Of Weights and Measures, 
15 
as the standards in this country are always referred to 
the temperature of 60° or 62° (and the latter is now pre- 
ferred) the expansion of brass (which is the material of 
which the standards are made) from 32 n to 62° must al- 
ways be taken into account ; for it is obvious that if the 
English standard is at 62° and the French at 32°, the 
latter will measure a less quantity of the former than if 
both were at 32°. The number 39.38S7& therefore, 
which is the equivalent to the French metre when both 
are at 32°, must be diminished in the proportion in which 
brass expands 30 degrees, which is estimated by Dr. 
Young, from Bordas experiments, to make the equiva- 
lent to the metre to be 39.371 English inches, the stan- 
dard of the metre being at 3£°, and that of the English 
inch at 62 °. 
All the new French measures increase and decrease 
in decimal proportion, a distinctive prefix being put to 
the term by which the integer is called. These prefixes 
are Deca-, Hecto-, Kilo-, and Myria-, (taken from the 
Greek numerals) to express the multiplication of the in- 
teger by 10, 100, 1000, and 10000 respectively ; and 
Deci-, Centi-, and Milll-, (from the Latin numerals) to 
express the division of the integer by 10, 100, or 1000. 
Or according to the following scale, taking the metre as 
the integer. 
The metre is the integer of the measure of length, and 
from it all the measures of surface, capacity, and weight, 
are deduced in the following way. 
For square dimensions the metre or its parts squared 
are employed. When used for measuring land the term 
Metres 
Metres 
1 Metre zr 1. 
I Myriametre “ 10000 
1 Kilometre ZZ 1000 
1 Hectometre ZZ 100 
1 Decametre ZZ 10 
1 Decimetre zz 0.1 
1 Centimetre zz 0.01 
1 Millimetre zz 0.001 
