cexlvi NATURE [DECEMBER 4, I913. 
Atunpum MurFLes 
In furnaces heated by electricity Alundum 
Muffles will stand many more heats than the 
ordinary clay muffles and give the furnace 
greater efficiency in operation because of 
their high thermal coaductivity. 
NOW READY. 
NEW LIST 
RHEOSTATS 
FOR 
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ISENTHAL & CO. Sole Agents, in the United Kingdom, — 
(Department 1), F 
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Contractors to the Admiralty, War, India, and : \ 
Colonial Offices, &c. T OW N SO N & M E R CG E F . , 
Jan 
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34 CAMOMILE ST., LONDON, EC. 
IDEAL FOR SCHOOL-ROOMS. 
SCIENTIFIC INSTRUMENTS) | Watt Diagrams of Zoologia 
ALL DESCRIPTIONS. a 
is Sek and Botanical Specimens. 
SPECTROMETER. Each Diagram measures about 3} x 24 
s feet. The subjects are reproduced 
true to nature, the colouring is bold, 
and the figures stand out clearly on 
the matt black background. Each 
diagram represents one species only, 
and includes a view of the complete 
specimen as well as various aspects of 
its development and sectional struc- 
ture. An illustrated descriptive Key 
is supplied with each diagram. 
Since announcing these splendid dia- - 
grams in our Catalogue No. 52 of : 
A cheap and reliable Instrument specially designed tor me Rey a Se 
Students’ use. Charts and Maps (1909), seven have 
Very strongly constructed so that it may be used by : 
elementary pupils without being put out of order. been added to the Zoological and 
PRICE £2: 10:0 Each Net. twenty to the Botanical section. 
Descriptive Pamphlet on application. Price of each Diagram, Cloth 
PHILIP HARRIS &0., ro.) | Riso tao 
BIRMINGHAM. A. GALLENKAMP & CO., Lid 
19 & 21, Sun St., Finsbury Square, LONDON, E.C. 
{ENGLAND.) 
Printed by , RICHAR p Cray & Sons, Limirep, at Brunswick Street, Stamford Street, S.E., and published by MAcMILLA AN AND Co., LIMITED, at 
St. Martin's Street, London, W.C., and THe Macmiuian Co., 66 Fifth Avenue, } New York.—TxHurspay, December 4, 1913. 
