For this purpose the operator will require the--

Plate Blocks,

Plate Vice

Spirit Lamp,

Polishing Buffs,

Nitric Acid, diluted in fifteen times its bulk of water

Galvanic Battery, to galvanize the plate, if it is too imperfect to be
used without, previous cleaning it, as directed in the last chapter.

Rottenstone,

Tripoli, which is too often dispensed with.

Rouge, or lampblack--the first being most preferable.
The English operators mix the two together.

Prepared cotton Wool, or Canton flannel. If the first is used,
it should be excluded from the dust, as it is not so easily
cleansed as the latter.

The plate is secured, with its silver side upward, to the block,
by the means described on page 58--having previously turned the edges
backward all around. The amount of cleaning a plate requires,
depends upon the state it is in. We will suppose one in the