DEVICES, APPLIANCES AND CONTRIVANCES. 397 



should be leveled, so that the sewage may flow equally 

 over every portion. It should also be laid out with 

 distributing channels having a proper inclination, in 

 order to deliver the sewage readily to all parts of the 

 farm. Formerly it was considered necessary that 

 the carriers be lined with earthenware, concrete, or 

 other impervious material, to prevent the sewage sink- 

 ing into the ground during its passage along them, but 

 now the more ordinary practice is simply to make earth 

 ditches with flat slopes. As to the best size of the 

 field for irrigation, everything depends upon the quan- 

 tity of sewage to be disposed of and the chara(5ler of 

 the soil. Any ordinary crop can be grown by this 

 system. 



Artesian Well Machinery. — The success of ar- 

 tesian wells in some sedlions is phenomenal, and they 

 prove a valuable acquisition in irrigation advancement 

 where artesian basins exist not too far from the sur- 

 face. A very good well, suitable for irrigation pur- 

 poses, is to be seen in Fig. 93. 



The cost of an artesian well not over five hundred 

 feet deep ought not to exceed one dollar a foot, includ- 

 ing casing, and contradlors will do the work for this 

 sum. The cost of sinking generally increases more 

 rapidly than the depth, so that except in cases of easy 

 boring, or great supplies of water, it will not pay to 

 attempt deep wells for irrigation purposes. The tem- 

 perature increases with the depth, which is an advan- 

 tage if the water is to be immediately applied, but the 

 water is also more mineralized, which is. a disadvan- 

 tage, or not, according to the charadler of the solids 

 present. 



