1122 



WEIGHTS AND MEASURES 



Troy Weight. 



Apothecaries' Weight. 



Avoirdupois Weight. 



Measures of Length. The imperial standard yard is divided into 3 feet, and each 

 foot into 12 inches, and its length is fixed (see Act of Parl. 5 Geo. IV. c. 74) by refe- 

 rence to the length of the pendulum vibrating seconds in the latitude of London, in a 

 vacuum at the level of the sea ; the former being to the latter in the proportion of 36 

 imperial inches to 39-1393 imperial inches. The length of the seconds pendulum at 

 Greenwich is 39-13929 inches; at Leith Fort (nearly the parallel of Glasgow), under 

 the same circumstances.it is 39-1555 imperial inches ; and at Now York, 39-1017 

 imperial inches. The imperial standard yard may, however, be more distinctly de- 

 nned as the distance between the points of oscillation and suspension of a pendulum 

 vibrating in a mean solar day (in a vacuum at the level of the sea,) at London 90,088 

 times. The Scotch standard ell (the use of which is now abolished,) measured 37 

 imperial inches. 



An inch, formerly divided into 3 barleycorns, is now the smallest lineal measure to 

 which a name is given, but subdivisions aro used for many purposes. 



Cloth Measure. 



