xiv 
RHEOSTATS 
We now holda 
LARGE STOCK 
of 
Resistances of the Slate 
and Tubular Types, and 
can supply immediately. 
Loading Resistances with 
our New Units built to 
specification. 
ISENTHAL & CO. 
(Department 1), 
DENZIL WORKS, NEASDEN, LONDON, N.W. 
Contractors to the Admiralty, War, India, ana 
Colonial Offices, &c. 
SCIENTIFIC INSTRUMENTS 
OF ALL DESCRIPTIONS. 
The “HARRIS.” 
SPECTROMETER. 
A cheap and reliable Instrument specially designed for 
Students’ use. 
Very strongly constructed so that it may be used by 
elementary pupils without being put out of order, 
PRICE £2:10:0 Each Net. 
Descriptive Pamphlet on application. 
PHILIP HARRIS & CO., iro. 
BIRMINGHAM 
(ENGLAND.) 
NATURE 
[OcroBER 9, 1913 
MIDGET FURNACE 
FOR USE WITH BUNSEN BURNER. 
eee a a 
The inside lining of this furnace is _ 
hardened by a special process to with- 
stand great heat. 
a es 
With 3%" burner, complete 4/6 
y 2" 7 7) 6/6 as $ 
TOWNSON & MERCER, | 
- 34 Camomile Street, London, E.C. 7 
NEW ELECTRICAL FURNACE © 
FOR TEMPERATURES UP TO 
1000° C. or 1800° F,. 
i 
| 
The consumption of current in this Furnace is far less than 
in the more costly Platinum wound Furnaces. : 
APPLICATIONS OF THE FURNACE. 
Determination of the Critical Points of Steel. Darling's ‘‘ Heat for 
Engineers.” 
Annealing of specimens of Metals for microscopic examination. 
Asa ‘black body” standard for heat radiation or luminosity. 
For demagnetising iron or steel rods, prior to performing tests for — 
saturation, &c. 
As a Combustion Furnace for the Determination of Carbon in Steels. 
NVALUABLE FOR LABORATORY AND LECTURE ROOM USE. 
De” Write for Circular No, 105A, giving full particulars. q 
ELECTRIG HOT PLATES. 
NO EXTERNAL RESISTANCE REQUIRED. 
Specially Recommended for Extractions~ with 
Volatile Liquids and General Laboratory Work. 
SUITABLE FOR DIRECT OR ALTERNATING CURRENT 
Plates can be taken apart in a few seconds and a new 
heating resistance inserted. 
From G/= each. if 
A. GALLENKAMP & CoO., Ltd., 
Manufacturers and Importers of Scientific Apparatus, 
19 & 21 SUN STREET, FINSBURY SQUARE, 
LONDON, E.C. 
se tye 
aa Write for Circular 
No. 128A. 
Printed by Richarp Cray & Sons, Limrren, at Brunswick Street, Stamford Street, S.E., and published by MACMILLAN AND Co., LimrTEp, at 
St. Martin's Street, London, W.C., and THE MACMILLAN Co., 66 Fifth Avenue, New York.—THurspay, October 9, 1913. 
