Ee WEEKLY Heaileus 
Of Nature trusts the mind which 
STRATED JOURNAL OF 
“To the solid ¢ 
SCIENCE. 
yound 
bucks for aye.”—WoORDSWORTH. 
No. 1430, VOL. 55] TP AIUIRES DAW Er 
MARCH 25, 
[RICE SIXPENCE 
Registered as a Newspaper at the General Post Office.] 
(All Rights are Reserved. 
INDUCTION COILS. 
BROWNING’S PLATYSCOPIC LENS. 
APPS! PATENTED INDUCTION COILS are now manufactured | With Larger Angles, Increased Field, and Improved [efinition 
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Ri 
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, FLUORESCENT SCREENS, 68s. and 90s. 
Complete Apparatus for Rontgen ‘‘ X”’ Rays, with Coils 
and Fluorescent Screens, &c. 
HiGkthewway ALITY ONLY. 
Detailed List on Application. 
No Scientific Man 
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FRENA 
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Full particulars 
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R.& J, BECK, Ltd., 68 Cornhill, London, E.C. 
raved Real Size. 
AN ACHROMATIC COMBINATION, 
COMBINING THE DEFINITION OF A MICROSCOPE WITH THE 
PORTABILITY OF A POCKET LENS. 
“If you carry a small Platyscopic Pc ycket Lens (which every observer of 
Nature oug 1 to a o)."—GranTt ALLEN in Kno 
The Platys ns is invaluable to bo 
) uses about three time ar_from the objec 
This allows opaque « ts to be examined 
ens is'made of four degrees-of power, 
J 20, and 30 diams. ; the lowest power, haying 
field, is the best adapted for general use. 
The Lense e set in Ebonite Cells, and mounted in Tortoiseshell Frames. 
Price of the Platyscopic Lens, mounted in Tortotseshell, magni- 
fying etther 10, 15, 20, or 30 déamelers, 18s. 6d. each power. 
Illustrated description sent free. 
nists, mineralog zists, or e 
JOHN BROWNING, 63 STRAND. LONDON, W.C. 
NEGRETTI AND ZAMBRA’S 
BAROGRAPHS AND_THERMOGRAPHS. 
The Baga is fitted in a Mahogany Case with Glass Front, as shown 
above. The Thermograph is mounted in a japanned Metal Case with Glass 
Front, for either indoor or outdoor use. The above give continuous records 
on Charts, which only require changing once a week, and are invaluable to 
invalids and others whoare unable to take daily readings of the ordinary 
instruments. Price of each, with supply of Charts for one year, £6 10s. 
NEGRETTI & ZAMBRA, 
SCIENTIFIC INSTRUMENT MAKERS TO THE QUEEN, 
38 HOLBORN VIADUCT, E.C. 
Briaches—45 CORNHILL, and 122 REGENT STREET- 
