ptember upon a vertical point. The needle is thin and flat 17, 1861, and further information in relation to it bushed at the center usually with a ruby. A ship’s compass card is not made with strongly contrasting == = north and south surfaces, therefore a light is required to read it at night.… … It has settles at a point north and south. In taking an ob- servation the card is held steady by a catch plate, A vertical section of the apparatus is shown in focus. The lens is mounted in an india-rubber disk, which is operated by pressing with the finger on the at the upper end of a brass tube,…
Internet Archive · Public domain (published before 1931). Free to use for anything.
