Mercator, Nicolaus (c. 1620–1687)

Danish mathematician. In 1668 he published Logarithmotechnia, the first book to expound the theory of logarithms in the modern form. Isaac Newton wrote his ‘De analysi per oequationes infinitas’ setting out his general method for obtaining expressions of functions as infinite series in response to Mercator's work.

Kauffman was born in Schleswig-Holstein (now part of Germany) and was educated at the University of Rostock, then taught at the University of Copenhagen and published textbooks on trigonometry. He settled in England about 1657, became a mathematics tutor, befriended the mathematicians William Collins and William Oughtred, and adopted the Latin form of his name. He was elected a Fellow of the Royal Society in 1666 in recognition of his work on a marine chronometer.