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Septem.

568290

A Journal of a Voyage from the Channel between France and England towards America.

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N. B. Longitude is reckoned from London, and the thermometer is according to Fahrenheit.

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July 31. At one P. M. the Start bore W N W. distant six leagues.

August 1. The water appears luminous in the ship's wake.

2. The temperature of the water is taken at eight in the morning and at eight in the evening. 6. The water appears less luminous. 7. Formegas SW. dist. 32 deg. St. Mary's SWIS. 33 leagues.

8. From this date the temperature of the water is taking at eight in the morning and at six in the evening.

August 10. Moonlight, which prevents the luminous appearance of the water.

11. A strong southerly current.

- 12. Ditto. From this date the temperature of the air and water was taken at noon, as well as morning and evening.

16. Northerly current.

19. First saw gulph weed.
21. Southerly current.
22. Again saw gulph weed.

24. The water appeared luminous in a small

degree before the moon rose.

August 29. No moon, yet very little light in tion that by the valves being both open when

the water.

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- 30. Much gulph weed to-day.

- 31. Ditto.

September 1. Ditto.

2. A little more light in the water.

going down, and both shut when coming up, it would keep within it the water received at bottom. The upper valve performed its office well, but the under one did not shut quite close, so that much of the water was lost in hauling it up the ship's

- 4. No gulph weed to-day. More light in side. As the water in the keg's passage upwards

the water.

-5. Some gulph weed again.

could not enter at the top, it was concluded that what water remained in it was of that near the

6. Little light in the water. A very hard ground, and on trying this by the thermometer, it thunder-gust in the night. was found to be at 58, which was twelve degrees colder than at the surface.

-7. Little gulph weed.

8. More light in the water. Little gulph weed.

9. Little gulph weed. Little light in the water last evening.

10. Saw some beds of rock-weed; and we were surprised to observe the water six degrees colder by the thermometer than the preceding noon. This day (10th) the thermometer still kept descending, and at five in the morning of the 11th, it was in water as low as 70, when we struck soundings. The same evening the pilot came on board, and we found our ship about five degrees of longitude ahead of the reckoning, which our captain accounted for by supposing our course to have been near the edge of the gulph stream, and thus an eddy current always in our favour. By the distance we ran from Sept. 9, in the evening, till we struck soundings, we must have been at the western edge of the gulph stream, and the change in the temperature of the water was probably owing to our suddenly passing from that current, into the waters of our own climate.

On the 14th of August the following experiment was made. The weather being perfectly calm, an empty bottle, corked very tight, was sent down twenty fathoms, and it was drawn up still empty. It was then sent down thirty-five fathoms, when the weight of the water having forced in the cork, it was drawn up full; the water it contained was immediately tried by the thermometer, and found to be 70, which was six degrees colder than at the surface: the lead and bottle were visible, but not very distinctly so, at the depth of twelve fathoms, but when only seven fathoms deep they were perfectly seen from the ship. This experiment was thus repeated Sept. 11, when we were in soundings of eighteen fathoms. A keg was previously prepared with a valve at each end, one opening inward, the other outward; this was sent to the bottom in expecta

This last Journal was obligingly kept for me by Mr. J. Williams, my fellow-passenger in the London Packet, who made all the experiments with great exactness. [The late colonel Williams of the U. S. Engineers.]

The chart in this edition, was constructed with a

view to a more comprehensive idea of the course of the gul h stream. Volney suggests, that the earth depositeu by the gulph stream S. E. of Newfoundland, has formed the great banks; and that the accumulation there, has given the stream a new or more eastwardly direction. The chart also serves to illustrate the long received ideas of the progress of the shoals of fish. May not the glutinous matter seen on the water, and which all persons who have been across the line must have noticed to be luminous at night, be another cause of the phenomena of fish shoals. May they not come in search of the food, which the matter seen on the water in such abundance affords? The writer of this note has observed, that on entering the trade winds, the seamen have judged of the change of wind ap proaching, by the direction of the bonetta and other fish, which pass in shoals in the South Atlantic and South-eastern seas, in a direct opposition to the wind; and when not opposite to the prevailing wind, they conclude a change to be at hand from the direction towards which the fish go. The appearance of luminous floating matter at night is often followed by shoals of fish; the spawn or gluten, which the writer has had taken up in a bucket, has been often found as large as two inches diameter, and frequently induced an opinion that it was a species of maritime cocoon or egg of an animal. An inquiry into the periodical appearance of these luminous substances on voyages to the southward, and remarks on the usual direction of the shoals of bonetta and other fish, might perhaps lead to interesting discoveries; it might be assumed as a question worthy of examination, whether the direction of shoals of fish is not towards those points from which periodical winds or currents move the waters; and that the shoals of fish which move from the north poles, by the British isles across the Atlantic, are led by their instincts in search of these periodical supplies of food; and if the deposits so made by the gulph stream on the banks of Newfoundland is not the true cause of the great abundance of fish found there.

