V 



December 22, 1870. Page 



On the Extension of the Coal-fields beneath the Newer Formations of Eng- 

 land ; and the Succession of Physical Changes whereby the Coal-mea- 

 sures have been reduced to their present dimensions. By Edward Hull, 

 M.A., F.R.S., F.G.S., Director of the Geological Survey of Ireland 222 



On the Constitution of the Solid Crust of the Earth. By the Ven. John 

 Henry Pratt, Archdeacon of Calcutta, M.A., F.R.S 223 



Actinometrical Observations made at Dehra and Mussoorie in India, Octo- 

 ber and November 1869, in a Letter to the President. By Lieut. J. H. N. 

 Hennessey 225 



January 12, 1871. 



On Fluoride of Silver.— Part II. By George Gore, F.R.S 235 



Some Experiments on the Discharge of Electricity through Rarefied Media 

 and the Atmosphere. By Cromwell Fleetwood Varley 236 



Polarization of Metallic Surfaces in Aqueous Solutions, a new Method of 

 obtaining Electricity from Mechanical Force, and certain relations be- 

 tween Electrostatic Induction and the Decomposition of Water. By 

 Cromwell Fleetwood Varley 243 



January 19, 1871. 



On the Structure and Development of the Skull of the Common Frog 

 (Rana temporaria). By W. Kitchen Parker, F.R.S 246 



Method of measuring the Resistance of a Conductor or of a Battery, or of 

 a Telegraph-Line influenced by unknown Earth-currents, from a single / 

 Deflection of a Galvanometer of unknown Resistance. By Henry Mance, 

 Superintendent Mekran Coast and Persian Gulf Telegraph Department, 

 Kurrachee 248 



Measurement of the Internal Resistance of a Multiple Battery by adjusting 

 the Galvanometer to Zero. By Henry Mance , 252 



Modification of Wheatstone's Bridge to find the Resistance of a Galvano- 

 meter-Coil from a single deflection of its own needle. By Prof. Sir Wil- 

 liam Thomson, F.R.S.' 253 



On a Constant Form of Daniell's Battery. By Prof. Sir William Thomson, 

 F.R.S 253 



On the Determination of a Ship's Place from Observations of Altitude. By 

 Prof. Sir William Thomson, F.R.S 259 



January 26, 1871. 



On the Mineral Constituents of Meteorites. By Nevil Story Maskelyne, 

 M.A., F.R.S., Professor of Mineralogy, Oxford, and Keeper of the Mineral 

 Department, British Museum 266 



On the Organization of the Catamites of the Coal-measures. By W. C. 

 Williamson, F.R.S., Professor of Natural History in Owens College, Man- 

 chester 268 



On Approach caused by Vibration. A Letter from Prof. Sir W. Thomson, 

 LL.D., F.R.S., &c. to Prof. Frederick Guthrie, B.A 271 



List of Presents 273 



