elf capable, at that
hour of the day of rest, of battering down Gibraltar or of upbuilding
the whole human race, must account himself a failure.

"I'll do it," he murmured, drowsily, to himself, and he did. How he did
it was Jarley's own secret, and while he confides many things to me,
this secret he kept, and still keeps. All I know is that he fitted up a
play-room for Jack on the attic floor, and by means of an apparatus, the
peculiarities of whose construction he alone knows, he managed after a
while to store up the superfluous energy which Jack expended upon
everything that he did. Every time Jack turned a somersault he
contributed, unknown to himself, something to the growing bulk of
hoarded force in the reservoir provided for its reception. All the
strength necessary for the somersault was devoted to that operation. The
superfluity went to the reservoir. So, also, when in his play of scaling
imaginary rocks after fictitious wild beasts he endeavored futilely to
walk up the play-room wall, the unavailing energy went to augment the
stores from which Jarley hoped to extract so much that would prove of
value to the world.

When the reservoir was full the question that confronted Jarley was as
to the value of its contents, and to ascertain this he resolved upon an
experiment upon himself. No one else, he believed, would be willing to
subject himself to the experiment, nor did he wish at that time to let
others into his secret. Even Mrs. Jarley was not aware of his efforts,
and so he made the experiment. He liquefied the energy Jack had wasted,
and upon retiring one night took what he considered to be the proper
dose for the test. The effect was remarkable.

When he rose up the next morning he experienced a consciousness of power
that reminded him of sundry tales of Samson. But there was one drawback.
He did not seem quite able to control himself. For instance, instead of
dressing in the usual dignified and quiet way, he found himself prancing
about his room like a young colt, and while he was taking his bath he
had a yearning for objects of juvenile _virtu_ which had for many years
been strangers to his tub. He was not at all satisfied with his dip
plain and unadorned, and he had developed an unconquerable aversion for
soap. It was all he could do to restrain his inclination to call
vociferously for a number of small tin boats and birch-bark canoes,
without which Jack never bathed. He did conquer it, however, and at