make the heap fix or seven feet in thickness, covering it over with old mats, or any thing else, to prevent the upper leaves from be. ing blown away. In a few days the heap will come to a strong heat. For the first year or two that I used thefe leaves, I did not continue them in the heat longer than ten days or a fortnight; but in this I discovered a confiderable inconvenience, as they fettled fo much when got into the hot-houfe as foon to require a fupply. Taught by experience, I now let them remain in the heap for five or fix weeks, by which time they are properly prepared for the hothoufes. In getting them into the pine-pits, if they appear dry, we water them again, treading them in layers exceedingly well till the pits are quite full. We then cover the whole with tan to the thickness of two inches, and tread it well till the furface become fmooth and even. On this we place the pinepots in the manner they are to ftand, beginning with the middle row first, and filling up the spaces between the pots with tan. In

like manner we proceed to the next row till the whole be finished; and this operation is performed in the fame manner as when tan only is used.

After this the leaves require no farther trouble the whole feafon through, as they will retain a conftant and regular heat for twelve months without either ftirring or turning; and if I may form a judgment from their appearance when taken out, (being always entire and perfect) it is probable they would continue their heat through a fecond year; but as an annual fupply of leaves is easily obtained,

fuch a trial is hardly worth the trouble of making.

After this the pines will have no occafion to be moved but at the ftated times of their management, viz. at the shifting them in their pots, &c. when at each time a little fresh tan fhould be added to make up the deficiency arifing from the fettling of the beds; but this will be inconfiderable, as the leaves do not fettle much after their long couching. During the two first years of my practice I did not ufe any tan, but plunged the pinepots into the leaves, and just covered the furface of the beds, when finished, with a little faw-duft, to give it a neatness. This method was attended with one inconvenience;, tor by the caking of the leaves they fhrunk from the fides of the pots, whereby they became expofed to the air, and at the fame time the heat of the beds was permitted to escape.

Many powerful reafons may be given why oak leaves (for I have not tried any other kinds) are preferable to tanners bark.

First, They always heat regularly; for during the whole time that I have used them, which is near feven years, I never once knew of their heating with violence; and this is fo frequently the café with tan, that I affirm, and indeed it is well known to every person converfant in the management of the hot-house, that pines fuffer more from this one circumftance, than from all the other accidents put together, infects excepted. When this accident happens near the time of their fruiting, the effect is foon feen in the fruit, which always comes ill fhaped and exceedingly fmall. Sometimes there will

be

leaves make good manure; whereas

ten tan is experimentally found

be of no value. I have often Zeit both on fand and clay, alfo an wet and dry lands, and never A difcover, in any of my exments, that it deferved the zame of a manure; whereas decaved leaves are the richett, and ara others, the moft fuitable for a garden. But this mut only be #od of leaves after they have

ergone their fermentation, which eces them to a true vegetable mo, is which we experimentally snow that the food of plants is contained-but whether that food gea maciage, or jalt, or a comon of all three, I leave to gers to determine. This ac mould is, of all others, the mod procer to mix with compott ear, and I ufe it in general for pines, and almoft for every thing that grows in pots. For flowers it is met excellent. The remainder of this vegetable mould may be employed in manuring the quarters of the kitchen-garden, for which purpose it is highly useful.

Leaves mixed with dung make excellent hot-beds—and I find that beds compounded in this manner preserve their heat much longer than when made entirely with dung. In both cafes the application of leaves will be a confiderable faving of dung, a circumftance very agreeable, as it will be the means of preventing the contefts frequently obferved in large fami lies, between the fuperintendant of the gardens and the directors of the husbandry. Welbeck, Feb. 20, 1776.

W. SPEECHLY.

Useful

Useful Hints for learning to Swim. By Benjamin Franklin, LL.D. F. R. S. In a Letter to a Friend.

Dear Sir,

CANNOT be of opinion with you, that it is too late in life for you to learn to fwim; the river near the bottom of your garden, affords a moft convenient place for the purpose. And, as your new employment requires your being often on the water, of which you have fuch a dread, I think you would do well to make the trial; nothing being fo likely to remove thofe apprehenfions, as the confcioufness of an ability to fwim to the fhore in cafe of an accident, or of fupporting 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 fwim, having never feen much trial of them. Poffibly they may be of service in fupporting the body while you are learning what is called the ftroke, or that manner of drawing in and ftriking out the hands and feet that is neceffary to produce progreffive motion. But you will be no fwimmer till you can place fome confidence in the power of the water to fupport you; I would therefore advise the acquiring that confidence in the first place, especially as I have known feveral who, by a little of the practice neceffary for that purpofe, have infenfibly acquired the ftroke, taught as it were by na

ture.

