the measure of the goodness and permanence of the whole drain_, just as the weakest link of a chain is the measure of its strength." The simple laying of the smaller sizes of pipes and collars in the lateral drains, is an easy matter. It requires care and precision in placing the collar equally under the end of each pipe, (having the joint at the middle of the collar,) in having the ends of the pipes actually touch each other within the collars, and in brushing away any loose dirt which may have fallen on the spot on which the collar is to rest. The connection of the laterals with the mains, the laying of the larger sizes of tiles so as to form a close joint, the wedging of these larger tiles firmly into their places, and the trimming which is necessary in going around sharp curves, and in putting in the shorter pieces which are needed to fill out the exact length of the drain, demand more skill and judgment than are often found in the common ditcher. Still, any clever workman, who has a careful habit, may easily be taught all that is necessary; and until he is thoroughly taught,—and not only knows how to do the work well, but, also, understands the importance of doing it well,—the proprietor should carefully watch the laying of every piece. _Never have tiles laid by the rod, but always by the day._ "The more haste, the less speed," is a maxim which applies especially to tile-laying. If the proprietor or the engineer does not overlook the laying of each tile as it is done, and probably he will not, he should carefully inspect every piece before it is covered. It is well to walk along the ditches and touch each tile with the end of a light rod, in such a way as to see whether it is firm enough in its position not to be displaced by the earth which will fall upon it in filling the ditches.