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candoúr and generosity, where any which you was pleased to take of part of science was the topic, a- my letter upon the late comet, did mong his select friends.
not make me more careful to obThis anecdote I thonght proper serve whatever I thought might to mention upon the present occa- tend to improve the knowledge of fion; nor can too much be said to nature, which is a capital part of his honour, among all lovers of the laudable design or the society. philosophical learning. I am Your lordship knows, that my Your lord ship's
fituation exposes me to every blast most obedient servant, that blows, and affords à fair op
James Parsons. portunity for measuring the veloP. S. The dimensions are as city of the wind (the force of which follows : viż. The length of the I am, so often, obliged to feel). I anterior horn, measuring with a have attempted to determine this Atring along the convex fore part, by letting light downy feathers fly is 20 inches; perpendicular height in the wind (the method, I under18 ; circumference 211 at the stand, used by the ingenious Dr. bafe; the posterior horn is in pera Derham); but cannot say, in all pendicular' height 191 ; circum- the trials I have made (though I ference round the base 18 ; length have let fifty of these feathers Hy, of both bases together upon the one after the other, at a time) nafal bones 14, and the weight of that I have ever seen above one, both together is 14 pounds 10 or two at most, upon which I
could have founded a calculation. The rhinoceros of the year 1739, The velocity of the wind near described in the transactions, was the earth is very unequal, upon three years old, and the horn not account of the frequent interrupthree inches high; and hence by tions it meets with from hills, trees, comparing chat with this, one may and houses; and even in open imagine this to be many years old, plains; the surface of the earth, perhaps above twenty ; and that though much smoother than it comthis animal lives to a great age.
monly is, muft reflect and interIt is also plain that the horns ropt such a fluid as the air, and are perpetual, as are those of oxen. occafion great irregularity in the
velocity of its current: this is the
reason; when a feather is let fly A letter to the president of the royal with the wind, why it feldom, if . Society, containing a new manner
ever, describes a strait line, but of measuring the velocity of wind, moves sometimes in a kind offpiral, and an experiment to ascertain to now high, and then low, fomewhat quantity of water a fall of times to the right, and then again Fnow is equal.
tớ the left ; and why two feathers
let Ay at once, seldom, if ever, Kirknewton; May' 13, 1766. keep together, or describe similar My lord,
lines. SHOULD think my self moft But, at some considerable disa
unworthy of the honour which tance from the earth, the velocity your lordship and the royal foci- of the wind seems to be regular éty have done me, if the notice and steady: nothing can be moça VoL.X
uniform than the velocity of a
that was distinct, and well defined, cloud in the sky appears to be, just touched a fouth and north line, even in the greatest storm : it is which I had marked upon the like a ship carried away insensibly ground; at that inftant I be. by a smooth and gentle current, gan my reckoning, and followed passing over equal spaces in equal the shadow with my eye in its protimes. This suggested the thought, gress, counting seconds all the that the motion of a cloud, or its while by the clock, until I had Shadow over the surface of the reckoned up 15 seconds; then I earth, would be a much more observed exactly where the afore. proper measure of the velocity of said edge of the shadow was. the wind.
This experiment I repeated ten In the end of March 1763, I times in half an hour, and seldom had as favourable an opportunity found the difference of a second, of putting this method into prac. in the time which different clouds tice, as I could have wished for: took to move over the fame space. the storm was exceeding high, and On the 5th of May current, I moved with vast velocity; the fun repeated the trial four different was bright, the sky clear, except times, the sun being also near where it was spotted with light the meridian, the wind in the Hoating clouds; I took my station' weft, with light clouds floating in in the north window of my dining a clear sky as formerly; and found room, near the clock, from which that the fhadows of different I had a free prospect of the fields ; clouds took some of them 44, and the sun was in the meridian, the others 45 seconds, to pass over the wind due west intersecting his rays same space which they had moved at right angles ; I waited until the over in 15 seconds, in the former fore-part of the shadow of a cloud, trials.
