The Book of Curiosities

by John Platts

M. Dassie has been at great pains to prove, that the sea has a general motion, independently of winds and tides, and that it is of more consequence in navigation than is generally supposed. He affirms, that this motion is from east to west; inclining towards the north, when the sun has passed the equinoctial northward, during the time he is passing through the northern signs; but the contrary way, after the sun has passed the said equinoctial southward: adding, that when this general motion is changed, the diurnal flux is changed also; whence it happens, that in several places the tides come in during one part of the year, and go out during the other, as on the coasts of Norway, in the Indies at Goa, Cochin-china, &c. where, while the sun is in the summer signs, the sea runs to the shore; and when in the winter signs, runs from it. On the most southern coasts of Tonquin and China, for the six summer months, the diurnal course runs from the north with the ocean; but the sun having repassed the line toward the south, the course declines also southward.

There are two principal reasons why the sea does not increase by means of rivers, &c. falling every where into it. The first is, because waters return from the sea by subterranean cavities and aqueducts, through various parts of the earth. Secondly, because the quantity of vapours raised from the sea, and falling on the land, only cause a circulation, but no increase of water. It has been found, by calculation, that in a summer’s day there may be raised in vapours, from the Mediterranean Sea, 5,280,000,000 tons of water, and yet this sea receiveth not, from all its nine great rivers, above 1,827,000,000 tons per day, which is but a third part of what is exhausted in vapours.

The ascent of the sea for the formation of springs, by a subterranean circulation of its water to their sources, has been a great objection, with many, against the system which ascribes their origin to the ocean; but Dr. Plot has observed, that there are many ways by which the water may ascend above its own level: 1. By the means of subterranean heat. 2. By filtration. 3. By the unequal height of several seas. 4. By the distance of the centre of magnitude from the centre of gravity in the terraqueous globe; the superficies of the Pacific Sea being said to be further from the centre of gravity than the top of the highest hill on the adverse part of the globe. And, 5. By the help of storms. The sea water actually ascends above its own level, and finds its way into wells, whose bottoms lie higher than the surface of the sea at high-water mark.

We shall now enter more particularly on The Curiosities of the Sea.—For the following observations we are principally indebted to Sturm.

“Instead of regarding the sea as an object of terror, let us consider the wonders and the benefits which it presents to us. It must be granted that when the waves swell into mountains, and the tempest roars, its aspect is terrific; and we must be hardy indeed, not to consider it as a most formidable element in such times of awful visitation, when ships, breaking from their anchor, or driven from their course, rush before the winds that beat upon them with ungovernable fury, till, dismasted, and their rigging shivered in fragments, they sink, overwhelmed with a weight of waters, or strike some sand-bank, or shelving rock, and are at once dashed to pieces. Sometimes whirlpools, or vast masses of water with a violently circular motion, whirl the unfortunate vessel that fate urges into their vortex, with irresistible force, till the helpless victim sinks an easy prey to the tremendous gulf, and the cries of the unfortunate wretches are lost in the roar of the waves: these whirlpools are occasioned by rocks in the ocean, and the meeting of numerous currents and eddies. Not less dangerous are the waterspouts, that the wind raises from the sea to the clouds; they hover in the air high above the ocean, and the wind whirls them round with violence. They often burst with a great crash, and occasion much mischief; for if they fall upon a vessel, they destroy its rigging, and sometimes sink it to the bottom.

“But it would be highly unjust and ungrateful, only to consider the losses occasioned by the sea, without reflecting upon the magnificent and stupendous works of God, and that goodness which even visits the unfathomable depths of the ocean. The first thing that strikes us, upon the investigation of sea water, is its saltness; a pound of the water containing about two ounces of salt. Sea salt appears lighter than that we commonly use, and yet it is not attracted by the air, nor lessened by the continual influx of fresh water; the cause of this is unknown. If this peculiar quality arose from mountains of salt contained in the sea, it would be salter in some places than in others, of which we have no proof. But whatever is the occasion of this saline property of the sea, it is absolutely necessary to accomplish certain ends. It is that which preserves such a vast body of water from corruption, and renders it capable of supporting a greater weight. The colour of sea water is also deserving of attention: it is not every where alike, which perhaps arises in part from its reflecting the colour of the bottom and that of the sky. It often appears dark and black in deep abysses, white and foaming during a storm, silvery, and gilded with reflections of the most beautiful hue, when the last rays of the setting sun play upon the unruffled surface: the colour of the sea, in addition to these, varies, from numberless insects, marine plants, and the combination of the different substances which the rivers and torrents carry with them into the ocean. When it is calm, and not a breeze skims over its bosom, it sometimes glitters with the most brilliant stars; and the track of a ship cleaving the waves has often a luminous appearance, like a river of fire.

