Description:
This altimeter is one of a pair. They are marked “Pennwalt” “Wallace & Tiernan” Model NO FA 181000. The Pennwalt Corp. was established in 1969 so the production of these altimeters would be after that date.

From the tables on the altimeter shown, the Geodetic Survey of Canada would likely have used them for determining altitude and for determining atmospheric pressure for electronic distance measuring corrections.

Object ID:
ALSA 2016.01.05

Donated By:
The Surveyor General Branch, Natural Resources Canada.