t is broken up by the variable winds which it encounters.

A very interesting and, from the point of view of the navigator,
important peculiarity of these whirls is that at their centre there is
a calm, similar in origin and nature to the calm under the equator
between the trade-wind belts. Both these areas are in the field where
the air is ascending, and therefore at the surface of the earth does
not affect the sails of ships, though if men ever come to use flying
machines and sail through the tropics at a good height above the sea
it will be sensible enough. The difference between the doldrum of the
equator and that of the hurricane, besides their relative areas, is
that one is a belt and the other a disk. If the seafarer happens to
sail on a path which leads him through the hurricane centre, he will
first discern, as from the untroubled air and sea he approaches the
periphery of the storm, the horizon toward the disturbance beset by
troubled clouds, all moving in one direction. Entering beneath this
pall, he finds a steadily increasing wind, which in twenty miles of
sailing may, and in a hundred miles surely will, compel him to take in
all but his storm sails, and is likely to bring his ship into grave
peril. The most furious winds the mariner knows are those which he
encounters as he approaches the still centre. These trials are made
the more appalling by the fact that in the furious part of the whirl
the rain, condensing from the ascending air, falls in torrents, and
the electricity generated in the condensation gives rise to vivid
lightning. If the storm-beset ship can maintain her way, in a score or
two of miles of journey toward the centre, generally very quickly, it
passes into the calm disk, where the winds, blowing upward, cease to
be felt. In this area the ship is not out of danger, for the waves,
rolling in from the disturbed areas on either side, make a torment of
cross seas, where it is hard to control the movements of a sailing
vessel because the impulse of the winds is lost. Passing through this
disk of calm, the ship re-encounters in reverse order the furious
portion of the whirl, afterward the lessening winds, until it escapes
again into the airs which are not involved in the great torment.

In the old days, before Dove's studies of storms had shown the laws of
hurricane movement, unhappy shipmasters were likely to be caught and
retained in hurricanes, and to battle with them for weeks until their
ve