“The creatures which inhabit the sea excite our surprise and admiration; we there discover a new world, and the number of beings which compose it is prodigious. Aquatic animals are not so numerous in their species as the land animals; but they surpass them in size and duration. The elephant and ostrich yield in bulk to the whale, the largest fish of the ocean, its length being often from sixty to seventy feet; and no land animal can vie with it in longevity, for it lives as long as the oak. If we may rely upon certain accounts, there are creatures in the ocean, far exceeding the size of the whale; as the animal called kraken, said to exist in the northern seas, and whose circumference is half a German league. Who is able to number the different species of animals which people the seas? or who can determine their form, structure, size, and properties? How infinitely great is that God who has created the sea! will be the conclusion of all who investigate the subject, and it is not without the wisest reasons that the Creator has made the ocean and the seas to occupy two-thirds of the whole globe. The seas were designed not only to form great reservoirs of water, but by means of their evaporation to be the sources of rain, snow, and various meteors. What wisdom is displayed in the connection which the seas have with each other, and in their continual motion! And it is not less wonderful that the bottom of the ocean is of the same nature as the surface of the earth. There are found in the sea, rocks, caverns, plains, springs, plants, and animals; and the islands are only the summits of a long chain of mountains. When we consider that the seas form a part of the globe the least investigated, we are disposed to believe that they contain many more wonders, which neither the senses nor the understanding of man can penetrate, while all acknowledge the adorable wisdom and power of the Most High. To Him then, who has established the monuments of his grandeur and the sceptre of his glory in the ocean, as upon the earth, be ascribed all admiration and praise!”

The following opinions of a late celebrated philosopher and divine, on the Saltness of the Sea, may not be unacceptable to our readers:—“There are few questions, (observes Bishop Watson,) respecting the natural history of our globe, which have been discussed with more attention, or decided with less satisfaction, than that concerning the primary cause of the saltness of the sea. The solution of it had perplexed the philosophers before the time of Aristotle; it surpassed his own great genius; and those of his followers, who have attempted to support his arguments, have been betrayed into very ill-grounded conclusions concerning it. Father Kircher, after having consulted three and thirty authors upon the subject, could not help remarking, that the fluctuations of the ocean itself were scarcely more various than the opinions of men concerning the origin of its saline impregnation. The question does not seem capable of admitting an illustration from experiment; at least no experiments have hitherto been made for that purpose, and therefore we may be the less surprised at its remaining nearly as problematical in the present age, as it has been in the preceding. Had there, indeed, been any observation made three or four centuries ago, ascertaining the saltness of the sea at any particular time and place; we might, by similar observations at the same place and the same season, have been able to know whether the saltness at that particular place was an increasing, decreasing, or an invariable quantity; and this kind and degree of knowledge would have served as a clue to direct us to a full investigation of this matter in general; but it is to be regretted, that no such observations have, till very lately, been made with any tolerable precision.—There are three principal opinions on this subject, which have been maintained by philosophers of modern date; some, observing that river water, almost in every part of the globe, is in a greater or less degree impregnated with sea salt, have thought that the sea has gradually acquired its present quality of salt from the long-continued influx of rivers.”

Other philosophers, observing that large beds of fossil salt are not unfrequent in any quarter of the globe; and conceiving, with great probability, the bottom of the sea to be analogous in its formation to the surface of the earth, have undertaken to derive its saltness from the beds of rock salt, which they have supposed to be situated at its bottom; and they are further of opinion, that without such a permanent saline principle, the sea would long since have become insipid from the fresh water poured into it by an infinity of rivers. Strange! that what, according to the fore-mentioned hypothesis, was thought sufficient to account for the saltness of the sea, should in this be esteemed instrumental in annihilating the saltness already supposed to exist.

Boyle unites, as it were, and takes the two preceding hypotheses, and imagines the saltness of the sea to be supplied, not only from rocks and other masses of salt, which at the beginning were, and in some countries may yet be found, either at the bottom of the sea, or at the sides, where the water can reach them, but also from the salt which the rivers, rains, and other waters, dissolve in their passage through divers parts of the earth, and at length carry with them into the sea. Buffon, and the generality of philosophers, acquiesce in the opinion of Boyle.—“After all, (says he,) it may be observed, that we are inquiring into the cause of a phenomenon, which it may be said had no secondary cause at all. It is taken for granted, in this disquisition, that the water which covered the globe in its chaotic state, was not impregnated with salt as at present, but quite fresh: now this is an opinion concerning a matter of fact, which can never be proved either way; and surely we extend our speculations very far, when we attempt to explain a phenomenon, primeval to, or coeval with, the formation of the earth.”