BOOK XI. 503 



rotates with it ; therefore, when the axle revolves, the little axle and 

 the bronze tube in their turn raise the tooth and the stamp. When the 

 little iron axle and the bronze pipe have been taken out of the arms, the tooth 

 of the stamps is not raised, and other stamps may be raised without this one. 

 Further on, a drum with spindles fixed around the axle of a water-wheel 

 moves the axle of a toothed drum, which depresses the sweeps of the bellows 

 in the adjacent fourth part of the building ; but it turns in the contrary 

 direction ; for the axis of the drum which raises the stamps turns toward 

 the north, while that one which depresses the sweeps of the bellows turns 

 toward the south. 



Those cakes which are too thick to be rapidly broken by blows from 

 the iron-shod stamp, such as are generally those which have settled in the 

 bottom of the crucible,* are carried into the first part of the building. They 

 are there heated in a furnace, which is twenty-eight feet distant from the 

 second long wall and twelve feet from the second transverse wall. The three 

 sides of this furnace are built of rectangular rocks, upon which bricks are laid ; 

 the back furnace waU is three feet and a palm high, and the rear of the side 

 walls is the same ; the side walls are sloping, and where the furnace is open in 

 front they are only two feet and three palms high ; aU the walls are a foot and 

 a palm thick. Upon these walls stand upright posts not less thick, in order 

 that they may bear the heavy weight placed upon them, and they are covered 

 with lute ; these posts support the sloping chimney and penetrate through 

 the roof. Moreover, not only the ribs of the chimney, but also the rafters, 

 are covered thickly with lute. The hearth of the furnace is six feet 

 long on each side, is sloping, and is paved with bricks. The cakes of copper 

 are placed in the furnace and heated in the following way. They are first of 

 all placed in the furnace in rows, with as many smaU stones the size of an egg 

 between, so that the heat of the fire can penetrate through the spaces between 

 them ; indeed, those cakes which are placed at the bottom of the crucible are 

 each raised upon half a brick for the same reason. But lest the last row, 

 which hes against the mouth of the furnace, should fall out, against the mouth 

 are placed iron plates, or the copper cakes which are the first taken from the 

 crucible when copper is made, and against them are laid exhausted hquation 

 cakes or rocks. Then charcoal is thrown on the cakes, and then Uve coals ; 

 at first the cakes are heated by a gentle fire, and afterward more charcoal is 

 added to them until it is at times three-quarters of a foot deep. A fiercer fire 

 is certainly required to heat the hard cakes of copper than the fragile ones. 

 When the cakes have been sufficiently heated, which usually occurs within 

 the space of about two hours, the exhausted hquation cakes or the rocks 

 and the iron plate are removed from the mouth of the furnace. Then the 

 hot cakes are taken out row after row with a two-pronged rabble, such as the 

 one which is used by those who " dry " the exhausted hquation cakes. 

 Then the first cake is laid upon the exhausted liquation cakes, and beaten by 

 two workmen with hammers until it breaks ; the hotter the cakes are, the 



•By this expression is apparently meant the " bottoms " produced in enriching copper, 

 as described on p. 510. 



