check valves. Suctions are located in forward and after ends. of the engine room and fire room. The compartment forward of the fire room has one suction. There is a six-inch suction and piping in the engine room to the circulating pump, which can be used in freeing the engine room of large quantities of water. There is a 2-inch steam ejector in the fire room with a suction in the bilge, and one in the crew's quarters aft with a suction on the platform deck. Other compartments are fitted with stand pipes with connections on the platform deck for the standard Navy handy-billy pump. FIRE MAIN. The fire main consists of 221⁄2-inch galvanized piping which runs directly under the main deck from frame No. 31 to No. 95. It connects to two 7-inch X 7-inch X 12-inch vertical, double-acting, simplex Worthington Blake-Knowles fire and bilge pumps located in the engine room.. Cut-out valves divide the system into a forward and an after section. Risers with connections lead from the fire main so that every point in the vessel may be reached by a 50-foot length of hose. Water for the flushing system is taken off the fire main. GALLEY. The galley installation consists of one two-section oil-burning range, fitted to use either air or steam for atomization, two steam aluminum kettles of twenty gallons each, one coffee urn of twenty gallons capacity, a dresser with sink and steamheating pipe, and a fuel oil tank with a hand-fuel oil supply pump taking a suction from the fuel oil manifold in the forward part of the fire room. 1 Main turbine, reduction gear, Kingsbury thrust and exhaust 2 Shafting, including casings, sleeves and coupling bolts.... Weights. 21,394 5,954 1,294 9-10 Boilers and boiler fittings complete, including burners.. 50,488 19 Tools, stores and spare parts (not installed)... 20 Miscellaneous machinery-Air compressor and tanks and 2,417 3,005 74 8,549 2,175 Piping, lagging and fitting on auxiliary condenser lines........... 1,229 Total, pounds .208,9074 ELECTRICAL INSTALLATION. There are two General Electric 10 kilowatt turbo generators. direct connected, 125 volts, 4,000 revolutions per minute. The turbines are designed to operate on full boiler pressure and 10 pounds back pressure. The main switchboard, distribution panel, and battery charging panel are combined and are located near the generating sets in the engine room. There are three lighting circuits general, battle and auxiliary. The wiring is Navy Standard. The auxiliary lighting circuit is arranged to cut in automatically when the quick-closing stop valves are thrown. This circuit is energized by two sets of storage batteries, 32 volts, 210 ampère hour capacity. The auxiliary lights are distributed in parts of the ship where light is essential in case of emergency. There are two %-horsepower, 32-volt, ventilating sets for forced ventilation. They are operated normally on the 125-volt circuit through a series resistance, which is automatically cut out by relays when it is desired to run on auxiliary circuit. The radio installation consists of a 1 kilowatt Navy Standard telegraph set and a radio telephone set. Both sets can be controlled from the pilot house. The radio telegraph motor generator is located in the engine room. The telephone is energized from the battery circuit. In addition to the counter gear, there is an electric tachometer, mounted alongside the gauge board, which indicates the number of revolutions the propeller shaft is actually making and the direction of rotation. The tachometer magneto is driven from a split gear on the propeller shaft. Reports which have been received concerning the operations of Eagles 1, 2 and 3 which have been doing duty in the White Sea state that those boats have been doing despatch duty between Murmansk and Archangel, each cruising about 8,000 miles at a standard speed of 14 knots in waters full of floating ice, that they have satisfactorily carried out target practice at a speed of 17 knots, and that they are satisfactory in all respects. REMARKS ON THE PROBLEM OF IMPACT. The problem of impact contains many elusive points. In an average text book it covers but a few pages of space, and we are started off with the following hazy notions: 1. We know something about the coefficient of restitution. 2. Carnot's theorem is given to us as a firm basis for solution of almost any problem: kinetic energy, lost in impact, is equal to that, due to lost velocity. This, as a rule, is not so at all, in ordinary problems of life, although, in itself, from the standpoint of theory, Carnot's theorem is, of course, quite correct. 3. We also retain, too well, as a rule, that in impact something is just twice the value it would have if the force were applied gradually. Whether this something is the stress or the. deflection, and what the other conditions of the problem are, does not matter; but the ratio itself, twice, survives longer, generally, than any other notion acquired in the school; and we are actually apt to hypnotize ourselves into the belief that a weight of 2 pounds if dropped on the floor from the height, say, of 5 feet, will produce the force of blow exactly equivalent to a 4-pound weight gently placed on the said floor. Anyone who wishes to be cured from this absurd notion is invited to experiment by placing, and then dropping, the weight on his toes; he will see the point at once. In general, the idea of force of blow, and the rather closely associated one, of work of blow, mean absolutely nothing; in themselves, such things do not exist. It is like that other commonplace question one is often asked, in reference to a wound music-box spring: how many horsepower is there in such a spring? There can positively be no answer to such a |