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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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could not produce a regular motion from east to west, about the ball in the
centre, having his hand supported, as usual, on the back of a chair. He
found he could produce a very regular one from east to west for many revolu-
tions, and change from one motion to another, without being sensible he
moved his hand at all.

He then wet the ball and string, as in the experiment beforementioned, and
found he could tire himself with a motion either from east to west, or from
west to east, as he pleased, without giving any motion, that he could perceive,
to his hand or fingers. Hence many odd experiments that please, may, when
repeated, succeed.

Since therefore the motion of the pendulous body, from a point undoubtedly


fixed, is irregular, as he found by many different experiments, repeated
with the greatest care and caution; and since he was convinced from these last
mentioned trials, the motion from west to east, and from east to west, must
generally have been determined by himself: he is inclined to think, that a
desire of producing a motion from west to east, was the secret cause that de-
termined the pendulous body to that direction, by some impression from Mr.
Gray's hand, as well as his own, though he was persuaded at the same time,
he was not sensible of giving any motion to his hand himself: and he the
rather thinks this was the case, from the instance Mr. Gray gives, by way of
explanation, of a man resting his elbows on his knees, this implying that he
rested his arm on his elbow, as Mr. W. did himself.

But though upon the whole it does at last appear, that this motion from
west to east in a pendulous body, applied to another in the centre of an electric
area, is to be ascribed to the hand that holds it, and not solely to the nature
of the electric effluvia, or the figure of the central body ; yet still, perhaps, it
may not be improper for astronomers to consider, whether or no a medium
with this property, that all bodies immerstd in it, are repulsive of one another,
ought not to be joined with gravity to explain the heavenly phaenomena; espe-
cially since the phaenomena of fire, and our electric effluvia, have a great
affinity to each other; and since many of the heavenly phaenomena are to be
accounted for, on this supposition, with great simplicity; and some of them,
that have not yet perhaps been fully accounted for, seem necessarily to

Of the Ivfluence which two Pendulum Clocks were observed to have on each other.
By Mr. John Ellicott, F.R.S. N° 453, p. 126.

'- The two clocks, on which the following observations were made, being de-
signed for regulators, particular care was taken to have every part made with all
possible exactness : the two pendulums were hung in a manner different from
what is usual ; and so disposed, that the wheels might act on them with more
advantage. Upon trial they were found not only to move with greater freedom
than common, but a heavier pendulum was kept in motion by a smaller weight.
They were in every respect made as near alike as possible. The ball of each of
the pendulums weighed above 23 lb, ; and required to be moved about 1° 5' from
the perpendicular, before the teeth of the swing wheel would scape free of the
pallets ; that is, before the clocks would be set a going. The weight to each
was 3 lb. which would cause either of the pendulums in their vibrations to de
scribe an arch of 3". The two clocks were in cases, which shut very close.


and placed sideways to each other, so near that when the pendulums were at
rest, they were little more than about two feet asunder.

The odd phaenomena observed in them were these : in less than two hours
after they were set a going, one of them, called N° 1 , was found to stop ; and
when set a going again, as it was several times, it would never continue going
two hours together. A.s it had always kept going with great freedom, before the
other clock, N° 2, was placed near it, this led Mr. E. to conceive its stopping
must be owing to some influence the motion one of the pendulums had upon
the other ; and on watching them more narrowly, the motion of N° 2, was
found to increase as N'' I diminished ; and at the time that N° 1 stopped, N° 2
described an arch of 6°, that is nearly 2 degrees more than it would have done,
if the other had not been near it, and more than it moved in a short time after
the other pendulum came to be at rest: this made Mr. E. imagine that they had
a mutual influence on each other.

On this he stopped tiie pendulum of N° 2, leaving it quite at rest, and set
N° 1 a going, the pendulum describing as large an arch as the case would per-
mit, viz. about 5°. In about 20 minutes after, he went to observe whether
there was any motion communicated to the pendulum N° 2, when, to his sur-
prise, he found the clock going, and the pendulum to describe an arch of 3",
whereas at the same time N° 1 did not move 4°. In about half an hour after,
N° 1 stopped, and the motion of N° 2 was increased to very near 5°. He then
stopped N° 2 a second time, and set N° 1 a going, as before ; and standing to
observe them, he presently found the pendulum of N° 2 begin to move, and
the motion to increase gradually, till in 17'" 40* it described an arch of 2° 10',
at which time the wheel discharging itself of the pallets, the clock went.

