/« I' 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

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



INDUCTION COILS, i NALDER BROS. & CO.. 



rs. NEWTON & CO., of 3 Fleet Street, London, 

 made ai< arrangement with Mr. Apps by which the results 

 ; unequalled experience in large Coil inaking have been 

 placed at their disposal. 



he has been unable to cope with the demand for these 

 ments, Apps' Patented Coils are now manufactured con- 

 itly by Messrs. Newiox & Co. on their own premises. 

 ;se Coils have for many years been acknowledged the best 

 Host efficient in the world, and it is hoped that the high 

 y of workmanship maintained in Messrs. Newton & Co.'s 

 hops may still further increase their reputation. 

 the Coils up to lo-inch are tested to considerably more 

 the guaranteed length of spark. 



; in air. £ s. ,/. 



1. (with pillars) 27 10 o 

 .. 36 15 o 

 ,, ,, 63 o o 

 ,, . ., 75 o o 

 Larger sizes to order. 

 the above Coils are covered in ebonite, and are of the 

 ;t quality, and all are fitted with Commutator and five pairs 

 rminals so that they can be used with Primary Batteries or 

 nulators or direct from the main, and the Condenser can be 

 It if desired, which should be done when using alternate 



HN J. GRIFFIN & SONS, l^ 



; GARRICK STREET, LONDON, W.C. 

 OMPLETE X-RAY APPARATUS. 



JS TUBES. INDUCTION COILS. BATTERIES, 

 FLUORESCENT SCREENS. WIMSHURST 

 HINES, and all PHOTOGRAPHIC REQUISITES. 



R TUBES, all of which .are well tested and guaranteed before 

 ■np[/i .1, ;ire divided into three classes depending upon the work 



■r Photographic Work only, lOS. each. 



•r Photographic and Screen Work, 25s. each. 

 ■I Photographic ami Screen Work, exhausted for 



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



1(1 B are for use with 3-inch and 4-inch Spark Coils. 

 . CTCTION COIIiS. ..f excellent finish, well m.n.nted in thorough 

 "'TK insulation; (?«?- irvn Manufacture, ss supplied to Sheiford 

 Ks<i., .M.A., F.R.S.; '/ /„• I.amet ; Prof Hurstall, M..\., .and others. 



in., £9; 4-in., £12; 5-in., £15; 6-in., £18. 



VORBSCBNT SCREENS, of excellent definition and 

 ■y. neatly mounted in ;io. .d mahogany frame w-ilh handle. 

 -5-in. V 5. in., 10/6 ; 7-in. x 5-in., 12 6 ; 8-in. x 6-in., 15/- 



DARK BOXKS, with Removable Sere 

 oNSTKATioNs. .-uid .til particulars a-s 

 either verbally or hy correspondence, to 



IS, from 20s. each. 



methods of working, ai 

 ntending purchasers, fre 



LONDON. 



D'ARSONVAL GALVANOMETER 



Delivered Free anywhere in U.S.A. for -^32 C.O.D. 

 Oj5r^ -Write for 



CATALOGUES. 



D'ARSONVAL 

 GALVANOIVIETER 



,As illustvaterl). 



VERY PORTABLE 

 SENSITIVE. 

 IN STOCK. 



£5J) O 



!^ NO AGENTS 



a/s, &*c.,/r0t/i Leading Experivtenters 



NEGRETTI & ZAMBRA'S 



BINOCULARS AND TELESCOPES. 



M.ikers of the "OFFICER OF THE WATCH" TELESCOPE, 

 in use on all the vessels of H.M. Navy. 



£2 2s 



£2 2s. 



As supplied by NEGRETTI & ZAMBRA to the War Office. 



Length, when closed, 11 inches. Combining hish power and portal.i 



ity. 



NEGRETTI & ZAMBRA, 



SCIENTIFIC INSTRUMENT MAKERS to the QUEEN, 



38 HOLBORN VIADUCT, E.G. 



Branches: 45 CORNHILL; 122 REGENT STREET. 

 Illustrateu Price Lists Fuhe iiv Post. 



