290 On Warping Land. 



annum ; or in other words, of transmuting copper into gold. 

 The efforts made in Egypt to obtain, and to secure the fer- 

 tility of its soil, in circumstances not very dissimilar, are well 

 known; and shall nothing be done by the British. Govern- 

 ment, to promote an imitation of the husbandry of the Nile, 

 on the banks of the Humber, and of other rivers where it may 

 be found practicable? Why not give some species of public 

 encouragement to so great a national object ( 47 ) ? more es- 

 pecially as the valuable substance in question, (silt or warp), 

 is not confined to the Humber, but is to be met with, in great 

 perfection and abundance, in many of our other rivers and 

 arms of the sea. 



8. Of River Warping in Italy. From some late accounts 

 which have been published, of the agriculture and statistics 

 of Italy, it appears, that a species of warping has been long 

 known in Tuscany. It is there called colmata. The rivers 

 in that country carry down with them vast quantities of 

 mud and sand, by which their discharge into the sea is im- 

 peded, and great marshes are formed, not only at the mouths 

 of these rivers, but in their courses, when they are passing 

 from one level to another. Torricelli, it is said, was the 

 first who taught his countrymen to inclose the marsh with 

 a dike or embankment ; to admit, into this inclosure, the 

 water of the rivers ; to force this water, by means of sluices, 

 to remain stagnant as in a lake, so as to deposit its mud ; 

 and by the sediment so produced, to raise the level of the 

 bottom. At one time, three or four inches of earth have been 

 often deposited ; the operation has been several times re- 

 peated in the course of a year ; and the level so much raised, 

 that the ground is no longer liable to be overflowed by the 

 river. The soil thus acquired, is of the highest fertility ; and 

 an instance is mentioned, of a piece of ground thus treated, 

 which had yielded 25 measures of wheat from one ( 4?I ). 

 Necessity was the parent of this operation in Italy ; whereas, 

 on the banks of the Humber, it seems to have originated 

 from accident, and has been carried on, by a zeal for im- 

 provement, and the prospect of gain. 



SECT. XI. On Embankments. 



THE nature and advantages of embanking are twofold ; 

 1. To protect land, already under profitable production, 

 from the encroachment of the sea, of fresh-water lakes, or 

 of rivers, which often inundate the low grounds in their 



