keywords: napier calculator arithmetic logarithm decimal
text: Napier's Chessboard Calculator Isn't Napier the logarithm guy? Yes indeed. A man of varied  talents, he popularized the modern decimal point notation and argued  that the Pope of 1593 was the Antichrist.    And created one of the first devices to automate binary  arithmetic. Using nothing more than a chessboard and some counters, he  developed ways to multiply, divide and even find the square roots of  binary numbers.