The Calhoun chronicle. [volume] (Grantsville, W. Va.) 1883-1984, 1914-06-11
TANNING THE SAILS
No Amount of Wind Raised
Aboard a Ship Can Propel 1t.
CONTRARY TO NATURAL LAW.
A a Matter Of Fact, the Force of the
Air Driven Against tho Canvas
Would Have a Tendency to Send tho
Vessel Backward Instead Of Forward.

Air Driven Against tho Canvas
Would Have a Tendency to Send tho
Vessel Backward Instead Of Forward.
III an electric fan could be made
large enough to throw sufficient
amount OF wind to move small sail
boat and such a fan was placed on the
end OF boat with the wind from the
fan blowing against the sail on the
very boat the fan is on. is It possible
that 1t could move the boat? The ar.
gument is that the fan. being on the
same boat as the sail, cannot move
itself. But as the air detaches itself
from the fan and hits the sail, my idea
Is that 1t can, provided 1t has the
strength to move the boat. Please give
an answer"
This question Is worth answering be-
cause II involves a principle of physics
that ought to be universally under
stood and ignorance of which may lead
to the waste OF both time and money
upon Inventions that will not work.
The writer Of the question thinks
that because the air, as she expresses
1t, Is detached from" the fan when 1t
starts off to strike the sail, it ought to
act like an ordinary wind and push the
boat before ii. But she would not think
so IL she reflected that the particles OF
air driven from the fan resemble a
swarm OF bullets shot from gun.
The air particles get their force from
the fan as the bullets get theirs from
the gun, and just as the gun recois
with force equal to that which it i'm.
parts to the bullets, SO the fan, wheth.
er driven Icy electricity or steam or
turned by hand, inevitably recoils with
the same amount of force that it i'm
parts to the air
10 make clearer the comparison be-
tween stream of bullets from gun
and stream OF wind from an electric
fan, imagine a Maxim gun placed at
the rear OF a boat and an impenetrable
target at the front, and then suppose
that the gun should hurl continuous
current OF bullets against the target
Anybody can see that the boat would
not be driven forward, because the
recoil OF the gun would constantly
force it backward with the same
energy with which the bullets. striking
the target, forced 1t ahead.
But IL the gun were placed on shore
or on another support its stream of
bullets striking the target would drive
the boat forward, because then their
effect would be like that OF wind
blowing freely across the water and
having no connection with anything on
the boat
An ordinary wind Is able to drive a
boat whose sail it strikes because its
reaction Chat OF the wind) Is not upon
the boat. but upon the great mass of
the atmosphere or upon the earth.
The principle to be remembered,
and ignorance or forgetfulness OF
which has cost the happiness OF more
than one uneducated inventors life, is
that no mechanical force can be pro-
duced without an expenditure Of en-
ergy precisely equivalent. Never for
get that there can be no action with
out equal reaction and that IL the ac-
ton takes its origin within the limits
or the thing that Is acted upon the
'SoSnVh WIZ diSO De lelt WllnlD tuOSe
same limits.
Your electric fan would drive a toy
vessel placed on the deck of your
boat. although 1t would not drive the
boat Itself. because. with regard to
the toy vessel. the breeze from the fan
would have an Independent origin. like
an ordinary wind blowing over a lake
70
the toy. but upon the boat over whose
deck the toy glided.
IL you are inside a car and push upon
the car you cannot move 1t as you could
II you stood upon the ground outside
and pushed. In the first case your
action and reaction are both upon the
car. but In the second case the action
Is upon the car and the reaction upon
the ground outside. The same thing
happens II you suspend bar above
your head and lift yourself by pulling
down on 1t, and afterward put the bar
under your feet and try to lift yourself
by pulling up on IL. Yon succeed In
lifting yourself in the first case, but
you fail In the second. because when
the bar is under your feet the force
OF your pull reacts upon your own
body and urges it down Just as much
as up.
There is one effect OF the electric fan
which might surprise you-it would
tend to drive your boat backward in.
stead Of forward. 1t would push
against air like the propeller OF an
aeroplane. and to make It drive your
boat forward you would have to face
the fan around. so that its reaction
would be upon the atmosphere behind
instead OF ahead OF the boat and IN
either case your sail would be not only
useless but an encumbrance.- Garrett
7. serviss ia New York Journal.