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°A\ WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 
“To the solid ground 
Of Nature trusts the mind which ‘builds for aye."—WorRDSWORTH. 
No. 2469, VoL! 98}. 
THURSDAY,.FEBRUARY 22, 1917 
[PRICE SIXPENCE. _ 
Registered 'as a Newspaper -at the Géneral Post Office.) 
[All Rights Reserved. 
BUY DIRECT FROM 
F.E.BECKER & CO,#ATTON WALL, 
LONDON, E.C. 
(W.&J.GEORGE. LTD.,SUCC 4?) 
Graphite-Selenium Cells 
FOURNIER D’ALBE’S PATTERN. 
Great Stability and High Efficiency. 
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At 1m... ... } millilamp. 
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At 500 ,, 2 ” 
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. 
Chemical Glassware, Chemical and Physical Apparatus 
Makers to His Majesty's Government (Home and Overseas 
Dominions), Laboratory Outfitters, &c. - 
Gold Medals Allahabad, London, Turin. Grand Prix, Turin. 
STROUD & RENDELL SCIENCE LANTERN. 
The ‘* University ’’ Lan- 
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superior objectives, with rack 
and pinion for focussing, con- 
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silvered mirror ‘‘ A,” which is 
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A New Barograph—tTHE “* 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 CORNHBILL, E.C.; 122 REGENT ST., W. 
ion 
| Mus 
—_ 
<ansonian Inseam 
i tig, 
MAR 12 i9i/ 
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