The arches of the vibrations continued to increase, till, as in the former ex-
periment, the pendulum moved 5°; the motion of the pendulum N° 1 gradually
decreasing all the while, as the other increased ; and in three quarters of au
hour after, it stopped.

He then left the pendulum of N° 1 at rest, and set N° 2 a going, making it
describe an arch of 5° ; it continued to vibrate less and less, till it described but
about 3°; in which arch it continued to move all the time he observed it, which
was several hours. The pendulum of N° 1 seemed but little affected by the
motion of N° 2,

Mr. E. tried these experiments several times over, without finding any re-
markable difference. The freer the room was from any motion, as people's
walking about in it, &c. he found the experiments to succeed the better ; and
once he found N° 2 set a going in 16™ 20*, and N^ 1 at that time stopped in
36"" 40«.

VOL. viii, Tt


Further Observations and Experiments concerning the two Clocks ahovementioned.

By the Same. N" 453, p. 128.

The seemingly different effects, which the two clocks had on each other,
Mr. Ellicott accounts for as follows.

The manner in which the motion is commimicated to the pendulum at rest,
he conceives to be thus: as the pendulums are very heavy, when either of them
is set a going, it occasions by its vibrations a very small motion, not only in the
case the clock is fixed in, but, in a greater or less degree, in every thing it
touches ; and this motion is communicated to the other clock, by means of the
rail, against which both the cases bear. The motion thus communicated, which
is too small to be discovered but by means of some such-like experiments as
these, may be judged by many, insufficient to make so heavy a pendulum de-
scribe an arch of 2°, or large enough to set the work a going ; and indeed it
would be so, but for the very great freedom with which the pendulum is made
to move, arising from the manner in which it is hung. This appears from the
^erysm air weight required to keep it going, which, when the clock was first put
together, was little more than 1 lb. And if the weight was taken off, and the
pendulum made to swing 2°, it would make J 200 vibrations before it decreased
half a degree, so that it would not lose the 3000th part of an inch in each
vibration. Indeed if the weight was hung on, the friction would be increased,
and the pendulum would not move quite so freely ; but even in that case it was
found to lose but little more than the 2000th part of an inch, or about 3
seconds of a degree, in one vibration ; and therefore if the motion communi-
cated to it from the other, will make it describe an arch exceeding 3", the vi-
brations must continually increase till the work is set a going. And that the
motion is communicated in the manner above supposed, is confirmed by the
following expeciments :

A prop was set against the back of the case of N° 2, to prevent its bearing
against the rail ; and N° 1 was set a going ; then observing them for several
hours, Mr. E. could not perceive the least motion communicated to N°2. He
then set both the clocks a going, and they continued going several days ; but
he could not find they had any influence on each other. Instead of the prop
against the back of the case, he put wedges under the bottoms of both the
cases, to prevent their bearing against the rail ; and stuck a piece of wood be-
tween them, just tight enough to support its own weight. Then setting N° 1
a going, the influence was so much increased, that N° 2 was set a going in less
than 6 minutes, and N° 1 stopped in about 6 minutes after. In order to try



what difference would arise, if the clocks were fixed on a more solid floor, he
placed them, exactly in the same manner as in the last experiment, on the stone
pavement under the piazzas of the Royal Exchange, and stuck the piece of
wood between them, as before ; and setting N" ) a going, the only difference
was, that it was 1 5 minutes before N° 2 was set a going, and N° 1 continued
going near half an hour before it stopped.

