At the top and at the bottom of this, were two, pulley blocks with a rope passing around the sheaves a sufficient number of times to provide a three-to-one relation between a 1500-pound weight suspended from the top pulley and the movement of the aeroplane on the track.
The rope, which passes around the pulley at the bottom of the derrick, is carried forward to and around a pulley at the front end of the rail, and thence back to the aeroplane, to which it is attached with a right-angled hook. When everything is ready for an ascension and the operator is in place, the propellers are set to work. When they have reached their maximum revolution and the car begins to feel their propelling force, the weight, usually several bags of sand, is released, the tightened rope shoots through the pulleys and the balanced aeroplane springs forward on its car. By the time it has traveled seventy-five or one hundred feet, the impulse of the falling weight and the lift of the propellers sends it soaring. Thereupon, the hook drops off and the free airship begins its flight.
“We have the plans for the derrick and the track, the pulley blocks, rope and hook,” declared Bud at once. “But we haven’t the little car.”
“Couldn’t we make one?” ventured Lafe.
“Certainly, but hardly in the time we have.”
“I’ve heard of aeroplanes ascending by skidding along over the grass,” suggested the bank clerk.
“But they weren’t in the hands of amateurs. We’d better stick to the rail. I’ve been thinking over this—down there in the freight-house.”
“Did you know the track car wasn’t here?”
“Well, I didn’t see it. Here is the idea. The aeroplane has two light, smooth landing runners or skids. Lumber is cheap. Instead of a track for the wheels we haven’t got, we’ll make two grooves just as long as the proposed track. We’ll stake these out on the ground and set the landing runners in them after we’ve greased the grooves with tallow. The weight, rope and hook will work exactly as if we had a single track—’n possibly better. Anything the matter with that suggestion?”
Lafe was skeptical a few moments while Bud made a sketch of the new device. Then he conceded that he could see no reason why it wouldn’t work.