Jefferson's Conundrum Mystery Cache

Laurel Hill Cemetery, in Philadelphia, PA, is one of the few cemeteries in the United States designated as a National Historic Landmark.  It is the second major cemetery in the country built as a rural cemetery or garden cemetery, which is a style of burial ground that uses landscaping in a park-like setting.^[2] John Jay Smith, a librarian and editor with interests in horticulture and real estate who was distressed at the way his deceased daughter was interred in a Philadelphia churchyard, founded Laurel Hill in 1836. He and some other prominent citizens decided to create a rural garden cemetery five miles north of Philadelphia that was viewed, at the time, as a haven from urban expansion and a respite from the increasingly industrialized city center. The city later grew past Laurel Hill, but the cemetery retained its rural character. ^[1]

Famous Revolutionary War figures were initially relocated to Laurel Hill Cemetery to increase its cachet, including Continental Congress secretary Charles Thomson; Declaration of Independence signer Thomas McKean; Philadelphia war veteran and shipbuilder Jehu Eyre; Hugh Mercer, hero of the Battle of Princeton; and David Rittenhouse, first director of the U.S. Mint. During and after the American Civil War, Laurel Hill became the final resting place of hundreds of military figures including 42 Civil War era generals. Laurel Hill also became the favored burial place for many of Philadelphia's most prominent political and business figures, including Matthias W. Baldwin, founder of the Baldwin Locomotive Works; Henry Disston, owner of the largest saw manufactory in the world (the Disston Saw Works), and Peter A. B. Widener, the financier. ^[1]

Among those interred in the Laurel Hill Cemetery is Robert Patterson (May 20, 1743 – July 22, 1824). He was an American educator and director of the United States Mint. He was born on a lease-held farm near Hillsborough, County Down, Ireland, emigrated to the United States in 1768, and lived for a time in Philadelphia. ^[3]

From 1779 to 1814, he was professor of mathematics in the University of Pennsylvania, being also from from 1810 to 1813 vice provost. In 1805, without solicitation, President Jefferson appointed him director of the mint, which position he held until a short time before his death. Always actively interested in the American Philosophical Society, he was its president from 1819 until his death.  ^[3]

On Christmas Day 1801, Thomas Jefferson received a letter from Robert Patterson describing a perfect cipher and then giving an example of its use.  Patterson began by describing four requirements of what he called a “perfect cypher.” It should work in any language, be easy to memorize, and be simple to perform. Most important, an ideal cipher should be “absolutely inscrutable to all unacquainted with the particular key or secret for decyphering.” Patterson described a technique that met his criteria, and gave an example. “I shall conclude this paper with a specimen of such writing,” he boasted, “which I may safely defy the united ingenuity of the whole human race to decypher to the end of time….” Indeed, by all accounts, neither Jefferson nor anyone else could break Patterson’s challenge cipher for the next two centuries. ^[4]

This cipher remained unsolved until 2007 when Lawren Smithline, a mathematician at the Center for Communications Research,Princeton, New Jersey decoded the message. ^{[4] [5]}

A cipher that was so effective that it was not solved for two hundred years should be a natural challenge for a puzzle cache. The directions for finding the cache are encoded using Patterson's cipher on this old bit of parchment we found recently.

(For larger image, save image and view in your favorite drawing program)

To decode the cipher,  you will need to know how the cipher works and the keys used in the cipher. You can learn about the cipher from the Internet with the right search parameters. The keys to the cipher are scattered in plain sight in the Laurel Hill Cemetery.  Each key will consist of a two digit number, neither of which will be a zero. The keys will be revealed in their proper order if you correctly answer the following set of questions.

It is suggested that you first visit the monument for Robert Patterson and pay your respects. It happens to be a white obelisk at the posted coordinates.  There you will find one of the cipher keys.  Then you will need to take the audio tour of the cemetery which starts at the office at the cemetery gate house.  If you listen attentively to the audio tour and use your well honed powers of observation, you will be able find the rest of the cipher keys.  You will need a cell phone and there is no charge for the audio tour other than what your cell phone provider may charge you for the minutes that you use.

Please note that Laurel Hill Cemetery is open Monday to Friday from 8:00 AM to 4:30 PM and Saturday and Sunday from 9:30 Am to 5:00 PM.  The cemetery welcomes visitors during those times to explore the grounds.  It is very important to note that the keys to the cipher are in plain site.  There are no objects hidden in the cemetery other than the final cache.  Please remain respectful of the departed while touring the cemetery and there is no need to disturb any objects or features in the cemetery.  The keys are in the open and in plain sight, they are not hidden. Just read the questions and listen closely to the audio tour and look sharp to find the keys.

Acknowlegements

We would like to thank the Laurel Hill Cemetery for allowing us to place this cache in their grounds. Also our appreciation goes to Math Teacher and Y's Owl' for pointing out the interesting article in the Wall Street Journal that lead us to this cipher.  Acknowledgement is also given to the Wall Street Journal, Harvard Magazine and Wikipedia for historical information that quoted and paraphrased in the text of this listing.  Finally Y's Owl's help in the field work at the Laurel Hill Cemetery was invaluable.

Notess

1. Wikipedia article - Laurel Hill Cemetery
2. Wikipedia article - Rural Cemetery
3. Wikepedia article - Robert Patterson
4. Harvard Magazine article - Jefferson's Conundrum
5. Wall Street Journal article - Two Centuries On, a Cryptologist Cracks a Presidential Code