Second, every REDUCTION is made almost instantaneously by merely moving the decimal point. There are no reductions performed by multiplying by 1,728 or 5,280, etc., or dividing by 5 1/2, 30 1/4 or 31 1/2, etc., and hence there is A GREAT SAVING in the labor and time of making necessary calculations.
Third, there are but FIVE tables in the metric system proper, these taking the place of from twelve to fifteen in our system (or lack of it). These are linear, square, cubic, capacity and weight.
Fourth, any one table is about as easy to learn as our United States money table, and after one is learned, it is much easier to learn the others, since the same prefixes with the same meanings are used in all.
Fifth, the weights of all objects are either known directly from their size, or can be very quickly found from their specific gravities.
Sixth, the subject is made so much easier for children in school that a conservative expert estimate of the saving is two thirds of a year in a child's school life. The rule in this country is eight years of arithmetic, the arithmetic occupying about one fourth of the child's activity. With metric arithmetic substituted for ours, what it now takes two years to prepare for, could be easily done in 1 1/3 years. This involves an enormous waste of money and energy every twelvemonth.
Seventh, only ONE set of measures and ONE set of weights are needed to measure and weigh everything, and ONE set of machines to make things for the world's use. There would be no duplication of costly machinery to enter the foreign trade field, thus securing enormous saving. It is well known that the United States and Great Britain have lost a vast amount of foreign commerce in competition with Germany and France, because of their non-use of the metric units. Britain realizes this and is greatly concerned over the situation.
Eighth, every ordinary practical problem can be solved conveniently on an adding machine. Our adding machines are used almost solely for United States money problems.
Ninth, no valuable time is lost in making reductions from common to metric units, or vice versa, either by ourselves or foreigners. To make our sizes in manufactured goods concrete to them foreign customers have to reduce our measures to theirs and this is a weariness to the flesh.
Tenth, the metric system is wonderfully simple. All the tables with a rule to make all possible reductions can be put on a postal card.[1]
[1] See article by the writer in Education (Boston), Dec., 1894.