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and level, and that a wave ten feet high Seas, "flows into the Pacific, like another flows through the Straits of Babelmandeb Gulf Stream, between the Philippines and up the channel at the rate of twenty miles the shores of Asia,” towards the Aleutian a day, for fifty days, losing half-an-inch Islands, tempering climates, and losing daily by evaporation. In this case it is itself on its way to the north-west coast of obvious that, at the end of the fiftieth day, America. the wave will be twenty-five inches lower After treating of the currents in the than it was on the day it began to flow. Pacific, of Humboldt's current on the The surface of the sea consequently be coast of Peru, of under-currents and the comes an inclined plane by evaporation. currents in the Atlantic, Lieutenant MauThe salt water, therefore, grows salter and ry proceeds to discuss the very interestheavier; and as the lighter water at the ing subject of “The open sea in the ArcStraits can not balance the colder, salter, tic Ocean.” Dr. Scoresby informs us and heavier water at the Isthmus, the lat- that whales have been caught near Behter must run out as an under-current, ring's Straits with harpoons in them beotherwise it would “abstract all the longing to ships known to cruise in Bafwater from the ocean to make the Red fin's Bay; and as it has been ascertained Sea brine,” and ultimately a mass of solid that these whales could not have passed salt.
round Cape Horn or the Cape of Good It has been long ago ascertained, that Hope, it follows that they must have trawhile there is a surface current from the veled in open water through the Arctic Atlantic always running into the Mediter- Sea. As an additional argument for an ranean, there is an outward under-current open sea near the Pole, our author menrunning into the Atlantic, and charged tions the existence of a warm under-curwith the additional salt produced by rent from the Atlantic into the Arctic evaporation from the inland sea. This Ocean through Davis's Straits, and he opinion of our author has been contro- adds the opinions of Lieutenant De Haven, verted by Admiral Smyth and Sir Charles Captain Penny, and Dr. Kane,* who Lyell, from the fact that water taken fifty found an open sea in very high latitudes. miles within the Straits, from a depth of Important as these arguments are, the 4020 feet, was found by Dr. Wollaston to existence of an open sea at the North Pole be four times salter than common sea itself may be inferred from the existence water, combined with the fact that the of two poles of maximum cold surrounded greatest depth of water at the Straits is by isothermal lines indicating increasing 1320 feet. Hence they conclude that temperatures as we approach the Pole water, lying at depths greater than 1320 along the cold meridians which pass feet, can never flow out into the Atlantic through the poles of cold, and the pole of over the submarine barrier at the Straits. revolution. Lieut. Maury is at much pains to refute The influence of the saltness of the sea this apparently formidable objection to his on the equilibrium of its waters is the theory, but he required only to refer to subject of Lieutenant Maury's ninth chapthe beautiful experiments of Venturi on the ter. We have already seen that, owing lateral communication of motion in fluids to evaporation from its surface, which infrom which it is proved that a current creases the saltness of the sea in certain of pure water passing over a deep pool of places, and to the introduction of large ink, or any other fluid colored on purpose, rivers of fresh water, and heavy falls of would soon empty the pool, and replace rain, which diminishes its saltness in the ink or colored fluid with the pure others, it must have various degrees of water of the current. Hence it is mani- saltness in different localities.
The curfest that the brine or very salt water rents, however, which we have described which may occupy the depths or cavities as in the waters which have different deof the Mediterranean Sea must be carried grees of saltness, produce sea water of a out into the Atlantic. Owing to the high uniform degree of saltness; so that "the temperature of the Indian Ocean, large constituents of sea water are, generally currents of warm water have their origin speaking, as constant in their proportions there. One of these is the Mozambique as are the components of the atmosphere." or Lagullas current. Another, escaping In order to explain why the sea is salt and through the Straits of Malacca, and joined by others from the Java and China
* See this Journal, vol. xxvi., pp. 228, 229, 236.
