Early Length Measurements

Probably some of the first measuring standards were portable, convenient to use, and always with one. The Old Testament measures Noah’s ark by cubits the length of a man's forearm or the distance from the tip of the elbow to the end of his middle finger. Many of our current standards originated from other body measurements. Our foot-rule started out as the length of a man's foot. Of course, the foot varies in length, so that for more accuracy a 16th century Teutonic surveyor decreed that "16 men will be selected from the group leaving church. The length of the left foot of each shall be taken and... "(averaged); an early example of hexadecimal system, easily divisible in geometric progression. Once the ancients started using arms and feet for measuring distance, it was only natural that they also thought of using fingers, hands and legs. An inch originally was the width of a man's thumb. It is probably no accident that the French word for thumb, "pouce", is also the word for inch. Twelve times that distance made a foot. Three times the length of the foot was the distance from the tip of a man's nose to the end of his outstretched arm. The distance very closely approximates what we now call the yard. The Roman Legion measured the length of their march by the "pace" , a distance equal to two strides. The Legion established the mile unit, consisting of the Latin "mille passum" meaning 1000 paces. The very short length measurements were done using grains of barley (barleycorns) placed on end. However, none of these were positive fixed dimensions or true standards.

Early Weight Measurements

With the invention of the balance, the Babylonians made a basic contribution. Instead of comparing the weights of two unknowns on the balance, they compared the weight of the unknown to a set of stones especially prepared for weight service. Archaeologists have found some of these stones finely shaped and polished, probably the world's first weight standards. Medieval English practice was to use the same concept, with the "stone" legally accepted as 14 pounds. The Egyptians and the Greeks used a wheat seed as the smallest unit of weight, a standard that was very uniform and accurate for the times. The grain is still in limited use as a standard weight. However, wheat seeds are no longer actually put in the pan of the balance scale. Instead, a weight that is practically the same as that of an average grain of wheat is arbitrarily assigned to the grain, and is nominally 1/500 of an ounce (avoirdupois), or 65 milligrams. The Arabs established a small weight standard for gold, silver and precious stones which often were a part of trade or barter deals. To weigh the small valuable quantities, they used as a weight standard a small bean called a "karob". This was the origin of the word "carat" which jewelers still use to express the weight of gems and precious metals.

The Romans set the popular standard for heavier weights. The Roman "Libra" (which gives us the abbreviation lb.) was defined as the weight of 7680 grains of wheat, fixing the grain as the basic measure. King Henry VIII went on to define the avoirdupois pound as 7000 grains. The French defined the troy pound (from Troyes, France, an important trading center in the Middle Ages) as 5760 grains for use in weighing jewels and precious metals. The Dark Ages for Standard Measurements the Roman Empire had codified by both length and weight measurements, established standards, and maintained a reference set of these standards in a temple, to be used by the entire civilized world. Tragically, after the fall of the Roman Empire, these standards were lost and there was no longer any uniformity.

In the Middle Ages, almost every town had its own standards of weights and measures, and there were variations between those of one trade and another. As late as the 18th century in Italy there were more than 200 units of length called the "foot". By the late 1700s, the measurements problem was heading for conflict. There were two outstanding systems in the Western World: the French system, pushed by the science-minded Revolutionary government and the English system, a follow-on of the Roman system. This period marks the dawn of the Metric system.