TOL. XII.] PHILOSOPHICAL TRANSACTIONS. 4M 



middle, with two square knobs in the ends. Lastly, they give it other heatings 

 in the chafery, and more workings under the hammer, till they have brought it 

 into bars of several shapes and sizes, fit for sale. And if they omit any one 

 process, it will be sure to be deficient in toughness, which is accounted its per- 

 fection : though for several purposes, as for the backs of chimneys, hearths of 

 ovens, and the like, they have a sort of cast-iron, which they take out of the 

 receivers of the furnace in great ladles, and pour it into moulds of fine sand t 

 but this sort of iron is so very brittle, that being heated, with one blow of a 

 hammer it breaks all to pieces. 



The Method of making Cermse. By Sir Philiberto Femati. N° 137, P- 935. 



Pigs of clean and soft lead are cast into thin plates, a yard long, 6 inches 

 broad, and as thin as the back of a knife. These are artfully rolled round in 

 such a manner that the surfaces no where touch; for where they do, no cerusse 

 grows. — Thus rolled they are put each in a pot, just capable to hold one, sus- 

 tained by a little bar from the bottom, that it come not to touch the vinegar, 

 which is put into each pot, to effect the corrosion. — ^Next a square bed is made 

 of new horse-dung, large enough to hold 20 pots abreast, and so to make up 

 the number of 400 in one bed. — ^Then each pot is covered with a plate of lead ; 

 and lastly all with boards as close as possible. This repeated four times, makes 

 what is called one heap, containing l600 pots. 



After three weeks the pots are taken up, the plates unrolled, laid upon a 

 board, and beaten with battledoors till all the flakes come off: which if good, 

 prove thick, hard and weighty : if otherwise, fuzzy and light ; or sometimes 

 black and burned, if the dung prove not well ordered : and sometimes there 

 will be none. — From the beating-table the flakes are carried to the mill ; and 

 with water ground between millstones, until they be brought to almost an in- 

 palpable fineness. After which it is moulded into smaller parcels, and exposed 

 to the sun to dry, till it be hard, and so fit for use. 



Sometimes two pots alike ordered, and set one by each other, without any 

 possible distinction of advantage, shall yield the one thick and good flakes, the 

 other few and small or none. — Sometimes also the pots are taken up all dry, and 

 so prove then the best : sometimes again they are taken up wet. — It some- 

 times happens too that the plates that cover the pots yield better and thicker 

 flakes than the rolls within. And the outsides next to the planks larger and 

 better than the insides next to the rolls, and to the spirits that first arise from 

 the vinegar. 



The accidents happening to the workmen, are immediate pain in the stomach. 



