cations the whole cultivated ground with the means of irrigation. How quick this sandy, apparently sterile soil in the valley of the Rio del Norte is by affluence of water changed into the most fertile, is astonishing; and the granitic character of the surrounding mountains, whose decomposed parts are carried into the valley and form a portion of its soil, may have some influence upon it, as it is well known how much decomposed granite, and principally decomposed feldspar, favors vegetation; but, for its complete decomposition it requires more water than the climate affords by rain.
On July 15, at last I discovered from the top of the house, my usual observatory, the approach of the caravan. They had been detained, as I supposed, by the falling of rains, which made part of the road along the river nearly impassible. Riding up, I found them in the worst king of miry bottom, and it took them one day and a half to reach from here a higher and better road running east of Albuquerque. As I had left my barometer and other instruments in the wagon, it was not in my power to make an observation for elevation above the sea since my excursion to the gold mines. The place at which I had made the first observation again was about three miles north of Albuquerque, in a level plain about one mile east of the Rio del Norte, and it resulted in 4,813 feet elevation above the sea. Santa Fe I had found to be elevated 7,047 feet. The usual road from there, by Agua Fria and Algodones, to Albuquerque, does not amount to more than 63 miles. In about two thirds of this distance the road descends towards the river, and in the last third it leads along the river, through its valley. The descent, therefore, from Santa Fe to the Rio del Norte (a distance of about 40 miles on this road) must be very rapid, as it amounts to about 2,200 feet.
July 17.–Weather and road improved to-day. We passed Albuquerque this morning and halted two miles beyond, at Sandival's hacienda. We had taken the upper eastern road, which was very sandy, but drier. From here, advised so by Mexicans, we intended also to take a higher road, leading over the hills; but when we arrived in the evening at the height of the hills, after a good deal of trouble, the road some distance ahead was found impracticable. We had to camp here in a sandy plain, covered with artemisia and similar shrubbery, but without grass.
July 18.–Commenced this morning with a retreat to Sandival's hacienda, and travelled then on the usual road along the river three miles further before we camped. Some of the wagons got again mired, and prevented us from going any further. Our camp was close to the river, and on its left bank. Some caravans prefer to cross the river at Albuquerque, and recross it again near Socorro, but we thought it best to continue always along the left bank. The Rio del Norte is here about 100 yards wide, and, as usual, sandy, shallow, everywhere fordable and nowhere navigable, not even for canoes. In the river we saw an abundance of geese, ducks, and pelicans; the latter bird is very common all along the water. Fishes and shells appear to be very scarce. On the banks of the river, heretofore quite bare of trees, occasionally a few cotton trees are seen. West of the river rise light hills, while east of it, in the distance of 10 miles, a rugged chain of granitic mountains confines the valley. Vegetation, except on the water course, is poor, the soil generally sandy and dry. Everywhere in the sandy regions of New Mexico most various kinds of lizards are seen, but their swiftness makes it very difficult to catch them.
