During the years of 1767-1770 David Rittenhouse designed and produced two orreries, one for Princeton Univ. and one for the Univ. of PA. During the last two years of this interval he also produced two... Read More
During the years of 1767-1770 David Rittenhouse designed and produced two orreries, one for Princeton Univ. and one for the Univ. of PA. During the last two years of this interval he also produced two... Read More