Submersible

“ If the large submerged float is made of very nearly the same density as water, then it is liable to be thrown upwards by very slight eddies in the water, and it does not maintain its position at the depth at which it is intended to float. On the other hand, if the large float is made sensibly heavier than water, the indicating or surface float must be made rather large, and then it to some extent influences the motion of the submerged float. Fig. ”

“ But if we have no perfectly certain ideas regarding the propagation of the motions of the sea in depth, we can assert, that, whatever that extent and that power may be, the submarine currents no more abrade the rocks than rivers do the surface of the land. ”

“ Having lungs not adapted to a watery medium, but to the nature of atmospheric air, it would be impossible for them to pass through the volume of waters that intervenes between the submarine and supramarine world, if it were not for the extraordinary power they inherit of entering the skin of some animal capable of existing in the sea, which they are enabled to occupy by a sort of demoniacal possession. ”

“ Now, if you will shew that besides the former Cause, there is another which is so powerfull, that it can hinder and remove the Submersion of those very Solids, that by their Gravity sink, and if you will say, that this is the breadth or ampleness of Figure, you are oblieged, when ever you would shew such an Experiment, first to make the circumstances certain, that that Solid which you put into the Water, be not less grave in specie than it, for if you should not do so, any one might with reason say, that not the Figure, but the Levity was the cause of that Natation. ”

“ It seems to me absolutely true, that our world, which appears to us the surface of all things, is really the bottom of a deep ocean: all our trees are submarine growths, and we are weird, scaly-clad submarine fauna, feeding ourselves on offal like shrimps. ”

“ There are certain great holes in great rocks by the sea into which the water enters through submarine channels and creeps up and up, increasing its bubbling and its seething, as the flood fills the natural well until when the top is reached there is a boiling caldron. ”

“ Doctors Leonard Hill and Greenwood, of the London Hospital Medicine College, have conducted a series of scientific investigations regarding the physical limits of a normal man to compression without risk of strain or ultimate injury. Remarkable as it seems, they have shown that it is possible to submit to a pressure of seven atmospheres—the equivalent of a submergence to a depth of two hundred and ten feet, a depth considerably in excess of the best diving records up to the time of their experiments. ”

“ But while they lived, always submerged, always beneath the wave. Beneath the wave they might have powerful roots, stronger than iron; they might be tenacious and dangerous in their soft waving within the flood. ”

“ When dealing with real liquids not entirely free from viscosity, such resistance as does exist is due, as already mentioned, to skin friction and eddy formation. In the next place, leaving the consideration of the movement of wholly submerged bodies through liquids whether perfect or imperfect, we shall proceed to discuss the important question of the resistance offered by water to the motion through it of a floating object, such as a ship or swan. We have in this case to take into consideration the wave-making properties of the floating solid. ”

“ This opinion is, however, untenable; for the sinking down of the bed of the ocean is one of the means by which the gradual submersion of land is prevented. The depth of the sea cannot be increased at any one point without a universal fall of the waters, nor can any partial deposition of sediment occur without 564 the displacement of a quantity of water of equal volume, which will raise the sea, though in an imperceptible degree, even to the antipodes. ”

“ I will farther confirm this which I say. Gentlemen, my Antagonists, we are agreed, that the excess or defect of the Gravity of the Solid, unto the Gravity of the Water, is the true and proper Cause of Natation or Submersion. ”

“ Which operation followes the Submersion and sinking; and this it is, How the submersion of Solids in the water is effected.That in the Submersion that the Solid maketh, being depressed downwards by its proper Gravity, it comes to drive away the water from the place where it successively subenters, and the water repulsed riseth and ascends above its first levell, to which Ascent on the other side it, as being a grave Body of its own nature, resists: And because the descending Solid more and more immerging, greater and greater quantity of Water ascends, till the whole Sollid be submerged ”

“ How infinitely greater, therefore, would be the action of the waters over all the materials subject to their disintegrating power, whether upon the islands and continents already raised above their waves, or upon the immense submarine tracks of rock just lifting up their peaks and waiting to be elevated into air? ”

“ This drains off from the surface, forming rills, which collect as they descend, by their own weight, into the lowest channels of the ground, and form into streams and rivers, and back into the sea comes the water which the air had taken away, with this difference, that it is free from salt and fit for the many uses to which fresh water alone can be applied; when the vapour rises from the sea, none of the saline matters rise with it, for, although the water is volatile, yet they are not, and this is the whole source of fresh water. ”

“ To satisfie all I may, to all doubts, I have been considering how by some other sensible Experiment I might demonstrate, how truly that little contiguous and superiour Air sustaines those Solids, which being by [Pg 39] nature apt to descend to the Bottom, being placed lightly on the water submerge not, unless they be first thorowly bathed ”

“ If we consider the rock as a mass completely saturated with water through a certain vertical depth, the water being in a state of equilibrium, when a well is sunk, and the water pumped up, the state of equilibrium is destroyed, and the water in the rock is forced in from all sides. ”

“ The chance will be less if the submarine surface, instead of having remained stationary, shall have gone on slowly rising during the deposition of the strata, for in this case their total thickness must be less, and each part, before being consolidated or thickly covered up by superincumbent matter, will have had successively to pass through the ordeal of the beach; and on most coasts, the waves on the beach tend to wear down and disperse every object exposed to their action. ”

“ When water boils under the conditions of our ordinary experience, the passage from the liquid to the gaseous state is a sudden leap, with no intermediate state of existence that we are able to perceive; and the conditions upon which water is converted into steam—the liquid into the gas—while both are at the bottom of our atmospheric ocean, are such as to render an intermediate condition rationally, as well as practically, impossible. ”

