VI 



January 6, 1870. Page 

 List of Presents 130 



Some Account of the Suez Canal, in a Letter to the President. By J. F. 

 Bateman, F.E.S 132 



January 13, 1870. 



List of Presents 144 



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

 M.A., Professor of Mineralogy in the University of Oxford, and Keeper 

 of the Mineral Department, British Museum 146 



On Fluoride of Silver.— Part I. By George Gore, F.R.S 157 



Approximate determinations of the Heating-Powers of Arcturus and a Lyrae. 

 By E. J. Stone, F.R.S., First Assistant at the Royal Observatory, Green- 

 wich 159 



January 20, 1870. 



List of Presents 165 



On the Mechanical Performance of Logical Inference. By W. Stanley 

 Jevons, M.A. (Lond.), Professor of Logic &c. in Owens College 166 



Preliminary Paper on certain Drifting Motions of the Stars. By Richard 

 A. Proctor, B.A., F.R.A.S 169 



On Jacohi's Theorem respecting the relative Equilibrium of a Revolving 

 Ellipsoid of Fluid ; and on Ivory's Discussion of the Theorem. By L 

 Todhunter, M.A., F.R.S., Late Fellow of St. John's College, Cambridge. 171 



January 27, 1870. 



List of Presents 171 



Observations on the Temperature of the Strata taken during the sinking of 

 the Rose Bridge Colliery, Wigan, Lancashire, 1868-69. Bv Edward 

 Hull, M.A., F.R.S., Director of the Geological Survey of Ireland 173 



On the Action of Rays of High Refrangibility upon Gaseous Matter. By 

 John Tyndall, LL.D., F.R.S., Professor of Natural Philosophy in the 

 Royal Institution 176 



On the Theory of Continuous Beams. By John Mortimer Heppel, Mem. 

 Inst. C.E 176 



Remarks on Mr. Heppel's Theorv of Continuous Beams. By W. J. Mac- 

 quorn Rankine, C.E., LL.D., F.R.S 178 



Remarks on the recent Eclipse of the Sun, as observed in the United States. 

 By J. N. Lockyer, F.R.S 179 



No. 117.— February 3, 1870. 



Note on an Extension of the Comparison of Magnetic Disturbances with 

 Magnetic EfFects inferred from observed Terrestrial Galvanic Currents ; 

 and Discussion of the Magnetic Effects inferred from Galvanic Currents 

 on days of tranquil magnetism. By George Biddell Airy, Astronomer 

 RoyalJ F.R.S 184 



Monthly Magnetic Determinations, from December 1866 to May 1869 in- 

 clusive, made at the University of Coimbra. By Professor J. A. de Souza, 

 Director of the Observatory 185 



