octant
Date1750
Inventory Number5303
ClassificationOctant
Subject
Maker
English
Owner
Captain Alexander Caldwell
fl. 1750
Cultural Region
Dimensions38.8 x 28.8 x 7.7 cm (15 1/4 x 11 5/16 x 3 1/16 in.)
Material
DescriptionThis is an octant with a thick frame, mostly made of mahogany. The flat, broad index arm is made of lignum vitae with the end covered in brass. The limb is made of applewood covered with brass plating decorated around the edges with a herringbone pattern. The scale is divided 0°-90° every 30' with transversals every 30'. The index arm has a vertical index subdivided into 3-minute intervals.
There is an adjustable index mirror and a horizon glass, but the shades are missing. There is a sight with two pinholes.
There is an adjustable index mirror and a horizon glass, but the shades are missing. There is a sight with two pinholes.
Signedon index arm: Capt / Alexander Caldwell / 1750
Historical AttributesAccording to the <i>Dictionary of National Biography</i>, Captain Alexander Caldwell was the fifth and youngest son of Sir John Caldwell, second baronet, of Castle Caldwell, county Fermanagh, Ireland.
A note in the file from past curator Ebenezer Gay says that Caldwell was a Philadelphia shipmaster; this could not be confirmed.
E. & G. W. Blunt
Date: 1825-1860
Accessories: Keystone box (1996-1-0172b).
Object number: 1996-1-0172a
Benjamin Martin
Date: 1764
Accessories: small brass scope with brass and ivory holder.
Object number: 0007
Joseph Sewill
Date: circa 1850
Accessories: Keystone mahogany box, sight tube, adjustment tool, (telescope missing)
Object number: 5334