TABLE 3. 

 TABLES FOR CONVERTING U. S. WEIGHTS AND MEASURES." 



(I) CUSTOMARY TO METRIC. 



The only authorized material standard of customary length is the Troughton scale belonging to the United States 

 Office of Standard Weights and Measures, whose length at 59.62 Fahr. conforms to the British standard. The yard 

 in use in the United States is therefore equal to the British yard. 



The only authorized material standard of customary weight is the Troy pound of the Mint. It is of brass of un- 

 Jinown density, and therefore not suitable for a standard of mass. It was derived from the British standard Troy 

 pound of 1758 by direct comparison. The British Avoirdupois pound was also derived from the latter, and contains 

 7,000 grains Troy. 



The grain Troy is therefore the same as the grain Avoirdupois, and the pound Avoirdupois in use in the United 

 States is equal to the British pound Avoirdupois. 



The British gallon = 4.54346 litres. 



The British bushel = 36.3477 litres. 



The length of the nautical mile given above and adopted by the U. S. Coast and Geodetic Survey many years 

 ago, is defined as that of a minute of arc of a great circle of a sphere whose surface equals that of the earth (Clarke's 

 Spheroid of 1866). 



* Quoted from sheets issued by the United States Office of Standard Weights and Measures. 

 SMITHSONIAN TABLES. 



9 



