Page:Popular Science Monthly Volume 92.djvu/820

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��Popular Science Monthly

��5eam Bolt

��ing and preventing them from collapsing or lifting. If weakness is suspected or reported by the divers, a mixture of paraffin and small blocks of cork is used in preference to either of the materials alone, as it forms a stronger and more binding mass, extending as a beam from one side of the ship to the other. After the upper decks have been sealed in this manner, air can be pumped into the vessel to force more water out, either through a pipe provided for this purpose or through breaks in the bottom. In the case of torpedoed ships with large openings in the sides, considerable pre- liminary repair work by divers may be necessary to close the upper portions of the rents or to con- struct bulkheads extending far enough down.

The operation is readily understood by reference to the description under the accompanying illustra- tion. When the seacock is opened, water rises in the hopper to the level of the sea. When now the centrifugal pump is started it pumps water into the sunken vessel. If there are no holes in it, an out- let for the surplus water is supplied by means of a pipe raised in the ship's bottom. The buoyant material — small blocks of cork or balsa wood boiled in paraffin — is now dumped into the hopper till its weight forces it to mix with the inflowing water, and it is thereby taken into the pump and forced down through the piping. Released at the lower end of the inner pipe it rises, but the water with which it is mixed, seeking the outlet pro- vided for it in the other hatch, produces currents carrying the cork along, so that eventually it reaches all parts of the ship, rising the while against the decks. When a sufficient amount of this buoyant ma- terial has taken the {)lace of water, the ship rises.

If the ship is too weak from prolonged corrosive action of the water, and the decks liable to lift, heated paraffin is run

��into the hopper with the cork. To pre- vent it from cooling and hardening too soon, air is pumped into the space between the inner and the outer tubing. Some air is allowed to be forced into the hold together with the cork and paraffin and helps to carry these substances toward leaks and sealing them.

���How Decks and Hatches Are Secured

The upper deck of a sunken ship may be strengthened by hardened deposits of cork and parciffin under it. To secure the hatches, heavy beams are weighted and lowered into the hold and placed in position by divers. Next the weights are removed and the buoyancy of the beams holds them in posi- tion. Bolts are lowered and connected with the beams. Then a second set of beams is placed on top of the hatch and connected with the tie-bolts. This arrangement effectually distributes the strain on any one deck to all the decks of the ship

��Lighting Up East India — How America Helps

INDIA is making slow but steady progress in introducing more mod- ern lighting methods. All public lighting in the large cities of India is by elec- tricity ; but in smaller cities the methods of lighting, public as well as private, are still very primitive. The use of illuminating gas is extremely restricted and lamps in which pe- troleum or vegetable oils are burned are used to some extent, though not generally.

For native festivals — and there are a great many of these — large kerosene lamps of an elaborate pat- tern are much used. They are known in many locali- ties as "Washington Lights" and were original- ly brought to India from the United States. At various religious proces- sions and especially at wedding proces- sions as many as twenty or thirty of these lamps are carried on the heads of bearers who are engaged for the occasion and paid a fixed fee.

These lamps are high-pressure kerosene lamps constructed upon the principle of the kerosene torches used in the United States. The light is protected by a mica chimney and is very brilliant. Colored globes are sometimes used. These lamps are no longer imported from the United States but are manufactured in Bombay. The "Bombay Lights" cost about five dollars or six dollars, while the imported kind can not be bought for less than sixty-five dollars apiece.

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