46 N. J. Mosquito Extermination Association 



weight of the machine should be most seriously considered, for 

 the load per square inch of bearing surface should be small. 

 Tractors at present on the market vary from four to seven pounds 

 per square inch. A few examples of some of the meadows en- 

 countered will explain why the load should be light. Large 

 areas of marsh land are frequently found so thickly scattered 

 with salt holes and soft places that every ditch must cross many 

 of them. Running the ditches around them and tapping with 

 spurs is out of the question on account of the number. The 

 machine of the future, therefore, however light it may be built, 

 must be so equipped that the power plant can be detached from 

 the ditching plow, and pick its way around and through these salt 

 holes and then pull the plow across to solid meadow. 



The caterpillar tread of the tractor must be provided with 

 projections to grip the meadow surface to prevent slipping and 

 digging itself in when pulling the plow. 



The weight of the tractor again becomes a factor in moving 

 across creeks which are wide enough to necessitate bridging. 

 If the weight is too great, the amount of planking necessary for 

 bridging will be too cumbersome to be carried. Also, the moving 

 from area to area across thoroughfares and bays by means of a 

 scow makes lightness imperative. On one contract of a million 

 feet our records show that four machines made a total of 48 

 moves by scow in 50 days, that is, practically one machine was 

 moved each day. 



The number of these tractors which will be used on salt-marsh 

 drainage is decidedly limited, and it will probably be impossible 

 to induce a tractor manufacturer to build for the open market a 

 machine of such special construction. The cost of manufacture 

 by special order will, therefore, be high, but will, by increased 

 output, make a good return on the investment. 



The cleaning and maintenance of the millions of feet of 

 ditches already installed becomes each year a more serious prob- 

 lem. We have no satisfactory tools for the cleaning of all kinds 

 of ditches and no machinery for the cleaning of even the ditches 

 in good meadow. At present the scoop attached to a potato 

 drag gives the best results for removing the mud in a filled-in 



