The air was keen the next morning at sunrise, the thermometer standing at 44 deg., and it was sufficiently cold to make overcoats very comfortable. A few miles brought us into the midst of the buffalo, swarming in immense numbers over the plains, where they had left scarcely a blade of grass standing. Mr. Preuss, who was sketching at a little distance in the rear, had at first noted them as large groves of timber. In the sight of such a mass of life, the traveler feels a strange emotion of grandeur. We had heard from a distance a dull and confused murmuring, and, when we came in view of their dark masses, there was not one among us who did not feel his heart beat quicker. It was the early part of the day, when the herds are feeding; and everywhere they were in motion. Here and there a huge old bull was rolling in the grass, and clouds of dust rose in the air from various parts of the bands, each the scene of some obstinate fight. Indians and buffalo make the poetry and life of the prairie, and our camp was full of their exhilaration. In place of the quiet monotony of the march, relieved only by the cracking of the whip, and an "avance donc! enfant de garce!" shouts and songs resounded from every part of the line, and our evening camp was always the commencement of a feast, which terminated only with our departure on the following morning. At any time of the night might be seen pieces of the most delicate and choicest meat, roasting _en appolas_, on sticks around the fire, and the guard were never without company. With pleasant weather and no enemy to fear, an abundance of the most excellent meat, and no scarcity of bread or tobacco, they were enjoying the oasis of a voyageur's life. Three cows were killed to-day. Kit Carson had shot one, and was continuing the chase in the midst of another herd, when his horse fell headlong, but sprang up and joined the flying band. Though considerably hurt, he had the good fortune to break no bones; and Maxwell, who was mounted on a fleet hunter, captured the runaway after a hard chase. He was on the point of shooting him, to avoid the loss of his bridle, (a handsomely mounted Spanish one,) when he found that his horse was able to come up with him. Animals are frequently lost in this way; and it is necessary to keep close watch over them, in the vicinity of the buffalo, in the midst of which they scour off to the plains, and are rarely retaken. One of our mules took a sudden freak into his head, and joined a neighboring band to-day. As we were not in a condition to lose horses, I sent several men in pursuit, and remained in camp, in the hope of recovering him; but lost the afternoon to no purpose, as we did not see him again. Astronomical observations placed us in longitude 100 deg. 05' 47", latitude 40 deg. 49' 55" JULY.