The following case, which has come to my knowledge, illustrates what I mean.
A number of new machines were installed in a certain shoe factory, and as a result there was a heavy increase in production even though there was no increase in the labor force.

Some of the workmen were instructed in the use of these machines by special demonstrators sent out by the makers of the machines.

These men, by reason of their special aptitudes and the fact that they were not called upon to operate the machines continuously nine hours every day, week in and week out, but only for an hour or so at special times, were naturally able to run the machines at their maximum capacity.

When these demonstrators had left the factory, and the company's own employees had become used to operating the machines at a fair rate of speed, the foreman of the establishment gradually speeded the machines and demanded a larger and still larger output, constantly endeavoring to drive the men on to greater exertions.
Even with a slightly less maximum capacity, the introduction of this machinery resulted in a great increase over former production with the same amount of labor; and so great were the profits from the business in the following two years as to equal the total capitalized stock of the company.

But not a cent got into the pay envelope of the workmen beyond what they had formerly been receiving before the introduction of this new machinery, notwithstanding that it had meant an added strain, physical and mental, upon their energies, and that they were forced to work harder than ever before.