Jacques Inaudi had a great brain–more than one, in a sense.

He was what was known more than a century ago as a “Lightning Calculator,” a sideshow performer who solved complicated mathematical problems in his head in front of live audiences. Few had the facility for numbers displayed by Inaudi, an Italian who toured extensively with vaudeville shows demonstrating his prodigious abilities. The Brooklyn Daily Eagle profiled the math man on October 15, 1901 (and misidentified his nationality). An excerpt: