Although we now tend to refer to the various crafts according to the materials used to construct
them-clay
, glass, wood, fiber, and metal-it was once common to think of crafts in terms of function,
which led to their being known as the "applied arts." Approaching crafts from the point of view
of function
, we can divide them into simple categories: containers, shelters and supports. There is no way
around
the fact that containers, shelters, and supports must be functional. The applied arts are
thus bound by the
laws of physics, which pertain to both the materials used in their making and the substances
and things to
be contained, supported, and sheltered. These laws are universal in their application,
regardless of cultural beliefs, geography, or climate. If a pot has no bottom or has large openings
in its
sides, it could hardly be considered a container in any traditional sense. Since the laws of
physics
, not
some arbitrary decision, have determined the general form of applied-art objects, they follow basic
patterns,
so much so that functional forms can vary only within certain limits. Buildings without roofs,
for example, are unusual because they depart from the norm. However, not all functional objects are
exactly alike; that is why we recognize a Shang Dynasty vase as being different from an Inca vase.
What varies is not the basic form but the incidental details that do not obstruct the object's
primary
function.
Sensitivity to physical laws is thus an important consideration for the maker of applied-art
objects.
It is often taken for granted that this is also true for the maker of fine-art objects. This
assumption
misses a significant difference between the two disciplines. Fine-art objects are not
constrained by
the laws of physics in the same way that applied-art objects are. Because their
primary purpose is
not functional, they are only limited in terms of the materials used to make them.
Sculptures must,
for example, be stable, which requires an understanding of the properties of mass,
weight distribution,
and stress. Paintings must have rigid stretchers so that the canvas will be taut, and
the paint must not
deteriorate, crack, or discolor. These are problems that must be overcome by the artist
because they
tend to intrude upon his or her conception of the work. For example, in the early
Italian Renaissance,
bronze statues of horses with a raised foreleg usually had a cannonball under that hoof.
This was done
because the cannonball was needed to support the weight of the leg. In other words, the demands
of the laws of physics, not the sculptor's aesthetic intentions, placed the ball there.
That this device
was a necessary structural compromise is clear from the fact that the cannonball quickly disappeared
when sculptors learned how to strengthen the internal structure of a statue
with iron braces (iron being
much stronger than bronze).