Cased Trough Compass by Hilger & Watts, Ltd.

Wooden Cased Trough Compass by Hilger & Watts Ltd. English-made, circa 1950.

Trough Compasses were used to accurately align other instruments such as a plane table, theodolite, etc. to magnetic north. Encased in gilded wooden box, with sliding lid. The magnetized steel needle is aligned with brass bar to locate true North (opposite end shows South). An early, pre-serialized piece by well-known, British opticians & scientific instrument makers, Hilger & Watts (1948-1967). 

Marked 'HILGER & WATTS LTD, MADE IN ENGLAND' 

Dimensions: 17.0 cm x 4.0 cm x 3.5 cm

Weight: 10.6 oz.