Antique Sextant by Dobbie McInnes Ltd, London.

ANTIQUE SEXTANT. No.30

A large sized early 20th century navigators Sextant with the classic triangle frame design. Beautifully hand engraved on the arc Dobbie McInnes Ltd, London.

The Sextant was invented by Admiral John Campbell in 1757 after he discovered that the Octant was unable to measure angles large enough for Lunar distances ( Distance between Moon, Sun or Stars ) so he increased the 90 degree angle of the Octant to 120 degrees which formed the Sextant. He then engaged the nautical instrument maker John Bird to construct the first Sextant in 1759.

The Sextant gets its name from the Latin word for 'a sixth' because it is a sixth of a circle (60 degrees) and can measures angles of up to 120 degrees.

The silver scale is engraved from -5 degrees to 150 degrees and can measure angles up to 133 degrees, the scale is divided into 10 minute increments. The index arm has swinging scale magnifier and the silver Vernier scale reads from 0 to 10 seconds of arc.

Sextant Radius: 8 inch / 20cm.

Height of Sextant frame: 10.5 inches / 26.5cm

Width of Sextant frame:

Box measures: 11x12 inches / 28x30 cm

It is contained within its original fitted hardwood storage box. It is complete with - Four telescopes, 1 x spare telescope eyepiece and 2 x telescope sun filters. ( the minature screwdriver and magnifiying glass are both missing, this is common because they have usually been 'borrowed' and never put back )

The company was established by Alexander Dobbie in 1841, after his death in 1881 the name changed to Alexander Dobbie & Son. In 1896 the company was incorporated as Alexander Dobbie & Son Ltd, after purchasing Walker & Son, McInnes & Co and McGregor and Co the name was changed to Dobbie McInnes Ltd in 1902.

This antique celestial navigation instrument is in good condition considering it is over 120 years old. It is beautifully engineered and made using word class engineering skills, British navigational instrument makers were reputed to have made the best and most accurate instruments in the world.

Clipper Maritime Antiques specialises in antique navigation instruments. We offer a wide selection of top quality antique Sextant’s, Quintant’s and Octant’s, prices range from £300 to over £1000.

Price on request: Please Email us your enquiry or if you would like any help or advice about choosing an antique celestial navigation instrument.