What was the extraordinary rate in the case of the ship Northampton quoted by Horsburgh? 139 miles in twenty-four hours, or five miles and a-half per hour, a velocity which finds a parallel only in the maximum of the Gulf Stream. What currents prevail in the Bay of Bengal? They entirely depend on the monsoons. What is the current through the Straits of Malacca ? Between the Nicobar Isles, and Junk-Ceylon, the current sets strong to the north-west and north, during the north-east monsoon. What is the Cape Counter Current? An easterly current from the south Atlantic, carrying the waters repulsed by the bank of Agulhas back into the Indian Ocean in high latitudes. What is its velocity? Its mean velocity off the Cape is about fifty miles per day. How far has this current been observed to the eastward? According to Major Rennell, as far as longitude 65° 15' E. What current has been observed off the south-west coast of Australia? According to Flinders, the current divides near Cape Leeuwin into two streams, one of which flows north and the other east, along the coast of Australia. What is the maximum temperature of the Indian Ocean? 87° 40', in lat. 9° 55' N., and long. 59° 52′ E. What is the maximum temperature of the Pacific? 88° 52', in lat. 0° 0; long. 135°, E. What is the maximum temperature of the Atlantic? 88° 52', in lat. 28° N.; long 88° W. What is the mean temperature of the atmosphere at the equator of heat? 82 4'. Making a difference in favour of the heat of the ocean of 6° 11'. CHAPTER XII. WINDS &c., OF THE INDIAN OCEAN. What is the prevailing wind of the Indian Ocean? Where does this wind blow most powerfully? In what part of the year does the south-east trade wind blow with the greatest steadiness? From April to October. What is its character after October? Its force and regularity gradually decreases, as the solar heat increases, until it ceases in the vicinity of the equator; its northern limit in the hot season being 10° or 12° S., at which time the southern limit extends to 29° or even 30° S. What winds prevail to the southward of the zone of the south-east trade wind? The north-west winds, which prevail nearly in the same latitudes in the Atlantic and Pacific Oceans. What are the monsoons? Winds which blow six months in the year in one direction, and, during the other six months, in an opposite one. When does the change occur? About the 15th April and 15th October. They prevail over a tract extending from latitude 7° or 8° south of the equator, to the countries of Asia on the north; and from the channel of Mozambique and the Red Sea on the west, to the shores of Australia and the China Sea on the east. How do the monsoons blow on the north side of the equator? The north-east monsoon prevails with little variation, from October to April; while from April to October the south-west monsoon prevails in the same region, How do the monsoons blow on the south side of the equator? The north-west monsoon prevails in the south at the same time as the north-east blows on the north, and the south-west monsoon of the north becomes the south-east monsoon of the south of the line. What variation is observed in these winds during the hot season? When the south-east trade wind recedes to the southward, the space between the line and 18° or 12° south, is occupied by the north-west monsoon, which then attains its southernmost limit. Is any part of the coast of Australia within the limit of the east and west monsoon? Yes, that part from Cape York to Cape Van Diemen, and extending as far to the south as the parallel of 12° south latitude, may be said to be within the limit, at a short distance from the coast. What has been observed near the land there? That the easterly monsoon sets in between the 1st and middle of April, and the westerly monsoon in October, and sometimes not until November. When did the westerly monsoon set in at Port Essington in 1833 ? In the first week of November. What has been observed of monsoons in the Pacific? That the westerly monsoon extends to the eastward as far as the island of Otaheite. Where do hurricanes prevail in the Indian Ocean? They are confined generally, to the region extending from latitude 9 or 10° to 30° or 35° south, and from eastward of Madagascar on the west, to the south side of the Island of Timor on the east. What has been observed of the most authentic storms occurring within these limits? That they travel with remarkable uniformity from the north-east, in a direction south-west and south towards the east again. What are Tyfoons? The hurricanes which prevail on the coasts of China.. Describe the region of the Tyfoons ? Tyfoons extend from the coasts of China, to the east of the Island of Luçon, seldom further north than the islands of Japan, nor further to the south than latitude 14° north, and blowing with the greatest violence in the vicinity of the land. CHAPTER XIII. ROUTE OF VESSELS THROUGH THE INDIAN OCEAN. What is the most direct route for vessels bound from Europe to India, after doubling the Cape of Good Hope? The most direct, called the Inner Passage, is through the Mozambique Channel, between Madagascar and the coast of Africa. At what season is this route followed? When the voyager leaves the Cape of Good Hope at such a season of the year, as may lead him to calculate on arriving at the Coast of India, during the prevalence of the south-west monsoon. When is this passage safest? During the dry season, or from April to September. In how many days did Krusenstern perform this voyage? In forty days from the Cape to Madras Roads. Why do some prefer the passage to the eastward of Madagascar? Because of the dangers of the channel of Mozambique, which are now better known, however; and the eastern passage being the longest, it is not used so much as formerly. What is the Boscawen Passage? This track is to the northward of the Mauritius and west of Malha Bank. What vessels follow this track? Ships bound for Bombay, or the Malabar coast, when late in the season, and unable to arrive there before the setting in of the north-east monsoon. When is this and the middle passage considered most advantageous? For ships which do not pass the Cape before the 1st September. What is the direction of the middle passage? The middle passage is to the eastward of the former, having the Madagascar Archipelago to the west, and the Chagos Isles to the east. What are the outer passages ? Those to the eastward of the Chagos Isles. When is the most easterly of these taken? When ships are expected to arrive at Madras, or in the Bay of Bengal, during the full force of the north east monsoon. What is the course then? From the Cape, the course is so far to the eastward, that the south-east trade wind is sought to be met with first in longitude 80° or 85° east, it is then necessary to steer nearly due north, until the ship nears Cape Acheen, the northern point of Sumatra. Do such vessels make Cape Acheen? No, they avoid coming in sight of it, because of the light north-west and westerly winds prevailing there, and besides, a strong current which sets into the Strait of Malacca. What course is taken by vessels bound for the Coast of Coromandel? They do not approach so near to Cape Acheen; it is sufficient to make the longitude of 90° east, whence the course may be taken to Madras. What renders the sailing from one part of India to another difficult? The prevalence of the monsoons; a voyage from Calcutta to Madras, or from Madras to Bombay, may be made in a short time during the north-east, but not so during the south-west monsoon. Are the routes of sailing vessels very circuitous, as compared with the tracks of steamers along the coasts? Yes. What is proved by that fact? |