CONTENTS OF VOL. XXVII. 



(FIETH SEEIES). 



NTJMBEE CLXIV.— JANUAET 1889. 



Page 



Prof. S. P. Langley on Energy and Vision 1 



Prof. J. A. Eleming's Design for a Standard of Electrical 

 Resistance. (Plate I.) 24 



Mr. E. J. Smith on a Continuous Heat and Electrical-Current 

 Measuring-Instrument 28 



Mr. 0. Heaviside on the General Solution of Maxwell's Elec- 

 tromagnetic Equations in a Hoinogeneous Isotropic Medium, 

 especially in regard to the Derivation of Special Solutions, 

 and the Formulae for Plane Waves 29 



Eev. T. Pelham Dale on the Upper Limit of Eefraction in 

 Selenium and Bromine 50 



Prof. J. Y. Jones on the Calculation of the Coefficient of 

 Mutual Induction of a Circle and a Coaxal Helix 56 



Capt. W. de W. Abney on the Measurement of the Lumi- 

 nosity and Intensity of Light reflected from Coloured 

 Surfaces , . . 62 



Dr. J. W. W. Waghorn on a Modification of the Ordinary 

 Method of Determining Electromagnetic Capacity 69 



Mr. J. Parker on Thermoelectric Phenomena 72 



Proceedings of the Geological Society : — 



Mr. H.T. Brown on the Permian Eocks of the Leicester- 

 shire Coal-field 74 



Mr. J. B. Tyrrell on the Superficial Geology of the Central 



Plateau of North-western Canada 76 



Mr. W. Whittaker on the Deep Boring at Streatham . . 77 



On the Excitation of Electricity by the Contact of Earefied 

 Gases with Galvanic Incandescent Wires, by J. Elster and 

 H. Geitel 78 



On the Physical Properties of Thin Solid Laminae, by G. 

 Quincke 79 



