A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 
“To the solid ground 
Of Nature trusts the mind which builds for aye..—WorpDsWwoRTH. 
No. 2455, VOL., 98]' 
THURSDAY, NOVEMBER 16, 1916 
[ PRICE SIXPENCE. 
Registered as a Newspaper at the General Post Office.] 
{All Rights Reserved 
BUY DIRECT FROM 
F.E.BECKER & CO,BATTON WALL, 
QW1.&0.GEORGE. LTD., succ%?) 
Graphite-Selenium Cells 
FOURNIER D’ALBE’S PATTERN. 
Great Stability and High Efficiency. 
With a sensitive Se surface of 5 sq. cm. anda voygnge 20 the 
additional current obtainable at various illuminations (in 
metre-candles) is :— 
At 1 m.c. ... . 4+ milliamp. 
pgs SR eal 3 
8 re eG “= 
For particulars and prices apply to the SOLE AGENTs : 
John J. Griffin & Sons, 
Makers of Physical and Electrical Apparatus, 
Kemble Street, KINGSWAY, 
LONDON, W.C. 
REYNOLDS & BRANSON, Ltd. 
THE “RYSTOS” LANTERN. 
A Lantern of superior workmanship, fitted with three telescopic draw 
tubes and interchangeable jacket mount, with rack and pinion, for objectives 
of various foci, Will be found to be a most suitable Lantern for use in 
large lecture halls, &c. 
Complete with 
superior objective, 
either 6, 8, 9, or 12 
inckes focus, 
2i-inch diameter, 
condenser 
44-inch diameter, 
and high-power 
limelight burner, in 
travelling case, 
£9 00 
WAR IN THE BALKANS. 
A set of lantern slides from negatives taken by members 
of the Red Cross Missions to Serbia and Montenegro 
for Sale or Hire, 
LIST AND PRICE ON APPLICATION. 
14 COMMERCIAL STREET, LEEDS. 
EER 
A New Barograph—THE ‘‘ JORDAN.” 
(Regd. Design 62871.) 
Shows at a glance the movements of the barometer during 
the preceding days. 
Descriptive Leaflet post free on application to 
NEGRETTI & ZAMBRA, 
38 HOLBORN VIADUCT, E.C.; 
45 CORNBILL, E.C.; 122 REGENT ST., W. 
