A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



" To the solid ground 

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



No. i860, Vol. 72] 



Registered .is a Newspaper at the General Post Oflice.] 



Newton's New Demonstrator's 

 "Transpaque" Lantern 



Has all the advantages 

 of our well-known 

 " Demonstrator s 

 Lanterns, and in 

 addition will show 

 brilliantly on the 

 screen, opaque 

 objects or book 

 illustrations, if not 

 larger than a 

 large postcard. 



THURSDAY, JUNE 22, 1905 



[Price Sixpence 



[All Riglils are Reserved. 



pr?! 



NEWTON & CO., 3 FLEET STREET, LONDON. 



PHOTOGRAPHIC LENSES. 



A SIMPLE TREATISE. 

 By CONRAD BECK and HERBERT ANDREWS. 



X -, Post Free 1/3. 



This somewhat difficult subject is made clear without 

 the use of mathematics. 



R. & J. BECK, Ltd., 68 CORNHILL, LOi^DON. 



PRACTICAL NOTES ON 



TELEPHOTOGRAPHY. 



Free on application to 



R. & J. BECK, Ltd., 68 CORUHlll, lOHDON. 



REYNOLDS & BRANSON, L' 



LABORATORY OUTFITTERS and 

 SCIENTIFIC INSTRUMENT MAKERS. 



Enquiries 

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The Watcn Size 

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