\Sid`er*og"ra*phy\, n. [Gr. ??? iron + -graphy.]
The 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 The process has been superseded by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.