This is a page from Gustavademecum for the Island of Manhattan: A Check-List of the Best-Recommended or Most Interesting Eating-Places, Arranged in Approximate Order of Increasing Latitude and Longitude — Prepared for the convenience of mathematicians, experimental scientists, engineers, and explorers. Which is possibly the best name for a dining guide ever.
Physical chemist Robert Browning Sosman passed this pocket-sized guidebook out at conferences and updated it regularly between 1941 and 1962.
The key feature: Sosman's ... somewhat unique ... observations about the restaurants he visited. And the fact that much of that information was encoded in a sort of proprietary shorthand, cribbed from scientific symbols. The result looks something like a cross between restaurant listings and an alchemist's workbook.
In each of the guide's at least 15 editions, Sosman reviewed 300 restaurants, relaying facts like cuisine and cost, as well as esoteric observations like tableside lighting (measured in lumens) and waiters' estimated IQs. All of it was written in a mashup of mathematical figures, glyphs, Greek, and astrological symbols. A sigma meant there was samba dancing. A lowercase "m" suggested that Madison Avenue types frequented the restaurant
Sadly, the Saveur.com story that this comes from doesn't include a cheat sheet guide to deciphering Sosman's shorthand. A major disappointment. Perhaps one of you can add to the information here?