IMPROVEMENT OF SALT-MAKSHES. 255 



rangement consists of a flume of plank, built in the em- 

 bankment, as shown at fig. 136, in which three or four 

 or more narrow planks are made to fit in grooves. When 

 the water has become clear, and is ready to be withdrawn, 

 the top plank is raised at one end, or is removed alto- 

 gether, and the water allowed to escape. When the water 

 has reached the top of the second plank, that is removed, 

 and so on until the ground is cleared. 



As soon as a deposit has been made, sufficient to bear 

 a growth of grass, the seed may be sown and the operation 

 suspended. It may be repeated again when the herbage 

 has taken root, in which case the management will be 

 precisely the same as that of a water meadow, described 

 in Chapter XII, and the same rules that are there given 

 will be proper for its treatment. 



The reclamation of Salt Marshes is a work of draining, 

 primarily ; and would be out of place here, except that 

 the following work, the freshening or desalation of the 

 soil, which is a process of irrigation, is so closely con- 

 nected with it that the one becomes a part of the other, 

 and can only be carried on in conjunction with it. The 

 importance of the reclamation of the millions of acres of 

 salt marshes along the coasts, is so highly considered by 

 thoughtful persons, that at a recent meeting of a scienti- 

 fic society at Boston, this was stated to be one of the 

 chief means of the recovery of the agriculture of Massa- 

 chusetts to its former vigor and profitable success. 



The drainage of salt marshes consists in embanking 

 them from the tidal flow, in draining the waters from the 

 marsh into ditches, from which the escape is by means 

 of sluices with gates which permit the outflowing water 

 to pass, but which close themselves against a flow from 

 without. A gate of this character is shown at figure 59. 

 As soon as the salt water has been diverted from the land, 

 the work is but begun ; for the soil, saturated with salt, 

 produces no herbage but coarse sedges, reeds, or other 



