nSiderographyThe art or practice of steel engraving; especially, the process, invented by Perkins, of multiplying facsimiles of an engraved steel plate by first rolling over it, when hardened, a soft steel cylinder, and then rolling the cylinder, when hardened, over a soft steel plate, which thus becomes a facsimile of the original. The process has been superseded by electrotypy.
Century Dictionary and Cyclopedia
nsiderographyThe art or practice of engraving on steel: particularly applied to the transfer process of Perkins. In this process the design is first engraved on a steel block, which is afterward hardened, and the engraving transferred to a steel roller under heavy pressure, the roller being afterward hardened and used as a die to impress the engraving upon the printing-plate.