METEOROLOGY. 



115 



air of summer not only favors the access of light and heat, but it also permits 

 certain chemical actions necessary for fruit ripening. Moreover, a considera- 

 tion of some moment is the fact that it prevents certain fungoid diseases. . . . 

 The period of greatest fruit grovs^th is from June to October. The rest period 

 in trees and vines just following the gathering of the fruit is a dry season 

 climatically, not a cold season as in the East. . . . The soil moisture has its 

 origin in the winter rains, when the trees and vines are inactive." 



Climate of State College, Pennsylvania, W. Prear and H. D. Edmiston 

 {Pennsylvania Sta. Bpt. 1913, pp. 220-3S6, pLs. S). — This is a summary and 

 analysis of temperature records from 18S0 to 1912, but particularly of the more 

 complete records covering the years 1886 to 1912. Hourly, daily, monthly, 

 seasonal, and annual temperatures and temperature variations are considered in 

 detail. The station at which the observations were made is very near the 

 geographic center of Pennsylvania in about latitude 40° 55' N., and longitude 

 77° 51' W. The elevation above sea level is about 1,200 ft. " The location is 

 nearly 300 miles west from the Atlantic Ocean, just east of the main Appa- 

 lachian range, separated thereby both from the great central valley of the Ohio 

 and the Mississippi and also from the region of the Great Lakes ; not sheltered 

 by near-by mountains, in a country no longer densely wooded, on a swell open to 

 the full sweep of the winds, yet tempered in cold, quiet weather by the drainage 

 of the colder air into near-by hollows and vales." 



The normal course of daily temperature through the years 1886 to 1912, in- 

 clusive, is shown in the following table: 



Average daily temperature (°F.) 1886-1912. 



Days of month. 



Jan. 



Feb. 



22.2 

 25.5 

 22.8 

 22.5 

 21.7 

 21.6 

 22.8 

 24.0 

 24.0 

 24.4 

 23.6 

 24.2 

 25.7 

 27.6 

 26.9 

 25. 3 

 27.1 

 30.4 

 27.5 

 25.8 

 30.0 

 29.4 

 31.1 

 29.0 

 28.9 

 27.8 

 26.3 

 28.4 

 30.3 



Mar. 



30.0 

 31.6 

 30.2 

 29.1 

 27.0 

 30.2 

 33.6 

 33.6 

 33.6 

 34.8 

 35.3 

 37.1 

 35.5 

 33.0 

 31.2 

 31.4 

 33.3 

 36.4 

 39.1 

 38.9 

 36.3 

 37.7 

 37.9 

 38.1 

 38.1 

 38.4 

 39.6 

 40.2 

 40.2 

 41.3 

 41.1 



Apr. 



40.1 

 39.5 

 40.8 

 43.3 

 44.3 

 44.1 

 42.7 

 43.0 

 43.7 

 43.5 

 43.6 

 45.8 

 48.4 

 47.3 

 47.0 

 48.3 

 47.6 

 50.2 

 50.4 

 48.3 

 49.3 

 50.9 

 51.6 

 51.1 

 52.3 

 53.1 

 53.9 

 54.1 

 54.9 

 57.5 



May. 



59.3 

 55.1 

 55.9 

 55.1 



55.7 

 56.8 

 57.1 

 57.6 

 59.1 

 58.9 

 59. 4 

 59.7 

 59.8 

 58. 6 

 59.2 

 58.5 

 60.0 

 62.3 

 61.5 

 62.3 

 59.4 

 60.7 

 61.4 

 62.6 

 61.6 

 59.8 

 59.8 

 60.3 

 61.1 

 61.1 

 61.9 



June. 



61.8 

 63.8 

 63.9 

 65.5 

 65.7 

 64.6 

 63.7 

 64.2 

 65.3 

 64.9 

 65.5 

 65.8 

 66.4 

 68.0 

 68.6 

 67.2 

 67.3 

 67.1 

 68.0 

 69.2 

 68.7 

 68.2 

 68.7 

 69.0 

 68.8 

 69.5 

 67.3 

 67.3 

 69.0 

 69.7 



July. 



70.3 

 72.0 

 72.5 

 71.4 

 71.1 

 71.9 

 71.2 

 71.4 

 70.0 

 70.1 

 71.0 

 71.4 

 70.7 

 70.7 

 70.8 

 71.7 

 71.7 

 68.5 

 70.0 

 70.9 

 70.8 

 70.8 

 70.9 

 69.6 

 70.7 

 C9.4 

 69.2 

 70.1 

 72.1 

 71.4 

 70.9 



Aug. 



69.4 

 69.6 

 70.0 

 69.2 

 69.5 

 70.2 

 69.6 

 70.5 

 71.4 

 71.8 

 71.1 

 69.0 

 68.4 

 70.5 

 68.6 

 68.8 

 68.7 

 67.6 

 68.0 

 67.2 

 67.1 

 67.7 

 67.7 

 68.3 

 68.2 

 68.4 

 65.9 

 64.5 

 65.4 

 66.0 

 65.5 



Sept. 



65. 6 

 66.5 

 67.8 

 66.8 

 66.0 

 65.6 

 65.5 

 65.6 

 65.3 

 66.3 

 65.1 

 66.1 

 64.3 

 62.9 

 62.4 

 63.4 

 62.9 

 63.1 

 6.3.4 

 60.3 

 61.1 

 60.9 

 61.2 

 60.2 

 59.5 

 58.7 

 58.9 

 57.1 

 57.6 

 55.9 



Oct. 



55.5 

 54.7 

 54.5 

 56.1 

 56.6 

 54.3 

 52.5 

 51.8 

 52.3 

 51.3 

 54.0 

 51.5 

 50.0 

 51.1 

 51.1 

 52.4 

 51.0 

 51.7 

 51.4 

 49.8 

 47.5 

 47.4 

 48.8 

 47.2 

 47.2 

 46.9 

 47.5 

 45.4 

 44.2 

 43.2 

 45.2 



Nov. 



46.8 

 46.6 

 44.8 

 42.7 

 42.4 

 43.4 

 42.0 

 42.1 

 44.9 

 43.2 

 40.4 

 40.0 

 38.5 

 36.9 

 38.0 

 39.1 

 39.3 

 38.2 

 39.3 

 37.7 

 38.9 

 40.2 

 38.0 

 3G.3 

 35.3 

 36.0 

 36.2 

 33.2 

 33.6 

 31.8 



Dec. 



30.6 

 31.1 

 30.8 

 28.3 

 28.5 

 30.8 

 30.8 

 31.1 

 31.2 

 31.7 

 32.7 

 31.7 

 30.5 

 30.5 

 29.8 

 29.3 

 28.4 

 29.0 

 28.7 

 28.7 

 30.2 

 30.9 

 31.0 

 31.2 

 30.2 

 27.9 

 27.5 

 25.6 

 27.1 

 28.1 

 27.9 



The table shows " that, while the annual course of temperature from season 

 to season through the year is primarily determined by the increase and later by 

 the decrease in length of the corresponding daylight periods, the influence of 



