In considering the effect of drainage on streams and rivers, it appears that the results of such operations, so far as they can be appreciated, are, to lessen the value of water powers, by increasing the flow of water in times of freshets, and lessening it in times of drought. It is supposed in this country, that clearing the land of timber has sensibly affected the value of "mill privileges," by increasing evaporation, and diminishing the streams. No mill-owner has been hardy enough to contend that a land-owner may not legally cut down his own timber, whatever the effect on the streams. So, we trust, no court will ever be found, which will restrict the land-owner in the highest culture of his soil, because his drainage may affect the capacity of a mill-stream to turn the water-wheels.

To return from our digression. It is necessary, in order to a correct apprehension of the work which our drains have to perform, to form a correct opinion as to how much of the surplus moisture in our field is due to each of the three causes to which we have referred—to wit, rain-water, which falls upon it; springs, which burst up from below; and water of pressure, stagnant in, or slowly percolating through it. The rain-tables will give us information as to the first; but as to the others, we must form our opinion from the structure of the earth around us, and observation upon the field itself, by its natural phenomena and by opening test-holes and experimental ditches. Having gained accurate knowledge of the sources of moisture, we may then be able to form a correct opinion whether our land requires drainage, and of the aid which Nature requires to carry off the surplus water.

WHAT LANDS REQUIRE DRAINAGE?

The more one studies the subject of drainage, the less inclined will he be to deal in general statements. "Do you think it is profitable to underdrain land?" is a question a thousand times asked, and yet is a question that admits of no direct general answer. Is it profitable to fence land? is it profitable to plow land? are questions of much the same character. The answers to them all depend upon circumstances. There is land that may be profitably drained, and fenced, and plowed, and there is a great deal that had better be let alone. Whether draining is profitable or not, depends on the value and character of the land in question, as well as on its condition as to water. Where good land is worth one hundred dollars an acre, it might be profitably drained; when, if the same land were worth but the Government price of $1.25 an acre, it might be better to make a new purchase in the neighborhood, than to expend ten times its value on a tract that cannot be worth the cost of the operation. Drainage is an expensive operation, requiring much labor and capital, and not to be thought of in a pioneer settlement by individual emigrants. It comes after clearing, after the building of log-houses and mills, and schoolhouses, and churches, and roads, when capital and labor are abundant, and when the good lands, nature-drained, have been all taken up.

And, again, whether drainage is profitable, depends not only on the value, but on the character of the soil as to productiveness when drained. There is much land that would be improved by drainage, that cannot be profitably drained. It would improve almost any land in New England to apply to it a hundred loads of stable manure to the acre; but whether such application would be profitable, must depend upon the returns to be derived from it. Horace Greeley, who has his perceptions of common affairs, and especially of all that relates to progress, wide awake, said, in an address at Peekskill, N. Y.:

"My deliberate judgment is, that all lands which are worth plowing, which is not the case with all lands that are plowed, would be improved by draining; but I know that our farmers are neither able nor ready to drain to that extent, nor do I insist that it would pay while land is so cheap, and labor and tile so dear as at present. Ultimately, I believe, we shall tile-drain nearly all our level, or moderately sloping lands, that are worth cultivation."

Whether land would be improved by drainage, is one question, and whether the operation will pay, is quite another. The question whether it will pay, depends on the value of the land before drainage, the cost of the operation, and the value of the land when completed. And the cost of the operation includes always, not only the money and labor expended in it, but also the loss to other land of the owner, by diverting from it the capital which would otherwise be applied to it. Where labor and capital are limited so closely as they are in all our new States, it is a question not only how can they be profitably applied, but how can they be most profitably applied. A proprietor, who has money to loan at six per cent. interest, may well invest it in draining his land; when a working man, who is paying twelve per cent. interest for all the capital he employs, might ruin himself by making the same improvement.

DO ALL LANDS REQUIRE DRAINAGE?

Our opinion is, that a great deal of land does not in any sense require drainage, and we should differ with Mr. Greeley, in the opinion that all lands worth ploughing, would be improved by drainage. Nature has herself thoroughly drained a large proportion of the soil. There is a great deal of finely-cultivated land in England, renting at from five to ten dollars per acre, that is thought there to require no drainage.