The enquirer. [volume] (Richmond, Va.) 1804-1815, 1809-05-12

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any other Q: Not 50 many q ss,ions at once,
my friend. We must FIRST fix on some general
standard of velocity. What do you mean by one
Things moving faster than another how do you
know it does Let Us judge it by the favorite
speed ofrace-herses. How do you know. that
Wrangler run faster, last Monday week than
Faaafox E. The thing il plain enough. They
satt of together, and Wrangler came through
hrst. Q Thst is, he ran over the course in shor-
ter time, than his competitor. Did he not run
fHster in the Same rime E. No doubt of 1T. @
Then, fyou set two things oHin the same direc-
uon, at the same time, and stop them at the same
time, you determine that A had moved faster than
D. because it has gone farther. lfthey move in
different directions at the same time, you apply
the same rule. Ifthey go in different directions,
and different times, it is still the same. You as
Certain by calculation, how far each of them had
gone in the same time, as a minute or second, &
determine how much faster A. moved than B. E.
Wen, who doubts it Q: No man of sense can.
The general rule then is, you are to determine
the relative velocites of all bodies by the rela-
tive distances over which they move in the same
time. +. Certainly. But does not every part of
the wheel move over the same distancel Q.
softly We must try a simpler experiment than
that of the wheel. fix this stick in the earth
move il backward and forward. The ground
becomes its axis or centre of motion. 1t is now
lever of the 2nd sort. Which moves the fast
est-the upper or the lower part of the stick
Which goes the farthest iii the same time E.
Surely the upper; because it describes the
greatest circle! .: Then you admit that one part
OF the same connected thing may move faster than
another This is so true of the vane of wind
mill, that the eye cannot pursue the revolutions Of
its extreme ends, although it may easily traceithe
turns OF the parts nearer to the centre of mo-
ton.
(. But the wheel! the wheel!
. Well, sir, was about to proceed from nv
lever to your wheel. The one serves to recon-
cile the mind to the other roll this dollar o.
YER the point of this pin, inserted into your table
You see tina; the point OF the pin is for the mo-
ment the Center of motion. The whole dollar
turns, as 1T were, upon it, although the dollar is
shifting ITS relative place upon the table. Does
not the upper parto of the del.ar, like the upper
part OF the lever, moving farther from the tempo
rary center OF motion, describe larger circle,
n,o7e ETfhsr, in the same tire than the lower part
T. In that experiment, it cannot be denied. O.
so, II you make wheel move over a nail inserted
in the earth, does it not produce the same results
IL instead OF nail, you place there pointed
pebble, sharp chip, any thing, Is it not the
same l.. Pshaw ! But is not the wheel con-
hauaily turning upon the ground, though it meets
there with no kind of obstruction. The point of
your nail is not always there, for the wheel to
you call the center of motion.
turnover at all , L. Sir, do you mean to Insult
my understanding by such trifiing question Q.
Far from II. The question which ven consider so
trihng, has ensrossed the attention of the pro.
founaest philosophers. Have you ever read Hell,
sham's Lectures in Natural Philosophy. E.
Who is he Q. An Irishman! whose elemen-
tary work III Philosophy is, in myjudgement, the
most profound treatise the subject. II is short,
sir, read it. Re has deigned to devote whole
page, his lS2d s. Diagram, TO this simple point.
His explanation is, that if the point A touches
the earth, & L is On the top Cf the wheel, & apow-
er, as a horse, is applied to the axle to draw the
wheel along i'll any direction, Sc the motion of the
point will be retarded by the resistance arising
from friction, whilst the point b, which meets
with no resistance is carried forward, without I.
ny retardaton IT It's motion, and consequently
nusr move forward faster than the point Az
hclshan,, you SEQ, eNbiieitiv asserts my prnici-
pie j but rs all the part, of the wheel coherc,
the point B'cannut move forward faster than the
POINT a, unless the wheel revolyes about its axis
and SO on YOU see then the reason for its revo-
utlohis, TIC r;GtioH OF distractions which il meets
with cr'the ground. If there was no obstructi-
on, 1T woG!d aercr bcgui % turn. On polished
frrfectly smooth plain Of glass, there would be
none lhe wheel m'gni progress, like wheel
'oc!iSd by W a2Soncrs, bnt ike that, 1T would me-
yer revoirc L. i ADMIT Ii. The little inequali-
'cs OF t!.e earth, It's little projections which fall
"'ac cSi!ieS OF the wheel, tlie causes of its
re'oiuiIon . Truc, then you concede that
Nesr are The documentary centres ofmotion, round
which the whole turns. The perpendicular dIa-
meter becomes pro fsa1. my lever moving ON
tins point. 1t is the longest lever i'll the whoie
wheel, II the wheel were supposed divided into a
100 sPokes-tlie top of the wheel is the fartleyt
from the pivot of motion, and, OF course, moves
farther and faster, than any other point. 1t is
so with the other semi liameters below the hori-
zontai diameter, rs they are nearer the ground.
Know that this pivot OF motion is continually
shi ting-the Wheel after it has past over one in
equality, cones to aDOt!ier-this sho WE, that the
.ower parts ofthe wheel are the piyots on which
the upper are successfully moving. And this
she VS. the reacoa OF this superior velocity of the
upper parts. l.. But is not the axe-tree the CEN
II" OF motion Q. II is true, that the parts are
moving relgtivs:2 round that--but they also
move relatively TO the Earth--with this differ
ci!ce; TIC lower parts have "A rotatory and reIa.
ti'eiy retarded mStioii-the upper, a rotatory &
rtntive. accelerated motion. use relatively
dert,a % the upper and lower parts. While the
DDttom tf The wheel turns round the axle reia-
tHeiy, sodocS the top; both go farther every mo.
meet on t6esr course, but the top goes faster
liah the bottom. II is true, ifthe number of re-
'oiiiuons DC entire, one point on the whole
"'"ves farther or faster than auy other, because
thet top becomes the bottom, and the bottom the
tOP-hrst one goes the fastest, then the other
just as one foot of man moves first, and then
tue o'her--but 80 long as any one point is at he
top, and tile other at tile bottom, the top moves
with the most velocity. This is the precise pro-
position and no other
Bst, will showyou by I'm experiment, how
1t Is. IL. An experiment. Quotha Well let's