CHAPTERS BY WACEK KIJEWSKI

1 || 2 || 3 || 4 || 5 || 6 || 7 || 8 || 9 ||10 || 11 || 12 || 13 || 14 || 15

# Chapter 01  A History of Measurement

Living in the twentieth century, we are familiar with the accurate measurement of time, distance, weight, volume, and so on. But imagine life in Stone Age times, many thousands of years ago, when there were no sophisticated instruments in use. Months were measured by noting the changing shape of the moon and then notching a piece of wood in order to record that change. The Egyptians several thousand years ago used a shadow stick to measure the passage of time. This gave rise to the sundial which was in universal use before clocks were invented in the thirteenth century. (Personal clocks did not come into use for another two hundred years!) The Egyptians also used the position of stellar constellations to draw up a calendar, and held celebrations when notable changes occurred.

Thousands of years ago our ancestors used the length of an arm, finger or foot as units of measurements. The Romans, between 40 BC and AD 50 spent so much time marching across various countries that they recorded distance in miles each mile comprising a thousand footsteps. Milestones marked the distance between villages. Today, kilometer stones are still used in most countries to mark the distance between major towns. Distances between planets are common knowledge. Length, in many instances, can be measured in a fraction of a millimeter.

Some measurements have been in use for centuries, for example the width of a hand (about 10 cm) which has been used to measure the height of a horse and still in use today. You can see that any convenient measure can be used as a unit! It is important to remember however that measurements, although widely used for thousands of years, were neither related nor standardized. The British yard was fixed as 0.9144 meters only in 1969. In force until then was King Henry I's rule: “legal is yard the distance from the tip of my nose to the tip of my middle finger”. The meter actually originated in France soon after the French Revolution in the eighteenth century, and was defined as one ten-millionth of the distance along the Earth's surface between the Equator and the North Pole!

 
 

Do you like anecdotes, interesting and challenging problems, fun facts, puzzles, jokes related to metric system and measurement? Read them in the 2006 on-line edition of "SI Units, Conversion and Measurement Skills",186 pp.