It is doubtful whether aviation will entirely do away with fighting on land and sea, but it is very obvious that either fleet or army of one belligerent nation, at the mercy of the air fleet of another nation, will be in a very helpless position. Should the warfare in the air be indecisive, were such a condition within the realm of reasonable argument, it might be possible for the fleet or army to be brought into action with advantage, but even this is doubtful. As regards our own nation, before 1926, the Royal Naval Air Service will be the largest and most important service in Great Britain. Possibly there will be a single Air Service, and before ten years will have elapsed it will be the most important of all the British services, and will be composed both of aeroplanes and airships. The only other form of aircraft, the seaplane, being too slow, too clumsy, and too costly, will long ago have been abandoned. PEACE AND WAR USES OF AIRCRAFT Before we enter upon the discussion which is the subject of this paragraph we wish to guard ourselves against one misconception. It is possible that readers of this chapter may already have come to the conclusion that it is possible to develop aircraft for one purpose, and one purpose only: that is, either for war or for commerce; and impossible to develop them for both. This would be an entirely erroneous idea. It is true that we have already laid stress upon the fact that there is a very imminent danger that aircraft may be developed too greatly for war purposes to the detriment of others, but provided that the necessary precautions are taken, there is yet ample time for the commerce-carrying machine to be developed at the same time and in the same manner as the war machine. Within a very short time we may find that the Super-Zeppelin of the air will have entirely replaced not only the Dreadnought of the sea, but also the giant passenger liners. Both the war and the peace craft will be considerably larger in size than the 1916 type; the balloon portion of the Zeppelin will have trebled itself in size; it will be, if anything, of greater length and of slimmer formation, while the covering will be composed of some light but durable metal, such as aluminium, to prevent the possibility of explosion of gas caused by the firing of the guns. The narrow gondola beneath will be wider, and will mount several guns of 4.7-inch or larger caliber: for although the Zeppelin of the future will be a much more stable and airworthy craft, by reason of its lateral stability it will never be possible to fire a gun of any size from either bow or stern of an airship or a Zeppelin, without bringing the whole craft canting over, and possibly breaking its back. Thus, all Super-Zeppelins of the future will be heavily armed amidships, that is to say, where the proportion of strain on the craft is least felt. The passenger-carrying variety will differ very slightly from the