I 415 ] 



eaftefn and fouthern parts of Ruffia, and may have been derived 

 from latitude 55° and longitude 40^, and originated on the At- 

 lantic, lat. 40°, and hence the utmoft rigour of this cold was 

 fooner perceived in the fouth of France, as Tholoufe, Marfeiiles, 

 &c. than in the more northern latitudes, as may be feen in Van- 

 Swinden's general table, for it reached thefe towns on the i8th 

 or 19th of January. In the more northern latitudes it was felt 

 only on the 27th ; it is true its date at St. Jean de Luz, latitude 

 43°, is January 28th in the general table, but this is a mifiake, 

 as may be feen, p. iSr, for January 19th is there faid to be the 

 true date, and, p. 179, it is faid that the iSth or rgth of January 

 are the days on which the greateft cold was obferved in all places 

 fouth of the Garonne ; which fully confirms my former flatement 

 that the wind which produced this cold originated in the fouth- 

 weft, and thence was gradually propagated northwards and eaft- 

 wards. All the minuter modifications of this cold, in places not 

 very diftant from each other, may be afcribed either to recent 

 falls of fnow, the proximity to which muft efted more or lefs 

 the thermometers, the greater or lefTer abundance of vapours in 

 the atmofphere, and other circumftances too tedious and minute 

 for infertion in this general view. 



Snow falling from fome height in the atmofphere is generally 

 for fome time furrounded with an atmofphere much colder than 



3 F 2 the 



