A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE,» 
“To the solid ground : : 
Of Nature trusts the mind which builds for aye.’-—WorpDswortTH. 
No. 2313, VOL. 92] THURSDAY, FEBRUARY 26, 1914 [PRICE-SIXPENCE | 
Registered as a Newsnaper at the General Post Office.) 
(All Rights Reserved, 
BALANCES & WEIGHTS 
BUY DIRECT FROM 
FE-BECKER & CO. BATION WALL, 
- (W.&J. GEORGE, LTD., SUCC#=) vi LONDON, E C. 
Jou J. GRIFFIN " Sons LC” 
KEMBLE $7., KINGSWAY. LONDON, W.C. 
WEST’S APPARATUS 
FOR MEASURING 
THE PRESSURE OF LIGHT 
. A very simple method of measuring the pressure of radiation from an 
electric lamp. (See Proc. of the Phys. Soc. of London, Aug. 15, 1913.) 
ELECTRIC HOT PLATES 
FOR LABORATORY USE 
(Heraeus System). 
With Automatic Temperature Control. 
‘Any temperature up to 250° C. maintained constant (by 
electrically-actuated relay) to within | or 2 degrees, 
REYNOLDS & BRANSON, Ltd. 
Chemical and Scientific Instrument Makers to His Majesty’s 
Government (Indian, Home, and Colonial), Laboratory 
Furnishers, Manufacturing Chemists and Opticians. 
THE STUDENT’S MICROTOME 
This Microtome will be found extremely useful for Students in Physi- 
ology, Botany, &c. The instrument is arranged to slide on a glass plate ; 
the substance to be cut is embedded and fixed on the glass plate. Sections 
of any degree of thickness may be cut by rai-ing or lowering the screw, 
and the Microtome is arranged so that any razor may be clamped to it. 
Price, with glass plate and roughened spot to hold substance, s. d. 
without razor ee oot ay ave aa Bae --- each 4 O 
Razors .. aa nn aeecees a ae each 1/38 and 2 O 
Wew Catalogue of Microscopes, Accessories, and Dissecting Instruments 
now in the press. 
A4. COMMERCIAL. STREET, LEEDS. 
ANEMOMETER 
recording the PRESSURE 
and the DIRECTION 
of the wind simultaneously 
upon one chart. 
Price £35. 
Descriptive pamphlet, and 
list- of “ Meteorological 
Instruments” free . on 
request. 
NEGRETTI & ZAMBRA 
? 
38 Holborn Viaduct, London, E.C. 
City Branch: 45 Cornhill, E.C. 
West End: 122 Regent St., W. 
SI 
