m of field signalling, extensively employed by the British
during the Boer war, since wireless had not at that time been at all
perfected, a man stands on a slight elevation, and catches the rays of
the sun on a great reflector. Those flashes are visible for many miles
in a clear atmosphere, in a flat country, and the flashes, of course,
are practically instantaneous.

"We don't need to worry about wireless for communications of a few
miles," said Durland. "The system of signalling that depends on seeing
flashes, smokes, flags and other signals, is as old as warfare, really.
The Indians, in this country, used to send news an astonishing distance
in an amazingly short time. They used smokes, as we know, since we have
all worked out those signals ourselves from time to time. And all
nations in time of war have employed relays of men with flags, stationed
at fixed intervals for scores of miles, for the sending of despatches
and important news. Napoleon used the system on a great scale, and,
until the telegraph was invented and made practicable for field work,
that was the only way it could be done."

"The telegraph was first used in our Civil War, wasn't it, sir?" asked
Tom Binns.

"Yes. But even then it was done in a very crude way. There was none of
the modern elaborate work of field telegraph systems. Nowadays, you see,
an army builds its telegraph lines as it goes along. Then they were
dependent upon the lines already built, mostly along the railroad
tracks. The first really great war in which such systems were in use was
the struggle between Russia and Japan. The French and the Germans didn't
have them in their war."

A few minutes later an orderly from the building in which the field
telegraph station had been established came running up to Durland.

"Despatch from General Harkness, Captain," he said, saluting, and
Durland took the slip of paper. He flushed with pleasure as he read it.

"Concentrate your troop at Hardport," he read. "Send Danby and companion
in scout car ahead, to report to me for special duty. Congratulations on
his splendid work, reported to me fully by General Bean."

"That is the sort of thing that makes it worth while to do good work,"
he said. "I think we saved General Harkness from an embarrassing
position this morning, and it is good to think that he appreciates what
we were able to do. Get along, now, Jack, and report to headquarters
just as soon as you can."

There was now no need