210 



THE DEPTHS OF THE SEA. 



soft mud. I mention these soundings thus parti- 

 cularly because they are the first authentic instances 

 of any quantity of the bottom having been brought 

 up from such depths. The clamms were used with 

 strong whale line made of the best hemp, 2 \ inches 

 in circumference. The weight recommended by Sir 

 John Ross for the sounding in the North 

 Sea is fifty pounds. 



One of the earliest and certainly not the 

 worst of these miniature dredges is a simple 

 modification of the common deep-sea lead, 

 the 'cup-lead' (Fig. 37). A rod of iron 

 passes through the lead, and ends a few 

 inches beneath it in a conical iron cup. 

 A thick bend-leather washer slides freely 

 on the rod between the end of the lead and 

 the cup. The theory of this instrument is, 

 that as the lead runs down, the current of 

 water keeps up the washer, leaving the 

 mouth of the cup free. On reaching the 

 ground, the weight of the lead drives the 

 cup into the mud or sand, and the lead falls 

 to one side. When the lead is hauled up, 

 a sample of the bottom goes into the cup, 

 and is retained there by the washer, which 

 is pressed down upon the top of the cup 

 during its upward journey by the reversal 

 of the current. The 'cup-lead' is very 

 useful for moderate depths. Twice out of three 

 times it brings up a sample, but the cup is too open 

 and the means of closing it are too crude, and the 

 third time everything is washed out and the cup 

 comes up perfectly clean. Deep soundings take too 



I : 37.— Thi 

 • Cup lead." 



