_from his left to his right hand_. Now the connexion of the barometer
with this phase of the storm is _falling with the wind from left to
right, the observer facing the centre while the first half is
transiting_.[1] During the latter half these conditions are reversed,
the observer still keeping his position, his face directed to the S.W.,
the barometer _rises_ with a N.W. wind, which rushes past him _from his
right to his left hand_ with a decreasing force. We have therefore _a
rising barometer with the wind from right to left during the latter half
of the storm, the observer having his back to the centre_.
The above _general_ enunciations of the barometric and anemonal
phaenomena of a rotating storm hold good with regard to the _northern_
hemisphere, whatever may be the direction in which the hurricanes
advance. This may be placed in a clearer light, as well as the remaining
classes of phaenomena shown, by consulting the following tables,
constructed for the basin of the Northern Atlantic, and comparing them
with fig. 1. In this basin, with lower latitudes than 25 deg., the usual
paths of the hurricanes are towards the north-west, in higher latitudes
than 30 deg. towards the north-east. The tables exhibit the veering of the
wind with the movements of the barometer, according as the ship is
situated in the right or left hand semicircle of the hurricane. It must
here be understood that the right and left hand semicircles are
determined by the observer so placing himself that his face is directed
towards the quarter to which the hurricane is advancing.
LOWER LATITUDES.
NORTHERN HEMISPHERE.
Axis line, wind N.E., barometer falling, first half of storm.
Axis line, wind S.W., barometer rising, last half of storm.
RIGHT-HAND SEMICIRCLE.
Wind E.N.E., E., E.S.E., S.E., barometer falling, storm increasing.
Wind S.S.W., S., S.S.E., S.E., barometer rising, storm passing off.
LEFT-HAND SEMICIRCLE.
Wind N.N.E., N., N.N.W., N.W., barometer falling, storm increasing.
Wind W.S.W., W., W.N.W., N.W., barometer rising, storm passing off.
HIGHER LATITUDES.
NORTHERN HEMISPHERE.[2]
Axis line, wind S.E., barometer falling, first half of storm.
Axis line, wind N.W., barometer rising, last half of storm.
RIGHT-HAND SEMICIRCLE.
Wind S.S.E., S., S.S.W., S.W., barometer falling, storm increasing.
Wind W.N.W., W., W.S.W., S.W., barometer rising, storm passing off.
LEFT-HAND SEMICIRCLE.
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