THE ART OF WEIGHING AND MEASURING. (J 1 7 



foot constituted the talent, or larger unit of weight, and that the six- 

 tieth or fiftieth parts of the talent constituted, respectively, the Chal- 

 dean and Egyptian values of the mina, or lesser u»nt of commercial 

 weight. Doubtless these weights varied considerably at diiferent times 

 and places, jnst as the modern pound has varied, but the relations stated 

 are believed to have been the original ones. The ancient Chaldeans 

 used not only the decimal system of notation, which is evidently the 

 primitive one, but also a duodecimal system, as shown by the division 

 of the year into twelve months, the equinoctial da^^ and night each into 

 twelve hours, the zodiac into twelve signs, etc., and a sexagesimal sys- 

 tem by which the hour was divided into sixty minutes, the signs of the 

 zodiac into thirty i)arts or degrees, and the circle into three hundred 

 and sixty degrees, with further sexagesimal subdivisions. The duo- 

 decimal and sexagesimal systems seem to have originated with the 

 Chaldean astronomers, who, for some reason which is not now evident, 

 preferred them to the decimal system, and by the weight of their scien- 

 tific authority impressed them upon their system of weights and 

 measures. Now observe how closely the scientific thought of to day 

 repeats the scientific thouglit of four thousand years ago. These old 

 Chaldeans took from the human body what they regarded as a suitable 

 unit of length, and for their unit of mass they adopted a cube of water 

 bearing simple relations to their unit of length. Four thousand years 

 later, when these simple relations had been forgotten and impaired, 

 some of the most eminent scientists of the last century again undertook 

 the task of constructing a system of weights and measures. With 

 them the duodecimal and sexagesimal systems were out of favor, while 

 the decimal system was highly fashionable, and for that reason they 

 subdivided their units decimally instead of duodecimally, sexagesi- 

 mally, or by i)owers of two ; but they reverted to the old Chaldean 

 device for obtaining simple relations between their units of length and 

 mass, and to that fact alone the French metric system owes its survival. 

 Every one now knows that the meter is uot llie ten-millionth part of a 

 quadrant of the earth's meridian, and in mathematical physics, where 

 the numbers are all so complicated that they can only be dealt with by 

 the aid of logarithms, and the constant n^ an utterly irrational <puintity, 

 crops up in almost every integral, mere decimal subdivision of the units 

 counts for very little. But in some departments of science, as, for 

 example, chemistry, a simple relation between the unit of length (which 

 determines volume), the unit of mass, and the unit of specific gravity is 

 of prime importance, and wherever that is the case the metric system will 

 be used. To engineers such relations are of small moment, and conse- 

 quently among English-speaking engineers the metric system is making 

 no progress, while, on the other hand, the chemists have eagerly adopted 

 it. As the English yard and pound are the direct descendants of the 

 Chaldean-Babylonian natural cubit and mina, it is not surprising that 

 the yard should be oidy O.i.S ol an \\\('\\ shorter th.an the double cubit. 



