1closed.
The bellows, by the first method, blows fresh air into the conduit
through its nozzle, and by the second method blows out through the nozzle
the heavy and pestilential vapours which have been collected. In this
latter case fresh air enters through the larger part of the shaft, and the miners
getting the benefit of it can sustain their toil. A certain smaller part of the
shaft which forms a kind of estuary, requires to be partitioned off from the
other larger part by uninterrupted lagging, which reaches from the top of the
shaft to the bottom; through this part the long but narrow conduit reaches
down nearly to the bottom of the shaft.
through its nozzle, and by the second method blows out through the nozzle
the heavy and pestilential vapours which have been collected. In this
latter case fresh air enters through the larger part of the shaft, and the miners
getting the benefit of it can sustain their toil. A certain smaller part of the
shaft which forms a kind of estuary, requires to be partitioned off from the
other larger part by uninterrupted lagging, which reaches from the top of the
shaft to the bottom; through this part the long but narrow conduit reaches
down nearly to the bottom of the shaft.
When no shaft has been sunk to such depth as to meet a tunnel driven
far into a mountain, these machines should be built in such a manner that
the workman can move them about. Close by the drains of the tunnel
through which the water flows away, wooden pipes should be placed and
joined tightly together in such a manner that they can hold the air; these
should reach from the mouth of the tunnel to its furthest end. At the mouth
of the tunnel the bellows should be so placed that through its nozzle it can
blow its accumulated blasts into the pipes or the conduit; since one blast
far into a mountain, these machines should be built in such a manner that
the workman can move them about. Close by the drains of the tunnel
through which the water flows away, wooden pipes should be placed and
joined tightly together in such a manner that they can hold the air; these
should reach from the mouth of the tunnel to its furthest end. At the mouth
of the tunnel the bellows should be so placed that through its nozzle it can
blow its accumulated blasts into the pipes or the conduit; since one blast
A—TUNNEL. B—PIPE. C—NOZZLE OF DOUBLE BELLOWS.