was mostly due to the fact that Arnold
had passed an almost entirely sleepless night, and had only begun to
doze off towards morning. The events of the previous evening kept on
repeating themselves in various sequences time after time, until his
brain reeled in the whirl of emotions that they gave rise to.

Although of a strongly mathematical and even mechanical turn of mind,
the young engineer was also an enthusiast, and therefore there was a
strong colouring of romance in his nature which lifted him far above
the level upon which his mere intellect was accustomed to work.

Where intellect alone was concerned--as, for instance, in the working
out of a problem in engineering or mechanics--he was cool,
calculating, and absolutely unemotional. His highly-disciplined mind
was capable of banishing every other subject from consideration save
the one which claimed the attention of the hour, and of incorporating
itself wholly with the work in hand until it was finished.

These qualities would have been quite sufficient to assure his
success in life on conventional lines. They would have made him rich,
and perhaps famous, but they would never have made him a great
inventor; for no one can do anything really great who is not a
dreamer as well as a worker.

It was because he was a dreamer that he had sacrificed everything to
the working out of his ideal, and risked his life on the chance of
success, and it was for just the same reason that the tremendous
purposes of the Brotherhood had been able to fire his imagination
with luridly brilliant dreams of a gigantic world-tragedy in which
he, armed with almost supernatural powers, should play the central
part.

This of itself would have been enough to make all other
considerations of trivial moment in his eyes, and to bind him
irrevocably to the Brotherhood. He saw, it is true, that a frightful
amount of slaughter and suffering would be the price either of
success or failure in so terrific a struggle; but he also knew that
that struggle was inevitable in some form or other, and whether he
took a part in it or not.

But since the last sun had set a new element had come into his life,
and was working in line with both his imagination and his ambition.
So far he had lived his life without any other human love than what
was bound up with his recollections of his home and his boyhood. As a
man he had never loved any human being. Science had been his only
mistress, and had claimed