the sources of these springs, and lead their water harmlessly away. Gisborne, one of the best agricultural writers of England, put the case tersely and well when--objecting to the system of circumventing springs--he said, "_Hit him straight in the eye_, is as good a maxim in draining as in pugilism." It is best not to pass up at the side of a spring, and so creep around behind it to head off its water; but to drive the drain straight through it, and far enough beyond it to tap and lead away at a lower level the water which causes it. These drains, as well as all others intended simply to remove subsoil water, and not to cut off a weeping stream, are best made with common drain-tiles laid as before directed, and covered immediately with well-packed earth. Water enters an under-drain, not from above, but from below; that is to say, as water, from whatever source, fills the subsoil, it rises therein until it reaches the floor of the drain, when it enters and is led away, just as water falling into a cask which stands on end flows off at the under side of the bung-hole when it reaches its level. Even if the cask be filled to the top with earth, the rain falling upon it will descend perpendicularly to the bottom, and will flow off at the bung only when the soil to that level has become saturated. It will descend through the soil by the straightest course, and will raise the general level. It will not violate the laws of gravitation, and run diagonally toward the point of outlet, as seems to be the general supposition when the perplexing question, "How does water get into the drain?" is first considered. When we drive a drain through a spring and into the water-bearing stratum which feeds it, we simply make it easier for the water to escape by the drain than to keep on at the higher level, and break out at the surface of the ground. As in the case of the sidewalk illustrated in Figure 1, in cutting off a continuous weeping or ooze from higher land, it is best to introduce a vertical filling of porous material through which the water will descend and enter the drain; but, excepting this single instance, all that we need to do, so far as subterranean work is concerned, is to furnish an easy and sufficient channel for the removal of subsoil water.