SILVERING. 277 



wire, putting a little borax between. The pro- 

 portion of silver may be to that of the copper as 

 one to twelve. Put them into a white heat, when 

 the silver will be firmly fixed to the copper. Th;s 

 whole is now made to pass between rollers, till it 

 is of the required thickness for manufacturing 

 various articles. 



To make French Plate. 



Heat the copper articles intended to be plated, 

 and burnish silver-leaf on it, with a burnisher. 



To make Shell Silver. 



Grind up leaf-silver with gum-water or honey ; 

 when you have ground it, wash away the gum or 

 honey, and use the powder that remains with gum- 

 water, or glaire of eggs. This is laid on with a 

 hair-pencil. 



To silver Looking Glasses. 



The following apparatus must first be prepared. 



1. A square marble slab, or smooth stone, well 

 polished, and ground flat; the larger the better; 

 with a frame round it, or a groove cut in its edges, 

 to keep the superfluous mercury from running off. 



2. Lead weights, covered with cloth, to keep 

 them from scratching the glass; from one pound 

 weight to twelve pounds each, according to the 

 size of the glass which is laid down. 



3. Rolls of tinfoil. 



4. Quicksilver. 



Cut the tinfoil a little larger than the glass every 

 way, and lay it flat upon the stone; and with a 

 straight piece of hard wood, about three inches 



T 3 



