4. The Bureau of Ordnance, which has charge of the manufacture of guns and ammunition, also of torpedo stations and magazines. 5. The Bureau of Construction and Repair, which is charged with the building and repair of small boats and of the hulls of ships, and attends to the purchase of turrets and armor. 6. The Bureau of Steam Engineering, which directs the building and repairing of machinery in any way connected with the ships. 7. The Bureau of Medicine and Surgery, which designs, erects, and maintains naval hospitals and superintends their management. 8. The Bureau of Supplies and Accounts, which is responsible for the purchase and supply of all provisions and stores, and of the accounts relating to the same. Each of these bureaus is presided over by an officer of skill and experience, who, while he holds the office, has the rank of commodore. The United States has navy yards at Portsmouth, New Hampshire; Boston, Massachusetts; Brooklyn, New York; League Island, Pennsylvania; Norfolk, Virginia; Washington, District of Columbia; and Mare Island, California. At these navy yards ships are overhauled and repaired, machinery is adjusted and renewed, and stores of all kinds are provided. Here, too, on the receiving ships, the recruits are received and instructed. There are naval stations at Newport, Rhode Island; New London, Connecticut; Port Royal, South Carolina; Key West and Pensacola, Florida; and Puget Sound, Washington. At Indian Head, Maryland, is the naval proving-ground for the test of armor and guns. The Naval Observatory is at Washington, and was at first merely a depot for naval charts and instruments. In 1898, the highest officer in the American navy was the rear admiral. The other officers in their order, ranking downward, were commodores, captains, commanders, lieutenant commanders, lieutenants, lieutenants junior grade, and ensigns. All these are known as officers of the line. At the close of the year there were seven rear admirals, ten commodores, forty-one captains, and eighty-five commanders. The rank of rear admiral is equal to that of major general in the army. A commodore is equal to a brigadier general; a captain in the navy ranks with a colonel in the army; a commander ranks with a lieutenant colonel; and a lieutenant in the navy is equal to a captain in the army. The law provides that when an officer reaches the age of sixty-two years he must be retired from active service. One who has been disabled in the service, or who has served honorably for forty years and requests release, may also be retired. Officers on the retired list receive three-fourths as much pay as when on active duty at sea. Rear Admiral Dewey will be retired on the 26th of December, 1899. In 1898 there were thirty-three rear admirals on the retired lists.