W. D.

To Oliver Neale.

On the Art of Swimming.

I CANNOT be of opinion with you that it is too late in life for you to learn to swim. The river near the bottom of your garden affords a most convenient place for the purpose. And as your new employment requires your being often on the water, of which you have such a dread, I think you would do well to make the trial; nothing being so likely to remove those apprehensions as the consciousness of an ability to swim to the shore, in case of an accident, or of supporting yourself in the water till a boat could come to take you up.

I do not know how far corks or bladders may be useful in learning to swim, having never seen much trial of them. Possibly they may be of service in supporting the body while you are learning what is called the stroke, or that manner of drawing in and striking out the hands and feet that is necessary to produce progressive motion. But you will be no swimmer till you can place some confidence in the power of the water to support you; I would therefore advise the acquiring that confidence in the first place; especially as I have known several who, by a little of the practice necessary for that purpose, have insensibly acquired the stroke, taught as it were by nature.

The practice I mean is this. Choosing a place where the water deepens gradually, walk coolly into it till it is up to your breast, then turn round, your face to the shore, and throw an egg into the water between you and the shore. It will sink to the bottom, and be easily seen there, as your water is clear. It must lie in water so deep as that you cannot reach it to take it up but by diving for it. To encourage yourself in order to do this, reflect that your progress will be from deeper to shallower water, and that at any time you may, by bringing your legs under you, and standing on the bottom, raise your head far above the water. Then plunge under it with your eyes open, throwing yourself towards the egg, and endeavouring by the action of your hands and feet against the water to get forward till within reach of it. In this attempt you will find, that the water buoys you up against your inclination; that it is not so easy a thing to sink as you imagined; that you cannot but by active force get down to the egg. Thus you feel the power of the water to support you, and learn to confide in that power; while your endeavours to overcome it, and to reach the egg, teach you the manner of acting on the water with your feet and hands, which action is afterwards used in swimming to support your head higher above water, or to go forward through it.

I would the more earnestly press you to the trial of this method, because, though I think

I

satisfied you that your body is lighter than water, and that you might float in it a long time with your mouth free for breathing, if you would put yourself in a proper posture, and would be still and forbear struggling; yet till you have obtained this experimental confidence in the water, I cannot depend on your having the necessary presence of mind to recollect that posture and directions I gave you relating to it. The surprise may put all out of your mind. For though we value ourselves on being reasonable knowing creatures, reason and knowledge seem on such occasions to be of little use to us; and the brutes to whom we allow scarce a glimmering of either, appear to have the advantage of us.

I will, however, take this opportunity of repeating those particulars to you, which I mentioned in our last conversation, as, by perusing them at your leisure, you may possibly imprint them so in your memory as on occasion to be of some use to you.

1. That though the legs, arms, and head of a human body, being solid parts, are specifically something heavier than fresh water, yet the trunk, particularly the upper part, from its hollowness, is so much lighter than water, as that the whole of the body taken together is too light to sink wholly under water, but some part will remain above, until the lungs become filled with water, which happens from drawing water into them instead of air, when a person in the fright attempts breathing while the mouth and nostrils are under water.

2. That the legs and arms are specifically lighter than salt water, and will be supported by it, so that a human body would not sink in salt water, though the lungs were filled as above, but from the greater specific gravity of the head.

3. That therefore a person throwing himself on his back in salt water, and extending his arms, may easily lie so as to keep his mouth and nostrils free for breathing; and by a small motion of his hands may prevent turning, if he should perceive any tendency to it.

4. That in fresh water, if a man throws himself on his back, near the surface, he cannot long continue in that situation but by proper action of his hands on the water. If he uses no such action, the legs and lower part of the body will gradually sink till he comes into an upright position, in which he will continue suspended, the hollow of the breast keeping the head uppermost.

