The illustration shows a hot table suitable for use in silvering glass; it has the middle slate removed. One-inch board should be used for the top of the table, the slate top S being 1 1/2 in. thick. The inside should be lined with zinc to make it airtight, the zinc being brought over the side. The slate slab should be bedded in red-lead, all joints being filled with red-lead mixed with varnish. The table must be quite level. A blanket or piece of felt should be placed over the slate when in use, and made wet with water before the steam is used. Steam should be turned on gradually by a valve at I; the hotter the table the quicker the silver will deposit. The outlet pipe O for steam is absolutely necessary, and could be regulated by a valve, as the confined steam would lift off the slate. The outlet pipe should be led to a convenient place so as not to interrupt a clear passage round the table. The pipe W in the bottom of the table is to let out the water formed by the condensing of the steam. The zinc is turned into the groove G, which is also for the bed of red lead. The glass to be silvered must be chemically clean, and whilst still wet from the washing it should be placed on the hot table and have a solution of gelatine or other mordant poured over it.

Before this hardens, cover the glass with a saturated solution of nitrate of silver, and allow to remain untouched for about ten minutes. After wiping with a leather squeegee, again apply the silver nitrate solution, and complete the process by a final wiping with the squeegee.

Table for Silvering Plate Glass.