CHAPTER IV 



MASS AND ITS MEASUREMENT 



The mass of any body is the quantity of matter it con- 

 tains. In our country the standard or unit of mass is the 

 quantity of matter contained in a lump of platinum of a certain 

 size which is kept at the Exchequer Chambers. This amount of 

 matter is called the imperial standard pound avoirdupois, 

 and we speak of the mass of any other body as being a certain 

 number of times more or less than the standard pound, that is, 

 containing so many more times as much (or as little) matter as 

 that contained in the imperial standard pound. Unfortunately, 

 this is not a universal standard ; in France they have a standard 

 of their own. It is kept at Paris, and is called a kilogram, and 

 the system of masses founded upon it is used in all scion tiiic 

 work throughout the world. 



Units of Mass in the British System. As the reader knows 

 very well, the unit of mass, the pound avoirdupois, to which 

 attention has just been called, is not the only standard used in 

 this country in speaking of the mass of a given body ; multiples 

 and submultiples of it, as shown in the following familiar table, 

 are also adopted. A comparison of this with the corresponding 

 beautifully simple table of the metric system will do more than 

 any words to show how cumbersome and inconvenient the' 

 British system is : 



16 drams make 1 ounce (1 oz.). 



16 ounces ,, 1 pound (1 11).). 



14 pounds ,, 1 stone (1 st.). 



2 stones or 28 pounds ,, 1 quarter (1 qr.). 



4 quarters or 8 stones ,, 1 hundredweight (1 cwt.), 

 20 hundredweights ... ,, 1 ton. 



