red so quickly, and the retreat had been made so promptly,
thanks to Snake's vigilance, that aside from a little irritation of
their mouths and throats the attackers were not injured. The
irritation soon passed away and was about gone when they neared the
ranch.

"They were just teasing us that time," decided Snake. "The next time
they'll shoot some real nasty gas at us."

"And that's the time we'll be ready with the masks," declared Nort.

Bud Merkel was as excited as either of his cousins when he heard the
news. He declared no better plan could be devised than going against
the unknown cave dwellers with gas masks and a telephone message was
soon on the way, asking the commander of the Los Pompan branch of the
American Legion for the loan of as many of the protectors as were
needed.

In due time word came back that the Dot and Dash ranchers were quite
welcome to the masks. Snake and Kid, as experts in their use, and as
judges of the best ones to bring back, were sent as a committee into
town to get the life-saving apparatus.

It was next day, when the gas masks had been tried on by the cowboys
who were to use them, and plans were being talked over for a second
attack, that Nort suggested:

"Maybe we ought to try these masks before we use them. They may be
defective in spite of the fact that they look all right."

"Not a bad idea," agreed Bud. "But we haven't any poison gas to try
'em with."

"If we could go in a room filled with ammonia, or some such vapor as
that, we could soon tell if the masks were any good," Dick suggested.

Dr. Taylor was communicated with and agreed to supply from his somewhat
limited laboratory sufficient fumes to make a sure test of the masks.
He came out to the ranch, a small room was set aside for the experiment
and into this vile chamber the men went one at a time, each one wearing
the mask that was designed to protect him in the coming fight.

With the exception of one or two of the affairs, each one was gas proof
and the defective ones were quickly replaced with good ones. So that
in a comparatively short time the avengers were once more ready to make
the attack.

Much the same tactics were observed as on the former occasion. The
horses were left well out of reach of any clouds of vapor that might
float from the ravine, and the guards were instructed to deploy their
reserve cavalry to east or west, according to the direction of the
wind, in case gas was noted coming