MONTEREY — Shelby M. Sebring got a taste of what Robert Langdon must have felt like while cracking the Da Vinci Code.
The 15-year-old from Hancock recently unlocked the secrets of a 1759 sermon, while serving as a Young History Scholar intern at the Bidwell House Museum in Monterey.
Sebring, who had just finished her freshman year at Pittsfield High School, loves Colonial history and is an aspiring cryptographer.
As Barbara Palmer, executive director of the museum, explained, interns are encouraged to do a research project of their choosing during their two-week program. When she found out about Sebring’s interests in code, she prompted the intern to take a crack at deciphering some sermons written by the enigmatic Rev. Adonijah Bidwell, the museum’s namesake.
‘‘I've always wanted to be a docent. I love history,’’ said Sebring.
Raised in a military family, Sebring has moved a lot and visited historical sites while on the road. ‘‘Some people go to Six Flags for vacation; we go to Williamsburg,’’ Sebring said.
But for two weeks in June, she immersed herself in a paid internship program at the Bidwell House Museum.
There Sebring learned that Bidwell served as the first minister in ‘‘Housatonic Township No. 1,’’ today’s Tyringham and Monterey.
In the 18th-century parsonage, Bidwell wrote his sermons in a private code: a mixture of early forms of English, Greek, Latin, symbols, and shorthand.
‘‘Not much is known about the reverend,’’ Palmer said. “The only writings we have here are sermons, all written in code.”
‘‘Most are in plain English, but there is shorthand and symbols like this,’’ said Sebring, pointing to a mark on a photocopy of an original page. ‘‘See? This looks like a snail.’’
Palmer said that over decades, many people have taken a look at Bidwell’s sermon texts, ‘‘but to my knowledge, no one has been able to — or taken the time necessary to — crack Bidwell’s code.’’
Sebring started her work with a Christmas gift, a book titled, ‘‘Codes, Ciphers and Other Cryptic and Clandestine Communication: 400 Ways to Send Secret Messages from Hieroglyphs to the Internet’’ by Fred B. Wrixon.
She also used an online guide to 18th-century shorthand and penmanship, biblical references, and ‘‘common sense’’ to chart the four-page sermon, titled ‘‘Proud.’’ It is labeled with three dates: 1759, 1761, and 1783.
Sebring filled three notebooks, first by writing down all the recognizable English, then mapping the numbers and symbols, and then trying to substitute words for the symbols in a way that made sense.
‘‘There was a lot of guess and check,’’ Sebring said, noting that she has no background in Greek, Latin, middle English, or the Bible.
Eventually, she figured that the numbers in the sermon referred to Bible verses. Ultimately, Sebring revealed an eight-page typed sermon about why people should be wary of exhibiting pride.
Sebring worked day and night, and beyond the scope of her two-week internship, to crack Bidwell’s code.
Palmer called the student’s effort a combination of ‘‘great passion’’ and ‘‘diligence.’’ She also lauded the contributions of the museum’s other interns, seven from high school and one from college, this summer.
‘‘They’ve all added value here,’’ said Palmer.