Engraving On Stone may be said to be connected with Lithography only by the chemical nature of the processes of printing; for in every other respect it is an entirely distinct mode of reproduction. We describe it in this place, however, in accordance with our plan of first describing all those manual methods of Lithography in which one colour only is used.

138. Engraving on Stone is performed by cutting through a film of gum on or in the surface of the stone, and filling up the incised parts with a fatty ink. The printing is performed by a combination of the dabbing method of copperplate and the damping method of lithographic printing. Its advantages are—facility of production; accuracy of drawing; minuteness of detail; and clearness, of impression. It is especially applicable to the reproduction of drawings by architects and civil and mechanical engineers when drawn to a small scale; and being performed by tools analagous to those employed by the architect and engineer themselves, errors due to freehand engraving or drawing can be entirely avoided.

139. The Tools.—These will not involve the lithographer in much extra expense, as he may make some of them himself. A diamond point is undoubtedly a very useful instrument, but it is expensive, and will cost as much, perhaps, as all the rest of the tools put together. Added to this, the beginner will find that it requires more practice to use it properly, and will not equal the precision of the steel points about to be described.