THE CAIFFE AUTO-MOTOR (Patented in Britain). NO BRUSHES, NO BANDS, NO INDEPENDENT MOTOR. The interruption cuts the current both for motor and coil. In other words, motor and interrupter are electrically and mechanically linked together. Runs 500 working hours without requiring attention. See NATURE, July 20, 1905, page 277. The leading experts have reported in terms of the highest praise upon this Break after continuous use (vide Testimonials) Price, including box and packing, £4:6: 6 THE MEDICAL SUPPLY ASSOCIATION, 228 Gray's Inn Road, London, W.C. Descriptive Circular upon application. SPINTHARISCOPES. (As devised by Sir WM. CROOKES.) Showing the Scintillations of Radium. Fitted with powerful Lens, and contained in neat Leather Case. The scintillations seen in this instrument are from Pure Radium Bromide of the highest known activity, and are brighter and more plentiful than those produced from Pitchblende or any other radio-active substance. See letter from Prof. Gotch on "The Spinthariscope and Retinal Excitability" (NATURE, June 22, 1905, page 174), setting forth a valuable scientific application of the instrument. Calcium Metal 15/- per lb. 11/3 per oz. Thorianite A. C. COSSOR, 54 Farringdon Road, Awarded Gold and St. Louis Exhibition. WATSON'S MICROSCOPES. 23 DIFFERENT MODELS to select from, suited for every class of research. From £2:26 upwards. Watson's Microscopes are designed to afford the utmost convenience and comfort combined with absolute accuracy for scientific work. They are up-to-date and of highest quality. For full particulars see WATSON'S 1906 CATALOGUE OF MICROSCOPES (188 pages) post free on application. Send for List No. 6, post free on application. W. WATSON & SONS, Opticians to H.M. Government, (Established 1837) 313 HIGH HOLBORN, LONDON, W.C. BRANCHES-16 FORREST ROAD, EDINBURGH, and 2 EASY ROW, BIRMINGHAM. DALLMEYER'S TELE-PHOTO. LENSES & ATTACHMENTS THE CELEBRATED DALLMEYER LENSES. (These Attachments can be fitted to any good Lens.) Printed by RICHARD CLAY AND SONS, LIMITED, at 7 & 8 Bread Street Hill, Queen Victoria Street, in the City of London, and puolished by MACMILLAN AND CO., LIMITED, at St. Martin's Street. London, W.C., and THE MACMILLAN COMPANY, 66 Fifth Avenue, New York.-THURSDAY. May 10, 1956. INDIAN FOREST SERVICE. An Examination will be held by the Civil Service Commissioners on August 28, 1906, for the selection of not less than nineteen candidates for appointment as PROBATIONERS for the INDIAN FOREST SERVICE. Age limits:-18 to 21 years, on January 1, 1906. Subjects of examination :-(1) Mechanics and Physics, (2) Chemistry, and (3) Botany. Period of Probation :-The period of probation will extend over about three years. For the first two years the Probationers will be required to undergo a special course of study at Oxford and to become members of the University if not so already. During the third year of their probation they will receive practical instruction on the Continent. Applications for admission to the examination must be made on a printed form to be obtained (with further particulars, including information as to certain enhanced rates of pay announced March 28, 1906, as to the appointments, &c.) from the SECRETARY, Judicial and Public Department, India Office, Whitehall, London, S. W., and to be returned to him not later than SATURDAY, JUNE 30, 1906. No applications received after that date will be considered. UNIVERSITY OF CAMBRIDGE. LONG VACATION COURSE, 1906. PATHOLOGY, PUBLIC HEALTH AND PHARMACOLOGY. This year the work of the Long Vacation Course will be divided into three sections: (1) (for D.P. H. Students) commencing on Monday, June 25, and (2) (for Junior Students of Medicine) and (3) (for Advanced Students, Medical Men, Veterinary Surgeons, &c.) commencing on Monday, July 2. Any further information may be obtained from Mr. E. E. STUBBINGS, Pathological Laboratory, Medical School, Cambridge. Cambridge, May 4, 1906. ROYAL INSTITUTION OF GREAT BRITAIN. ALBEMARLE STREET, PICCADILLY, W. Professor Sir JAMES DEWAR, M.A., LL.D., D.Sc.. F.R.S., will, on Saturday next, May 19, at Three o'clock, begin a course of Two Lectures on "THE OLD AND THE NEW CHEMISTRY." Subscription to this Course Half-a-Guinea; to all the Courses in the Season, Two Guineas. TELESCOPES.