Wm. Bond & Son Box Chronometer


This instrument is a specialized timekeeper originally designed for finding longitude at sea and later used everywhere as a source of portable precise time. It has an English-made chronometer movement, finished by the firm William Bond & Son of Boston and fitted with the Bond break-circuit device, electrical equipment to permit the telegraphing of time signals. The Smithsonian’s Astrophysical Observatory used the instrument. The chronometer’s wooden box fits into a padded basket for extra protection.

Mechanism details:

Escapement: Earnshaw, spring detent, later pattern

Duration: 56-hour

Power source: Spring drive with chain and fuse

Bowl details:

Brass bowl

Brass gimbals

Bezel screwed and milled

Crystal flat and plain

Dial details:

Engraved and silvered brass

Indicates hours, minutes, seconds, winding level up and down, 24-hour dial

Inscription: "WM. BOND & SON, / Boston. No. 586" on dial; "WM. BOND & SON'S, BREAKCIRCUIT. / U. S. A." on silvered inside of bezel

Hands: Gold, spade, with blued seconds and Up & Down hands

Case details:

Box: solid wood, three-part, glazed center section

Brass corners

Mother of pearl key escutcheon

Inscriptions: "WM. BOND & SON. / Boston. No 521 / BREAK CIRCUIT" on nameplate

"BOND / 521" on small oval plate in bottom of box

Carrying case: Basket, with padding


1. Gould, Rupert T. The Marine Chronometer. London: Holland Press, 1960.

2. Whitney, Marvin E. The Ship's Chronometer. Cincinnati: American Watchmakers Institute Press, 1985.

Date Made: ca 1870

Maker: Wm. Bond & Son

Location: Currently not on view

Place Made: United States: Massachusetts, Boston

See more items in: Work and Industry: Mechanisms, Time and Navigation, Measuring & Mapping


Exhibition Location:

Data Source: National Museum of American History

Id Number: ME.314839Catalog Number: 314839Accession Number: 210897

Object Name: box chronometer

Physical Description: brass (overall material)glass (overall material)steel (overall material)wood (container material)Measurements: overall: 11 in x 10 3/4 in x 11 in; 27.94 cm x 27.305 cm x 27.94 cm

Guid: http://n2t.net/ark:/65665/ng49ca746ab-820c-704b-e053-15f76fa0b4fa

Record Id: nmah_1277030

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