not fresh, Lieutenant Maury suggests that climates in parts of the earth far removed one of its purposes was to impart to its from the spots where they dwell. waters the forces and powers necessary to
Without entering into the question, make their circulation as complete,” and whence does the sea derive its saltness “as perfect as is that of the atmosphere whether, according to Darwin, from the or blood.” In support of his opinion, that washings of rains and rivers, or, as ieuthe sea has a system of circulation for its tenant Maury believes, from the Alwaters, our author refers to the coral mighty's fiat on the morning of the creaislands, reefs, beds, and atolls of the Paci- tion-it is interesting to notice the quanfic, built up with materials quarried, as tity of solid matter, in the form of salts, he expresses it, by a certain kind of insect which the sea holds in solution. Taking from sea water, which contains 3} per cent the average depth of the ocean at two of solid matter supplied by rivers, in the miles, and its average saline strength at form of common salt, sulphate and car- three and a half per cent, its salt would bonate of lime, magnesia, soda, potash, cover, to the thickness of one mile, an area and iron. If fresh supplies of these mate- of seven millions of square miles, all of rials were not obtained by currents, the which passes into the interstices of sea little creatures that build the coral rocks water without increasing its bulk. would perish for want of food before their In a short chapter on “The Equatorial work was finished.
Cloud Ring,” illustrated by his “ Diagram Did the sea consist of fresh water, a of the Winds,” we have the terraqueous feeble system of circulation would be globe divided into nine portions. produced by heat and evaporation alone, 1. The Equatorial Cloud Ring, or the excluding the influence of the winds. Belt of Equatorial Calms and Rains, or Surface currents of warm and light water the Equatorial “Doldrums” of the sailor would pass from the Equator to the Pole, -a word which we hope will escape
from and another set of under-currents, of future treatises on the sea. cooler, dense, and heavy water, would 2. The North-East Trade-Winds. pass from the Poles towards the Equator, 3. The Calm Belt of Cancer the But if the sea consisted of salt water, " Horse Latitudes ” of the sailor. which contracts as its temperature is low- 4. The prevailing winds from the Equaered till it reaches 28°, a new force is tor towards the North Pole. called into play. Evaporation in the trade- 5. The North Polar Calms. wind region lowers the sea level, and in- 6. The South-East Trade-Winds. creases the saltness of the sea. The water 7. The Calm Belt of Capricorn. thus heavier sinks, while the lighter water 8. The prevailing winds from the Equarises, producing a vertical circulation. tor towards the South Pole. The raised vapor, carried by the currents 9. The South Polar Calms. of air to colder regions, gives to the ocean The Equatorial Calm Belt is not only more fresh water as rain, or snow, than it the region of calms and baffling winds, returns to the atmosphere as vapor. The but also of rains and clouds; and under sea level is thus raised, and being depressed its dense, close, and sultry atmosphere, in the evaporating regions, a system of the Australian emigrants find it a “ frightsurface currents, moved by gravity alone, ful graveyard” for children and delicate passes from the Poles towards
the passengers. Under this cloud ring, which Equator.
