varies much in
thickness and color. The first three cent stamp of the Danish West
Indies furnishes an instance of this. The stamps were sent from Denmark
without gum, as is frequently done with stamps for tropical countries.
When they reached the islands the stamps were given to two druggists to
be gummed. One used gum of good quality and, light color, while the
other used poor material and of so dark color as to stain the paper and
even darken the ink of the stamps. In Hanover rose-colored gum was used
for a number of issues. Some of the earliest local prints of the South
African Republic were made upon paper sent out ready gummed from
Germany. The paper was much wrinkled by the gum and the effect may be
seen in the wavy and broken lines of the ink.

The stamps of the first issue of Reunion were sold ungummed and were
affixed to letters in any way that pleased the writers. Some were
fastened by wafers and some even were pinned on.

Formerly, sheets of stamps to be gummed were fastened in a frame and the
gum applied by hand with a large brush. They were then sent to the
drying room and hung up to dry. Now the process is entirely mechanical.
The sheets are fed into a machine in which they first pass under a
gummed roller. Then they are carried on an endless chain through a long
box filled with steam pipes and emerge at the further end dry and ready
to be pressed and perforated.

The subject of perforations is also worthy of some brief attention. The
first stamps were imperforate, necessitating the use of scissors or
other instrument in separating them. This was a manifest inconvenience.
In 1847, Henry Archer, an Irishman, began experimenting with machines
for perforating stamps. After a number of attempts he succeeded in
making a machine which was accepted by the English government and for
which, in 1852, he was allowed a compensation of L4,000. James M. Napier
greatly improved on this machine and adapted it for steam power.

The general principle of all perforating machines is a series of hollow
needles, which remove rows of small disks of the paper from between the
stamps, and thus fit them to be readily torn apart. For convenience of
reference and description philatelists have adopted, as a standard of
measurement, the space of two centimetres. The gauge of a perforation is
determined by the number of holes in this distance. Scales have been
prepared for measuring perforations but it would be superfluous to
attem