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The Philosophical transactions of the Royal society of London, from their commencement in 1665, in the year 1800 (Volume 8) online

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length and breadth, if it rains in that particular field, yet it may be fair in the
next adjoining : and if in harvest, or on a journey, you proclaim it will rain on
the morrow, some will, if it does not fall on their land, or on their coat, be so
silly as to say the prediction was false.

1. The barometer only shows the pressure or weight of the atmosphere, and
inclination of the air, in and about the country where it stands, and not always
in a particular spot : so that in foretelling of great rains, people are apt to say
the indication is false, because they have not seen or heard of it; when perhaps
in a day or two you will hear, that it did then fall 3, 4, or perhaps 10 miles off.
p'or though the rain should be over us when the glass fell, yet the wind, which
bloweth where it listeth, cjirries the clouds and rain with it.

3. It is very hard to distinguish on the mercury's falling, whether it will be
rain or high winds, these equally causing the mercury to subside.

4. Of all those who guess at the weather from the whims of their own brains,
it is observable, it is not true one time in ten, nor do any two of them agree
about it. But from observations on this barometer, it will seldom fail you once
in 20 ; so that it is above 100 to 1 preferable.

5. If from the state of the mercury yesterday and this morning, it be pro-
nounced the next day will be no rain, and we look, at the glass no more to-day;
perhaps winds may arise, and so alter the atmosphere's weight, and the glass
falls much, it will rain on the morrow, contrary to what was at first expected.
Here it is plain, had the glass been seen again in the afternoon, the rain might
have also been foreseen.

Hence it is evident from these remarks, that judgments are taken on the
weather from barometers, which do not prove so; and this produces opinions in
the vulgar and ignorant, that there is no judgment at all to be had from them.

If the barometer could only foretel very great and remarkable changes of the
weather ; for instance, in harvest-time, that a very great rain, or perhaps
floods, were coming ; the husbandman would stop cutting down his grain, and
save some of it being spoiled by the wet : or on a journey, if I know that if I


do not get home bj- such a time, or pass such rivers, the floods will be so great,
as not only to prevent me, but endanger my life : and perhaps here is a man's
fortune saved, nay his life, merely from the indications of the barometer ; and
he who reckons this nothing, deserves neither.

The greatest storm that has been in our days, was Jan. 8, 1734-5. On the
5th the mercury began to fall, and on the 8th was a 10th below 28 inches;
which has not been seen in this age, or perhaps since Torricelli's time ; thence
I could plainly indicate, that it would be the greatest flood we ever heard of, or
the greatest storm we ever felt ; the latter of which it proved.

Some Rules and Observations for fore-knowing the Weather, by the rising a7id
falling of the Mercury. — Though rising always presages fair, and falling foul
weather, yet there are several difficulties and niceties in making a true judg-
ment from them, and herein consists the chief part of the art.

We need not recount the several observations made by Dr. Halley, Dr. Beal,
Dr. Derham, Mr. Patrick, and others, though they are most of them appli-
cable to this improved diagonal barometer, as they are in so many hands, and
in most authors on the subject, and because Mr. B. has collected them, in
order to be made public, at the request of the improver of the barometer, Mr.
Orme, and for his use; which ^me time since were put into the hands of Dr.
Desaguliers, who is acquainted with Mr. Orme and his glasses. Mr. B. only
inserts here some few observations, which may be called rules, as he has
deduced them from time to time, in using Mr. Qrme's glasses, and keeping a
register of the weather.

Rules and observations for the improved diagonal barometer. — 1. This baro-
meter very rarely foretels thunder, seldom falling at all before it, which Mr.
Patrick observes others do.

2. In serene and hot weather, when the mercury is high and rising, and you
have all the possible certainty of fair weather the next day, and if there happen
to fall great showers, you may conclude they have been driven on you by
thunder, though you have heard nothing of it.

' 3. When the mercury is pretty high, and has fallen to foretel rain, and it
rises again before the rain comes; it indicates there will be but little of it.

4. If the mercury continues falling while it rains, it shows it will rain the
next day.

5. In fair weather, when the mercury has continued high or rising, if it falls
a little to-day about noon, and towards the evening rises again, you must expect
a single shower the latter part of the next day, or perhaps by noon, and then
fair weather again forward.

■ '6. When the mercury rises gradually, about half a 10th perpendicular, and



continues so to do for many days together; you may reasonably expect a fair
season for as long a time as it was rising, unless some gales of wind intervene,
and especially the s. w. by s. or thereabouts.

