V1U CONTENTS OF VOL. XXV. — FOURTH SERIES. 



Pass 

 Mr. J, Fergusson on recent Changes in the Delta of the 



Ganges 555 



On the Osculating Twisted Cubic to a curve of Double Curva- 

 ture, by Sir William Rowan Hamilton, LL.D., &c 556 



On the Inductive Capacity of Insulating Bodies, by M. Gaugain. 556 

 Index , 559 



PLATES. 



I. Illustrative of Prof. W. Thomson's Paper on the Secular Cooling of 



the Earth. 



II. III. IV. Illustrative of Prof. Maskelyne and Dr. Lang's Mineralogical 



Notes. 



V. Illustrative of Mr. S. V. Wood's Paper on the events which produced 



and terminated the Purbeck and Wealden Deposits of England 

 and France, &c. 



VI. VII. VIII. IX. Illustrative of Prof. Maskelyne and Dr. Lang's Mine- 



ralogical Notes. 



ERRATA. 



Page 16, line 8, and passim, for objective tube read stage. 



— 16, — 17, for bright inscription on dark ground read dark inscrip- 



tion on bright ground. 



— 16, — 42, for rectangular read perpendicular. 



— 17, — 16 for objective stand read stage, and for objective holder read 



clamping-piece. 



— 17, — 36, for is in read must be placed at. 



— 19, — 13, for observed read absorbed. 



— 19, — 1 8, for horizontally read perpendicularly. 



— 20, — 23, for will rea d does. 



— 23, — 21, read from the conductor of one electrical machine to an- 



other, observed directly under the microscope, gives, &c. 



— 32, in equation (5), for 770 millims. read 760 millims. 



— 33, line 7 from the bottom, for theoretically read theoretically. 



— 36, Table II., heading of third column from the right, for 00°05 



read -00205. 



— 165, line 13, for tubes read tube. 



irr wr /■ m0l2(T i P(r 



— 16b, last line, for — p read innnp • 



— 170, line 2, for A -\-w readH+w. 



— 293, — 10, for («+l) read 09+1). 



— 293, — 19, for J? read 1 : 5. 



Vi V, 



— 293, last line but one, last word, read arithmetical. 



— 294, line 3, for 2p read 2p Q '. 



— 297, — 2, for va read p a . 



