“Never might happen again in twenty years,” said Jack, as if that feature of the near tragedy affected him most of all. “With all this wide space all around us, just to think of two airships heading straight at each other in a fog—who says now we’re not watched over by a special Providence?”

“You said it buddy,” Perk agreed. “That sure was a time when that muffler paid a big interest on its cost an’ I kinder guess saved our lives in the bargain. It pays to advertise an’ also to pick up the newest fixin’s along the line o’ aviation discoveries an’ inventions.”

“Just so Perk. If our engine had kept thundering away right along we might not have been warned in time to get out of the road and let that stunt-flying air mail pilot squeeze past. He ought to be reported for hustling along like that in such a thick soup; but since we’re still alive and kicking, I reckon we’ll just have to let it drop at that.”

“Mebbe you’re right there, Jack old bean—strikes me we were hittin’ it up like hot cakes in the bargain an’ not so innocent after all. I’m a’wonderin’ if he got wind o’ the close call he had—must have lamped our lights as we ducked and went down like a bullet or the stick o’ a rocket that’d exploded up near the stars. Shucks! I’d jest like to meet up with that guy sometime an’ ask him what his feelin’ was—bet you he was as scart as we felt when he whizzed right over our heads.”

“It might be the part of wisdom to climb to a higher level now, partner,” hinted Jack. “Unless I miss my guess that chap was dropping, as if he’d come down from the upper regions, which gives me an idea he knew where he was and had been keeping a big ceiling so as to avoid butting into some mountain peak.”

“Here goes then,” and with the words Perk commenced to climb, the new ship being so constructed as to be a great improvement over the old type of plane, able to ascend at a steep angle without any of those formerly necessary laborious spirals.

At the height of four thousand feet he again leveled off and kept to the course Jack had marked out. Perhaps they were over some air mail line with its friendly flashing beacons winking far below; but that deadly wall of fog lying under their keel effectually prevented them from taking advantage of any such guide posts along the way; nor would it have availed them greatly could they have dropped down to within a few hundred feet of the earth, for even at such a distance it must have been utterly out of the question for the keenest vision to have picked up a beacon or even detect its flash because of the curtain that fairly smothered them on all sides, above and below.

They no longer conversed, even Perk understanding how serious their condition must be and holding his usually ready tongue in check, while Jack took it out in tense thinking, watching the various dials and figuring just which way they would be going in case of drift.

So half an hour crept by, with no change whatever in the conditions by which they were surrounded. It was now growing most unbearable, so monotonous, so very tiresome. A heavy fog is hard enough to bear at any time but when it stretches along hour after hour, without the slightest sign of any diminuation, it is bound to get on the stoutest nerves and produce symptoms bordering on a panic.

“Perhaps we might find some relief if we kept going up,” suggested Jack after some time had passed. “It sort of stifles me to keep in such a thick mess as this, growing worse all the while.”