John Napier (nā´pēr, nəpēr´), 1550–1617, Scottish mathematician and theologian. He invented logarithms and wrote Mirifici logarithmorum canonis descriptio (1614), containing the first logarithmic table and the first use of the word logarithm. His Rabdologiae (1617) gives various methods for abbreviating arithmetical calculations. One method of multiplication uses a system of numbered rods called Napier's rods, or Napier's bones; this was a major improvement on the ancient system of counters then in use. In 1619, after Napier's death, his Mirifici logarithmorum canonis constructio, which gave the method of construction of his logarithms, was published by his son Robert and edited by Henry Briggs. Napier introduced the decimal point in writing numbers. Napier was also an outspoken exponent of the Protestant cause. His religious writings include A Plaine Discovery of the Whole Revelation (1593), the earliest Scottish interpretation of the scriptures.