THE OYSTER INDUSTRY OF NEW JERSEY. 477 



heavy freshets of water during the warm weather in the latter part of 

 July. 



An aquatic moicing-mncMne. — Eelgrass grows abundantly in some 

 parts of the ISTavesink Eiver, and, as in other localities where it is 

 found, acquires in due time full possession of the areas where it grows, 

 rendering them useless for oyster-culture. In combating this enemy 

 of the oyster-planting industry, Mr. Charles T. Allen, of the firm of 

 Snyder «& Allen, Oceanic, N. J., has achieved a degree of success here- 

 tofore unequaled. After expending much fruitless labor in efforts to 

 mow the eelgrass with a scythe, a method which proved impracticable 

 because the water was sometimes too deep and also on account of the 

 diflSculty of cutting grass growing under water, he invented in 1885, 

 and has since used, a device which may be termed an aquatic mowing- 

 machine. The machine is rigged on a sqnare-ended scow 20 feet long 

 by 8 feet wide. On the forward end of the scow is suspended, by a 

 framework, a double set of knives, each set being similar to those of 

 mowing-machines used by agriculturists. The object in having double 

 knives is to enable the machine to cut when moving backward as 

 well as when moving forward, thus avoiding the necessity of having 

 to turn the scow around when the end of the swath is reached. The 

 knife bar is 12 feet long and consequently cuts a swath 12 feet wide. 

 The power for propelling the machine is supplied by a six-horse power, 

 high pressure, condensing engine, which is located in the middle of the 

 scow. A line 1,000 feet in length is passed with three turns around a 

 winch-head, and drawn taut by an anchor at each end, placed a short 

 distance beyond the extreme boundaries of the area to be mowed. It 

 is held in position by a fair-leader or chock, having a shive on each 

 side similar to the shive of an ordinary tackle-block. The shives 

 facilitate the passage of the line through the leader by lessening the 

 friction, and correspondingly decrease the wear upon it. The leader 

 or chock is placed on the forward end of the scow, and not only serves 

 to hold the line in position but also keeps the scow straight in its 

 course. 



When the engine is started the winch-head revolves, and the pres- 

 sure of the line, encircling it in three turns tightly drawn, forces the 

 scow through the water. The rate of speed at which it can be operated 

 is 1,000 linear feet in 5 minutes, thus enabling it to mow an area of 

 2,000 square feet or more per minute, or 1 acre in from 20 to 22 min- 

 utes, making allowance for time spent in moving anchors or otherwise 

 adjusting the machinery. 



When fitted for work, with coal and water, and manned with 3 men, 

 including an engineer, which is the number requisite to operate the 

 machinery and attend to shifting the anchors, the draft of the scow is 

 ab(mt 8 inches of water. When the anchors have once been adjusted 

 several swaths can be mowed before they require to be shifted over 

 toward the uncut grass, as the line can not easily be drawn so taut, 

 nor does it need to be. as not to allow the scow to be moved 



