"Fourth, in the event of sea-water entering the boat, through leaks caused by external explosion of submarine mines, etc., the personnel cannot be asphyxiated by the formation of chlorine gas.

"Fifth, its mechanical structure makes it capable of resisting shocks, rough treatment and concussion from nearby external explosion of submarine mines and bombs.

"Sixth, it is impossible to buckle or distort the plates by rapid charge or discharge.

"Seventh, the active materials do not shed off with use.

"Eighth, the capacity does not diminish with use until the life of the battery is nearly exhausted.

"Ninth, it does not require dismantling to remove sediment. “Tenth, it has a longer life under any given conditions than any other available battery.

"Eleventh, the individual cells are comparatively light, and may be easily handled if necessary.

"Twelfth, an excess emergency capacity may be stored by prolonged overcharge.

"Thirteenth, the plates are not injured by standing discharged in the electrolyte for any length of time.

"Fourteenth, it is unnecessary to remove plates or electrolyte when a boat is laid up or put in reserve.

"Fifteenth, no hydrometer readings are necessary.

"Sixteenth, it is not necessary to carry a supply of electrolyte. "Seventeenth, it can be charged at high rate. In fact, a full charge can be put into the battery in one hour if the electrical machinery is available for doing this.

"Eighteenth, it is never necessary to remove sediment or replace separators, and also because of its long life a boat equipped with an Edison storage battery can be kept in service and does not have to be laid up on account of battery conditions when it may be required for military purposes.

"Nineteenth, in an emergency sea-water can be used for the replenishment of electrolyte. While if this is done frequently the plates will ultimately lose some capacity, no harm results from. doing it a few times under stress of military necessity.

"Twentieth, oxygen is given off at a low rate of discharge..

Just enough to maintain the atmosphere of the boat in condition for the crew in any long period of submergence.

"Twenty-first, carbon dioxide is absorbed by the potash of electrolyte if the air can come in contact with the liquid. In case of protracted submergence, air can be circulated through the electrolyte by passing it through the drain tube and allowing it to emerge from the filler opening. While this is not a function of the battery, the benefit to clear the atmosphere of carbonic acid gas may prove of considerable value in case of enforced protracted submergence.

"Twenty-second, the plates cannot be injured by rubbing together when the boat is in a seaway, and plate necks cannot be broken off.

"Twenty-third, it cannot generate any explosive gases except when charging and ventilation is outbound. It cannot generate an explosive mixture of gases in the boat under practical operating submerged condition, and is, for the reason that it does not generate any gases whatever on discharge, the safest battery to be used in submarines."

The Gould Storage Battery Company, through their chief engineer, A. S. Hubbard, gives the following information relative to the Gould type batteries they have supplied to foreign govern

ments:

"The foreign batteries consist of 120 cells, 25 plates per cell, pasted positives, pasted negatives; the plates are 1514 inches wide, 1/4 inch thick, 30 inches deep. The capacity is about 2,340 amperes for one hour per cell, giving an output for the 120 cells of about 475 kilowatts for one hour. These cells weigh about 950 pounds each, complete. The cells are individually ventilated by an exhaust blower, and the gases diluted so as to avoid the danger of explosion. The diluted gases are discharged into the atmosphere when the boat is on the surface, and the batteries are being charged and are discharged into the living compartment when the boat is submerged and the batteries discharging. It should be understood, of course, that the gases given off both on charge and discharge consist of oxygen and hydrogen, on discharge mainly of the latter, and very little of it at that, and fur

ther hydrogen in small quantities has no physiological effect. The cells are sealed except at the air inlets and exits to keep dirt and salt water out. The design of the cell permits of an inclination of 40 degrees without spilling the solution."

It is only fair to the lead-plate type of battery to state that many of the troubles ascribed to their use could have been eliminated by careful attention to details of installation, and that there are numerous successful installations in United States Government craft that we are not permitted to describe or illustrate. Enough has been given, however, to show how important the

Fig. 82.-Yacht-Lighting Outfit, With Unit Power Plant, Switchboard

storage battery is when the submarine is lurking in the ocean depths where no other power but electricity could be used advantageously.

Miscellaneous Marine Applications.-Storage batteries are used in many ways on shipboard, and form an essential part of the electrical equipment on a great variety of craft. Owing to the ease of installation, electric-lighting outfits are now available that will function properly in everything from the 30-foot cabin cruiser

EDISON STORAGE BATTERIES FOR YACHT-LIGHTING PLANTS APPROXIMATE EQUIPMENT BASED ON 10-HOUR SERVICE

NOTE: Where 60-volt or 80-volt systems are required, 55 cells and 75 cells, respectively, are recommended.

to the luxurious private yacht. While power-driven outfits are available in which a dynamo is driven by auxiliary steam or gasoline engine distinct from the main power plant used in propelling the vessel, lights may be required at any time during the day or night, so there must be some constant source of current supply. For pleasure craft the continuous operation of an engine and dynamo is inconvenient and often disagreeable, and it is almost