100. Lithographic printing. This is another mode of producing
copies in almost unlimited number. The original which supplies
the copies is a drawing made on a stone of a slightly porous
nature, the ink employed for tracing it is made of such greasy
materials that when water is poured over the stone it shall not
wet the lines of the drawing. When a roller covered with printing
ink, which is of an oily nature, is passed over the stone
previously wetted, the water prevents this ink from adhering to
the uncovered portions; whilst the ink used in the drawing is of
such a nature that the printing ink adheres to it. In this state,
if a sheet of paper be placed upon the stone, and then passed
under a press, the printing ink will be transferred to the paper,
leaving the ink used in the drawing still adhering to the stone.
101. There is one application of lithographic printing which
does not appear to have received sufficient attention, and
perhaps further experiments are necessary to bring it to
perfection. It is the reprinting of works which have just arrived
from other countries. A few years ago one of the Paris newspapers
was reprinted at Brussels as soon as it arrived by means of
lithography.
Pages:
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127