The practice I mean is this: chufing a place where the water deepens gradually, walk coolly into it till it is up to your breaft, then turn round your face to the

fhore, and throw an egg into the water, between you and the shore; it will fink to the bottom, and be eafily feen there, as your water is clear. It muft lie in the water fo deep, as that you cannot reach it te ake it up but by diving for it. To encourage yourself in order to do this, reflect that your progress will be from deeper to fhallower 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 cpen, 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 fo easy a thing to fink as you imagined; that you cannot, but by active force, get down to the egg. Thus you feel the power of the water to fupport 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 ufed in fwimming to fupport your head higher above water, or to go forward through it.

I would the more earnestly prefs you to the trial of this method, because, though I think I fatisfied 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 ftill, and forbear ftruggling, yet, till you have ob tained this experimental confidence in the water, I cannot depend on

your

your having the neceffary prefence of mind to recollect that pofture, and the directions I gave you relating to it. The furprite may put all out of your mind. For, though we valde ourselves on being reafonable knowing creatures, reafon and knowledge feem, on fuch occafions, to be of little ufe to us: and the brutes, to whom we allow fcarce a glimmering of either, appear to have the advantage of

I will, however, take this opportunity of repeating thofe particulars to you, which I mentioned in our laft converfation, as, by perufing them at your leifure, you may poibly imprint them fo in your memory, as on occafion to be of fome use to you.

First, that, though the legs, arms, and head of a human body, being folid parts, are fpecifically fomewhat heavier than fresh water, yet the trunk, particularly the upper part, from its hollowness, is fo much lighter than water, as that the whole of the body, taken together, is too light to fink wholly under water, but fome part will remain above, until the lungs become filled with water; which happens fom drawing water into them in Sead of air, when a perfon, in the right, attempts breathing, while the mouth and noftrils are under

falt-water, and extending his arms, may easily lie fo as to keep his mouth and noftrils free for breathing; and, by a small motion of his hands, may prevent turning, if he fhould perceive any tendency to it.

4thly, That, in fresh water, if a man throws himfelf on his back, near the furface, he cannot long continue in that fituation, but by a proper action of his hands on the water. If he ufes no fuch action, the legs and lower part of the body will gradually fiok till he comes into an upright pofition, in which he will continue fufpend. ed, the hollow of the breaft keeping the head uppermott.

5thly, But if in this erect position the head is kept upright above the fhoulders, as when we ftand on the ground, the immerfion will, by

t

weight of that part of the head that is out of water, reach above the mouth and nostrils, perhaps a little above the eyes, fo that a man cannot long remain fufpended in water with his head in that pofition.

6thly, The body continued fufpended as before, and upright, if the head be leaned quite back, fo that the face looks upwards, all the back part of the head being then under water, and its weight confequently in a great measure fupported by it, the face will remain above water quite free for breathing, will rife an inch higher every infpiration, and fink as much every expiration, but never fo low as that the water may come over the mouth.

7thly, If therefore a person, unacquainted with fwimming, and falling accidentally into the water, could have prefence of mind fuffi

cient to avoid struggling and plunging, and to let the body take this natural pofition, he might continue long fafe from drowning, till perhaps help would come. For, as to the cloaths, their additional weight, while immerfed, is very inconfiderable, the water fupporting it; though, when he comes out of the water, he would find them very heavy indeed.

But, as I faid before, I would not advise you or any one to depend on having this prefence of mind on fuch an occafion, but learn fairly to swim, as I with all men were taught to do in their youth; they would, on many occurrences, be the fafer for having

that kill, and on many more the happier, as freer from painful apprehenfions of danger, to fay nothing of the enjoyment in fo delightful and wholesome an exercise. Soldiers particularly fhould, methinks, all be taught to fwim; it might be of frequent ufe either in furprizing an enemy, or faving themselves. And, if I had now boys to educate, I should prefer thofe fchools (other things being equal) where an opportunity was afforded for acquiring fo advantageous an art, which, once learnt, is never forgotten. I am, &c.

B. FRANKLIN.

ANTIQUITIES.