HYDRAULIC DREDGES FOR CHANNELS 131 



small jobs at different points, and in various kinds of material, 

 some of which has been of a very difficult nature. The capacity 

 of 500 cu.yds. per hour has frequently been obtained, and, under 

 favorable conditions, the output, for short periods of time, has 

 approached 1000 cu.yds., but the average, owing to the reasons 

 already stated, has been much less than this. 



To convey the dredged material ashore lengths of sheet steel 

 pipe are used laid on the ground and blocked up where necessary. 

 These pipes are simply slipped into one another like stovepipes, and 

 no special arrangements for keeping them tight. The gravel and clay 

 in the interior soon block up any small openings, and absolute 

 tightness is not required. The material distributes itself over a 

 large area of ground. Thus for land reclamation the value of this 

 type of dredge is evident. The manner of working the dredge and 

 disposing of the material must of course be determined by the local 

 conditions, and while the hydraulic type of dredge has its limitations, 

 its sphere of usefulness, as exemplified in the "King Edward, "is 

 considerably widened. 