-For sale, new 4" Astronomical Telescope by CookE, jointed body, packed in strong mahogany case. Object glass by TAYLOR of COOKE'S, corrected for photography, 1 star finder, 8 astro. powers, 4 day draws, star diagonals, &c. Oak stands. Photographic camera and all accessories. Also large wood body telescope and reflecting telescope. Full particulars on application NORTHERN POLYTECHNIC INSTITUTE, HOLLOWAY, LONDON, N. (Close to Holloway Stn., G. N. R., and Highbury Stn., N. L.R.) LONDON UNIVERSITY SCIENCE AND ENGINEERING DEGREES. Day and Evening Courses in the above under recognised teachers inMATHEMATICS, PHYSICS, CHEMISTRY, ENGINEERING. Separate Laboratories for Elementary, Advanced and Honours students, exceptionally large and well equipped. RESEARCH. Special arrangements for students undertaking research during vacations. TUITION BY CORRESPONDENCE by an especial unique method for all Examinations in BIOLOGY, BOTANY, CHEMISTRY, GEOLOGY, HUMAN PHYSIOLOGY, HYGIENE, MATERIA MEDICA, PSYCHOLOGY and ZOOLOGY. Writing reduced to a minimum. Work directed. Test Papers corrected and returned. Address Mr. FREDERICK DAVIS, IMPERIAL College, 49 and 51 IMPERIAL BUILDINGS, Ludgate CIRCUS, E.C. COUNTY OF LONDON. The London County Council invites applications for the appointment of an ASSISTANT MISTRESS, specially qualified in Mathematics, Botany, Physics, or Elementary Practical Science, at the Burghley Road Higher Grade Girls' School, Highgate Road, N.W. The Salary will be in accordance with the London County Council scale, particulars of which are set out upon the form of application. Applications should be made on Form 40H.G., to be obtained from the Clerk of the London County Council, Education Offices, Victoria Embank ment, W C., to whom they must be returned not later than 10 a.m. on May 28, 1906, accompanied by copies of three testimonials of recent date. Candidates applying through the post for the form of application should enclose a stamped and addressed envelope. Candidates, other than successful candidates, invited to attend the Committee, will be allowed third-class return railway fare, but no other expenses. Canvassing, either directly or indirectly, will be considered a disqualification. G. L. GOMME, Clerk of the London County Council. Education Offices, Victoria Embankment, W.C. EGYPTIAN GOVERNMENT SCHOOLS. In view of the extension of Secondary Education in Egypt, applications are invited for new ASSISTANT-MASTERSHIPS in Secondary Schools under the Ministry of Education. Masters to begin work in October, in Cairo or Alexandria, and to teach in English exclusively. Over 400 boys in each School, mainly Mohammedans. In the case of two of the Masters now required, the subject mainly essential is Science (Experimental Physics and Chemistry); six of the new Masters will be principally engaged in teaching Mathematics; the others will be concerned more particularly with the teaching of English, including History and Geography. Candidates should be not less than 23 nor over 30 years of age, have a robust constitution, and have taken a University Degree in Honours. They should have experience as Teachers: preference will be given to applicants who hold a Diploma in Teaching. Salary, £295 per annum (Eg.24 per mensem), rising to £393 per annum (Eg.32 per mensem). Allowance for passage out to Egypt. Teaching hours, on an average, four daily, Fridays only excepted. Summer vacation not less than two months. Applications, with full statement of qualifications and accompanied by copies only of testimonials, must be sent in before May 31, 1906, marked outside "Assistant-Masterships," and addressed to H. J. BOVD-CARPENTER, Esq., Senior Inspector, Ministry of