DIVIDING THE CIRCLE

摘要

I can date the beginning of my interest in engineering workshop technology fairly accurately to August 1967. I was recently married and waiting to start work, so my new wife and I spent a week exploring London. One of the first places we visited was the National Maritime Museum in Greenwich and at that time there was an exhibition about Captain Cook. We admired the luminous landscapes of South Sea island scenes painted by William Hodges and I inspected some of the navigational instruments of a type used by Cook on his voyages. I was fascinated by the fineness of the divisions on the angle-measuring instruments such as quadrants and sextants, and began to wonder how they had been made. My father thought that screw threads came into the story somehow (as indeed they do) and that led me to buy a copy of Chapman's Engineering Workshop Technology (Ref.1), a text that even then was beginning to show its age. However, it gave me a start that led a few years later to the ownership of a small lathe and to some understanding about circular division.