In iron-work the manifestation of a true constructive principle is beyond all things desirable. Iron, being a strong material, should not be formed into heavy masses unless immense weight has to be sustained, or very great strength is required. If we form lamps, candelabra, and such works of iron, it is obvious that the portions of metal employed in their construction may be thin, as the material is of great strength. Were we to form such works of wood, then a greatly increased thickness of material would be necessary, in order that the same strength be secured, as wood is not nearly so strong as iron.
My remarks will have special reference to wrought-iron, as cast-iron cannot so fully be said to have a constructive character. The small railing (Fig. 163) is an admirable illustration of a true constructive formation, as the parts are all held together, and strengthened to a wonderful degree, by the introduction of a horseshoe-shaped member. This railing is worthy of the most careful study, for its strength is great. Besides strength we have also beauty. The horseshoe form, especially when judiciously applied, is far from being offensive. Utility must come first, and then beauty, and so it does in this particular railing; but here we have great simplicity, and a correct structural character has been arrived at in its production rather than any elaboration of the principles of beauty.
From the catalogue of J. W. Dovey, of Manchester, I select an illustration of structure in the form of a candelabrum which is highly satisfactory in character as a simple work (Fig. 168). There is a solidly-formed heavy base, an upright stem terminating in a candle-holder. There is an arrangement for catching waste grease, and extra strength is given to the stem by four slender buttress-like brackets, which are securely and well attached to the base and to the stem above; and these are strengthened by two hoops, which prevent their bending under pressure.
Figs. 169 and 170, the former being a ridge or wall cresting, and the latter a stair railing, are each illustrations of a correct treatment, inasmuch as strength (a structural quality) and beauty (an art quality) are secured at the same time. Fig. 169 is admirably constructed, only it is a little slender above the middle horizontal line. These two illustrations are also from Mr. Dovey's catalogue.