Rocky Mountains. 489 



15'. There were a few broken cumulo-stratose clouds from 

 the southwest, otherwise the sky was clear, and near the 

 Zenith, where the star was seen, of a deep and beautiful 

 azure. Our actual elevation, at this time, must have been 

 considerable, and might be supposed to effect, in some de- 

 gree, the transparency of our atmosphere. 



Several magpies were seen about the islands in the river, 

 where it is probable they rear their young. 



On the 30th we left the encampment at our accustomed 

 early hour, and at 8 o'clock were cheered by a distant 

 view of the Rocky Mountains. For some time we were 

 unable to decide whether what we saw were mountains, or 

 banks of cumulous clouds skirting the horizon, and glitter- 

 ing in the reflected rays of the sun. It was only by watching 

 the bright parts, and observing that their form and position 

 remained unaltered, that we were able to satisfy ourselves, 

 they were indeed mountains. They were visible from the 

 lowest parts of the plain, and their summits were, when first 

 discovered, several degrees above our horizon. They became 

 visible by detaching themselves from the sky beyond, and 

 not by emerging from beneath the sensible horizon, so that 

 we might have seen them from a greater distance had it not 

 been for the want of transparency in the atmosphere. Our 

 first views of the mountains were indistinct, on account of 

 some smokiness of the atmosphere, but from our encamp- 

 ment, at noon, we had a very distinct and satisfactory pros- 

 pect of them. A small part only of the intervening plain was 

 visible, the convexity of the surface intercepting the view, 

 from the base of the mountains, and that portion of the 

 plain adjacent to it. 



Snow could be seen on every part of them which was visi- 

 ble above our horizon. 



The thermometer immersed in the water of the river fell 

 from 80° the temperature of the atmosphere, to 75°. Ob- 

 servations had been made daily to ascertain the temperature 



vol. i. 62 



