CONTENTS OF VOL. XXX 



(FIFTH SERIES). 



NUMBER CLXXXIL— JULY 1890. 



Page 

 Mr. A. A. Michelson on the Application of Interference 



Methods to Astronomical Measurements. (Plates I. & II.) 1 

 Mr. J. Brown on the Electrification of the Effluvia from 



Chemical or from Voltaic Reactions 21 



Lord Rayleigh on Huygens's Gearing in illustration of the 



Induction of Electric Currents 30 



Mr. J. S. Ames on Relations between the Lines of Various 

 Spectra, with [Special Reference to those of Cadmium and 



Zinc, and a Redetermination of their Wave-lengths 33 



Mr. J. S. Ames on some Gaseous Spectra : — Hydrogen, 



Nitrogen 48 



Prof. W. E. Ayrton, Mr. T. Mather, and Dr. W. E. Sumpner 



on Galvanometers 58 



Mr. E. P. Culverwell on Boltzmann's Kinetic Theory of Gases, 

 and on Sir W. Thomson's Address to Section A, British 



Association, 1884 95 



Prof. R. Threlfall on the Elastic Constants of Quartz Threads ; 



with a Note by Prof. C. V. Boys 99 



Notices respecting New Books : — 



Mr. H. Whiting's Short Course of Experiments in Physical 

 Measurements. — Part J. Densitv, Heat, Light, and 



Sound ". 118 



Proceedings of the Geological Society : — 



Prof. J. Prestwich on the Relation of the Westleton Beds 



or " Pebbly Sands " of Suffolk to those of Norfolk. ... 119 

 Mr. W. Whitaker on a Deep Channel of Drift in the 



Valley of the Cam, Essex 121 



Prof. J. ¥. Blake on the Monian and Basal Cambrian 



Rocks of Shropshire 122 



Mr. E. Rutley on Composite SpherulitesSn Obsidian from 



Hot Springs, near Little Lake, California 123 



Mr. W. S. Gresley on Quaternary Glacial-Epoch Morainic 

 Deposits of Pennsylvania 124 



