ly have to trace
out in more involved cases, that in proportion to the heterogeneity of
the object or objects on which any force expends itself, is the
heterogeneity of the effects. A continent of complex structure, exposing
many strata irregularly distributed, raised to various levels, tilted up
at all angles, will, under the same denuding agencies, give origin to
innumerable and involved results: each district must be differently
modified; each river must carry down a different kind of detritus; each
deposit must be differently distributed by the entangled currents, tidal
and other, which wash the contorted shores; and this multiplication of
results must manifestly be greatest where the complexity of surface is
greatest.

Here we might show how the general truth, that every active force
produces more than one change, is again exemplified in the
highly-involved flow of the tides, in the ocean currents, in the winds,
in the distribution of rain, in the distribution of heat, and so forth.
But not to dwell upon these, let us, for the fuller elucidation of this
truth in relation to the inorganic world, consider what would be the
consequences of some extensive cosmical catastrophe--say the subsidence
of Central America. The immediate results of the disturbance would
themselves be sufficiently complex. Besides the numberless dislocations
of strata, the ejections of igneous matter, the propagation of
earthquake vibrations thousands of miles around, the loud explosions,
and the escape of gases; there would be the rush of the Atlantic and
Pacific Oceans to fill the vacant space, the subsequent recoil of
enormous waves, which would traverse both these oceans and produce
myriads of changes along their shores, the corresponding atmospheric
waves complicated by the currents surrounding each volcanic vent, and
the electrical discharges with which such disturbances are accompanied.
But these temporary effects would be insignificant compared with the
permanent ones. The currents of the Atlantic and Pacific would be
altered in their directions and amounts. The distribution of heat
achieved by those ocean currents would be different from what it is. The
arrangement of the isothermal lines, not only on neighbouring
continents, but even throughout Europe, would be changed. The tides
would flow differently from what they do now. There would be more or
less modification of the winds in their periods, strengths, directions,
qualities. Rain