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COLLECTION Identifier: UAV 630.349

Records of the Harvard College Observatory Chronometric Expedition


In the mid-nineteenth century, the Chronometric Expedition was carried out by the Harvard College Observatory, under the direction of William Cranch Bond and in conjunction with the United States Coast Survey. The expedition used chronometers that were made by William Bond & Son, the Bond family's private business, to determine differences of longitude between the observatories in Cambridge, Massachusetts and Liverpool, England. The records primarily consist of notebooks, data sheets, reports, and correspondence documenting the Observatory’s expeditions to England in 1849, 1850, 1851, and 1855, and give insight into the scientific and logistical planning and execution of the chronometric expeditions, the results of which established more accurate longitudinal measurements for the entire United States.


  • 1845-1875


Language of Materials


Conditions Governing Access

The records are open for research.


7.88 cubic feet (19 flat boxes, 3 letter document boxes, 1 half-document letter box, 1 legal document box)
The Harvard College Observatory Chronometric Expedition Records primarily consist of notebooks, data sheets, reports and memoranda, and correspondence, which document the Observatory’s expeditions to England to determine differences of longitude between the observatories in Cambridge, Massachusetts and Liverpool, England in 1849, 1850, 1851, and 1855. The records contain hundreds of data sheets that capture rates and comparisons of chronometers in Cambridge, Massachusetts and Liverpool and Greenwich, England; rates of time and temperature; and recordings related to stars. Many of the data sheets are on official United States Coast Survey stationery forms. The vast number of sheets and calculations demonstrate the complexity involved in determining longitude. The records give insight into the scientific and logistical planning and execution of the chronometric expeditions, the results of which established more accurate longitudinal measurements for the entire United States.

The correspondence includes many letters between Observatory director William Cranch Bond and U.S. Coast Survey superintendent A.D. Bache. The letters discuss equipment needs, budgets, and give descriptions of the expeditions’ progressions. Bond also wrote to several notable figures about the logistics and results of the expeditions, including to United States Consul to England Nathaniel Hawthorne, scientist Philip Sidney Coolidge, and Bond's son, Richard F. Bond. The letters provide insight into the planning and execution of the surveys, as well as the ensuing publication of the scientific results. The notebooks primarily contain chronometric comparison calculations from Cambridge, Liverpool, and Greenwich; some notebooks also include longitudinal and temperature comparisons, and U.S. Coast Survey planning notes. The records also include some memoranda related to the planning of the expeditions, reports of the results, and materials related to the expeditions’ publications.

Historical note on the Chronometric Expedition

In the mid-nineteenth century, the Chronometric Expedition was carried out by the Harvard College Observatory in conjunction with the United States Coast Survey. Its mission was to determine differences of longitude between the observatories in Liverpool, England and Cambridge, Massachusetts. In 1849, Alexander Dallas Bache, superintendent of the U.S. Coast Survey, gave Observatory director William C. Bond formal survey sponsorship and funding to transport groups of chronometers back and forth from Massachusetts to England. The work was conducted in 1849, 1850, 1851, and 1855. As a result of these calculations, the longitudes of all principal observatory positions within the United States were dependent upon the longitude of Harvard University; in 1859, Bond wrote to Harvard president Edward Everett, "Cambridge is now the central geographical point of this Continent...Our longitude has, undoubtedly, been investigated with more care than that of any other spot on the globe."
Historical note on the Harvard College Observatory In 1839, the Harvard Corporation appointed William Cranch Bond the first Astronomical Observer to the University, thereby taking the first step in establishing the Harvard College Observatory, after which the first telescope was installed in 1847. Scholars and students had studied astronomy at Harvard since the seventeenth century, but it wasn’t until a large comet sparked public interest in 1843 that donors began donating funds to build an observatory. During the tenure of the Harvard College Observatory’s first three directors, William Cranch Bond (1839-1859), George Phillips Bond (1859-1865), and Joseph Winlock (1866-1875), much of the Observatory’s research focused on lunar photography and chronometric activities to establish American longitude and to operate a time service for the United States government and commercial interests. In the late nineteenth century and early twentieth century, under the direction of Edward C. Pickering (1877-1919), research shifted from celestial mechanics and positional astronomy to astrophysics. The Observatory developed into a major research institution, focusing on photographic star surveys, spectroscopic analysis, and culminating in publication of the Henry Draper Catalogue, with spectroscopic classifications for 225,300 stars. During Pickering’s tenure, many women astronomers, including Annie Jump Cannon, Henrietta Swan Leavitt, Cecilia Payne-Gaposchkin, and Williamina Fleming performed essential research at the Observatory.

During the next several years, the Observatory became an important center for astronomical training and research, and building relationships with other institutions. Harlow Shapley, director from 1921 to 1952, inaugurated a program of graduate study in astronomy. Mandating that public education be a part of the Observatory’s mission, Shapley required students in the Harvard program to present lectures on astronomy to public school children. Donald H. Menzel (1952-1966) arranged a cooperative relationship with the Smithsonian Astrophysical Observatory (founded in 1890) and its relocation to Cambridge in 1955. Financial support for the Observatory expanded under Leo Goldberg (1966-1970), and in 1973 George B. Field (1972-1983) created an administrative umbrella organization, the Harvard-Smithsonian Center for Astrophysics, to coordinate the Smithsonian Astrophysical Observatory and the Harvard College Observatory’s programs. Today, the Harvard-Smithsonian Center for Astrophysics continues studies in astronomy, astrophysics, earth and space sciences, and science education, while the Harvard College Observatory supports Harvard’s Department of Astronomy.
Biographical note on William Cranch Bond William Cranch Bond (1789-1859), American astronomer and instrument maker, was the first director of the Harvard College Observatory from 1839 to 1859.

