Instrument	:	Octant
Manufacturer	:	Unknown
Country of origin	:	U.K.
Manufacturing year	:	First quarter 19th century

I've obtained this octant in 2001. The octant was the successor of the backstaff and the predecessor of the sextant and pentant. The term 'octant' comes from the fact that the instruments arc covers 1/8^th of a circle (=45º). The use of the mirror on the index arm multiplies this by 2, so an angle of up to 90º can be measured.

Although the octant was the first succesfull double reflecting instrument it was not the first reflecting navigational instrument. The first navigational instrument equipped with a mirror was the spiegelboog, invented in 1660 by the Dutchman Joost van Breen. The octant was invented in 1731 by John Hadley. Before Hadley others too invented reflecting instruments, like Robert Hooke in 1666 (a single reflecting instrument) and Sir Isaac Newton in 1699 (a double reflecting instrument), but these never became widely used.

As the instruments box was signed and the manufacturers nameplate was missing I started a queste to get to know it better.
So far I've found out the following:

• Possible owner was Captain Denison (sometimes spelled with two 'n's), master of the brig Mary Stewart in 1858.[MS.WS]
• The brig Mary Stewart was built by T. Crosby in Bangor, Maine in 1856 and owned by T. Stewart of Bangor[MS.WS]
• It looks like the step box is made of oak, indicating that it would be Brittish (so would be the instrument when it belongs to the box).[MS.WS]
• Frederick W. Lincoln (b. 1817), a grandson of Paul Revere, was apprenticed to Gedney King, instrument maker of Boston, in 1830. Lincoln set up in business in 1839, and until 1853 was at 62 Commercial St., and then until 1856 at 136 Commercial St. In 1858 one of his apprentices, Charles C. Hutchinson, became a partner, and it was at this point that the firm became known as Frederick W. Lincoln, Jr. and Co. and moved to 126 Commercial St.[MS.WS]
• In 1848, Aaron Breed, mathematical instrument maker, lived at 138 Purchase Street in a building owned by Jotham Bush. His shop was located in the building at the corner of Broad and Purchase Street owned by Frederick Clapp. His shop was in the same location in 1847 and 1849. The earliest tax records we have here at the City Archives are from 1822. I did find Aaron Breed listed in 1822 as a "Jy Mathematical Instrument Maker". In 1823, he has a shop at India Wharf and Broad St. The latest that I found him was 1860. He was listed at 1 Lincoln St. as a "Gentleman". At the same address, George W. Choate, "Jy. Mathematical Instrument Maker" was also listed. I did not find any listing after 1860 for Aaron Breed.[KS]
• Instrument is probably English, first quarter nineteenth century, resold by Lincoln, not made by him, seems to fit the box nicely, the square tool is totally unrelated to the instrument.[PI]
• instrument looks identical to an octant identified as made by S. Heilbuth, London, currently for sale at e-bay as lot nr. 3704078377. [DC]

I'm still looking for the following answers regarding this instrument:

1. The manufacturing date of this instrument
2. Who is the manufacturer?