CONTENTS. 



VOL. XXIX. 



No. 196.— May 1, 1879. 



Page 



List of Candidates for Election ...... ., .. .......... 1 



A Magnetic Survey of the Fortieth. Parallel in North America between 

 the Atlantic Ocean and the Great Salt Lake, Utah. By T. E. Thorpe, 

 Ph.D., F.R.S., Professor of Chemistry, Yorkshire College, Leeds 1 



On certain Definite Integrals occurring in Spherical Harmonic Analysis, 

 and on the Expansion in Series of the Potentials of the Ellipsoid and 

 of the Ellipse. By W. D. Niven, M.A., Fellow of Trinity College, 

 Cambridge 2 



On the Origin of the Parallel Eoads of Lochaber, and their bearing on 

 other Phenomena of the Glacial Period. By Joseph Prestwich, M.A., 

 F.R.S., E.G.S., &c, Professor of Geology in the University of Oxford .... 6 



May 8, 1879, 



On the Sensitive State of Electrical Discharges through Rarefied Gases. 

 By William Spottiswoode, P.R.S., andS. Fletcher Moulton, late Fellow 

 of Christ's College, Cambridge 21 



On the Action of Solid Nuclei. By Charles Tomlinson, F.R.S. 24 



On the Results of the Magnetical Observations made by the Officers of the 

 Arctic Expedition, 1875-76. By Staff-Commander E. W. Creak, R.N., 

 attached to the Admiralty Compass Department 29 



On the Relation between the Diurnal Range of Magnetic Declination and 

 Horizontal Force, as observed at the Royal Observatory, Greenwich, 

 during the years 1841 to 1877, and the Period of Solar Spot Frequency. 

 By William Ellis, F.R.A.S., Superintendent of the Magnetical and 

 Meteorological Department, Royal Observatory, Greenwich 43 



