ore suitable printing machine.

He found there were other means to be employed beside a Type Press,
and having examined the Theory of his Invention put it in Practice,
by erecting a Rolling Press of another Construction than what is
used for printing Copper Plates.

[Illustration:
ILLUSTRATION in _Biblia Sacra_ published by Hertz, Venice, 1740,
vol. 1. Originally cut by Jackson for Albrizzi's _Istoria del
Testamento Vecchio e Nuovo_, Venice, 1737.
Actual size.]

In Paris Jackson had suggested using a cylinder press for printing wood
blocks. The gentlemen to whom the suggestion was made, Count de Caylus,
Coypel, and Mariette, were sure that the enormous pressure would split
the blocks. The Englishman, on the contrary, felt that the pressure,
properly controlled by a chase, would hold the blocks together. Printing
would be much more rapid and the exceptional vigor of the impression
would suggest a hand drawing. The use of cylinder presses for
chiaroscuro printing was already well known to experts. George Lallemand
and Ludolph Businck, sometime between 1623 and 1640, had used not one
but a series of six cylinders on three joined presses, with three
printers simultaneously inking separate blocks with different tones.
Impressions were then printed from each block in succession.
Papillon[26] described this press, and also another with a special chase
designed at an unspecified date by Nicolas Le Sueur. Jackson's prints
show a much stronger impression than those of Businck or Le Sueur. No
details of his press are known, although Thomas Bewick[27] reported that
Jackson as an old man had shown him a drawing of its construction.

[Footnote 26: Papillon, vol. 2, 1766, pp. 372-373.]

[Footnote 27: Bewick, 1925, p. 213.]

[Illustration:
Illustration for Albrizzi's _Istoria_, in which it was cut No. 136.
From Hertz's _Biblia Sacra_, vol. 1.
Actual size.]

The cylinder press of Jackson's design was finished in 1735 and paid for
by the income from prolonged sieges of work for printing offices. But
the overwork and resulting exhaustion laid him low; a serious illness
followed and for several months he was close to death. When he
eventually regained his health he found that his cuts for Baglioni and
Pezzana had been copied and mutilated by an engraver at Ancona. This
pirate was encouraged by the head of a large printing establishment
newly founded in Venice, who thereupon offe