r 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

 Of Nature trusts the mind which builds for aye." — Wordsworth. 



INTENSE" HAND FEED 

 ARC LAMP. 



NEWTON & CO., 72 Wigmore street, London, W. 



WRITE FOR SPECIAL ILLUSTRATED LEAFLET. 



WHEATSTONE'S 



COMPOUND 



GYROSCOPE. 



Accessory parts are also 

 supplied for performing 

 numerous interesting and 

 instructive experiments in 

 the Dynamics of Rotation. 



Price £3 3 O 



MADE BY 



JOHN J. GRIFFIN & SONS, i 



Kemble St. 



KINGS WAY 



TD. 



LONDON, W.C. 



CYLINDROMETER 



(8914) for measuring the curvature of 

 Jenses, provided wilh vernier. It con- 

 sists of a plain rectangular melal plat^- 

 with a rectangular recess of accural- '■ 

 known dimensions cut out of it. i 

 is applied to the surface of a cylind- 1 

 or sphere as shown in the illustration, 

 the distance C D is measured directly 

 by means of small stee! scale, with 

 vernier reading, and the distance A li 

 and C E being known, the radius of 

 the cylinder or sphere can at once be 

 calculated from the lengths of A B 

 and D E by tbe usual application of 

 Euclid III. Stock size. Dimensions 

 of recess, 5 cm. by 5 cm. 



£0 15 6 



(.EXTRACT FROM NEW 

 PHYSICAL LIST.) 



BAIRD & TATLOCK (London), LTD., 



14 Cross Street, Hatton Garden, London, E.C. 



The 



"Public School" 

 Set of 



Meteorological 

 Instruments 



forms 



a simple yn^i^^^im^logical 

 Staticyn ^ a moderatc/yftrke. 



A PaJLhlel dftlCH^^4Jls .3^4 vad %ice 

 List, "\[eleofo!oi;ical fnshumcnis," will 



be s?hl46i! J'^c !.■ ,in<, vUrcs.s. 



NEGREfTl & ZAMBRA 



Holborn Viaduct, London, E.C. ; 

 45 Comhill. E.G.; and 122 Regent Street. W. 



