Frosts in New York 



S17 



ing the dry vines and furnishing a reservoir for the storage of heat received 

 by day against the low temperatures at night. 



Professor Cox made a series of observations on the temperature of the 

 air over peat and sanded bogs five inches above the surface at Cranmoor, 

 Mather, and Berlin, Wis., of which he says: 



For two months the (night) temperature over the sanded bog averaged 

 higher than over the peat bog, as follows: Cranmoor, 5.3°, Mather, 4.4°, 

 and Berlin, 5.4°; the greatest daily difference was n° at Cranmoor on 

 August 30 and at Mather on September 15, and 19° at Berlin on August 

 II. At no time did the minimum temperature over peat register higher 

 than over sand at any one of the three stations. There were several 

 dates, however, when there was no difference in the readings of the instru- 

 ments over the peat and over the sand. This occurred invariably on 

 cloudy nights when the temperatiire was high and there was no danger 

 from frost. 



Dewey A. Seeley, in investigating the effect of surface covering 

 on temperature at Peoria, 111., exposed four minimum thermometers as 

 follows: No. I, about half an inch below the surface of bare ground; 

 No. 2, on the surface of bare ground; No. 3, half an inch below the surface 

 of sod; No. 4, on the surface of sod. The four instruments were read 

 on eighteen mornings after clear, quiet nights, also on thirteen afternoons 

 v/hen the weather was clear and the wind light. The results obtained were 

 as follows: 



Mr. Seeley calls attention to the fact that, although the soil under sod 

 was warmest at night, its surface was coldest, the difference being sur- 

 prisingly large, 12.3°, within the distance of about one inch between the two 

 thermometers. This seems to indicate that comparatively little heat 

 escapes through the sod covering at night, and that the loss of heat from 

 the surface of the sod is very great. It is pointed out also that the tem- 

 perature over sod was 3.4° below the temperature recorded over bare 

 ground, indicating that the heat given off by the bare ground during the 

 night was effective in raising the temperature of the air in contact with 



