BOOK XI. 



515 



which turn five brass wheels, four of which are small, and the fifth much 

 larger than the rest. The notches in which the small wheels turn are two 

 palms long and as much as a palm wide ; those wheels are a palm wide and 

 a palm and two digits in diameter ; four of the notches are near the four 

 comers of the trolley ; the fifth notch is between the two front ones, and 

 it is two palms back from the front. Its pulley is larger than the rest, and 

 turns in its own notch ; it is three palms in diameter and one palm wide, 

 and grooved on the circumference, so that the iron chain may run in the 

 groove. The troUey has two small axles, to the one in front are fastened 

 three, and to the one at the back, the two wheels ; two wheels run on the 

 one beam of the crane-arm, and two on the other ; the fifth wheel, which is 

 larger than the others, runs between those two beams. Those people who 

 have no cranes place the cakes on a triangular board, to which iron cleats 

 are affixed, so that it will last longer ; the board has three iron chains, 

 which are fixed in an iron ring at the top ; two workmen pass a pole through 

 the ring and carry it on their shoulders, and thus take the cake to the furnace 

 in which silver is separated from copper. 



From the vicinity of the furnaces in which copper is mixed with lead and 

 the " slags " are re-melted, to the third long wall, are likewise ten furnaces, 

 in which silver mixed with lead is separated from copper. If this space is 

 eighty feet and two palms long, and the third long wall has in the centre a 

 door three feet and two palms wide, then the spaces remaining at either side 

 of the door will be thirty-eight feet and two palms ; and if each of the furnaces 

 occupies four feet and a palm, then the interval between each furnace and 

 the next one must be a foot and three palms ; thus the width of the five 

 furnaces and four interspaces will be twenty-eight feet and a palm. There- 

 fore, there remain ten feet and a palm, which measurement is so divided 

 that there are five feet and two digits between the first furnace and 

 the transverse wall, and as many feet and digits between the fifth furnace 

 and the door ; similarly in the other part of the space from the door to the 

 sixth furnace, there must be five feet and two digits, and from the tenth 

 furnace to the seventh transverse wall, hkewise, five feet and two digits. 

 The door is six feet and two palms high ; through it the foreman of the officina 

 and the workmen enter the store-room in which the silver-lead alloy is kept. 



Each furnace has a bed, a hearth, a rear wall, two sides and a front, 

 and a receiving-pit. The bed consists of two sole-stones, four rectangular 

 stones, and two copper plates ; the sole-stones are five feet and a palm 

 long, a cubit wide, a foot and a palm thick, and they are sunk into the ground, 

 so that they emerge a palm and two digits ; they are distant from each other 

 about three palms, yet the distance is narrower at the back than the front. 

 Each of the rectangular stones is two feet and as many palms long, a cubit 

 wide, and a cubit thick at the outer edge, and a foot and a palm thick on the 

 inner edge which faces the hearth, thus they form an incUne, so that there is a 

 slope to the copper plates which are laid upon them. Two of these rectang- 

 ular stones are placed on one sole-stone ; a hole is cut in the upper edge of 

 each, and into the holes are placed iron clamps, and lead is poured in ; they 



