“That’s the work of the wind,” thought Jimmy. “Shifting to the southwest, it has blown me to the northeast of the line. I’ll move over to the right a little.” He kicked his rudder bar, shoved his stick over ever so slightly, and sat listening. “Dot dah, dot dah, dot dah,” sang the ear phones, but presently the signal changed. “Dah, dah, dah, dah, dah,” it went. He was back on the course. “Gee, but I’m glad I’m flying in the year 1929, and not half a dozen years ago,” thought Jimmy. “I’d soon be way off my course and never know the difference if I didn’t have this radio set. I tell you, a compass doesn’t help much when there’s a cross-wind. Half a dozen years ago, before there were any radio beacons, I’d have had to make this trip by dead reckoning, and I’d probably have landed in Connecticut, or Massachusetts, or any old place except Long Island.” He flew on, listening carefully to the buzz of the radio beacon, and intent upon his task. He was pleased to know that his friend, the forecaster, had taken so much trouble on his account. He would have been still more pleased could he have known to what extent the weather man was laboring in his behalf. For after Jimmy left the Cleveland Airport, Beverly Graham sat down at his desk and devoted himself to doing all that he could to get Jimmy through in safety. Suddenly Jimmy heard a sharp signal, sounding above the dull buzz of the directional beacon. A smile of satisfaction flitted over Jimmy’s face. “I’m right over Brookville,” he muttered. Quickly he glanced at his clock, then made a rapid calculation. “I’m right on the line and right where I ought to be at this minute,” he thought. “I’m making almost exactly 150 miles an hour.” What he had heard was a marker beacon. At intervals along the airway, radio signals are sent up vertically, just as they are sent horizontally from the radio beacons at Cleveland, Bellefonte, and Hadley Field. These vertical radio beams are audible only for the brief spaces of time it takes a plane to sweep over the stations sending them. The present signal was gone almost as soon as Jimmy heard it, but it gave him a world of information and assurance. It told him, not merely that he was on the line, which he already knew, but it also told him the exact point on that line which he had reached. He soared onward with increased confidence. Intently he watched his instrument board. From time to time the radio beacon warned him that he was being blown from the direct line, and he nosed his plane back to the path. Everything seemed to be going well. His clock told him that he should be nearing Bellefonte, the half-way point between Cleveland and Hadley Field. Also, the radio signals were now so much more powerful that he knew he must be close to the beacon emitting them.