CONTENTS. 



On the Method of the Least Squares. By J. Ivoky, Esq. M.A. 

 F.R.S 161 



On a Syphon Hydrometer, and its Use injinding the Tempera- 

 ture of Water at the greatest Density. By Mr. Henry 

 Meikle 166 



On the magnetizing Power of the more refrangible Solar Rays. 

 By Mrs. M. Somerville 168 



On the Inflammation of Gunpowder by Electricity. By Mr. 

 Thomas Howldy 173 



Atmospheric Refraction at very low Temperatures and Altitudes. 

 By J. Ivory, Esq. M.A. F.R.S 177 



On the Strength of Bone. By B. Bevan, Esq. . . . 181 



Instructions for collecting Geological Specimens. By William 

 Henry Fitton, M.D. F.R.S. V.P.G.S. . .... 182 



Notice of the volcanic Character of the Island of Hawaii, in a 

 Letter to Prffcssor Silliman, and of various Facts connected 

 with late Observations of the Christian Missionaries in that 

 Country, abstracted from a Journal of a Tour around Hawaii, 

 the largest of the Sandwich Islands 187,252 



On an Anomalous Case of Vision with regard to Colours. By 

 George Harvey, Esq. F.R.S. Ed. 205 



Account of the Descent of a Diving-Bell, newly invented by 

 T. Steele, Esq. M.A 211 



On the Velocity of Sound. By Wm. Galbraith, Esq. M.A. 



214 



On the Methods proper to be used for deducing a general 

 Formula for the Length of the Seconds Pendulum, from a 

 Number of Experiments made at different Latitudes. By 

 J. Ivory, Esq. M.A. F.R.S. .241 



Disquisition concerning the Length of the Seconds Pendulum, 

 and the Ellipticity of the Earth. By J. Ivory, Esq. M.A. 

 F.R.S 246 



On effecting Combustion by the Electric Spark. By Mr. Thomas 

 Howldy 267 



Experiments on the Strength of Cohesion of Wood. By B. Be- 

 van, Esq 269 



A Description of Barclay's Hydrostatic Quadrant, and an Ac- 

 count of Observations made with it. By Edward Riddle, 

 Esq .270 



Observations on the practical Inutility of Messrs. Yarrow and 



