INDEX NUMBER. 
mo WEEKLY IELEUSRRATED JOURNAL OF SCIENCE. 
4 “To the 
Of Nature trusts the 
solid ground 
mind which builds for aye.’ 
’— WORDSWORTH. 
No. 1415, VOL. 55] 
THURSDAY, DECEMBER To; 
1896. [PRICE ONE SHILLING. 
Registered as a Newspaper at the General Post Office.] 
(All Rights are Reserved. 
INDUCTION COILS. 
Messrs. NEWTON & CO., of 3 Freer Srreer, Lonpon, 
have made an arrangement with Mr. Apps by which the results 
of his unequalled experience in large Coil making have been 
fully placed at their disposal. 
As he has been unable to cope with the demand for these 
instruments, Apps’ Patented Coils are now manufactured con- 
currently by Messrs. Newron & Co. on their own premises. 
These Coils have for many years been acknowledged the best 
and most efficient in the world, and it is hoped that the high 
quality of workmanship maintained in Messrs. NEWTON & Co.’s 
workshops may still further increase their reputation. 
All the Coils up to 10-inch are tested to considerably more 
than the guaranteed length of spark. 
Spark in air. Hos. a Spark in air oy CA 
I in. ees, 0 8 in. (with oillats) = 10 0 
ules mot Peetu to Oo | IO e Bio 2a Ie) 
3» - 12 0 ns en a a 63 0 O 
: >» Pens 0) | 18 7s; 2) {9) 
5 (with pillars) ES 10 oO "Larger sizes Stolerder 
a the above Coils are covered in ebonite, and are of the 
highest quality, and all are fitted with Commutatorand five pairs 
of Terminals so that they can be used with Primary Batteries or 
Accumulators or direct from the main, and the Condenser can be 
cut out if desired, which should be done when using alternate 
currents. 
X-RAY COMPLETE SETS. / 
our own make, Batteries, Focus 
Ser A. Including 3-inch Coil, 
ube, Tube Holder, Barium-Platino-Cyanide Screen, 
Zin. Xx 5 in. £13 0 0 
Ser B. Including 6-inch Coil, Batteries, ‘Larger “Focus Tube, 
Tube Holder, Barium-Platino-Cyanide Screen, gf in. x 7 in. £23 10 0 
BARIUM-PLATINO-CYANIDE SCREENS. 
EXCELLENT FLU ORESCE NCE, in neat Frames with Handles. 
7 in. X 5 im., 21s. ; of in. x 7 in., 325. 6d. ; 11f in. X of in., 555. 
JOHN J. GRIFFIN & SONS, L: 
22 GARRICK STREET, LONDON, W.C. 
NALDER BROS. & CO. 
LONDON. 
N. GC. S. 
THOMSON 
REFLECTING 
GALVANOMETER. 
5000 OHMS RESISTANCE. 
VERY SENSITIVE. 
PRICE 
#9 10 O 
Write for CATALOGUES. 
Cable Address: 
SECOHM, LONDON. 
No Agents in U.S.A. 
This instrument delivered Free anywhere in U.S.A, 
for $60 C.0.D. 
HRISTMAS PRESENTS. 
TRAVELLERS SCIENTIFIC MEI TE 
| Aneroid Barometer ih Aiseade Seales Cae with Patent Dial and 
| Thermometer for Air Temperatures (or a Clinical Thermometer may be 
substituted). 
PRICE £4 10s. to £7 10s. 
“Special” Illustrated Price List of Instruments suitable for 
Presents free by Post to all parts of the World. 
NEGRETTI & ZAMBRA, 
ScrenrTiFic INSTRUMENT MAKERS TO THE QUEEN, 
38 HOLBORN VIADUCT, E.C. 
Branches—45 CORNHILL, and 122 REGENT STREET. 
Teleptone No. 6583. Telegraphic Address: ** Negretti, London.” 
