and whose inventive genius has led to many im- 

 provements on them. I need only remark, that he 

 has made nearly the whole instruments which were 

 used hy our late highly distinguished Professor of 

 Natural Philosophy, Sir John Leslie, as also those 

 used hy Sir David Brewster, in his experiments on 

 Natural Philosophy, and more particularly such as 

 were connected with his admirable discoveries con- 

 cerning the polarization of light. 



When Travellers and Naturalists go into foreign 

 lands, or even traverse the more remote districts of 

 Britain, or the continent of Europe, they should not 

 confine their researches to the collecting of natural 

 objects alone ; their attention should be extended to 

 geographical and meteorological observations, the 

 altitude of mountains, lakes, and sources of rivers, 

 above the level of the sea ; the moisture and parti- 

 cular state of the atmosphere in those situations ; 

 the temperature of hot springs ; their relation to 

 volcanic causes : for all which purposes instruments 

 are made, by which these things can be easily de- 

 termined. 



On these interesting points, much yet remains to 

 be done even in Great Britain. 



T. B. 



