can be exercised: it originated in Yorkshire , and is carried on toa great extent, especial'} 7 along the banks of the Ouze, betweenYork and the mouth of the Humber. When in that district, wehad the opportunity of examining and ascertaining the differentbranches of that valuable operation, all of which are important,their effect being the same on a poor soil, as upon one of thegreatest natural value.
The river Ouze, is constantly stored with mud, and all sortsof alluvial matter. Being stirred, and kept in motion by thetide, that alluvial matter is, by the process of warping, convey-ed over the adjoining lands, which are flat and easily flooded. ”
The manner in which this is done, is fully described in theWest York Survey, drawn up by the same gentleman, and myfriend Mr. Rennie of Phantassie. It is shortly this. “ The landto be warped, must first be banked against the river; these banksare formed of earth , taken on the spot from the land. They arebroader and higher, according to the impetuosity of the river,and the weight of the water at spring tides. In these banks,there are fewer or more openings to let in and out the water, ac-cording to the size of the field to be warped. In general theyhave only two sluices, one called the flood-gate, to admit, theother called the dough, to let off, the water gently. These areenough for 10 or 15 acres. When the spring tide begins to ebb,the flood-gate is opened to admit the water, the dough beingformerly shut by the weight of water brought up the river by theflow of the spring tide. As it ebbs, the pressure of the waterbeing taken ofF from without, the dough opens and lets out thewater slowly, which had been admitted by the flood-gate. Thedoughs are so constructed, as to let the water run off betweent he ebb of one tide, and the flow of the next. To this point, par-ticular attention is paid: the flood-gates are placed so high, asonly to let in the spring tides when opened. They are above thelevel of die common tides. ”
Secondly, The season fittest for warping, is pointed out by MrBrown, in p. 290 of his excellent treatise. “ June, July, andAugust, ” he says, “ are considered to be the best months forwarping, on account of their being generally the driest months.Land may be warped, however, in any season, providing theweather be dry, and the fresh water in the river very low.When the season is wet, and the river full of fresh water, thisoperation cannot be advantageously executed. The fresh water,in this case, mixing with the tide, makes it not half so muddyand thick, and consequently incapable of depositing the samequantity of sediment. Warping in spring, is attended with no-peculiar advantage, more than in summer, as there can be nocrop that year. The sediment must lie to 'soak and dry, beforethe ground can be cultivated, with the slightest prospect of adj-vantage.”