“ I thought it would be possible to remain submerged only a short time unless I provided some sort of apparatus to extract the carbonic acid gas and restore oxygen to the air after breathing and exhaling the air in an enclosed space like a submerged vessel. I took up the question with various physicians and with a professor of physiology at Johns Hopkins University, and, according to their information and text-books, it would be a very difficult matter to carry sufficient air to remain submerged without change of air except for a very short time. ”

“ For if there is one thing considered constant in this changing world of ours, it is the level of the sea. All our heights and depths are compared to and computed from it, so unchanging do we esteem it; since though great tides may come and go the level of the sea itself seems never to change, so delicately balanced are the combined processes of evaporation and condensation which deplete and replenish it. And for this hitherto unchanging level to rise suddenly for almost three feet, in as many days, was a phenomenon of intense interest and mystery. ”

“ No serious ship-constructor would nowadays think of adopting this method of submersion, and we may therefore pass on to consider those which are brought to the submerged condition by the admission of water into special reservoirs or tanks.
Submarine boats so far as their immersion is concerned may be divided into two classes.
1. Those which when submerged possess no floatability.
2. Those which in the same condition possess a small reserve buoyancy or floatability. ”

“ The explanation, of course, is simple. The brine is of greater specific gravity than the pure water; the pressure of the heavier fluid forces the lighter up in the tube. This action continues until, as you will see by this experiment, in the gradual diffusion of brine and pure water the salt is disseminated equally throughout the vessels, and the specific gravity of the mixed liquid becomes the same throughout, when the flow will cease. However, in the earth, where supplies are inexhaustible, the fountain flows unceasingly. ”

“ I, with a different Method, and by other meanes, will endeavour to demonstrate the same, reducing the Causes of such Effects to more intrinsecall and immediate Principles, in which also are discovered the Causes of some admirable and almost incredible Accidents, as that would be, that a very little quantity of Water, should be able, with its small weight, to raise and sustain a Solid Body, an hundred or a thousand times heavier than it. ”

“ A little farther out, the sea breaks more roughly over submerged rocks, and the waves lift themselves, ere breaking, in an indescribable way, as if each gave a glimpse through a translucent window, beyond which all ocean's depths might be clearly seen. ”

“ Nay, in the very same solid Vessel, you may make the very same two contiguous Liquids to alter their Surfaces; for taking a small Wine-glass, or such like Vessel, and pouring water gently into it, you shall perceive the surface of the water all the way concave, till it rise even with the top, when you shall find it (if you gently and carefully pour in more) to grow very protuberant and convex; the reason of which is plain, for that the solid sides of the containing body are no longer extended, to which the water does more readily adhere then the air ”

“ When immersed and inflated, they remove a quantity of water adequate to the air which they contain, and, if fixed to a ponderous body, give it a degree of buoyancy proportionate to the water they displace. ”

“ The hydrostatic force with which the water, in virtue of its specific gravity, presses against the banks that confine it, has a tendency to sustain them whenever their composition and texture are not such as to expose them to softening and dissolution by the infiltration of the water. ”

“ Perhaps the most weird of these attempts, and the most intensely interesting, so long as the verisimilitude is maintained, is a dream adventure in a drop of water which, through an incredible human reduction to microbic, even atomic, proportions, has become a vast tempestuous sea. ”

“ SUBMARINE NAVIGATION
As was explained in Chapter VI, a body will float only so long as it is lighter than the volume of water it displaces. It is almost impossible to keep a body suspended in water unless some portion of it is exposed above the surface. If it starts sinking it will keep on going down until it reaches the bottom of the sea. ”

“ Also the exterior and outward shape or form makes some bodies more apt to sink then others; Indeed, the outward form and shape of Creatures is one of the chief causes of either sinking or swimming. But to conclude, water in its interior nature is of a mean or middle degree, as neither too rare, nor too grave a body; and for its exterior quality, it is in as high a degree for wetness, as fire is for heat; and being apt both to divide, and to unite, it can bear a burden, and devour a burden, so that some bodies may swim, and others sink ”

“ We would, therefore, be understood to ascribe this anomaly in the flowing and ebbing of the sea, to the obstruction which the current of its waters meets not only at the surface or margin, but at the bottom, which, from the variety of the soundings of the depths, appears to be as various as the face of the land. ”

“ In deep places the pressure of the sea-water on them is very great, sufficient to force water through glass. Obviously most of these bottoms will leak, and leak at a rapid rate under the enormous pressure operating in the greatest depths of the sea. The bed of the ocean will not leak with equal rapidity in all places; but almost universal leakage will certainly develop, and the water will be driven back into the earth at various rates. ”

“ The oceanic waters are in fact separated from the viscous substratum by no more than a thin layer of solid earth, a mere skin in comparison with the size of the planet. Further, this 'drop' of liquid which represents the earth is in constant communication with its environment through the perpetual evaporation from the ocean, as well as from every other body of water. ”

“ For many years scientists maintained that in such depths no life could exist, since no bodies could withstand the awful pressure. Yet we now know that frail jelly-fish, fragile shell-inhabitants, do withstand it, flourishing there by myriads.
Perhaps the fact was somewhat overlooked, that the pressure upon a living creature is not only inwards from without, but also is outwards from within. This is true of ourselves in the ocean of air, breathing air. It is true of creatures in the ocean of water, breathing water. ”