Tortoise shell, or rather scales, is a horny substance that covers the hard strong covering of a bony cotexture, which covers the Testudimbricata, Linn. The lamellae or plates of this tortoise are 13 in number, and may be readily separated from the bony pirts by placing fire beneath, the shell, thereby they start asunder. They vary in thickness from one-eighth to a quarter of an inch, according to the age and size of the animal, and weigh from 5 to 25 pounds. The larger the animal the better is the shell. This substance may be softened by the heat of boiling water; and if compressed in this state by screws in iron or brass moulds, it may be bent into any shape. The moulds being then plunged in cold water, the shell becomes fixed in the form imparted by the mould. It the turnings or filings of tortoise-shell be subjected skillfully to gradually increased compression between moulds immersed in boiling water, compact objects of any desired ornamental figure or device may be produced. The soldering of two pieces of scale is easily effected by placing their edges together, after they are nicely filed to one bevel, and then squeezing them between the long flat jaws of hot iron pinchers, made somewhat like a hair dresser's curling tongues. The pinchers should be strong, thick, and just hot enough to brown paper slightly without burning it. They may be soldered also by the heat of boiling water, applied along with skillful presssure. But in whatever way this process is attempted, the surfaces to be united should be made very smooth, level, and clean ; the least foulness, even the touch of the finger, or breathing upon them, would prevent their coalescence.
This article was originally published with the title "Tortoise Shell" in Scientific American 8, 46, 368 (July 1853)