CONTENTS OF VOL. XXV. FIFTH SERIES. VL1 



Page 

 Mr. C. V. Boys's Experiments with Soap-bubbles. (Plate II.) 409 

 Mr. B. H. M. Bosanquet on the Use of the term " Besistance " 



in the Description of Physical Phenomena 419 



M. W. Michelson's Theoretical Essay on the Distribution 



of Energy in the Spectra of Solids 425 



Notices respecting New Books : — 



Prof. W. C. Unwin's Testing of Materials of Construction 436 

 Proceedings of the Geological Society : — 



Mr. H. Fox on the Gneissic Bocks off the Lizard 438 



Eev. J. F. Blake on the Monian System 439 



Prof. Y. Ball on some Eroded Agate Pebbles from the 



Soudan 442 



Prof. V. Ball on the probable Mode of Transport of 

 fragments of Granite and other Bocks which are found 

 imbedded in the Carboniferous Limestone of the 



neighbourhood of Dublin 443 



Messrs. Gardner and Keeping on the Upper Eocene, com- 

 prising the Barton and Upper Bagshot Formations . . 444 

 Mr. W. Hill on the Lower Beds of the Upper Cretaceous 



Series in Lincolnshire and Yorkshire 445 



Dr. Hicks and Mr. De Bance on the Cae-Gwyn Cave, 



North Wales 446 



On the Thermal Conductivity of Hard and Soft Steel, by F. 



Kohlrausch 448 



Mountain Formation, by Joseph LeConte 450 



On the Action of Light on the Electrical Conductivity of the 



Haloid Salts of Silver, by Svante Arrhenius 451 



Glacial Motion, by Joseph LeConte 452 



NUMBEE CLVIL— JUNE. 



Mr. W. E. Sumpner on the Variation of the Coefficients of 

 Induction. (Plate HI.) 453 



Profs. "W. E. Ayrton and J. Perry on the Efficiency of 

 Incandescent Lamps with Direct and Alternating Currents 476 



Mr. E. C. Bimington on the Measurement of the Power sup- 

 plied to the Primary Coil of a Transformer 482 



Dr. C. H. Draper on the Polarization of Platinum Plates .... 487 



Profs. "W. E. Ayrton and J. Perry on the Magnetic Circuit of 

 Dynamo Machines. (Plate IV.). . . . : 496 



Mr.'H. F. Newall on the Becalescence of Steel 510 



Mr. J. Parker on an Extension of Carnot's Theorem 512 



Notices respecting New Books : — 



Transactions of the Edinburgh Geological Society, Vol. V., 

 Part III 514 



