SOURCE OF ST. Peter's river. 35 



iiig within a short distance of the Grand or Red Fork of Red 

 river, Mr. Colhoun took an observation for longitude on 

 the banks of that river. The result was that we were in 

 longitude 96° 53' 45" west, and our latitude a few miles 

 beyond this, at the foixling of the Red Fork, was 47° 

 47' 25". This branch was forty yards wide where we forded 

 it ; from the steepness of the banks we experienced some 

 difficulty in getting our carts over. Its bed is sandy, and 

 its current very rapid. On the 2d of August we suffered 

 much from cold. The thermometer, which had stood at 83° 

 the preceding day at noon in the shade, had sunk to 43° at 

 sunrise. This variation was greater than any we had as yet 

 observed, but for a number of days previous, the variation 

 from sunrise to noon averaged 30°. The transition from 

 great heat during the day to very cold nights was extremely 

 unpleasant; it produced very copious dews, much heavier 

 than any we had ever experienced. We were upon prairies, 

 unsheltered by any tree, and from our mode of travelling 

 very much exposed ; frequently our clothes were as wet 

 as if they had been soaked in water ; this was one of the 

 circumstances that made the mounting guard at night so 

 arduous a duty both to the soldiers and gentlemen. 



We had an opportunity of observing while travelling 

 upon these prairies the long twilight nights which charac- 

 terize high latitudes. We had scarcely more than five 

 hours of night, and as the moon was at that time pretty 

 full, we seldom experienced any darkness during the 

 whole of our journey to Pembina. 



There were numerous ponds of stagnant water upon 

 these prairies, in one of which a beaver was seen, but at 

 too great a distance to be shot at ; in the vicinity Mr. Scott 

 killed a line-tailed squirrel* which Mr. Say prepared ; it 



* Sclurus grarrmui'us, (Say,) Account of an ExppdHion to the Rc^cky 

 Mountains, vol. 2 p. 72. 



