204 BULLETIN 1059, U. S. DEPARTMENT OE AGRICULTURE. 



SOIL TEMPERATURES. 



40. Abbe, Cleveland. First report on the relations between climate and crops. 



U. S. Weather Bur. Bull. 36, 1905. 



41. Botjyotjcos, G. J. Effect of temperature on the movement of water vapor 



and capillary moisture in soils. U. S. Dept. Agr., Jour. Agr. Res., 

 V, 4, 1915. 



42. Soil temperature. Mich. Agr. Exp. Station Tech. Bull. 26, 1916. 



43 Ferrel, Wm. Temperature of the atmosphere and the earth's surface. 

 U. S. Signal Serv., War. Dept., Prof. Paper 13, 1884. 



44. Hartley, Carl. Stem lesions caused by excessive heat. U. S. Dept. Agr., 



Jour. Agr. Research, XIV, 13, 1918. 



45. MacDottgal, D. T. Soil temperature and vegetation. U. S. Weather Bu- 



reau Mo. Weather Rev., XXXI, 8, 1903. 



46. Oscamp, J. Soil temperatures as influenced by cultural methods. U. S. 



Dept. Agr., Jour. Agr. Research, V, 4, 1915. 



47. Patten, H. E. Heat transference in soils. U. S. Dept. Agr., Bur. of Soils, 



Bull. 59, 1909. 



48. Seeley, D. A. Temperature of the soil and surface of the ground. U. S. 



Weather Bureau, Mo. Weather Rev., XXIX, 11, 1901. 



SOLAR RADIATION LIGHT. 



50. Abbot, C. G., and Aldbich, L. B. Smithsonian pyrheliometry revised. 



Smithsonian Misc. Coll., vol. 60, No. 18, 1913. 



51. Angstrom, A. A new instrument for measuring sky radiation. U. S. 



Weather Bureau Mo. Weather Rev., XLVII, pp. 795-797, Nov., 

 1919. 



52. Baly, E. C. C. Spectroscopy, pp. 568, Longmans, London and New York, 



1905. 



53. Bigelow, F. H. Mr. Abbot's theory of the pyrheliometer. Science, n. s., 



vol. XLVIII, Oct. 25, 1918. 



54. Briggs, L. J. A mechanical differential telethermograph and some of its 



applications. Jour. Wash. Acad. Science, vol. 3, No. 2, 1913. 



55. Btjnsen, R. and Roscoe H. Meteorologische lichtmessungen. Poggendorff's 



Annalen, vol. 117, 1862. 

 55^. Burns, G. P. Studies on the tolerance of New England forest trees. 



56. I. Development of white pine seedlings in nursery beds. Vt. Agr. 



Exp. Sta. Bull. 178, 1914. 



57. II. Relation of shade to evaporation and transpiration in nursery 



beds. Vt. Agr. Exp. Sta. Bull. 181, 1914. 



58. III. Discontinuous light in forests. Vt. Agr. Exp. Sta. Bull. 193, 



1916. 



59. Tolerance of forest trees and its relation to forest succession. Jour. 



of Forestry XVIII, 6, 1920. 



60. Clements, F. E. The life history of lodgepole burn forests. U. S. Forest 



Serv. Bull. 79, 1910. 



61. Davis, Harvey N. Observations of solar radiation with Angstrom pyrhelio- 



meter. Providence, R. I., Mo. Weather Rev. XXXI, 6, pp. 275- 

 280, June, 1903. 



62. Kimball, H. H. Observations of solar radiation with Angstrom pyrheliom- 



eter, Asheville and Black Mountain, N. C. U. S. Weather Bureau 

 Mo. Weather Rev., XXXI, 7, pp. 320-334, July, 1903. 



