RT Journal Article SR Electronic T1 THE MOTION OF A GRAVITATING NEEDLE JF Science JO Science FD American Association for the Advancement of Science SP 214 OP 216 DO 10.1126/science.50.1287.214 VO 50 IS 1287 A1 Barus, Carl YR 1919 UL http://science.sciencemag.org/content/50/1287/214.abstract AB