Feet This space measures exactly 1384=fpace paffed over in 15 seconds, which multiplied by
gives 5536=space passed over in one minute, which multiplied by
gives 332,160=fpace passed over in one hour. Which space is =62.9 English that the shadow took 95 seconds miles per hour, the velocity of the to pass over the above space, which wind in March 1763.
gives the velocity of the wind at One third of this (or 21 miles the rate of 9.9 English miles per nearly) fhews the velocity of the hour.. wind on May the 6th, when it . Thus, by having several lines blew a fresh gale.
in different directions of a known 'This day, May 12, there was a ' length marked upon the ground, small wefterly breeze, the velocity one may cafily (and with great acof which I measured upon the curacy, I imagine,) measure the same line, the fun being 10 mi velocity of the wind. If a person Rutes past the meridian, and found was provided with an instrument
for measuring the force of the means I took op all the snow from wind, it would perhaps be worth top to bottom in the jug; this while to observe whether, when snow I melted by the side of a fire, the velocities of different winds and the 6.2 inches of snow yielded were the same, (or nearly fo) the fix tenths of an inch deep of water forces of these winds did not vary in the same jug. After emptying with the seasons of the year, the the jug, I dried, and weighed it in points of the compass from which a balance, and took up the same the wind blows, and also with the quantity of snow in it' as before, different state of the barometer and weighed it again, and found the thermometer, since the momentum weight of the snow taken up, and of the wind depends not only from this weight computed what upon its velocity, but also upon quantity of water it ihould have its denfity.
produced, and found that it ought From the end of March 1765, to have produced fix tenths of an to the end of March last, we, in inch and one twentieth of an inch this part of Scotland, had very lit. more : then I diffolved the snow, tle rain, and less snow in propor
and found that it yielded a quan. tion; our rivers were as low, tity of water in the bottom of the through the winter, as they use to jug, fix tenths of an inch deep, be in the middle of summer; springs as in the former experiment. failed in most places, and brewers The difference of one iw ntieth and maltsters were obliged, even in of an inch in the depth of the wawinter, to carry their water at a ter, betwixt the weight and the confiderable distance; I was much melting of the snow, was probaafraid there would not be moisture bly owing to an exhalation from enough in the earth for the pur. the jug, while the snow was melt. poses of vegetation, if this reasoning by the fire, for I observed a Thould set in as dry as the former, steam sometimes rising from it. A before we got a new supply of rain. great or lesser degree of cold, or In the end of March laft, we had of wind, while the snow falls, a fall of snow; and, as I did not and its lying a longer or shorter remember to have ever read an ac. while upon the ground, will oc. count of such an experiment, I cafion a difference in the weight wished to be able to determine, to and in the quantity of water prowhat quantity of rain this fall of duced from a certain number of snow was equal.
cubic feet, or inches, of snow ; The snow had been falling from but, if I may trust to the above five o'clock the former evening, trials, (which I endeavoured to till ten o'clock the next day; about perform with care) snow, newly cleven o'clock I meafured the depth fallen, with a moderate gale of of the snow, and found it to be 6.2 wind, freezing cold, which was inches ; then I took a stone jug, the case of the snow I made the holding about three English pints, trials upon, the 27th of March laft, and turned the mouth of it down- will produce a quantity of water wards upon the snow measured, equal to one tenth part of its and where the ground below was bulk; or the earth, when covered smooth and hard ; and by this with snow, ten inches deep, will be moistened by it when melted, people, have left a vast chain of rivers and springs recruited, as country, of about 300 miles in much as if a quantity of rain had breadth, and of a prodigious fallen that covered the surface of length, waste and uninhabited, as the earth to the depth of one a common barrier between them. inch,
This country, which is one of the I am, my lord, &c. fineft in Ala, produces the best Alex. Brice. rhubarb in the world, and runs the
whole length of Mongalia, divid.
