448 THE YARD, PENDULUM, AND METRE. 



very speedily followed both in America and Russia, so 

 soon as the reason of the thing and the trifling amount 

 of the change came to be understood. And even with- 

 out legislation the relation between the proposed new or 

 geometrical measure and the imperial ones is so simple 

 and striking fixing itself so easily in the memory, and the 

 conversion from one to the other so ready, that, were 

 there no other reason, it might almost be questioned 

 whether it would be worth while to make the change. 



(31.) But there is another reason, and I think a decisive 

 one. Hitherto I have said nothing about our weights 

 and measures of capacity. Now, as they stand at pre- 

 sent nothing can be more clumsy and awkward than the 

 numerical connexion between these and our unit of 

 length. A grain is denned as the weight of distilled 

 water, so that 252724 of such grains at the freezing 

 temperature, or 252-46 at that of 62 Fahr. which is the 

 standard temperature of our imperial yard, shall fill a 

 cubic inch. Of such grains, so defined, the pound con- 

 tains 7000, the ounce 43 7 \, and the gallon of water at 

 62, 70,000. According to this system, the cubic foot of 

 water at our standard temperature weighs 997-145 oz., 

 falling short of 1000 oz. by very nearly 3 oz. However 

 tempting this approximation might appear, still, in the 

 absence of any more cogent reason, the commissioners 

 who recommended our system of weights and measures 

 legalized in 1824 forbore to recommend such a change 

 in the ounce (about ij grain) as would have brought it 

 about ; though the rule that a cubic foot of water weighs 

 1000 ounces is still handed down as a rough and ready 



