Chronograph
date: label: date made
content: early 1850s
name: label: maker
content: William Bond & Son
notes: label: Description
content: John Locke, a physician and scientist in Cincinnati, realized that, by using an electromagnetic telegraph, an astronomical clock, a circuit-breaking device, and a recording mechanism, he could record the time of an event such as the passage of a star over the meridian. With such a device, moreover, he could compare transit observations made in different observatories, and thus determine the longitudinal difference between the two locations. That was in 1848. Matthew Fontaine Maury, the first Director of the U.S. Naval Observatory, recognized the significance of the invention, and termed it an electromagnetic chronograph.
label: Description
content: William Cranch Bond, the clockmaker who served as the first director of the Harvard College Observatory, took up the challenge of improving the form. Together with his son, George Phillips Bond, he invented a break circuit device (also known as a spring governor or magnetic register). A Bond chronograph of this sort device earned a Council Medal at the Crystal Palace Exhibition held in London in 1851.
label: Description
content: Bond chronographs were installed in several astronomical observatories. This example was made around 1853 for Haverford College, in Haverford, Pennsylvania. An early account reported that, by means of this instrument, “the observer is enabled, by merely touching a spring, to secure a record of the time of the observation to the tenth of a second, without taking his eye from the instrument.”
label: Description
content: Ref: “Haverford School,” <i>Friends’ Review</i> (June 21, 1856): 646-647. Observatory built in 1853, and the Bond Register was expected shortly.
label: Description
content: Ian Bartky, Selling the True Time: Nineteenth Century Time-Keeping in America (Stanford, 2000).
label: Location
content: Currently not on view
place: label: place made
content: United States: Massachusetts, Boston
topic: label: Subject
content: Science & Scientific Instruments
setName: label: See more items in
content: Medicine and Science: Physical Sciences
creditLine: label: Credit Line
content: Haverford College
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1981.0745.09.01
label: catalog number
content: 1981.0745.09.01
label: accession number
content: 1981.0745
objectType: label: Object Name
content: chronograph, drum
physicalDescription: label: Measurements
content: overall: 12 3/8 in x 25 in x 25 in; 31.4325 cm x 63.5 cm x 63.5 cm