Another fire-escape, to affix to a window, is composed of a strong sail-cloth, sewed up, to form a long bag or sack, which is open at one end, and of such a length that it will reach from the window to the ground when inclined in an angle of 45 degrees. The upper end of the sack is extended by a hoop sewed into it, and has a cluster of small cords, very similar to the suspension of a hammock, which proceed from different parts of the hoop, and all join in two rings, by means of which it can easily be suspended from two hooks, at the sides of the window-frame. The lower end of the sack is sewed up, but it has an opening in tht side, sufficient to let out a man ; and the borders of this opening must be well hemmed with a cord to make it strong. Two cords are also made fast to the end of the sack, by means of which the lower part can be lashed to any post or fixture at the opposite side of the street, to stretch and retain the sack in the inclined position. The use of this contrivance is evident, as it forms a practicable inclined plane, in which any person can safely slide down to the bottom, and he taken out at the side-opening. It has the advantage of all the others, because women, children, or infirm p.:rsons, however distracted by fear, can be put out of the window into the hoop, and wilt arrive safely at the bottom ; whereas the other contrivances with ropes, though equally safe in reality, have so much more appear ance of danger, that there would be some difficulty in such cases. It is scarcely necessary to add, that the sack must be made very narrow, so that a person can only pass easily through it, and they will then be able to regulate their de scent, by extending their arms and legs, although the width of the street should fequire the inclination to be greater than 45 degrees. In case there is not any sufficient fixture to lash the lower end of the sack to, it must be held by two or three people, who, indeed, if they are careful, will do it more effectually than a fixture, by raising the end when a person comes down towards the lower end, so as to check the descent. For this purpose, two or three rope handles are provided on each side, at the lower end, for the bystand ers to hold ; and these are equally useful when the end is lashed fast. It is plain, that goods of small bulk can be sent down by the same means ; but, to prevent any acci dent of stopping up the sack, the hoop at top is made small er than any other part.
A new fire-ladder, and an elevator for supporting and raising the leather pipe of a fire-engine, have been invented and constructed by Alr William Lamb, builder in Leith. The fire-ladder is nearly upon the same principle as that of Mr Davis, which we have already described. It consists of three ladders, one within another, the two innermost be ing elevated upon the outermost by a rope and pulley, and if necessary by the aid of a windlass. The elevator con sists of two square tubes and a square beam, the first square tube containing the second, and the second containing the square beam. All these are supported in a vertical posi tion by four legs, the lower the first or outer square tube resting on the ground. By means of a pulley moved by a windlass, the second square tube can be ele vated upon the first, and the square beam upon the second square tube, to the height required. About four or five feet below the top of the square beam is fixed a platform, upon which the fireman stands while he is raised to the ne cessary height for the purpose of directing the pipe of the engine, the end of which is fixed upon an universal joint on the top of the beam, so that the fireman has no weight to support, but is solely employed in directing the pipe to the proper part of the building. We are glad to learn that the magistrates of Leith have ordered both these ingenious machines to be constructed for the use of the town, and we trust every other town in Scotland will follow their exam ple. The expence of the ladder when about 42 feet long will not exceed Si.; that of the elevator 131. or 141. The elevator may be applied to many other purposes ; and Mr Lamb proposes also to construct it, so that any person may raise himself.
An account of a fire ladder which supports itself, will be found in the Acta Petropolitana,vol. i. p. 1. See also Leo pold's Theatrum Machinarum, tab. 54. 57 ; Emerson's Me chanics, 228 ; Varcourt, Mem. Acad Par. 1761, Hist. 158 ; Collins, American Transactions, tom. iv. or Repertory of Arts, vol. xv. p. 25 ; Audibert, Mem. de Institut. tom. iv. or Repertory, vol. i. p. 439. (J. r.)