Truss
Collier's New Encyclopedia (1921)
in architecture, an ornamented corbel, serving to support an entablature or balcony, or to conceal the ends of the beams which really support the structure; in the latter case it is frequently made of galvanized sheet iron. In carpentry, a frame to which rigidity is given by staying and bracing, so that its figure shall be incapable of alteration by the turning of the bars about their joints. The simplest frames are of wood, and of few parts. More imposing structures are more complicated, the parts being employed in resisting extension or compression. Composite trusses employ both wood and iron; in fact, few of any importance are destitute of bolts and tie rods. In the simplest form of a truss the tie beam is suspended by the king post from the apex of the angle formed by the meeting of the rafters. In the more complex form the tie beam is suspended by the queen posts from two points. In shipbuilding, a short piece of carved work fitted under the taffrail; chiefly used in small ships. Also, the iron hoop, stirrup, and clasp by which the middle of a lower yard is secured to the mast. It consists of a hoop on the mast, tightened by means of screws, whose open heads engage the eyes of a stirrup, which is swiveled to the hoop on the yard. In surgery, an instrument to keep hernia reduced, that is, to retain da the intestines within the abdominal cavity. The essential feature is a spring on a pad, ad, which is or bandage resting kept above the orifice of protusion. The pad is usually kept to its place by a spring which reaches around the body terminating opposite to the ruptured part. The spring is cushioned, and sometimes has pads to give it bearing on special parts.
What Has Changed in the Last Century
Collier's in 1921 gave equal weight to three trusses, and two of them have moved a long way since. The surgical truss "to keep hernia reduced" was then standard care; today it is regarded only as a stopgap for patients unfit for surgery, since routine repair with synthetic mesh — the tension-free method popularised by Lichtenstein in the 1980s — and laparoscopic techniques have made permanent closure ordinary. The carpentry truss, described as king-post and queen-post frames of "wood, and of few parts," is now mass-produced: light timber roof trusses joined by stamped metal connector plates, designed by computer analysis rather than rule of thumb, and steel trusses spanning far beyond what bolted composite frames allowed. The shipbuilding sense, the iron hoop securing a lower yard to the mast, survives only on sail-training vessels and replicas.
Written for this edition, 2026.