The principles of metrology summarized ahove, however, are modern compared to weights and measures themselves. Before man had developed beyond the savage state he felt the need of some methods of measurement. So old is the idea that there is found in Josephus the statement that Cain invented weights and measures. Upon the idea of numbers followed closely those of time, distance, and quantity. Measurement of time has been simplified by nature, which furnished the aboriginal, as well as the modern, standard, the diurnal rotation of the earth upon its axis. A measure of distance was easily furnished in the day's journey, as the Indian of the West indicates distance by the number of repetitions of the sign meaning front sunrise to sunset. As a smaller unit became necessary, the stride, or pace, came into use, and finally, as a still smaller unit, the dimensions of parts of the body ap pear. Although reference is made in Deuteron omy (ii. 5) to the 'foot breadth' and the foot came into very general use in Creek, Bonnin, and sub sequent times, nevertheless the common unit in Asia Minor and Egypt was the cubit, derived from the length of the forearm, from the point, of the elbow to the end of the middle finger. In the inscriptions and records of these coun tries continual reference is made to this unit and its subdivisions. Among the Creeks and Romans the pace and foot came into almost uni versal use, and by them were down to subsequent 1V1stern nations. The passes became the 'pace,' the mine (passuum) the 'mile,' and the pond us the `pound,' Which appear in most European nations until the present day. Under the Roman Empire the standards. were preserved in a Roman temple, and were the standards for the civilized world. With the fall of the Empire and the rise of small prineipalities, a chaotic condition as to standards developed which ex tended through the Middle Ages and thereafter, until in Italy alone, as late as the end of the eighteenth century, there were over two hundred lengths called the foot. Every little dukedom and principality had its own standards of weight and measure, and the insignificant intercourse between these small towns did not suffer from these conditions, but the maritime leagues felt the need of common standards.
An example of the method of deriving the standards in the sixteenth century in Cermany is given by the following quotation from lioebel's work on surveying: "To find the length of a rood in the right and lawful way, and according to scientific usage, you shall do as follows: Stand at the door of a church on a Sunday, and hid sixteen men to stop, tall ones and small ones, as they happen to pass out when the service is finished; then make them put their left feet one behind the other. and the length thus obtained shall be a right and lawful rood to measure and survey the land with, and the sixteenth part of it shall be a right and lawful foot." In England. we find Henry I. establishing the yard as the distance from the point of his nose to the end of his thumb, and Parliament seriously establishing standards of length and weight ac cording to grains of wheat or barley. Doubtless, few people realize that shoes are still num bered according to the length of a grain of barley, in a system of numeration by thirteens. We have, as example of other units from the dimensions of the body, the `fathom' (faethm, the embrace), the length of the two arms from tip to tip; the 'hand,' 4 inches; the 'span,' 9 inches; the 'finger,' IA of a yard; the 'nail,' 2 inches, from the tip of the thumb nail to the base joint. Yard is derived from the word gyrdan, meaning the girth of the body.
It might appear surprising that the length of the cubit should have remained rather con stant so long in Egypt, hut where such impor tant hnildings were constructed and such con tinuity of dynasties was maintained, it should not be surprising that the unit or standard of length should have remained constant. inasmuch as the standards would naturally be handed down from dynasty to dynasty, and indeed, if destroyed, could easily be recovered from the dimensions of existing buildings, just as to-day it would he possible to restore the foot from the dimensions and descriptions of existing struc tures. Just as a carpenter to-day might lose
a two-foot rule in the wall of a house, so 3U00 years ago an Egyptian stone mason lost his two cubit rule in the wall of a temple at Karnak. Subsequent ruin and excavation brought it to li(Mt. and allowed a direct comparison with the temple dimensions. At the present day, in some parts of t_hina. the first step toward building a house is making a measuring stick, according to which all materials are purchased and the dimen sions determined. This method suffices for simple exchange.
:7standards of quantity or weight seem to have developed in a still more arbitrary manner. The cuneiform tablets of Babylon tell of 'vessels' of oil and 'skins' of wine. the volume being as arbi trary as the 'jar' or 'amphora' of the Bomans. For dry produce the term often means simply a heap, large or small. With the introduction of the balance. weighing became possible, and pondus appears. designating essentially 'a weight.' ..Alany 'steel yards' and balances (see BALANCE) were unearthed amid the ruins of Pompeii. As the pondas seems to be a haphazard unit, so also is the stone (14 pounds), still used in England. and the base of such units as the hundredweight (cwt.) or 112 pounds (S stone), and the ton of 2240 pounds or 160 stone, also the bushel of 56 pounds (4 stone), etc.
The earliest systems of linear units seem to be based upon either the cubit (20.62 inches = 52.4 centimeters) or the digit (0.73 inch. or 1.85 cm.), probably derived from the breadth of the finger. The cubit appears first in Egypt in the Fourth Dynasty, and the great pyramid yields the value above given. Nevertheless, as might be ex pected. considerable variation occurs, even in Egypt (20.5 inches to 20.7 inches). The cubit was divided into hundredths, but as incommen surate, approximate subdivisions the one-seventh, 'palm,' and one-twenty-eighth, 'digit,' were used. Several extant cubit rods give an average of 20.65 inches. At the Nilometers it is 20.75. As multiples of the cubit (multi) the xylon, 3 cubits, walking staff. the neat, 4 cubits, and the klict of 40 'shits, are found along with the schoenas of 12,000 cubits. About the same time a similar unit appears in Babylon, especially as the half of 20.89 Undies or span of 10.44 inches, or 16 digits of 0.653 inches. A cubit of 20.5 inches is derivable from various buildings in Assyria and Babylonia. where a sexagesimal system ex isted. In Asia :Minor the cubit derived from temples appears as 20.55 inches at Ephesus. 20.62 invite- at Samos, while the stadium at Laodicea gives 20.94 inches. Three-fifths of the cubit of 20.75 inches, a eombination of the Egyptian decimal and the Assyrian sexary system. is the commonest of Greek derivatives (12.44 inches) occurring in the Propylaea, the Temple of .Egina, olympian course, etc. Other and less impor tant derivations from the cubit occur in re stricted localities or periods. The digit appeared about simultaneously with the cubit, and some confusion arose from the belief that it was one tm,enty-eighth of a cubit: in reality they appear to be iiicommensurate. although 10 digits were often indicated on cold! sticks as the 'lesser span.' Practically the same unit appears in Assyria. Persia, and Asia 7Alinor. The common Egyptian small unit of volume was the bon about 29 cid& inches. The artaba was the prac tical equivalent of the Attic metretcs. The Egyptian unit of weight was the lwt = 146 grains: 100 lot = 10 ate)! = 1 terra. 1n Baby lonia the talent = 360 stone = 3600 shekels = 66.4 pounds. The stadion appears very early as equal to one-thirtieth of a parasang, or about 14S meters. or 4S5 feet, the parasang being 14; 550 feet, or 2.76 miles. This is the old itinerary stadium, used in measuring distances from place to place. As examples of Greek measures of length the following may be given: 1 stadion = 6 plethra or length of a furrow.