It is merely a phase in submarine warfare. At present a submarine dare not fire too near its victim lest it be involved in the common destruction. That, however, is likely enough to be guarded against in future construction, and the prospects of the early future is one of more importance for submarines rather than less. They are bound to become larger and larger, their radius increasing with the size. Coincidently with this we may expect to see the birth of small submarines designed to attack big ones: some new variant of the swordfish and the whale. VI. NAVAL AVIATION. The aeroplane idea is so old that we find it in Greek mythology, and it is consequently of unknown antiquity. Hundreds of years before Christ there were hoary old legends of Dædalus and Icarus, who made wings for themselves and flew. Icarus flew too high, the sun melted his wings, with the result that there happened to him what happens about once a week to aviators to-day, he fell and died. Contemporary with these legends, are legends of floating rocks which spurted out fire--stories which sounded inestimably silly till steamships came along. We may imagine prophets able to look ahead[39] and to invest their day with visions of the future. Equally we can discard prophets and imagine a civilisation long since dead which knew all about flying and steamers, and survives in legends only. [Illustration: _Photo_] [“_Topical._” BRITISH NAVY SEAPLANE.] The latter alternative is really the more reasonable of the two. While imagination can do a very great deal and exaggerate to any extent, it must have a base to work on. It is easier to believe in some long gone and extinct civilisation which destroyed itself in the air, than to believe that pure imagination accounts for the flying stories of long ago. Africa is full of traces of vast cities older than any history, telling of past civilisations of which nothing is or ever will be known. Also there is practically no known age in which anything but the motive power stood between aeroplane theories and their realisation. In support of the theory that men flew before to-day there is the following:--Somewhere about the year 1100, that is to say, back in the reign of King Stephen, a French historian relates the appearance of “as it were, a ship, in the air over London.” It anchored, and the citizens of London got hold of the anchor. The airship sent a man down to free it, and the citizens of London caught him and drowned him in the river. The rest of the aviators then cut the rope and sailed away. This incident is mentioned so baldly and casually and so much mixed up with ordinary petty chat of the era (chat which proves to have been quite true), that it takes far more faith to accept it as “pure lies” than to accept it as fact more or less.