ECONOMICAL GEOLOGY. 95 



Im-provement of the Beaches. — In the early part of the re- 

 port, the rapid wearing awaj of the beaches was alluded to. 

 This wear has been much increased by cutting off the 

 timber, so as to leave the sand loose and exposed to the 

 full force of the wind. The value of these beaches is 

 not very great; but it might be much increased by 

 favoring the growth of timber on them; and they are 



the area of the sluice, so as to prevent any considerable resistance to the flow of water), 

 an embankment is thrown up all around the intended compartment. The dimensions 

 of the embankment are commonly two or three feet wide at the top, with a slope of fifteen 

 to eighteen inches horizontal to one foot perpendicular; the altitude varying according 

 to the level of the surface. Of course the actual levels of the ground and of the river- 

 water must be ascertained, in order to determine the height of the embankments ; but 

 this may decrease as they recede inland from the river, because the water does not 

 rise so high in the compartment as in the stream, owing to the ebb-tide commencing 

 before high-water mark is felt in the warping ground. When the water is to be admitted, 

 the doors of the sluice — which point outward, so as when self-acting to exclude the tide^ 

 are held open by rods and staples attached for the purpose, the thick-water flowing ra- 

 pidly in carries the mud in suspension until arived at the point where it begins to expand 

 in a quieter current, and then lets it fall slowly upon the surface it inundates. The warp- 

 ing drain is prolonged to the farther side of the compartment, say along one side, and the 

 deposition there begun ; the water passing very slowly back over the ground, and escaping 

 again into the drain at the turn of the tide by a tunnel laid for the purpose on the near 

 side of the compartment. When the farther side has received a sufficient coating, the 

 water is admitted through an aperture cut in the bank at a less advanced position, and 

 so on, until the water gradually shuts itself out. .... Great care and judgment are 

 required in guiding the currents of water from the inlets, so as to insure an equal distribu- 

 tion of the warp, both as to quality and to the final uniform level of the surface. . .» . 

 The water having flowed over the ground again into the drain — mimis much of its earthy 

 matter — returns to the river, scouring out in its passage any deposit that may be accumu- 

 lated in the drain. . . . The water is not shut up in the compartment; the deposition 

 commences directly it has got free from its restraint in the drain, and it is run off as 

 quickly as the tide wUl allow, in order to make room for another flowing, 



"The expense is a very variable item, depending upon various conditions. With the 

 cost of large drains and other works included, it would probably be from £12 to £20 per 

 acre ; while on lands adjacent to the public warping drains, it would be much less than 

 half that sum. The improvement, however, is very valuable, as it converts most worth- 

 less moors into firm, dry, und prolific land, worth £60 to £100 per acre, and commanding 

 a rental of 50». to 60s., or even much more."—" Oyc. of Agr ,• Art. Warping." 



