156
THE POPULAR SCIENCE MONTHLY.
and others (3 and 4) are removing, by means of levers and rollers, the sow last made. The wooden bellows which blow the furnace are shown at R, R, R. The furnace illustrated appears to have been constructed with unusual care, its walls having been
Fig. 5.—Preparing to cast a sow.
built of dressed stone laid in regular courses, strengthened at the corners by massive rampant arched buttresses, one of which is marked Z, Z. At B, B, B, are iron bearers that support the masonry of the furnace above the arch; C, C, are side stones of the hearth; D is the "tymp"; F, the "dam"; I, the "tap-hole."
