RT Journal Article SR Electronic T1 Measures of the intensity of solar radiation JF American Journal of Science JO Am J Sci FD American Journal of Science SP 378 OP 386 DO 10.2475/ajs.s3-41.245.378 VO s3-41 IS 245 A1 Ferrel, William YR 1891 UL http://www.ajsonline.org/content/s3-41/245/378.abstract AB