BOOK XI.

53i

these furnaces occupies thirteen feet, the space which is on the rightside of the first furnace, and on the left of the fourth, are each three feet andthree palms wide, and the distance between the second and third furnace issix feet. In the middle of each of these three spaces is a door, a foot anda half wide and six feet high, and the middle one is common to the masterof each of the furnaces. Each furnace has its own chimney, which risesbetween the two long walls mentioned above, and is supported by two archesand a partition wall. The partition wall is between the two furnaces, andis five feet long, ten feet high, and two feet thick; in front of it is a pillarbelonging in common to the front arches of the furnace on either side, whichis two feet and as many palms thick, three feet and a half wide. The frontarch reaches from this common pillar to another pillar that is common to theside arch of the same furnace; this arch on the right spans from the secondlong wall to the same pillar, which is two feet and as many palms wide andthick at the bottom. The interior of the front arch is nine feet and a palmwide, and eight feet high at its highest point; the interior of the arch whichis on the right side, is five feet and a palm wide, and of equal height to theother, and both the arches are built of the same height as the partition wall.Imposed upon these arches and the partition wall are the walls of the chimney;these slope upward, and thus contract, so that at the upper part, where thefumes are emitted, the opening is eight feet in length, one foot and threepalms in width. The fourth wall of the chimney is built vertically upon thesecond long wall. As the partition wall is common to the two furnaces, so itssuperstructure is common to the two chimneys. In this sensible mannerthe chimney is built. At the front each furnace is six feet two palms long,and three feet two palms wide, and a cubit high; the back of each furnaceis against the second long wall, the front being open. The first furnace is openand sloping at the right side, so that the slags may be drawn out; the leftside is against the partition wall, and has a little wall built of bricks cementedtogether with lute; this little wall protects the partition wall from injury bythe fire. On the contrary, the second furnace has the left side open andthe right side is against the partition wall, where also it has its own little wallwhich protects the partition wall from the fire. The front of each furnace isbuilt of rectangular rocks ; the interior of it is filled up with earth. Then ineach of the furnaces at the rear, against the second long wall, is an aperturethrough an arch at the back, and in these are fixed the copper pipes. Eachfurnace has a round pit, two feet and as many palms wide, built three feetaway from the partition wall. Finally, under the pit of the furnace, at adepth of a cubit, is the hidden receptacle for moisture, similar to the others,whose vent penetrates through the second long wall and slopes upward tothe right from the first furnace, and to the left from the second. If copperis to be made the next day, then the master cuts out the crucible with aspatula, the blade of which is three digits wide and as many palms long, theiron handle being two feet long and one and a half digits in diameter; thewooden handle inserted into it is round, five feet long and two digitsin diameter. Then, with another cutting spatula, he makes the crucible