Robert Browning Sosman, a physical chemist who died in 1967 at the age of 86, packed many careers into one lifetime. He wrote the definitive book on the chemical compound silica; was the seventh person to hike the entire Appalachian Trail; and, at home in New Jersey, kept a 3,500-strong map collection. He also made a significant contribution to the New York dining scene: Between 1941 and 1962, while frequenting Manhattan for work, Sosman compiled notes for his self-published 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. An unusual but visionary restaurant guide "for the convenience of mathematicians, experimental scientists, engineers, and explorers," it crammed a gastronomic brain trust into a 16-page, saddle-stitched leaflet filled with hand-drawn symbols.
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; Don Drapers of the day might be found slurping bouillabaisse at Le Provençal.
The guide is now 50 years out of print—a single copy is tucked away in a geological texts cabinet at Yale—but in its time, it was a favorite of the slide rule crowd, who received copies when Sosman distributed them at conferences.
"It fit nicely in the inside pocket of our suit coats," said George Fischer, whose boss at a firm that made type-reading machines for credit card receipts gave him a guide in 1958. The Gustavademecum (gustare is Latin for "to taste manual") transformed rote business meals into adventures. Deciphering Sosman's algebra, says Fischer, was "part of the fun."