AUCTION : 0518


Clock, Watch, Jewelry, Nautical Instruments & Antiques Auction

Clocks & Clockmaker's Shop featuring rare French Industrial Series
Saturday, May 19, 2018 at 10:30am: LOTS 1 - 598
Preview: Saturday, May 19 at 8am to 10:15am. Limited Watch Preview Extended Until 12pm.

Precision Timepieces, Important Watches, Nautical Instruments, Marine Clocks, Jewelry & Antiques
Sunday, May 20, 2018 at 10am: LOTS 599 - 1192
Preview: Saturday, May 19 at 8am to 10:15am & Sunday, May 20 at 8am to 9:45am 

The Manchester Downtown Hotel (formerly the Radisson Hotel), Manchester, NH

Lot#: 674

DESCRIPTION: Hall Colby, New York, "Altimeter" or gravity sextant, lacquered brass, 9.5 inch sighting tube atop a graduated brass arc reading 90 to 0 to 90. Center of arc reads "HALL COLBY / ALTIMETER / Patent Applied For / No. 21". Two vernier scales, one for the "ALTITUDE" scale showing degrees from a horizontal axis and one for the "ZENITH" scale showing degrees from a vertical axis. Free-swinging pendulum establishes a vertical line of reference against which the angles are measured. Spring-loaded pin locks pendulum when a reading has been made.
CONDITION: The initial patent in England was granted in 1855. The improved patent in the U.S. was granted in 1870. The pending patent indicated on this instrument makes this an earlier model than most examples. Lacquer has turned brown and is missing in spots. One of the screws that holds the handle on is missing. Swinging pendulum moves freely. Locking pin works. By design, the unit has no mirrors or lenses. Comes in mismatched wood case for a different type of sextant.
ESTIMATE: $800 - $1200
CIRCA: 1860
DIMENSIONS: 8in x 9.5in x 3.5in