ocean (oshan)

and a. [ earth, and covers almost three fourths of its surface with a mean depth-as nearly as can be estimated at the present time-of le than 12,500 feet. Physical geographers, following the lead of the Royal Geographical Society, generally divide the entire oceanic area into five distinct oceans, namely the Arctic, Antarctic, Atlantic, Pacific, and Indian; but these divisions are largely artificial, the lines by which they are indicated being in no small part parallels and meridians. The Arctic and Antarctic oceans, according to this scheme, extend from the north and south poles respectively to the arctic and antarctic circles. The Atlantic extends between the two polar circles, being limited on the east by the land-ma es of Europe and Africa and by the meridian extending from Cape Agulhas to the antarctic circle, and on the west by the American land-ma and the meridian of Cape Horn. The Pacific has as its land-limits on the east the American coast, and on the west the Asiatic land-ma , the Philippine Islands, New Guinea, and Australia; its imaginary limits are the meridians of Cape Horn and the South Cape of Tasmania prolonged to meet the antarctic circle. The Indian ocean extends south from the Asiatic mainland to the antarctic circle, its eastern and western imaginary limits having been already given in defining those of the Pacific and Atlantic. Thus, as will be noticed, there are no natural limits on the south of either the Atlantic, the Pacific, or the Indian ocean, since these all unite with the Antarctic ocean to form one continuous area of water. Hence it would be more philosophical to call the vast area of water occupying the chief part of the southern hemisphere the Southern ocean, as has been done by Herschel and Thomson, and to consider the Atlantic, Pacific, and Indian oceans as immense gulfs or prolongations toward the north of the still greater Southern ocean. The Pacific ocean was most generally designated by the older English navigators as the "South Sea," and this name is still current among the Germans. The Atlantic and Pacific are also generally divided into North and South Atlantic and North and South Pacific by the equatorial line. The smaller divisions of the ocean are, in the order of their respective magnitudes, seas, gulfs, bays, sounds, straits, coves, holes, and harbors (see each of these words). The mean depth of the ocean is probably not far from six times the mean elevation of the land above the ocean-level. The deepest soundings of the ocean, however, give figures a little inferior in amount to those indicating the elevation of the very highest mountain-summits. In several different parts of the ocean depths of over 26,000 feet have been sounded, but nowhere as yet has a depth as great as 29,000 feet (the height of Gaurisankar) been reached. (See deep - sea sounding - machine , under deep sea.) The oceanic currents are of great importance in their effect on climate. The principal surface current is the equatorial, due to the action of the trade-winds, by which the water is continually urged westward, but, being driven in its westerly course against the land-ma es, it is deflected by them, and forced to perform an immense gyration by which it returns into the general system far to the eastward. Owing to the shape of the land-ma es in the northern hemisphere, these modifications of the equatorial current are much more distinct and important than they are to the south of the equator. Two of the oceanic currents are especially interesting, the Gulf Stream of the Atlantic and the Kuroshiwo of the Pacific (see these terms). The surface temperature of the ocean varies greatly in the different latitudes and with the strength and direction of the surface currents, the Gulf Stream playing a most important part in ameliorating the climate of northwestern Europe by means of the heated surface water which it carries from the equatorial regions. Besides these surface currents, however, there is a general exchange of water always going on in the depths of the ocean between the warmer equatorial and the colder polar waters, brought about by the dif species having ocreate or booted tarsi, very long legs, the tibiæ extensively