After the palm-drill comes the string-drill, wherein the drill is operated by means of a cord twisted about it, the ends being pulled back and forth, and the top of the stick being held firm by insertion in a socket, the latter being grasped in one hand or, when there was only one operator, taken in the mouth. The old Eskimo drill is of this description, produced probably because the surroundings compelled swifter and harder revolutions of the stick to obtain the desired results. A further development is the bow-drill, used by the Eskimo and others, where instead of pulling the ends of the string a bent piece of wood, or bow, is attached to them, the movement of which back and forth rotates the stick. This is used with a mouthpiece for a socket. Another form, but one seldom used for fire-getting, is the pump-drill, where the stick connected with the ends of the cord runs across the drill stock, and sometimes has the stock passing through it, the string being so adjusted around the stock that an up-and-down motion of the crossbar imparts a rotary, reciprocating movement to the stock. This is the form used by the Pueblos for stone drilling, etc.[224] The fire-drill entered into the religious ceremonies of most tribes, and, conventionalised in the so-called cross of the Palenque tablet, which is a development, according to Bandelier, of the fire-drill through ornamentation, it puzzled the Europeans, causing them for a time to imagine that Christianity had preceded Columbus to the New World. [Illustration: SET OF FIRE-MAKING TOOLS, BRISTOL BAY ESKIMO, ALASKA Showing stepped hearth. Mouthpiece is set with a socket-bearing of black stone String Hearth Mouthpiece Drill ] [Illustration: ESKIMO BOW-DRILL]