Before was represented by 2112-3, your by 111-211-3, etc. It took
quite a little practice to learn the different combinations. Fred and
Reddy soon became experts, and could flash the signals back and forth at a
great rate.
[Illustration: Fig. 151. The Signal for Letter "B."]
Wigwagging at Night.
At night we used a torch in place of a flag. The torch consisted of a roll
of dried birch bark tied with wire to the end of a staff. It was found
necessary to place another torch on the ground directly in front of the
signaler so as to fix a central point and enable one to determine whether
the moving torch was swung to the left or right. A later improvement was
to use three lanterns, one in each hand and one attached to the waist to
fix the central position. It was quite an advantage to have a lantern in
each hand, for it saved changing over from one to the other when a second
movement followed a first or a first movement a second.
[Illustration: Fig. 152. Wigwagging at Night.]
The Heliograph.
The book that Uncle Ed sent us had in it a description of a heliograph,
that is, an instrument for sending signals with flashes of sunlight.
Although our wigwagging system was good enough for our requirements, yet
we thought it would be more scientific to use the sun instrument, and
besides, the latter could be used for signaling many miles.
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