CONTENTS OF VOL. XXIII 



(FOURTH SERIES.) 



NUMBER CLI.— JANUARY 1862. 



Page 



Archdeacon Pratt on Chinese Astronomical Epochs * 1 



Prof. Marcet on the Comparative Effects of Nocturnal Radiation 

 from the Surface of the Ground and over a large Sheet of 

 Water 9 



Prof. Maxwell on Physical Lines of Force 12 



The Astronomer Royal on the Direction of the Joints in the 

 Faces of Oblique Arches 24 



M. G. Kirchhoff on the Relation of the Lateral Contraction to 

 the Longitudinal Expansion in Rods of Spring Steel. (With 

 a Plate.) . .. 28 



The Rev. S. Haughton's Notes on Mineralogy . < . . i ..*... . 47 



Prof. Potter on the Fourth Law of the Relations of the Elastic 

 Force, Density, and Temperature in Gases 52 



Prof. Roscoe on the Solar Spectrum, and the Spectra of the 

 Chemical Elements 63 



Sir R. I. Murchison on the inapplicability of the new term 

 " Dyas " to the " Permian " Group of Rocks, as proposed by 

 Dr. Geinitz 65 



Notices respecting New Books: — Mr. R. Potts's Euclid's 

 Elements of Geometry, designed for the use of the higher 

 Forms in Public Schools and Students in the Universities . . 70 



Proceedings of the Royal Society : — 



The Rev. H. Moseley on the Motion of a Plate of Metal 

 on an Inclined Plane, when dilated and contracted ; and 

 on the descent of Glaciers. 72 



On the Conductibility of Saline Solutions, by M. Marie-Davy. 79 



NUMBER CLII.— -FEBRUARY. 



Drs. Russell and Matthiessen on the Cause of Vesicular Struc- 

 ture in Copper 81 



Prof. Maxwell on Physical Lines of Force 85 



Mr. A. H. Church on the Composition, Structure, and Forma- 

 tion of Beekite. (With a Plate.) 95 



Prof. Regnault on the Specific Heat of some Simple Bodies. 

 (With a Plate.) 103 



