Issue 19.

  =Perforation=                14.

                                                           Unused.  Used.
                                               by what we call the injudicious use
of the perforation-gauge, as many examples of the aberrations of the
machines as they please, or as their time and purses will permit. We
think they will find it in some cases, say in that of the Five Shillings,
to be a laborious, an expensive, and above all an unsatisfactory, task.

In order to ascertain the mean gauge of the B machine, the only possible
way would be to get a line of perforations representing the whole length
of the machine, and measure it. The longest line of perforations we
have been able to experiment on is one of 124 mm.; this contains 72
holes, giving a mean gauge of about 11⅔ in the 2 centimetres. In some
places in this line nearly 13 holes can be counted in the space