RT Journal Article SR Electronic T1 Ogden Nicholas Rood JF American Journal of Science JO Am J Sci FD American Journal of Science SP 73 OP 77 DO 10.2475/ajs.s4-15.85.73 VO s4-15 IS 85 A1 Wright, Arthur W. YR 1903 UL http://www.ajsonline.org/content/s4-15/85/73.abstract AB