This system of mailing letters by means of a specially constructed chute connected with the receiving box at the bottom, has come into such general use in public buildings, office buildings, apartment houses and hotels, that the restrictions affecting the same and what is required in the way of preparation, should be known to architects.
The system is installed by the patentees, under regulations of the Post Office Department governing its construction and location, and for this reason it is well to consult the makers, the Cutler Manufacturing Company, Rochester, N. Y., before permanently locating the apparatus on the plans.
It may be placed in any building of more than one story used by the public, where there is free delivery and collection service, in the discretion of the local postmaster, subject to whose approval the contracts are made.
The chute is required to be in removable sections and a continuous, rigid, vertical support is absolutely necessary. It must be of metal, the front of plate glass, and bear the insignia prescribed by the department; and the whole apparatus when erected and the Government lock put on the box, passes under the exclusive care and control of the Post Office Department, and the chutes become a part of the receiving boxes. These boxes may be of various patterns and highly ornamented; they are furnished by the makers
Fig. 523 in connection with the chutes. The work of preparing a support for the chute and cutting and finishing the openings in the floors may be included in the general building contracts, and details showing the usual arrangements are therefore given.
The requirements for what the manufacturers call "preparatory work" are a flat, vertical, continuous surface not less than 10½ inches wide, extending from the floor in the ground story to a point 4 feet 6 inches above the finished floor in the top story, and an opening in each floor directly in front of and centred upon this surface. These openings are neatly and easily finished, and their size and shape determined by setting in them thimbles of iron which are furnished and delivered by the patentees, as part of their contract.
In ordinary cases a casing of wood, suitably moulded and finished to match the trim of the building, answers every purpose. Such a casing is shown in plan, Fig. 521, with the opening finished by the iron thimble.
In buildings (or sometimes in but a few stories) where a more elaborate finish is de-' sired, marble is substituted for wood, the form and construction of the casing being adapted to the material, but of course without disturbing the size and form of the front surface.
Iron angles are used where the use of wood is objected to, or where it is necessary to run the chute in front of an elevator screen or in other locations where a solid wall is not available to support the casing. Two x 2x¼-inch square root angles are generally used, turned so as to form a flat channel, as in Fig. 522, but sometimes - where it is desirable to fill up the space between them and the elevator screen - reversed, as in Fig. 523. The angles are usually bolted to the beams, and in any case must be straightened so that they are without twists or kinks, and the surface which receives the mail chute is perfectly plumb and flush in all stories.
This work of preparing the building is now often included in the mail chute contract, as it has been found for many reasons undesirable to separate it. Care should be taken, therefore, in specifying, to state whether the work of preparation is to be included with the figure for the mail chute or whether it has been otherwise provided for.
Fig 524 - Preparatory Work Complete.
Fig. 524 gives a general view of the mail chute casing and floor openings ready to receive the mail chute.
Essential points to be remembered are: First, that no bends or offsets can be made - a vertical fall is absolutely essential; and second, the entire apparatus must be exposed to view and accessible - that is, it is not permitted to extend behind an elevator screen or partition or through any part of the building except a public corridor.