When conflagrations occur in old, dilapidated, and, for the most part, frame buildings, it is generally not so much an object to save them as to prevent injury to the surrounding property ; and in case the supply of water should fall short, we have, at present, no adequate method of staying the progress of the flames. The invention we are about to describe is intended for this purpose. Fig. 1 is a perspective view of the whole, while Fig. 2 is a longitudinal section of the vertical sliding rods detached. A truck is first constructed, consisting of un iron frame, A, from thirty-five to forty feet long, and of convenient width, and this is mounted on four wheels, B, on the axles, c, attached to the truck by ring bolts to enable it to turn a sharp curve in a small space. On each end of A arc erected four iron uprights or iron tubes, D, which are connected at the top by frames, E, on which are journals for the axles of the chain wheels, F. Other chain wheels, G, are mounted on the lower part of the frame, A, and thcse curry the endless chain, H. On the axles of the lower chain wheels, G, are mounted two ratchet wheels, X, one on each, with pawls y, hinged to the frame, and locking into their teeth. t In the center of the truck, nearly filling the "A spnce between the chain wheels, is arranged C longitudinally with the frame, A, a reller sup-Sported at each end on journals in bearings, I, erected on the frame. This roller is constmcted with two flanges, J, keyed on a shaft, with a series of wrought iron rods or tubes connecting them, around and near their peripheries. The flanges, J, may either, one or both, form tiller or sprocket wheels, so as to be turned by hand to rotate the roller. This roller forms a foundation On which to wind the necessary quantity of sheet iron, in sheets of about thirty feet wide, (just the length of the roller,) and. abont twelve feet dcep, and are so made at the top and bottom as to form one continuous sheet. On the inner end of the frame, E, are erected standards, K, with capping pieces, L, to support their upper ends. To these up- rights are jointed clamps, M', at their top and bottom, through which rods, N, are free to play vertically. A bar or tube, 0, having an eye at each end, spans and connects the two rods, N, horizontally above the sheet roller. These lods, N, nrc also provided with a socket, P, which may be secured to them at any point by a set screw. To these collars are jointed hoob, Q, of a suitable form to hook into the links of the endless chain, H. To the npper edge of the sheet, W, are attached a number of hooks, p, by which it is connected with the bar, O. When it is intended to raise the sheet, pins, S, are passed through the rods, N. The hooks, Q, are conneeted with the endless chains, II, and their collars secured by set screws to the rods, N, near their lower ends. The chain wheels, G, are then rotated by cranks, V, on their axles, which raise the rods, N, and with them the bar, 0, aud sheet, W, by unwinding it from the roller until the ends of the bars come in contact with the lower clamps, M, which me then opened, to allow it to pass up, and closed again, and the upper ones are opened, the rods, bar and sheet pass through, and they are again dosed. The screen is then supported by the ends of the bar, 0, resting on the clamps, 11', in the position represented at Z, whilst the rods, N, are released from the chains and allowed to slide down to their original position. A man then ascends by the rattlings, or in any other way, to the head of the endless chains, and secures the cross bar, 0, to the rods, N, by inserting a pin, or tighteIling a colbor by a set screw underneath them, and at the same time attaches guy chains, R, to the cops, T, on the tops of N. The hooks, Q, being again connected with the endless chains and rods as low down as possible, they may be raised as befora, until a section of rod (made of wrought iron tube, with socket joints, by riveting a shank, a, seen in Fig. 2,) can be connected at their lower ends, which are then let to rest on the feet, U, whilst the collar and hook can be again lowered, and connected as before, near the bottom, with the chains and rods, when the sheet is raised by turning the chain wheels. This may be repeated by adding sections of rod, until the screen is raised to the necessary hight to proteet the neighboring property, when the guy chains, R, are to be anchored to steady the top. A number of these screens may be arranged in a line, or mound a burning building, so as to protect, in a great measure, the surrounding property. Further information and particulars maybe obtained from the inventor, Thomas Odion, of Portsmouth, N. H. It was patented September 29, 1857.