FOR MANY ENLIGHTENMENT figures, time was less a phenomenon than a predicament. Never had its role in physics been better understood, nor its passage measured more accurately. But the more tangible it seemed, the more elusive it became. Despite the introduction of the Gregorian calendar in 1582, Catholics were still not sure when they should celebrate certain festivals. Major questions of world history were unresolved. And political upheavals had left many rulers out of step with the times.
If anyone could put things right, it was Francesco Bianchini (1662-1729). As John Heilbron points out in this biography, contemporaries regarded him as the greatest Italian of his day. According to a Roman epigram, there was nothing he could not understand — and everything seemed
