The gravel is excavated as in the ordinary form of endless-chain bucket dredge and dumped on to the deck of the dredge.
A committee, chiefly promoted by the Wurttemberg government and the Stuttgart chamber of commerce, reported in 1901 that it was both desirable and practicable to dredge the river and to canalize it, from Esslingen down to Mannheim, and that the cost would probably be between 2 and 22 millions sterling.
This latter portion of the river's course is tortuous, but in spite of this, and although the depth varies from only 7 to 20 ft., and in places at low water does not exceed 4 ft., it is nevertheless navigated by vessels up to 180 tons burden and proposals have been made to embank and dredge it so as to increase this depth to 8 ft.
The dredge often brings up large numbers of nodules formed upon sharks' teeth, the ear-bones of whales or turtles or small fragments of pumice or other volcanic ejecta, and all more or less incrusted with manganese oxide until the nodules vary in size from that of a potato to that of a man's head.
In the estuaries of Essex there are many private or semi-private oyster fisheries, where the method of culture is to dredge up the oysters in autumn and place them in pits, where they are sorted out, and the suitable ones are selected for the market.
Larger quantities of deposit may be conveniently collected by means of the dredge, which can be worked in any depth and brings up large stones, concretionary nodules or fossils, of the existence of which a sounding-tube could give no indication.
Of Biloxi) to Ship Island, which has one of the best harbours on the entire Gulf Coast, the Gulf & Ship Island Railroad Company, with the co-operation of the United States Government, in 1901 began to dredge a channel 300 ft.