bad mark against them
in the future, and they feel its effects next time promotions or
"rises" are being handed out.

Altogether, though the work is interesting, and even fascinating in a
way, the responsibilities are so great that the effect on the nerves
is often very trying at times. One thing we are particular about, and
that is to take no chances. If we have the slightest doubt about the
genuineness of a check we at once communicate, either by telegraph,
special messenger, or telephone, with the supposed drawer of the
check, and in this way turn doubt into certainty. During the last
three years not a single wrong check has passed our vigilant optics,
and, though I say it who should not, I do not believe there is a
cleverer set of experts any where than those who compose my staff.

CHAPTER XIII

HOW TO DETERMINE AGE OF ANY WRITING

The Different Kinds of Ink Met With--Inks That Darken by Exposure to
Sunlight and Air--Introduction of Aniline Colors to Determine the Age
of Writings--An Almost Infallible Rule to Follow--To Determine
Approximate Age of Ink Possible--The Ammonia System a Sure One--A
Question of Great Interest to Bankers and Bank Employes--Thick Inks and
Thin Inks--So-called Safety Inks That Are Not Safe--How to Restore
Faded Inks--An Infallible Rule--Restoring Faded Writing--Restored by
the Silk and Cotton System That Anyone Can Arrange--Danger of Exposing
Restored Writing to the Sun.

The inks in common use over the United States at the present time,
and for some years past, are not as numerous as one might be led
to conclude. They are probably fifteen or at most twenty in all,
including the most popular blue, red, magenta, and green inks. But
among these there is a notable difference in character. Some are
thick, heavy, and glossy, in character, and flow sluggishly from the
pen. Few of these become much darker by standing. In this class will
be found the copying inks and those in which a large quantity of gums
or similar thickening agents are used.

Other inks are pale, limpid, and flow easily from the pen, and this
class usually shows a notable darkening by exposure to sunlight and
air. It will be unnecessary here to refer more particularly to the
intermediate varieties or to discuss their various composition.

It should be, remembered here that in the last twenty years, or since
the introduction into general commerce of aniline colors, which
Hofmann discovered in 1856, these latter