denuded, the tarsi longer than the mid- dle toe, the nails flat and blunt, the hallux minute, the wings long and pointed, the tail short and nearly square. The best-known species is O. oceanic a , or Wilson's petrel. There are several others, as O. line at a . The genus was founded by Count Keyserling and Dr. J. H. Blasius in 1840. Oceanitidæ (ō"se-a-nit'i-dē), n. pl. [NL., く Oceanites + -ida .] A family of oceanic birds lately separated by Forbes from the Pro cell a- riida. The family includes four genera of small petrels, Fregetta, Oceanites, Pela god rom a , and Garrodia . These are among the small petrels commonly called Mother Carey's chickens. oceanographer (ō" shē-a-nog'ra-fèr), n. [ One of the foremost duties of observing oceanographers . Encyc. Brit ., XXI. 613. oceanographic (ō-she-an-o-graf'ik), a . [ ocean- Destruction of Troy (E. E. T. S.), 1. 13254. ograph - y + -ic .] Relating to or connected with Than I sailet forth soundly on the Sea occian , With hom that I hade. The winds, with wonder whist, Smoothly the waters kist, Whispering new joys to the mild ocean , Who now hath quite forgot to rave, While birds of calm sit brooding on the charmed wave. Milton , Nativity, 1. 66. Old ocean's gray and melancholy waste. Bryant, Thanatopsis. 2. Something likened to the ocean; also, a great quantity: as, an ocean of trouble. oceanography. The word is sometimes used in place of oceanic when this latter would be more proper. The dif- ference between the two words is but slight, but it would seem that one is used when it is intended to convey a purely geographic idea, the other when the subject is looked at from a more general point of view: as, oceano- graphic phenomena; oceanic currents. oceanographical (ō-she-an-ō-graf'i-kal), a. [ oceanographic + -al.] Same as oceanographic . oceanographically (ō-she-an-ō-graf'i-kal-i), adv . As regards oceanography or the physical geography of the ocean. Amer. Jour. Sci ., 3d ser., XXX. 386. oceanography (ō"she-a-nog'ra-fi), n . [ ὠκεανός , the ocean, + -γραφία , γράφειν , write.] The science of the ocean: a special branch of geography. The term oceanography is little used in English except by writers translating from the German, who prefer oceanography to thala ography , while the best authorities writing in English at the present time use thala ography , which is a designation of that special branch of physical geography which relates to the ocean and its phenomena. The cable-laying companies have been the chief con- tributors to the science of deep-sea research, or oceanog- raphy . Nature , XXXVII. 147. Chemical oceanography - a branch of physical geogra- phy which has only lately come to be extensively culti- Encyc . Brit ., XXI. 611. oceanology (ō"she-a-nol'ō-ji), n. [ ὠκεανός , the ocean, + -λογία , λέγειν , speak: see -ology .] 1. The scientific study of the ocean. See ocean- ography.-2. A treatise on the ocean. ocellar (o-sel'är), a . [NL. ocellar is , lus , a little eye: see ocellus .] Of or pertaining to ocelli; ocellate. - Ocellar structure, the name given by Rosenbusch to a peculiar aggregation of mineral forms, chiefly microscopic in size, in which the individual components are arranged in rounded (ocellar) forms, or aggregated in branching, fern-like groups, which are some- times tangential and sometimes radial to the central ind i- vidual. This structure is most characteristically devel- oped in the leucitophyres. Also called centric structure by some English lithologists, by whom this term is used rather vaguely, sometimes as nearly the equivalent of mi- cropegmatitic. ophyric rocks are the micropegmatitic, the centric or ocel- lar structure, the pseudo spherulitic, the microgranitic, and the drusy or miarolitic structures. Judd, Quart. Jour. Geol. Soc. of London, XLV. 176. Ocellar triangle, a three-sided space, sharply defined in many insects, on which the ocelli are placed. ocellary (os'el-a-ri), a . [As ocellar +-y1.] Of or pertaining to ocelli; ocellar. Ocellary seg- ments or rings, in entom . , supposed primary segments of the preoral region, the ocelli in this case representing the jointed appendages of other segments. Dr. Packard distinguishes the first and second ocellary segments, which he regards as morphologically the most anterior of the body. He believes that the anterior ocellus represents appendages which have coalesced. See preoral. ocellate (os'el-at), a. [L. ocellatus, having little eyes, ocellus , a little eye: see ocellus .] 