37o THE POPULAR SCIENCE MONTHLY. 



hoods have artesian water. The whole valley is hot as a furnace, 

 and the steaming canals probably make it seem hotter than it 

 would, and may breed malaria as well as frogs and mosquitoes. 



The Secretary of the Interior is reported to have sent an agent 

 to Europe to study the subject of irrigation. We have a corps 

 of engineers and a senatorial committee studying it in America. 

 On the whole, it looks as if we ought to find out something about 

 it. I have made a special study of it, and find it quite interest- 

 ing. There is, perhaps, no more striking application of science to 

 agriculture. You must know how to compute the mass of water 

 that will flow through a ditch of a given size with a given fall. 

 You must also know how much water will irrigate your particu- 

 lar piece of land. This will depend on its character as well as its 

 size, and also on its annual rainfall. 



It is astonishing how much the commonest Calif ornians know 

 about rainfall records. Rain-gauges are kept everywhere. The 

 morning after a shower the farmers, instead of merely informing 

 one another that it has rained, fall to talking of the quantity 

 and there is a good deal of sense in that. " My gauge showed 

 fifty-seven hundredths of an inch," says Farmer Jones. "That 

 makes 11*24 inches we have had this season," says Farmer Brown ; 

 " last season up to this time we had 13"42." And then they dis- 

 course of the precipitation yet needed to produce a crop without 

 irrigation, or with partial irrigation, and the amount of irrigat- 

 ing water that will be required. The morning paper will give 

 the rainfall in hundredths of an inch for a number of points 

 throughout the coast country. 



The size and strength of dams, head-gates, levees, etc., are mat- 

 ters requiring mathematical calculation of a delicate kind. Johns- 

 town tells with terrible earnestness how important it is that these 

 calculations should be to the last degree accurate. A careful sur- 

 vey of the route of each important ditch is also necessary. In 

 fact, a number of sciences are involved in irrigating, but " prac- 

 tice makes perfect." Little by little the Western farmers are 

 learning to depend more on cultivation and less on irrigation. 

 They find it better in many ways ; they now irrigate a greater 

 area with the same amount of water. This hastens the day when 

 the much-talked-of storage will pay. 



What ought the Government to do in the premises ? Tax the 

 East to dam the West ? I should say not, unless the expense were 

 recouped. Perhaps it might construct the works and increase its 

 prices on the land benefited. It gives lands to railroads in alter- 

 nate sections, and then gets even by doubling the price of its own 

 lands. What sort of a plan would it be for Uncle Sam to follow 

 the example of the land-operators above mentioned irrigate his 

 land and sell it off at auction ? He might sell it on sealed bids. 



