[ i68 ] 



or miftake is committed, and when dry may 

 worked over again to redtify a miftake. Thq 

 piece Ihould be thoroughly examined, and all 

 omiffions redified, before the Aqua fortis is ap- 

 plied to the plate. 



A fofi Wax/i?r hrdering the Plate to keep on the^ 

 Aaua fortis. 



Take white rofin and bees-wax in equal parts, 

 incorporate them together over a fire in a pip- 

 kin, and make the mixture into a roll for ufe. 

 If it be found too hard to be worked and knead- 

 ed with your hands in winter, it may be brought 

 to a greater or iefs degree of foftnefs, by melting 

 it again, with a Iefs or greater proportion of 

 olive oil. 



When your plate an^d the wax are ready, take 

 a piece of the wax, wet your hands, and roll the 

 wax out in length like a cord, fufficient to go 

 round the borders of your plate j then lay your 

 plate in an horizontal pofition, where it may lie 

 firm 5 then fix your wax on its edges very clofe, 

 that the Aqua fortis may not pafs betweea thç 



wax 



