ENGINEERING AND CHEMISTRY. CITY AND GUILDS OF LONDON INSTITUTE. SESSION 1909-1910. The COURSES of INSTRUCTION at the Institute's Central Technical College (Exhibition Road) are for Students not under 16 years of age: those at the Institute's Technical College, Finsbury, for Students not under 14 years of age. The ENTRANCE EXAMINATIONS to both Colleges are held in September, and the Sessions commence in October. Particulars of the Entrance Examinations, Scholarships, Fees, and Courses of Study, may be obtained from the respective Colleges, or from the Head Office of the Institute, Gresham College, Basinghall Street, E.C. CITY AND GUILDS CENTRAL TECHNICAL COLLEGE. A College for Higher Technical Instruction for Day Students not under 16 preparing to become Civil, Mechanical, or Electrical Engineers, Chemical and other Manufacturers, and Teachers. The College is a "School of the University of London," and also forms the Engineering Section of the Imperial College of Science and Technology. Fee for a full Associateship Course, £36 per Session. R. MELDOLA, F.R.S., F.I.C. JOHN WATNEY, Hon. Secretary. City and Guilds of London Institute, AËRIAL NAVIGATION.-Mr. Eric Stuart BRUCE, M.A. Oxon., F. R. Met. Scc., Member of Council and late Honorary Secretary Aeronautical Society of Great Britain, VicePresident Aërial League of the British Empire, Membre d'Honneur Aéro Club of France, can accept engagements for his eminently suc cessful lecture, "AIRSHIPS, BALLOONS, AND FLYING MACHINES,' profusely illustrated by elaborate experiments and working models, also for shorter demonstrations at Soirées, Exhibitions, &c. Now booking for Winter Season. For prospectus, terms, &c., address E. S. BRUCE, Esq., Airth, Sunningdale, Ascot. HARTLEY UNIVERSITY COLLEGE, Principal-S. W. RICHARDSON, D.Sc. (Lond.), M. A. (Camb.). PRIFYSGOL CYMRU. UNIVERSITY OF WALES. TWO PRICE DAVIES SCHOLARSHIPS to the University of Wales, each of the value of £30 per annum, and tenable for three years at either the University College of Wales, Aberystwyth, or the University College of North Wales, Bangor, will be awarded in September, 1909. Particulars may be obtained from the REGISTRAR, The University Registry, Cathays Park, Cardiff. COUNTY BOROUGH of SUNDERLAND. THE TECHNICAL COLLEGE. Principal-V. A. MUNDELLA, M.A., B.Sc., M. I. E. E. Applications are invited for the vacant position of ASSISTANT LECTURER and DEMONSTRATOR in the CHEMISTRY DEPART. MENT, salary beginning at £120 per annum. Applications must be returned by July 13 to the undersigned, from whom further details of the appointment may be obtained. PORTSMOUTH EDUCATION COMMITTEE. (HIGHER EDUCATION.) GIRLS' SECONDARY SCHOOL. APPLICATIONS ARE INVITED FOR THE POST of SEX SCIENCE MISTRESS. Graduate, with good experience, to teach Physics, Chemistry, Botany London Matriculation and Senior Oxford Standard. Ability to th little Geography on modern lines a recommendation, but not an esse Salary, 135, increasing after approved service to £150 by £5 increments. Particulars should be given in the following order, viz., Name, Adén Age, Training, Qualifications, Previous Experience, Present Appointme Applications, on paper of foolscap size, accompanied by copies three recent testimonials, should be received not later than the 17th. addressed to the SECRETARY, at the Municipal College, Portsmouth. SCIENCE MASTERS required in Se tember, (a) for first-grade Public School, good degree and expe essential. Salary from £160; if able to take highest Mathem not less than £200, increasing. D 19289. (b) Graduate with exper to teach Science, with Mathematics or French, in Public Seur School. 160 or £170, non. res., increasing. No. D 20360. ( Endowed School, to teach Chemistry and Botany, 160, non D 20260. (d) Experienced Science Graduate to teach Botany, mistry and Physics, and Mathematics. Dual School. £140, Don and extras. No. D 20242. (e) To teach Mathematics and Sc in Proprietary School; good Degree and experience esser Salary up to £150, res. D 20063. MATHEMATICAL MASTERS require in September, (a) for Public Secondary School; Mathematical H Degree and experience necessary. Non-res., 160. D 19320. High-class Preparatory School; res., up to 130. D 19850 f Public School, Oxford or Cambridge Mathematical Honour D and experience. Res., 130 to £150. D 19957. (d) Oxford s bridge Mathematical Honour man for Public Secondary School i up to £140, increasing. D 19879. For further details of these and other vacancies apply, with part of qualifications, to Messrs. TRUMAN & KNIGHTLEY, Ltd., Edua Agents, Sheffield House, 158-162 Oxford Street, London, W. THE UNIVERSITY OF SHEFFIELD APPOINTMENT OF ASSISTANT LECTURER AND DEMONSTRATOR IN BOTANY. The Council are about to appoint an ASSISTANT LECTURER: DEMONSTRATOR in BOTANY. Applications should be made to the undersigned, from whom particulars may be obtained. W. M. GIBBONS, Regist THE UNIVERSITY OF SHEFFIELD The Council are about to appoint an ASSISTANT LECTURE Lea Wanted, a Director of Education for the Go BATTERSEA POLYTECHNIC, The Governing Body require the services of the following for Eve Classes : TEACHER of GEOLOGY and TEACHER of PHYSIOLOGY For particulars send addressed envelope to the SECRETARY. reece.