Title page of a book of logarithmic tables by Vlacq, 1670.
© Science Museum / Science & Society Picture Library
Adrian Vlacq's logarithmic tables, first published in 1628, formed the basis of tables for many years, due to their relative lack of errors. This French edition is one of the selection of tables collected by the British mathematician and computing pioneer Charles Babbage (1791-1871). His private collection preserved at the Royal Observatory at Edinburgh contained over 300 volumes. He was a fastidious analyst of tabular error. Mathematical tables were an aid to those profesions which required the performing of calculations demanding more than a few figures of accuracy. Logarithms made the manipulation of large calculations simpler by adding or subtracting the index of two numbers and looking up the result in tables.