his planes in
perspective, has treated them separately, and placed them one above the
other. We find the same disposition of the parts in all Egyptian tomb
paintings. Scenes of inundation and civil life are ranged along the base of
the wall, mountain subjects and hunting scenes being invariably placed high
up. Sometimes, interposed between these two extremes, the artist has
introduced subjects dealing with the pursuits of the herdsman, the field
labourer, and the craftsman. Elsewhere, he suppresses these intermediary
episodes, and passes abruptly from the watery to the sandy region. Thus,
the mosaic of Palestrina and the tomb-paintings of Pharaonic Egypt
reproduce the same group of subjects, treated after the conventional styles
and methods of two different schools of art. Like the mosaic, the wall
scenes of the tomb formed, not a series of independent scenes, but an
ordinary composition, the unity of which is readily recognised by such as
are skilled to read the art-language of the period.

2.--TECHNICAL PROCESSES.

[Illustration: Fig. 178.--Sculptor's sketch from Ancient Empire tomb.]

[Illustration: Fig. 179.--Sculptor's sketch from Ancient Empire tomb.]

The preparation of the surface about to be decorated demanded much time and
care. Seeing how imperfect were the methods of construction, and how
impossible it was for the architect to ensure a perfectly level surface for
the facing stones of his temple-walls and pylons, the decorator had
perforce to accommodate himself to a surface slightly rounded in some
places and slightly hollowed in others. Even the blocks of which it was
formed were scarcely homogeneous in texture. The limestone strata in which
the Theban catacombs were excavated were almost always interspersed with
flint nodules, fossils, and petrified shells. These faults were variously
remedied according as the decoration was to be sculptured or painted. If
painted, the wall was first roughly levelled, and then overlaid with a coat
of black clay and chopped straw, similar to the mixture used for brick-
making. If sculptured, then the artist had to arrange his subject so as to
avoid the inequalities of the stone as much as possible. When these
occurred in the midst of the figure subjects, and if they did not offer too
stubborn a resistance to the chisel, they were simply worked over;
otherwise the piece was cut out and a new piece fitted in, or the hole was
filled up with white cement. This mendi