Benjamin Franklin's Numbers: An Unsung Mathematical Odyssey

Pasles, an associate professor of mathematics at Villanova, speculates gleefully on the oft-denied mathematical genius of Benjamin Franklin. The author focuses on magic squares, a type of matrix that Franklin dismissed (inaccurately) as “incapable of any useful application” but enjoyed playing with for almost 50 years. Not content with matrices where columns, rows and diagonals all have equal sums, Franklin created magic squares where bent diagonals and other groupings have special properties and then went on to develop even more complex magic circles, outclassing not only his contemporaries but also many modern mathematicians Drawing on Franklin's letters and journals as well as modern-day reconstructions of his library, Pasles touches on Franklin's fondness for magazines of mathematical diversions; publication of arithmetic problems in Poor Richard's Almanac ; startlingly accurate projections of population growth and cost-benefit arguments against slavery. Going further afield, he suggests that only a man comfortable with numbers would refer to electrical poles as “positive” and “negative” and wonders what might have transpired had a young Franklin been introduced to Isaac Newton by a mutual acquaintance. Historians may quail at the textbook-style problems that illustrate various topics, but mathematicians will enjoy them and share Pasles's pleasure at restoring Franklin's tarnished numerological reputation. Color and b&w illus. (Nov.)