1 6 ASTRONOMY. 



The French Metrical System. 



All the measures of the French metrical system 

 rest upon one sole base, supposed to be found in na- 

 ture, viz. the quarter of the terrestrial meridian; and 

 the division of these measures is subjected to the 

 decimal order employed in arithmetic. 



The result of operations carried on to measure the 

 meridian which traverses France, has given 57,027 

 French toises for the length of the degree, from 

 whence, for the 90 degrees composing the quadrant 

 of that arc, 5,132,430 toises are found. The last 

 quantity, divided by ten millions, gives a length of 

 3 feet, no inches, 11 lines, and 44 hundredths 

 (3:0:11: 44), which has been fixed on as the prime 

 unit of linear measure, and named the metre.* The 

 Paris foot is to that of London as 864 to 811, or as 

 16 to 15 nearly. 



In the calculation of these measures, by proceed- 

 ing a maximis ad minima, and thus still dividing, and 

 consequently still diminishing any error, the further 

 we proceed, it will in the end, when we come to ordi- 

 nary measures, such as feet, become for practical 

 uses quite insensible. 



No two Portions of any Meridian exactly similar. 



The French linear measures of the ten-millionth 

 part of a quadrant of the meridian has been found 

 full of absurdities and Defects, it having been ascer- 

 tained that no two portions of any one meridian on 



* Notwithstanding the pains taken and vast expense incurred, 

 the French metrical system has wholly failed of success in prac- 

 tice, and never was generally adopted. It was found that the 

 common people could not be brought to understand the division 

 by ten, nor to adopt the Greek terms then introduced. The con- 

 sequence has been, that there is now a greater diversity of weights 

 and measures than existed antecedent to the new system, which 

 was to produce perfect uniformity. 



