIANS TO HER MAJESTY'S GOVERNMENT, COCOA 60 Prize Medals Awarded to the Firm. BE CAREFUL TO ASK FOR FRY'S PURE CONCENTRATED COCOA. PERKEN, SON, AND RAYMENT, MANUFACTURERS. WRITE FOR OUR CATALOGUE. IT IS SENT POST FREE. "OPTIMUS" UBIQUE CAMERA. Printed by RICHARD CLAY AND SONS, LIMITED, at 7 and 8 Bread Street Hill, Queen Victoria Street, in the City of London, and Published b MACMILLAN AND Co., at 29 Bedford Street, London, W.C., and 112 Fourth Avenue, New York.-THURSDAY, March 16, 1893 NATURE A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. NEW CATALOGUE OF LANTERNS AND SLIDES, JUST PUBLISHED, 6d. POST FREE, Contains NEW SETS OF LANTERN SLIDES on HISTOLOGY. (Photo-micrographs.). PROJECTING MICROSCOPES PROJECTING POLARISCOPES, NEWTON & & CO., (RY SPECIAL APPOINTMENT TO THE ROYAL INSTITUTION) 3 FLEET STREET, LONDON. NOW READY.-1s., Post Free. GRIFFIN'S ILLUSTRATED CATALOGUE 16 RED LION ST., CLERKENWELL, LONDON, E.C. Telegraphic Address, Secohm, London. Telephone No. 6770. Ayrton Mather D'Arsonval Galvanometer. ELECTRICAL AND SCIENTIFIC INSTRUMENT MAKERS. PRICED ON APPLICATION. STANDARD. METEOROLOGICAL INSTRUMENTS Now ready, Negretti & Zambra's Encyclopædic Catalogue of Mathematical, Philosophical, Op Royal 8vo, Cloth, Gilt Lettered, price 5s. 6d. NEGRETTI & ZAMBRA, Opticians and Scientific Instrument Makers To Her Majesty the Queen, HOLBORN VIADUCT, 45 CORNHILL, & 122 REGENT STREET, LONDON. PRICE LISTS FREE BY POST TO ALL PARTS OF THE WORI.D. |