124 ESSAY ON DEEP TILLING. 



till freezing asain occurs. At this period, the undrained land, 

 having the most water to freeze, becomes the warmest, say in 

 December, when of no value to vegetation, but rather an injury. 

 For once, forsooth, the undrained land is warmer than the drained ! 

 But for this excess of heat in winter, this kind of land must pay 

 dearly in early spring. How is all this ? enquires the farmer. 

 Simply because water in congealing to either ice or snow has its 

 capacity for heat lessened about one ninth, and this excess is given 

 oif to surrounding bodies ; or in other words, its latent heat is set 

 free. On the other hand, ice, or frost as it is called in the ground, 

 in melting, demands back this same heat, at the rate of from one- 

 eighth to one-ninth of 1000°, for every pound melted ; and un- 

 der the surface it does not obtain all this directly from the sun, 

 but through the soil. Therefore the more water the colder and' 

 longer cold will be the land in the spring. Now let the agricul- 

 turist go to work and make this " cold, wet, heavy land " of his, 

 the very best he has for any product, trees, vegetables, grains or 

 grasses. Expense is his next objection. To this we will allude 

 in passing. 



TRENCHING. 



This is understood to be simply inverting the ground to a given 

 depth, without change of material or place, except for the mere 

 faciUty of the operation. We generally make the trenches three 

 feet wide and from two to three feet deep, never less than two. 

 The bottom of each, after being thoroughly loosened with spade or 

 pick, should receive the small stones, brush, horn piths, or any 

 rubbish at hand, and then the sod or surface soil of the next section 

 to be shovelled over. It may be necessary to vary the depth ac- 

 cording to the condition of the sub-soil. If hard strata of sandy 

 or clayey loam are met with, they should be broken up for the free 

 transmission of water. In decidedly clay bottoms through which 

 water will not pass, we construct drains a foot below the grade of 

 the trenches, and 25 feet apart ; and if the inclination of the land 

 will admit of it, at right angles with the latter. After a trench is 

 finished, these bits of drains are sunk, corresponding with those of 

 the preceding trench. 



A man will trench about two square rods in a day, which at a 

 dollar per day amounts to eighty dollars an acre. But many labor 



