9. As to irrigation, I doubt that there is a farm in the United States where _something_ might not be profitably done forthwith to secure advantage from the artificial retention and application of water. Wherever a brook or runnel crosses or skirts a farm, the question--"Can the water here running uselessly by be retained, and in due season equably diffused over some portion of this land?"--at once presents itself. One who has never looked with this now will be astonished at the facility with which some acres of nearly every farm may be irrigated. Often, a dam that need not cost $20 will suffice to hold back ten thousand barrels of water, so that it may be led off along the upper edge of a slope or glade, falling off just enough to maintain a gentle, steady current, and so providing for the application of two or three inches of water to several acres of tillage or grass just when the exigencies of crop and season most urgently require such irrigation. Any farmer east of the Hudson can tell where such an application would have doubled the crop of 1870, and precluded the hard necessity of selling or killing cattle not easily replaced. Of course, this is but a rude beginning. In time, we shall dam very considerable streams mainly to this end, and irrigate hundreds and thousands of acres from a single pond or reservoir. Wells will be sunk on plains and gentle swells now comparatively arid and sterile, and wind or steam employed to raise water into reservoirs whence wide areas of surrounding or subjacent land will be refreshed at the critical moment, and thus rendered bounteously productive. On the vast, bleak, treeless Plains of the wild West, even Artesian wells will be sunk for this purpose; and the water thus obtained will prove a source of fertility as well as refreshment, enriching the soil by the minerals which it holds in solution, and insuring bounteous crops from wide stretches of now barren and worthless desert. Immigration will yet thickly dot the great Sahara with oases of verdure and plenty; but it will, long ere that, have covered the valleys of our Great Basin and those which skirt the affluents of the savage and desolate Colorado with a beauty and thrift surpassing the dreams of poets. And yet, its easiest and readiest triumphs are to be won right here--in the valleys of the Connecticut, the Hudson, the Susquehanna, and the Potomac.