CONTENTS OF VOL. XXI. FIFTH SERIES. V 



Page 

 Mr. Cunynghaine on a Mechanical Method of Solving Quad- 

 ratic and Cubic Equations, whether the Hoots be real or 



Impossible 260 



Dr. O. Lodge on the Seat of the Electromotive Eorces in 

 Voltaic and Thermoelectric Piles. Reply to Professors 



Ayrton and Perry 263 



Notices respecting New Books :— 



Dr. H. E. Morley's Outlines of Organic Chemistry ; Miss 

 A. M. Clerke's Popular History of Astronomy during 



the Nineteenth Century 277, 279 



Proceedings of the Geological Society : — 



Mr. W. H. Hudleston on a recent Section through 

 Walton Common, exposing the London Clay, Bagshot 



Beds, and Plateau-gravel 281 



Mr. J. A. Brown on the Thames Valley Surface-deposits 

 of the Ealing District and their associated Palaeolithic 



Eloors 283 



Messrs. W, Hill and A. J. Jukes-Browne on the Mel- 

 bourn Bock and the Zone of Belemnitella plena, from 



Cambridge to the Chiltern Hills 283 



Mr. W. Hill on the Beds between the Upper and Lower 

 Chalk of Dover, and their comparison with the Middle 



Chalk of Cambridgeshire 284 



On the Velocity of Efflux of Liquids, by M. Vautier 285 



A Method of precisely Measuring the Vibratory Periods of 



Tuning-forks, by Prof. A. M. Mayer 286 



On the Permeability of Various Diaphragms, by A. Zott .... 288 



NUMBEB CXXXL— APBIL. 



Mr. A. P. Laurie on the Electromotive Eorces developed 

 during the Combination of Zinc and Iodine in presence of 

 Water 289 



Mr. W. C. Unwin on the Belations of Pressure, Temperature, 

 and Volume in Saturated Vapours 299 



Mr. E. T. Edgeworth on the Law of Error and the Elimina- 

 tion of Chance , . . 308 



Prof. S. U. Pickering on Experimental Error in Calorimetric 

 Work 324 



Prof. S. U. Pickering on Delicate Calorimetric Thermometers 330 



Prof. Tait on the Eoundations of the Kinetic Theory of Gases 343 



Mr. A. Schuster on the Diurnal Period of Terrestrial Mag- 

 netism 349 



Dr. G. Gore on the Peltier Effect at different Temperatures . 359 



Proceedings of the Geological Society : — 



Bev. P. B. Brodie on two Bhsetic Sections in Warwick- 

 shire 362 



