It is however in these wider operations, which embrace a whole theatre of war, and in a maritime contest may cover a large portion of the globe, that the teachings of history have a more evident and permanent value, because the conditions remain more permanent. The theatre of war may be larger or smaller, its difficulties more or less pronounced, the contending armies more or less great, the necessary movements more or less easy, but these are simply differences of scale, of degree, not of kind. As a wilderness gives place to civilization, as means of communication multiply, as roads are opened, rivers bridged, food-resources increased, the operations of war become easier, more rapid, more extensive; but the principles to which they must be conformed remain the same. When the march on foot was replaced by carrying troops in coaches, when the latter in turn gave place to railroads, the scale of distances was increased, or, if you will, the scale of time diminished; but the principles which dictated the point at which the army should be concentrated, the direction in which it should move, the part of the enemy's position which it should assail, the protection of communications, were not altered. So, on the sea, the advance from the galley timidly creeping from port to port to the sailing-ship launching out boldly to the ends of the earth, and from the latter to the steamship of our own time, has increased the scope and the rapidity of naval operations without necessarily changing the principles which should direct them; and the speech of Hermocrates twenty-three hundred years ago, before quoted, contained a correct strategic plan, which is as applicable in its principles now as it was then. Before hostile armies or fleets are brought into con_tact_ (a word which perhaps better than any other indicates the dividing line between tactics and strategy), there are a number of questions to be decided, covering the whole plan of operations throughout the theatre of war. Among these are the proper function of the navy in the war; its true objective; the point or points upon which it should be concentrated; the establishment of depots of coal and supplies; the maintenance of communications between these depots and the home base; the military value of commerce-destroying as a decisive or a secondary operation of war; the system upon which commerce-destroying can be most efficiently conducted, whether by scattered cruisers or by holding in force some vital centre through which commercial shipping must pass. All these are strategic questions, and upon all these history has a great deal to say. There has been of late a valuable discussion in English naval circles as to the comparative merits of the policies of two great English admirals, Lord Howe and Lord St. Vincent, in the disposition of the English navy when at war with France. The question is purely strategic, and is not of mere historical interest; it is of vital importance now, and the principles