In Senate of the United States. September 5, 1850. Submitted, and ordered to be printed, and that 2,000 additional copies be printed for the use of the Senate. Mr. Underwood made the following report: The select committee to whom was referred the memorial of Charles Ellet, Jr., civil engineer, asking for an appropriation of funds to be applied to the improvement of the navigation of the Ohio River, by constructing reservoirs on its tributary streams, submit the following report