Page:Popular Science Monthly Volume 80.djvu/197

Rh accomplish their main purpose without excluding air or light. Smooth glazed white tile on the walls of the well and large panes of thick glass in the hoods are designed to catch and reflect every available ray of light. There is nothing dark or dingy about such a stairway and its advantages over the foul-smelling, unsanitary halls of the average tenement are too apparent to require enumeration.

The top of each stair well is covered with a pergola like that shown in Fig. 4. The pergolas have iron framework holding glass panels over the top and glass windows part way up the sides, with numerous sections which can be opened when desired. Immediately under its roof the pergola is always open for ventilating purposes, but so that neither snow nor rain can find its way into the hall.

Another feature of the open stairs hardly less interesting than those already mentioned is their intensely practical usefulness in case of fire. It is a remarkable testimonial to their value in this respect that the city officials who pass on such matters have decided that no fire-escapes are required on tenements of the open stair type. The most practical fire proof quality of the open stairs is that they are the one means of leaving