REPORT OF MR. NELSON L. DERBY.
379
I now pass to a matter of especial interest to Bostonians, and, in fact, to Americans in general, and one which can nowhere be better studied than in Vienna. I refer to the methods of building which have for their object the insurance of stability and avoidance of the danger of fire, with the various Austrian laws affecting the same. These subjects must necessarily be treated together, as they are intimately dependent upon one another ; and in connection with them it will also be necessary to refer to various sanitary regulations which might also with advantage be introduced at home. Among the precautions to be taken in rendering a building fire-proof, the most important are those tending to confine the fire to the point at which it first appears. This is here accomplished by constructing the interior as well as exterior walls of masonry, making the floors and ceilings as far as possible fire-proof; completely isolating the woodwork of the roof from the remainder of the building, and avoiding the use of wood or other combustible matter generally in staircases and the skylights opening upon them. To prevent the roofs of adjacent houses from communicating fire with one another, they are separated by walls of masonry rising a foot above their upper surface and are in all cases covered with slate, tiles, metal or other uninflammable substance. To prevent the burning roof from falling through into the lower stories, the floor of the attic is made both incombustible and of great strength. The fire-proof floors here employed are of several varieties and materials. A wooden floor is rendered incombustible by a filling of dry mortar, gravel or sand, supported by a rough boarding placed either upon or between the rafters. The depth of this layer is generally six to eight inches, and upon its upper surface comes the flooring, nailed to joists, which are buried in the filling. I have never heard of a case "where a fire in Vienna has penetrated through this filling to the beams or rafters below. If fire breaks out in the room below, the plaster of the ceiling is sufficient to protect the beams, since there are no partition-walls of wood to strengthen the flames, and the burning of doors and windows, With their casing, together with the furniture, is insufficient to destroy it. In case of rooms used for the storage of large quantities of combustible matter, there are especial laws