b Sa “ ian i WStity nt 
A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE, 
; ; “To the solid ground 
Of Nature trusts the mind which builds for aye."—WorDsWoRTH. 
_ No. 2452, VoL. 98] 
THURSDAY, OCTOBER 26, 1916 
[PRICE SIXPENCE. 
Registered as a Newspaper at the General Post. Office.] 
{All Rights Reserved. 
X-RAY TUBES 
Of all descriptions Made, 
Repaired, & Re-exhausted. 
on the Premises. 
Coolidge Tubes kept in stock. 
NEWTON & WRIGHT, Ltd. 
72 WIGMORE STREET, W. 
- Sole Agents for Macalaster Wiggin X-Ray Tubes, 
Undoubtedly the Finest Tubes 
in the World for all purposes, 
TD. 
DUROGLASS L 
14 GROSS STREET, HATTON GARDEN, E.C. 
Manufacturers of ; 
Borosilicate Resistance Glassware. 
Beakers. Flasks, Ete. 
Soft Soda Tubing for Lamp Work. 
General Chemical and 
Scientific Glassware. 
Special Glass A. pparatus Made to Order. 
DUROCLASS WORKS, WALTHAMSTOW. 
SOLE SELLING AGENTS: 
BAIRD & TATLOCK (LONDON) LTD. 
_ 14 GROSS ST., HATTON GARDEN, E.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 
supérior objective, 
either 6, 8, 9, or 12 
inches focus, 
2f-inch diameter, 
condenser 
4]-inch diameter, 
and “high-power 
hmelight burner, in 
travelling case, 
£900 
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. 
A New Barograph—THE ‘‘ JORDAN.” 
(Regd. Design 62871.) 
Shows at a glance the movements of the barometer during 
the preceding days. 
c Descriptive Leaflet post free on application to 
NEGRETTI & ZAMBRA, 
38 HOLBORN VIADUCT, E.C.; 
45 CORNBILL, E.C.; 122 REGENT ST., W. 
