By comparing Biedma’s report with the Portuguese Relation, I am convinced that the brigantines did not pass down the Mississippi to its delta, but went out to the Gulf of Mexico by way of the Bayou Manchac, Lakes Maurepas, Pontchartrain and Borgne, and Mississippi Sound. In other words, Moscoso, with his squadron, took the same passage that Pineda had taken, in 1519, for his entering the Mississippi. Several points in the two narratives need now to be explained in detail, as to their harmony with this conclusion. First, the Indians had villages near the Bayou Manchac; but probably there were no inhabitants near the true mouth of the river, at the end of the delta. Second, under this view, we must regard the Portuguese statement of a division of the river, into two arms or branches, as referring to the large outflow, at a time of flood, to the Atchafalaya River. Instead of receiving an inflow at the junction of the Red River, the flooded Mississippi there sent out a portion of its current, by the mouth of the Red, to the Atchafalaya; which also, when the Red is at a higher stage than the Mississippi, takes a part of the current of the former, carrying it south by a much shorter course to the Gulf. Third, another statement of the Relation, noting the great depth of forty fathoms where their branch of the river “enters the sea,” must be then interpreted as found in the bend of the Mississippi from which the Bayou Manchac flows away. In its condition of a high flood, the river there opens toward a vast expanse of water, called, by the narrator, “the sea,” reaching east over Lake Maurepas and onward to the Gulf. It seems indeed not unlikely that the Mississippi at that place may have then had even so great a depth; for in a sharp curve at New Orleans it was once found by the Mississippi River Commission to have a sounding of 208 feet. On the large scale maps recently published by the Commission, the maximum depth of the river close to the departure of the Bayou Manchac is noted as 145 feet; and in the sharp bend in the east part of New Orleans, 188 feet.