General Information

Serial #

N/A

Part Number

1

Total Parts

3

AKA

N/A

Patents

N/A

General Description

Instrument- brass frame & index arm; ivory veneer & scale; glass eyepiece, filters & mirror; boxwood handle/ case- mahogany with brass hardware

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

26.5 cm

Width

23.5 cm

Height

8.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Marine Transportation

Category

Navigation instruments & equipment

Sub-Category

N/A

Manufacturer

AKA

Black Murray

Country

India

State/Province

Unknown

City

Calcutta

Context

Country

Unknown

State/Province

Unknown

Period

Unknown

Canada

Unknown

Function

An instrument having an arc of 24 degrees used by navigators for measuring angles. T-frame navigating octant, used for marine navigation. The octant is set up as an eighth of a circle, and a series of reflecting mirrors is used to line up a celestial body with the horizon line. The angles measured can be converted to latitude and longitude.

Technical

Manufactured by Black & Murray. Scale reads from -10 degrees to 110 degrees, and vernier reads to 20 degrees. Octants made it possible to view and measure the angle between two different objects.

Area Notes

Unknown

Details

Markings

Stamped 'BLACK & MURRAY, CALCUTTA, INDIA; CHRONOMETER, WATCH, CLOCK & SCIENTIFIC INSTRUMENT MAKERS, CHART. AGENTS TO THE ADMIRALTY & GOVERNMENT OF INDIA'

Missing

Instrument appears complete, case missing key

Finish

Instrument- brass has a flat black finish except on arc/ case- varnished

Decoration

Brass trade plaque applied to interior of case