The last time the Internet argued about a dress, we ended up paranoid and doubting our own eyes. However, this time the story is much more satisfying: an irresistible Victorian piece in a shop, strange messages inside it, cryptography enthusiasts trying to uncover its meaning, and the correct answer after a decade of mystery… or should I say 140 years?
The story begins during the Christmas season of 2013, when archaeologist and collector Sara Rivers Cofield visited an antique shop in Maine. There she found a Victorian silk dress, which she temporarily dated to the 1880s. Sara explains on her personal blog that she doesn't usually buy silk because it tends to be worth a fortune and requires a lot of maintenance (even in storage), but that time she decided to make an exception.
The value of the original buttons was more than enough to cover the investment and make a profit, but Sara doesn't sell anything from her collection... and she also found three very special items: a label with a name (“Bennett”), a pin in the bustle… and two pieces of paper hidden in an inside pocket, with incomprehensible phrases.
Deciphering the "Silk Dress Cryptogram"
Bismark, omit, leafage, buck, bank
Calgary, Cuba, unguard, confute, duck, fagan
Spring, wilderness, lining, one, reading, novice
These are just a few examples. Many of the words are repeated, and there are also numbers between the lines, along with three times in the margin (10pm, 11:13pm, and 11:24pm). Sara decided not to follow the path of the messages, and essentially posted them on the Web for anyone interested to try to decipher them.
The first theories didn't take long to appear: an encrypted love letter, dress measurements, Civil War codes. Sara ruled out a connection to the Civil War because she studied catalogs published in the 1880s, and the dress definitely belongs to that era (at minimum, the war had ended fifteen years earlier).
Finally, Wayne Chan, a researcher at the University of Manitoba in Canada, came across the code in mid-2018. Chan solves codes as a hobby, and compared the data with more than 170 cryptographic books, but nothing came of it. Chan analyzed the messages for a few months, set the project aside, and came back with a different strategy, studying everything he could find about 19th-century telegraphy.
The first clue was in a passage from the book "Telegraphic Tales and Telegraphic History" by William Johnston, which describes the report of a station in New York: "York, Monday, Dead, Fire, Grind, Himself, Ill, Ovation, View". That station belonged to the weather observation network developed by the U.S. Army Signal Service (now the Signal Corps). In other words, that service was the "Weather.com" of the country for over two decades, later moving to civilian control.
So yes, the strange phrases were weather reports. Why the code? Simple: Sending an entire report by telegram was extremely expensive, since charges were applied per word. The solution was to create a code capable of compressing a large amount of information into a few words, without causing interpretation errors. Chan had trouble obtaining the books with the codes, but after combining data from the "Signal Service Meteorological Code" of July, old maps digitized by the central library of the NOAA, reports kept by the Purdue University Regional Climate Center, and data from Canadian stations, he arrived at a precise date: May 27. To finish, here is the exact meaning of one of the codes.
BISMARK, Bismarck station, Dakota Territory (now North Dakota)
OMIT, air temperature 56F, pressure 0.08 Hg (only the decimals, the base could change depending on the station location, in this case it was 30.08)
LEAFAGE, dew point 32F, observation time, 10:00 p.m.
BUCK, clear, no precipitation, north wind
BANK, wind speed, 12 miles per hour, clear sunset
Sources: Sara Rivers Cofield's blog, NOAA, University of Manitoba, CNN
