58o BOOK XII. 



of the same size and shape, and without a spout, but having three holes, two of 

 which are below the mouth and receive the spouts of the two first pots ; the 

 third hole is on the opposite side at the bottom, and through it the sulphur 

 flows out. In each furnace are placed two pots with spouts, and the furnace 

 must be covered by plates of iron smeared over with lute two digits thick ; it is 

 thus entirely closed in, but for two or three ventholes through which the mouths 

 of the pots project. Outside of the furnace, against one side, is placed the pot 

 without a spout, into the two holes of which the two spouts of the other pots 

 penetrate, and this pot should be built in at both sides to keep it steady. When 

 the sulphur ore has been placed in the pots, and these placed in the furnace, 

 they are closely covered, and it is desirable to smear the joint over with lute, 

 so that the sulphur will not exhale, and for the same reason the pot below is 

 covered with a lid, which is also smeared with lute. The wood having been 

 kindled, the ores are heated until the sulphur is exhaled, and the vapour, 

 arising through the spout, penetrates into the lower pot and thickens into 

 sulphur, which falls to the bottom like melted wax. It then flows out 

 through the hole, which, as I said, is at the bottom of this pot ; and the work- 

 man makes it into cakes, or thin sticks or thin pieces of wood are dipped in it. 

 Then he takes the burning wood and glowing charcoal from the furnace, and 

 when it has cooled, he opens the two pots, empties the residues, which, if the 

 ores were composed of sulphur and earth, resemble naturally extinguished 

 ashes ; but if the ores consisted of sulphur and earth and stone, or sulphur 

 and stone only, they resemble earth completely dried or stones well roasted. 

 Afterward the pots are re-filled with ore, and the whole work is repeated. 



The sulphurous mixture, whether it consists of stone and sulphur only, 

 or of stone and sulphur and metal, may be heated in similar pots, but with 

 perforated bottoms. Before the furnace is constructed, against the " second " 

 wall of the works two lateral partitions are built seven feet high, three feet 

 long, one and a half feet thick, and these are distant from each other twenty- 

 seven feet. Between them are seven low brick walls, that measure but 

 two feet and the same number of digits in height, and, like the other walls, 

 are three feet long and one foot thick ; these little walls are at equal 

 distances from one another, consequently they will be two and one half feet 

 apart. At the top, iron bars are fixed into them, which sustain iron plates 

 three feet long and wide and one digit thick, so that they can bear not only 

 the weight of the pots, but also the fierceness of the fire. These plates have 

 in the middle a round hole one and a half digits wide ; there must not be 

 more than eight of these, and upon them as many pots are placed. These 

 pots are perforated at the bottom, and the same number of whole pots are 

 placed underneath them ; the former contain the mixture, and are covered 

 with lids ; the latter contain water, and their mouths are under the holes 

 in the plates. After wood has been arranged round the upper pots and 

 ignited, the mixture being heated, red, yellow, or green sulphur drips 

 from it and flows down through the hole, and is caught by the pots placed 

 underneath the plates, and is at once cooled by the water. If the mixture 

 contains metal, it is reserved for smelting, and, if not, it is thrown away. 



