6.--Gilding: or covering the picture with a thin film of gold--
which not only protects it, but greatly improves its distinctness
and tone of color.

7.--Coloring the picture.

For these various operations the following articles--
which make up the entire apparatus of a Daguerrean artist--
must be procured

1.--THE CAMERA.--(Fig. 5.). The Camera Obscura of the Italian
philosophers, although highly appreciated, on account of the magical
character of the pictures it produced, remained little other
than a scientific toy, until the discovery of M. Daguerre.
The value of this instrument is now great, and the interest of
the process which it so essentially aids, universally admitted.
A full description of it will therefore be interesting.
[hipho_5.gif]

The camera is a dark box (a), having a tube with lenses (b) placed
in one end of it, through which the radiations from external
objects pass, and form a diminished picture upon the ground glass
(g) placed at the proper distance in the box to receive it;
the cap c covering the lenses at b until the plate is ready
to receive the image of the object to be copied.

Thus a (fig. 6.) representing the lens, and b the object desired to
be represented, the rays (c, c) proceeding from it fall upon the lens,
and are transmitted to a point, which varies with the curvature of
the glass, where an inverted image (d) of b is very accurately formed.