From these experiments Mr. E. thinks it plainly appears, that the pendulum
which is put in motion, as it moves towards either side of the case, makes the
pressure on the feet of the case to be unequal, and, by its weight, occasions a
small bearing or motion in the case on that side towards which the pendulum is
moving; and which, by the interposition of any solid body, will be communi-
cated to the other clock, whose pendulum was left at rest. The only objection
to this, he conceives, is the different effects which the two pendulums seemed
to have on each other. But this he hopes to explain to satisfaction. -^

For, notwithstanding these different effects, he soon found, by several
experiments, that the two clocks mutually affected each other, and in the same
manner, though not with equal force ; and that the varieties observed in their
actions on each other, arose from the unequal lengths of their pendulums

For, on moving one of the clocks to another part of the room, and setting
them both a going, he found that N° 2 gained of N° 1, about l™ 36* in 24
hours. Then fixing both against the rail, as at first, he set them a going, and
made the pendulums to vibrate about 4° ; but he soon observed that of N" 1 to
increase, and that of N° 2 to decrease ; and in a short time it did not describe
an arch large enough to keep the wheels in motion. In a little time after it
began to increase again, and in a few minutes it described an arch of 2°, and
the clock went. Its vibrations continued to increase for a considerable time,
but it never vibrated 4°, as when first set a going. While the vibrations of
N° 2 increased, those of N° 1 decreased, till the clock stopped, and the pen-
dulum did not describe an arch of more than 1° 30'. It then began to increase
again, and N" 2 decreased, and stopped a second time, but was set a going
again, as before. After this N° 1 stopped a second time, and the vibrations
continued to decrease till the pendulum was almost at rest. It afterwards in-
creased a small matter, but not sufficiently to set the work a going. But N*^ 2
continued going, its pendulum describing an arch of about 3".

Finding them to act thus mutually and alternately on each other, Mr. E. set
them both a going a second time, and made the pendulums describe as large
arches as the cases would permit. During this experiment, as in the former, he
sometimes found the one, and at other times the contrary pendulum to make

T T 2


the largest vibrations. But as they had so large a quantity of motion given
tiiem at first, neither of them lost so much during the period it was acted on
by the other, as to have its work stopped, but both continued going for
several days, without varying one second from each other ; though when at a
distance, as was before observed, they varied 1"" 36* in 24 hours. While they
conthiued thus going together, he compared them with a third clock, and found
that N° I went !•" 17' faster, and N° 2 went ig' slower, than they did when
placed at a distance, so as to have no influence on each other.

On altering the lengths of the pendulums, the period in which their motions
increased and decreased, by their mutual action on each other, was changed ;
and would be prolonged as the pendulums came nearer to an equality, which,
from the nature of the action, it was reasonable to expect it would. This dis-
covers the reason why the pendulum of N° 2, when left at rest, would be set a
going by the motion of N° 1 ; whereas if N° 1 was left at rest, it would not be
set a going again by the motion of N" 2.

For he found, by several experiments, that the same pendulum, when kept
in motion by a weight, would go faster, than when it only moved by its own
gravity. On this principle, which may easily be accounted for, it follows, that
during the time in which the shortest pendulum, N° 2, was only acted on by
N° 1 , it would move slower, and the times of its vibrations approach nearer to
an equality with those of N" 1, than after it came to be kept in motion by the
weight ; and by this means the time which N° 1 would continue to act on it,
would be prolonged, and be more than was required to make the pendulum de-
scribe an arch sufficient to set the work a going. But, on the contrary, while
the pendulum of N° 1, which was the longest, was only acted on by N' 2, as
it would move slower, the difference of the times of the vibrations would be
increased ; and consequently the time which N° 2 would continue to act on it,
would for this cause be shortened, so that before the pendulum of N° 1 would
describe an arch sufficient to set the work agoing, the period of its being acted
on would be ended, and it would begin to act on N° 2, at which time its vibra-
tions would immediately decrease, and continue to do so till it came to be
almost at rest. And thus it would continue, sometimes to move more, and at
other times less, but never sufficiently to set the clock a going.

A Wound in the Cornea of the Eye successfully cured. By Mr. Thomas Baker,
Surgeon to St. Thomas's Hospital. N''453, p. 135.

