It will be seen, therefore, that these two comrades although quiet and studious came honestly by their adventurous spirit, and also the desire to be of service to their country.

Of course, like all beginners both of the boys had passed through a number of rather thrilling experiences while learning how to manipulate the motors of their airplanes alone. At first an instructor had always accompanied them. They also flew at a low altitude, and by slow degrees advanced along the path of knowledge until finally each was allowed to go up alone.

Once Jack landed with such force that his plane was badly damaged, and he himself had to lay off from work several days because of sundry bruises and contusions received in the tumble.

Then, on another occasion, something happened to Tom’s engine when he was trying his first ascent to a height of a thousand feet or more. When he found that it suddenly refused to obey his bidding Tom felt a spasm of alarm, but he did not lose his head, fortunately.

He started to volplane down, though afraid that his landing would be of a nature to bring about a terrible smash. However, nothing so serious as that occurred, for when two-thirds of the way to the ground his engine began to work again, in response to his eager appeal; and after all he was able to continue his flight.

At present they had both reached a stage in their education that allowed considerable latitude in further ventures. And Tom was now about to undertake a feat that would stamp him as being a genuine aviator capable of attempting extended flights.

Tom had now commenced to fly upward. The little airplane had its nose pointed toward the fleecy clouds floating high in the air above him. Up, and still up the airplane mounted in dizzying spirals. The machine was a good one of modern build, suited for the general work of a novice, still learning how to control his craft alone.

Later on, Tom would discover that the necessities of modern warfare have compelled the cunning artificers of France and Germany and Great Britain to invent a variety of airplanes, each intended for a special purpose. But that was a page in the young fellow’s career not yet turned.

Presently the airplane was almost like a dot in the heavens. Indeed, with the naked eye it was hard to distinguish it from a flying bird. Now and again it temporarily disappeared entirely amidst the white clouds that lay scattered across the sky, to Jack’s eyes resembling marching battalions hurrying to get in battle formation.

Jack, equipped with his powerful glasses, could easily follow the course of his chum. Just as he had said, he did not leave the spot for a minute, but kept faithful watch and ward. He was as deeply interested in the carrying out of Tom’s latest venture as though he himself were the one to profit through its successful issue.