X CONTENTS. 



Page 

 On tlie Displacements of the Rotational Axis of the Earth. By Professor W, 

 FoRSTEE 476 



A Lecture-room Experiment to illustrate Fresnel's Diffraction Theory and 

 Babinet's Principle. By Professor A. Coent;, F.R.S 480 



The Connection between Chemical Combination and the Discharge of Elec- 

 tricity through Gases. By J. J. Thomson, F.R.S 482 



On the Electrification of Molecules and Chemical Change. By H. Beeeeton 

 Bakee 493 



Report on Planimeters. By Professor 0. Henrici, F.R. S 496 



On Methods that have been adopted for Measuring Pressures in the Bores of 

 Guns. By Captain Sir A. Noble, K.C.B., F.R.S., M.Inst.C.E 523 