encircles the earth, the thermometer and If the sea had not been salt from “the barometer stand lower than in the clear beginning,” there would have been none weather on either side of it. of the sea-shells that cover the top of the allels over which it hangs, it promotes the Andes, or those infusorial deposits which precipitation of rain at certain periods; astonish us by their magnitude and extent, and " by traveling with the calm belt of and none of the coral islands which adorn the Equator to the north or south, it the Pacific. When the rains dissolve the shifts the surface from which the heating salts of the earth, and the rivers carry rays of the sun are to be excluded, and them to the sea, the marine insects elabo- gives a tone to the atmospherical circularate them into pearls, shells, and corals; tion of the world, and a vigor to its vegeand while they are preserving the purity tation.” When it has thus left the Equaof the sea, they assist in the regulation of tor, the rays of a vertical “ torrid sun”
In the par
scorch the earth. Plants wither. Ani- tion or depression of the Dead Sea basin, mals die. The mitigating cloud ring re- and that the upheaval of mountain ranges turns, and the burning rays of the sun are and continents across the course of the no longer received on the surface of the winds has, by means of the winds proearth, but upon the upper surface of the duced upon inland lakes, the effect which cloud belt. Under this heating influence would be occasioned by a greater or less the clouds “melt away and become invis- amount of moisture. ible;” the sun's rays dissolving one set of As an example of drainage that has elevations, and creating another set of de- been cut off, and an illustration of the pressions. Were this cloud ring luminous, process by which precipitation and evaporand seen from one of the planets, it would, ation are equalized, our author takes the according to Lieut. Maury, resemble the case of the Salt Lake of Utah, the basin of Ring of Saturn, the side which is opposite which is now salting up, and from which us appearing “jagged, rough, and un- there is said to be the appearance of an even;" and it would seem to have a mo-old channel which once conducted its tion contrary to that of the earth.
waters to the sea. If such a river existed, In exploring the physical geography of some cause must have operated to stop the sea, our author accompanies the geo- the supply of moisture, the excess of which logist “far away from the sea-shore” to was carried off by the river. Our author study the phenomena presented by the conceives that if the Sierra Nevada, the inland basins of the earth, the Dead Sea, mountains to the west of the lake, now the Caspian, the Lake of Aral, etc., which stand higher than they formerly did, and have no sea drainage, and he proposes to if the winds which fed the Salt Laké val. explain their present condition by what he ley with moisture had to pass over the calls“ the geological agency of the winds." mountains, a less quantity of vapor would The Dead Sea, the most interesting of be carried across them than when the sumthese basins, is 1500 feet beneath the gen- mit of the range was lower and warmer. eral sea level of the earth. The geologist In like manner, our author supposes that refers this remarkable depression to forces the Dead Sea, and the great inland basins of elevation or subsidence which have re- of Asia, may have been deprived of the sided in the vicinity of the basin; but vapor which they once received when Lieut. Maury supposes, and endeavors to they were emptied by rivers into the sea, show, that these forces have come from by the elevation of the South-American the sea in the other hemisphere, through continent, and the upheaval of its mountthe agency of the winds. He supposes ains. The elevation of the Andes has that the amount of precipitation (of rain, thus made Western Peru a rainless counsnow, dew, etc.) upon the water-shed of try, and Atacama a desert, by stopping the Dead Sea, etc., was, at some former the vapors of the ocean which fed them period greater than its present annual with moisture; and in the opinion of amount of evaporation, and he asks, from Lieutenant Maury, who adduces various what part of the sea did that excess of ingenious arguments in support of it, it is vapor come? and what has cut off that the influence of the same range that has supply, since the amount of evaporation is depressed the waters of the inland basins equal to that of precipitation, and the of Asia. According to geological speculevel of this and other rock seas is as per-. lations, the upheaval of one continent is manent as that of the ocean? If the supposed to be accompanied by the deDead Sea formerly sent a river to the pression of another, as exhibited in the ocean, it would carry off the excess of islands of the Pacific; and therefore, if we precipitation over the vapor raised, and adopt the views of our author, we must carried away by the winds. According take it for granted that no continent was to our author, " the salt-beds, the water depressed to the west of the Dead Sea marks, the geological formations, and when South-America rose from the ocean. other facts traced upon the tablets of the If the winds have the geological agencies rocks, indicate plainly that the Dead Sea now ascribed to them, our author conceives and the Caspian had upon them in former that they may instruct us in the chronoperiods more abundant rains than they logy of geological events which have taken now have;" and he is of opinion that the place in different hemispheres, " telling us supply has not been cut off by the eleva- which be the older—the Andes watching the stars with their hoary heads, or the tom at 34,000 feet. Lieutenant Berry. Dead Sea sleeping upon its ancient beds man failed also in “mid ocean? with a of crystal salt."
