14 



MASS. EXPERIMENT STATION BULLETIN 447 



Fig. 11. 



A. A Bulkhead and Sewer Pipe Water Gate. 



B. An Open Gate. The upright timbers extend well above the top of the dam to permit building 

 the dam higher if this is found desirable. 



Sand 



Sand is used as a mulch before the vines are set and for resanding in after years. 

 Fine sand promotes the growth of moss and allows weeds to thri\e more than 

 coarse sand. Sand screened from gravel is very satisfactory. 



On Cape Cod, where sand abounds around the swamps (Figs. 19B and 28) ^ 

 it usually is carried on to the bog over a line of planks by men with special wheel- 

 barrows that have a pneumatic tire and balance the load over the wheel (Fig. 12) ; 



