☞ Poor Richard improved : being an almanack and ephemeris ... for the year of our Lord 1775 ... fitted to the latitude of forty degrees, and a meridian of near five hours west from London; but may, without sensible error, serve all the northern colonies : by Richard Saunders, philom.
This series is apparently an extension of Benjamin Franklin's Poor Richard's almanack, published from 1732 to 1758, though the catalog record does not attribute the text to him. 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. Bibliographers attribute the astronomical calculations contained in the 1775, 1779, and 1781 installments to Rittenhouse, but he likely contributed to others.
APS has two copies (copy one; copy two) of the 1775 installment and one copy of the 1779 installment, plus numerous installments whose astronomical calculations are not attributed to Rittenhouse.