y 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid s^rouud 

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



No. 1407, Vol. 54] 



THURSDAY, OCTOBER 15. i! 



[Price Sixpence. 



ReKisiMcd 



Newspapc 



111.: General i'ust OlTicc] 



[AU Rights arc Reserved. 



XRAY FOCUS TUBES. 



1 . icus" Tiibi;s maiuila 



.1 l.y 



NEWTON & CO., 



3 FLEET STREET, LONDON, 



arc slill imrivalled for brilliancy ami definition, and are used by 

 nearly all the leading workers. 



Dr. J. .\lACl.vrvRE, of Glasgow, in NATURE, September lo, 

 says (hat with these Tubes he has obtained "some of the best 

 photographic re.sults in the deeper structures of the body." 



In consequence of the large number of these Tubes which have 

 now been sold, it has been possible to reduce the price to 25s. 

 each. With these Tubes and a 6" Coil and Fluorescent Screen, 

 the beating of the heart and the movements of the diaphragm 

 can be readily seen in an adult. 



Fluorescent Screens, intensely brilliant, 

 8" X 5', 35s. ; to" X S', 63s. 



NALDER BROS. & CO. 



LOND ON. 



N. C. S. 

 THOIWCSOKF 



REFLECTING 

 GALVANOMETER. 



5C00 OH MS' RESISTANCE. 

 VERY SENSITIVE. 



PRICE 



L/ST OF COILS, TUBES, SCA'££NS, &-(. POST FREE. 



JOHN J. GRIFFIN^ SONS, e 



22 GARRICK STREET, LONDON. W.C. 

 nOMPLETE X-RAY APPARATUS. 



FOCUS TUBES. INDUCTION COILS, BATTERIES, 



FLUORESCENT SCREENS, WIMSHURST 



MACHINES, and all PHOTOGRAPHIC REQUISITES. 



OUR TUBES, all of which are well tested and guaranteed before 



;,eiT;- MipplKil. arc divided into lliree classes depending upon the woik 



required to he done, vi/. : — 



A. I-or Photographic Work only, 10s. each 



B For Photographic and Screen Work, 25s. each. 



C. For Photographic an.i Screen Work, exhausted for 



use with Coils giving 6-inch Spark and upwards, 35s. each. 



A and B are for use wilh ^inch and 4-inch Spark Coils. 



INDUCTION COILS, of exccdlenl finish, well tnounted in thoro.^h 

 KlaiM'IF in.ulalion: our o'.i;i .l/nn«/af/l';v, as supplied lo bhe lord 

 Hi 'u.^l '.| M V K.k.S.; y /,.■ /-«'.«■/ .• Prof liurstall, M.A., .ind other.. 



Sitl:, £9; 4-m- £12; 5in-> £15; 6-in., £18. 

 FLUORESCENT SCREENS, of excellent delinition and 

 biiiliancv neatly mounled in ^o.id mahogany fr.ame with handle. _ 



Sizes-5-in.x5.in., 10 6: 7-in. x5-in.,12/6; 8-in. x 6 -m., 15/- 



ANY SI/.K MADtC TO ORDEK. 



DARK BOXES, with Itemovable Screens, from 20s. each. 



Dkmonstratio.ns, and all particulars as to methods of woiking, are 



ijiveii, either verbally or by correspondence, to intending purchasers, i-kee 



ti!t"/'Tfilimmials, &'c.,/row Leading E-xpcrimcntcrs, on a/>fiicalicm. 



Write for CATALOGUES 



Cable Address : 

 SECOHM, LONDON. 



IVo .4aliils ill t.!*..%. 



This instrument delivered Free anywhei-e in U.S.A. 



for -^'eo c.o.u. 



NEGRETTI & ZAMBRA'S 



BINOCULARS AND TELESCOPES. 



of ih.- "OFFICER OF THE WATCH 

 in use on all the vessels of H.M. N: 



■ TELESCOPE, 



£2 2s. 



£2 2s. 



As supplied by NEGRETTI & ZAMBRA to the War OfTice. 



Length, when closed, .. inches. Combining high power and portability. 



NEGRETTI &. ZAMBRA, 



SCIENTIFIC INSTRUMENT MAKERS to the QUEEN 



38 HOLBORN VIADUCT, E.C. 



Branches: 45 CORNHILL; 122 REGENT STREET 



Illustrated Price Lists Free by Post. 



