How TO MAKE A CROW-FOOT DREDGE OUTFIT, in 



Fig. 28. The "Mule." 



strength of the current in the river where the dredge is to 

 be used, and will also depend upon the number of hooks 

 to each dredge and the nature of the river bottom. 

 Usually during the spring months when the current is 

 strong a mule 2^/2 feet by 5 feet will be large enough, 

 but later in the summer when the water is lower and the 

 current is not so strong it will require a larger mule to 

 pull a large dredge. A strong but light wooden frame 

 is made and covered with a heavy cloth. The cloth should 

 be tacked on rather loosely so the water can fill in like 

 the wind in a sail. This will make it pull better. Some 

 use a piece of gas pipe or other iron along the bottom of 

 the mule to help sink it, although it is not really neces- 



