By the time Mr. Graham reached the aërodrome in his automobile, Frank and Phil had arrived at the southern end of their flight and turned for their return. They had not been running at top speed and were not over twenty-five miles from home. This was partly due to the fact that they had been climbing to the two thousand foot level.
When they came about, carelessly neglecting to note their precise compass bearings, they were in a position to make a rapid glide. This for a few moments they did, reaching a speed of sixty-two miles an hour for a short time. Then they discovered that they were not sure of their course.
“The trouble was,” explained Phil later to his mother, “that you can’t tell anything about your real movements in an airship when you are flying in a heavy wind and have no landmarks. You’ve got to remember that you don’t feel the wind at all—except that caused by your own flight. In a heavy wind, you move with it; the airship vessel is buried in the fluid of the wind, and moves with it, just as a submarine in a deep river wouldn’t feel the current. It would be a part of it.”
“I’d think you’d tack just like you do in a sailboat,” suggested his mother.
“That’s what every one seems to think,” Phil explained, “but you can’t. You are carried away just as rapidly as if you were directly in the teeth of the wind. The best way is to head right up in the wind. If your engine is stronger than the wind, you’ll advance; if it isn’t, you’ll go back.”
“I hope this cures you of your venturesome ideas,” commented his mother earnestly.
“Not at all,” answered her son. “It gives us just the experience we need. We were over the trees when Frank tried to tack. He drifted back more than he moved sideways. But we know now.”
This conversation occurred the next day. That evening, Mrs. Ewing did not become alarmed until a late hour. Then, in her concern over Phil’s failure to return home, she telephoned to the Graham home. Mrs. Graham could only tell her what Old Dick had reported; that Mr. Graham had gone to the aërodrome and failed to get any information; that her husband had hastened back and telegraphed to the authorities of several towns on the probable course of the boys and was now, with two friends, scouring the country roads to the south.
At two o’clock Mr. Graham returned assuring his wife and Phil’s mother that the boys were undoubtedly all right. For the next two hours Mr. Graham sat in the office of the Herald and then, no word having been received of the missing boys, he drove home for breakfast and a renewed search.