To cut these off separately is quite
impossible, but they are easily removed by passing the muslin
rapidly over a cylinder of iron kept at a dull red heat: the time
during which each portion of the muslin is in contact with the
red-hot iron is too short to heat it to the burning point; but
the filaments being much finer, and being pressed close to the
hot metal, are burnt.
The removal of these filaments from patent net is still more
necessary for its perfection. The net is passed at a moderate
velocity through a flame of gas issuing from a very long and
narrow slit. Immediately above the flame a long funnel is fixed,
which is connected with a large air-pump worked by a
steam-engine. The flame is thus drawn forcibly through the net,
and all the filaments on both sides of it are burned off at one
operation. Previously to this application of the air-pump, the
net acting in the same way, although not to the same extent, as
the wire-gauze in Davy's safety lamp, cooled down the flame so as
to prevent the combustion of the filaments on the upper side: the
air-pump by quickening the current of ignited gas, removes this
inconvenience.
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