7. When the mercury rises very fast, or falls very fast, neither the fair nor
foul weather it forebodes will continue long.

8. Without knowing how the mercury has stood some little time before, a
true judgment cannot be given at all times; for suppose we find it in a rising
condition, it will probably be fair; but if it had been higher some hours ago,
and fell, there must happen a shower.

Why the mercury in the diagonal barometer, if it be for fair weather, on
tapping the case several times, which jars and makes the tube tremble, will rise
at every stroke for several strokes together, and in all sometimes a 10th of an
inch, or more, in the perpendicular; may be thus accounted for:

1. There is a cohesion of the mercury to the tube, which hinders its rising,
and such tapping releases that.

2. But it is observable, that it will rise a little at all times, even when it is in
a standing, or even in a falling condition. This may be accounted for thus:

The mercury and atmosphere are in an equilibrio, and tapping starts and
raises the mercury a little in a boiling manner, especially its upper surface,
which is seen to leap, or be in a swimming posture; then the pressure of the
atmosphere over-balances the remainder of the mercury, and it must rise a

Or such violent jarring puts the mercury in a lateral and upward motion, for
downward it cannot go, which takes off its gravity, as the winds lessen the
pressure of the air; therefore it must rise a little.

But then it is observable also, that if the mercury was in a standing condi-
tion, or falling, such rising as above, will in a minute return to the same place
again ; and even when the mercury is in a rising condition, it will, in that
space of time, fall a little part of that it rose by such tapping.

This barometer has the coruscations, as they were observed in Mr. Patrick's
pendant one; for by tapping the case with the finger in a dark place, it will emit
several bright flashes, along the empty part of the tube. This is an argument
that the vacuum is very pure, and the mercury truly purged.

Collections from the diary of the weather and barometer, in order to settle rules
for foretelling the weather by the barometer.

Great Storms. 6. . . . night 29.2

Before them the mercury falls 3 or 4 days, and T. ...night 28.1

» exceedingly low. 8 noon 27.9

1734-5, Jan. 4, at night themerc. at 29.92 inc. lower than has been known by ^, and the
5. . . . night. 29.66 greatest storm of wind ever heard of in this age.


in the south of England, as also in France and

1736, Jan. 31 29.47

Feb. 1 29.15

2 28.39 rain

and stormy.

173*, Aug. 11 stormy.

Great Floods.
Before which the mercury falls very much.

1735, Sept. 4 29.7

5 29.6

6 night 29.6

7 29.25 The

greatest flood that has been at Coventry, being
about the middle of England, these 40 years, and
yet the mercury fell but little.
1735, Oct. 23 29.55

24 night 28.8

25 night 28.78

26 28.85

27 28.26

a great flood.

1735, Aug. 19 29.3

20 29.28

21 29.3

22 29-2

23 . . ., 29 2

'■ stormy, great rain.

24 • 29.38floods.

1735, Dec. 2 29.32 rain.

3 29-5 feir.

4 28.8 rain.

5 28.9 rain.

6 29.5 fair.

7 29.52 great

' Thunder. rains and floods.
The mercury seldom falls for rains that come
by thvmder. See diary, June 2, 1735.
When the mercury did rise.

1733, June 21 29.16 29.56

22 29.56 29.56

23 29.62 29.65 hot.

24 29.65 29.578ultry.

25 29.54 ... . . 29.52sultry.

26 29.51 29.59 great


27 29.57 29.56a very

violent thunder, from 10 in the morning to 1 in
the afternoon, doing great damages.

1735, June 1 29.3 29.8

2 29.4 29.55 thun-
der and great rains.
The mercury fell before it.

1733, July 27 29.44 hot, fair.

28 29.37 wind, rain.

29 29.09 violent thunder.



1734, Aug. 7 29 59 sultry.

8 29.46 fair.

9 ...... 39.25 thunder.

10 . 28.87 rain, thunder.

A frost, when the mercury is high, brings rain.
1731, March. The mercury was high all the
month, and no rain, but what followed the frost
the 17 th and 29th.

Dry Season.
In June 1729, and the mercury scarcely ever
above changeable.

In Aug. 1730, the mercury never lower than

1731, from the 1st to the 10th, and rain came
the 16th, though the mercury was rising.
A great frost, though the mercury fell ; but it
was attended with a great snow, which might
occasion it to subside.

1731, Jan. 1 29.56 rain.

2 29.46 20.12 rain.

3 28.78 28.72 wind.

4 28.72 28.81 frost, great


5 28-93 29.12 snow, frost.

Great Rains.
Though the mercury was rising.