line 39,000 feet in length; and Lieutenant The “Depths of the Ocean," whether Parker, in the same region, ran out a line they underlie the pure azure of the Indian 50,000 feet long without reaching the seas, or the troubled current of the Gulf bottom. In order to solve the interestStream, or the tangled sea-weeds which ing problem of the sea's depth, the Conmat the Sargasso Sea, have a peculiar in- gress of the United States authorized the terest to the naturalist. While the land employment of three public vessels; and, is the abode of vegetable, the sea is the after the investigations were completed, home of animal life. In the sea bottoms, the following plan was adopted : Every indeed, of the temperate zones, vegetation vessel that desires it is furnished with a is peculiarly luxuriant; but in the tropical quantity of sounding twine, (600 feet to oceans the grandeur and abundance of the pound,) marked at every length of marine life is more prominent still. 600 fathoms, and wound on reels of 10,000 “Whatever is beautiful, wondrous, and fathoms each. One end of the twine is uncommon in the great classes of fish and attached to a cannon ball of 32 or 68lbs., echinoderms, jelly-fishes and polypes, and as a plummet, which is to be thrown overmolluscs of every kind, is crowded into board from a boat, (not from the ship,) the warm and crystal waters of the tro- and suffered to uncoil the twine as fast as pical ocean-rests in the white sands, it will. When the ball reaches the botclothes the rough cliffs, clings where the tom, it is detached, and of course lost. room is already occupied, like a parasite, By measuring the quantity of twine left upon the first comers, or swims through on the reel, and subtracting it from the the shallows and depths of the elements, whole length, we have the required while the mass of the vegetation is of a depths of the sea," at the expense of one far inferior magnitude.* On land, the cannon ball and a few pounds of common animal kingdom is more widely diffused twine." than the vegetable; but the Arctic seas In carrying out a system of deep-sea swarm with whales, seals, sea-birds, fishes, soundings, it was the practice to record and countless numbers of the lower ani- the time taken by every hundred fathoms mals, even where the ice has obliterated to be uncoiled from the reel-a reel of every trace of vegetation. As we de. the same size and “make,” and sinker or scend, too, from the surface, vegetable cannon ball of the same shape and weight, life disappears much sooner than animal; being always used. By this means the and from its hollows, which no ray illumes, following law of descent was established : the sounding lead attests the abundance of living infusoria.
Average Time of descent. Number of Feet descended. 2 min, 21 sec.
2,400 to 3,000 While almost every corner of the land
6,000 6,600 had been visited and explored by man,
10,800 “ 11,400 the bottom of what the sailors call blue water was utterly unknown to us. Eng. As the under-currents in the ocean would lish, French, and Dutch navigators had sweep the line out horizontally at an uniattempted to fathom the deep sea, but form rate, while the cannon ball would their methods could not be relied upon drag it down at a decreasing rate accordbeyond depths of eight or ten thousand ing to the preceding law, the observer feet; and even after great improvements was able to discover when the line was had been made on the sounding apparatus carried out by the influence of the current in the United States, it was found that or drift alone, and thus to determine the under-currents prevented the lead from true depths at which experiments were reaching the bottom, by carrying it out made. In this way it was placed beyond in the direction of the current. That this a doubt, that the depth of the sea was not was the case, was proved by direct ex- so great as it had been found to be by the periment. Lieutenant Walsh, of the U.S. imperfect methods formerly employed, Navy, with an iron wire sonnding-line and that the greatest depths which had eleven miles long, could not find the bot. been reached were in the North-Atlantic
Ocean, and did not exceed 25,000 feet, or * Schleiden's "Lectures," p. 403, quoted by Lieut four miles and three quarters. The deepMaury.
est place in the ocean is considered by
Lieut. Maury to be between the parallels | across its bottom, from Cape Clear in of 35° and 40° of north latitude, immedi- Ireland, to Cape Race in Newfoundland, ately to the south of the Grand Banks of a distance of one thousand six hundred Newfoundland.
