be room enough for a good-sized tub in which to dump the result of 

 the dredging. 



" Let us now suppose that we are in a boat ready to dredge. We 

 first put the dredge over the stern, mouth downward, and let it gradually 

 sink, playing out the rope very carefully to avoid knots and twists. I 

 neglected to say that before the dredge is placed in the water, a lead 

 weight of about ten pounds should be fastened to the rope ten or fifteen 

 feet from the mouth of the dredge. This is to keep the mouth in con- 

 tact with the bottom of the sea, when it is being pulled along. When 

 the dredge is felt to touch the bottom, the dredger should play out 

 enough rope to equal twice the depth. The dredge line is now fastened 

 to a cleat in the stern, and the line allowed to pass over the notch cut in 

 the stern for the sculling oar. This is necessary in order that the rowers 

 may keep in straight line. 



" After the dredge touches the bottom, the rowers may pull the boat 

 for quite a distance before the dredge is ready to be pulled up. By the 



Sketch showing method of dredging from a rowboat. D, the dredge; 

 w, the weight placed ten feet from the mouth of the dredge. (Dall.) 



peculiar vibrations of the line, one soon learns to judge correctly when 

 the dredge is on the bottom, when it is catching well, when it is 

 caught by some obstruction, or when it is not catching at all. When 

 the dredge is thought to be full it may be pulled up and its contents 

 dumped into the tub. It is sometimes well to examine the material near 

 the mouth of the dredge for fear there may be some very delicate speci- 

 mens which may be broken. The material in the tub may afterwards 

 be picked over and the specimens properly cleaned. Notes should 

 always be made regarding each haul of the dredge, giving all possible 



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