[To SIDI EDITOR OF TEE "SrEcriroa."J
SIR,—The great difficulty about our measures and coinage is that every one has learnt to count in tens, and that it is practically impossible to get people to count in twelves. It can scarcely be denied that if the world were free to begin its arithmetic de novo, the best system would be to count in twelves. I believe the decimal system is attributed to the fact that one has ten fingers, but the advantages of a duo- decimal system are so considerable that, if this be so, one must almost regret we have not twelve.
If only the metric system of weights and measures had been in " twelves "- instead of " tens " it would in all proba- bility have swept the world a long time ago, and we might even possibly have had a universal duodecimal coinage and a duodecimal arithmetic. Meanwhile we have the practical desirability of counting in twelves for many matters of daily life, such as twelve pennies to the shilling and twelve inches to the foot, whilst our system of arithmetic compels us to count in tens. Apart from strongly established custom, the best solution would be to learn to count in twelves,—that is, to learn the duodecimal arithmetic. But this seems too great a demand, so that it would appear probable that in time we shall be swamped with the decimal metric system and a decimal coinage, and have to forgo for ever the advantages of ready division into thirds and quarters which make tho duodecimal system so superior.—I am, Sir, ese.,