A young woman, about 15 years of age, on the 6th day of Nov, 1733, re-
ceived a wound just in the pupil of her right eye, by the point of a common


fork. An inflammation followed, with great pain. The whole eye appeared
dark and turbid ; and the humours seemed confused, and blended together.
Mr. B. opened a vein in the arm, and drew away 10 oz. of blood : he then
washed the eye with a collyrium of trochisci albi rhasis, and common water,
made blood-warm ; and dressed it with a cataplasm of white bread and milk,
with a little saflron in it. The next day there appeared on the wounded part of
the cornea, a large thick slough : he dressed it in the same manner ; and so
continued till the ] 8th day of the same month, when the slough cast off. He
purged her during this time with decoct, sennae §ij, mann. solut. Jss, aq. paeon,
comp. 3ij ; m. f. potio, at the distance of about 3 days, just as he found her
strength would permit. The inflammation and pain abated daily. During the
whole time, the eye was quite blind, till the slough cast off, when she com-
plained she saw double. In a very little time her sight returned, but not so
perfect as before ; her eye having somewhat of a cloud before it.

He made her 6 visits at the distance of '2 or 3 days, after the 18th : when he
left her, she saw perfectly well, that cloud which she before complained of,
being removed ; her eye appeared fair and clear, and equally strong and useful
to her as the other. A little speck, which was the cicatrix of the wound, re-
maining on the cornea, he made her a fontanel in the arm, and ordered her to
keep it open, and not to touch the speck on her eye. More than 2 years after-
wards, the speck had gradually decreased, and was so small, that it was scarcely
visible ; and her sight was as perfect and strong as before the accident.

jin Account of a monstrous Boy. By Andrew Cantwell, M. D. dated Mont-
pelier, Dec. 17, 1731, n. s. N°453, p. 137.

There was at the above date at Montpelier, a boy 13 years of age, born at
Cremona, who bore the lower parts of another boy, which seemed to issue from
his epigastric region, between the cartilage ensiformis and the navel. The fore-
part of the one faced that of the other. The head and trunk seemed buried in
the boy's abdomen, down to the hips, where the connection was plainly to be
seen. This portion of the prominent body had a well-formed anus and penis.
The scrotum had a fine down on it, but was void of testicles, and seemed to be
filled with the intestines. Nothing passed through these 2 outlets. Dr. C.
could perfectly well distinguish the 2 ossa iliClm in their natural state, but
could not feel the os sacrum. The articulation of the femur was somewhat dis-
cernible on each side : and Dr. C. perceived the pulsation of the anterior crural
arteries. The boy felt very sensibly when these additional feet, legs, or but-


tocks, were pinched, or over-much pressed. He had lately had the small-pox,
and these had suffered by it equally with him. At his navel Dr. C. found a
considerable rupture, which was covered by this portion of a body. This
rupture would grow monstrously large in wet weather, and would diminish again
in dry. It had a circular hole in it, which ran through the peritonaeum. The
boy was of a thin habit of body, but otherwise enjoyed good health. His
father told the Doctor that this was the 7th child his wife bore him. She was
30 years of age at his birth, and bore hin) 2 more afterwards. All the rest were
of the natural shape.

Three extraordinary Cases in Surgery. By Bezaleel Sherman, Surgeon, at
Kelvedon in Essex. N° 453, p. 138.

Samuel Bush, being. on the top of a very high timber tree, in order to shake
down the acorns, he let go his hold ; and by falling from one bough of the tree
on another, he broke his thigh-bone ; and one end of it, by the force of the
fall, stuck fast in the ground, which fractured the bone in another place, about
2-^ inches above the former. This entire piece of the os femoris was taken out;
notwithstanding which, so large a callus united the two ends of the bone, that
his thigh, when cured, was very little more than a quarter of an inch shorter
than the other thigh. The surgeon who had the care of him, used his utmost
endeavours, during the cure, to preserve the extension; but he imputed the
largeness of the callus to a very great quantity of lap. osteocolla, which he
made him take for 6 weeks or 2 months, in powder with milk, in an electuary,
in his bread, and in his pudding ; in short, in almost all the food he took.

One Fitch, of the parish of Kelvedon, had a foul ulcer in his mouth, with a
caries in the lower jaw-bone, one part of which, from the suture at the chin to
the end of it under the ear, in process of time entirely came out, with '3 teeth
in it. This was also owing to a great quantity of osteocolla internally given,
which was thought not only to expedite this large exfoliation, but at the same
time to generate so large and firm a callus, that he can chew a hard crust, or
any other food, on that side, as well as on the other.

