The most extensive attempt to build a fire-proof building for manufacturing purposes was the enterprise of Harper & Brothers. This was one of the pioneer buildings of the new dispensation. The Harper girder is well known; it is an ornamented cast-iron beam, with a tie rod, and was the father of the truss beam, now so extensively used for supporting the rear walls of stores. It has been succeeded by the built-up beam, now generally used for girders, and the double rolled beam. It was eminently a constructive beam, using iron according to its best properties, cast-iron for compression and wrought-iron for tension. I doubt not that it will some day be again used where girders are required. The built-up beam was invented for the restorer of the “pure” styles, who think that furring strips, laths, plaster and a modicum of run moulding, not to forget “a neat panel on the soffit,” to be a good substitute for the honest lintel of the Greeks, and more artistic than the constructive beam which James L. Jackson & Bro. designed and executed for the Harpers. When men are no longer ashamed to display good iron construction, and bend their artistic conceptions to their constructive skill, we may hope to see something like the Harper beam revived, and decorated in a manner befitting its use. But I fear that this will be done when a more rational generation than our own holds the sway. But to return. In Harper’s building, as in the Cooper building, the deck beam was used for the floors, and brick arches, such as those now in use, were employed. The deck beam has also gone out of use. When first employed, iron beams were not made for houses, but for ships. The I beam, has replaced the deck beam for the former purpose. And in this connection, I would suggest an inquiry into the practicability of using the deck beam inverted. It has always seemed to me that the broad flange would best sustain compression, and that the roll, having the form of a round bar, would best resist tension. The matter of the bearings is easily remedied by a cast-iron shoe on each end of the beam and bolted to it. This shoe, with a broad foot, would answer the purpose both of template and anchor, and if made to project from the wall and assume an ornamental shape, might become a visible and constructive bracket. The deck beam inverted would evidently present the best appearance from below in cases where the flooring is placed on top of the beams—the various methods of doing which I propose to discuss further on. Should the deck beam come again into use, it might be made of more ornamental form without detriment to its strength. The bottom roll or flange could be moulded in various ways. But, except in so far as the floors are concerned, the Messrs. Harper’s building is far from being fire-proof. There is much wood-work in its inside finish, and the contents being of a highly inflammable nature, I fear that fire would have its own way in that building unless early checked.