Supplement to “ Nature,” June 30, 1923 iii 
Bausch [omb 
Metallurgical 
‘Microscope 
CCM 
Designed by Dr. ALBERT SAUVEUR, Harvard University. 



Also 
PHOTOMICROGRAPHIC APPARATUS, 
etc., for METALLURGICAL WORK. 
MICROSCOPES FOR 
ALL REQUIREMENTS 
: Delivery from Stock. 
Full particulars on application. 
Bausch & lomb (ptical ©.|td. 
Contractors to British, Indian, Colonial & Foreign Governments, 
37-38 HATTON GARDEN, LONDON, E.C.1. 
Our instruments may be obtained through all Dealers. 


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GLEW’S SCINTILLOSCOPE 
(PATENT) 
HOWS a magnificent display of scintil- 
lations, showers of sparks, direct from the 
mineral Pitchblende, Radium, Polonium, 
Uranium, Thorium, or any radio-active substance, 
even an Incandescent Gas Seance contains sufficient 
Thorium to excite the very sensitive screen of the 

We 
Constructed to 
the design of 
Dri. Goes 
Scintilloscope, which is far more sensitive than 
the Spinthariscope. ‘Ihe Scintilloscope rivals 
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Alpha rays. 

The eye sees an inexhaustible shower of stars of white light, giving a very 
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GLEW'S SCINTILLOSCOPE, Superior Lens, with Extra-sensitive 
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Pieces of Pitchblende mineral, ground flat and polished, with Sensitive 
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F. HARRISON CLEW (Parenter), 156 CLAPHAM Road, LONDON, S.W.9. 
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And | other Gases. 
The British Oxygen Co. have works for the production 
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Special Terms quoted to the Trade. 
Catalogue and full particulars on application to the Head 
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LONDON, N.18. 

PNR (SS 
Herbert Smith, 
of the Mineral 
Department of 
the British 
Museum, and 
embodying 
many improve- 
ments over 
existing types. 

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SS 
THE STUDENTS ©&_ 
9 
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S 
7 
holder and attachments facilitate the measurements of 
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axial line. The graduated circle of 5 inches (12.5 cm.) » 
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ing by vernier to minutes of arc. £910 O 
J. H. STEWARD, Ltd. 
WJ 
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Scientific Instrument Makers to the British and Foreign Governments, ~ 
406 and 457 Strand, London, W.C.2. wx 
Established 1852. 
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The mirror is adjustable in any direction. The crystal ( 
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