the various manufacturers. Cotton hose is woven through
machines expressly designed for that purpose, and afterward has a
half-cured rubber tube drawn through it. One end is then securely
stopped up and the other end forced on a cone through which steam is
introduced to the inside of the hose, forcing the rubber against the
cotton cover, finishing the cure and fixing it firmly in its place.

CORRUGATED MATTING.

After the mixing of the compound and the calendering, that is the
spreading it in sheets, the great roll of rubber and cloth that is to
be made into corrugated matting is sent to the pressman. Here it is
hung in a rack and fifteen or twenty feet of it drawn between the
plates of the huge hydraulic steam press. The bottom plate of this
press is grooved its whole length, so that when the upper platen is
let down the plain sheet of rubber is forced into the grooves and the
corrugations are formed. While in that position steam is let into the
upper and lower platens and the matting is cured. After it has been in
there the proper time, cold water is let into the press, it is cooled
off, and the upper platen being raised, it is ready to come out. A
simple device for loosening the matting from the grooves into which it
has been forced is a long steel rod, with a handle on one hand like an
auger handle, which, being introduced under the edge and twisted,
allows the air to enter with it and releases it from the mould.

PACKING.

Sheet packing is often times made in a press, like corrugated matting.
The varieties, however, known as gum core have to go through a
different process. Usually a core is squirted through a tube machine
and the outside covering of jute or cotton, or whatever the fabric may
be, is put on by a braider or is wrapped about it somewhat after the
manner of the old fashioned cloth-wrapped tubing. The fabric is either
treated with some heat-resisting mixture or something that is a
lubricant, plumbago and oil being the compound. Other packings are
made from the ends of belts cut out in a circular form and treated
with a lubricant. There are scores of styles that make special claims
for excellences that are made in a variety of ways, but as a rule the
general system as outlined above is followed.

JAR RINGS.

The old fashioned way of making jar rings was first to take a large
mandrel and wrap it around with a sheet of compounded rubber until the
thickness of the ring was secured. It was then