THE DRAINAGE OF FARM SOILS 213 



small area is to be drained, and the land is not 

 very flat satisfactory work may be done by a care- 

 ful man without a level. 



A Home-made Level. There are many simple 

 devices for establishing a grade. King recom- 

 mends a "water level," which is easily made at 

 home. It is made of a piece of f-inch gas 

 pipe, four feet long, with a T exactly in the 

 center and ah elbow at each end. A piece of 

 pipe about six feet long is inserted in the T 

 and sharpened at the lower end, making the 

 standard which is thrust into the ground. A 

 short piece of glass tube, J-inch in diameter, is 

 cemented into each L and the top of each tube is 

 fitted with a cork. Each tube should project 

 exactly the same distance above the L. Fill the 

 gas pipe with water, coloured with ink or bluing, 

 until it just shows in both of the glass tubes when 

 the pipe is exactly horizontal. When using this 

 improvised level, stick the standard firmly into 

 the ground, remove the corks and adjust it until the 

 water shows that the horizontal pipe is perfectly 

 level. Then step off four or five feet and sight 

 across the top of the two tubes. If used carefully, 

 this instrument does quite accurate work for short 

 distances. 



There are many ways of using this and other 

 kinds of levels. The simplest way, for drainage 

 work that is not complicated, is to first set the level 

 some 50 or more feet from the outlet. Sight back 

 to the outlet, set the measuring rod on the ground 

 and note the height at which the level sight strikes 

 the rod. It may be 4 feet 6 inches, for example. 

 With the instrument in the same position find 

 the height at which the sight strikes a rod , set about 

 50 feet in the opposite direction, along the line which 



