on claims; the fewer the elements
recited, the stronger will the claim be; non-essential elements weaken
or destroy the claim; the claim should not be considered satisfactory
so long as a way is seen for the escape of the ingenious pirate.

COMBINATIONS AND AGGREGATIONS.

A given association of mechanical elements may be entirely new, but it
does not follow that it forms a patentable association, for not all
new things are patentable. If the new association is a combination, it
is patentable, but if it is a mere aggregation, it is unpatentable. An
association may be new and still all of its separate elements may be
old, the act of invention lying in the fact that the elements have
been so associated with relation to each other as to bring about an
improved result, or an improved means for an old result. All new
machines are, after all, composed of old elements. The law presupposes
that the elements are old, and that the invention resides in the
peculiar association of them. If we take a given mechanical element,
recognized as having had a certain capacity, and if we then similarly
take some other mechanical element and employ it only for its
previously recognized capacity, and if we then add the third element
for its recognized capacity, we have in the end only an association of
three elements each performing its well recognized individual office,
and the entire association performing only the sum of the recognized
individual elements. Such an association is a mere aggregation, a mere
adding together of elements, without making the sum of the results any
greater in the association than it was in the individual elements. It
is simply adding two to one and getting three as a result. An
aggregation is unpatentable. As an illustration, a heavy marble statue
of Jupiter is found in the parlor and difficult to move. Ordinary
casters are put under its pedestal and it becomes easier to move.
Modern anti-friction two-wheeled casters are substituted for the
commoner casters, and the statue becomes still easier to move. Casters
were never before associated with a statue of Jupiter. Here is a new
association, but it is a mere aggregation. The statue of Jupiter has
been unmodified by the presence of the casters, and the casters
perform precisely the same under the statue of Jupiter that they did
under the bedstead. There is no combined result, and there is no
patentable combination.

But if an inventor takes a given mechanical e