I mistook the title of the subject in thinking that it was mosaic only,
and at the last moment found it was marble and mosaic. However, the same
dominant principles shall underlie the treatment of marble. It is a
question of the finer instincts for form and color.

In recent years the demand for choice decorative materials has been the
means of opening out many marble quarries all over the world. Transit
being easy, a large scale of varieties is available. One fine addition
is the Mexican onyx. My feeling is that the most beautiful marbles are
those where the soft and sinuous veins melt and die into the general
body, comparatively sharp markings dying right away at the edges into
innumerable gradations. Marbles having strong and hardly marked veins
present great difficulties in distribution. If they are near, they
offend you with their coarseness; and, placed at a distance, the hard
vein lines have very little decorative value. I should say use these in
narrow slips, with very little moulded profile or as parts of intazzio.

Mouldings should be specially designed for different marbles. I should
say mainly on the principle of sudden contrasts; that is, large members
with very little curve bound with members very small in detail, thus
obtaining sharp lines, having little surface to be influenced or
distorted by the veined markings, and serving to sharpen up and give
form to the broader members (which show the color qualities of the
marble), much as you sharpen up an ink drawing by underlining. These
small members serve the architect's purpose for the expression of
vertical and horizontal lines, and where decisive and cutting shadows
are required in the composition of his work.

If delicate carving forms part of your design, I should say statuary is
the best, as you have no veins to distort your detail. I need hardly add