iv Supplement to “ Nature,” 
June 30, 1923 


e1tz 
NEW MICRO-PROJECTION 
EQUIPMENT 
WITH SPECIAL COLLIMATOR 
OF GREAT LICHT TRANSMITTING POWER 
(For use with any microscope) 
Owing to the exceptional high degree of 
correction in the illuminating system, a 
brilliant and sharp image is obtained with 
an arc lamp taking only 4°5 amps. 
The illumination is sufficient to project 
objects under polarised light, and various 
accessories can be supplied for this 
purpose. 
Descriptive pamphlet on request. 
OGILVY & CO. 
(British Agents for E, Leitz) 
18 BLOOMSBURY SQ., LONDON, W.C.4. 
Optical and Mechanical Repairs to any make of 
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ag Army Field Glass . 7 £1 0 
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25 X, 37 Draw, Sling Telescope . Sra 
15x and 30X, 2-Power, 3-Draw, Sling Telescope 2 5 
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8x Ex-Service Glass, with case a 
8x Ditto, Ditto, almost new ae ag 
8x Ditto, perfectly new 310 
OX 4, ” ” 410 
I2X 5, ” , 5 0 
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All Subject to Approval. 
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Note Address: 
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ocoo 
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~ Seeing 
1S 







Believing 

In nature there are many things happening that even 
its closest students can hardly believe true. 
A pair of Ross Binoculars is one of the most essential 
items in a naturalist’s outfit. They will reveal the 
habits and ways of birds and animals in a way that 
is little short of wonderful. 

No other Binoculars will give you such illumination 
and detail, two most essential factors, as those made 
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| Send for copy of illustrated booklet with introduction 
| by Mr. Cherry Kearton, the world-famous naturalist. 
. ROSS LTD. 
CLAPHAM COMMON, LONDON, S.W.4. 
Showrooms at 13-14 Great Castle Street, 
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B-S QUARTZ SPECTROGRAPHS 
For use with the B-S Ultraviolet Polarimeters. 






Upon receipt of require- 
ments full particulars of 
my the appropriate instrument 
—/ will be forwarded together 
with aspecimen photograph. 








Polarimeter accessories 
always in stock. 


BELLINGHAM & STANLEY Ltd., 71 HORNSEY RISE, LONDON, N.19. 


PRINTED IN GREAT BRITAIN BY R. & R- CLARK, LTD., EDINBURGH, 
es 