-Required, a Master to teach the English language and all branches concerning the study of Navigation. Salary, £14 a month, non-res. Good school. Address -GRIFFITHS, SMITH, POWELL AND SMITH, Tutorial Agents (Estd. 1833), 34 Bedford St., Strand. o Science Masters.-Required in September, (1) Graduate to teach Botany, Chemistry, and Physics from an agricultural point of view, and Mathematics. Salary, 130 to £140, non-resident. (2) Graduate for Chemistry and Physics. Salary, £130, non-resident. Grammar School. Address-GRIFFITHS, SMITH, POWELL AND SMITH, Tutorial Agents (Estd. 1833), 34 Bedford St., Strand. VANTED: RADIUM.-Armbrecht, Nelson & Co., 71 and 73 Duke Street, Grosvenor Square, London, W. MOSQUITOES, GNATS and FLIES will not attack if a little of Ambrecht's Pyrethrum is put on the skin. It protects for about 12 hours, and also cures stings of any insects-wasps and bees included. Price 2s. 9d. post free U.K.; Germany, Holland and English Colonies 15., France and Italy 1s. 6d., extra.-Armbrecht, Nelson & Co., 71 and 73 Duke Street, Grosvenor Square, London, W. GLASS BLOWING. ALL KINDS OF SCIENTIFIC AND EXPERIMENTAL GLASS BLOWING H. HELM, 66 HATTON GARDEN, LONDON, Telephone: 212 Holborn. ACTUAL MAKER of ALL KINDS of X Ray, Geissler and other Vacuum W. G. PYE & CO., Scientific Instrument Makers, GRANTA WORKS, CAMBRIDGE, ENGLAND. The OLD PLATINUM, GOLD PERFECT' Scrap, &c., valued or purchased. SPINK & SON, Ltd., O CORNHILL, E.C., & 17 & 18 PICCADILLY, LONDON, W. 201 MERCK'S REAGENTS & CHEMICALS For ANALYTICAL, MICROSCOPIC, BACTERIOLOGICAL and STANDARDS OF PURITY, RELIABILITY AND To be had through the regular Trade Channels, or E. MERCK, 16 Jewry St., LONDON, E.C. Head Office and Works: DARMSTADT. JAS. SWIFT & SON, Manufacturing Opticians to H.M. Government. NEW RESEARCH WITH VERY COMPLETE MECHANICAL MOVEMENTS. Price, fitted with Triple Dustproof Nosepiece, Abbe Condenser with Iris Diaphragm, Two Oculars, Three Objectives: in., in., and in. Oil Immersion, in Cabinet, £21. 1 BELMONT ST., CHALK FARM, LONDON, N.W CAMBRIDGE UNIVERSITY Darwin and Modern Science. Es says in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of "The Origin of Species." Edited by A. C. SEWARD, Professor of Botany in the University of Cambridge. A symposium of twenty-eight essays by English and foreign experts-every name being that of a recognised authority in that subject with which he deals. It is no exaggeration to speak of this work as monumental ... for the future historian of science it must for all time serve as a landmark indicating the present stage of development of scientific doctrine in every department of human thought where science holds sway, and where the great principle of evolution has, under Darwin's influence, served as a guide in the interpretation of organic and inorganic nature." -Nature Royal 8vo with 2 portraits and 3 plates 18s net The Foundations of the Origin of Species. Demy 8vo 1 portrait 1 plate 7s 6d net The first of the two essays here printed under the title The Foundations of the Origin of Species was written by Charles Darwin in June, 1842, but the manuscript only came to light in 1896, when it was found among his papers. Although written, seventeen years before the publication of The Origin of Species, as a brief abstract only of his theory, it is remarkable that it gave in about thirty-five pages so full an outline of his future work. It was enlarged during the summer of 1844 into one of two hundred and thirty pages, which constitutes the second essay in the book. The essays are preceded by a full introduction by his son, Francis Darwin, and the volume contains also a portrait of Charles Darwin taken in 1854, and a facsimile of a paragraph in the manuscript of 1842 PRESS Agriculture in the Tropics. An elementary treatise by J. C. WILLIS, M. A., Sc. D., Director of the Royal Botanic Gardens, Ceylon: Organising Vice-President Ceylon Agricultural Society; Editor of "The Tropical Agriculturist." Demy 8vo Trees. There being no general work on tropical agriculture other than those dealing with the technical side of the subject, the