4 
A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 
“To the solid ground 
Of Nature trusts the mind which budlds for aye.’—WORDSWORTH. 
No. 1560, VOL. 60] 
THURSDAY, SEPTEMBER 21, 1899. 
[PRICE SIXPENCE 
Registered as a Newspaper at the General Post Office.] 
WIRELESS TELECRAPHY. 
“ 
THE APPS-NEWTON” INDUCTION COILS 
made entirely in the London Workshops of 
NEW TON & CoO., 
3S FLEET STREET, E.C., 
are now used by all the principal experts in Wireless 
Telegraphy, as well as in Radiography. 
BEC KH’sS 
NEW 
MICROSCOPE 
THE 
“BRITISH STUDENTS.” 
Microscope Stand No. 55, as 
figured, with Iris Diaphragm, 
One Hye-piece; Double Nose- 
piece, Two Object-glasses, 2/3” 
and 1/6”, adjusted to be in 
about focus, and the whole 
packed in polished Mahogany 
Case, 
£6:8:6 
No. 55. 
R. & J. BECK, Ltd., 
68 CORNHILL, LONDON. E.C, 
| 
With Larger Angles, Increased Field, and Improved Definition 
| Engraved Real Size. 
| AN ACHROMATIC COMBINATION, 
| COMBINING THE DEFINITION OF A MICROSCOPE WITH THE 
| PORTABILITY OF A POCKET LENS. 
| _ ‘If you carry a small Platyscopic Pocket Lens (which every observer of 
| Nature ought to do)."—GraANT ALLEN in Knowledge. ; 
The Platyscopic Lens is invaluable to botanists, mineralogists, or ento 
| mologists, as it focuses about three times as far from the object as the 
Coddington Lenses. This allows opaque objects to be examined easily. 
The Platyscopic Lens is made of four degrees of power, magnifying 
respectively 10, 15, 20, and 30 diams. ; the lowest power, having the largest 
field, is the best adapted for general use. 
The Lenses are set in Ebonite Cells, and mounted in Tortoiseshell Frames. 
Price of the Platyscopic Lens, mounted in To rtotseshell, magnifying either 
10, 15, 20, 0” 30 diameters, each power, 15s. 
In nichelised German Silver, each power, 178. 6d. 
Illustrated Description sent free. 
JOHN BROWNING, 63 STRAND, LONDON, W.C. 
NEGRETTI & ZAMBRA’S 
TRAVELLER'S? SCIENTIFIC ‘COMPANION. 
Consisting of Aneroid Barometer with Altitude Scale, Compass with Patent 
Dial and Thermometer for Air Temperatures (or a Clinical Thermometer 
may be substituted). 
PRICE £4 10s. to. £7 10s. 
Can also be had Mounted in Gold and Silver Cases 
Useful Present for Gentlemen visiting the Colonies and Officers on 
Foreign Service. 
NEGRETTI & ZAMERA, 
ScIENTIFIC INSTRUMENT MAKERS TO THR QUEEN, 
38 HOLBORN VIADUCT, E.C. 
Brancues—4s5 CORNHILL; 122 REGENT STREET 