Bond’s father William (died 1848) was a clockmaker and established William Bond & Son. The firm made scientific instruments, particularly chronometers. In 1804, from directions he found in an old French textbook, Bond made his first chronometer. Bond continued his work improving chronometers so that by 1812, they were regularly used on Boston merchant ships. After viewing a total eclipse of the sun in 1806, Bond became fascinated with astronomy. Between 1825 and 1830, he increasingly improved the accuracy of his chronometers, and in 1838, he received a contract from the United States Navy to make longitudinal and other measurements during its exploratory expeditions from 1838 to 1842.

The establishment of an observatory at Harvard University was fostered by astronomical discoveries taking place in the late eighteenth and early nineteenth centuries. The plans for the observatory remained dormant until 1839, when Harvard president Josiah Quincy persuaded Bond to move his astronomical instruments to Dana House and become the first Astronomical Observer to Harvard University. Working without pay for the next five years, Bond remained at Dana House making what were in large part meteorological and magnetic observations. However, using the limited equipment available, Bond also observed occultations, eclipses, and comets; in addition to continuing his work as a clockmaker; and carrying out his duties to the United States Navy. Bond also began planning the construction of a new Harvard observatory and the addition of new equipment. After Bond died in 1859, his son George Phillips Bond succeeded him as director of the Harvard College Observatory.
Biographical note on Richard Fifield Bond Richard Fifield Bond (1827-1866), clockmaker, was born in Dorchester, Massachusetts. Like his elder brother, George, Richard was a partner in the family clock-making business, William Bond & Son. He sailed to Liverpool, England, with the United States Coast Survey Chronometric Expedition in 1855. Richard married Sarah (Sally) Apthorp Cunningham Clinch (1835-1914), and they had one son, William Cranch (born 1860), who eventually joined the family business, and two daughters, Edith (1862-1878) and Mary (1863-1894).
Historical note on Wiliam Bond & Son William Bond & Son was established in Boston, Massachusetts, in 1793 by William Bond, Sr.(1754-1848), an English silversmith and watchmaker. His son, the astronomer William Cranch Bond (1789-1859), joined him in the business, which later expanded to include his sons, Joseph Cranch Bond (1823-1860) and Richard Fifield Bond (1827-1866) as partners. The firm manufactured, imported, and repaired clocks, watches, and chronometers. William Cranch Bond constructed the first American-made marine chronometer, and the business supplied and repaired chronometers for the United States government, which were used in surveys of the Atlantic Coast and the Colorado River. William Cranch Bond and his son, George Phillips Bond, also devised a break circuit device that attached to the escapement of a clock, which became the foundation of the new "American method" of determining longitude. The device, which they termed a "spring governor," earned a Council Medal at the London Crystal Palace Exhibition of 1851.


The records are arranged in five series:
  1. Computations and data sheets, 1848-1875 and undated
  2. Correspondence and notes, 1849-1856
  3. Notebooks, 1849-1855
  4. Reports, data, and memoranda, 1845-1855 and undated
  5. United States Coast Survey Chronometric Expedition data sheets, 1849-1855 and undated

Related Materials

In the Harvard University Archives
  1. William Cranch Bond family collection, 1845-1872 and undated (HUG 1225 and HUG 1226).
  2. Records of the Harvard College Observatory Director George Phillips Bond, 1851-1865 (UAV 630.6).
  3. Papers of George Phillips Bond, 1851-1865 (HUG 1224.803 and HUG 1224.805).
  4. Records of the Harvard College Observatory Director William Cranch Bond, 1818-1819, 1840-1864 (UAV 630.2).
In Houghton Library
  1. William Cranch Bond Correspondence, 1840-1852 (MS Am 2805)
In the Collection of Historical Scientific Instruments, Harvard University
  1. William Bond & Son records and Bond family papers, 1724-1931 (inclusive), 1769-1923 (bulk) (hsi00001)
  2. The Collection of Historical Scientific Instruments holds numerous instruments used by William Cranch Bond including astronomical regulators, chronometers, casting patterns, and clocks.


  • Holden, Edward Singleton and Mrs. Richard F. Bond. Memorials of William Cranch Bond: Director of the Harvard College Observatory, 1840-1859, and of His Son George Phillips Bond, Director ... 1859-1865. San Francisco: C.A. Murdock & Company, 1897.

Inventory update

This document last updated 2020 February 20.

Processing Information

This finding aid was created by Olivia Mandica-Hart in May-July 2018. Processing included rehousing materials in the appropriate containers, establishing a series hierarchy, and creating this finding aid. Titles were devised by the archivist.
Link to catalog
Harvard College Observatory. Records of the Harvard College Observatory Chronometric Expedition, 1845-1875: an inventory
Harvard University Archives
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Describing Archives: A Content Standard

Repository Details

Part of the Harvard University Archives Repository

Holding nearly four centuries of materials, the Harvard University Archives is the principal repository for the institutional records of Harvard University and the personal archives of Harvard faculty, as well as collections related to students, alumni, Harvard-affiliates and other associated topics. The collections document the intellectual, cultural, administrative and social life of Harvard and the influence of the University as it emerged across the globe.

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