q JUNE 30, 1923] NATURE che 
4 OO aaa $$$ ———————— 
INTERFERENCE 
ACCESSORY 
FOR TESTING 
MICROSCOPE STANDS 
AND 
FINE ADJUSTMENTS 
Designed for and used by the Department of Applied 
Optics, National Institute for Medical Research, London. 

Full particulars on application to the Makers :— 
ADAM HILGER Ltd. 
Ny 75a Camden Road, London, N.W.1 
(Entrance : 24 Rochester Place—adjoining) 
a Telephone Numbers : NORTH 1677-8. 
ee al Telegraphic Address: SPHERICITY, PHONE, LONDON. 



aE THE 
If the bonuses just declared continue ZEISS ES 
uninterruptedly an assurance for 
£1,000 payable at the end of 25 
years (or at death), which costs 
BINOCULAR MAGNIFIER 
about £40 a year, will produce 
£1,500 at the end of the term. 
Equitable Life ms 
Extra interchangeable lenses, per pair. 2 0 4 
Assurance Society Complete illuminating attachment : 
The magnifier can be supplied to suit interpupillar 
distances of either 59 mm., 62 mm., 65 mm., or 


With one pair of lenses, in case . 5 ane 
Mansion House Street, London, E.C.2. 68 mm., with lenses x ‘75, x 1, x2, x 2°5, and x3. 
W. Palin Elderton, Actuary and Manager DELIVERY ‘FROM STOCK 
DISTRIBUTORS 
No Shareholders No Commission 
alum J. W. ATHA & CO. 
SENAY 8 Southampton Row, London, W.C.1. 


