FISH CONTROL 193 



THE SUB-AQUEOUS SAW 



Should the aquatic growths be extensive, it generally will pay 

 to remove them. This may be accomplished by means of 

 scythes and sickles from a boat, but the best method, in most 

 cases, is by use of a sub-aqueous saw. This saw, a pliable, 

 toothed strip of steel, 100 or more feet in length, will cut many 

 kinds of aquatic plants successfully, providing only that the water 

 is not studded with brush or stumps. Probably the best saw of 

 this kind is the Ziemsen saw. a patented article. 



A somewhat similar, but not so effective, a saw, may be made 

 very cheaply from "licker-in" wire, which is used in a combing 

 process in cotton mills and which may be purchased from mill 

 supply houses. This wire resembles a single-edge saw. By ty- 

 ing two wires together firmly, back to back, at intervals of 8 to 10 

 inches, with the cutting edges in opposite directions, a double- 

 edged saw may be made, capable of cutting in either direction. 

 Twisting seems to improve the cutting action. In order to make 

 the saw follow the contour of the bottom, weights should be 

 attached to it at 4 or 5-foot intervals. Ropes should be tied to 

 each end to take hold of in sawing. 



To use the saw, it should be dropped to the bottom, the ropes 

 stretching to either shore. If the saw is not more than 100 feet 

 long or so, one man at each end can handle it; if it be several 

 hundred feet long, however, two men at each end probably will 

 be required. If there are many bushes or stumps, there should 

 be a man ready in a boat to disengage the saw T or lift it over the 

 obstacle, whenever necessary. Should the span exceed the 

 length of the saw, one end will have to be worked from a boat. 

 This is tedious and difficult. 



USING THE SAW 



The sub-aqueous saw is worked on the principle of a cross-cut 

 saw, the men pulling alternately on each end. The work is 

 very fatiguing, and the men will have to rest frequently. Where - 

 there is a current, it is best to begin at the downstream end and 

 work upward against the current; this permits the cut-off 

 growths, as they rise, to float clown stream out of the way, to 

 be collected and hauled ashore later. If there is no current, it 

 is preferable to cut in the direction of the wind, if there is any. 



One annoying factor in connection with the use of the sub- 

 aqueous saw is the frequent breaks, especially in the case of the 



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