A further cause for this quiet and unusual acceptivity is to be found in the medium in which the Navy works--the sea itself. The sea has ever been a barrier to investigation, and the Navy and the sea are one. Public opinion is land-made, and landsmen have neither time nor inclination to cope with the riddles of the ocean, which to most of us is vague and inimical, the home of risks and discomforts which it is wiser to avoid. Well content to consider her, from a safe distance, as a Sphinx, we are very happy that to others has fallen the perilous lot of patrolling her and very full of gratitude for their courage and success. If the Army, on the contrary, is so much under the microscope, it is largely because it has few or no mysteries. We know the rules. Armies are made up of men like ourselves (only better). They advance as we do, by putting one foot before another, on the solid earth. Their movements are followable, even if we cannot always understand them; daily bulletins are printed in the public Press. But the Navy keeps its secrets. Not only have we no notion where it is, but we should be little the wiser as to its inner purposes if, scanning the illimitable and capricious waves, it should be our fortune to descry here and there a flotilla of its dark grey hulls. Even in harbour most men pointing out a cruiser to their children say "That's a dreadnought"--a state of confusion bred and fostered by the strange, dark, dangerous element in which the Navy has its being. So much for the causes of our odd willingness to forego one of the chief privileges of British birthright, which is to criticise, even to belittling, all that is ours. But there is justification, too, as the state of the sea to-day testifies. Thanks to the Navy there is at this moment hardly an enemy ship at large on the surface of the waters. The Kaiser's darling ironclads are idle as painted ships upon a painted ocean: not even an ocean, a canal. Our troops in millions have crossed to the Continent. We have enough to eat. By what wonders of efficiency and discipline, machinery and co-ordination, this result has been brought about we neither know nor are concerned to enquire. Enough that it is. But when it comes to _personnel_, curiosity is legitimate; and this collection of portraits and brief biographies has been prepared in the belief that very many of those whose lives have been rendered secure by these efforts of the Navy would like to see what manner of men are in control of our safeguards. This is the heyday of the picture, and here are the pictures of our leading sailors--the commanders who stand between us and the foe and keep the foe at bay.