APPABATUS AND APPLIANCES USED . 
55 
Fi& 10. 
net to catch and retain all that might come in its 
way ; at the bottom of this bag a number of hempen 
swabs were generally secured so as to sweep along 
and bring up small animal life, 
coral, sponges, &c. These dredges 
after a time were set aside and re- 
placed by the ordinary beam trawl 
used in shallow water around our 
own coast. 
The operation of dredging or 
trawling, like that of sounding, is 
carried on from the mainyard, the 
dredge rope being rove through an 
iron block which is attached to the 
accumulator in the same manner as 
described for sounding. 
For this operation it is neces- 
sary to use a muoh larger accu- 
mulator (Fig. 10), consisting of as 
many as seventy or eighty india- 
rubber bands, 3 feet in length, 
capable of stretching to nearly 20 
feet when a force of 2-J tons is 
exerted (that is, equal to the 
breaking strain of the 2^-inch 
rope). 
The accumulator is secured to 
the masthead by means of a long pendant, and hauled 
out, or eased in, by a tackle at the end of the yard, 
