The relative dimensions of the several impressions were 5.5,
6.3, 8.4, 15.0, so that the largest was nearly three times the
linear size of the smallest; and Mr Lowry assured me, that he was
unable to detect any lines in one which had not corresponding
lines in the others. There appeared to be a difference in the
quantity of ink, but none in the traces of the engraving; and,
from the general appearance, it was conjectured that the largest
but one was the original impression from the copperplate.
The means by which this singular operation was executed have
not been published; but two conjectures were formed at the time
which merit notice. It was supposed that the artist was in
possession of some method of transferring the ink from the lines
of a copperplate to the surface of some fluid, and of
retransferring the impression from the fluid to paper. If this
could be accomplished, the print would, in the first instance, be
of exactly the same size as the copper from which it was derived;
but if the fluid were contained in a vessel having the form of an
inverted cone, with a small aperture at the bottom, the liquid
might be lowered or raised in the vessel by gradual abstraction
or addition through the apex of the cone; in this case, the
surface to which the printing-ink adhered would diminish or
enlarge, and in this altered state the impression might be
retransferred to paper.
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