RT Journal Article SR Electronic T1 Wave length of the D <sub>3</sub> helium line JF American Journal of Science JO Am J Sci FD American Journal of Science SP 357 OP 358 DO 10.2475/ajs.s3-50.299.357 VO s3-50 IS 299 A1 Palmer, A. DeF. YR 1895 UL http://www.ajsonline.org/content/s3-50/299/357.abstract AB