The number e, the base of the natural logarithm, has been known to exist for many years. The constant e was discovered by the Swiss mathematician Jacob Bernoulli while studying compound interest. It is named e to honor Leonard Euler. The first references to the constant were published in 1618 in the table of an appendix of a work on logarithms by John Napier. John Napier did not actually define the constant, but he used it. The discovery of the constant itself is credited to Jacob Bernoulli in 1683, who attempted to find the value of the following expression (which is equal to e):
limit as n approaches infinity of (1 + 1/n)n.