The Fairfield herald. [volume] (Winnsboro, S.C.) 1849-1876, 1866-08-01
Reply to rs" on the Wagon Wheel.

AS we promised, We now reply to
"S," to show that our position is the
true one in relation to Tie motion of
the wagon wheel. We will take up
tho seven points noticed in the comnu-
nication from ''S."
]. AS to the centre Of the hub bc;nn
tho centre Of the wheel, as it is in any
wheel used in machinery. This is
true as far as matter is concerned, but
III relation to motton there is an inn
portant difference. In il spinning
wheel the centre of the wheel and the
centre Of motion correspond, but
in wheel of a wagon, when the wag-
on moves upon the ground, The centre
Of motion drops as it were from the
axle or hub down 60 the ground.
2. The gronnd isnot the rcsistnmco
to be overcome. If there we're no
wheels, the ground would lc that re-
siStmcc, just as in Il Slcdgc, orwhcn
the wagon wheel is locked. The VERY
object of the wheel is to throw the re
Sistancc of the ground into the aNlc, so
that really the only resistance to be
overcome is the weight Of Tic wagon
frame with whntcvcr load may
be added, and what little friction
IS produced by tho axle in con-
tao; with the lower half Of the con-
cavity OF the hub. Upon "dcal"
level, the ground does not offer one
particle of resistance to The motion OF
the wagon.
But we will explain this further
under the next point to be made.
In regard to the toothcd wheel, the
power and resistance (or wUiplt. do
not bear The same relation as in n
wagon wheel.
In the toothcd wheel of machinery,
MnftfS MMnaGtcr fh and the 'SSh ecnhtrc th88 ooHA
agree precisely. IIcncc the rcsis-
tanco in that case is evidently at
the circumference Of the wheel. In
That case tho Resistance to be over
come is the secondary wheel. The
power being applied TO The primary
wnccl, il must commandments its motion
to the secondary wheel, dat is to the
wheel which cannot move until it's
leader, or the wheel to which the pow
or is applied, moves. But in the case
Of the wagon wheel, the inertia Of the
ground has not to be overcome, and
therefore there can be no rcSiataoa
on the ground against The motion of
the wagon.
In regard to the band used to COM
municatc motion from one wheel to am
other, il works on precisely the same
principle that the crank does. "A
band can communicate motion 60 II
wheel by hugging only onc-fourth Of
the wheel, or even, Us in case Of an
idlor, by simply running as a tangent
to the circumference of the wheel.
But Of course no practical use could be
made of this last motion produced By
tho band.
3. Now that the wagon wheel in mo-
ton acts just as q series of levers
would, we will attempt to show.
Perhaps the most practical illnstra-
ton will be this: :
Suppose the tire and tho fellows re-
moved entirely from the wheel, and
that nothing is left but the hub with
all the spokcs. Call the one upon the
ground Mol, and the ono directly OPP
posite to it No. s. Start the wheel in
motion, and observe the rclutivc
movements of Nos. | and 8. The first
sticks to single point upon the
ground while the second moves
about ii observe, not around it in the
arc ofa circle, but in thc arc OF an
cccchlrlc. NO. moves lrOE. cCD-
tain point in the rear of The porpcn-
dicular drawn to the point Of contact
with No. | and the ground, and contin-
ucs to move forward toa certain point
in front of the same pcrpcndcu!ar,
while all this time No. | has not NOV
cd one inch. Now tho space passed over
by No. 8 will bo in proportion 30 the
distance from the point to point 8,
in other words, to the diameter Of the
wheel. The motion of the wheel thus
far is just like that Of " straight stick
with ono end resting Oh the ground
md tho other held and moved by hand
backwards and forwards. Now IN
crease tho rapidity Of tho wheo
stripped of its tiro and follows, and
tho samo principle holds good that is
every spoke which touches the ground,
during the time of contact, is the con-