"On the practicability of covering a small extent of coast by cruising in front of it--or, in other words, the possibility of anticipating an enemy's operations, discovering the object of movements of which we get no glimpse and hear no tidings, and seeing the impress of his footsteps on the surface of the ocean--it may be well to consult experience." The naval power of Spain under Philip II. was almost unlimited. With the treasures of India and America at his command, the fitting out of a fleet of one hundred and fifty or two hundred sail, to invade another country, was no very gigantic operation. Nevertheless, this naval force was of but little avail as a coast defence. Its efficiency for this purpose was well tested in 1596. England and Holland attacked Cadiz with a combined fleet of one hundred and seventy ships, which entered the Bay of Cadiz without, on its approach to their coast, being once seen by the Spanish navy. This same squadron, on its return to England, passed along a great portion of the Spanish coast without ever meeting with the slightest opposition from the innumerable Spanish floating defences. In 1744, a French fleet of twenty ships, and a land force of twenty-two thousand men, sailed from Brest to the English coast, without meeting with any opposition from the superior British fleet which had been sent out, under Sir John Norris, on purpose to intercept them. The landing of the troops was prevented by a storm, which drove the fleet back upon the coast of France to seek shelter. In 1755, a French fleet of twenty-five sail of the line, and many smaller vessels, sailed from Brest for America. Nine of these soon afterwards returned to France, and the others proceeded to the gulf of St. Lawrence. An English fleet of seventeen sail of the line and some frigates had been sent out to intercept them; but the two fleets passed each other in a thick fog, and all the French vessels except two reached Quebec in safety. In 1759, a French fleet, blockaded in the port of Dunkirk by a British force under Commodore Bogs, seizing upon a favorable opportunity, escaped from the enemy, attacked the coast of Scotland, made a descent upon Carrickfergus, and cruised about till February, 1760, without meeting a single British vessel, although sixty-one ships of the line were then stationed upon the coasts of England and France, and several of these were actually in pursuit.