octant
Date: 1860-1880
Inventory Number: 5247
Classification: Octant
Subject:
Maker: Thomas L. Ainsley (fl. 1858 - 1886)
Repaired by: Newton Brothers (fl. 1870 - 1910)
Cultural Region:
Place of Origin:
Dimensions:
28 x 23 x 26 cm (11 x 9 1/16 x 10 1/4 in.)
box: 8 x 28 x 30 cm (3 1/8 x 11 x 11 13/16 in.)
From tip to tip / cord of: 23 cm (9 1/16 in.)
Index arm to Vernier scale: 26 cm (10 1/4 in.)
top of instrument to bottom of instrument: 28 cm (11 in.)
Accessories: box
Description:
This octant has a T-form, ebony frame and a curved crossbow with an inlaid ivory name plate. There is a reinforced brass index arm with an ivory vernier scale. The limb has an ivory scale divided -4° - 108° every 20', with the vernier divided 0-20' every 1'.
It has an adjustable index mirror with three square shades, as well as an adjustable horizon glass operated by a tangential rack and pinion thumb screw which moves a small plate. The front sight is a plain pinhole with a cover; the back sight has two pinholes and a cover. There is a slow-motion tangent screw and clamp on the index arm. The instrument has feet.
With keystone case.
It has an adjustable index mirror with three square shades, as well as an adjustable horizon glass operated by a tangential rack and pinion thumb screw which moves a small plate. The front sight is a plain pinhole with a cover; the back sight has two pinholes and a cover. There is a slow-motion tangent screw and clamp on the index arm. The instrument has feet.
With keystone case.
Signedstamped on ivory nameplate: T. L. AINSLEY / South Shields
on tradecard in case: NEWTON BROTHERS / .../ II, Prince's Dock Walls, Hull.
on tradecard in case: NEWTON BROTHERS / .../ II, Prince's Dock Walls, Hull.
ProvenancePresented by David P. Wheatland, 1977.
Bought from Roux Devilla, 7-27-66.
Bought from Roux Devilla, 7-27-66.