Clock by Thomas Tompion, London, ca. 1675.
As the most accurate clock at Harvard in 1761, this one-hundred-year old, "excellent pendulum clock" was taken to Newfoundland by John Winthrop to obser...
Astronomical regulator clock made in London by John Ellicott ca. 1765 to replace similar clock lost in the Harvard Hall fire of 1764.
Brass Heliometer. Made by John & Peter Dollond of London, ca 1758, and shipped to Harvard by Joseph Mico in 1765.
Lecture demonstration of the 1769 transit by Benjamin Martin
Benjamin Martin devised a large demonstration of the appearance of the 1769 transit. The device was 7 by 5? feet in size and mounted on a wall in his shop where he gave lectures. It showed the appeara...
Quadrant engraved "J. Bird, London," ca 1764.
Samuel Dunn's analysis of the 18th-century transits
In his "A Determination of the Exact Moments of Time" (London, 1770), Samuel Dunn provided this large folding plate to compare the appearances of Venus in transit in 1761 and 1769. He also tabulated t...
Samuel Dunn's drawing of Venus in contact with the sun in 1769
A detail from the large plate which appeared in Samuel Dunn's "A Determination of the Exact Moments of Time" (London, 1770). Dunn attempts to record exactly the appearance of Venus when in contact wit...
Reflecting telescope with heliometer engraved "James Short London," ca 1763. Gift of Nathaniel Sparhawk as donor for William Pepperell in 1769.
Equal altitude (transit) instrument by John Bird, London, ca. 1767.
Taken to Newfoundland in 1769 by John Winthrop to observe the transit of Venus.