382 BOARD OF AGRICULTURE. [Pub. Doc. 



encountered in the work a chance to run off without pump- 

 ing. It is usually better also to lay the tile in the same 

 older, especially if the quantity of water is large and the 

 trenches liable to cave. Throw the surface soil upon one 

 side of the trench and the undersoil upon the other; and in 

 refilling restore the different materials to their proper 

 places, observing that the tilling immediately around the 

 tile should be of the coarser materials best adapted to 

 exclude silt. 



Make the trench no wider than is necessary for the con- 

 venience of the workmen, say from twenty to twenty-four 

 inches at the top and from live inches upward at the bottom, 

 according to the size of the tile. Excavate to the proper 

 grade, and dress the bottom of the trench accurately by 

 using a levelling rod or pole having a target or conspicuous 

 mark thereon at the same distance from the bottom of the 

 rod as that at' which the batter boards are placed above the 

 grade line. Test the depth of the trench frequently as the 

 work progresses, by having one man hold the rod vertically 

 in it while another sights over the top of the two batters 

 nearest thereto, to determine whether the target or mark 

 thereon is in the same line with the batters. AVhere the 

 target stands above the line of the batters, the trench must be 

 deepened ; while if it stands below the line the trench is too 

 deep, and must be refilled with material firmly packed until 

 the target is in the same grade with the batters, with the 

 rod standing on the bottom of the trench. Constant care 

 and watchfulness should be exercised to avoid digging below 

 the proper grade, as a natural bed that has not been dis- 

 turbed furnishes a better and more secure foundation upon 

 which to lay the tile 



Of the various forms of tile in the market, that known as 

 "Ohio" or " Ohio land" tile is among the best. The bore 

 is circular in cross-section, while the outside is polygonal 

 (either hexagonal or octagonal). They have the advantage, 

 therefore, of six or more sides or beds upon which they can 

 be laid. All drain tile, however carefully made, are liable 

 to be warped or curved in drying and burning, whereby 

 with but one bed upon which to lay them many of the joints 



