Description of Artificial Mounds in Louisiana. 39 
fectly, by Sir William Dunbar, in a published account of his ex- 
plorations of the Ouachita in 1804, under the instructions of Mr. 
Jefferson, as also by myself in the Concordia Intelligencer of 
June, 1842. Both are from observations without measurements. 
The levelling hand of American industry is fast obliterating these 
dumb, yet eloquent records of the past; and hence the necessity 
of early attention and accurate description. 
Prairie Jefferson is a tract of very fertile diluvial land, situated 
‘in the southeast part of Moorhouse parish, Louisiana, near to the 
Boeuff river, an eastern tributary of the Ouachita, some twenty 
five miles northeast from Monroe. It lies within the grant of 
and made by the Spanish government to the Baron de Bastrop; 
the same to which Aaron Burr is supposed to have been making 
his way, in his southern expedition. Near the southwestern ex- 
tremity of the prairie, and partly in what is woodland at present, 
we find the works delineated in the topographic sketch below. 
It is probable that the whole area of the works was then prairie, 
as there are no forests that bear the mark of great antiquity ; and 
as the whole diluvial surface must have been, at no very remote 
date, (geologically speaking,) destitute of forests. There are no 
streams of water nearer to this prairie than about five miles, and 
hence the necessity, with a dense population, of resorting to the 
making of artificial ponds. Accordingly the excavations, usually 
made without apparent design in constructing the mounds, are 
at this place so economized as to produce the ponds in the imme- 
diate neighborhood. Then the conformation of the surrounding 
lands, which are very gently undulating, rendered it easy to con- 
struct large ponds or lakes, to contain a perennial supply of water. 
This has plainly been the object of the extensive leveés, or em- 
bankments traced in the map. The general inclination of the 
land is southward, and the drains or wakes in the land, were 
with some skill called into aid. Generally, however, we find 
little to admire in the way of design or economy of labor. 
The mound at A, termed ‘the Temple,” from the supposi- 
tion that it was the place of worship and sacrificial fires, is about 
fifty feet in height, with steep faces on every side, and accessible 
only by the causeway, which is a winding road on the southeast 
face, at ‘‘a.” Its base covers a square of about fifty yards, and 
its summit, one of fifteen yards. All its angles are very much 
rounded, still it has the four faces very plainly marked. Since 
