788 



EXPERIMENT STATION RECORD. 



Prediction of night frosts in the spring, C. Housseatt (7?a'. Rort., 

 67 {l<s'J5), xW>. .5, i>y>. 71-74). — The results of observations froiiu March 

 20 to May 20 during the years 188()-'94: are reported, showing that the 

 average difference between the reading of the wet bulb thermometer 

 during the afternoon and the minimum thermometer the following night 

 was 4.8^ C, thus in a measure confirming the accuracy of Hammer- 

 manu's statement that frost may be expected if the reading of the wet- 

 bulb thermometer in the afternoon minus 4° is or less. A closer 

 analysis of the results, however, shows that this factor is by no means 

 constant, but depends largely upon direction of tlie wind, cloudiness, 

 rainfall, etc. 



The use of a somewhat larger factor than 4° is recommended as gen- 

 erally safer in iiractice. In fair weather, with the wind north or north- 

 east, the difference is nearer 7 or 8 than 4^. 



Meteorological observations at Berkeley, California, L. E. Hunt 

 [California Sia. Rpt. 1S93 and 1894,2). Siix-'). — A synopsis of observations 

 for 7 years ending June 30, 1894, on air pressure, temperature, precipi- 

 tation, humidity, cloudiuess, and direction of wiud. The summary for 

 the year ending June 30, 1894, is as follows: Pressure (inches). — Mean, 

 30.059; highest, 30.440 (Dec. 28); lowest, 29.682 (Feb. 12); yearly 

 range, 0.758; highest monthly average, 30.183 (December); lowest 

 monthly average, 29.921 (August). Temperature (°F.). — Mean of the 

 year, 50.2; mean of the warmest month, 59 (July); mean of the coldest 

 month, 44.2 (January); maximum, 79.5 (April 19); mininuim, 31 (Jan- 

 uary 0); yearly range, 48.5; greatest monthly variation, 40 (April); least 

 monthly variation, 25 (September) ; mean daily range, 14.4; mean lowest, 

 47.7; mean highest, 62.1. Precipitation (inches). — Total rainfall, 2(!.(550; 

 dew and fog, 0.084. Humidity. — INIean relative, 82.8; greatest monthly 

 variation, 52 (November) ; least monthly variation, 26 (August) ; maxi- 

 mum, 97 (l^ovember 24, 8 a. m.); minimum, 45 (November 17, 8 a. m.); 

 yearly range, 52. Weather. — Number of clear days, 163 ; number of fair 

 days, 93; number of cloudy days, 109; number of foggy days, 107; 

 number of days on which rain fell, 68. Wind. — Prevailing direction, 

 southerly. 



Report of meteorologist, W. H. Bishop [Delaware Sta. Rpt. 1893, 

 pp. 203-217). — Monthly summaries of observations at 6 stations in the 

 State on temperature, pressure, and rainfall are given. A summary of 

 temperature and rainfall observations for the year 1893 is given in the 

 following table: 



Aixnual summary of meteorological obseri'ations in Delaware. 



Tenipci-aturc (°F) : 



Uigliest 



I>o west 



Mean 



KaiiifaU (inrhns), total 



K umber of days on wliich 0.01 inch 

 or more of rain fell 



Newark. 



Middle- 

 town. 



97.00 



- 9.00 



50.90 



36.29 



87 



96.00 



— 5.00 



51.30 



41.15 



91 



Dover. 



101.00 



— 6.00 



52. 50 



42.10 



92 



Milford. Seaford. 



95. 00 ' 97. 00 



- 9. 00 1 — 5. 50 



53. 80 ! 53. GO 



40. 45 I 40. 62 



94 89 



Millsboro. 



97.00 

 17.00 

 53.50 

 44.02 



101 