1. In zoöl . , same as ocellated ( c ). The remarkable genus Drusilla, a group of pale-coloured butterflies, more or le adorned with ocellate spots. A. R. Wallace , Nat. Select., p. 181. 2. In bot . , resembling an eye: said of a round spot of some color which has another spot of a different color within it. See cut in next depre ion having a central projection or part le deeply depre ed. ocellated (os'el-ā-ted), a . [ ocellate + -ed2.] Having or marked by ocelli. (a) Having ocelli, as an insect's eye. (b) Spotted. Besides the lion and tiger, almost all the other large cats... have ocellated or spotted skins. IMG:content-1613.jpg:[subsumed][subsumed][subsumed][merged small][graphic][subsumed][subsumed][merged small] 1, feather of peacock; 2, feather of argus-pheasant; 3, blenny; 4, owl- butterfly; 5, mariposa-lily. A very beautiful reddish ocellated one [butterfly]. Derham , Physico-Theology, viii. 6, note 6. Compound ocellated spot. See compound1 . Plural of ocellus . ocelli, n. ocelli cyst (ō-sel'i-sist), n. [L. ocellus , a little eye, + Gr. κύστις , bladder: see cyst .] One of the several kinds of marginal bodies of hydro- zoans, having a visual function; a so-called ocellus or pigment-spot in the margin of the disk. They are of ectodermal origin, developed in con- nection with the tentacles, and may even be provided with ocelli cystic (ō-sel-i-sis'tik), a . [ ocelli cyst + -ic.] Of, or having the character of, an ocelli- cyst. ocelli fer ous (os-e-life-rus), a . little eye, + ferre = E. bear1 .] resembling small eyes; ocellate. ocelli ger ous (os-e-lij'e-rus), a. little eye, + gerere , carry on.] ocelot (ō'se-lot), n. [ ocelotl .] The leop- ard-cat of America, Felis pardalis , one of sev- eral spotted American cats, of the family Felida . It is from 21 to nearly 3 feet long from the nose to the root of the tail, the latter about one foot in length. The color is grayish, mostly marked with large and small black- edged fawn-colored spots tending to run into oval or linear figures; the under parts are white or whitish, more or le marked with black. The back of the ear is usually black and white, and the tail is half-ringed with black. Indi- viduals vary interminably in the details of the markings, mostly preserving, however, the lengthened figure of the larger spots. The ocelot ranges from Texas into South America. See cut on following page. Oceanites (ō"sē-a-nītēz), n. [NL., Ὠκεα- νίτης, in pl. Ὠκεανίται , dwellers by the ocean: fem. Ὠκεανίτις, daughter of Ocean us; Ωκεα- νός , Ocean us: see ocean .] A genus of small pet- rels of the family Procellariida , or made type the wings of certain kinds [of butterflies). of Ocean i tid a. As defined by Coues, it is restricted to (c) Marked with or noting spots having a dark center and a lighter outer ring, as the spots on the tail of a peacock and on the wings of many butterflies. The conspicuous ocellated spots of the under surface of Science, IX. 435. ocher Ocelot ( Felis pardalis). cla of natural earths consisting of mixtures of the hydrated sesquioxids of iron with var i ous earthy materials, principally silica and alumina. These mixtures occur in many localities and have many shades of color, among which tints of red, reddish brown, yellow, and orange are most common. They form a series of valuable and important pigments, used extensively alike by house-painters and artists both in oil and in water-colors. The most usual and common type of ocher-color is a yellow turning neither to red on the one hand nor to brown on the other, but its tone is not as brilliant nor as pure as chrome-yellow. (For varieties, see below.) Ochers in general have much body and are very permanent. Most ochers on burning become redder and darker. Raw sienna and raw umber are varieties of ocher. 4076 a crowd, mob.] In med., a morbid condition induced by the crowding together of sick persons under one roof, or even of persons not suffering from disease. ochletic (ok-let'ik), a. [