336 TRANSACTIONS OF THE 



ground, that drainage has remunerated us well for the outlay. You will 

 find that the if the annual increase of trees on undrained land is five per 

 cent., the increase on drained land will be ten per cent., and on land 

 drained and irrigated, twelve per cent. In perfect drainage, twenty-four 

 hours' rain should percolate through, and leave the land in twenty-two 

 hours from the time the drains began to perform their duty. This can only 

 be effected by forming a large subterranean area of porosity. The continu- 

 ation of water in the soil for a longer period than capillary retention could 

 allow it to remain, is mechanically and chemically hurtful, from the fact 

 that it causes density and sediment. A narrow and deep drain will afford 

 much porocity at the least cost. 



The material with which the drains are filled should be durable, without 

 possessing much capillary attraction. If circumstances compelled me to 

 use pipes instead of stones for a drain, I would place hard, round stones 

 under them, to prevent choking by superincumbent soil, and to resist side 

 pressure. Stones scarcely have any mechanical afiinity for water, and do 

 not offer obstructions to its passage. Every eighty yards in length, a drain 

 should open into one somewhat larger, or percolation will be delayed. I 

 would recommend that no perishable material should be placed in a drain. 

 I have used bushes, straw, stalks, hay, &c., but find reverted bogs the best, 

 and nest, sods, with the grass side down. In every ten acres there should 

 be one main open ditch for the closed drains to empty into. The absence 

 of such an artery renders many drains perfectly useless. While water en- 

 ters drains at the sides, its most rapid and constant entrance is at the bot- 

 tom, where the main pressure is. The deeper the drain, the greater will 

 be the weight of the column of water, and the more quick the filtration, 

 which at two feet will be double that of one ; at six feet, six times as great, 

 and so on, in proportion to the superincumbent weight of water. 



I once cut drains through a piece of wet land, four feet deep, and although 

 the ground was exceedingly wet to within ten inches of the surface, no 

 water flowed through them ; I then added another foot.^ which permitted 

 gravity to overcome the suspensive power, and they rapidly filled with wa- 

 ter to the depth of eleven inches, and continued permanently to perform 

 their duty ; showing plainly that the deeper the drain, the higher the water 

 will be compelled to ascend, and the more time it will take to reach the 

 surface, the active delaying forces being space, gravity, and friction, caus- 

 ing slow evaporation, and consequently a dry and warm soil. On undrained 

 land, water is the greatest enemy the agriculturist has to contend with, 

 but on a well drained soil it is his very best friend ; and he can never have 

 too much of it, as it is our richest manure, and percolates the soil' loaded 

 with heat, carbonic acid gag, ammonia, and other chemical combinations. 

 You all are aware that in summer, if you place the thermometer one inch 

 below the surface of the ground, it will immediately indicate one hundred 

 and thirty-seven degrees, and of four feet six inches, only forty-four de- 

 grees. After a heavy rain of twenty-four hours, try the same experiment, and 

 you will probably find, as I did, that the heat on the surface was one hun- 



