Equator

“ The regions round the equator are full of splendid scenes. Even colder realms, in their frequent changes, have great variety—some silvery in whiteness, when the moist rain falls frozen to the earth in flakes ”

“ From this equatorial zone, the heart of the globe, come forth two rivers of tepid water that heat the coasts of the north. They are the two currents that issue from the Gulf of Mexico and the Java Sea. Their enormous liquid masses, fleeing ceaselessly from the equator, govern a vast assemblage of water from the poles that comes to occupy their space, and these chilled and fresher currents are constantly precipitating themselves on the electric hearth of the equator that warms and salts them anew, renewing with its systole and diastole the life of the world. ”

“ As the tide leaves its drift in horizontal lines, though rising higher on the shores where the tide rises highest, so have the living waters left their living drift on our mountain-summits, in a line gently rising from the arctic lowlands to a great height under the equator. ”

“ The ocean of air is a vast maelstrom, boiling up always under the influence of the sun's heat at the equator, and flowing as an upper current towards either pole, while an undercurrent from the poles, which becomes the trade-winds, flows towards the equator to supply its place. ”

“ Becoming water and losing its velocity, it would approach the tropics by a similar, but reversed spiral, turning towards the west. Owing to the principle here alluded to, all currents from the equator to the poles should have an eastward tendency, and all from the poles towards the equator a westward. Let us now suppose the solid nucleus of this hypothetical globe to assume the exact form and shape of the bottom of our seas, and in all respects, as to figure and size, to represent the shoals and islands of the sea, as well as the coast lines and continents of the earth. ”

“ In the study also of the climates of the earth, and their effects upon life, we find the ocean bears a most important part. As the circulation of the atmosphere mingles the heated air from the equator with that of the frozen regions of the poles, so the currents of the ocean circulate about the earth, blending the contrasts of climate, and making a harmonious whole of all the different portions. ”

“ Because, as the north and the south winds move towards the equator, they drive before them volumes of atmosphere, which, meeting in opposite directions, resist and counterpoise each other, and abide in a state of stillness between the north and south-easterly winds, one on the north and the other on the south of the equator. ”

“ In order to study the special features of tropical nature, on the other hand, it will be advisable to confine our attention mainly to that portion of the globe which extends for about twelve degrees on each side of the equator, in which all the chief tropical phenomena dependent on astronomical causes are most fully manifested, and which we may distinguish as the “equatorial zone.” ”

“ The gentleman again observes, "That the air under the equator, and between the tropics, being constantly heated and rarefied by the sun, rises; its place is supplied by air from northern and southern latitudes, which, coming from parts where the air and earth had less motion, and not suddenly acquiring the quicker motion of the equatorial earth, appears an east wind blowing westward; the earth moving from west to east, and slipping under the air." ”

“ When the rarefied equatorial air has travelled some thirty or forty degrees of latitude along the upper regions of the atmosphere towards the poles it becomes cooled, and is ready to descend again, between the latitudes of 30° and 60°, to supply the place of the lower air, drawn off towards the equator by the Trade-winds. ”

“ Likewise, when the eastern flow towards the poles, strikes against the western sides of a continent, it is deflected towards the equator. Hence the northern parts of both the Atlantic and Pacific, have a tendency to a vortical motion, their tropical parts moving westward, and then turning northward on the eastern sides of the continents and joining the eastern flow, and south again towards the equator on the western sides of the continents. ”

“ Thus, on different circles of longitude, places which, having the same latitude, should have the same mean annual temperature, may, and do, differ in this respect several degrees, from the dissimilitude of the ground, and from the different relations they bear to the masses of land and surfaces of sea. Under the equator the land is generally hotter than the sea ”

“ They have followed the northward set of the heated waters of the equator and have shown how they form those wonderful rivers of warm water that flow, without walls, through the colder waters of the sea, till they strike the western shores of Europe and America, and how they render habitable the almost Arctic countries of Great Britain and Alaska. ”

