BESEAECH METHODS I^T STUDY OF FOREST ENVIRONMENT. 205 



63. Kimball, H. H. Photometric measurements of daylight illumination on a 



horizontal surface at Mount Weather, Va. U. S. Weather Bureau 

 Mo. Weather Kev., XLII, pp. 650-653. 1914. 



64. Total radiation received on horizontal surface from sun and sky at 



Mount Weather, Va. U. S. Weather Bureau Mo. Weather Rev., 

 XLII, 8, Aug. 1914, pp. 474-4S7, and XLIII, pp. 100-111, March 

 1915. 



65. Variation in the total and luminous solar radiation with geograph- 



ical position in the United States. U. S. Weather Bureau Mo. 

 Weather Rev., XLVII, pp. 769-793, Nov., 1919. 



66. Knott, C. G., Solar radiation and earth temperatures. U. S. Weather 



Bureau Mo. Weather Rev., XXXI. 10, pp. 454-459, Oct., 1903. 



67. Laxgley, S. P. Researches on solar heat and its absorption by the earth's 



atmosphere. (Mount Whitney Expedition.) Papers of the Signal 

 Service No. 15, War Dept, 18S4. 

 6S. MacDougal, D. T., and Spoehe, H. A. The measurement of light in some 

 of its more important physiological aspects. Science, n. s., vol. 

 XLV, No. 1172, June 15, 1917. 



69. Marvin, C. F. The measurement of sunshine and the preliminary examina- 



tion of Angstrom's pyrheliometer. U. S. Weather Bureau Mo. 

 Weather Rev., XXIX, Oct., 1901. 



70. Care and management of sunshine recorders. 3d ed.. 22 p. (Cir- 



cular G, Instrument Div.), U. S. Weather Bureau, 1911. 



71. Poyntixg, J. H. Radiation in the solar system. U. S. Weather Bureau 



Mo. Weather Rev., XXXII, 11, pp. 507-511, Nov., 1904. 



72. Radau. Actinometrie. Paris, 1877. 



73. Shakp, C. H., and Miller, P. S. A new universal photometer. Electrician, 



60. pp. 562-565, 1908. 



74. Very. Frank W. Atmospheric radiation. (A research conducted at Alle- 



gheny Observatory and at Providence, R. I.) 134 p. U. S. Dept. 

 of Agr. Weather Bureau Bull. G, 1900. 



75. The sohir constant. U. S. Weather Bureau Mo. Weather Rev., 



XXIX, Aug., 1901. 



76. Wkisxik. Jrr.n;s. Orientirende Versuche iiber den Einfluss der sogenannten 



chemischen Lichtintensitat auf den Gestaltungsprocess der Pflan- 

 zenorgane. (In Sitzungsberichte der K. Akademie der Wissen- 

 schaften, Wien, Mathematische-naturwissenschaftliche Klasse, vol. 

 102, pt. 1: 291-350, 1893.) 



77. Zon. Raphael A new explanation of the tolerance and intolerance of 



trees. Proc. Soc. Am. Foresters, II, 1, 1907. 



78. and Graves, II. S. Light in relation to tree growth. U. S. Forest 



Serv. Bull. 92, 1911. 

 7!». Zedebbatjeb, Emebich. J>;is Liehtbedurfniss der Waldbaume und die Licht- 

 mess Methoden. (In Centralblatt fur das gesamte Forstweson, 

 1907, vol. .".:;: 525 830. Transl. in Forestry Quarterly, vol. 6: 255- 

 262, 1908.) 



I-I:l.( IITIATION. 



81. Abbe, Cleveland. Rain gage and the wind. (Ed. Notes, Mo. Weather Rev., 



XXVII. 10, p. 464 468, <»<•(., is!)!i. 



82. Alteb, J. 0. Where the snow n<-s in summer, u. s. Weather Bureau m<>. 



Weather Rev., xxxix, pp. 7r,8 761, IB, May, 1911. 



