00000262 |
Previous | 262 of 595 | Next |
|
small (250x250 max)
medium (500x500 max)
Large
Extra Large
large ( > 500x500)
Full Resolution
All (PDF)
|
THE MONSOONS. 237
and then strikes against the high mountains of the Himalaya, and other
chains, which border the plateaux of Central Asia on the south, but it does
not cross this barrier. By its clouds charged with rain, which are rent
by the escarpments ofthe inferior peaks, we see clearly that the sea-wind
does not pass the altitude of 4950 to 8250 feet, and that above it another
aerial stratum is moving in the heights. The movement which carries
.along this elevated stratum is the same as that of the monsoon from the
south-west; but we recognize by its long trains of cirri, from 16,500 to
25,500 feet high, that great returning current, or counter trade-wind, that
blows at the same elevation above the Atlantic in the neighborhood of
the Canaries.
When the sun, in its course over the ecliptic, returns toward the Tropic
of Capricorn, the centre of attraction is at the same time displaced in a
southerly direction. The monsoon of the south-west ceases to tend toward the great peninsulas of Asia, the regular wind from the north-east
recommences to blow, and the currents of attraction in the southern hemisphere turn back toward the islands of Sunda and Australia. Owing to
this regular alternation, which was a surprise to the ancient Greek navigator Hippalos, the mariners of the Indian Ocean may count beforehand
on a favorable wind which by turns will drive their ship before it for the
two passages, going and returning; and they have not to dread those prolonged calms which are the bane of sailing vessels in the equatorial zone
of the Atlantic and the South Sea. The circulatory system does not in
any place pass beyond the lower strata of the aerial ocean, and we may
easily perceive above the islands of Sunda and Australia, as well as4 over
the sides of the Himalayas, the constant progress of the clouds which are
brought by the regular trade-winds. A volcano of Java, observed by
Junghuhn, affords a remarkable example of this. From its summit, about
9900 feet high, a column of vapor escapes all the year round, which bends
gracefully in space, and directs itself toward the west, or north-west, in a
long wThitish cloud, and it is in precisely the opposite direction that the
monsoon blows during six months of the year, on the slopes as well as at
the foot ofthe mountains.
The monsoons of the East Indies are not the only winds which break
the uniformity of the trade-winds. In all those parts of the tropical zone
where tj^e shores of the continents are disposed parallel to the equator,
the winds alternate regularly, in consequence ofthe greater rarefaction of
the air, which occurs now on the earth, now on the sea, according to the
position of the sun. Thus, during the greater part ofthe year, the African coasts, which stretch from the Bight of Benin to Cape Palmas, attract
the monsoons ofthe Gulf of Guinea. These masses of air changing their
direction, turn back to blow in a north-easterly direction, and rush rapidly toward the great furnace of the Sahara, where the overheated atmosphere is usually more expanded than in any other country of the world.
Toward the month of January, when the Sahara itself has become colder
than the equatorial seas and the banks of the Congo, the trade-wind of
| Title | The ocean, atmosphere, and life |
| Creator | Reclus, Elisée |
| Publisher | Harper |
| Place of Publication | New York |
| Date | 1873 |
| Language | eng |
| Type | Books/Pamphlets |
| Title | 00000262 |
| Type | Books/Pamphlets |
| Transcript | THE MONSOONS. 237 and then strikes against the high mountains of the Himalaya, and other chains, which border the plateaux of Central Asia on the south, but it does not cross this barrier. By its clouds charged with rain, which are rent by the escarpments ofthe inferior peaks, we see clearly that the sea-wind does not pass the altitude of 4950 to 8250 feet, and that above it another aerial stratum is moving in the heights. The movement which carries .along this elevated stratum is the same as that of the monsoon from the south-west; but we recognize by its long trains of cirri, from 16,500 to 25,500 feet high, that great returning current, or counter trade-wind, that blows at the same elevation above the Atlantic in the neighborhood of the Canaries. When the sun, in its course over the ecliptic, returns toward the Tropic of Capricorn, the centre of attraction is at the same time displaced in a southerly direction. The monsoon of the south-west ceases to tend toward the great peninsulas of Asia, the regular wind from the north-east recommences to blow, and the currents of attraction in the southern hemisphere turn back toward the islands of Sunda and Australia. Owing to this regular alternation, which was a surprise to the ancient Greek navigator Hippalos, the mariners of the Indian Ocean may count beforehand on a favorable wind which by turns will drive their ship before it for the two passages, going and returning; and they have not to dread those prolonged calms which are the bane of sailing vessels in the equatorial zone of the Atlantic and the South Sea. The circulatory system does not in any place pass beyond the lower strata of the aerial ocean, and we may easily perceive above the islands of Sunda and Australia, as well as4 over the sides of the Himalayas, the constant progress of the clouds which are brought by the regular trade-winds. A volcano of Java, observed by Junghuhn, affords a remarkable example of this. From its summit, about 9900 feet high, a column of vapor escapes all the year round, which bends gracefully in space, and directs itself toward the west, or north-west, in a long wThitish cloud, and it is in precisely the opposite direction that the monsoon blows during six months of the year, on the slopes as well as at the foot ofthe mountains. The monsoons of the East Indies are not the only winds which break the uniformity of the trade-winds. In all those parts of the tropical zone where tj^e shores of the continents are disposed parallel to the equator, the winds alternate regularly, in consequence ofthe greater rarefaction of the air, which occurs now on the earth, now on the sea, according to the position of the sun. Thus, during the greater part ofthe year, the African coasts, which stretch from the Bight of Benin to Cape Palmas, attract the monsoons ofthe Gulf of Guinea. These masses of air changing their direction, turn back to blow in a north-easterly direction, and rush rapidly toward the great furnace of the Sahara, where the overheated atmosphere is usually more expanded than in any other country of the world. Toward the month of January, when the Sahara itself has become colder than the equatorial seas and the banks of the Congo, the trade-wind of |
|
|
|
|
|
|
| B |
|
| C |
|
| G |
|
| H |
|
| M |
|
| T |
|
| U |
|
| Y |
|
|
|
