A tool that served as a calculator in the Middle Ages, today serves as a horror story for children. The logarithm is one of the most famous works, so much so that it is treated as Mirabilis Abreviatio, that is, a semiotically active language. In this post we need concepts of potentiation seen in other topics covered. If you have questions, check the other posts. John Napier - the Baron of Merchiston John Napier - the Baron of Merchiston This work is due to John Napier, the Baron of Merchiston, in his work Mirifici Logarithmorum Canonis Descriptio (1614), which can be translated as A Wonderful Description of the Evolution of the Laws of God. To escape church sanctions, the work was again translated into A wonderful description of the laws of evolution of numbers. Years later Leonhard Euler honored Naiper with the Naperian logarithm. However, the irrational number $e$ was named after Napier, but $e$ comes from Euler.