Optical balance level
- PART OF:
- Optical balance level
Optical balance level, after a type used in the 17th Century, British, 1700-1799
Levelling is the method used by surveyors to determine the relative heights of different points on the earth's surface, but originally referred to the simple procedure of determining the horizontal. This crude instrument has a lead tube hanging from a fixed thread inside a protective case, with a slit at one end and a cross-hair at the other. The device would have been so easily disturbed that its use would have been extremely limited.
Details
- Category:
- Surveying
- Object Number:
- 1913-258/1
- Materials:
- lead (metal), mahogany (wood), wood (unidentified), wood veneer, iron, steel (metal), glass and brass (copper, zinc alloy)
- Measurements:
-
Overall: 245 mm x 180 mm x 100 mm, .965 kg
- type:
- level
- credit:
- Court, Thomas Henry
