472 



BOOK X. 



When the hour of eleven has struck, he sweeps up the charcoal ashes with 

 a broom and throws them out of the crucible. Then he climbs on to the 

 dome, and passing his hand in through its opening, and dipping an old linen 

 rag in a bucket of water mixed with ashes, he moistens the whole of the 

 crucible and sweeps it. In this way he uses two bucketsful of the mixture, 

 each holding five Roman sextarii,^^ and he does this lest the crucible, 

 when the metals are being parted, should break open ; after this he rubs the 

 crucible with a doe skin, and fills in the cracks. Then he places at the left side 

 of the channel, two fragments of hearth-lead, laid one on the top of the other, 

 so that when partly melted they remain fixed and form an obstacle, that the 

 litharge will not be blown about by the wind from the bellows, but remain in 

 its place. It is expedient, however, to use a brick in the place of the hearth- 

 lead, for as this gets much hotter, therefore it causes the litharge to form 

 more rapidly. The crucible in its middle part is made two palms and as 

 many digits deeper.^' 



There are some who having thus prepared the crucible, smear it over 

 with incense^", ground to powder and dissolved in white of egg, soaking 

 it up in a sponge and then squeezing it out again ; there are others who 

 smear over it a liquid consisting of white of egg and double the amount of 

 buUock's blood or marrow. Some throw lime into the crucible through a 

 sieve. 



Afterward the master of the works weighs the lead with which the gold 

 or silver or both are mixed, and he sometimes puts a hundred centumpondia^^ 

 into the crucible, but frequently only sixty, or fifty, or much less. After it 

 has been weighed, he strews about in the crucible three small bundles of 

 straw, lest the lead by its weight should break the surface. Then he places 

 in the channel several cakes of lead alloy, and through the aperture at the rear 

 of the dome he places some along the sides ; then, ascending to the opening at 

 the top of the dome, he arranges in the crucible round about the dome the 

 cakes which his assistant hands to him, and after ascending again and passing 

 his hands through the same aperture, he hkewise places other cakes inside the 

 crucible. On the second day those which remain he, with an iron fork, 

 places on the wood through the rear aperture of the dome. 



When the cakes have been thus arranged through the hole at the top of 

 the dome, he throws in charcoal with a basket woven of wooden twigs. Then 

 he places the lid over the dome, and the assistant covers over the joints with 

 lute. The master himself throws half a basketful of charcoal into the crucible 

 through the aperture next to the nozzle pipe, and prepares the bellows, in 

 order to be able to begin the second operation on the morning of the following 

 day. It takes the space of one hour to carry out such a piece of work, and 



**The Roman sextanus was about a pint. 



**This sentence continues, Ipsa vero media pars praeterea digito, to which we are unable 

 to attribute any meaning. 



^°Thus, or (us — " incense." 



"One centumpondium, Roman, equals about 70.6 lbs. avoirdupois; one centner, old 

 German, equals about 114. 2 lbs. avoirdupois. Therefore, if German weights are meant, the 

 maximum charge would be about 5.7 short tons ; if Roman weights, about 3.5 short tons. 



