d, even if standing on
the earth a mile below their plane.

It was arranged for all three of them, and could be removed from the
head when no communication was desired. In the beginning they were not in
the mood to make use of this contrivance, which, however, would
undoubtedly be welcome later on, when they would be passing over the
apparently limitless sea and the monotony had begun to wear upon their
nerves. Then conversation might relieve the tension.

It was Jack who presently called out:

"I can see lights below us. Do you think we've crossed the Channel,
Lieutenant?"

"Yes, that's the English shore, and doubtless Dover lies directly below
us, although we're at such a height that it's impossible to make sure."

"What's the idea of keeping so high, Lieutenant?" continued Jack.

"Simply to avoid collision with any of the coast guard fliers, who might
take us for Huns meaning to attack London again after a long break. But
Jack, I'm going to ask a favor of you."

"Go to it then!" called out the other, who was plainly "on edge" with
excitement over the wonderful fact that they were at last on their way.

"Drop that formality from this time on," said Beverly earnestly.
"Forget that I happen to rank you, for I'm sure your commissions are
only delayed in the coming. From now on let it be either plain Colin,
or if you prefer, Beverly. We're three chums in a boat--a ship of the
air, to be exact--and all ranking on a level. You'll agree to that,
won't you, Jack?"

"You bet I will, Colin, and it's just like you to propose it!" cried the
pleased Jack.

After that they fell silent again, though now and then Jack, who was
making good use of the night-glasses, announced that they seemed to be
passing over some city.

Tom had studied their intended course so thoroughly that he was able to
tell with more or less accuracy what some of those places were. In so
doing he always kept in mind the probable speed at which the big plane
was traveling.

They had veered a little, and would not come anywhere near Liverpool or
Dublin, as Jack had suspected might be the case until he looked over the
chart Tom had marked. On the contrary, their new course would carry them
over the south of England, and just cut across the lower part of Ireland;
indeed, the latter might have been skipped entirely with profit to
themselves in miles gained, only it seemed natural they should want to
keep in touch with land just as long as possible.