In this case all standards of "capacity" would be changed everywhere.

But the fact that all things are _possible_ is no excuse for talking foolishly.
It is true that in 1870 no man could have predicted Germany's capacity in 1910.

We cannot expect to legislate for a generation or more.

The secular changes in man's economic condition and the liability of human forecast to error are as likely to lead to mistake in one direction as in another.

We cannot as reasonable men do better than base our policy on the evidence we have and adapt it to the five or ten years over which we may suppose ourselves to have some measure of prevision; and we are not at fault if we leave on one side the extreme chances of human existence and of revolutionary changes in the order of Nature or of man's relations to her.