History of Computers - Napier's Bone

Napier's Bone- The world's first practical computer

Introduction

Napier's Bone was the world's first practical computer. Created by John Napier, this new invention could multiply, divide, and find roots [1]. One could also calculate square and cube roots [2].

Overview

Napier's Bone was made up by a "plate" and a set of "rods" with one plate for multiplication, division, and finding roots. The rods each represented a number located on the plate. This predecessor was based on Arab mathematics and lattice multiplication, which originated from Rabdology, the method of performing operation by Napier's Bone. The rod's surface had nine squares with each square having two halves divided by diagonal line, except the top square. The first square held a single digit and the other squares held that number's double, triple, quadruple, quintuple, and so on until the last square contains nine times the number in the top square. The digits of the product were written one to each side of the diagonal. Numbers less than ten occupied lower triangles with zero in the top [3].

Significance

Napier's Bone was quite influential in the history of the computer, although sometimes overshadowed its forerunner, the slide rule [2]. Without Napier's Bone, there would not be the slide rule. Napier's Bone started this fast reaction causing everyone to try to find an efficient and fast process to perform calculations. It also led to the Genaille roots, whcih allowed the products to simply be read off directly without the need for carriers [4].