General Information

Serial #

N/A

Part Number

1

Total Parts

7

AKA

N/A

Patents

N/A

General Description

Bright brass instrument has glass and silvered mirrors and lenses; ebony [?] wood grip; vernier and arc scales divided on ivory [?].

Dimensions

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

Length

24.3 cm

Width

23.5 cm

Height

9.5 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

McMillan Talbott

Country

England

State/Province

Unknown

City

London

Context

Country

Unknown

State/Province

Unknown

Period

Unknown

Canada

This instrument was purchased by Mr. Douglas Hearnshaw, naval architect in Montreal in the 1950s. Given Mr. Hearnshaw’s background as a naval architect, the sextant was probably purchased as an atmosphere or collection piece rather than for its original function. Two publications of the Canadian Naval Technical History Association, “The Story of the DDH 280 Program” and the “Shipyards of the Canadian Naval Shipbuilding Program 1939-2000”, indicate that Mr. Hearnshaw was employed as a naval architect at Canadian Vickers. [Ref. 1]

Function

Used to establish one’s position (latitude & longitude) by measuring the angular distance between celestial objects (moon and the sun, a star or planet).

Technical

The sextant was the main tool of the navigator. Developed from the more limited octant in the 1760s, the sextant could be used either to find the height of the Sun above the horizon to determine a ship’s latitude, or measure angles between the Moon and fixed stars. The latter was a more difficult observation to do accurately on a moving vessel but, using published tables, allowed a skilled navigator to calculate his longitude as well. [Ref. 2]

Area Notes

Unknown

Details

Markings

"McMillan & Talbott, 13 Tower Hill, London" etched on lower edge of arc face. Arc scale labelled 0 to 135 at intervals of 5; divided from -5 to 135 in increments of .25 . Vernier scale labelled 0 to 15 at intervals of 5; divided from 0 to 15 in increments of .50.

Missing

Unknown: appears complete. Some minor damage/loss to vernier scale noted.

Finish

Bright brass instrument has glass and silvered mirrors and lenses; ebony [?] wood grip; vernier and arc scales divided on ivory [?].

Decoration

N/A