5. But if, in this erect position, the head is kept upright above the shoulders, as when we stand on the ground, the immersion will, by the weight of that part of the head that is out of water, reach above the mouth and nostrils, perhaps a little above the eyes, so that a man cannot long remain suspended in water with his head in that position.

6. The body continuing suspended as be

fore, and upright, if the head be leaned quite I pushed the edges of these forward, and 1 back, so that the face looks upwards, all the back part of the head being then under water, and its weight consequently in a great measure supported by it, the face will remain above water quite free for breathing, will rise an inch higher every inspiration, and sink as much every expiration, but never so low that the water may come over the mouth.

7. If therefore a person unacquainted with swimming and falling accidentally into the water, could have presence of mind sufficient to avoid struggling and plunging, and to let the body take this natural position, he might continne long safe from drowning till perhaps help would come. For as to the clothes, their additional weight while immersed is very inconsiderable, the water supporting it, though, when he comes out of the water, he would find them very heavy indeed.

But, as I said before, I would not advise you or any one to depend on having this presence of mind on such an occasion, but learn fairly to swim; as I wish all men were taught to do in their youth; they would, on many occurrences, be the safer for having that skill, and on many more the happier, as freer from painful apprehensions of danger, to say nothing of the enjoyment in so delightful and wholesome an exercise. Soldiers particularly should, methinks, all be taught to swim; it might be of frequent use either in surprising an enemy, or saving themselves. And if I had now boys to educate, I should prefer those schools (other things being equal) where an opportunity was afforded for acquiring so advantageous an art, which once learned is never forgotten. B. FRANKLIN.

On the same subject, in answer to some quiries of M. Dubourg.*

struck the water with their flat surfaces as I drew them back. I remember I swam faster by means of these pallets, but they fatigued my wrists. I also fitted to the soles of my feet a kind of sandals; but I was not satisfied with them, because I observed that the stroke is partly given by the inside of the feet and the ancles, and not entirely with the soles of the feet.

We have here waistcoats for swimming, which are made of double sail-cloth, with small pieces of cork quilted in between them.

I know nothing of the scaphandre of M. de la Chapelle.

I know by experience, that it is a great comfort to a swimmer, who has a considerable distance to go, to turn himself sometimes on his back, and to vary in other respects the means of procuring a progressive motion.

When he is seized with the cramp in the leg, the method of driving it away is to give to the parts affected a sudden, vigorous and violent shock; which he may do in the air as he swims on his back.

During the great heats of summer there is no danger in bathing, however warm we may be, in rivers which have been thoroughly warmed by the sun. But to throw oneself into cold spring water, when the body has been heated by exercise in the sun, is an imprudence which may prove fatal. I once knew an instance of four young men, who, having worked at harvest in the heat of the day, with a view of refreshing themselves, plunged into a spring of cold water: two died upon the spot, a third the next morning, and the fourth recovered with great difficulty. A copious draught of cold water, in similar circumstances, is frequently attended with the same In-effect in North America.

The exercise of swimming is one of the most healthy and agreeable in the world. After -I AM apprehensive that I shall not be having swam for an hour or two in the evenable to find leisure for making all the disqui-ing, one sleeps coolly the whole night, even sitions and experiments which would be desirable on this subject. I must, therefore, content myself with a few remarks.

The specific gravity of some human bodies, in comparison to that of water, has been examined by Mr. Robinson, in the Philosophical Transactions, volume 50, page 30, for the year 1757. He asserts, that fat persons with small bones float most easily upon the water. The diving-bell is accurately described in the Transactions.

When I was a boy, I made two oval pallets, each about ten inches long, and six broad, with a hole for the thumb, in order to retain it fast in the palm of my hand. They much resembled a painter's pallets. In swimming

*This and the four following extracts of letters to M. Dubourg, are retranslated from the French edition of Dr. Franklin's works.

during the most ardent heat of summer. Per-
haps the pores being cleansed, the insensible
perspiration increases and occasions this cool-
ness. It is certain that much swimming is
the means of stopping a diarrhoea, and even of
producing a constipation. With respect to
those who do not know how to swim, or who
are affected with a diarrhoea at a season which
does not permit them to use that exercise, a
warm bath, by cleansing and purifying the
radical cure.
skin, is found very salutary, and often effects a
I speak from my own expe-
rience, frequently repeated, and that of others
to whom I have recommended this.

