THE HETEIC SYSTEM. 
57 
between tlie seconcPs pendulum and tlie meter. Precise!}^ with 
a view to establish the most efficient safeguard of the primary 
standard^ Borda had determined with the greatest nicety the 
dimensions of the pendulum beating seconds at Paris^ which 
in fact approach most nearly to those of the meter itself, being 
0“*_,99385^ the difference therefore being less than of the 
meter. With these data_, by a fresh determination of the length 
of the second^s pendulum_, invariable as this length is at the 
same latitude_, temperature^ and level (of the sea), a new 
standard meter, exactly equal to the original, could be con- 
structed. The Academy had previously resolved that the unit 
of length, whatever might be its value, should form the basis 
of the new system, the prototype, to which all other units 
whether of surface, volume, or weight were referable; and 
accordingly we perceive how, in the most skilful manner, this 
luminous idea has been realised, and the unity of the whole 
system exemplified. It was also resolved that the number 10 
should be the unique ^ factor of the system, so that the 
different scales of measurement might be in harmony with our 
system of numeration, which is decimal, and all quantities be 
expressed in decimal numbers : hence the greatest facility and 
despatch were ensured in the necessary arithmetical operations. 
The Grreek numerical prefixes, deca, hecto, kilo, myria, were 
chosen for the multiples, and the Latin, deci, centi, milli (by 
convention), for the submultiples or fractions of the various 
denominations . 
Thus Lixear Measure assumes the most simple and com- 
prehensive form, as in the following sketch ; — 
jNIyriameter . . . 
Kilometer 
Hectometer . . . 
Dekameter ... 
Meter 
Decimeter 
Centimeter . , . 
^Millimeter . . . 
10000 meters. 
1000 „ 
100 „ 
Tir 55 
irhj 55 
TuVtT 55 
Moreover, any one of these multiples or fractions may be 
employed as a distinct unit, whenever it is convenient, and 
decimalised accordingly. The French usually express great 
lengths in kilometers or even in myriameters ; for example, the 
distance between two towns is said to be 32 mjwiameters and 
5 kilometers, and this is written 325 kilom. (equivalent to 
about 203 English miles), and may be enunciated either way. 
The length of a canal is said to be 48 kilometers 7 hectometers, 
and this is written 48 k.m., 7 (equivalent to about 30 miles 
and a fraction). On the contraiy, lengths very minute are 
