Who discovered logarithm?
The logarithms appeared many time in the history of Maths, but were never studied properly until the XVII century.
The scottish astronomer, physicist and mathematician John Napier published the first work on logarithms: the book "Mirifici Logarithmorum Canonis Descriptio" written in 1614.
That's why the constant
The swiss astronomer, clockmaker and mathematician Joost Bürgi discovered indipendently the logarithm even earlier than Napier but he was convinced by Kepler to publish his work on logarithms only in 1620.
The logarithms were mostly used by astronomers because of the hard calculations they had to do. Henry Briggs wrote the first logarithm table in 1620.
However, the modern definition of logarithm comes from the studies of Euler of 1730.