In erecting modern fire-proof buildings, especially in so far as iron work is concerned, all the conditions imposed upon the architect are different from those which existed in past ages. The same may be said of the use of iron in any building. Subserviency to style, when the material used is not such as was the controlling element of that style, is destructive to all good art; for there can be no truly artistic effect except that which is produced by the best use of material, and its decoration in best accordance with its nature. If the use of iron is ever to lead to the erection of buildings worthy of being called works of art, such a result must be attained only by the recognition of this principle. The best thinkers have doubted whether there can be any such thing as architecture in iron, assuming, of course, that to be called architecture, the material must be constructively used; and there is good reason for these doubts. An iron building does not always require the force of gravity to maintain the cohesion of its parts; it possesses such properties that it may be swung in the air or balanced on a single point, if it is necessary so to do. It is a machine admitting of as little decoration as a steam engine or a printing press. If iron alone were used for buildings, constructive necessity and economy combined, might lead us to build houses like steam boilers or water tanks. What has been done thus far toward the erection of iron buildings on constructive principles? We can only recur to the buildings of the Crystal Palace pattern. We had a beautiful one in New York, admirably constructed, and well designed for its purpose; but even that building was decorated in the Moresque style, perhaps as nearly appropriate to the material employed as any that could have been selected. Here originality in treatment failed, just where it was wanted. The same constructive principles were involved in the design of this building which would have been involved in the erection of a fire-proof building. In this respect it was a success.