226 BOOK VII. 



holes, the ashes from the burning charcoal, as I have stated, fall down, and 

 air blows into the furnace after passing through the openings in the walls of 

 the chamber. The furnace is rectangular, and inside at the lower part it is 

 three palms and one digit wide and three palms and as many digits long. At 

 the upper part it is two palms and three digits wide, so that it also grows 

 narrower ; it is one foot high ; in the middle of the back it is cut out at 

 the bottom in the shape of a semicircle, of half a digit radius. Not 

 unlike the furnace before described, it has in its forepart a mouth which is 

 rounded at the top, one palm high and a palm and a digit wide. Its door 

 is also made of clay, and this has a window and a handle ; even the lid 

 of the furnace which is made of clay has its own handle, fastened on with iron 

 wire. The outer parts and sides of this furnace are bound with iron wires, 

 which are usually pressed in, in the shape of triangles. The brick furnaces 

 must remain stationary ; the clay and iron ones can be carried from one 

 place to another. Those of brick can be prepared more quickly, while those 

 of iron are more lasting, and those of clay are more suitable. Assay ers 

 also make temporary furnaces in another way ; they stand three bricks 

 on a hearth, one on each side and a third one at the back, the fore-part lies 

 open to the draught, and on these bricks is placed an iron plate, upon which 

 they again stand three bricks, which hold and retain the charcoal. 



The setting of one furnace differs from another, in that some are placed 

 higher and others lower ; that one is placed higher, in which the man who is 

 assaying the ore or metals introduces the scorifier through the mouth with the 

 tongs ; that one is placed lower, into which he introduces the crucible 

 through its open top. 



In some cases the assay er uses an iron hoop 4 in place of a furnace ; 

 this is placed upon the hearth of a chimney, the lower edge being daubed 

 with lute to prevent the blast of the bellows from escaping under it. 

 If the blast is given slowly, the ore will be smelted and the copper will melt in 

 the triangular crucible, which is placed in it and taken away again with the 

 tongs. The hoop is two palms high and half a digit thick ; its diameter is 

 generally one foot and one palm, and where the blast from the bellows enters 

 into it, it is notched out. The bellows is a double one, such as goldworkers 

 use, and sometimes smiths. In the middle of the bellows there is a board in 

 which there is an air-hole, five digits wide and seven long, covered by a 

 little flap which is fastened over the air-hole on the lower side of the board ; 

 this flap is of equal length and width. The bellows, without its head, is 

 three feet long, and at the back is one foot and one palm wide and 

 somewhat rounded, and it is three palms wide at the head ; the head itself 

 is three palms long and two palms and a digit wide at the part where it joins 

 the boards, then it gradually becomes narrower. The nozzle, of which there 

 is only one, is one foot and two digits long ; this nozzle, and one-half of the 

 head in which the nozzle is fixed, are placed in an opening of the wall, this 

 being one foot and one palm thick ; it reaches only to the iron hoop on the 



*Circulu$. This term does not offer a very satisfactory equivalent, as such a furnace 

 has no distinctive name in English. It is obviously a sort of forge for fusing in crucibles. 



