In the erection of fire-proof buildings, we are forced to do the best we can with iron while using it in the most varied capacities; but when its use can be spared, let me entreat you to rid yourselves of it; where it must be employed, use it rationally and constructively; but better not decorate it at all, than imitate styles not in harmony with its constructive properties. As all iron must be painted, I am inclined to believe that the best method of decorating it is in colors; for this treatment the iron must be plain and simple, and the colors may be proportionately brilliant. With regard to other materials, I would suggest nothing more than is said above—in all things build rationally. First, let your work be strong and well balanced—no part too heavy—no part too light. Then decorate it in harmony with its constructive features, never concealing materials, except where necessary to protect them, and emphasizing the main lines of the construction by ornamentation. Thus only can the great problem of the day be solved, and the fire-proof architecture of the nineteenth century be made worthy of a rational and progressive age. NOTE.—An inspection of HARPER & BROTHERS’ building, since writing this paper, has convinced me that the principle of division into horizontal compartments has been carried out more thoroughly in it than in any other building of the kind. There are no openings through the floors. It contains neither interior stairs nor hoistway; both are on the exterior. The stairs are in an isolated tower approached by bridges, and the hoistway is without enclosure. This arrangement is however extremely inconvenient. FOOTNOTES: [A] But by combustible material, I do not by any means intend what the insurance companies call hazardous, but dry goods, books, and similar things, which will burn independently of the building in which they are contained. [B] (That disaster was owing also to the fact that the beams, other than girders, were made only of No. 12 sheet iron with flanges of 2 inch angle iron). THE NEW MERCANTILE LIBRARY, PHILADELPHIA. The history of the origin of public libraries is simple. Very few persons who possessed a desire to own books of great value could, in early times, afford to gratify their wish, owing either to want of the necessary means, or the very great scarcity of many works of intrinsic value. Before the invention of the great art of printing it is well known that all communicated learning was, of necessity, confined to manuscript on vellum. And that the only mode of repeating books was by transcription. The number of copies being extremely limited, it became necessary to have public places at each of which a copy might be placed for the use of those who desired to read, and as that number was in those days limited also, it was customary for some man of learning to read aloud to an audience.