A New or Improved Double Sextant.

摘要

13,026. Hummel, J. H. June 18. Sextants.-A double sextant for observing almost simultaneously the angles between three fixed points comprises a frame b carrying two fixed mirrors a, a1 and corresponding adjustable mirrors c, c' attached to quadrants d, d' reading against a vernier i situated under a magnifying-glass k. A spring h prevents accidental displacement of the quadrants when in use. Telescopes and other usual fittings can be employed.