comparatively
unimportant, but it is brought into prominence by the changes which
constitute a dynamic state. The static hypothesis requires that
capital should not increase or diminish in quantity, and that it
should not change its forms. The equipment of every mill and of every
ship is kept unimpaired but not enlarged or improved. There is a fixed
number of spindles in the cotton mill, of lathes in the machine shop,
of sewing machines in the shoe factory, etc., and this fact removes
the most striking difference which, in a dynamic society, actually
distinguishes land from other things.

Land, in the economic sense, does not increase in quantity, however
changeful and progressive a society may be. The chief distinguishing
mark of land--that of being fixed in amount--separates it from other
things only in a dynamic state and because of the action of the forces
which produce organic changes. These are subjects to be studied in the
dynamic division of economic theory.

_A Distinguishing Mark of Land which appears in a Static State of
Industry._--In a static state there remains this difference between a
piece of ground and a building, a tool, or any other instrument: the
ground is not artificially made and does not perish in the using;
while the building or the tool or other appliance is so made and does
so perish. It must in wearing itself out create in the indirect way
which we have described its own successor. The engine must, by a part
of its product, pay the men who will make another engine and so
perpetuate the series of engines. This makes it necessary for the
owner of the engine to save some of its gross rent to pay for
depreciation and renewal, while he can safely use the whole rent of
land.

_This Mark of Distinction not Applicable when Land is contrasted with
a Permanent Stock of Capital Goods._--If we look, not at one
particular instrument, but at an entire series of them,--if we take
into view, not only the engine which is now driving the mill, but also
the one that will succeed it, and again the one which will succeed
that second engine, and so on forever,--this difference between land
and the artificial instrumentality vanishes. _The series of engines,
like land itself, yields only a net rent._ The remainder of its gross
product is not a true rent at all, since any one of the engines
creating it has to consume it on itself and cannot give it to the
owner as an income. This remainder pays certain men for