A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



•' ro tiu solid groitnii 

 of ,^ ■nine iiiisis the ni^nd whi, It builas ''or aye." — Wouiisunin n. 



No. 165s, Vol. 64]' 



THURSDAY, JULY iS, 1901. 



[Price Sixpence. \ 



Registered as a Newspaper at the General Post Offici.] 



[All Rights are Reserved. 



iivi>xjCTi03xr coir-s. 



APPS' PATENTED INDUCTION COILS are now manufactured 



concurrenily by 



r«j 33 "W T o i^r &j CO., 



Opticians. &c . to H.M. the King. 

 3 r'LEET SM?I«.EET, IL.OJVDOWr. 



\^ 



COMPLETE SETS OF APPARATUS FOR RONTGEN "X" RAYS. 



The Set with lO-in. Spark Coil is being used in many hospitals 



for the Cure of Lupus. 



ILLUSTRATED CATALOGUE POST FREE. 



DEMONSTRATION BALANCE 



FOR 



PHYSICAL 

 EXPERIMENTS. 



Specially designed lo show 

 the principles underlying the 

 construction of the Balance. 



£9:0:0. 



FULL PARTICULARS 

 ON APPLICATION. 



JOHN J.GRIFFIN(& SONS, Ltd., 



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



A NEW 

 LENS 



^WL O/f^ 



yOR ALL 

 WORIC 



In 3 Se 

 I. GEN-ERAL. 

 II. CONVEKTIBLE. 

 III. SEECIAL PROCESS. 



^ 



% 



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



suitable for all work, 



Full Catalogue free on applicaiiou lo the Manufacturers: — 



R. &. J. beck:, Ltd., 



68 CORNHILL, LONDON, E.C. 



NEW PATTERN COMBINED 



BARO- THERMOGRAPH. 



The above iiistrunient Lombiiit.-s in one apparatus the Recording Baro- 

 meter and RecortHng Thermometer, giving thus on one and the same chart 

 continuous records of the atmospheric pressure and temperature for seven 

 days. 



Illnitf.xtcJ frkc lists of ScUnti/ic Instrmiunts ffcc !■}■ /•osl to nil farts 

 o/ttu- 7vorl,i. 



NEGRETTI & ZAWIBRA, 



38 HOLBORN VIADUCT, E.C. 



Branches: 45 CORNH I l.L. .in.l 122 RECENT STREET. 

 AWARDED TWO GOLD MEDALS PARIS EXHIBITION 19C0. 



