CONTENTS of N° 302.— Fourth Series. 



LII. On the Expansion of Superheated Vapours. By Dr. Hee- 

 MAnk Heewig page 401 



LITE. On Duplex Telegraphy. By Olivee Heaviside, Great 

 Northern Telegraph Company, Newcastle-on-Tyne. ("With a Plate.) 426 



LIV. On the Theory of the Normal Magnet, and the means of 

 augmenting indefinitely the Power of Magnets. By M. J. Jamtn". . 432 



LV. On the Law of G-aseous Pressure. By the Hon. J.W. Stetttt, 

 late Fellow of Trinity College, Cambridge 438 



LVL On some Improvements in Electromagnetic Induction Ma- 

 chines. By H. Wilde, Esq. (With a Plate.) 439 



LYII. The first Extension of the term Area to the case of an 

 Autotomic Plane Circuit. By Thomas Mttie, M.A., Assistant to 

 the Professor of Mathematics in Glasgow University 450 



LYIII. Note on a Crystallized Compound of Sesquioxide of Iron 

 and Lime. By John Peecy, M.D., P.E.S., Lecturer on Metallurgy 

 at the Eoyal School of Mines, London 455 



LIX. Notices respecting New Books : — The Strength of Materials 

 and Structures. By John Andeeson, C.E., LL.D., E.E.S.E., &c. 

 —British Eainfall, 1872. Compiled by Gr. J. Stmons. — Weekly 

 Weather Eeports issued by the Meteorological Office 457-460 



LX. Proceedings of Learned Societies : — 



G-eological Society : — Mr. H. Hicks on the Tremadoc Eor\s 

 in the neighbourhood of St. David's, South Wales ; the Eev. 

 O. Pishee on the Phosphatic Nodules of the Cretaceous Eock 

 of Cambridgeshire ; Mr. W. J. Sollas on the Yentrieulitidae 

 of the Cambridge Upper Grreensand 460-462 



LXI. Intelligence and Miscellaneous Articles :— 



American Astronomy 462 



On the sudden Cooling of Melted Grlass, and particularly on 



" Eupert's Drops," by V. de Luynes 464 



On a Method of measuring Induced Currents, by P. H. Bigelow. 467 



Index 469 



With Title-page, Contents, &c. 



* 



It is requested that all Communications for this Work may be addressed, 

 post-paid, to the Care of Messrs. Taylor and Francis, Printing Office, Red 

 Lion Court, Fleet Street, London. /y 





