increase is not regular. At times the water will fall four or five feet, and then rise again. The flood maintains its greatest height about a week or ten days, and then gradually subsides, till the river is reduced to its usual depth. By spreading over the flat lands a rich coating of leaves, decayed vegetables, and loam, washed down by the rain from the sides of the hills, these inundations greatly promote the fertility of the soil.
Fort Fayette, built a few years since, is within the limits of the town of Pittsburg. It is erected on the banks of the Alleghany. At present a garrison is kept there, which, for the most part, is made head-quarters of the United States army.[29]
The high ground back of the fort, called "Grant's hill," commands a most extensive prospect, taking in a view of the two rivers {45} for several miles above and below their junction.[30]
The inhabitants use the water of the river here and down the Ohio for drink and cookery, even in preference to the spring water from the hills; for as yet they have not practised the digging of wells. At first we were surprised at this preference; but they assured us that the river water was more wholesome and generally much more palatable. We were soon convinced that this must be the case: for, though the river water receives a great deal of decayed wood, leaves, &c. from the creeks and runs that empty into it, they are soon deposited on the shallows, and the deeper places are very clear and fine. Even the turbid
