William Harkness portrait in his naval uniform. Harkness' research with the Naval Observatory was instrumental in the understanding of discrepancies in magnetic compass readings aboard ironclad ships, and his tracking of solar parallaxes and their related constants are still impactful to the field of astronomy. The Navy honored Harkness with the honorary rank of rear admiral following his retirement after 37 years of dedicated service. (Photo courtesy of Popular Science for May, 1903)