92 TRANSACTIONS OF THE ILLINOIS 



tilizing substances, and the surplus be discharged through the sewerage of our fields, into 

 the brooks and rivers. About twenty inches in depth of water is annually evaporated. 

 This amount is materially reduced by drainage, thus saving heat in the soil iu the sea- 

 sons of excessive rain, which are the cool seasons of the year. 



Again, drainage and deep working will largely prevent surface washing on moist 

 land, the- desirableness of which on all rolling laud, and especially among the hills of 

 Egypt, it is not necessary for me to enlarge upon. A field well worked to the depth 

 of 18 to 24 inches and kept in a porous condition as it will be, by the very fact of 

 drainage, will be able always to absorb and hold all the water falling in a single day, in 

 all but our severest 6torms, it being very rare that as much as two inches depth of 

 water falls in twenty-four hours ; while each two-inch drain pipe, laid at an inclination 

 of one foot in twenty, is capable of discharging 50,000 gallons in 24 hours, which is 

 equal to a depth of nearly two inches over one acre. 



So it is evident that with the absorbing capacity of trenched soil, and the discharg- 

 ing capacity of tile drains laid even two rods apart, there is no occasion for surface 

 drainage, or the washing which is now so rapidly robbing our soil of its richest 

 elements of fertility. 



There is another matter in which drainage will be of the greatest value to us, in pre- 

 venting the heaving of the soil, and the freezing out of plants. The average yield of 

 the wheat crop, now so small in all Egypt, would be largely increased and possibly 

 doubled from this cause alone, saying nothing of the results of a deepened soil. The 

 damage to the strawberry crop is often sufficient in one winter, to many times pay the 

 whole expense of tile-drainage. How much our orchards suffer in this climate from 

 freezing the roots in our wet winters, it is difficult to know ; but we may be sure that 

 they gain nothing by it. 



We should not forget in passing, another beneficent agency of nature in sustaining 

 vegetation — the supply of moisture during the dry season, in the form of vapor 

 and dew. It has been estimated that the annual dew deposit, is equal to five inches in 

 depth of water, or about one-fourth of our rain-fall, during the six summer months. 

 And we are surrounded with an atmosphere of vapor which is carried by the air into 

 all soils and substances which are permeable to it. Now a well drained and deeply 

 worked soil is in the best possible condition for the absorption of vapor, while an un- 

 stirred, baked soil will receive very little of it. 



The length of season given for working an under-drained soil, is another great advan- 

 tage to the cultivator With drainage, all the labors of the farm may go on in twenty- 

 four hours; after the heaviest rain ; while the undrained field will lie cold, wet and sod- 

 den for many days, and all vegetation will grow sickly. 



Time does not permit me to enumerate, even, all the advantages of the system under 

 consideration ; I will close with a few suggestions. 



I have used the terms subsoiling and trenching interchangeably, in their relation to 

 drainage ; but with relation to special crops, there should be made a distinction : 

 Sub-soiling is possibly the best treatment for the strawberry, and all those crops whose 

 roots do not penetrate the soil deeply. While I incline to the opinion that trenching 

 will be found more valuable for the orchard and vineyard, thus inviting the roots down- 

 ward farther into richer, inverted soil, and so into conditions of greater equilibrium of 

 temperature and moisture. A thorough mixture of the surface with the subsoil might 

 be the better for all crops. 