Education, Cairo, Egypt, to whom candidates may apply for further information. UNIVERSITY OF BIRMINGHAM. TWO ASSISTANT LECTURESHIPS IN MATHEMATICS. The Council invites applications for the above appointments. Stipends, £175 and £150 per annum, respectively. Applications, accompanied by testimonials, should be sent to the undersigned not later than Tuesday, June 5, 1905. The candidates elected will be required to enter upon their duties on October 1, 1906. Further particulars may be obtained from COUNTY BOROUGH of WATERFORD. TECHNICAL INSTRUCTION COMMITTEE. The Technical Instruction Committee for the County Borough of Water. ford invite applications for the following appointments : Salary () HEADMASTER and ORGANISING SECRETARY. £290, rising by 10 annually to £300. Qualifications must include Theoretical and Practical Chemistry and Physics, and Teaching and Organising experience. Will be required to perform the duties of Organising Secretary and Headmaster of Day and Evening Classes, and to supervise equipping of new Technical School. Duties to be commenced on July 1. 2) MANUAL INSTRUCTOR in Wood and Metal Work. Salary L150, rising by 10 annually to 6180. Qualifications must include Building Trades subjects, Applied Mechanics, Machine Construction and Metal Workshop Practice. Duties to be commenced in September. 10 DOMESTIC ECONOMY INSTRUCTRESS. Salary £80, which all be increased by 10 annually to £120. Certificates in Cookery, Iandry Work, Needlework (including Dressmaking), Housewifery and Hygiene required (1st class in Cookery, and in Laundry Work or Needlework required). Duties to be commenced in September. The candidates appointed will be whole time officers of the Committee, and may be required to give instruction in schools other than the Technical Shouls Applications, stating qualifications, experience, age, and giving references as to character, to be received on or before May 20, 1906, by JAMES J. FEELY, Secretary to Committee. Town Hall, Waterford. May 1, 1906. GOLDSMITHS' COLLEGE, NEW CROSS. DEPARTMENT FOR THE TRAINING OF TEACHERS. About to additional Teachers (Men and Women) will shortly be ap pointed in the above Department. These will include an Assistant Master of Method, an Assistant Mistress af Method (for Infant School Tea hing), and teachers of English Literatare. French, History, Mathematics Elementary Science. The majority of the salaries will be, for Men, between £175 and £250 a year; and, for Women, between £150 and £200 a year; but more or less may be said in exceptional cases. An Assistant Manual Instructor (salary £100 or £120 a year) is also required Applications must be received not later than Saturday, June 2, 1906. Particulars may be obtained from the WARDEN, Goldsmiths' College, New Cross, S E. ROYAL INSTITUTION OF GREAT BRITAIN. ALBEMARLE STREET, PICCADILLY, W. Professor WILLIAM J. SOLLAS, LL.D., D.Sc., F.R.S.,_ will on Toursay next, May 24, at Five o'clock, begin a course of Three Lectures MAN AND THE GLACIAL PERIOD." Subscription to this course, Half-a-Guinea; to all the courses in the Season, Two Guineas. BROWNING'S PLATYSCOPIC LENS. WITH LARGEr angles, increased field, and Engraved Real Size. AN ACHROMATIC COMBINATION. COMBINING THE DEFINITION OF A MICROSCOPE WITH THE PORTABILITY OF A POCKET LENS "If you carry a small Platyscopic Pocket Lens (which every observer of Nature ought to do)."-GRANT ALLEN, in Knowledge. "I have long carried one of these instruments and found it invaluable." JOHN T. CARRINGTON, Editor of Science Gossip. The Platyscopic Lens is invaluable to botanists, mineralogists, or entomologists, as it focuses about three times as far from the object as the Coddington Lens, and has a field unequalled for flatness, allowing opaque objects to be examined easily. It is made in four degrees of power, magnifying respectively 10, 15, 20, and 30 diams. ; the lowest power, having the largest field, is the best adapted for general use. Mounted in Tortoiseshell, magnifying 10, 15, 20, or 30 S. d. diameters, either power... 