NA TURE 



[September 21, 1905 



Ultra- Violet Rays 



THE 

 NEW 



MERCURY 



VAPOUR 



LAMP 



MADE OF 



UVIOL GLASS 



For Physical and 

 Medical Purposes. 



Current 



consumption only 2 



to 3 amperes. 



ISENTHAL & CO., 



85 MORTIMER STREET, LONDON, W. 



CATALOGUE of 

 PHYSICAL APPARATUS. 



^INTH EDITION. 



Oifr soft piii/es. pritfiiscli/ ill list I'dicd, of till 

 the Idtf'st ami most iiioilerii apparatus for 

 teach hill . . 



Heat, Light, Sound, 



Frictional and Voltaic Electricity, 



Pneumatics, Hydrostatics, Mechanics, 



Mensuration, Hygiene, &c. 



EVERY INSTRUMENT CHEAPLY, EFFICIENTLY, AND 

 ACCURATELY MADE. 



CATALOGUES SENT FREE, on application, to 

 Schools, Colleges, and Institutions. 



TOWNSON & MERCER, 

 34 CAMOIVIILE ST., E.G. 



NEW CIRCULAR BEAM CHEMICAL BALANCE. 



New Circular Beam Chemical Balance for a charge up to loo grammes in each I'an, 

 sensible to i/ioih part of a milligramme. In Mahogany Glass Case, with Polished Slate 

 Base, Counterpoised Sliding Front, Side Doors, Beam, divided in l/ioth of a milligramme. 

 P.ider Apparatus. All Knife-Edges are of Agate working on Agate Planes. Automatic 

 Arrestment for arrest of Pans and Beam. I'ans 7 cm. diameter. Level and Levelling 

 screws. £10 O O 



LIST OF BALANCES POST FREE. 



Illustrated Lists of Chemical and t hysical Apparatus also on applicaticn. 



C. E. IVltJLLER, OF^IVIE & CO., Ltd. 



Scientific Glass Blowers and Manufacturers of 

 Chemical and Physical Apparatus, 



148 HIGH HOLBORN, LONDON, W.C. 



^^^a^sass 



THE LONPON STEREOSCOPIC COOlPflNY'S 



LATEST INTRODUCTION 



Cbc "mm" Rcfkx Camera 



For Day-Light Loading Flat Films or Plates. 



fhe Ideal Camera for Photographing Figure Studies, Animals, Natural History 



Siilijecf^, Architecture, Landscapes, &c. 

 The picture can be viewed the full size and focussed right up to the moment 



of exposure. 



Write for Fully Illustrated Booklet (N) Free from 



106 & 108 REGENT ST., W., or 54 CHEAPSIDE. 



Printed by RrcHARD Clay and Son.s, Limited, at 7 & 8 Bread Street Hill, Queen Victoria Street, in the City of Lonuon, and publi-hed by MACMiLUAh 

 AND Co., LiMlTED.at St. Martin's Street, London, W.C, and The Macmillan Company, 66 Fifth Avenue, New Vork,— Thursday, September 21, 1905. 



