FISHERIES OF KEY WEST. 65 



filled they are placed on a small car and rolled to the end of the 

 dredge, where they are piled up until transferred to the run boat. 



From two to four men are required to pick the clams from the 

 conveyor, which moves at a speed of about 1 foot per second. At 

 times a moment will pass when there are no clams, but suddenly a 

 dozen or more will appear in a cluster. The pickers are generally 

 kept continuously busy, and they are very skilled in picking out the 

 live clams from the masses of debris and dead shells. The fact that 

 all undesired material is automatically cast back into the water, with- 

 out the slightest physical effort, is one of the principles that made 

 this type of dredge a success. A full crew consists of a captain, engi- 

 neer, cook, rope man, four clam pickers, and one man to care for the 

 baskets as they are filled. 



The dredge moves slowly while digging, traveling 1,200 feet in 

 about one and one-half hours. This slow movement is accomplished 

 by drawing in on a 1,200-foot cable attached to an 800-pound anchor. 

 The distance traveled when the full length of the cable has been 

 drawn aboard and the dredge reaches the anchor is termed a " run." 

 With the anchor as a center each run of the dredge compares with 

 the radius of a circle. Upon the completion of a run the cable is 

 released and the dredge drifts back with the wind and the tide, and 

 because of their variation the dredge never digs over the same course 

 twice except possibly near the anchor where all the radii meet. 

 Because of the great abundance of clams it is said that the dredge 

 has been able to dig in one locality for several months at a time 

 without shifting its anchor. 



It has been claimed that large mounds of mud are left on both 

 sides of the strip of bottom that is being dug over, but from the 

 mechanism and operation of the machine this would seem very im- 

 probable, as the soil is not dumped to one side or the other but is 

 merely worked over and deposited .again more or less uniformly. 

 The teeth of the dredge dig an area about 5 inches deep and nearly 

 6 feet wide. As the teeth strike the bottom, part of the muddy soil 

 passes through the interspaces, while whatever mud adheres to the 

 teeth is partly washed away before it reaches the wooden belt con- 

 veyor. The conveyor casts the residue back into the water, breaking 

 it up still further before it reaches the bottom, and much of the mud 

 settles back evenly on the bottom from which it was taken. For 

 this reason it is not believed that clams or other animals are smoth- 

 ered bv becominsf buried beneath a heavv laver of soil and debris. 



The majority of the clams dug by the dredge are from 2| to 5 

 inches in size, measured f *om the hinge ligament to the farthest oppo- 

 site point. Very few small clams are dug, but it is possible that they 

 pass between the teeth of the dredge or are otherwise lost before 

 reaching the wooden conveyor. About 3 per cent of the clams are 

 broken by the digger, and are discarded as they would be decomposed 

 by the time they reach the canneries. 



The dredge digs from 80 to 120 five-peck baskets of clams on one 

 run, and from 350 to 450 baskets during a day. As there are now 

 (1923) two dredges in operation, this quantity of clams is utilized 

 by each of the two canneries every working day. During 1922 the 

 one dredge in operation worked about 300 days, digging continu- 

 ously throughout the year except during part of August and Sep- 

 tember, which is known as the " gale season." 



