have been out of employment,
haltingly return to their noble art. Portals and pillars and buttresses
and cornices are all covered with carven images of Our Lord and the
blessed Saints. The embroiderers too are set to work to make tapestries
for the walls. The jewellers offer their highest art that the shrine of
the altar may be worthy of complete adoration. Even the painter does his
best. Poor man, he is greatly handicapped by lack of a suitable medium.

And thereby hangs a story.

The Romans of the early Christian period had covered the floors and
the walls of their temples and houses with mosaics; pictures made of
coloured bits of glass. But this art had been exceedingly difficult.
It gave the painter no chance to express all he wanted to say, as all
children know who have ever tried to make figures out of coloured blocks
of wood. The art of mosaic painting therefore died out during the late
Middle Ages except in Russia, where the Byzantine mosaic painters
had found a refuge after the fall of Constantinople and continued
to ornament the walls of the orthodox churches until the day of the
Bolsheviki, when there was an end to the building of churches.

Of course, the mediaeval painter could mix his colours with the water
of the wet plaster which was put upon the walls of the churches. This
method of painting upon "fresh plaster" (which was generally called
"fresco" or "fresh" painting) was very popular for many centuries.
To-day, it is as rare as the art of painting miniatures in manuscripts
and among the hundreds of artists of our modern cities there is perhaps
one who can handle this medium successfully. But during the Middle Ages
there was no other way and the artists were "fresco" workers for lack
of something better. The method however had certain great disadvantages.
Very often the plaster came off the walls after only a few years, or
dampness spoiled the pictures, just as dampness will spoil the pattern
of our wall paper. People tried every imaginable expedient to get away
from this plaster background. They tried to mix their colours with wine
and vinegar and with honey and with the sticky white of egg, but none
of these methods were satisfactory. For more than a thousand years these
experiments continued. In painting pictures upon the parchment leaves of
manuscripts the mediaeval artists were very successful. But when it came
to covering large spaces of wood or stone with paint which would stick,
they did not