15 O 17 6 In Nickelised German Silver, either power Combinations of any two powers, in Tortoiseshell Ditto Ditto in Nickelised German Silver ILLUSTRATED DESCRIPTION SENT FREE. OF HASLINGDEN. MUNICIPAL SECONDARY SCHOOL. WANTED, SENIOR MISTRESS, especially qualified in French. Commencing salary, 120, rising by biennial increments of £10 to £160 per annum, with further increments not automatic on special recommendation. ASSISTANT MISTRESS; commencing salary, £100 per annum, rising CITY OF BIRMINGHAM EDUCATION by biennial increments of £10 to £135 per annum, and by further increments COMMITTEE. The Committee requires the services of an ASSISTANT MASTER for the Central Secondary School. Salary, £100 to £160 per annum, according to qualifications and experience. Candidates must be qualified to teach Chemistry Mathematics and Physics desirable. Form of application may be obtained from the undersigned. not automatic on special recommendation. Candidates for either position must be graduates or possess equivalent qualifications. instant. JNO. ARTHUR PALMER, Secretary. Education Department, Edmund Street, May 14, 1906. A RESEARCH FELLOWSHIP in PURE or APPLIED PHYSICS of the value of £125 per annum is offered for award in July next. dates must give evidence of being able to conduct an independent research, state, if possible, the nature of the research they intend to pursue under the direction of the Professor of Physics (Dr. A. Schuster), and give particulars of their previous training and education. Applications should be sent not later than June 20 to the REGISTRAR, from whom details of conditions may be obtained. BOROUGH OF ASTON MANOR Municipal Offices, May 15, 1906. BATTERSEA POLYTECHNIC, BATTERSEA PARK ROAD, S.W. PRINCIPAL-SIDNEY H. WELLS, Wh. Sch., A.M.I.C.E., A.M.I.M.E. GAS ANALYSIS. DYNAMO & MAGNET CARL ZEISS, JENA. MANUFACTURERS should be interested GRASSOT FLUXMETER By its means they can measure directly the flux in their machines or magnets. "A Galvanometer Needle that has to be pushed back to zero, and that stays where it is put by the maxwells, is a curiosity." -See Electrical World for March 24, 1906. ILLUSTRATED PAMPHLET SENT ON APPLICATION. A NEW PATTERN FORTIN'S STANDARD BAROMETER (Registered Design No. 420,297.) As will be seen by the illustration, this Barometer built on original lines. By the absence of the ordinary tubular enclosures (in the usual form of instrument) the mercurial column is FULLY. EXPOSED to view, NO SHADOWS are thrown upon the column, and therefore an extremely accurate and instantaneous reading is made possible. The scales being graduated upon the flat side pieces the DIVISIONS AND FIGURES ARE ALWAYS IN VIEW, and the vernier is very much more legible than in the ordinary tubular patterns. The bore of the tube is 0.5 inch. The scales are graduated in inches and millimetres, and, by means of the verniers, are capable of being sub-divided to read to 0.002 inches and 0.1 m/m. The attached Thermometer on the body of the instru ment is graduated in Fahrenheit and Centigrade scales. It is the BOLDEST Standard Barometer made. The PRICE IS LOWER than that of any other form of Standard Barometer of the same dimensions. It yields readings equally close as the highest priced instruments. Price complete, mounted on handsome Polished Solid Mahogany Board, with Brackets for Suspension, and Opal Glass Reflectors, £7 10s. Od. SMALLER SIZE, "THE STUDENTS," designed for Schools for demonstration work, and small private Observatories; bore 25 reading to '01 inch and 1 millimetre. £3 7s. 6d. Sole Manufacturers and Proprietors of the Regd. Design: PASTORELLI & RAPKIN, Ltd., 46 HATTON GARDEN, LONDON, E.C. ACTUAL MAKERS OF ALL KINDS OF METEOROLOGICAL INSTRUMENTS. Contractors to H. M. Government. Estd. 150 years. Telegrams: "Rapkin, London." Nat. Tel.: 1981 Holborn. N. B.-If any difficulty in securing our Instruments through your Dealer, kindly communicate with us. ILLUSTRATED PRICE LIST POST FREE. |