Who invented logarithm?
The method of logarithms was publicly propounded by John Napier in 1614, in a book titled Mirifici Logarithmorum Canonis Descriptio (Description of the Wonderful Rule of Logarithms).Joost Bürgi constructed a table of powers with a basis very close to 1, and this table provides a fine correspondence between the integers 1-10 (or 10-100, etc.) and exponents that can be added. This table was printed (but perhaps not published) in 1620. However, Bürgi did not define an abstract continuous function as Napier did, and he also did not work out the accuracy of interpolations, which was also tackled by Napier
Johannes Kepler, who used logarithm tables extensively to compile his Ephemeris and therefore dedicated it to Napier,