1732, May 1 29 28 29.25 wind.

2 29.21 29.25 rain all day,

snow hard from 8 to 1 1.

3 29 34 29.0 rain.

4 29.09 29.09 rain.

3 29.12 29.34 wind.

6 29.44 29.46 fair.

7 .... 29.52. . . . 29.39 rain, and

great floods.

Great rain, though the mercury fell but little.

1733, 24 29.6 29.54 wind.

25 29.51.... 29.54 fair.

26 29.52 29.54 fair.

27 29.5 29.39 violent rain

for more than 1 1 hours.
Great Rains.
The mercury falling very much.

1734, July 10 ... . 29.65 29.67 fair. hot.

11 29.63 29.62 fair, hot

12 29.59 2.9.4 rain.

13 29.29 29.13 great rains.

^The mercury falling a great while before

the rain came, and the rain continued as long.

1736, May 19 29.75 fair wind 29.8

20 29 8 cold wind, fair 29.7

21 29.65 cold wind 29.52

22 29.39 wind, cloads,rain29.31

© 23 29.28 cloudy, fair 29.'^7

24 29:32 fair 29-35

25 ... . 29.32 clo. wind, rain 29.24

D 2


1736, May 26 .... 29-15 rain 29.15 The mercury below 28 inches.

27 29.12 rain 292 1734, Dec. 15, at 27.9.

28 -29.28 rain 29.23 1735, Jan. 8. at 27.9-

29 ... . 29.37 wind, cloudy, rain. In winter, before frosts, the mercur)' generally

1735, Feb. 22 29.43 rises pretty fast.

23 28.82 1735, Dec. 12.

24 ... . 28.9 Before a thaw the mercury falls.

25 28.76 great rain. 1735, Dec. 13.

Just after hot or sultry weather, the mercury 17.

generally falls. 1736, Feb. 9.

See 16 Sept. 1731. The mercury falls suddenly before a great snow.

8 Aug. 1734. 1731, Jan. 4.

After the aurora borealis, there generally follow 1736, Feb. 8.

high winds. 21.

27 Oct. 1733, a large aurora borealis, and the When the mercury falls for high winds, and

28th, 29th, and 30th, high winds. it continues to fall when that wind is come, it is

See 23 Jan. 1734. likely to be tempestuous, or continue some time.

The mercury falling pretty much, and neither unless rain succeeds,

wind nor rain succeeded. 1736, 22 Nov. . 29.62 fair, warm. . 29.62

1733, from the 18th to the 21st it fell 41, and 23 29.49 windy, warm29,32 wind.

no wind or rain at all till the 25th. 24 29.1 high wind .. 28.88 28.73

Sultry weather generally makes the mercury stormy,

fall soon after. Some of these collections are quite contradic-

1734, Aug. 8. tory to any settled rules, and such will happen.
After a great storm the mercury rises very fast, and others confirm them ; but he has collected so
1734, Aug. 11. very few of a sort, though the diary furnishes a
1736, Feb. 6. great many, that till more are in this manner
Before great winds the mercury falls very soon, collected, it will be very doubtful to form any
1734, Aug. 26. rules from them.

1736, Feb. 8.

An Account of a Sulphureous Vaporiferous Cavern in a Quarry at Pyrmont,
similar to the Grotta del Cane at Naples. By Mr. Misson and others. Com.
municated to the Royal Society by John Philip Seip, M. D. Aulic Councillor and
Archiater to the Prince of Waldech, and F. R. S. N" 448, p. 266.

An account of a sulphureous vaporiferous cavern in a quarry at Pyrmont,
near to the famous chalybeate springs. Birds, including poultry, and the
smaller quadrupeds, such as dogs, cats, &c. were suffocated on being exposed
for a sufficient length of time to the vapour emitted from this cavern, which
in this respect resembles the Grotta del Cane at Naples. When exposed to
this exhalation but for a short time, and afterwards brought out into the open
air, the animals commonly revived. A candle would not burn in this cavern.
[It would seem that this supposed sulphureous vapour consisted of the so called
fixed air, or carbonic acid gas.]

On the Effects of Dampier's Powder, in curing the Bite of a Mad Dog. By
John Fuller, Esq. Jun. F. R. S. N° 448, p. 272.

Mr. Fuller imagined the use of the lichen cinereus terrestris with black



pepper, had been so infallible a remedy for the bite of a mad dog, that there
needed no proofs of its virtue; he himself has used it on dogs, and always with
success; and some years since, a mad dog or cat had bitten some children and
their mother, at Battle: and mixing the lichen according to Dampier's direc-
tion, they all took it, as well as a dog or two that were bitten, and none of
them had any bad effects from the bite.

