383 Dr. blagden’s WJlory of 
mountains may be one fource of the exceffive cold which par- 
ticular winds occafion in North America. But another cir- 
cumftance is to be taken into consideration, that when the fury 
of thefe N.W. winds abates, they very regularly draw round to 
the weft ward and fouthward. Now the maximum of cold muff 
be, when the cold wind has blown as long as it can, and the 
lucceeding warmer wind has not yet had time to undo any of 
its effedf ; confequently at the period when it is veering round 
from the northward toward the fun. Accordingly we find, 
that when the cold has become fufficiently great at Albany 
Fort to congeal quicklilver, the wind not only came 
from the fouthward of W. but commonly, alfo, blew with 
very little force ; indeed the intenfeft frofts in all countries feem 
to take place with light airs or a calm. 
/ 
§ 9. There are, in the poffeffion of the Royal Society, fe- 
veral other meteorological regifters from our different fettle - 
ments on Hudfon’s Bay ; but none of thofe which I have feen 
contain any linking extraordinary appearances, to fhew that 
the thermometer was frozen ; and the defcent alone, within 
certain bounds, determines nothing, for thefe inftruments were 
formerly conftructed with fo little accuracy, as to be often 
marked 8 or 10 degrees too low at the point of mercurial con- 
gelation. I conclude, therefore, that when Meff. wales and 
dymond were at Prince of Wales’s Fort in the winter of 
1768 and 1769, the quickfilver always retained its fluidity, 
though it once funk to -45 0 of their thermometer*. This 
Fort lies in lat. 59 0 ; but on account of the abovemen tioned 
ridges of mountains, and perhaps for other caufes, the fouthern 
parts of the Bay may be quite as cold as the northern. 
'*• Phil. Tranfadl, vol, LX. p. 153. 
§ IO. 