ing it into two parts. We shall Some curious particulars relative to now give our curious traveller's
the growth of rhubarb; how an own words. animal called the marmot contri. The country retained much the butes to its propagation, and how same appearance, and the weather the natives dry ihe root. Taken was very fine : but not a hngle from Mr. Beil's travels,
inhabitant was yet to be seen. In
the evening I walked from our HE best rhubarb grows in tents, with some of our company, T of Tartary called Mongalia, a vast where I found many plants of ex. country inhabited by the Mongall cellent rhubarb; and, by the help Tartars, and which now serves as of a stick, dug up as much of it as a boundary between the two migh. I wanted. ty empires of Russia and China. On these hills are a great num. The Mongalls, though once a great ber of animals called marmots, of and independent people, have not. a brownish colour, having feet like withstanding by degrees been in- a badger, and nearly of the same duced to put themselves under the size. They make deep burrows protection of one or other or these on the declivities of the hills; their powerful neighbours. This and, it is said, that, in winter, measure seems rather to have pro. they continue in thefe holes, for a ceeded from the love of ease, a de certain time, even without food. fire of security, and a want of una. At this season, however, they fit nimity; than to have been the ef- or lie near their burrows, keeping fect of fear, 'or the consequence of a strict watch ; and, at the ap. an absolute conquest. The Mon. proach of danger, rear themselves gallians still fetain their own laws, upon their hind-feet, giving a loud cuftoms, and princes; and though whistle, like a man, to call in the they submit to certain regulations, ftragglers; and then drop into it does not appear that they pay their holes in a moment, any tribute. This submission has I should not have mentioned however divided their country and an animal so well known as the nation into what may be called marmot, had it not been on ac. Russian and Chinese ; the two count of the rhubarb. Wherc. great, jealous neighbours, to pre. ever you see ten or twenty plants vent the continual disputes which growing, you are fure of finding would have happened about li. several burrows under the shades mits, or the defertion of their of their broad spreading leaves. Perhaps they may sometimes eat expence, that much diminish the the leaves and roots of this plant : profits on this commodity. At however, it is probable, the ma- present, the dealers in this article nure they leave about the roots, think these improvements not worcontributes not a little to its in- thy of their attention, as their crease; and their casting up the gains are more considerable on carth, makes it shoot out young this than on any other branch of buds, and multiply. This plant trade. Perhaps the government does not run, and spread itself, may hereafter think it proper to like docks, and others of the same make some regulations with regard species; but grows in cufts at to this matter, uncertain distances, as if the seeds I have been more particular in had been dropped with design. describing the growth and manageIt appears that the Mongalls ne- ment of the rhubarb ; because I ver accounted it worth cultivat. never met with an author, or pering; but that the world is o. fon, who could give a satisfactory bliged to the marmots for the account where, or how, it grows. quantities scattered, at random, I am persuaded, that in such a in many parts of this country ; dry climate as this, it might for whatever part of the ripe feed easily be fo cultivated as to proq happens to be blown among the duce any quantity that could be thick grass, can very seldom reach wanted. the ground, but must there wither and die; whereas, should it fall among the loose earth, thrown up Some account of the horns, called by the marmots, it immediately mammon's horns, and the Arange takes root, and produces a new opinions the Tartars hold of the plant.
kind of animal to which they After digging and gathering the imagine they belonged. From the rhubarb, the Mongalls cut the
fame. large roots into small pieces, in order to make them dry more readily. In the middle of every piece N the banks of the Oby, about
are found great they scoop a hole, through which quantities of that kind of ivory a cord is drawn, in order to fus. called, in this country, mammon's pend them in any convenient horn. Some of it also is found place. They hang them for most the banks of the Volga. part about their tents, and some. Mammon's horn, resembles, in times on the horns of their sheep. shape and fize, the teeth of a This is a moft pernicious cuftom, large elephant. The vulgar really as it destroys some of the best part imagine mammon to be a creature of the root'; for all about the hole living, in marshes and under is rotten and useless; whereas, ground; and entertain, many were people rightly informed how it range notions concerning it. to dig and dry this plant, there The Tartars tell many fables of would not be one pound of re. its having been seen alive. But fuse in an hundred ; which would to me it appears that this horn is save a great deal of trouble and the tooth® of a large elephant.