This, it may be explained, is gliding downward from a height with the engine shut off. Aeroplanists often do it, and Tom was no novice at the art.
They shot downward with less speed now, for the young inventor had thrown up his headplanes to act as a sort of brake. Then, a little later they made a good landing in a field near a small house, in a rather lonely stretch of country, about ten miles from Shopton, where Tom lived.
"Now to see what the trouble is," remarked our hero, as he climbed out of his seat and began looking over the engine. He poked in among the numerous cogs, wheels and levers, and finally uttered an exclamation.
"Find it?" asked Ned.
"Yes, it's in the magneto. All the platinum bearings and contact surfaces have fused and crystallized. I never saw such poor platinum as I've been getting lately, and I pay the highest prices for it, too. The trouble is that the supply of platinum is giving out, and they'll have to find a substitute I guess."
"Can't we go home in her?" asked Ned.
"I'm afraid not. I've got to put in new platinum bearings and contacts before she'll spark. I only wish I could get hold of some of the better kind of metal."
The magneto of an aeroplane performs a service similar to one in an automobile. It provides the spark that explodes the charge of gas in the cylinders, and platinum is a metal, more valuable now than gold, much used in the delicate parts of the magneto.
"Well, I guess it's walk for ours," said Ned ruefully.
"I'm afraid so," went on Tom. "If I only had some platinum, I could—"