AMERICAN INSTITUTE. 433 



4. Ey removing obstructions to the free working of the land, 

 arising from the surface being at certain times from excess of 

 moisture too soft to be worked upon, and liable to be poached by 

 cattle. 



5. By preventing injuries to cattle or other stock, correspond- 

 ing to the effects produced on human beings by marsh miasma, 

 chills and colds, inducing a general low state of health, and in 

 extreme cases the rot. 



6. Ey diminishing the damp at the foundations of cattle sheds 

 and farm buildings, which causes their decay and dilaj^idation as 

 well as discomfort and disease to the cattle. All these evils lower 

 the productiveness and diminish the money value of lands, as 

 well as the comfort of the farmer. 



When there happens to be two outfalls into the same main 

 drain, from the same description of land, the one from surface 

 drained, and the other from under or thorough drained, the water 

 from the thorough drained will run perfectly clear and pellucid, 

 while that from the surface di-ained will be thick and muddy 

 from the solid particles contained in it. Draining is generally 

 regarded as the means of freeing the land from springs, which are 

 the cause of underwater. 



Springs may be explained on the principle of Artesian wells. 

 Rain falling on high lands runs over the. surface to all lower 

 levels. If in its progress it passes over clay or impervious rock, 

 it of course cannot sink. If it encounters sand or gravel it sinks 

 and flows until it reaches an impervious basin from whence it 

 rises to the surface by pressure of the water entering at higher 

 levels, and causes outbursts in great numbers in all undulating 

 and hilly countries, and on clay lands usually from marshes. 



When you find the main spring, by boring or otherwise, you 

 must ascertain its subterraneous bearings by means of leveling, 

 you can then cut it off effectually in a cheap manner; if you do 

 not do so, all your labor will be lost. I have sometimes cut 

 within three feet beyond a spring, misled it, and found my drain 

 of no service. After great cost and numerous failures have 

 struck upon the vein, bored a hole to the spring, and thus been 

 successful. In other cases I have drained five feet Avithout suc- 

 cess, and have then gone down two feet further into a gravel bed 

 and found water enough to turn a mill, and many of my drains 

 are seven feet deep, on land that no casual observer would sup- 

 pose required draining at all. 



Drains should invariably be dug parallel to each other, and run 

 directly down the steepest descent, because the water will have 



