J. Madison presents his respectful compliments to the President & returns the Treatise on small Canals &c, with his acknowledgments for the perusal of it.1 He is not enough conversant with such subjects to decide on the merits of the various plans & machinery recommended by the Author. In general his principles appear to be both effective & practicable; but the question of their utility must be decided by a very accurate comparison of expence & saving, which can not easily be made without partial experiments at least; and which must vary also in different countries, & different situations of Society. The author however is certainly entitled to much praise for his ingenuity & laudable zeal for improvement; and has probably by his work really contributed to it, either immediately, or by the use that may be made of his ideas by others.