The Collaborative International Dictionary
Copygraph \Cop"y*graph\, n. A contrivance for producing manifold copies of a writing or drawing; -- made obsolete by later developments in copying technology; see xerography.
Note: The writing or drawing is made with aniline ink on paper, and a reverse copy transfered by pressure to a slab of gelatin softened with glycerin. A large number of transcripts can be taken while the ink is fresh.
Various names have been given to the process [the
gelatin copying process], some of them acceptable
and others absurd; hectograph, polygraph,
copygraph, lithogram, etc.
--Knight.
Wiktionary
n. (context dated English) An early means of producing multiple copy of a document by means of pressing it against a slab of gelatin softened with glycerin and making further copies from the resulting reversed image.
Usage examples of "copygraph".
The bed was strewn with books and copygraphed sheets of instructions from his remote correspondence tutors.