Where the prevailing wing material had formerly been wood and fabric, tests were now being made to prove the worth of all-metal construction. For new purposes the old-time metallic standbys were found unusable. Light metals crystallized and snapped into brittle pieces. The old strong metals possessed of endurance were too heavy for aircraft. A new metal, light as aluminum and strong as steel, must be produced.
And so the experimenting and testing went on.
As Hal Dane became familiar with some of the scientific revolution and evolution going on at the huge Wiljohn Works, he caught again something of the high splendid vision of following the river of the wind on a great exploration. If ever he were to go as sky viking, here in this vast plant were being riveted and welded aircraft suitable to bear him on that journey.
CHAPTER XIV
DOWN THROUGH THE AIR
With wire braces screaming, a plane shot downward a thousand feet and the pilot struggled to bring his ship out of the left spin.
The pilot was Hal Dane. He had been with the Wiljohn Works nearly a year now. In that time he had participated in some marvelous experiments, tried out in the hope of furthering the safety of aviation.
A room painted black, strung with wires, some bats turned loose in it, and doors and windows closed to darken it totally—this might seem childish dabbling when thought of in connection with the modern science of aviation. Yet it was a test tried out with a very real purpose. Outside of that room men waited at ear-phones connected electrically with those wires so that the least flutter of a bat’s wing against a wire would be indicated. The bats flew madly round and round the room, but never so much as touched one of the many wires. From this experiment scientists contended that bats flying in the air put out some sound and get an echo from that sound when it vibrates near an object. Not so far and foolish a leap from bats to aviation after all! For if a human flyer of the air could devise a ship that put out a sound and got an echo when it approached an object, it would help solve the problem of landing in the dark and of flying in fogs.
Fog, the heavy, silent, dreaded enemy of every aviator! At the Wiljohn Works continuous experimentation went on to help solve the dangers of fog flying. An electrical instrument to measure distance from the ground in tens of feet would help an aviator trying to land in the dark. A mechanical eye to see through the fog was a crying need. Work was being pushed along both of these lines.
Another and very different type of experimentation was the testing of the wings and shapes of aircraft in connection with their air resistance.
The tests for great altitude, however, thrilled Hal Dane more than anything else. Through all this present labor and study, the call of the river of the winds still lured him. And to ride the currents of the air rivers at their swiftest, one must be able to withstand the velocities and the pressure of the air heights. The fearful cold of high altitudes unbalanced ships with heavy coatings of ice, clogged instruments and air indicator tubes with snow. Wiljohn men were pushing experiments for such flying. Already a spread of emulsions on the wings had been found to reduce the ice danger. But for real success, aviators must learn to wholly master the air heights.