5i8 BOOK XI. 



the back one of which is round and a digit in diameter, and in this is engaged 

 the first Hnk of the chain as I have stated ; the hole at the front end is two 

 digits and a half long and a digit and a half wide. This end of each rod 

 is made three digits wide, while for the rest of its length it is only two digits, 

 and at the back it is two and a half digits. Into the front hole of each rod is 

 driven an iron bar, which is three feet and two palms long, two digits wide 

 and one thick ; in the end of this bar are five small square holes, two-thirds 

 of a digit square ; each hole is distant from the other half a digit, the first 

 being at a distance of about a digit from the end. Into one of these holes the 

 refiner drives an iron pin ; if he should desire to make the furnace narrower, 

 then he drives it into the last hole ; if he should desire to widen it, then into 

 the first hole ; if he should desire to contract it moderately, then into one 

 of the middle holes. For the same reason, therefore, the hook is sometimes 

 inserted into the last link of the chain, and sometimes into the third or the 

 second. The furnace is widened when many cakes are put into it, and con- 

 tracted when there are but few, but to put in more than five is neither usual 

 nor possible ; indeed, it is because of thin cakes that the walls are contracted. 

 The bar has a hump, which projects a digit on each side at the back, of the 

 same width and thickness as itself. These humps project, lest the bar should 

 slip through the hole of the right-hand rod, in which it remains fixed when 

 it, together with the rods, is not pressing upon the furnace walls. 



There are three panels to the furnace — two at the sides, one in front 

 and another at the back. Those which are at the sides are three feet 

 and as many palms and two digits long, and two feet high ; the front one is 

 two feet and a palm and three digits long, and, like the side ones, two feet 

 high. Each consists of iron bars, of feet, and of iron plates. Those which are 

 at the side have seven bars, the lower and upper of which are of the same 

 length as the panels ; the former holds up the upright bars ; the latter is 

 placed upon them ; the uprights are five in number, and have the same height 

 as the panels ; the middle ones are inserted into holes in the upper and lower 

 bars ; the outer ones are made of one and the same bar as the lower and 

 upper ones. They are two digits wide and one thick. The front panel has 

 five bars ; the lower one holds similar uprights, but there are three of them 

 only ; the upper bar is placed on them. Each of these panels has two feet 

 fixed at each end of the lower bar, and these are two palms long, one wide, 

 and a digit thick. The iron plates are fastened to the inner side of the bars 

 with iron wire, and they are covered with lute, so that they may last longer 

 and may be uninjured by the fire. There are, besides, iron blocks three palms 

 long, one wide, and a digit and a half thick ; the upper surface of these is 

 somewhat hollowed out, so that the cakes may stand in them ; these iron 

 blocks are dipped into a vessel in which there is clay mixed with water, and 

 they are used only for placing under the cakes of copper and lead alloy made 

 in the furnaces. There is more silver in these than in those which are 

 made of hquation thorns, or furnace accretions, or re-melted " slags." Two 

 iron blocks are placed under each cake, in order that, by raising it up, the fire 

 may bring more force to bear upon it ; the one is put on the right bed-plate. 



