Every one of them has been ridiculed as an impracticable and useless innovation in its turn.

Three of them have already been adopted, and virtually incorporated with agricultural science and economy; and the fourth, or irrigation by steam power, bids fair to find as much favor, and as many adherents in the end as the others have done.
He has not only originated these improvements, or been the first to give them practical experiment, but he has laid down certain principles which will doubtless exercise much influence in shaping the industrial economy of agriculture hereafter in different countries.

One of the best of these principles he puts in the form of a mathematical proposition.

Thus:--As the meat is to the manure, so is the crop to the land.

Tell me, he says, how much meat you make, and I will tell you how much corn you make, to the acre.
Meat, then, is the starting point with him; the basis of his annual production, to which he looks for a satisfactory decision of his balance-sheet.