author has endeavoured to supply this want in the present work and to place before the public something of the underlying political and theoretical aspect of the question, setting forth what such agriculture really is, the conditions under which it is carried on, its successes and disasters and their causes, the great revolution that is being effected by western influences, and other general principles underlying the whole subject. He considers it of great importance, in view of the fact that the cooler countries will come to depend more and more upon the warmer zones, that the peoples of the north should understand the general position with regard to agriculture in the tropics. By the late H. MARSHALL WARD, Sc.D., F.R.S. Vol. V, FORM AND HABIT, with an appendix on seedlings. Charles Darwin as Geologist. The Palæontology Rede Lecture given at the Darwin Centennial Commemoration on Crown 8vo 2s net "Darwin began his scientific career as a geologist, and in this lecture Sir Archibald Geikie makes acknowledgment of the services he has rendered to the science. The views expressed in the geological chapters of The Origin of Species will be found by posterity, he thinks, 'to mark a notable epoch in modern geology." "-Observer HENRY WOODS, M.A., University Lecturer in Palæozoology, Crown 8vo The general plan of this work is to give, in each group of the Invertebrata, a short account of its general zoological features, its classification and the characters of the important genera, and a description of the present distribution and the geological range. Some new figures have been added in this edition, and the work has been revised throughout. London, Fetter Lane: Cambridge University Press: C. F. CLAY, Manager "The Improvement of Power Factor in Alternating-Current Systems." (With discussion.) By Miles Walker. "Early Experiments in Electric Traction." By W. W. Lackie. "The Electro-Hydraulic Pumping Plant at the Bristol Docks." (With discussion.) By W. A. Clatworthy. "Researches on the Magnetic Properties of a Series of Carbon Tungsten Steels." (With discussion.) By T. Swinden. "The Responsibility of the Engineer." By J. S. Highfield. "The Measurement of the Insulation Resistance of a Live Three-Wire System." By Dr. G. Kapp and Dr. J. D. Coales. "Experimental Analysis of Armature Reaction." By Dr. G. Kapp. Messrs. E. & F. N. SPON, Ltd., 57 Haymarket, S. W. S HARLING'S SLIDE RULES FOR CIENTIFIC AND W. H. HARLING'S Standard Pattern CAL CULATING RULE in Mahogany with celluloid face, inproved construction, with aluminium and glass curvor. Size 10 ins., in case, with instructions, 10s. 6d. W. H. HARLING'S "Cubing" RULE (as figured, with which everything can be done that the Standart Rule will do, and, in addition. Cube, Cube Root, and Logarithms by inspection only, also 5th Powers, and Roots. Size 10 ins, in case, with instructions, 12s. 6d. STUDENT'S CARDBOARD SLIDE RULE, with metal cursor, 5-inch size, in paper case, with instructions, 18. Do., do., 10-inch size, in case, with instructions, 2 ALL MAKES OF SLIDE RULES SUPPLIED FROM STOCK. LIST OF SLIDE RULES (excerpt from Full Catalogue) post free. W. H. HARLING, Mathematical, Drawing, & Surveying 47 Finsbury Pavement, London, E.C.; and at Grosvenor Works, Hackney. Instrument Manufacturer, LIQUID AIR AND LIQUID HYDROGEN. 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. For prices and particulars of the above and commercial apparatus of the same description manufactured under the Lindo and Hampson patents apply to THE BRITISH OXYGEN CO., Ltd., (Formerly Brin's Oxygen Co., Ltd.) ELVERTON STREET, WESTMINSTER, S.W. SECOND-HAND MICROSCOPES, &c. Second-hand Microscopes and Apparatus by Zeiss, Leitz, Ross, R. & J. Beck, Swift & Son and Watson & Sons ; the largest selecte in London. Price List post free on application. Also Second-hand Telescopes, Prism and other Field Glasses and Mathematical Instruments by all the leading makers. Price Lis post free on application. MILLIKIN & LAWLEY, 165 Strand, London, W.C. Sales by Auction. SALES OF MISCELLANEOUS PROPERTY. MR. J. C. STEVENS begs to announce that SALES are held EVERY FRIDAY, at his Rooms, 38 King Street, Covent Garden, London, W.C., for the disposal of MICRO SCOPES, SLIDES, and OBJECTIVES-Telescopes-TheodolitesLevels-Electrical and Scientific Instruments-Cameras, Lenses, and all kinds of Photographic Apparatus-Optical Lanterns with Slides and all Accessories in great variety by Best Makers-Household F niture-Jewellery-and other Miscellaneous Property. On view Thursday 1.30 to 5.30 and morning of Sale. NATURE POPULAR Crown 8vo. SERIES. Crown 8vo. LECTURES and AD- TIMBER, and some of its DISEASES. |