April 4th , 1617
john Napier of Merchiston (1 February 1550 – 4 April 1617), nicknamed Marvellous Merchiston, was a Scottish landowner known as a mathematician, physicist, and astronomer. He was the 8th Laird of Merchiston. His Latinized name was Ioannes Neper.
John Napier is best known as the discoverer of logarithms. He also invented the so-called “Napier’s bones” and made common the use of the decimal point in arithmetic and mathematics.
Napier’s birthplace, Merchiston Tower in Edinburgh, is now part of the facilities of Edinburgh Napier University. There is a memorial to him at St Cuthbert’s at the west side of Edinburgh.