888 THE COMPLETE GRAZIER. BOOK ix. 



,the course of a season a foot of rich soil is, on an average, added to 

 the former surface, and, in low situations, two or three or four feet, so 

 as to have a perfectly level surface. 



In order to render this process more efficacious, the water must be 

 perfectly at command, so that it may be excluded or admitted at 

 pleasure ; and the land should be below the level of high tide. Hence 

 it is necessary not only to cut a canal communicating with the river, but 

 also to have a sluice at the mouth of it, which may be opened or shut 

 as circumstances require ; while, in order that the water may be of a 

 proper depth on the surface of the ground to be warped, and also to 

 prevent adjacent lands from being overflown, strong banks are raised 

 around the fields, from three or four to six or seven feet in height, 

 according to circumstances. Thus, if the area is of considerable 

 extent, the canal which takes the water may be made several miles in 

 length. It has been tried as far as four, so as to warp the lands on 

 both sides the whole way. Lateral cuts may be made in any direction 

 for the same purpose, thus allowing the water longer time to deposit 

 its sediment, for the effect decreases in proportion to the distance of 

 the land from the river. 



The following practical instructions for conducting the process of 

 warping we give in the words of Mr. Thornton J. Herepath : 



"An excavation having been made in the river-bank, under the bed 

 of the stream, a dough is built, which directly communicates with a 

 main drain or duct. This drain is furnished with substantially-built 

 raised embankments of very solid earth, and is formed for the purpose 

 of conveying the muddy water from the river to the land intended to 

 be warped, over which it is gradually and equally distributed by numerous 

 smaller lateral drains, the said land having been previously laid as nearly 

 upon a level as circumstances will admit. In order to confine the water 

 to this particular spot, and prevent it from overflowing the adjacent 

 country, the land is surrounded and divided into compartments by 

 strong well-formed banks, winch are of the same height as those of the 

 main feeder, but neither so wide nor so solid. Then again, there is 

 an inner bank all round, which has openings in it adjacent to the 

 lowermost parts of the land, for the purpose of getting the muddy 

 water to these places as soon as possible. In this way every flood-tide 

 is conducted into every one of the compartments in succession, and as 

 it ebbs, the hydrostatic pressure of the water alone suffices to force open 

 the swinging doors of the return sluices, thus allowing itself to escape 

 into the main canal and thence into the river, after having deposited 

 nearly the whole of its mud upon the surface of the enclosed land. Of 

 course, the higher the tides are, the greater is the depth of water to 

 produce the deposit, and vice versa. Considerable skill must be 

 exercised in adjusting the size of the doughs, so as to discharge the 

 whole of the water before the rise of the next tide, as otherwise only 

 every other tide can be admitted. 



" B} r the above plan it has been found possible to w.irp land in one 

 year to the depth of two or three feet, and this is generally considered 

 to be quite deep enough, and is permanent in its action. This state- 



