In hosiery presses, printers' arming presses, and many others, the top
plate also requires to be heated. The best way to do this is to use a
number of blowpipe flames directed downward. In many cases the supply
of air under pressure is a practical difficulty and objection. This is
overcome, to a certain extent, by the use of a thick upper plate with a
number of horizontal holes, into which a Bunsen flame is directed. In
every case I have seen, without one single exception, the holes are
either too small, or the burner is placed too close, and the consequence
is that the gas, instead of burning inside the holes, as it should,
passes through partially unburnt, and is consumed at the opposite end,
where it is absolutely useless, the flame not being in contact with or
under the surface to be heated, and therefore doing no work. In hosiery
presses this is a great objection, as the holes are so long that an
equal heat is simply impossible, and the only remedy is to use a
blowpipe flame, which forces sufficient air in with the gas to insure
combustion where the heat is necessary.
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