SSS—S = 
A WEEKLY ILLUSTRATED JO 
ust * 
, <—).. 
URNAL OF SCIENGHonal! 
‘To. the solid ground 
Of Nature trusts the mind which builds for aye.’-—WorDSWORTH. 
No. 2294, VOL. 92] 
THURSDAY, OCTOBER 16, 1913 
[Prick SIXPENCE 
Registered as a Newspaper at the General Past Office.) 
[All Rights Reserved. 
ib 
NEWTON & CO.’s 
“ DEMONSTRATOR’S” 
SCIENCE 
LANTERN. 
Illustrated Catalogue 
Post Free on request, 
‘+ 
ere 
Petes OE 
MORE STREET, LONDON, W. 
STUDY 
tue LENS 
It is the Key to Success in Photography. 
Who can expect to excel who does not understand 
how fo use the diaphragm, the swing- back, the 
rising front, focussing scale, &c., &c.? All such 
questions are lucidly and simply explained in 
“PHOTOGRAPHIC LENSES : 
A SIMPLE TREATISE.” 
350 pages, 44 plates, numerous diagrams and 
illustrations, cloth bound. 
‘Rg re BECK, Ltd.. 88, CORNHILL, 
* London, E.C. 
GRAND PRIX AWARD, TURIN, 
SOLE AUTHORISED MAKERS OF 
STROUD & RENDELL SCIENCE LANTERNS. 
The ‘* University” Lan- 
tern, with Russian iron 
body, sliding baseboard, two 
superior objectives, plane 
silvered mirror “A,” which 
is moved by a knob causing 
the rays to be reflected 
upwards for the projection of 
objects in a horizontal plane, 
condensers 4} in. ciam., prism 
with silvered back which can 
be used at “C,” or as an 
erecting prism in mount ‘‘ D,” 
lime-light burner, slide carrier. 
Price complete in_ travelling 
case, without reversible adjust- 
1 
able stage ‘‘ B,” £10 6 
Ditto, ditto, with “ Phoenix” Arc Lamp... es cas eo 0d foe O 
Reversible adjustable stage ‘‘ B" for supporting apparatus, extra rae 
The ‘* College’ Lantern, without adjustable stage, with 
lime-light burner complete i os lore oct ae Bee 
Ditto, ditto, with “Phoenix” arc lamp... ea ate «9 4000 
Slit and prism for spectrum with support, for either lantern... 1 7.6 
Polariser and analyser ... ; = 00 
Catalogues post free. 
Optical Lanterns and Accessory Apparatus (New Edition). 
Abridged List of Chemical Apparatus and Chemicals, 44 pages. 
Mechanical Models for teaching Building and Machine 
Construction, 
14 COMMERCIAL STREET, LEEDS. 
Negretti & Zambra’s Latest 
Autographic Rain Gauge, 
The ‘FERNLEY,’ 
provides frictionless action 
without delicate mechanism, 
very open rain and time 
scales, and a chart with 
uniform spacings, 
For particulars, and explanation 
of diagram, write for pamphlet to 
| NEGRETTI » ZAMBRA 
\\/4c 38 Holborn Viaduct, London, E.C. 
City Branch: 45 Cornhill, E.C. 
West End: 122 Regent St., W. 
