Logarithm table. Historical table of logarithms. Logarithms are mathematical functions relating numbers to the powers of a set base number such as ten. The other common base used is of the natural number e, used to describe many exponential or logarithmic processes in nature. John Napier discovered these natural logarithms and published the first logarithm, or log, tables in 1614. These were used to aid calculations, as computing the values of logarithms was a time-consuming process. The use of log tables has been superseded by the use of electronic calculators. The table is from a book published in 1815.