smelted in the far
interior. [230] Foreign iron is now used by the Battak of Sumatra,
but deserted iron-works are known to exist in their country, while the
Menangkabau still possess smelting furnaces. [231] It seems probable
that the whole industry had a common source, and was spread or carried
as a unit, but when trade relations made the arduous work of mining
and smelting unnecessary, it was quickly given up. That native iron
might have supplied the needs of many Philippine tribes, including
the Tinguian, is certain, for important deposits of magnetite and
hematite are found in Abra, in Ilocos Norte, Angat, Bulacan, Albay,
and other parts of the Islands. [232] On several occasions, when
on the trail, the natives have called our attention to boulders,
apparently of hematite, which they recognized as iron.

The smithies are small structures with grass roofs, but no sides or
floors (Plate LXII). At one end is a raised bamboo bench in front of
which stands the forge. This consists of two upright wooden cylinders,
usually logs hollowed out, known as _po-opan._ In each of these is
a piston or plunger (_doeydoyog_) at the lower end of which is a
wooden ring packed with corn husks and chicken feathers. When this
is pushed downward in the cylinder, it compresses the air and forces
it out of the small opening in the base, but when it is drawn up,
the packing collapses and allows the plunger to be raised without
effort. These pistons are worked so that one is rising, while the
other is falling. The cylinders stand in a wooden block out of which
bamboo tubes (_tolongon_) conduct the air into a tube of fire clay
(_ibong_), and this in turn carries it into the charcoal fire. There
are no valves, as in the Chinese bellows, but the bamboo tubes fit
loosely, and the fire is not drawn back. Near to the hearth is a stone
anvil (_dalisdisan_), while a heavy stone hammer, a small iron hammer,
and iron pinchers complete the outfit.

The fire is lighted, and the operator sitting on the bench alternately
raises and lowers the plungers in the cylinders until the fire burns
brightly; then the smith puts metal into the coals and allows it
to remain until it reaches a white heat. It is then removed and
placed on the anvil, where his helper beats it out with the large
hammer. This is a stone weighing twenty or more pounds, fitted inside
the handles so that it can be used with both hands. As a rule, it
is swung between the legs, and is allowed