PYROGRAPHY, from Tr vp, fire and to write, literally to write by fire. A method of making impressions on wood, leather, etc., by means of heated metal tools or burnt sticks. The art was early practised by the Egyptians who used crude iron bars that had been pre viously heated in fire. A modern form of pyrographic apparatus consists of a tube about six inches in length and about half an inch in diameter provided at its lower extremity with a screw-cap and a small support. At the other end there is a rod to which the drawing point is affixed. For the formation of the com bustible gas and heating of the rod sulphuric ether is usually employed. The gas when gen erated is forced to the metallic point by means of air pressure, and after the flame has been regulated a person may work for two consecu tive hours at an expense of about one-half cent per hour. The vapors disengage themselves constantly and feed the small flame which is barely perceptible. The heat is always uniform,
and even on leather a sure and sharp execution of the design is possible. Electrically heated points are also used. The effects produced by the pyrograph are, equal in many respeetato the fine crayon drawings, and when colored and varnished present a very pleasing effect. The finest and most delicate 1:nes can be drawn and there is no danger of burning holes in the ma terial. The right hand being engaged in the execution of the piece to be ornamented leaves the left free to turn the object in any desired position while the work is in progress.
Pyrography is taught in many trade schools, and is used mainly for ornamenting leather and wood. Consult Bolas and Leland, (Pyrography and Wood Roasting' (1899) ; Maude, (Pyrog (1891).