It happened that the biplane came to a stop close to the girl, who was standing there staring, as though hardly understanding what it all meant. Andy hopped out the first thing even though he happened to be holding the monkey wrench in his hand at the time, having snatched it up in his excitement when he first discovered the threatening peril of the girl.

He had just reached her side, and was starting to speak when a warning shout from Frank, still in his seat aboard the aeroplane, caused Andy to look around.

"The dog! Take care, he's going to attack you!" was what Frank shouted.

Apparently the ugly beast had already recovered from his fright, when it discovered that human beings were aboard the strange airship. He had halted a little distance away, and then, as Andy actually headed toward him, started to meet the newcomer.

There could be no mistaking the evil intentions of the beast, he was of the savage bulldog strain, and from the cut of his mouth it could be seen that just now he meant business. And as Andy could not retreat, with that pretty girl standing there unprotected, he just had to raise his monkey wrench and wait for hostilities to begin.

CHAPTER XVIII

AT THE FOOT OF THE LIBERTY POLE

"Look out!" shouted Frank, who was trying to find some sort of weapon himself, armed with which he could hasten to the aid of his chum.

But Andy kept his senses well about him. Perhaps had he been alone, and there opened a favorable chance whereby he could put a convenient fence between himself and those grim square jaws of the ugly dog, he would have been only too glad to do so. But that was utterly out of the question now. The girl must be defended, come what might.

He fortunately remained fairly cool, which was a good point in his favor. Just then, singular to say, Andy seemed to remember what he had read about what Old Putnam said to his Colonials at the battle of Bunker Hill: "Wait till you can see the whites in their eyes, boys!" He held himself back until he was positive that he could land a blow on that massive head of the prize bulldog.