° 59 
Monthly and annual means of noonday readings of a Fahrenheit thermometer 
whose bulb is 1 inch below the surface of the soil at Greenwich Observatory. 
Year. Jan. | Feb. pee Apr. | May. June. July.| Aug. Sept. Oct. | Nov. Dec. [ecual 
| | | | | | : 
iS ate 37.8 | 38.0 | 42.9 | 47.2 | 58.0 | 61.1 | 67.4 | 64.7 | 56.9 | 54.5 | 48.7 | 445] 51.81 
deta: tea ste 37.4 | 44.1 | 44.6 | 49.5 | 61.6 | 61.7 | 65.0 | 60.8 [058.8 | 53.5 | 45.5 | 45.5] 52.38 
esas 8 Ech. 41.5 | 43.6 | 44.3 | 46.3 | 56.5 | 63.3 | 65.0 | 65.2 | 61.8 | 53.0 | 46.5 | 411) 52.34 
TESORO 3 2s 36.7 | 44.4 | 41.9 | 50.4 | 53.0 | 64.1 | 65.2 | 63.0 | 58.7 | 49.5 | 48.7 | 42.7] 51.52 
copie es ns 44.2 | 42.7 | 44.0 | 48.5 | 54.8 | 62.2 | 63.8 | 65.5 | 60.0 | 54.7 | 41.2 | 42.2] 51.98 
Ai baa 42.8 | 42.0 | 43.0 | 49.9 | 55.1 | 59.4 | 71.0 | 65.2 | 61.1 | 50.2 | 50.4 | 48.0] 53.18 
Piieriees, 8s, | 44.3 | 37.0 | 41.8 | 47.4 | 55.7 | 62.3 | 63.2 | 64.1 | 60.3 | 55.1 | 44.9] 38.0] 51.18 
oe ee 40.6 | 41.6 | 45.3 | 52.7 | 54.2) 59.8 | 644 | 64.6 | 61.6 | 52.9 | 44.1 | 42.9) 52.06 
ae ea ae 38.4 | 33.4 | 41.0 | 48.9 | 52.9 | 61.3 | 65.6 | 66.0 | 60.9 | 54.7 | 44.3 38.3] 50.47 
rE aes oa 41.5 43.3 | 41.7 | 50.4 | 52.6 | 63.0 | 64.8 | 66.7 59.0 54.5 43.9 41.9] 51.94 
CVC e oe eee 38.9 | 40.7 | 43.7 | 48.3 | 57.6 | 65.6 | 67.0 | 67.9 | 62.5 | 55.2) 48.8) 46.6) 53.57 
(pacts ees 39.6 | 37.8 | 42.2 | 49.6 | 54.3 | 68.6 | 64.5 | 66.0 | 62.7 | 54.2 | 42.2 | 42.4] 52.01 
Aer tears he 42.4 | 43.5 | 47.3 | 49.3 | 55.8 | 64.4 | 70.7 | 66.7 | 59.7 | 54.4 | 44.3 99.3] 53.15 
1) se ae Agee 40.9 | 87.4 | 42.1 | 45.2 | 56.7 | 58.2 | 61.3 | 60.4 | 57.0 | 52.4 | 44.0] 30.9| 49.62 
PSE 3 g-----| 35.5 | 42.6 | 44.6 | 47.7 | 54.9 | 63.2 | 64.6 | 66.2 | 60.3 [57.5 | 43.9 | 42.6 | 51.97 
(at) are ae | 40.7 | 42.9 | 45.6 | 50.6 | 57.8 | 60.0 | 62.6 | 63.5 ; 60.6 | 54.3 | 42.7 | 44.0) 52.11 
3c la 43.2 | 43.2 45.0) 51.1 54.3 | 60.5 | 64.0 | 63.9 | 57.6 | 54.3 48.0 | 45.6 52.56 
1 eae ae 39.6 | 39.0 | 43.2 | 50.0 | 56.3 | 60.0 | 63.2 | 62.2 | 59.5 | 54.0 | 45.4 | 41.6 | 51.17 
ich os es 38.8 | 38.9 | 89.3.) 53.3 | 57.8 | 64.4 | 66.1 | 62.5 | 65.6 | 54.7 | 47.5 | 45.1) 51.88 
[Oi eee 44.1 | 43.1 | 42.0 | 50.3 | 52.8 | 63.3 | 65.0 | 61.7 | 59.0 | 55.2 | 47.2 | 44.9 | 52.38 
ieee ee. he! 38.3 | 46.1 | 40.7 | 49.9 | 55.9 | 61.4 | 62.6 | 64.1 | 60.5 | 52.6 | 45.2 |:39.9| 51.43 
Leesan BYR e ee, 39.4 | 44.5 | 45.9 | 50.5 | 59.8 | 64.3 | 69.9 | 66.7 | 63.0 | 52.2 | 45.0 | 47.0) 54.02 
iL ay ear 43.0 | 46.8 | 40°S | 51.5 | 54.3 | 58.6 | 66.2 | 63.2 | 60.9 | 52.4 | 45.8 | 40.5 | 52.00 
TC ia 40.1 | 38.1 | 42.5 | 50.0 | 56.1 | 64.2 | 67.1 | 63.8 | 58.6 | 52.9 | 44.3 | 88.14 51.32 
SHES ese ie 36.2 | 42.0 | 45.0 | 49.6 | 54.2 | 58.4 | 63.7 | 66.6 | 60.7 | 52.0 | 41.2 | 39.2| 50.73 
Neypere os. 7tL hs 41.6 | 44.6 | 45.0 | 49.8) 53.4 61.5 | 66.9 | 63.9 60.6 | 50.8 | 47.1 43.0 52.36 
1873___.-.....--...] 42.8 | 36.4 | 42.4 | 48.5 | 53.3 | 61.2 | 66.0 | 65.2 | 57.7 | 51.4 | 45.7 | 42.7 | 51.11 
Average __| 40.38) 41.40) 43.25, 49.50) 55.54) 62.08| 65.44) 64.46) 60.21) 53.45] 45.43 42.50 51.97 
SOIL TEMPERATURES OBSERVED AT BROOKINGS, S. DAK. 
Among the agricultural experiment stations in the United States 
whose work will be used in this preliminary report are some whose 
observations of the temperature of the soil will be needed for com- 
parison with the observations on the growth of plants and resulting 
crops or for demonstrations of the relations between the temperature 
of the air and of the soil. The following table gives for Brookings, 
S. Dak., the daily maximum readings of the thermometer in the air 
and shade, the daily rainfall, the maximum temperatures of the soil 
at depths of 2 inches and 12 inches as far as published in Experiment 
Station Bulletin No. 6 for a portion of the summer of 1888. These 
figures show that in summer and for the growing season generally 
the temperature of the soil near the surface is higher than that of 
the air in the shade only when the sun shines on it, and that it is 
lower than the temperature of the air in the shade only when the 
radiation cools it at nighttime or when the rain falls in the daytime 
and is for a short time followed by rapid evaporation. The average 
