Frank shot a look upward.
The biplane had not diminished its speed an iota all this while. Puss was attending to his part of the business, leaving all other matters in the care of his well groomed assistant.
Both of them were leaning forward, staring down and backward at the monoplane. Even at that distance Frank could see that their faces were as white as chalk, as though the enormity of what they had done now burst upon them. Perhaps they may even have felt a spasm of relief at that moment, because the sand bag which had been dropped had missed its intended target, thanks to Frank’s ready wit.
Now the monoplane seemed to be pushing forward with more speed than ever, as if bent on making up for lost time. And Frank was rising, too, for he knew he must of necessity find himself above the crown of the mountain, when ready to alight.
“What was that they dropped?” he asked of Andy.
“Looked like a sand bag,” replied the other; “but whatever would they be doing with such a thing in a biplane?”
“That was what I wanted to know,” replied Frank, “when I saw it tied there with a cord; and Puss explained that he and Sandy were not quite heavy enough. Said their experiments had proved the biplane could make faster time with a little more weight!”
“He just lied!” burst out the indignant Andy. “A hundred to one they took that sand bag up with them on purpose to drop it on us if we tried to pass. And look how he kept hovering up there. That gives him away, I tell you!”
“Perhaps he got the idea from hearing how that other sand bag came down on our lumber pile, nearly squashing us while we slept!” observed Frank.
“Well, he only had one, didn’t he?” questioned Andy, showing considerable nervousness; for they were now once more directly under the biplane.