Technical supply co., Scranton. [from old catalog] · Scranton, Pa., Technical supply co · leaf 302
3570 3575 In the hands of the prospector, the Miners Compass or Dipping Needleproves a serviceable guide to the discovery and location of magnetic iron ore.In this instrument the magnetic needle is carefully balanced upon a hori-zontal axis within a graduated circle, and in which the needle will be…
Engineering instruments · Drawing instruments
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
