My understanding was limited to knowing zero degrees latitude began at the equator and increased to ninety degrees at the poles.
Though the islands are under the equator, the climate is not intensely hot, as it is tempered by cold currents from the Antarctic sea, which, having followed the coast of Peru as far as Cape; Blanco, bear off to the N.W.
The Atlantic Ocean consists of two characteristic divisions, the geographical equator forming a fairly satisfactory line of division into North and South Atlantic. The North Atlantic, by far the best-known of the main divisions of the hydrosphere, is remarkable for the immense length of its coast-line and for the large number of enclosed seas connected with it, including on the western side the Caribbean Sea and Gulf of Mexico, the Gulf of St Lawrence and Hudson Bay, and on the eastern side the Mediterranean and Black Sea, the North Sea and the Baltic. The North Atlantic is connected with the Arctic Basin by four main channels: (1) Hudson Strait, about 60 m.
The heat equator, or line of maximum mean surface temperature, starts from the African coast in about 5° N.
The arc measured was 3° 7' 3" in length; and the work consisted of two measured bases connected by a series of triangles, one north and the other south of the equator, on the meridian of Quito.
This takes account of - (I) the ArcticAlpine zone, including all the vegetation of the region bordering on perpetual snow; (2) the Boreal zone, including the temperate lands of North America, Europe and Asia, all of which are substantially alike in botanical character; (3) the Tropical zone, divided sharply into (a) the tropical zone of the New World, and (b) the tropical zone of the Old World, the forms of which differ in a significant degree; (4) the Austral zone, comprising all continental land south of the equator, and sharply divided into three regions the floras of which are strikingly distinct - (a) South American, (b) South African and (c) Australian; (5) the Oceanic, comprising all oceanic islands, the flora of which consists exclusively of forms whose seeds could be drifted undestroyed by ocean currents or carried by birds.
- Excepting towards the north, where, in Mexico, it meets, and inosculates with the Nearctic subregion, the boundaries of the Neotropical region are simple enough to trace, comprehending as it does the whole of South America and all Central America; besides including the Falkland islands to the south-east and the Galapagos under the equator to the west, as well as the Antilles or West India islands up to the Florida channel.
Hence the study of the mountain ranges of a continent is, for a proper apprehension of its physical conditions and characteristics, as essential as the examination of its extent and position in relation to the equator and poles, and the configuration of its coasts.
Among the islands of the Malay Archipelago the force of the monsoons is much interrupted, and the position of this region on the equator otherwise modifies the directions of the prevailing winds.
In the islands under the equator the heaviest fall is between October and February.
In its simplest form, consisting of a ring fixed in the plane of the equator, the armilla is one of the most ancient of astronomical instruments.
Since the difference between the acceleration of gravity at the pole and at the equator is about 2%, the correction for latitude will be quite sensible in an instrument which might be used at various times in high and low latitudes.
Of the parallels of latitude, the equator only is a great circle.
The scale of that map, as determined by the equator or centre meridian, we will suppose to be i: 125,000,000, while the encircling meridian indicates a scale of i: 80,000,000; and a " mean " scale, equal to the square root of the proportion which the area of the map bears to the actual area of a hemisphere, is r: 112,000,000.
Following Hipparchus he divided the equator into 360 drawing his prime meridian through the Fortunate Islands (Canaries).
On the original only equator, ecliptics, tropics, polar circles and one meridian 80° to the west of Lisbon are laid down.
This main scheme is complicated in various ways: (r) by the rotation of the earth, which continually deflects currents of water or air to the right in the northern or to the left in the southern hemisphere; (2) by the conformation of the land masses (as in the case of the equatorial stream which is banked up in the Gulf of Mexico and flows out through the Straits of Florida); (3) by the varying depth of the ocean, for currents tend to flow more readily through deep than in shallow waters (as in the case of the main Atlantic drift, which flows most strongly through the deep channel between Shetland and the Faroe Is.); and (4) by the driving force of the winds acting on the surface of the sea (thus the drift of water from the equator is not N.E., as one might expect, but from E.
The bottom water is relatively rich in these substances as well as in decaying organic matter, and would become progressively richer but for the slow drift towards the equator and the welling-up of bottom water to the surface in these latitudes.
The angle which the magnetic axis makes with the plane of the horizon is called the inclination or Along an irregular line encircling the earth in the neighbourhood of the geographical equator the needle takes up a horizontal position, and the dip is zero.
Laplace treated the subject from the point of view of the gradual aggregation and cooling of a mass of matter, and demonstrated that the form which such a mass would ultimately assume must be an ellipsoid of revolution whose equator was determined by the primitive plane of maximum areas.
In area, is on the east coast of the island, almost directly on the equator, and has a very uniform and' high temperature and a very high rainfall.
Crossing the equator in 13 6 ° W.
Schott's investigations show that the annual range of surface temperature in the open ocean is greatest in 40° N., with 18.4° F., and in 30 S., with 9.2° F.; on the contrary, near the equator it is less, only 4° F.
The zones of surface temperature are arranged roughly parallel to the equator, especially in the southern hemisphere.
Is only from 3 2.2° to 32.7° F., and the same low temperature continues throughout the Brazil Basin to the equator; but in the North American Basin from the West Indies to the Telegraph Plateau no satisfactory bottom temperature lower than 35.6° F.
The trade-wind regions correspond pretty closely with westward-flowing currents, while in the equatorial calm belts there are eastward-running countercurrents, these lying north of the equator in the Atlantic and Pacific, but south of the equator in the Indian Ocean.