The work accomplished by such men as Gladstone and Roosevelt is incomprehensible to most of us who have never undertaken more than puny tasks. These men retain their strength and in no way seem to be undermining their health by the accomplishment of their <p 14> Herculean labors. Body and mind seem to respond to the demands made upon them. Their periods of sleep and their vacations seem to be no more than the hours and days of rest required by those of us who accomplish infinitely less. No need, however, to go beyond the field of business or industry to find men whose super-energy has carried them to epochial discoveries or feats of organization. The invention of the incandescent lamp by Edison is said to have been accomplished, for instance, only after forty-eight hours' continuous concentration on the final problem of finding the right carbon filament and determining the proper degree of vacuum in the inclosing bulb. Months of experiment and research had gone before; eighteen hours a day in the laboratory had been no uncommon thing for the inventor and his assistants, but in the last strenuous grapple with success his own physical and mental powers were alone equal to the strain. Not once during the two days and nights did he rest or sleep or take his attention <p 15> from the successive tests which led up to the assembling of the lamp which lights the world's work and play. The steel blade that is used seems to last as long as the one which is allowed to lie idle. The wearing out in the one case does not seem to be more destructive than the rusting out in the other. We have a choice between wearing out and rusting out. Most of us unwittingly have chosen the rusting process. This, indeed, may be said to be Edison's regular method of work, as it is the method of many other men who have accomplished great things in science and industry. Both mind and body have been trained and accustomed to exertions which seem quite impossible to ordinary individuals. Many persons find that increased intellectual activity results in less fatigue and greater achievements. As a student I did my best work and enjoyed it most the year I carried the greatest number of courses and assumed the most outside duties. In my <p 16> capacity as adviser to college students I find many who are able to accomplish thirty per cent more work than is expected of college students but fail to do equally well the regular amount. There are others who can carry the regular amount but not more without injury to their health.