of the mode in which these singular mosaics
were produced, that the picture on one surface
was a reverse of that on the other: the
duck's head being to the right in the one and
to the left in the other.

True mosaic pictures are not common in
this country, being very expensive productions.
In an artistic point of view, too, there
is a limit to the excellence; for there must
necessarily be a certain hardness of outline,
unless the bits be almost infinitely small and
almost infinitely varied in colour. If a mosaic
be examined, all the separate bits will be
readily seen, joined by lines more or less
visible, according as the work is coarsely or
finely executed. Like a young lady's Berlin
pattern, the little squares are of many colours,
but each square is of one definite uniform
colour; indeed, we do not see why Berlin
work should not be honoured with the name
of mosaic.

The theory of little bits is as susceptible of
practical application with humble glass as
with imperial enamel. There is a substance
known as Keene's cement, which becomes as
hard as marble, and receives a polish very
little inferior to it. An ingenious artist has
contrived so to combine little bits of coloured
glass as to form a mosaic adornment to
articles fabricated in this cement; the white
polish of the cement and the coloured brilliancy
of the glass contrasting well with each other.
Productions of a very fanciful kind have in
this way been sent forth; one consists of a
pair of twisted columns upon pedestals, six or
seven feet high, and intended to hold lamps
or vases; the columns themselves are made
of the cement, and the glass mosaic is
introduced around the spiral shaft of the column
in bands of different patterns; while the
pedestal exhibits the mosaic in a geometrical
rather than an ornate style. The bits of
glass are imbedded in the cement while wet,
and the whiteness of the cement assists in
rendering apparent the colours of the mosaic.
It is evident that, if once this art should
tickle the fancy and open the purse of his
majesty, the public, an infinite variety of
applications would be forthcoming—to walls,
table-tops, chimney-pieces, pilasters, and so
forth. It must be admitted, however, that
this sort of mosaic is a very humble competitor
to that in enamel; it is upholsterer's mosaic
instead of artist's mosaic.

There is an elegant kind of mosaic or
inlaying practised by the Italians, and called by
them pietra dura, or hard stone. It consists
of little bits of pebble imbedded in a slab of
marble. The stone is really hard, for it
comprises such varieties as quartz, agate, jasper,
chalcedony, jade, cornelian, and lapis lazuli;
and the formation of these into a regular
pattern calls for the exercise of much patience
and ingenuity. The artist first takes a slab
of black marble, level in surface, and very
little exceeding an eighth of an inch in thickness;
he draws upon this the outline of his
design; he patiently cuts away the requisite
portions by means of files and saws; and he
has thus prepared the ground-work on which
his labours are to be afterwards bestowed.
He then attends to the pietra dura, the gems,
the little bits; every piece is, by lapidaries'
tools, cut to the exact size and form necessary
to fit it for the little vacuity which it is to
occupy; and all are thus adjusted until the
mosaic pattern is completed. The thin fragile
tablet thus prepared would never bear the
wear and tear of active service unless further
strengthened; it is on this account applied as
a veneer to a thicker slab of marble or other
stone. This is an extremely difficult art to
accomplish with any degree of success; for
in the imitation of natural objects, or in
anything beyond a mere geometrical design, it is
necessary to exercise great judgment in selecting
the colours of the stones, and in fashioning
each to a particular shape. The Florentine
artists are especially skilled in this
elegant art; they generally use pebbles picked
up on the banks of the Arno. The Russians
also show a fondness for these productions,
which they vary by applying the small
pebbles in relief on the surface of a slab; but
this is not properly mosaic—it is a sort of
stone-modelling in relievo, or it may deserve
the name of cameo-mosaic, which has been
given it. The jaspers and other pebbles,
found abundantly in Siberia, enable the
Russians to imitate various kinds of fruits
with surprising correctness, in this cameo-
mosaic. But the Hindoos excel both Florentines
and Russians in pietra dura work; their
designs are more elegant, and their workmanship
more minute and delicate.

If a variegated marble pavement be called
mosaic—which may be done by applying the
theory of little bits to big bits—then we have
many mosaics in England. But even here
the Italians beat us hollow; for that is a land
in which marble seems especially at home.
The pavement of our own St, Paul's Cathedral
shows how rich a design may be worked
out by this application of marble. The artist,
of course, sketches his design originally on
paper; and by giving to each piece of white
or grey or black marble the size corresponding
with the proper ratio, the design becomes
developed on the whole area of the pavement.

But there are other applications of marble,
approaching a little more nearly to the character
of mosaics. As the pattern is made smaller,
so can the details be made more delicate, more
pictorial, more approaching to a work of art.
Indeed, every one can see at a glance, that as
stone can be cut into very little bits, so can
these bits be combined in ornate or mosaic
forms. Derbyshire is a redoubtable workshop
for such productions, on account of the
numberless varieties of stone, marble, and spar
which it possesses; most of them very
readily cut. Devonshire is another of our
counties in which this mosaic art is practised.
Sometimes a pattern is cut, in intaglio, in a