482 



BOOK X. 



In certain places, as at Freiberg in Meissen, the upper part of the 

 cupellation furnace is vaulted almost like an oven. This chamber is four 

 feet high and has either two or three apertures, of which the first, in 

 front, is one and a half feet high and a foot wide, and out of this flows 

 the litharge ; the second aperture and likewise the third, if there be three, 

 are at the sides, and are a foot and a half high and two and a half feet wide, 

 in order that he who prepares the crucible may be able to creep into the 

 furnace. Its circular bed is made of cement, it has two passages two feet high 

 and one foot wide, for letting out the vapour, and these lead directly through 

 from one side to the other, so that the one passage crosses the other at right 

 angles, and thus four openings are to be seen ; these are covered at the top 

 by rocks, wide, but only a palm thick. On these and on the other parts 

 of the interior of the bed made of cement, is placed lute mixed with straw, 

 to a depth of three digits, as it was placed over the sole and the plates of 

 copper and the rocks of that other furnace. This, together with the ashes which 

 are thrown in, the master or the assistant, who, upon his knees, prepares 

 the crucible, tamps down with short wooden rammers and with mallets 

 likewise made of wood. 



NMp^ 



A FURNACE SIMILAR TO AN OVEN. B PASSAGE. C IRON BARS. D HOLE THROUGH 



WHICH THE LITHARGE IS DRAWN OUT. E CRUCIBLE WHICH LACKS A DOME. F THICK 



STICKS. G BELLOWS 



