™ 
A WEEKEY ILLUSTRATED JOURNAL OF’ SCIENCE. 
“To the solid ground 
Of Necpuak trusts the mind which builds for aye. WORDS WENTR 
No. 2456, VOL. 98] 
THURSDAY, 
NOVEMBER 23, 1916 
Registered as a Newspaper at the General Post Office.] 
[Price SIXPENCE. 
{All Rights Reserved 
X-RAY TUBES 
Of all descriptions Made, 
on the 
Premises. 
: Repaired, & Re-exhausted 
Coolidge Tubes kept in stock. 
NEWTON & WRIGHT, Ltd. 
72 WIGMORE STREET, W. 
Sole Agents for Macalaster Wiggin X-Ray Tubes, 
Undoubtedly the Finest Tubes 
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DUROGLASS L 
14 GROSS STREET, HATTON CARDEN, E.C. 
for all purposes, 
Manufacturers of 
Borosilicate Resistance Glassware. 
_Beakers. 
Soft Soda. Tubing for Lamp Work. 
Flasks, Ete. 
General Chemical and 
Scientific 
Special Glass Apparatus Made to Order. 
DUROCLASS WORKS, WALTHAMSTOW. 
SOLE SELLING AGENTS: 
BAIRD & TATLOCK (LONDON) LTD. 
14 CROSS ST., HATTON GARDEN, E.C. 
Glassware. 
TD. 
REYNOLDS & BRANSON, Ltd. 
Chemical Glassware, Chemical and Physical Apparatus 
Makers to His Majesty's Government (Home and Overseas 
Dominions), Laboratory Outfitters, &c. 
Gold Medals at Allahabad and London. Grand Prix and Gold Medal 
at the International Exhibition, Turin. 
STROUD & RENDELL SCIENCE LANTERN. 
The ** University” Lan- 
tern, with Russan_ iron 
hody, Sliding baseboard, two 
superior, objectives, with rack 
and_ pinion for focnssing,.con- 
densers 4} in. diam., plane 
silvered mirror ‘‘ A,’ which is 
moved by a knob causing the 
rays to be r flected upwards 
for the..projectign of objects 
in a horizontal plane, silvered 
prism whi.h can be-used at 
“C," or as an erecting prism 
in mount ‘ D,” limelight 
burner, slide carrier... .Price 
7 complete in travelling case, 
Without reversible adjustable stage... 3 or ¥ «£11 8°6 
Ditto, ditto, with “* Phoenix” arc lamp .. = 12 18 6 
Reversible scabs stage “ B” for supporting ay atus; 
extra «.. he 5 6 
CATALOGUES (Post free): 
Optical Lanterns and Accessory ‘Apparatus. 
Chemical Apparatus and Chemicals, 44 pages. 
14 COMMERCIAL STREET, LEEDS. 
eer sem es ee 
A New Barograph—THE ‘* JORDAN.” 
(Regd. Design 6287.) 
a 
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. 
