"Bless my soul, you are right," he exclaimed, angrily, "the little creature eluded me. Oh, dear, this is a bitter day for science. I was in such a hurry to pop my specimen into the bottle that I held him carelessly and he evidently hopped away. Oh, this is a terrible, an irreparable, loss."
Although the boys tried to comfort him they could not. He seemed overcome by grief.
"Cheer up," said Billy at length, "remember there is always the fur-bearing pollywog to be captured."
"Ah, yes," agreed the professor, "but a bug in the hand is worth two in the air."
As they talked, there suddenly came a loud explosion from the engine and two of the cylinders went out of commission. The speed of the aeroplane at once decreased and she began to drop.
The dismay of the boys may be imagined. They were several miles from the camp and below them was nothing but the desolate expanse of the snow wastes that lay at the foot of the barrier range.
"Shall we have to go down?" asked Billy.
"Nothing else to do," said Frank with a grave face, "there's something wrong with the engine and we can't repair it up here. If we were not in this rarified atmosphere we could fly on the cylinders that are firing all right, but this atmosphere would not support us."
"Do you think it is anything serious?" asked the professor.
"I can't tell yet," was the grave reply, "that explosion sounded like a back-fire and that may be all that's the matter. In such a case we can drain the crank case and put in fresh oil; for if it was really a back-fire it was most likely caused by 'flooding.'"