GEOLOGY OF AGRICULTURE. 69 



show that more depends upon the farmer on a farm, 

 than upon the rocks under it. 



94. "We all know, that where a torrent from the 

 hills flows into a pond, it deposits its gravel at, or a 

 little above, its mouth, while it carries its fine sand 

 into the pond, and its still finer sediment some distance 

 further. If that pond should be drained and cultiva- 

 ted, it is quite possible that the land above the former 

 mouth of the stream might be found too gravelly ; 

 that, just below, too sandy ; and that, at some distance, 

 too clayey. Various causes, on a larger scale, some 

 of them probably similar to this, have left rather too 

 much coarse matter in some places, too much silica in 

 others, and in some not enough. Energy and perse- 

 vering labor, scientifically directed, will overcome the 

 difiiculties ; and nearly all lands will yet be made 

 good. Science has shown that our poorest pine plains 

 have in them the essential elements of grain crops for 

 an* indefinitely long time to come ; that they only 

 need to be brought into action, and that this can be 

 done. We all know that our swamps, now almost 

 useless — better sunk than floating, if that would not 

 make a worse hole than now exists — are sources of 

 endless fertility. We will not blame our fathers, that 

 they did not bring them into cultivation ; they could 

 not do everything; but let us do, in this matter, what 

 they (perhaps wisely, in their jcircumstances) have left 

 undone. , 



95. Nearly all lands are yet to be made productive. 

 We must»take first those that will pay best. Others 