Christmas 1737, a neighbour's servant going to search whether a dog sus-
pected to be mad had been wormed, which dog died mad in 3 or 4 days after,
was bitten very much in both his hands; he went to a person, who had
great success in using the lichen cinereus tierrestris with pepper for the bite of
a mad dog. The man took his medicine every day; about 10 or 11 o'clock he
complained of a violent heat, and pain in his head, which Mr. F. suspected was
the effect of the bite, and not the medicine; but after he had taken it for such
a stated number of days, he grew better, and continued well ever after.

The man had tied his fingers with shoe-maker's ends, which are often used
for a cut ; and they were all very much inflamed, and very sore. Mr. F. made
him take them off, and all his plasters, and wash his hands with salt and water,
and in a fortnight's time they were quite well.

Another Case of a Person bitten by a Mad Dog. By David Hartley * M. A.
and Mr. Fr. Sandys. N° 448, p. 274.

About the latter end of Nov. 173'2, Mr. Soame's groom was bitten in the
hand by a mad dog, so as to fetch blood. It was not known in the family for
3 days. On the 4th day, when Fr. Sandys first saw it, the wound was healed;
but it was opened again by him, and kept so for some time, but at last healed
sooner than was intended, by the servant's neglect.

* Dr. David Hartley, better known by his metaphysical than by his medical writings, was bom in
1705. His father was a clergyman. After completing his education at Cambridge, where he pre-
pared himself for the {wofession of physic, he went to settle at Newark upon Trent, whence he
removed to St. Edmund's Buryj he afterwards came to London, and at last fixed himself in Bath.
From these frequent changes of abode, it may be inferred that he never got into very extensive

In 1739 he wrote a pamphlet in favour of Mrs. Stevens's medicine for the stone. His evidence
had great weight with parliament, who voted a large sum of money to Mrs. Stevens, the discoverer
of this supposed lithontriptic; which, however, did not long uphold the character that had been
given of it, and is now gone into disuse.

As a writer Dr. H.'s principal work is his Observations on Man, published in 1749; a work
replete with ingenious, but not always tenable, theories and opinions. The above, and another pap>er
on a case of calculus, are the only communications of his which are in the Phil. Trans. He died
in 1757.


He was bled, took a purge, after that -^ oz. of pulvis antilyssus, every morn-
ing for 3 days, and was ordered to go into cold water every day for some time;
but he neglected it after the 3d day. Besides, Fr. Sandys ordered him to for-
bear all meats, and drink nothing but water. He continued in this regimen
for about 5 weeks; then finding himself well, would confine himself no longer
to it.

On Jan. 7 following, he was seized with a sickness, vertigo, and faultering
in his speech and memory; and at last his vertigo increased to such a degree,
that he fell down twice in the space of half an hour; and the last time he did
not recover his senses, till he was put to bed, and blooded to the quantity of 18
or 20 oz. He continued all night restless and sullen, and in the morning was
blooded again, to the quantity of 13 oz. Dr. Hartley was sent for, and came
about 8 at night, and found him very sullen, thirsty, but averse to drinking,
and his pulse quick and hard. He ordered him to be put into the cold bath;
but he refused to comply with it, till he saw that force would be used. About
midnight his pulse rising, the Doctor ordered him to be blooded to the quan-
tity of l6 or [email protected] oz. he continued restless all night. About 8 in the morning
he went into the cold bath again: about 10 Dr. Hartley went away, leaving it
as his opinion, that the cold bath and bleeding should be freely repeated, as the
circumstances should require.

About noon Mr. Sandys came, and bled him immediately, to the quantity
of 18 or 20 oz. he continued restless all this night. On Mr. Sandys's asking
him whether his aversion to drinking proceeded from any pain in swallowing,
or some other cause? he said it was from a pain in swallowing. The next
morning his strength not being at all diminished, and his pulse continuing full
as vigorous as ever, Mr. Sandys bled him again to the quantity of 15 or 1 6 oz.
yet he still remained the same, and took the same care of his horses as usual.
Mr. Sandys went away, leaving orders that as long as these symptoms, viz.
restlessness, strength, and aversion to drinking continued, he should be blooded
freely, and put into the cold bath.

He was blooded twice more within the week, so that the whole quantity
which he lost in that time was about 1 20 oz. After the last bleeding his
symptoms disappeared, and he grew weak, low spirited and sleepy ; he then
went 8 times into the cold bath. He did not take any medicines during his
whole illness.

