In 1883 he was apprenticed to the trade of printer and compositor.
He was an excellent compositor and pressman; his workmanship, clear impressions, black ink and comparative freedom from errata did much to get him the public printing in Pennsylvania and New Jersey, and the printing of the paper money a and other public matters in Delaware.
As a source for the text it is superseded by the printed edition, and if there is more than one, then by the latest printed edition, which has been revised in proof by the author, or, in certain cases, by his representative; and the task of the textual critic is restricted to the detection of "misprints," in other words, of errors which the compositor (the modern analogue to the scribe) has made in "setting up" the manuscript, and which have escaped the notice of the proof-reader and the author or his representative.
These errors arise from the default of the scribe or copyist, and, in the case of printed books, the compositor.'
So in Triumph of Life, 265, "Whom from the flock of conquerors I Fame singled out for her thunderbearing minion," out seems to be due to the compositor.