Page:Rudimentary Treatise on the Construction of Locks (1853).djvu/220

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ON LOCKS.

even to get a second man to assist the first in any way, is impossible, simply for want of room.

The whole of the doors and all the surfaces of such passage should be painted a dull, lusterless black. No one who has not tried it, has any idea of the difficulty of illuminating such a black passage, by even several candles, sufficiently to perform any delicate mechanical operation; and good light is essential to the safe-breaker.

In banks there is no better plan than has been ere now adopted of making the iron safe a great cube, with the door at one side, placing the whole safe with its bottom resting upon the stem or plunger of an hydraulic press, the cylinder of which is fixed in the bottom of the pit in the solid earth, of a size capable of enabling the whole safe to be bodily lowered down into the cavity at the end of the day's work, and pumped up again out of its hiding-place the next morning. The lever of the hydraulic pump is taken away, and the socket into which it fits is plugged, and the plug locked into its place, and then the pump—situated in a recess in solid masonry—is itself locked up. The top of the safe itself, when it has been lowered to the bottom of its chamber, stands 10 or 12 inches below the floor-level of the stone floor, and a pair of iron doors is then closed over it and locked down.

A safe executed in this way, though requiring a considerable expenditure at first, if well done, might bid defiance to anything almost, even unlimited gunpowder, for some days. The only addition of safety that almost could be conceived would be that adopted at the bullion vaults of the Bank of France in Paris, where these, situated in casemates two stories under ground, are only approachable by one narrow, winding staircase, which can be itself, in case of emergency, rapidly rendered useless, and the cylindrical well in which it is placed filled up with about 30 feet in depth of water, which cannot be pumped out until a continuous supply be shut off by distant means only known to one or two trusted employés.