"In a subsoil that is impervious to water, either by being a red clay, blue clay, or hard-pan, within a foot of the surface, I would recommend farmers to feel their way very cautiously in draining. If tiles and labor were as low here as in Great Britain, we could afford to make drains sixteen feet apart in such land, and then, by loosening the soil, say twenty inches deep, by the subsoil plow, I think such land might be made perfectly dry; but I don't think the time is yet come, considering the cost of tiles and labor, to undertake such an outlay; but still it might pay _in the end_. I have found only a little of red clay subsoil in draining my farm. I never had any blue clay on my farm, or hard-pan, to trouble me; but I can readily perceive that it must be equally bad to drain as the tenacious red clay. If I were going to purchase another farm, I would look a great deal more to the subsoil than the surface soil. If the subsoil is right, the surface soil, I think, cannot be wrong." In the same paper, under date of July 8th, Mr. Johnston says, "The only experience I have had in digging into soils, to judge of draining out of this county (Seneca), was in Niagara." He states the result of his observations thus: "A few inches below the surface I found a stiff blue clay for about ten inches deep, and as impervious to water as so much iron. Underneath that blue clay, I found a red clay, apparently impervious to water; but, as water could not get through the blue, I could only guess at that; and, after spending the greater part of the day, with five men digging holes from four to five feet deep, I found I knew no more how such land could be drained, than a man who had never seen a drain dug. I advised the gentleman to try a few experiments, by digging a few ditches, as I laid them out, and plowing as deep as possible with a subsoil plow, but to get no tile until he saw if he could get a run of water. He paid my traveling expenses, treated me very kindly and I have heard nothing from him since. "Now, if your correspondent's soil and subsoil is similar to that soil I would advise him to feel his way cautiously in draining. Certainly, no man would be fool enough to dig ditches and lay tile, if there is no water to carry off." In the _Country Gentleman_ of Nov. 18th, 1858, we find an interesting statement, by John S. Pettibone, of Manchester, Vermont, partly in reply to the statement of Mr. Johnston. The experiment by Mr. Pettibone, showing the increased permeability of clay, merely by the passage of water through it, is very interesting. He says, in his letter to the editor: