eozet's plan. 496 



abandoned without involving too great a sacrifice of existing 

 interests, tlie elevation of the dikes should be much reduced, so 

 as to present no obstruction to the lateral spread of extraordinary 

 floods, and that they should be provided with sluices to admit 

 the water without violence whenever they are hkely to be over- 

 flowed. "Where dikes have not been erected, or where they have 

 been reduced in height, it is proposed to construct, at convenient 

 intervals, transverse embankments of moderate height running 

 from the banks of the river across the plains to the hiUs which 

 bound them. These measures, it is argued, wiU diminish the vio- 

 lence of inundations by permitting the waters to extend them- 

 selves over a greater surface, and by thus retarding the flow of 

 the river currents, will, at the same time, secure the deposit of 

 fertilizing slime upon all the soil covered by the flood.* 



Rozet, an eminent French engineer, has proposed a method of 

 iiminishing the ravages of inundations, which aims to combine 

 the advantages of all other systems, and at the same time to ob- 

 viate the objections to which they are all more or less liable.f 

 The plan of Rozet is recommended by its simplicity and cheap- 

 ness as well as its facility and rapidity of execution, and is looked 

 upon with favor by many persons very competent to judge in 

 such matters. It is, however, by no means capable of universal 

 appHcation, though it would often doubtless prove highly useful 

 in connection with the measures now employed in Southeastern 

 France. He proposes to commence with the amphitheatres in 

 which mountain torrents so often rise, by covering their slopes 

 and fining their beds with loose blocks of rock, and by construct- 

 ing at their outlets, and at other narrow points in the channels of 

 the torrents, permeable barriers of the same material promiscu- 

 ously heaped up, much according to the method employed by 

 the ancient E.(3mans in their northern provinces for a similar 

 purpose. By this means, he supposes, the rapidity of the current 

 would be checked, and the quantity of transported pebbles and 



* The system described in the text is substantially the Egyptian method, the 

 ancient Nile dikes having been constructed rather to retain than to exclude 

 the water. 



t Moyens de forcer les Torrents de rendre une pa/rtie du sol qu'iU ravagent, et 

 cCempicfier lea grandes Inondations. 



