MARCONI'S 



WIRELESS TELEGRAPH CO. 



Ltd., 



May 1 8, 1905 J NATURE 



7800° C. 



is the temperature of the Sun (black 

 body temperature), as determined 

 by Professor C. Fery by means of 

 his Radiation Pyrometer. 



The Fery Radiation Pyrometers 

 are available for temperatures from 

 500 C. [i.e. below a red heat) up to 

 any higher limit. 



WRITE FOR LIST 30 N TO 



The Cambridge Scientific Instrument Co., Ltd., 



CAMBRIDGE, ENGLAND. 



SOLE AGENTS for the United Kingdom, British Colonies, 

 and United States of America. 



(AGENTS ALSO FOR THE SALE OF THESE INSTRUMENTS 

 IN RUSSIA.) 



MANUFACTURERS OF 



High-Class Apparatus for Rontgen 

 Ray and High Frequency Work. 



10",12& 14 INDUCTION COILS. 



PORTABLE HOSPITAL SETS, 



SWITCHBOARDS, &c., &c. 



New Descriptive Price List Free on Application to 



18 Finch Lane, London, EX. 



Autotype Company 



74 NEW OXFORD STREET, LONDON, 



Iiivili- Enquiries ji\'in those seeking 



PERIVIANENT ^^=^ 

 Photographic Reproductions 



Of the Highest r.'ssible Excellence. 



THE COMPANY'S PROCESSES- 



Autotype Solar (Carbon). 

 Autotype Mechanical (Collotype). 

 AutoGravure (Copper-plate Engraving). 



ARE EMPLOYED BY— 



The Trustees of the British Museum. 

 The Local Government Board. 

 Many Learned Societies, Leading Publishers, 

 and Artists of Repute. 



Examples of U'oi-I; 



lay be inspected ami alt ijifoniialio 

 o/>/a/iied al— 



The Autotype Fine Art Gallery, 



74 NEW OXFORD STREET, LOxMJON, W.C. 



JENA LABORATORY GLASSWARE. 



BOILING FLASKS, BEAKERS. 



RETORTS, TEST TUBES, TUBING 



FOR EXPLOSION FURNACES. 



COMPOUND TUBING (D.R.P.) 



Resisting in a high aeatee sudden 



changes of temperature and the 



action of corrosiue chemicals. 



Combustion Tubing for Elemen- 

 tary Analysis, CTipiiJaln'") 

 SCHOTT & GEN. Glassworks, Jena (GERMANY). 



' '"' ' "" ■ wilb the following firms : 



The Jena Glasses are, in the U.K. 

 Aberdeen. 

 A. & J. SMITH, 23 and 25 St. 

 Nicholas Street 



BiriiiinBhaiu. 



F. E.BECKER & CO. (W. and 



J. George, Ltd., Successors), 159 



and 160 Great Charles Street. 



PHILIP HARRIS & Co., Ltd., 



Edmund Street. 



Dublin. 

 F. E. BECKER & CO. (W. and 

 J. George, Ltd., Successors), i8z 

 Great Brunswick Street. 

 PHILIP HARRIS & Co., Ltd., 

 179 Great Brunswick Street. 

 Olasgon'. 

 F. E. BECKER & CO. (W. and 

 J. George, Ltd., Successors), 36 

 Renfrew Sli 



AlaiicheNler. 



FREDK. JACKSON & Co.. 



14 Cross Street. 



JAMES WOOLLEY, SONS & 



Co.. Ltd., Victoria Bridge. 



Vi'»<'nNll<'.nii<>ii-T]iio. 



BRADY & MARTIN, Ltd. 



LuuUoii. 



BAIRD & TATLOCK (London) 



Ltd., 1, Crus, Street, Hatton 



Garden. E.C. 

 F. E. BECKER & Co. (W. and J. 



George, Ltd. , Successors), 33 to 37 



Hatton W.,11. Hatton Garden, E.C. 

 A. CALLENKAMP & Co., Ltd.. 



i9&2oSunStrett. Finsbury,E.C. 

 JOHN J. GRIFFIN & SONS. 



Ltd., 20-26 Sardinia Street. 

 Fields. W.C. 



Leeds. Lincol 



REYNOLDS & BRANSON, Ltd., TOWNSON & MERCER, 



14 Commercial .Street. Tamumile Street. F..C 



_14 



C. S A.1iS.-Ei.TR-' S 

 AI>LAN^ATIC LENSES. 



Magnifying 6, 10, 15, and 20- 



IS/- each, in Tortoisashell or Nickel 



Plated Pocket Mounts. By post upon 



receipt of remittance 



2« HIGH HOLBORN, LONDON, W.C. 