N. B. This person continued well anno 1738.


An Innuiry concerning the Figure of such Planets as revolve about an Axis,
supposing the Density continually to vary, from the Centre towards the
Suiface. By Mr. Alexis Clairaut, F. R. S, Translated by the Rev. John
Colson, F.R.S. N" 449, p. 277.

Notwithstanding that part of Sir Isaac Newton's mathematical principles of
natural philosophy, where he treats of the figure of the earth, is delivered
with the usual skill and accuracy of that great author; yet I thought something
further might be done in this matter, and that new inquiries may be proposed,
which are of no small importance, and which possibly he overlooked, through
the abundance of those fine discoveries he was in pursuit of.

What at first seemed worth examining, when on applying to this subject,
was to know why Sir Isaac assumed the conical ellipsis for the figure of the
earth, when he was to determine its axis? for he does not acquaint us why he
did it, neither can we perceive how he had satisfied himself in this particular :
and unless we know this, we cannot entirely acquiesce in his determinations
of the axes of the planets. It seems as if he might have taken any other oval
curve, as well as the conical ellipsis, and then he would have come to other
conclusions about those axes.

I began then with convincing myself by calculation, that the meridian of
the earth, and of the other planets, is a curve very nearly approaching to an
ellipsis ; so that no sensible error could ensue by supposing it really such. I
had the honour of communicating my demonstration of this to the R. S. at
the beginning of the last year ; and I have since been informed, that Mr.
Stirling, one of the greatest geometricians I know in Europe, had inserted a
discourse in the Philos, Trans. N° 438, where he had found the same thing
before me, but without giving his demonstration. When I sent that paper to
London, I was in Lapland, within the frigid iione, where I could have no re-
course to Mr. Stirling's discourse, so that I could not take any notice of it.

The elliptical form of the meridian being once proved, I no longer found
any thing in Sir Isaac Newton, about the figure of the earth, which could
create any new difficulty ; and should have thought this question sufficiently
discussed, if the observations made under the arctic circle* had not prevailed
on us to believe, that the shape of the earth was still flatter than that of Sir

* On a late examination and re-measurement of that part of the meridian, considerable errors
have been detected in the old measures; by which means those measures are brought to harmonize
and accord with all other measurements in different places, and yielding in the result a like figure
of the earth as those do.


Isaac's spheroid ; and if he himself had not pointed at the causes, which
might make Jupiter not quite so flat as by his theory, and the earth some-
thing more.

As to Jupiter, he says, (Page 4l6 of the 3d edition of Phil. Nat. Prin.
Math.) that its equator consists of denser parts than the rest of its body, be-
cause its moisture is more dried up by the heat of the sun. But as to the
earth, he suspects its flatness to be a small matter greater than what arises by
his calculation. He insinuates, that it may possibly be more dense towards
the centre than at the superficies. I am something surprised that Sir Isaac
should imagine, that the sun's heat can be so great at Jupiter's equator, when
it has no such eff^ect at that of the earth ; and that he does not ascribe each
to a like cause, by supposing that Jupiter also may be of a different density at
the centre from that at the superficies.

But whatever reason he might have for introducing two difl^erent causes, I
give the preference to the hypothesis which supposes unequal densities at the
centre and at the circumference. I have inquired, by the assistance of this
theory, what would be the figure of the earth, and of the other planets which
revolve about an axe, on supposition that they are composed of similar strata,
or layers, at the surface ; but that their variable density, from the centre to-
wards the circumference, may be expounded by any algebraical equation what-

And though my hypothesis should not be conformable to the laws of nature,
or even though it should be of no real use ; which would be the case, if the
observations made by the mathematicians now in Peru, compared with ours in
the north, should require that proportion of the axes, which is derived from
Sir Isaac's spheroid ; I thought however that geometricians would be pleased
with the speculations contained in this paper, as being, if not useful, yet
curious problems at least.

Part I. In which are found the Laws of Attraction, which are exerted on
Bodies at a Distance, by a Spheroid composed of Orbs of different Degrees
of Density.

Problem I. — To find the Attraction which a homogeneous Spheroid BNEbe,
fig. 9, pi. 6, differing hut very little from a Sphere, exerts on a Corpuscle

placed at a in the Axis of Revolution. 1. We may conceive the space

BNEiDMB, included between the spheroid and the sphere, to be divided into
an infinite number of sections perpendicular to the axe Kcb. Supposing then
that every one of the particles, which are contained in one of these elements
or moments snmu, exerts the same quantity of attraction on the body at a.

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