The real reason for Great Britain's having a powerful navy applies with exact equality to the United States. Now that Great Britain has proved how great a navy is best for her, we can see at once how great a navy is best for us. That is--since Great Britain and the United States are the wealthiest countries in the world, and since the probability of war between any two countries is least when their navies are equal in power--the maximum good would be attained by making the United States navy exactly equal to the British navy. CHAPTER IV NAVAL PREPAREDNESS In a preceding chapter I endeavored to show why it is that the necessities of the naval defense of a country have caused the gradual development of different types of vessels, each having its distinctive work. If those different types operated in separate localities they would lose that mutual support which it is the aim of organization to secure, and each separate group could be destroyed in turn by the combined groups of an enemy. For this reason, the types or groups are combined in one large fleet, and an admiral is placed in command. The command of a fleet is the highest effort of the naval art. Its success in time of war demands in the admiral himself a high order of mind and nerve and body; and it demands in all the personnel, from the highest to the lowest, such a measure of trained ability and character that each shall be able to discharge with skill and courage the duties of his station. In order that the material fleet shall be efficient as a whole, each material unit must be efficient as a unit. Each ship must be materially sound; each pump, valve, cylinder, gun, carriage, torpedo, and individual appliance, no matter how small, must be in condition to perform its expected task. The complexity of a fleet baffles any mental effort, by even those most familiar with it, to grasp it fully. Each dreadnaught, battle cruiser, destroyer, submarine, collier, tender, hospital ship, scout, supply ship, and what-not, is a machine in itself, and is filled with scores--in some cases, hundreds--of highly specialized machines, operated by steam, oil, air, electricity, and water. A superdreadnaught is a machine which, including the machines inside of her, costs $15,000,000; a battle cruiser more.