The Sky-Bird fairly cut the air like a knife, and the roar of propeller, wind, and engine was so great that our friends found conversation out of the question except by shouting in one another's ears.  Poor Grandpa cowered in the farthest corner of the cabin, peeping out from behind one of the hammocks, as meek as a kitten, his tail crooking uneasily.  But finding that the strange noises did him no harm, he presently came out and took up a position where he could look through the glass-floor window at the fleeting country below.