and forty miles! Between these capes Having thus succeeded in reaching the there is a remarkable steppe or ridge, bottom of the sea, an additional contriv. already known as the Telegraphic Plateau, ance was required to bring up specimens above which there is not more than 10,000 of the materials of which it was composed, or 12,000 feet, or two miles of water. A This was accomplished by Mr. Brooke, of company of enterprising and wealthy inthe U. S. Navy, by means of his “Deep dividuals has already been organized to Sea Sounding Apparatus.” At the end carry a submarine cable across this plateau, of the tubular iron rod which passes and they have made a contract with a party through the cannon ball sinker, is placed in England to deliver to them in June, 1858, a cup containing a little soap or tallow, a telegraphic cable of the required length; called arming, to which the specimens of and, notwithstanding the failure of their the sea-bottom adhere, and are brought up, first attempt, we can not doubt that it after the ball has been detached from the will be ultimately successful. rod. By means of this apparatus, speci- In connection with this elevated ridge mens have been obtained from depths of across the Atlantic, there is a ridge on more than three miles-some from the the land “which runs nearly, if not enCoral Sea of the Indian Archipelago, and tirely, around the earth. ” Leaving some from the Pacific and Atlantic Oceans. America between 45o and 50° N., it in.
Among the sea basins of the ocean, that cludes Great Britain, separates the drainof the Atlantic, the most frequented, has age of the Arctic Ocean from the draina peculiar interest, and is the subject of a age southwards, and forms a chain of long and interesting chapter in the steppes and mountains extending across “Geography of the Sea.” Lieut. Maury the continent of Asia, and disappearing in has given us an orographic projection of the Pacific. It was in the subaqueous its bottom, in which the soundings are part of the ridge that Brooke's sounding represented by four different degrees of apparatus brought up calcareous shells of shade. The darkest, which is nearest the the Foraminiferæ, while in the Coral Sea shore line, indicating depths less than the silicious infusoria and the Polytha6000 feet; the next, those less than 12,000 lamia were obtained; and more recently feet; the third, those less than 18,000 feet; Lieutenant Berryman has found obsidian, and the fourth, or lightest, those not pumice, etc., forming a line of volcanic greater than 24,000 feet. From the blank cinders a thousand miles long, and space north of Nova Scotia and the Grand stretching wholly across the Gulf Stream Banks of Newfoundland, very deep water where the submarine cable is to be laid. has been reported. The deepest part is Lieutenant Maury and others have found probably between the Bermuda Isles and it difficult to determine the source of the Grand Banks. In another plate Lieut. these volcanic materials. Occupying a Maury has given a vertical section of the line so extended, it is not unreasonable Atlantic, showing the contrasts of its bot- to suppose that submarine' volcanoes tom with the sea-level in a line from were situated in or near the place Mexico, across Yucatan, Cuba, San Do- where their products have been found. mingo, and the Cape de Verd Islands, to The specimens of animalcular life obtained a point in the coast of Africa, in the from various seas place it beyond a doubt parallel of 16° of north latitude. The im- that the bed of the ocean is a vast cemeportance of this system of deep-sea sound- tary consisting almost entirely of the re. ing has been recently impressed upon the mains of infusoria ; and the unabraded public mind, and may be regarded as one appearance of these shells, and the almost of the many proofs constantly presenting total absence of any sand or other matter, themselves, that there is no branch of seems to show that the bottom of the physical knowledge which will not sooner deep sea is in a state of perfect repose. or later find a practical and social applica- Although our author, in his chapters on tion. In the soundings of the North- the Atmosphere, and on Land and Sea Atlantic Ocean, the bold engineer who Breezes, has treated generally of the Trade has faith in the resources of science, has Winds, etc., and the Calm Belts which seen the practicability of laying a cable limit them, he devotes a long and valua