557 



Lawrence, he found that the barometer as frequently rises as falls 

 under the prevalence of a strong wind ; and that the winds often 

 blow with greater force with a rising than with a falling barometer. 

 He gives a circumstantial account of the progress and course of va- 

 rious gales which fell under his observation during that period, and 

 from which he infers the existence of a steady connexion between 

 the prevailing winds of this region and the movements of the baro- 

 meter, and enters into an inquiry into the mode in which that in- 

 strument is affected by them. The extensive valley of the St. Law- 

 rence is bounded at its lower part, for a distance of nearly 500 

 miles, by ranges of hills, rising on each side to a considerable eleva- 

 tion. Within this space, the ordinary winds follow the course of the 

 river ; and in almost every instance when they approach from wind- 

 ward, the barometer rises with them ; and when, on the other hand, 

 the wind approaches from leeward, the barometer not only falls be- 

 fore the arrival of the wind, but continues to fall until it has sub- 

 sided. 



An appendix is subjoined containing extracts from the tabular re- 

 gister of the barometer and winds at various points in the valley of 

 the River St. Lawrence, during the years 1834 and 1835, accompa- 

 nied by remarks on different points deserving notice in particular 

 cases. 



" On the Elliptic Polarization of Light by reflexion from Metallic 

 Surfaces." By the Rev. Baden Powell, M.A., F.R.S., Savilian Pro- 

 fessor of Geometry in the University of Oxford. 



In a former paper, published in the Philosophical Transactions 

 for 184?3, the author gave an account of the observations he had 

 made on the phaenomena of elliptic polarization by reflexion from 

 certain metallic surfaces, but with reference only to one class of 

 comparative results. He has since pursued the inquiry into other 

 relations besides those at first contemplated, and the present paper 

 is devoted to the details of these new observations, obtained by va- 

 rying the inclination of the incident rays, and the position of the 

 plane of analysation, and by employing different metals as the re- 

 flecting surfaces. By the application of the undulatory theory of 

 light to the circumstances of the experiments and the resulting phas- 

 nomena, the law of metallic retardation is made the subject of ana- 

 lytic investigation. A polariscope of peculiar construction, of which 

 a description is given at the conclusion of the paper, was employed 

 in the experiments: and tables are subjoined of the numerical re- 

 sults of the observations. 



" On the Gas Voltaic Battery. Voltaic Action of Phosphorus, 

 Sulphur, and Hydrocarbons." By William Robert Grove, Esq., 

 M.A., F.R.S., V.P.R.I., Professor of Experimental Philosophy at 

 the London Institution. 



The author, referring to a paper of his published in the Philoso- 

 phical Transactions for 1843, states, that in repeating and verifying 

 some of the experiments therein contained, he was led to those which 



