114 MASS. EXPERIMENT STATION BULLETIN 160. 



elevation of wliich was regarded as 100 feet. It was practically the same 

 in hole No. 6. The pump was run for one and one-quarter hours, until 

 10.45 A.M., when holes Nos. 1 and 2 on one side of the section and Nos. 

 11 and 12 on the other side were fuU of water which had run over the 

 surface of the sand into them. The water level in the ditches and these 

 holes was then, as measured from the bench mark, 98.75. The surface 

 water had not run into the other holes at all or come anywhere near 

 them. At noon, one and one-quarter hours after the pumping was done, 

 the water levels in the 12 holes and in the ditches were taken and found 

 to be as follows : — 



This record shows a variation of only about 6% inches in the water 

 level two and one-half hours after the pumping was begun. Similar meas- 

 urements were made again at 3.30 p.m., six hours after beginning pumping 

 and four and three-quarters hours after stopping, and the variation was 

 then found to be onl}^ about 1% inches, the various levels being as fol- 

 lows : — 



The pump was started again at 4.20 p.m. (May 29) and run until 7 p.m. 

 The planks were then put in, and all the water was held until 2 a.m. the 

 following morning, at which time the water level on the bog was 99, all 

 the 12 holes used in making the above measurements being entirely full. 

 The water was allowed to run out of the bog freely from 2 a.m. until 

 10.45 A.M., when the levels in the ditches and in the holes were again 

 taken and found to be as follows : — 