John Spilnian, had a sinuous ulcer in his rectum, about 2 inches from the
anus. This had remained a twelvemonth, and was taken for the piles, and
treated as such, both internally and externally. Mr. S. soon perceived a tumour
in his buttock, 2 or 3 inches from the anus, which coming to suppuration, he
opened it by incision ; and after dressing it several weeks with little prospect of
success, he discovered at the bottom of the ulcer something that looked like a
bone, which when extracted, proved to be the lower jaw of a fish, as a whiting.


or young cod, &c. And unquestionably this was swallowed at least a year be-
fore it came away, because the pricking pain he felt when the sharp end of the
bone stuok. in the rectum, was the symptom mistaken for the piles ; and when
this had made its way through the rectum, and got into the fleshy part, the
aposthume followed in course; and the bone being extracted, the ulcer was
soon cicatrized by the common methods of cure in such cases.

Account of a Woman, 68 Years of Age, who gave Such to two of her Grand-
children. By Tho. Stack, M. D. N° 433, p. 140.

A gentleman of credit having informed Dr. S. of a woman near 70 years old,
who suckled one of her grand-children, his curiosity was excited to see so un-
common a sight ; and the more, in order to try if he could not discover some
fallacy in the affair. Wherefore he went in company with the gentleman, to a
house in Tottenham-Court-Road, where the woman they inquired for appeared
in an instant. Her breasts were full, fair, and void of wrinkles ; though her
face was very much withered, her cheeks and mouth vastly sunk in, her eyes
red, and running with a clammy humour ; and though she had in short, all the
other external marks that one might reasonably expect to find in a woman, who
had spent the last half of her past life in labour, troubles, and other concomi-
tants of poverty, and through them had reached nearly to her 70th year. On
pressing her right breast, she fairly squeezed out milk, which gathered in small
drops at 3 of the lacteal ducts terminating in the nipple. This experiment Dr.
S. made her repeat a 2d time, having himself carefully dried the end of the
nipple with his handkerchief, as he had done before her first trial. Con-
vinced of the truth of the fact, he asked her several questions about her case.
The substance of her answers was as follows :

Her name by marriage was Eliz. Brian. She was in the 68th year of her age,
and had not borne a child for 20 years and upwards. About 4 years before, her
daughter being obliged to leave an infant she then gave suck to, in the care of
this her own mother, and likely to be a considerable time absent ; the old wo-
man, finding the child froward for want of the breast, applied it to her own,
barely in order to quiet the infant, without the least thoughts of milk. And
this having reiterated several times, a son of hers, by that time grown a man,
perceived that the child seemed to swallow somewhat from the nipple; on which
he begged leave of his mother to try if she had not milk. The experiment suc-
ceeded : the youth drew milk from that same breast from which he had been
weaned above 20 years, and which had been unaccustomed to any for 17 or J 8
years before : the good woman then continued to suckle her grand-child in


earnest : and after some time her daughter, viz. the infant's mother, seeing she
was provided with such an extraordinary and tender nurse, was emboldened to
bid fair for an increase of issue, which till then she knew not how to nourish or
provide for. Accordingly, at the end of 2 years, she brought forth another
child ; on which the grandmother weaned the first, and suckled the latter ;
which she had done for the last 2 years, and continued to do. And this infant,
in Dr. S.'s presence, took the nipple with as much eagerness, and seeming de-
light, as he ever perceived in a child of 2 years old ; and at it plainly performed
the actions of suction and deglution. The 2 children, both girls, are, as to
constitution, such as he could wish to the dearest friend ; plump and firm
in flesh; in complexion cleanly, fair and healthy, and in temper brisk and
sprightly ; considering the lowness of their condition and education, and the
mean diet of the nurse.

When this good woman came to town, which was near 2 years before, her
milk abounded to that degree in both breasts, that, to convince the unbelieving,
she would frequently spout it above a yard from her : a particular which, among
others, the good man and woman of the house, and others of the neighbour-
hood, likewise assured him of. At the above date her left breast became dry,

Online LibraryRoyal Society (Great Britain)The Philosophical transactions of the Royal society of London, from their commencement in 1665, in the year 1800 (Volume 8) → online text (page 38 of 85)