398 



height of 



Prof. Hull on the extraordmary darkness of Nov. 1819. 



before tlie country is settled in their vicinity, grows to the, 



six or seven feet."* This vegetation, another writer ob- 



becomes sufficiently dry to burn during the long dry sea- 



which commences usually in 



son, called the Indian Summer 



October, and continues a month and a half or two months 

 which the vegetation is killed by the frost and dried by 



the w^t prairies are also dried, and before th 



has expired 



the grass is perfectly combustible.^f In order the more easily to 



take their game, and to facilitate 



elling from one hunting 



ground to another, the Indians, we are informed, occasionally set fire 

 to the Prairies " towards the close of the Indian sui 



I 



* See Atwater's Letters to Professor Silliman on the Prj 

 published in « The American Journal of Science," v. i. p. 116. 



t See R. W. Wells' communication on prairies, published in the same work, 



V. i. p. S34, 



West. 



i 





\ 



