The smithies are about 12 feet square without side walls.  They have a grass roof sloping to within 3 feet of the earth, enlarging the shaded area to near 20 feet square.  Near one side of the room is the bellows, called “op-op’,” consisting of two vertical, parallel wooden tubes about 5 feet long and 10 inches in diameter, standing side by side.  Each tube has a piston or plunger, called “dot-dot’;” the packing ring of the piston is of wood covered with chicken feathers, making it slightly flexible at the rim, so it fits snugly in the tube.  The lower end of the bellows tubes rests in the earth, 4 inches above which a small bamboo tube leads the compressed air to the fireplace from each bellows tube.  These small tubes, called “to-bong’,” end near an opening through a brick at the back of the fire, and the air forced through them passes on through the brick to the burning charcoal.  The outer end of the to-bong’ is cut at an angle, and as the tubes end outside the opening in the brick, the air inbreathed by the bellows, as the plungers are raised, is drawn from back of the fireplace —­ thus the fire is not disturbed.

The fuel is an inferior charcoal prepared by the Igorot from pine.  This bellows is found throughout the Archipelago and is evidently a Malayan product.  It is believed that it came to Bontoc with the Igorot from their earlier home and is not, as some say, a Chinese invention.[29] The Igorot manufacturer of metal pipes uses exactly the same kind of bellows, except that it is very much smaller, and so appears like a toy.  It is poorly shown in Pl.  CIX.

Much of the iron now employed in the manufacture of Igorot weapons is Chinese bar iron coming from China to the Islands at Candon, in Ilokos Sur.  However, the people readily make weapons from any iron they may acquire, greatly preferring the scraps of broken Chinese cast-iron pots, vessels purchased primarily for making sugar.  In his choice of cast iron the Igorot exhibits a practical knowledge of metallurgy, since cast iron makes better steel than wrought iron —­ that is, as he has to work.

FIGURE 5

Ironsmith’s stone hammer.

The anvils of the smithy, numbering four or five, are large rocks set solidly in the earth.  The hammers are nearly all stone, though some of the workmen have a small iron hammer used in finishing the weapons.

There are several varieties of stone hammers.  One weighing about 30 pounds is 16 inches long, 10 inches wide, and from 4 to 6 inches thick.  An inch-deep groove is cut in both edges of the hammer, and into these grooves the short, double wooden handle is attached by a withe.  Another hammer, similar to the above in shape and attachment, is about one-third its size and weight.  There is a still smaller hammer lashed with leather bands to a single, straight wooden handle; and there is also a round hammer stone about 3 inches in diameter without handle or attachment, which hammer, together with the larger one last mentioned, is largely superseded in some of the smithies by the metal hammer.