8. Fire-Escape
OF A FIRE-ESCAPE, On a retarding Principle.
This is a recollection from the specification of a Patent which I took out above thirty years ago, and in which I huddled together as many objects as a child would like to see in a box of play things. I perhaps acted, then, according to the words of a French proverb--"abondance de bien ne nuit pas;" but in so doing, I fell into the charybdis of another French proverb--"qui trop embrasse, mal étreint," (a wide embrace cannot be a strong one) and in so doing, paved the way to much litigation--which happily did not occur.
The intention of this Machine, as represented in Plate 46, fig. 2, was to retard the fall of any body, or person, suspended to it, so as to prevent any concussion on reaching the ground. The means are brought to view in the perspective sketch given of the Machine. It is a kind of jack, inclosed in a case, and supposed to be laid carefully aside in the house represented in fig. 1 of this Plate. The Machine has a barrel, much like that of the jacks used for roasting; round which a rope is coiled, of sufficient length to reach the ground: and a wheel, connected with this barrel, works in an endless screw, which turns a shaft also like that of a common jack, but somewhat stronger; and finally, to this shaft is fixed a small cross piece, carrying, on pins, two weights y z, inclosed in the fixed barrel x; by the centrifugal force of which enough friction is created, to prevent the acceleration of the falling body--whether a person or weight of any kind.
There is, moreover, a jib a, fig. 1, fixed between some, or all, the windows of the house whose inhabitants it is wished to guard from the danger of fire; this jib having the property, from the form of it's foot, of taking by the suspension of any weight to it, a position perpendicular to the wall: Insomuch, that by the act of suspending the Machine to the jib--engaging the wrist in the noose n, and perhaps the foot in another loop of the same cord; a person may safely flee those dangers from fire, of which so many persons become the unhappy victims.
Since the 46th. Plate was engraved, it has occurred to me, that a method should have been shewn for raising the cord n, (fig. 2) after each descent. This operation might be performed by a handle put on the axis of the Machine, accompanied by a ratchet on the wheel, just like the similar parts of a jack for roasting. But, lest the inmates of a house on fire, should not have presence of mind enough to perform this operation, it might be better to have a spiral spring in the Machine, to be wound up by the descending body, and of force sufficient to raise again the cord after such descent.