“ If, when you and the sun are between the equinoctial and the antarctic pole, the shadow falls towards the north, you will add the altitude you have taken to the sun's declination that day, and act according to the second rule. 5. When you have an altitude of 90 deg., you will be so many degrees distant from the equator as there are degrees of the sun's declination, and if the sun has no declination you will be under the equator. ”

“ Now, if it had been so, since the earth is flattened more than five leagues at the pole, the seas, carried to the equator by centrifugal force, would have covered mountains twice as high as the Himalayas; all the countries near the polar circle, Sweden, Norway, Russia, Siberia, Greenland, and New Britain, would have been buried in five leagues of water, while the regions at the equator, having become the pole, would have formed plateaus fifteen leagues high! ”

“ We know that cold ocean-rivers pour from north-polar regions to the south, both in the Atlantic and in the Pacific. A general creeping under-flow of icy waters towards the equator evidently balances the general surface drift of warm waters towards the poles. Since cold water is heavier than warm, it would naturally find its way to lower depths, leaving the warm light liquid to float on the top. ”

“ When the moon has no declination, the highest tides should occur along the equator, and the heights should diminish from thence toward the north and south; but the two daily tides at any place should have the same height. ”

“ Polar waters always flow towards the equator, still partaking, however, of the westerly direction unless deflected by local causes; and, being cold, flow beneath the warmer currents, which have been expanded by equatorial heat, until, being warmed, they gradually rise and mingle with the equatorial currents, which, in addition to their westerly motion, also flow towards the Poles, till, becoming cooled, they sink and merge with the Polar waters, thus maintaining a continued circulation. ”

“ The motions of the Gulf Stream (§ 53) , beating time for the ocean and telling the seasons for the whales, also suggest the idea of a pulse in the sea, which may assist us in explaining some of its phenomena. At one beat there is a rush of warm water from the equator toward the poles, at the next beat a flow from the poles toward the equator. ”

“ The trade winds prevail about thirty degrees on each side of the equator. This part of the ocean may be called the Elysian Fields of Neptune’s empire; and the torrid zone, notwithstanding Ovid’s remark, “non est habitabilis æstu,” is rendered healthy and pleasant by these gently-blowing breezes. The ship glides smoothly on, and you soon find yourself within the northern tropic. ”

“ Here being cooled, and agitated, and mixed up with waters that are less salt, these overheated and over-salted waters from the tropics may be replenished and restored to their rounds in the wonderful system of oceanic circulation.
270. There are also about the equator in this ocean some curious currents which I do not understand, and as to which observations are not sufficient yet to afford the proper explanation or description. There are many of them, some of which, at times,
PAGE 140 THE PHYSICAL GEOGRAPHY OF THE SEA.
run with great force. ”

“ If the water became more dense, or if the world were to revolve faster, the oceans would rush to the equator, burying the tallest mountains and leaving polar regions bare. If the water should become lighter in an infinitesimal degree, or the world rotate more slowly, the poles would be submerged and the equator become an arid waste. ”

“ If you are to the north of the equator, and the sun is in the southern signs you will look what is its declination, you will add these degrees of declination to those of the altitude observed, and as many degrees as are wanting from 90 deg., so many will you be distant from the equinoctial. ”

“ If such a body of water be situated upon the earth's equator, high water will occur at its east end three lunar hours before the upper or lower culmination of the moon and low water, three hours after such times. When it is high water at the east end, it will be low water at the west end, and vice versâ. The amount of the rise and fall (i. e., the range of tide) at either end will be one thirteen-millionth part of the length of the body of water. ”

“ These mountains are near the equator, and the relation which they sustain to the surrounding seas, and to currents of wind which blow in that quarter of the world, is such, that they bring down from the atmosphere, especially in certain seasons of the year, vast and continual torrents of rain. ”

“ Equator or equinoctial line: An imaginary line passing round the earth, from east to west and directly under the sun, which always shines nearly perpendicularly down upon all countries situated near the equator. ”

“ On the oppressive, clouded days, such as are peculiar to this part of the watery Equator, the dark, vitrified masses, many of which raise themselves among white whirlpools and breakers in detached and perilous places off the shore, present a most Plutonian sight. ”