Perhaps sheets of India
rubber of uniform texture and thickness, may be found to answer
better than this composition; or possibly the ink might be
transferred from the copper plate to the surface of a bottle of
this gum, which bottle might, after being expanded by forcing air
into it, give up the enlarged impression to paper. As it would
require considerable time to produce impressions in this manner,
and there might arise some difficulty in making them all of
precisely the same size, the process might be rendered more
certain and expeditious by performing that part of the operation
which depends on the enlargement or diminution of the design only
once; and, instead of printing from the soft substance.
transferring the design from it to stone: thus a considerable
portion of the work would be reduced to an art already well
known, that of lithography. This idea receives some confirmation
from the fact, that in another set of specimens, consisting of a
map of St Petersburgh, of several sizes, a very short line,
evidently an accidental defect, occurs in all the impressions of
one particular size, but not in any of a different size.
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