« ZurückWeiter »
thrust away, were not proper for its food. From this discovery we may conclude, that since this kind of animalculum cannot move from place to place in the water, nor consequently pursue its food, as other creatures do, that are endued with motion, being fastened by the tail or other parts of the body, it must necessarily be provided with such instruments as are fit to move the water, and by that means come at the particles floating in it, which serve for the nourishment, increase, and defence of its body.
I likewise observed a very few animalcula, whose bodies were short and thick, and much larger than those other animalcula that lodged themselves in a sheati., and were fastened by their tail, or extreme parts, to the little roots of the duckweed;
and though these short and thick animalcula could move from place to place, yet they also had a circular motion in the fore part of their bodies. From whence I concluded, that those motions served some other purposes than only to draw their food to them. On further considering what could be the use of these indented wheel-works, which are so like the indented wheels of a clock, or watch, I must own that they are very necessary to produce a great motion in the water; for, were it a round and smooth wheel, it would cause but a very small motion; whereas now, each tooth in the said wheel or circle produces a great motion, in comparison of what a smooth and plain wheel would do. Whence appears the surprising order in the formation of such small creatures, which are not to be perceived by the naked eye.
Concerning the Luminous Appearance observable in the Wake of Ships in the Indian Seas, &c. By FATHER BOURZES,
WHEN the ship ran apace, we often observed a great light in the wake, or the water that is broken and divided by the ship in its passage.
This light was not always equal : some days it was very little, others not at all; sometimes brighter, at others fainter; sometimes it was very vivid, and at other times nothing was to be seen. As to its brightness, I could easily read by it, though I was nine or ten feet above it from the surface of the water ; that is, the title of my book, which was in large letters.
Not only the wake of a ship produces this light, but fishes also in swimming leave behind them a luminous track; which is so bright, that one may distinguish the size of the fish, and know of what species it is. I have sometimes seen a great many fishes playing in the sea, which have made a kind of artificial fire in the water, that was a very pleasant sight. And often only a rope, placed crosswise, will so break the water, that it will become luminous. If one take some water out of the sea, and stir it ever so little with his hand in the dark, he may see in it an infinite number of bright particles. Or if one dip a piece of linen in sea-water, and twist or wring it in a dark place, he will see the same thing, and if it be even half dry.
The production of this light depends very much on the quality of the water ; and, if I am not deceived, generally speaking, I may assert, other circumstances being equal
, that the light is largest when the water is fattest and fullest of foam ; for in the main' sea the water is not every where equally pure ; and sometimes linen dipped into the sea is clammy when it is drawn up again. And I have often observed, that when the wake of the ship was brightest, the water was more fat and glutinous ; and linen moistened with it produced a great deal of light, if it were stirred or moved briskly.
Besides, in sailing over some places of the sea, we find a matter or substance of different colours, sometimes red, sometimes yellow. In looking at it, one would think it sawdust; our sailors say it is the spawn or seed of whales. What it is, is not certain ; but when we draw up water in passing over these places, it is always viscous and glutinous. Our mariners also say, that there are a great many heaps or banks of this spawn in the north ; and that sometimes in the night they appear all over of a bright light, without being put in motion by any vessel or fish passing by them.
But to confirm further what I say, viz. that the water, the more glutinous it is, the more it is disposed to become luminous, I shall add one particular which I saw myself. One day we took in our ship a fish, which some thought was a boneta. The inside of the mouth of the fish appeared in the night like a burning coal ; so that without any other light I could read by it the same characters that I read by the light in the wake of the ship. Its mouth being full of a viscous humour, we rubbed a piece of wood with it, which immediately became all over luminous; but as soon as the moisture was dried up, the light was extinguished.
An Account of a Woman who had lain six Days covered with
Snow, without receiving any Nourishment, &c. By Mr. SAMUEL BOWDICH. - [1713.]
JOANNA Crippen, of Chardstock, in Dorset, being a spinner of worsted, was going home on the 24th of January with some work, but snow falling abundantly, and lying deep on the ground, she was forced to lie down under a hedge, having lost one of her shoes ; and her clothes, which were very mean, were by the brambles and thorns torn almost off her back : in which place she lay from Monday evening about six o'clock, until Sunday following about four in the afternoon, and then was discovered by some of our neighbours, who went out with poles, shovels, &c. to search for her; and after some time spent in it, at last found her buried in four feet deep of snow. One of the men thrusting at her with his pole, found she was there, and alive. She immediately spoke, and begged he would not push her too hard, for she was almost naked ; and desired that some of the women would come to her, and take her out, which was accordingly done; when they found her without stockings or shoes, an old whittle about her shoulders, with a large hole in it, which she had ate through : the snow melting down on her, she drank to quench her thirst. She had a mortification of one of her great toes, but she now is very hearty, and in a fair way of a perfect recovery. She was very sensible at the first taking her out, and still continued so ; and she knew every body perfectly well : and yet she had taken no manner of food all the time of her being in the snow.
