an outside staircase, all the doors leading to it being treated as external doors. The lift is similarly treated.
Double iron doors, lined or cased with heat-repelling material, separate the various compartments on each floor from the staircase and from each other. These doors are so arranged that they can be closed from the external balconies, and thus any compartment in which a fire occurs can be isolated without the necessity of entering it, or indeed of entering the building.
The windows are closed by external sliding shutters, running upon rails projecting from the outside face of the walls. These shutters are so constructed that they can be opened by the firemen from the outside; and easy access is given to them by the balconies, which are carried round the building at the level of every floor. Iron balconies are shown on the plan and section, since in most cases the heat issuing from the windows will not be sufficient to affect its strength; but where very inflammable goods are to be stored it will be best to corbel out in the brickwork, and to arch from corbel to corbel to form the balconies. Permanent means of access to the exterior of every opening in the walls is a most important provision, allowing any part of the building to be inspected independently, and fire discovered or extinguished, without opening the doors of the adjoining compartments.
The roof is nearly flat, having but fall enough to carry off the water. It may be made water-tight by a layer of asphalte, and then paved with tiles; but a flat roof is not an essential feature of fireproof construction, since, if the ceiling be vaulted in brick, as shown, a roof of any pitch may be constructed above it, framed entirely of iron, and covered with slates tied by copper wire to iron laths, or with metal tiles. It is obvious that nothing combustible must be stored in the space between the roof and the ceiling.
A tank is shown at one angle of the roof, to contain a supply of water in case of fire, and it can be kept full by the ordinary means of supply of the neighbourhood. If a portion of the top storey can be given up for the purpose, the rain-water of the roof can be stored without incurring a water-rate. From the tank, pipes are conducted outside the building and furnished with unions near the windows of each compartment; so that a hose-pipe can be instantly attached by anyone standing in the balcony, and the whole contents of the tank discharged into any of the compartments, without the building being entered.
In the case of a fire occurring in any compartment, two methods of proceeding are available. The compartment can be isolated and completely shut up until the fire either burns itself out or is extinguished for want of air; or the shutters can be opened, and a larger quantity of water can be discharged upon the burning goods, immediately the fire is discovered.