John Napier was a famous Scottish mathematician who is best known for his invention of logarithms which are used to help with mathematical calculations.

He is also credited with bringing the decimal point into common use.

### Early Life and Education:

John Napier was born into a wealthy family on February 1 in 1550 in Edinburgh, Scotland. His father was Sir Archibald Napier. He was a very intelligent child and was admitted in the University of St. Andrews when he was thirteen years old in 1563. While at university, he lived in St Salvator’s College and the Principal of the University, John Rutherford took personal care of him.

While he was at St Andrews he became interested in theology, an interest that was to remain with him for the rest of his life.

There is no record of John graduating and it is most likely, as was the custom at the time, that Napier also travelled abroad and studied at universities in France and Italy.

Napier returned to his homeland by 1571 and married Elizabeth Stirling in 1573. The couple had two children together. Now in his twenties, his father’s estates were made over to him and a castle was built at his estate at Gartness in 1574.

At the castle of Gartness, Napier took an interest in the running of the land had also time to explore his interests in the field of religious politics, agriculture and mathematics.

### Contributions and Achievements:

Napier was an ardent Protestant and he published “A Plaine Discovery of the Whole Revelation of St. John” in 1594 based partly on concerns that Philip of Spain might invade Scotland. The work occupies a prominent place in Scottish ecclesiastical history.

Napier also invented four new kinds of weapons in case there was a war with Catholic Spain. The weapons included an artillery piece, a type of battle vehicle, driven by men inside, covered with plates of metal which had a tiny opening for emitting odious smoke and firepower and two kinds of mirrors for setting fire to enemy ships.

In mathematics, he made remarkable discoveries that were accurate and were accepted all over the world. It is believed that he began working on his logarithms from 1594. His technique of calculation of log was published in 1614 “Mirifici logarithmorum Canonis Descriptio” (A Description of the Wonderful Table of Logarithms).

His book contained fifty-seven pages of explanatory matter and ninety pages of tables of numbers related to natural logarithms.

He coined the term from the two ancient Greek terms “logos”, meaning proportion, and “arithmos”, meaning number; joining them to produce the word logarithm.

The technique was found to be very accurate and his work was translated into different languages and was also widely printed. His logarithms helped with trigonometric calculations in astronomy and navigation.

Napier moved to Merchiston Castle in Edinburgh in 1608 after the death of his father and lived there for the rest of his life.

His work concerning the computation of logarithms, “Mirifici logarithmorum canonis constructio” was published two years after his death in 1620.

A copy of Napier’s work of 1614 was sent to Henry Briggs, professor of Gresham College. Briggs made Napier’s method even easier by setting log of 1 at zero. Napier agreed with this suggestion but, due to ill health, left the responsibility of setting up the new logarithm table to Briggs. The new tables were published in 1624 and were called table of common logarithms.

Napier improved decimal notation that has been introduced by Simon Stevin and brought the decimal point into common use.

Napier presented a mechanical means of simplifying lattice multiplication calculations using “numbering rods” in his work “Rabdologiae, seu Numerationis per Virgulas Libri Duo” (Study of Divining Rods) published in 1617. The rods were made of ivory, so that they looked like bones, explaining why they became known as Napier’s bones. To multiply numbers the bones were placed side by side and the appropriate products read off.

Many mathematical functions like multiplication and division could be now be achieved mechanically. This device helped in the development of analog computers and slide rules.

He passed away the same year, from the effects of gout, on the 4th of April, 1617 aged 67.