the Subject of Weights and Measures. 173 



much more labour and inconvenience in its internal relations than 

 it could ever be expected to save in the operations of foreign 

 commerce and correspondence, which always are, and always 

 must be, conducted by persons to whom the difficulty of calcu- 

 lation is comparatively inconsiderable, and who are also remune- 

 rated for their trouble, cither by the profits of their commercial 

 concerns, or by the credit of their scientific acquirements. 



3. The subdivisions of weights and measures, at present em- 

 ployed in this country, appear to be far more convenient for prac- 

 tical purposes than the decimal scale, whicli might perhaps be 

 preferred by some persons for making calculations with quantities 

 already determined. But the power of expressing a third, a fourth, 

 and a sixth of a foot in inches, without a fraction, is a peculiar ad- 

 vantage in the duodecimal scale, and for the operations of weigh- 

 ing and of measuring capacities, the continual division by 2 ren- 

 ders it practicable to make up any given quantity,with the smallest 

 possible number of standard weights or measures, and is far pre- 

 ferable in this respect to any decimal scale. We would there- 

 fore recommend, that all the multiples and subdivisions of the 

 standard to be adopted should retain the same relative propor- 

 tions to each other as are at present in general use. 



4. The most authentic standards of length which are now in 

 existence being found upon a minute examination to vary in a 

 very slight degree from each other, although either of them 

 might be preferred without any difference that would become 

 sensible in common cases, we beg leave to recommend, for the 

 legal determination of the standard yard, that which was em- 

 ployed by General Roy in the measurement of a base on Houn- 

 slow-heath, as a foundation for the trigonometrical operations 

 that have been carried on by the Ordnance throughout the coun- 

 try, and a duplicate of whicli will probably be laid down on a 

 standard scale by the Committee of the Royal Society appointed 

 for assisting the Astronomer Royal in the determination of the 

 length of the pendulum ; the temperature lieing supposed to be 

 62 degrees of Fahrenheit, when the scale is employed. 



5. We propose also, upon the authority of the experiments 

 made liy the Committee of the Royal Society, that it should be 

 declared, for the purjiose of identifying or recovering the length 

 of this standard, in case that it should ever be lost or impaired, 

 that the length of a pendulum vibrating seconds of mean solar time 

 in London, on the level of the sea, and in a vacuum, is o!)'l372 

 inches of this scale; and that the length of the metre cnqjloyed 

 in France, as the tcn-miilioiith part of the (juadrantal arc of the 

 meridian, has been foimd cijual to 39*3GiM inches. 



(>. Tiie definitions of measures of capacity are obviously capa- 

 ble of being immediately deduced from their relations to measures 



of 



