The explorers were now constantly in full view of the Rocky Mountain, on which, however, their present title had not then been conferred.

Under date of July 2, the journal says:-- "The mosquitoes are uncommonly troublesome.

The wind was again high from the southwest.

These winds are in fact always the coldest and most violent which we experience, and the hypothesis which we have formed on that subject is, that the air, coming in contact with the Snowy Mountains, immediately becomes chilled and condensed, and being thus rendered heavier than the air below, it descends into the rarefied air below, or into the vacuum formed by the constant action of the sun on the open unsheltered plains.

The clouds rise suddenly near these mountains, and distribute their contents partially over the neighboring plains.