A WEEKLY ILLUSTRATED JOURNAL’ OF. SCIENGE. 
“To the solid ground hy 
Of Nature trusts the mind which ouilds for aye.’’—WoORDSWoRTII. ; 
Gi prais ida el 
—~Onal Museve 
No. 2230, VOL. 89] 
Registered as a Newspaper at the General Post Office.) 
NEWTON & CO.’S 
“DEMONSTRATOR’S’ LANTERN 
FOR ELECTRIC OR LIMELIGHT 
With Prism for Erecting, 
and for Vertical Projection. 
Price £10 10s. 
72 WIGMORE ST., 
LONDON, w. 
Established over 200 Years 
The most 
simple and 
efficient 
Single 
Lantern 
yet 
constructed 
for general 
scientifie 
By Post 
1/3 
It is the Key to Success in Photography. 
Who can expect to excel who does not understand 
how to use the diaphragm, the swing back, the 
rising front, focussing scale, &c., &c.? All such 
questions are lucidly and simply explained in 
“PHOTOGRAPHIC LENSES : 
A SIMPLE TREATISE.” 
350 pages, 44 plates, numerous diagrams and 
illustrations, cloth bound. 
R. & J. BECK, Ltd., 8, CORNHILL. 
*9 London, E.C. 
THURSDAY, JULY 25, 1912, 
[PRICE SIXPENCE 
z  [AllU Rights Reserved. 
REYNOLDS & BRANSON, Ltd., 
Chemical and Scientific Instrument Makers to His Majesty’s 
Government (Indian, Home, and Colonial), Laboratory 
Furnishers and Manufacturing Chemists. 
d The “RYSTOS* 
CONDUIT DEVELOPING 
TANK. 
(REGD.) 
For use when developing 
photographic plates by the Time 
or Stand Method, with conduit 
for circulating the developer by 
inclining the tank at intervals, 
thus preventing uneven develop- 
===|| ment. With light-tight lid and 
5 =@ removable rack. 
rice in Copper Price tn Ger. Sid. 
To hold 6 or 12 9/- . UI) 
_ Plates back to back. | 
<q Ine Do. at 3/6 11/6 |_Post 
< 3h in. Do. 96 11/6 | Free. 
- X 4}in. Do. 11/- 136 | 
x 64 in. Do. 16/6 21/- 
‘Other siz:s at proportionate prices. 
New Catalogue, 104 pages, post free on application. 
14 COMMERCIAL STREET, LEEDS. 
NEGRETTI & ZAMBRA’S 
Anemo-Biagraph 
records the velocity of the wind ; 
The Wind-Direction Recorder 
registers the direction; and the 
Combined Apparatus 
records both velocity and _ direction 
simultaneously upon the one chart! 
Full particulars sent 
free on request. 
38 Holborn Viaduct, London, E.C. 
Branches : 
45 Cornhill, E.C.; & 122 Regent St., W. 
