ention consists of a bed-plate
which rests on the floor and is secured in position by screw-jacks
braced against the roof and against the rib. On this bed-plate rests a
sliding frame which carries a revolving chain on which cutting tools
are fixed. The machine carries its own motor, which not only drives
the chain, but also slides forward the frame into the cut. When the
cut is made to the full depth of the machine, it is withdrawn, and the
machine moved over its own width and another cut commenced. Several of
these machines were at work in the mine, but chiefly in that part of
it where the pillars were being cut away, and where speed in removing
the coal was a prime necessity. In the more distant rooms, hand labor
was used.

All these machines work on exactly the same principle as that of the
miner, lying on his back or on his side, and digging at the coal with
his pick. The coal must be undercut as far in as a pick or a
mechanical coal-cutter will reach, for the entire width of the face.
Every few feet, short props or sprags are put in from the edge of the
undermined portion to the floor, to prevent a premature fall, which
might bury the miner.

When the whole face is undercut and spragged, the shot-firer is
summoned. One or more holes, three feet deep, are bored in the coal,
close to the roof, these holes are filled with explosive and tamped
shut with moist clay, and the charges are fired. This blasting brings
down the coal off the face, clear from the rock roof to the undermined
portion, for such a distance as it has been undercut.

The miner then shovels away the coal far enough to allow him to lie
down again and continue his terribly laborious task, while the loader
comes and shovels the blasted coal into cars or into endless-chain
conveyors, according to the arrangement of the mine.

Day in, day out, this hewing continues. While the miner is at work, he
is always in a cramped position, his body twisted, his muscles at a
strain, performing his toilsome labor in the half-dark, in the heat,
in poor air, choked with coal-dust constantly and menaced by death
every moment. He is well paid, but most fully does he earn every cent
he gets.

The morning had almost passed, and Anton was near the entry, where he
heard, in the distance, a dull rumble like thunder, followed by a
queer cracking sound which seemed to travel along the rock overhead.

The boy halted involuntarily in his task of pushing an empty car back
to