PREFACE. XI 



St. Anthony the thermometer was exposed to the south- 

 west; at other posts, we have seen it facing the east; 

 sometimes the instruments were protected from, at other 

 times they were exposed to, the rays of the sun : there 

 can be no doubt that some variations must arise from these 

 causes; and we think it therefore desirable, in order to 

 give the greatest value to the observations made at all the 

 garrisons in the United States, that the surgeons should be 

 provided, at the public expense, with instruments of uni- 

 form and approved construction; and that the observations 

 should be made under circumstances as nearly similar as 

 the great diversity in the situations of their posts will ad- 

 mit. Notwithstanding the variations produced by the 

 causes to which we have alluded, we consider these tables 

 as being very interesting, inasmuch as they afford the first 

 comparative results upon the temperature of the United 

 States in general, embracing an immense extent of coun- 

 try, and including great diversities of climate. 



We deem it but fair to state that the observations which 

 Messrs. Say and Keating made, concerning the manners, 

 &c. of the Indian tribes which they met, were greatly fa- 

 cilitated by the valuable notes furnished to them by the 

 American Philosophical Society, and which were chiefly 

 prepared by Peter S. Duponceau, Esquire, one of the Vice 

 Presidents of the Society, Professor Robert Walsh, jun. one 

 of the Secretaries, and by Dr. Samuel Brown,* Professor of 

 the Practice of Physic in the Transylvania University. 



* The undersigned begs leave to state, that Dr. Brown's name was 

 inadvertently omitted in the Preface to the " Account of an Expedi- 

 tion from Pittsburgh to the Rocky Mountains." The gentlemen of that 

 party were provided with the same notes which were used on the se- 

 cond expedition, and which were in both cases found very valuable. 



T. SAY. 



