April, 1915. 



KNOWLEDGE. 



WATSON'S 

 MICROSCOPES 



The best obtainable. British-made throughout. 



F.FFIflTF.NT • Enable the worker to get the best out of his 

 *■"■ »v>AAjn x . j nstruinellt- 



CONVENIENT '. Eiery necessary movement is embodied. 



STABLE " With either tripod or horseshoe foot. 



PRACTICAL : Intended fur hard work. 



LAST A LIFETIME. 



The "RESEARCH" Microscope. 



Specification : — 



Mechanical Stage — Giving move- 

 ments 2" X If. Both milled 

 heads on same axis. 



Fine Adjustment — Side limb, 

 vertical lever type. 



Coarse Adjustment — Diagonal 

 rack, long range, enables 

 3" objective to be focussed when 

 on nosepiece. 



Compound Substage — Rack and 

 pinion focussing with centering 

 screws for condenser. 



Movements are slotted and sprung 

 throughout, and wear can be at 

 once compensated. 



Tripod foot giving stability in 

 any position. 



Guaranteed for 5 years. 



Fop the Amateur op Professional this 

 instrument embodies every desirable movement, and 

 ,is at once the cheapest and the best 

 obtainable. 



Prices: — , 



Research Microscope ... 



£12 10 



00. 00. with eyepieces 

 No. 2 and No. 4, objectives 1" and 

 .11 mm. working distance for pond 

 life or blood counts), aplanatised 

 Abbe illuminator with iris diaphragm. 

 In mahogany case 17 17 6 



Full details of the above, and also of 32 Different 

 Models at all prices, will be found in Watson's Micro- 

 scope Catalogue, No, 2 k, which will be forwarded 

 gratis on application. 



APPARATUS FOR:— 



PHOTOMICROGRAPHY. POND LIFE. 



METALLURGY. PETROLOGY. 



BACTERIOLOGY. PROJECTION. 



HEMATOLOGY, &c, &c. 



W. WATSON & SONS, LTD., 



Contractors to fx/ny eovetnments, 

 313 HIGH HOLBORN, LONDON, W.C. 



Branches : 



16 Forrest Road, Edinburgh; I96 Great Portland Strew, London, W. 



Dki-6ts : 



2 Easy Row, llirminiiham; 78 Swanston Street, Melbourne, Australia: 



2I2 Notre Dame Street West, Montreal, Canada. 



Optical Works— HIGH BARNET, HERTS. ESTABLISHED 1837. 



The BECK BINOCULAR 



BECK BINOCULAR MICROSCOPE. 

 No. 1081 P.S. 



(Patent applied for) 



Not only an advance on 

 previous Binoculars, but 

 better tban a Monocular 

 with all powers. 



1. Resolution equal to that 



of a Monocular. 



2. Equal illumination in 



both eyes. 



3. Short tube length, mak- 



ing Microscope com- 

 pact. 



4. No special object- 



glasses or eyepieces 



required. 



5. Standard angle of con- 



vergence. 



6. Stereoscopic vision. 



7. Binocular vision, saving 



eyestrain and giving 

 better results than 

 Monocular vision. 



8. Converted into a Mon- 



ocular by a touch. 



Full descriptive Booklet and Price List on application. 



R. & J. BECK, L td - 68 Cornhill, London, E.C. 



DENTS CLOCKS 



WATCHES AND CHRONOMETERS 



FOR SCIENTIFIC USE. 



Sidereal op Mean Time Clocks for 



Observatories, £21 and upwards. 



THREE GRAND PRIZES 

 and ONE GOLD MEDAL 



ill! FRANCO-BRITISH EXHIBITION. 



The only Grand Prize awarded 

 to a British Firm for Watches, 

 Clocks and Chronometers. 



The only Grand Prize awarded 

 for Astronomical Regulators. 

 Chronographs, and Ship's 

 Compasses. 



TRADE MARK 



61, STRAND, and 4, ROYAL EXCHANGE, LONDON. 



Telephone So. 61 City. 



CAUTION. 



The Proprietors of SCHWEITZER'S 

 "COCOATINA, "FAIRY COCOA," &c, 

 beg to inform their clients that XOXE of their 

 products are manufactured in Germany ; that 

 they are a private E\GLISH COMPANY man- 

 aged by a Board of EXGLISH DIRECTORS; and 

 that all shares are held by relatives and con- 

 nections by marriage of the late sole proprietor. 

 Captain Thomas Edward Symons, R.N. 



