I thank you for the pamphlet containing your ideas on the subject of canals constructed of wood; but it is not in my power to give any definite opinion of it’s national importance. if there exists a cement which used as a lining for cisterns & aquaeducts renders them impermeable to water, (and it is affirmed that in France they are in the possession and use of such an one), then it becomes the common question whether constructions of wood, brick or rough stone are cheapest in the end? a question on which every man possesses materials for forming his judgment. I suspect it is the supposed necessity of using hewnstone in works of this kind which has had the greatest effect in discouraging their being undertaken. I tender you my salutations & respects.