54 THE WORLD MACHINE 



six sides, each equal to the radius, could be described within 

 every circle, it was natural that they should make such a 

 division. Doubtless the earlier division had been into the 

 twelve periods corresponding to the twelve lunations which 

 their crude observations taught them to believe made up the 

 year. The change of division marked the separation of the 

 theoretical from the practical. 



The three hundred and sixty divisions of the circle were 

 named steps, or degrees. As their observations grew more 

 accurate they split each of these into sixty parts, partes minutce, 

 whence our minutes ; these into sixty more, partes minutce 

 secundce, whence our seconds. The day and the night they 

 divided each into twelve parts, corresponding doubtless to the 

 twelve divisions of the year. The first time-keeper was the 

 sundial ; its face was half a circle. It was natural that they 

 should have employed these minor divisions of the circle to 

 mark the subdivisions of the hour. 



Along with this application of numbers to time came a 

 parallel application to weights. Primitive man had made 

 another prodigious step when he had discovered the principle 

 of the balance. Our word " pound " comes from the same 

 root as " pendant," meaning " to hang," that is, " to weigh." 

 The ounce was the twelfth part of this, and meant simply the 

 twelfth part ; it is the same word as inch. 



Even earlier must have been the application of numbers to 

 measures. There was need first of all to define the exploits of 

 the chase or of the march ; this would evidently be in units 

 of the distance an ordinary man might cover, travelling steadily 

 through the day. With fixed habitations and the subdivisions 

 of fertile areas into definite plots came corresponding sub- 

 divisions of the day's march. It is evident that the handiest 

 units were the average length of feet and hands. It is a rather 

 curious reflection of our Saxon civilisation that alone among 

 the nations of the earth we should still be employing as our 

 unit of a length the human foot, just as did the primitive folk 

 of twenty or thirty thousand years ago. Up to within a recent 

 time the French measure of an inch was the pousse, the thick- 

 ness of a thumb. Fractions of this were expressed in lengths 

 like our English barley-corn, just as a single grain formed a 

 subdivision of the ounce in weight. 



A pace was simply a step, a yard was a club or stick, doubt- 



