The Mosquitoes of New Jersey 



69 



Early in the salt-marsh trenching it was recognized that the type 

 of outlet was of supreme importance and recent experience has 

 served to confirm this notion. The greater the tide drop and the 

 shorter the ditch the greater is its efficiency and its ability to keep 

 clean. Every ditch should have a strong tidal outlet and no ditch 

 depending on a single outlet should be over ^ mile long. 



The machinery used in cutting ditches has undergone some im- 

 portant changes. The hand tools have made little if any advance. 







Fig. 38. Types of tools used. The Eaton spades. 



The Manahan and the Skinner types of spades are still the prevalent 

 tools and are so covered with patents that the trenching of the marsh 

 by anyone not possessing the right to use these tools is both difficult 

 and expensive. Recently Harold I. Eaton invented a practicable sort 

 ■of hand spade but as a patent has been placed upon it the general 

 public does not seem to be in a way to benefit by it materially. 



A power machine has been invented by Mr. Eaton which unques- 

 tionably trenches the marsh with such ease and speed as to make a 

 notable reduction in the cost of ditching. Essentially, the machine 

 consists of a gasoline power plant placed on a pair of 12-foot long, 

 i2-thick planks that are set within 5 feet of each other and strongly 



