. A directory for the North Atlantic Ocean, comprising instructions general and particular for its navigation. Pilot guides. THE ANTI-TEADES OR PASSAGE WINDS. 185 (119). Anti-Cyclones.—In (34) an Anti-Cyclonic system is described as an area of relatively high barometric pressure, around which, in the Northern Hemisphere, the wind blows with watch-hands, , contrary to what it does in a Cyclone, but drawing slightly otit from the centre, as shown in the adjoining diagram. It is conjectured that within such an area the air is descending from higher regions, and spreads out over the lower baro
. A directory for the North Atlantic Ocean, comprising instructions general and particular for its navigation. Pilot guides. THE ANTI-TEADES OR PASSAGE WINDS. 185 (119). Anti-Cyclones.—In (34) an Anti-Cyclonic system is described as an area of relatively high barometric pressure, around which, in the Northern Hemisphere, the wind blows with watch-hands, , contrary to what it does in a Cyclone, but drawing slightly otit from the centre, as shown in the adjoining diagram. It is conjectured that within such an area the air is descending from higher regions, and spreads out over the lower barometric areas surrounding it. Mr, Ley remarks :—" An Anti-Cyclone represents the position of a downward movement of the air, which has lost the greater part of its water vapour in previous Cyclonic circulations. In the district, therefore, near the central calm of an Anti- Cyclone, the currents take up instead of precipitating vapour; this explains jvhy it has no principle of progressive development (or forward movement). The Anti-Cyclone presents a great contrast to the Cyclone in this respect, that instead of shifting their geographical position rapidly, they are ex- ceedingly sluggish in their movements; and, indeed, frequently remain stationary for a very considerable period. (120.) " Here the reader is warned against another possible misappre- hension. The terms ' Cyclone ' and ' Anti-Cyclone' do not refer to the actual level of the barometer within the areas to which they are applied, but to its level relatively to the level in surrounding districts. The observer may find the mercury in his barometer above its mean height (23), and yet may possibly be situated at the centre of a Cyclonic system at the time, because the mercury may be still higher at all stations at a certain distance from his own. Contrariwise he may find the mercury in his barometer below the mean, and yet may be at the centre of an Anti-Cyclone, because the barometers on all sides of his st
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