MoonFigureThe start of a new month (rainy and cold here in Philadelphia) has reminded me to write about a new almanac fragment here at Penn. In November of last year, the Penn Libraries purchased a unique and somewhat mysterious eighteenth century manuscript. Consisting of a single bifolium (a sheet folded to make four pages) it was likely produced in Philadelphia (or somewhere else of a similar latitude) in 1746/7. It appears to be part of an almanac containing eclipse charts, predictions for weather, and astrological signs, removed from what must once have been a larger manuscript volume. Astronomical and almanac manuscripts from colonial Philadelphia are not common though there was a robust trade in print almanacs and lunar charts throughout the city in the period with at least four different almanacs each year by mid-century [1].

What initially drew my attention to the manuscript was its attribution to David Rittenhouse, the famous Philadelphia astronomer, inventor, and treasurer of the Continental Congress. His masterful 1771 Orrery is today here in the University of Pennsylvania Libraries. To be clear, the attribution of this manuscript to Rittenhouse is decidedly uncertain. There is a small pencil annotation of unknown date on the side of the bifolium listing him as the author.


Arguing against the attribution is the fact that the manuscript contains the lunar tables and almanac for 1747 indicating likely creation in 1746 when Rittenhouse would have been only 14 or 15 years old. The only substantial collection of Rittenhouse astronomical manuscripts is at the American Philosophical Society which holds three of his notebooks from the last quarter of the century. A look at the handwriting in these neither convinced me nor completely dissuaded me from the attribution. That Rittenhouse could have composed or copied a set of lunar tables and almanac as a teenager is not necessarily as far-fetched as it seems. Later reports of his early years noted that at the age of 14 many of the fences and plows with which he worked were covered with notations and mathematical formulas, by the age of 17 he had even constructed a fully functional clock by himself [2].

1747RittenhouseAnother, somewhat more likely possibility is that the manuscript is a copy or partial copy of a printed almanac circulating in the period. The chart for the month of January, for instance, is very reminiscent of the print almanacs of the time – beginning with an aphorism or epitaph followed by a series of predictions and notes about the days of the month. Given this,  I think it likely that at least part of the text was copied by a young Rittenhouse (or someone else) from a printed almanac.

There were at least four or five different almanacs printed each year in Philadelphia with more in New York and Boston. What’s interesting and remarkable is that the text in the manuscript does not match any of these surviving American almanacs for 1747 that I have been able to locate. Of the almanacs likely to have printed in Philadelphia for that year, only one has failed to survive in any copies, the Franklin-published 1747 American Country Almanac which has never been traced [3]. From the description of the New York issue of the American Country Almanac for that year which survives in one copy at the Huntington, it seems unlikely that this is a copy of that particular text [4].

1747 Poor Richard's Almanac. Curtis

January, from Poor Richard’s Almanac for 1747. Printed by Franklin. UPenn Curtis 345.


January, from the Philadelphia issue of the American Country Almanac for 1748. HSP copy (Evans Digital)


January, from the Philadelphia Pocket Almanac for 1747. Printed by Franklin. UPenn Curtis 161.

One of the pleasures of working in libraries is acquiring manuscripts like this one, about which much remains unknown. I hope that this post generates interest in the manuscript and inspires a student or researcher to take a closer look and delve into its origins and what it might be able to tell us about astronomical commonplacing and almanac creation in colonial America.


For two recent excellent pieces on the place of Almanacs in the early American world see, Patrick Spero, “The Revolution in Popular Publications: The Almanac and New England Primer, 1750—1800” Early American Studies, Vol. 8, No. 1 (Winter 2010), pp. 41-74 and Matthew Shaw, “Keeping Time in the Age of Franklin: Almanacs and the Atlantic World,” Printing History 2 (2007).

See the Memoirs of the Life of David Rittenhouse (Philadelphia, 1813), p. 96.

In his survey of Franklin’s printing, Benjamin Franklin’s Philadelphia printing, 1728-1766 (Philadelphia, 1974) [no. 392] Clarence Miller lists this as possible but doubtful based on the fact that though Franklin-issued copies of the American Country Almanac survive for 1746 and 1748, he did not advertise one for 1747 and the New York copy at the Huntington does not have Franklin’s tell-tale anatomical woodcut.

With many thanks to Vanessa Wilkie and Steve Tabor at the Huntington for their help with this.