Iron by itself is a very strong metal and was used especially during the nineteenth century for construction and railroad manufacturing. Yet, several methods have been invented to add to its strength, including alloying, compositing, and reinforcing. Corrugating is an efficient method of reinforcing sheet iron--marks, irregularities, or (usually) parallel, curved marks or ridges and hollows are shaped on the surface of a sheet of iron, to which the cement sticks better than on a flat surface. The corrugate waves, or ribs, add significantly to the strength and rigidity of sheet iron while not adding much to its weight. The ribbing has virtually the same effect as reinforcement framing.

Corrugated metal was first used in the Mediterranean area as early as 500 B.C. Bronze was corrugated by hammering it into the form of buckets. One of the first attempts to mass produce corrugated metal was that...