.350 BAROMETER. 



is also very great, as the thermometer often rises 

 to 90 in September and October, during the 

 hottest part of the day, and falls below 32 at 

 night, making the daily range of temperature 

 60 F. 



Still more extraordinary are the changes from 

 heat to cold in those extensive regions of North 

 America beyond the limits of the United States, 

 which have been explored by Scoresby, Parry, 

 Franklin, Ross, and other British navigators. 

 We are informed by Captain Back, that on the 

 17th of January, 1834, the thermometer stood 

 70 F. at 6 A. M. on the Great Slave Lake, 

 lat. 62 46' ; but rose to 45 in the afternoon of the 

 same day, making a diurnal range of 1 15. He 

 also states, that on the preceding day, the tem- 

 perature rose to 52 ; while the long summer days 

 were often oppressively warm. Hence it is, that 

 as we approach the polar regions, we find the 

 winds so irregular and variable, coinciding with 



that is, from 11 to 90. Hence it is, that the mean range of 

 the barometer is about the same in Great Britain that it is in the 

 middle States of America, as observed by Dr. Dalton forty years 

 ago. Perhaps there is no part of the world where the fluctua- 

 tions of temperature are more frequent than in England; the 

 reason of which is obvious from its insular and geographical 

 position, being situated about midway between the burning 

 plains of Africa to the south, and the frozen regions of the 

 north ; while on the east and north east it is influenced by Sweden, 

 Poland, Russia, and the cold elevated plains of Tartary ; and 

 by the Atlantic ocean on the west ; all of which contribute their 

 share successively in forming the climate of Britain. 



