iy CONTENTS OF VOL. XVII. FIFTH SERIES, 



Page 

 Mr. A. P. Chattock on a Method of determining experimentally 



the Constant of an Electro-dynamometer Ill 



Mr. T. Muir on the General Equation of Differences of the 



Second Order 115 



Prof .B.Clausius on the Theory of Dynamo-electrical Machines. 119 

 Prof. S. P. Thompson on a new Insulating Support. (Plate 



HI.) : 134 



Mr. E. Y. Edgeworth on the Eeduction of Observations 135 



Mr. S. Newcomb on some Points in Climatology 142 



Prof. J. Tyndall on the White Eainbow 148 



Mr. W. W. J. Nicol on Equilibrium in Salt-Solutions 150 



On the Properties of Water and Ice, by Otto Pettersson 156 



On the Temperature obtained by Oxygen in a State of Ebul- 

 lition, and on the Solidification of Nitrogen, by M. S. 



Wroblewski 158 



A new Device for Measuring Power, by C. E. Brackett 159 



The Ergometer, by William Ashton 160 



NTJMBEE CV.— MAECH. 



Prof. E. Bunsen on the Condensation of Carbonic Acid on 



Smooth Glass Surfaces. (Plate V.) 161 



Dr. E. J. Mills on the Melting-point and Boiling-point as 



related to Chemical Composition 173 



Lord Bayleigh's Acoustical Observations. — V. (Plate IV.). . 188 

 Mr. S. P. Langley's Experimental Determination of Wave- 

 lengths in the Invisible Prismatic Spectrum. (Plates VIII. 



& IX.) ... 194 



Messrs. Lodge and Clark on the Phenomena exhibited by Dusty 

 Air in the neighbourhood of strongly Illuminated Bodies. 



(Plate VII.) 214 



Notices respecting New Books : — 



The Elements of Plane Geometry : Part I. (correspond- 

 ing to Euclid, Books I.-II.) 239 



Annuaire pour Tan 1884, publie par le Bureau des Longi- 

 tudes 241 



Mr. L. Clark's Manual of the Transit Instrument as used 



for obtaining Correct Time; and Transit Tables for 1884 242 

 Mr. E. W. Levander's General Index to the Eirst Twenty 



Volumes of the Astronomical Begister 243 



On Eainbow s and Glories, by Prof. Tyndall e . 244 



Elevation of Land during the Glacial Period, by Prof. Dana . . 245 

 On the Causes of the Production of Atmospheric Electricity 

 in general, in Storms, and in Heat Lightning, by M. de 



Tromelin 245 



Note on the Temperature of Sun-spots, by Prof. E. Wiedemann 247 

 New Solenoidal Galvanometer, by E. Bottcher 248 





