Farm Drainage. 371 



size, with a Hat sok' or bottom on wliicli it rests. Some 

 have been made square, aud others round witli a colhir of 

 the same material, wlii(;h extends some one and a lialf 

 inches into each end of the tile when laid, covering the 

 joint so as to keep out dirt or silt. The laying out or engi- 

 neering is an important operation, all writers on the subject 

 putting so nnicli stress upon it as to claim the necessity of 

 employing a practical engineer ; and there may be cases in 

 which the land is so nearly level that it would be necessary 

 to use a surveyor's level in order that the proper grade may 

 be obtained at all points, an absolute necessity^ else the 

 drains will be utterly useless above all such points. 



The lirst thino- to determine is where the water will be 

 taken from the field, w^hich, in nearly all cases, will be at 

 its lowest boundary, and nnist always be where there is a 

 good fall — otherwise, the silt or nnid from the drains M'ill 

 soon clog the mouth, and it will fill back as fast as 

 mud or silt enough finds its way into the tiles, and in a 

 short time would become useless. 



Usually we run a main drain from tliis point through the 

 lowest part to the farthest boundary of the lot ; tlien lay 

 lateral drains, running into this at an acute angle between 

 the main and these laterals, never being laid in I'ight 

 angles, and on a smooth piece should be laid parallel, 

 and at intervals proportionate to their depth. Scientific 

 w^riters say twenty feet apart for three feet drains, forty 

 feet apart for four feet drains, or eighty feet for five feet 

 drains. My own custom has been forty feet apart for three 

 feet depth ; but, in most fields, inequalities of the surface 

 govern the localities of many of the drains. 