You will not be displeased if I conclude these hasty remarks by informing you, that as to the act of rowing with the arms and legs, the ordinary method of swimming is reduced and is consequently a laborious and fatiguing

operation when the space of water to be crossed is considerable; there is a method in which a swimmer may pass to great distances with much facility, by means of a sail. This discovery I fortunately made by accident, and in the following manner.

whatever resulting from it, and that at least
it does not injure my health, if it does not in
fact contribute much to its preservation. I
shall therefore call it for the future a bracing
or tonic bath.
B. FRANKLIN.

On the Causes of Colds.

March 10, 1773.

When I was a boy I amused myself one day with flying a paper kite; and approaching the bank of a pond, which was near a mile broad, I tied the string to a stake, and the -I SHALL not attempt to explain why kite ascended to a very considerable height damp clothes occasion colds, rather than wet above the pond, while I was swimming. In a ones, because I doubt the fact; I imagine that little time, being desirous of amusing myself neither the one nor the other contribute to with my kite, and enjoying at the same time this effect, and that the causes of colds are the pleasure of swimming, I returned; and totally independent of wet and even of cold. loosing from the stake the string with the lit- I propose writing a short paper on this subtle stick which was fastened to it, went again ject, the first moment of leisure I have at my into the water, where I found, that, lying on disposal. In the meantime I can only say, my back and holding the stick in my hands, I that having some suspicions that the common was drawn along the surface of the water in a notion, which attributes to cold the property very agreeable manner. Having then engaged of stopping the pores and obstructing perspianother boy to carry my clothes round the pond, ration, was ill-founded, I engaged a young to a place which I pointed out to him on the physician, who is making some experiments other side, I began to cross the pond with my with Sanctorius's balance, to estimate the difkite, which carried me quite over without the ferent proportions of his perspiration, when least fatigue, and with the greatest pleasure remaining one hour quite naked, and another imaginable. I was only obliged occasionally warmly clothed. He pursued the experiment to halt a little in my course, and resist its pro- in this alternate manner for eight hours sucgress, when it appeared that, by following too cessively, and found his perspiration almost quick, I lowered the kite too much; by doing double during those hours in which he was which occasionally I made it rise again. I naked. E have never since that time practised this singular mode of swimming, though I think it not impossible to cross in this manner from Dovery to Calais. The packet-boat, however, is still preferable. B. FRANKLIN.

To M. Dubourg.

On the free Use of Air.

B. FRANKLIN.

To Francis Hopkinson.
On the Vis Inertia of Matter.

PHILADELPHIA, 1748.

ACCORDING to my promise, I send you in writing my observations on your book ;* you will be the better able to consider them; which I desire you to do at your leisure, and set me right where I am wrong.

I stumble at the threshold of the building, and therefore have not read farther. The author's vis inertia essential to matter, upon which the whole work is founded, I have not been able to comprehend. And I do not think he demonstrates at all clearly (at least to me he does not) that there is really such a pro

LONDON, July 28, 1760. GREATLY approve the epithet which you give, in your letter of the 8th of June, to the new method of treating the small-pox, which you call the tonic or bracing method; I will take occasion, from it, to mention a practice to which I have accustomed myself. You know the cold bath has long been in vogue here as a tonic; but the shock of the cold water perty in matter. has always appeared to me, generally speak of matter be called a, and let any given ceHe says, No. 2. "Let a given body or mass ing, as too violent, and I have found it much That celerity doubled, more agreeable to my constitution to bathe in lerity be called c. another element, I mean cold air. With this tripled, &c. or halved, thirded, &c. will be 2 view I rise almost every morning, and sit in C, 3 c, &c. or c, c, &c. respectively; also the body doubled tripled, or halved, thirded, my chamber without any clothes whatever, half an hour or an hour, according to the sea-Thus far is clear. But he adds, "Now to will be 2 a, 3 a, ora, a, respectively." son, either reading or writing. This practice is not in the least painful, but, on the contrary, agreeable; and if I return to bed afterwards, before I dress myself, as sometimes happens, I make a supplement to my night's rest of one or two hours of the most pleasing sleep that can be imagined. I find no ill consequences

a certain force to be impressed upon it; and to move the body a with the celerity c, requires that force to be impressed upon it, &c.” Here move it with a celerity as 2 c, requires twice

* Baxter's Inquiry into the Nature of the Human

Soul.

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