The reconnaissance machines and the bombing planes may do valuable service,--and indeed they invariably do--but it is the "speed scout" that covers itself with glory. The reason is that its career brings it nearer to the "personal combat" of the knights of old than anything in modern warfare. Driving his swift Nieuport scout as a knight would have ridden his charger, the beloved Guynemer went forth to challenge the German fighters,--and other Frenchmen and Englishmen and Americans have followed him. It is a fact beyond all question that this branch of the service has produced some of the most truly unselfish and heroic figures of the whole war. The "speed scout" pilot did not need to be a man deeply versed in military affairs--as for instance the pilot and observer of the reconnaissance machine must be,--but he did need dauntless courage, unfailing nerves of steel, dash and daring and contempt for his own safety. So wherever the "speed scout" has blazed its trail of fire across the sky, there have sprung up the names of men whose heroic deeds have made them the idols of the whole world. Usually they have been very young men--young enough for their ideals to have kept fresh and untarnished from the sordid things of life, and thus they have written their names among the immortals. [Illustration: _Copyright Underwood and Underwood_ A PHOTOGRAPH OF NORTHERN FRANCE TAKEN AT A HEIGHT OF THREE THOUSAND FEET] Less appealing to the imagination, perhaps, but no less vital to the progress of modern warfare, is the slower flying reconnaissance craft. This machine is always a two-seater, and sometimes a three, for at the very minimum it must carry a pilot and an observer, while a gunner is a very convenient third party in case of an attack from enemy scouts. This type of machine is used for photographic work, for artillery "spotting," and for many general service duties over the lines. In the early days of the war it was customary for the photography airplane to be escorted on its mission by a group of fighting machines, who hovered about it and engaged in battle any airplanes of the enemy that might seek to interrupt its important work. But the last year or so have brought many improvements in airplane construction and it has been found possible to build a machine which can not only carry the heavy photographic apparatus and a couple of machine guns, but which can also travel at a good speed and climb fast enough to escape from the anti-aircraft guns. Instead of the rather helpless, clumsy, slow-flying reconnaissance machines of the early part of the war, we now have powerful "aerial dreadnaughts," which no longer need to run away, but can stay and fight it out when they are interrupted in the course of their air duties.