566 NEW JEESEY AGKICULTUKAL COLLEGE 



derived from a large stream. In a current the water was always two 

 degrees colder than in a stagnant area, and a shallow Lad as great an 

 advantage over a deep pool. Where one foot was the depth of the 

 water, the temperature at that depth was from two degrees to four 

 degrees higher than at one foot, with three or four feet of water as the 

 depth of the pond. At a gate the water was alwa3-s a little lower in 

 temperature at the same depth than in any other portion of the bog. 

 Temperatures taken in the swamps and ditches from which the bogs 

 w^ere supplied were like those at three feet depth, and may be consid- 

 ered the ground warmth. They varied little, no matter what the air 

 temperature might be. Locality had little effect on the deep water. 

 May 6th, the Jamesburg, White, Budd and Eider bogs varied less than 

 two degrees at three feet, and very little more at the surface. The 

 records are not entirely comparable, because the dates on which obser- 

 vations were made were not identical; but here the records of the 

 State Weather Service are brought into comparison, and the inter- 

 vening dates are tilled in from Hightstown, which is only a few miles 

 from Jamesburg, and Lakewood, which is in a territory similar to 

 the other bogs. Surface temperatures ranged from 48° to 74° be- 

 tween April 19th and May 20th, and while usually from 5° to 10° 

 below the air temperature, were on one or two occasions from 2° to 3° 

 above it. This came when after a very warm day came an abnor- 

 mally cool one, the water, even at the surface, responding slowly to 

 the change. Eeadings were taken in all cases of the air temperature; 

 of the surface water, the bulb only being submerged; then at six, 

 twelve, twenty-four and thirty-six inches. Additional readings at 

 extreme depths on the bogs varied nothing from the three-foot depth. 



