Plane Table, Compass, Trough

Compass, Trough ALSA 2013.01.02
Compass, Trough ALSA 2007.28.02
Compass, Trough ALSA 2012.01.01

Description:

  • Object ID: ALSA 2013.01.02
  • Made by: Unknown.
  • Model: Unknown.
  • Serial Number: Unknown.
  • Date Made: Unknown.
  • Approximate size: 12 cm long X 1.5 X 1.7 cm.
  • Accessories: Unknown.
  • Condition: good

Commentary:

It is also called a plane table compass or declinator. It is used to mark magnetic north on the plotting paper on the plane table drawing board. 12 cm long X 1.5 X 1.7 cm. Lever to lock compass needle on side.

Source of Object: Donated by Lou Breton, ALS.

Notes: The Society has two other Trough Compasses, ALSA 2007.28.02 (Weir) and ALSA 2012.01.01 (Frederick).

References: Visit article The Survey Instrument Captain Cook Wanted to Learn – The Plane Table and Alidade for additional information.

Description by: Entered by Ed Titanich on December 23, 2024.