A WEEKLY ILLUSTRATED JOURNAL OE SCIENCE. 



' ' To the solid ground 

 Of Nature trusts the viind which builds for aye." — Wordswor'LH. 



Xo. 1645, Vol. 64] 



THURSDAY, MAY 9, 1901. 



Registered as a Newspaper at the General PcPt Ofi^.ce.] 



WIRELESS TELEGRAPHY. 



THE ""APPS-NEWTON" INDUCTION COILS, 



made entirely in the LondoniWorkshops of 

 P«TE-W"TO]Nr SC CO., 



3 r-x-EET st:?i2,eet, e.g., 



r~ are now used by all the principal Military, Naval, and 

 Commercial Experts in Wireless Telegraphy, as well as in 

 Radiography. 



L-A-ItG-E 



DEMONSTRATION BALANCE 



^1 ^ 1 x-^N PHYSICAL 

 i \^ % ^( \ EXPERIMENTS. 



Specially designed to 

 show the principles under- 

 lyint; the construction of 

 tlie Balance. 



£7:7:0 



FULL PARTICULARS CN 

 APPLICATION. 



JOHN J. GRIFFIN & SONS, l^ 



20-26 SARDINIA ST., LINCOLN'S INN. W.C. 



A NEW 



LENS 



[Price Sixpence. 



[All Rights are _ Reserved. 



FOR ALL 

 WORK. 



^m\i Off 



.7^ U 3 Sbr.es. 05^ 



^^ 11. CO.\Vh.RTIBLE. (tj^ 



^^ HI. SEECIAL PROCESS. \^i 



**' miIiJi,;i;:;::::::^;::;iiiJ3|f^ ^ 



This rapid, wide, medium or narrow angle lens all in one is 



suitable for all work 



Full Catakis;ne free on application m tlie Maiuifacltirers : — 



R. & J. BECK, Lta., 



68 CORNHILL, LONDON, E.C. ' 



NEGRETTI & ZAMBRA'S 



IMPROVED 



SELF-RECORDING RAIN- 

 GAUGES, BAROMETERS & 

 THERMOIVIETERS, 



Giving contiuuous Records 



on Charts which only require 



changing weekly, 



Invaluable to Invalids and 



others unable to take daily 



readings. 



Illustrated Price List of Instruments free by Post to all 

 parts of the World. 



NEGRETTI & ZAKIBR^ 

 38 HOLBORN VIADUCT, E.Q.' 



Bkakchfs : 4; CORNHILL. and i25 REGEXT^STKEET. '^ 



AWARDED TWO GOLD MEDALS PARIS EXHIBITION 19Q0.> <. QQ' 



