Brackish water

“ It is quite possible that, when the lagoon became too saline, they withdrew into the brackish water zone of estuaries or deltas. This inference agrees well with the meagerness of the marine brachiopod and mollusk fauna with which they are associated, the brackish water being still today the least inhabited zone of the hydrosphere on account of its frequent changes in salinity; and it is also in full accord with the occurrence of the eurypterids in the Devonic rocks. There is no longer any doubt that the Stylonurus of the Catskill beds inhabited an estuary with brackish water conditions ”

“ The fresh-water forms are specifically distinct from those incidental to salt or brackish water,—fresh-water species, however, are sometimes carried some distance into the sea by the force of the current, and in tidal rivers marine forms are carried up by the force of the tide. ”

“ Such an additional quantity of water as their interpretation requires, would so dilute and alter the mass as to render it an unsuitable element for the existence of all the classes, and would kill or disperse their food; and all have their own appropriate food. Many of the marine fishes and shell animals could not live in fresh water; and the fresh water ones would be destroyed by being kept even a short time in salt water. Some species can indeed live in brackish water, having been formed by their Creator to have their dwelling in estuaries and the portions of rivers approaching the sea. ”

“ This same most accurate observer finds, however, that B. balanoides is very susceptible to brackish water; he says, “that having kept some specimens alive for a week in excellent health, the water being changed once in thirty-six hours, they were one day killed instantly by some water, though brought from the same part of the estuary as usual, having been rendered brackish by much rain having lately fallen.” I may recall the fact, that B. improvisus lives daily for hours in absolutely fresh running water. ”

“ The Brachyura (or Crabs) include many species that live [180] in fresh water. Some of these, like the species of Sesarma (see Plate XXIII.) and some other genera of the family Grapsidæ, are common throughout the tropics, passing up the rivers from the brackish water of estuaries, and being often found long distances inland in quite fresh water. The true River Crabs, however, belong to the family Potamonidæ, and are very common throughout the warmer regions of the globe. ”

“ Mankind.—Even man can acquire a partiality for salt or brackish water. Barrow relates that an old man in the Bokkeveld of South Africa, "who from his infancy till a few years past had lived in Zwartland, never missed an opportunity of sending thither a few bottles to be filled with the briny water for his own particular use ”

“ We are among the olive-coated stones at the verge of the far-receded tide, among which the springs from the cliffs having broken out from various points in the shingle beach, are making for themselves tortuous channels on their way to the deserting sea. Their water, originally fresh of course, has, by the time it arrives here, become so brackish by washing the salt stones and sea-weeds, that the sand-hoppers and worms which inhabit the hollows under the stones are bathed in it with impunity, though, in general, immersion in fresh water is fatal to marine animals. ”

“ So, if a tract of salt water becomes fresh by passing through every intermediate degree of brackishness, still the marine mollusks will never be permitted to be gradually metamorphosed into fluviatile species; because long before any such transformation can take place by slow and insensible degrees, other tribes, already formed to delight in brackish or fresh water, will avail themselves of the change in the fluid, and will, each in their turn, monopolize the space. ”

“ What may be termed composite breakwaters are partly sloping and partly vertical, and act by causing the waves to break, and also by partially reflecting them seawards or deflecting them laterally. The new breakwater at Aberdeen and the Dover Admiralty pier, which acts also as a breakwater, are examples of the first class. Plymouth breakwater, which rises with a general sea-slope of from 2 to 5 horizontal to 1 vertical to a height of 23 feet above high water, is an example of the second class. ”

“ Sometimes we spend our afternoon or evening out at the end of the breakwater, which forms one side of this little mariner's refuge. It connects a rock which stands right out at sea, with the shore, and occasionally in spring-tides is quite under water. One evening, while standing on the far end watching the glorious setting sun, we forget to look behind us, and turning suddenly, find the breakwater submerged. A man could still cross it perhaps, but a not over-strong woman might easily be carried over and drowned by the on-coming surf. ”

“ The spruits or brooks run low in their beds, the ditches are dry, the wells have only a bucketful of muddy water and a good many frogs in them, and the tanks are failing one after another. Yet this is only the beginning of winter, and I am told that I don’t yet know what dust and drought mean. I begin to think affectionately of those nice heavy thunder-showers every evening, and to long to see again the familiar bank of cloud peeping up over that high hill to the west, precursor of a deluge. Well! well! there is no satisfying some people. ”

“ In the dry season the evaporation, of course, increases the strength until the water can no longer retain the amount of salt in solution it therefore precipitates and crystalizes at the bottom in various degrees of thickness, according to the strength of the brine.
Thus, as the water recedes from the banks by evaporation and the lake decreases in size, it leaves a beach, not of shingles, but of pure salt in crystallized cubes, to the depth of several inches, and sometimes to half a foot or more. The bottom of the lake is equally coated with this thick deposit. ”

“ The water of the Bering Sea was a deep blue-black, thought the Major, and he watched carefully the ship-made waves: black when with the sea mass, then varying shades of clear blue as they swept up into the large waves, exploding at last in sudden whiteness. When he had the time, Major Barkison appreciated beauty. ”

“ The tide flows up the river many miles past the waterworks, carrying up with it the filth from the sewers. The supply of water was, to be sure, obtained when the tide was down, but as the banks of the river are clothed with sedges in many parts, and its bottom deep with mud, the water can never be free from sewage. ”

