David Rittenhouse built this telescope and clock to track the movement of stars and planets during the transit of Venus in 1769.

In 1769, the path of Venus traveled between the earth and the sun, creating a planetary eclipse, or transit. Rittenhouse participated in an international effort to record the duration of the transit from locations around the world. These notations would be used to calculate the distance from Earth to the Sun. Rittenhouse’s participation in this world-wide collaboration helped counter the belief that America was intellectually inferior to Europe.