☞ A pocket almanack for the year 1775 : fitted to the use of Pennsylvania, and the neighbouring provinces : with several useful additions : by R. Saunders, phil.
Although the catalog record does not attribute this text to Benjamin Franklin, he published an almanac under this title between 1741 and 1783 and used the name "R. [i.e., Richard] Saunders" in his Poor Richard's Almanac. The same set of astronomical calculations appear in several almanacs published in Pennsylvania in this period. Many bibliographers attribute them all to Rittenhouse based on the explicit attribution to him of the calculations found in certain almanacs, but others dispute this. This is the only installment that bibliographers attribute to Rittenhouse, but he likely contributed to others.
APS has a copy of at least one installment but does not have copies of the installments whose astronomical calculations are credited to Rittenhouse.