CONTENTS OF VOL. XXXIV. 



(THIRD SERIES.) 



NUMBER CCXXVL—JANUARY 1849. 



Page 

 Mr. J. H. Alexander on a new Empirical Formula for ascertain- 

 ing the Tension of Vapour of Water at any Temperature . . 1 



Mr. J. Brown on the Products of the Soda Manufacture 15 



Mr. J. Cockle on a new Imaginary in Algebra 37 



Mr. W. Pringle on the Continuance of a Solar Spot 48 



The Rev. J. M. Heath on a simple Rule for converting intervals 

 of Sidereal into intervals of Mean Solar Time, and vice versa, 



without the help of Tables 51 



Mr. G. G. Stokes on some Points in the received Theory of 



Sound 52 



The Rev. C. Graves on the Calculus of Operations 60 



Proceedings of the Royal Astronomical Society 63 



Royal Society 73 



On a new Modification of Phosphorus, by M. Schroetter .... 78 



Meteorological Observations for November 1848 79 



Meteorological Observations made by Mr. Thompson at the 

 Garden of the Horticultural Society at Chiswick, near 

 London ; by Mr. Veall at Boston ; by the Rev. W. Dunbar at 

 Applegarth Manse, Dumfries-shire; and by the Rev. C. 

 Clouston at Sandwick Manse^ Orkney 80 



NUMBER CCXXVII.— FEBRUARY. 



H. C. CErsted's Experiments on Diamagnetism 81 



The Rev. J. Challis's Continuation of Researches in the Ma- 

 thematical Theory of Aerial Vibrations 88 



Mr. J. H. Alexander on a new Empirical Formula for ascertain- 

 ing the Tension of Vapour of Water at any Temperature 

 {concluded) 98 



Prof. J. R. Young on the Remainder of the Series in the deve- 

 lopment of (1-f a;)-'*, and on a Theorem respecting the pro- 

 ducts of Squares 113 



Dr. R. A. Smith on a Mode of rendering Substances incom- 

 bustible 116 



a2 



If 



