There is a great deal of confusion between the terms “airship,” and “flying machine,” and the two words are often considered as meaning the same thing. But while, strictly speaking, neither word in itself has any very definite meaning, it is gradually becoming more general to apply them to two widely different objects. According to this plan, although both names stand for an aerial vessel capable of travelling in the sky by its own motion, an airship is a machine supported in the air by reason of its buoyancy, while a flying machine is kept aloft only by virtue of its onward movement. In other words, part of the construction of an airship consists of a bag or balloon, filled with gas or hot air, which causes the whole to rise and maintain its position in the air. This balloon part is quite independent of the machinery which drives the airship forward, and indeed if the engine ceases working, the vessel becomes nothing more than an ordinary balloon in its nature, and will behave like one. An airship, therefore, is in principle an apparatus lighter than air. A flying machine, on the contrary, is heavier than air, and maintains its position aloft merely by the power it obtains from its engines, assisted by its special construction. The inventors of flying machines take as their analogy the flight of birds. Birds are creatures heavier than air, which yet manage to rise and fly by reason of the strength and construction of their wings. In the same way the heavy flying machine essays to fly by the power of its machinery. And, as a bird aloft, if its wings became disabled, would instantly drop towards earth, so a flying machine would immediately commence to fall if its engine stopped or ceased to move with sufficient power. The airship and the flying machine, therefore, may be regarded as rival aerial vessels, and their inventors and advocates, sometimes known as “lighter-than-air-ites” and “heavier-than-air-ites,” though both working for the same end, are endeavouring to accomplish their aim by widely different methods. Up to the present day the airship--to which we will first turn our attention--has been much more largely and successfully experimented with than the flying machine. It is, however, the opinion of many, including the great authority Sir Hiram Maxim, that in the future the flying machine will become the more important invention of the two. “In all Nature,” says Sir Hiram, “we do not find a single balloon. All Nature’s flying machines are heavier than air.” And from this he argues that, as Nature is ever our best guide and example, a flying machine heavier than air will be in the end most likely to succeed.