when they are designed to do a specified work, that is conspicuously
the work they cannot possibly be induced to do. There, for instance,
was Bradley's famous steam-pump.

Some years ago Bradley invented a steam-pump for use on shipboard. He
claimed for it that it would pump about three times as many gallons in
a minute as any other pump, and he got some of his political friends
in Congress to use their influence with the Navy Department to have it
tried on one of the navy vessels. Finally he succeeded in having it
introduced upon a small steamer, which we will call the Water Witch;
and when everything was ready, the ship started upon a trial trip.
Soon after she got to sea, Bradley, who was aboard, said he would like
to try the pump upon the bilge-water to see how she worked.

The captain ordered the engineer to turn it on, and the machine
operated apparently in the most beautiful manner. In about an hour one
of the officers reported that the water was gaining rapidly in the
hold, and the captain sent some men down to discover where the leak
was. They came back and reported that they couldn't find the hole, but
that the water was pouring in somewhere in frightful quantities.

Then some of the officers went down and spent half an hour in water
up to their waists feeling around after that awful hole, but they
couldn't ascertain where it was. The only thing that they were certain
of was that the water was steadily gaining on them, and the ship was
certain to sink unless something was done. All this time Mr. Bradley's
pump was working away, and the captain continually enjoined the
engineer to give it greater speed.

Then the captain himself went down and made an examination; and