ed to go aloft after the orders
came detailing them for work in connection with the monster cannon.
Their places were taken by others who were sent for, some being new
fliers who were burning to make a name for themselves.

Besides Tom and Jack, in the picked squadron there were Boughton,
another American, Cerfe and Tierse, two intrepid Frenchmen, and Haught,
an Englishman, who insisted, but with little success, that his name be
pronounced as though spelled "Hoo."

These six were to be depended on to find and destroy the German
cannon--all of them if there were more than one, as was likely. And to
this picked squadron other members would be added as need arose. All six
were skillful fliers, and brave men of the air, as may easily be
guessed. They were to use whatever type of machine they liked best--the
single seaters, the great bombing planes, and, it was even said, one of
the immense Italian fliers. This last was a craft capable of carrying
several men and a quantity of supplies and ammunition.

Very soon, then, Tom Raymond and Jack Parmly were on their way to Paris
again, accompanied by their comrades, and all would soon be engaged in
the difficult and perilous task of finding the new German long-range
cannon.

"I suppose you'll make another attempt to find your father?" suggested
Jack to his chum, as they rode in on the train.

"Indeed I shall, if I have time. I can't understand why I haven't had
some word before this. There are several possible reasons, of course. If
it wasn't that we know he got to Rue Lafayette I'd say his ship had been
sunk 'without a trace,' as the Germans ordered in other cases. But, of
course, he safely reached this side. Then he just seems to have dropped
out of sight, for I can't believe he was killed when the shell from the
big gun hit the house where he had taken lodging. He may have found it
advisable to return home at once, for some reason, and didn't have a
chance to leave any word for me, or send me any message. And perhaps he
hasn't got back to America yet. Then, too, he may be in Germany, a
prisoner."

"Let us hope not," said Jack, softly, and Tom echoed the wish.

Much as he wished he could devote some time to the search for his
father, Tom realized that he was working under military orders, and,
however dear his father was to him, the sacrifice of his personal
affairs must be made. He knew he would only have time to make some brief
inquiries, and then he and Jack must go w