When every allowance has been made for the material changes which the progress of this century threatens, it is easy to see that certain, present-day problems will continue to trouble our successors. Some things which perplex ourselves will, I think, work out their own remedy. Others will remain the subject of solutions not difficult to be imagined in advance.
One chief difficulty which will infallibly confront the immediate future, and even the future that is more remote, arises out of the simple fact that the race of man tends to increase numerically at a speed greater than our devices for its accommodation can quite conveniently cope with. The population of the world not only increases, but increases at compound interest. Nor is this all. Improved sanitation, better habits of life, and the progress of medicine, prolong lives that in the conditions of last century would have been shortened, and the rate of increase is thus further accelerated,
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