interested now.

"And they learn more than that," Whyn continued. "They talk with
flags."

"Talk with flags! I never heard of flags talking, and I don't believe
it."

"Oh, I don't mean that flags talk," and Whyn laughed outright. "The
scouts use flags for talking to one another when they are some distance
apart; it is called 'signalling.'"

"How do they do it?"

"Well, one boy will stand, say on a hill, while another is somewhere
else, and each has two little flags. They wave these and whichever way
a flag is waved it means a letter. I did know all the letters myself
once, for Douglas taught me. In that way the scouts can talk with one
another as far as they can see. Soldiers send messages that way, so I
understand, and they can warn one another when an enemy is near."

"My, I would like to know that," and Rod gave a deep sigh. "I wonder
if Captain Josh knows anything about it. I am going to ask him,
anyway."

"There are many other things the scouts have to learn," Whyn explained,
"and they are very important."

"What are they?"