It is impossible by
any drawings to solve difficulties such as these, experiment
alone can determine their effect. Such experiments having been
made, it is found that if the sides of the steel punch are nearly
at right angles to the face of the letter, the bur produced is
very inconsiderable; that at the depth which is sufficient for
copperplate printing, no distortion of the adjacent letters takes
place, although those letters are placed very close to each
other; that the small bur which arises may easily be scraped off;
and that the copperplate is not distorted by the condensation of
the metal in punching, but is perfectly fit to print from, after
it has undergone that process.
321. The next stage in the progress of an invention, after
the drawings are finished and the preliminary experiments have
been made, if any such should be requisite, is the execution of
the machine itself. It can never be too strongly impressed upon
the minds of those who are devising new machines, that to make
the most perfect drawings of every part tends essentially both to
the success of the trial, and to economy in arriving at the
result.
Pages:
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354