An Account of several extraordinary Meteors or Lights in the
Sky. By Dr. EDMUND HALLEY. - [1714.] The theory of the air seems now to be perfectly well understood, and its different densities at all altitudes, both by reason and experiment, are sufficiently defined; for, supposing the same air to occupy spaces reciprocally proportional to the quantity of the superior or incumbent air, I have else where proved, that at 40 miles high the air is rarer than at the surface of the earth about 3000 times; and that the utmost height of the atmosphere, which reflects light in the crepusculum, is not fully 45 miles.
That meteor which was seen in 1708, on the 31st of July, between 9 and 10 o'clock at night, was evidently between 40 and 50 miles perpendicularly high, and as near as I can gather, over Sheerness and the buoy on the Nore. It appeared to move with an amazing velocity, darting, in a very few seconds of time, for about twelve degrees of a great circle from north to south, being very bright at its first appearance, and it died away at the end of its course, leaving for some time a pale whiteness in the place, with some remains of it in the track where it had gone; but no hissing sound, as it passed, or explosion were heard.
Like to this, but much more considerable, was that famous meteor which was seen to pass over Italy on the 21st of March O.S. anno 1676, about an hour and three quarters after sunset, which happened to be observed, and was well considered, by the famous professor of mathematics in Bononia, Geminian Montanari, as may be seen in his Italian treatise about it, soon after published at Bononia. He oba serves that at Bononia its greatest altitude in the S.S.E. was 38 degrees, and at Sienna 58 to the N.N.W.: that its course, by the concurrence of all the observers, was from E.N.E. to W.S.W.: that it came over the Adriatic Sea as from Dalmatia: that it crossed over all Italy, being nearly vertical to Rimini and Savigniano on the one side, and to Leghorn on the other : that its perpendicular altitude was at least 38 miles: that in all places near this course, it was heard to make a hissing noise as it passed, like that of artificial fire-works : that having passed over Leghorn, it went off to sea towards Corsica ; and, lastly, that at Leghorn it was heard to give a very loud report like a great cannon; immediately after which, another sort of sound was heard, like the rattling of a great cart running over stones. He concludes, from the apparent velocity it went with at Bononia, at above 50 miles distance, that it could not be less swift than 160 miles in a minute of time, which is above ten times as swift as the diurnal rotation of the earth under the equinoctial, and not many times less than that with which the annual motion of the earth about the sun is performed. To this he adds its magnitude, which appeared at Bononia larger than the moon in one diameter, and above half as large again in the other; which, with the given distance of the eye, makes its real less diameter above half a mile, and the other in proportion. This supposed, it cannot be wondered that so great a body moving wit amazing velocity through the air, though so much rarefied as it is in its upper regions, should occasion so loud a hissing noise, as to be heard at such a distance as it seems this was.
I have much considered this appearance, and think it one of the hardest things to account for that I have yet met with
in the phenomena of meteors, and am induced to think that it must be some collection of matter formed in the ether, as it were by some fortuitous concourse of atoms, and that the earth met with it as it passed along in its orb. For its direction was exactly opposite to that of the earth, which made an angle with the meridian at that time (the sun being in about 11 degrees of Aries) of 67°, that is, its course was from W.S.W. to E.N.E., so that the meteor seemed to move the contrary way. And besides, falling into the power of the earth's gravity, and losing its motion from the opposition of the medium, it seems that it descended towards the earth, and was extinguished in the Tyrrhene Sea, to the W. S.W. of Leghorn. The great report being heard on its first immersion into the water, and the rattling, like the driving a cart over stones, being what succeeded on its quenching ; something like which is always observed on quenching a very hot iron in water.
On his own Philosophy. By Sir Isaac Newton.— [1714.]
The philosophy which Mr. Newton, in his Principles and Optics, has pursued, is experimental; and it is not the bus siness of experimental philosophy to teach the causes of things, any further than they can be proved by experiments. We are not to fill this philosophy with opinions which cannot be proved by phenomena. In this philosophy, hypotheses have no place, unless as conjectures or questions proposed to be examined by experiments. For this reason, Mr. Newton in his Optics distinguished those things which were made certain by experiments, from those things which remained uncertain, and which he therefore proposed in the end of his Optics in the form of queries. For this reason, in the preface to his Principles, when he had mentioned the motions of the planets, comets, moon, and sea, as deduced in this book from gravity, he added, “ I wish the other phenomena of nature could by the same way of reasoning be deduced from mechanical prin ciples; for several things induce me to believe, that all these things may depend upon certain forces, by which the particles of bodies are, by causes still unknown to us, either mutually impelled towards each other, and cohere together according to certain regular configurations, or mutually recede from each other; and for want of knowing these forces philosophers have hitherto attempted to no purpose to explain nature." And in the end of this book, in the second edition, he said, that for want of a sufficient number of experiments, he forbore