evidence of design and system, which is not,
indeed, absolutely clear, but which is nevertheless abundantly
perceptible to minds that cannot hope in this life to see otherwise than
"through a glass, darkly."

The causes which modify the action of the winds are, as we have said,
various. Local causes produce local currents. A clear sky in one
region allows the sun's rays to pour upon, let us say, the ocean,
producing great heat; the result of which is evaporation. Aqueous
vapour is very light, therefore it rises; and in doing so the aqueous
particles carry the air up with them, and the wind necessarily rushes in
below to supply its place. The falling of heavy rain, in certain
conditions of the atmosphere, has the effect of raising wind.
Electricity has also, in all probability, something to do with the
creation of motion in the atmosphere. Now, as these are all local
causes, they produce local--or what, in regard to the whole atmosphere,
may be termed irregular--effects. And as these causes or agents are in
ceaseless operation at all times, so their disturbing influence is
endless; and hence the apparent irregularity in the winds.

But these causes are themselves, not less than their results, dependent
on other causes or laws, the workings of which are steady and unvarying;
and the little irregularities that appear to us in the form of
fluctuating and changing winds and calms may be compared to the varying
ripples and shifting eddies of a river, whose surface is affected by the
comparatively trifling influences of wind, rain, and drought, but whose
grand onward course is never for a single moment interrupted.

Among these disturbing influences, the Gulf Stream is a very important
one. It is constantly sending up large volumes of steam, which, rising
into the air, induce a flow of wind from both sides towards its centre.
And many of the storms that arise in other parts of the Atlantic make
for this stream, and follow its course.

So much has been ascertained by scientific investigation of the winds,
that we can now distinctly map out the great belts or currents which
pass right round the world. We can tell in which parallels winds with
easting, and in which those with westing, in them, will be most
frequently found; and by directing our course to such places, we can to
a certain extent count upon profiting by the winds that will be most
suitable. Before the facts of atmospheric circulation were known,
marine