“ Into one of the nozzles, when the tide comes over it, is constantly sucked a current of sea-water which passes into a stomach-like cavity, where the minute particles of food in the water are caught and digested; then the water passes on through another cavity where the blood receives its oxygen, as in our lungs or a crab's or fish's gills, and then rushes out. ”

“ Its colour was of the purest azure, and so clear that the shadows of the mountains that bordered the horizon were reflected on it with the greatest precision, and the delusion of its being a sheet of water was thus rendered still more perfect.” This mockwater, however, only served to heighten the terrors which the scarcity of real water excited. Every man now began to attach the greatest importance to the small stock he possessed. Burckhardt, who possessed but two draughts of water in the world, drank the moiety of it at once, reserving the remainder for the next day ”

“ Bob jumped to his feet. “Look here. We can’t sit here idle, waiting to be tossed toward one bank or the other, while all the time we may be skidding along toward a falls. I can’t hear any roar indicating one near at hand. Just the same, this river is running mighty fast, and there may be a falls ahead. Let’s get some of these poles together and try to rig up a stern sweep to guide us inshore.”
“That’s the idea,” approved Frank. “It’s about our only chance to save the raft, and if we don’t do it we may soon all be in the water trying to swim to shore.” ”

“ The over flow now becomes very gentle and even over the entire rim. The atmosphere reaches the whole of the overflow as it spreads over the surface of the ground and causes rapid precipitation. The constant outpour causes a constant lifting of the pool and of the incrustations about it. This spreading crust is in laminae or thin sheets. As the pool rim lifts, the weight of the column of water forces some of it between the sheets and carries it hot and rich in mineral and earthy solid matter to the outer edges of the formation, where it escapes to spread the incrustation wider and wider. ”

“ The digestive system of a brachiopod includes an œsophagus that leads into a simply formed stomach round which is a large digestive gland. The heart has only one cavity, but the animal is provided with two smaller and separate organs that assist in the propulsion of the blood, which circulates through numerous blood spaces in the bristly mantle.
About two thousand fossil species of brachiopods are known, extending over a vast range of time; and the living species, numbering less than a hundred, are found from shallow water to the greatest habitable depths. ”

“ The flux and reflux, when seen were quite regular. Every flood began gently, its velocity increasing by degrees, until at length it rushed in with great impetuosity, till it had attained its full hight. Having remained for a little time stationary, it then retired, ebbing gently at first, but afterward sinking away with great swiftness. At every flux the whole body of water seemed to be violently thrown against the bank; but neither during the time of the flux, nor that of the reflux, did there appear even the least wrinkle of a wave on the other parts of the moat. ”

“ There was nothing out there in the water but darkness. Even the deep-sea fish had felt the impulse and avoided the sub. Fallon got up.
"Bjarnsson," he said, "I'm going to sleep."
The explorer half turned in his seat.
"Ja?" he said quietly.
"There's nothing out there," growled Fallon. "Why should I sit and glare at that periscope?"
"Because," Bjarnsson returned with ominous gentleness, "there might be something. We will not reach the volcano for perhaps ten hours. You had better watch." ”

“ It is therefore essential, before constructing a breakwater, to investigate most carefully the force, periods and duration of the winds from the quarters to which the work will be exposed, the distance of any sheltering land from the site in the most stormy direction, the slope of the beach and the depth of the sea in the neighbourhood of the shore, and the protection, if any, afforded by outlying shoals or sandbanks. In a tidal sea, the height required for a breakwater is affected by the amount of tidal range ”

“ Brecknock Harbour is six miles deep, extending gradually from a width of one and three quarter miles at the entrance to five at the head, and has a depth of water varying from five to seven fathoms, with a soft muddy bottom. The few observations on the tides our short visit afforded, make the time of high-water, on full and change day, about half an hour before noon, when the rise is nearly thirty feet, and the strength of stream in the entrance nearly two knots. ”

“ Three hours later it appeared again. The return tide had washed it back, and a little later a larger wave than usual carried it on to the rough stones of the unfinished Breakwater, where it held fast. The water receded, and the four unhappy voyagers crept out on to the rocks, to be rescued half an hour later by a pilot boat. Such was one of the unexpected services rendered by the Breakwater at Plymouth; but its expected benefits, worthily accomplished, have been too numerous to record.
John Lea
"The weight of the two birds had the desired effect." ”

“ The flow of water in the river had been perceptibly increased by tributaries, and now, after each mill, the current was strong enough to take us down for a mile or two at a quick rate. The little boat danced gaily in the rapids. The great heat of the day had gone, and the light was waning, when we mistook an arm of the river for the main stream, and found ourselves at length in a little gully, very dim with overarching foliage, and where the sound of rushing water grew momentarily louder. ”

“ Out of the woods, the brook dashes down a steep incline until the foaming tide comes to rest in a deep pool. What becomes of the large pebbles which have been swept down? Do they go on or do they stop? If you go to the outlet of the pool you will see that the water is coming out with nothing in its grasp but the fine clay and sand, the gravel and pebbles having been dropped by the less rapid current of the pool. This is one of the most important of the brook's lessons, for anything that tends to check the current makes it drop some of the sediment that it carries (Fig. 44) . ”

“ More than half of them were full—full to the very bung.
But what were they full? That was the serious question. Of fresh-water? No. The appalling discovery that had been made was, that the water within them was salt! in fact, water out of the sea itself, salt as brine!
This was indeed a fearful discovery; but it was easily explained. It was known from the beginning that these butts had been filled with salt-water—to serve as ballast on the out voyage from England; and the intention had been to empty them all into the African river and substitute fresh-water instead. ”