Figure 6. — Astronomical clock made by David Rittenhouse 

 for his observatory at Norristown,Pa.,and used by him for the 

 observation of the transit of Venus in 1769. Unembellished 

 pine case 83>^ in. high, 13J.1 in. wide at the waist with a 

 silvered brass dial 10^^ in. diameter. Photo courtesy the 

 American Philosophical Society. 



Figure 7. — Orrery built by David Rittenhouse for the Uni- 

 versity of Pennsylvania. The center section shows the 

 motions of the planets and their satellites and the right- 

 hand section the eclipses of the Sun and Moon. The case, 

 considered to be an outstanding example of colonial cabinet- 

 work, was make by John Folwell. 



Figure 8. — Brass surveying compass inscribed "Made by 

 Benjamin Rittenhouse, 1787." Photo courtesy Ohio State 

 Museum, Columbus, Ohio. 



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