The Hartford republican. (Hartford, Ky.) 18??-1926, 1914-03-27
TANNING THE SAILS
No Amount Of Wind Raised
Aboard a Ship Can PropeI II.
CONTRARY TO NATURAL LAW.
A. a Matter Of Fact, the Force Of the
Air Driven Against the Canvas
Would Have a Tendency to Send the
Vessel Backward Instead Of Forward.

Vessel Backward Instead Of Forward.
III an electric fan could be made
large enough to throw sufficient
amount of wind TO move a small sail
boat and such II fan was placed on the
end of n boat with the wind from the
fan blowing against the sail on the
very boat the fan is on. IL IL possible
that il could move the boat: The ar.
gument is that the fan. being on the
same boat us the sail. cannot move
itself. But rs the air detachcs itself
is that it can. provided IL has the
strength to move the boat Please give
IN answer"
This question is worth answering be-
cause 1t involves Il principle of physics
that ought to he 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
It. is detached from" the fan when 1t
starts Off to strike the sail. IL ought to
act like an ordinary wind and push the
boat before it. But she would not think
so IL she reflected that the PARTICLES Of
air driven from the fan resemble
swarm of bullets shot from u gun.
The air PARTICLES get their force FROM
the fan us the bullets get theirs from
the gun. and just rs the gun recOils
with II force equal to than which ii i'm
parts to the bullets. so the fan. wheth-
er driven 10y electricity or steam or
turned 10y hand. inevitably recoils with
the same amount of force that ii i'm.
parts to the air
To make clearer the comparison be
tween u stream of bullets from a gun
and stream of wind from an electric
fan. imagine Il Maxim gun placed at
the rear OF a boat and an impenetrabl
target at the front. aud then suppose
that the gun should hurl n continuous
Anybody can see that the boat would
not be driven forward. because the
recOil OF the gun would constantly
force il backward with the same
energy with which the bullets. striking
the target. forced it 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 lie like that of II wind
blowing freely across the water ana
havln. no connection with anything on
the boat.
An ordinary wind is able to drive II
boat whose sail it strikes because it,
reactiOn tthat of the wind, is not upon
the boat. but upon the great mass OF
the atmosphere OF 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
dnced without an expenditure Of en-
ergy precisely equivalent Never for
ee< tAat there eea ~ NO aetioo WttA-
1ut eouci reaction and that II the &C.
tioa takes tn origin within the limits
" the thing that IL cctei upon the
reaction will EisO be felt within tkoGc
same limits.
YOnr electric fan would drive q toy
vessel placed on the deck OF your
boat. although II would not drive the
boat itself. because. with regard To
the toy vessel. the breeze from the fan
would have I'm Independent origin. like
an ordinary wind blowing over a lake.
and its reaction would not be upon
the toy. hut upon the boat over whose
deck the toy glided.
, Ii yOu are inside car and push upon
the car You cannot move it as you could
II you stood upon the ground sutside
and pushed. In the first case your
action and reaction are both upon the
ear. but In the second case the action
Is upon the ear and the reaction upon
The ground outside. The same thing
1apppns IL you SUSPEND Il bar above
yonr head and lift Yourself by pulling
DOWN on il. and afterward put the bar
rnder yonr feet and try To- lift Yourself
by pulling up on il. You succeed in
illing Yourself in the brSt case. but
vou fail in the SecOnh because when
the bar Is under Your feet the force
II Your phil reacts upon yOnr own
body and urges it down just as much
rs up
There Il Que effect OF the electric fan
which might surprise yuu--it would
tent 10 drive your boat backward IN
stead of forward II would push
against air like the propeller of IN
teroplane. and Ia make il drive your
boat forward you would nave Ia face
the fan around. So that ats reaction
would be upon the atmosphere behind
instead Of ahead OF the boat. ana in
'ithrr case your sail would he NOT only
Useless bur an encunloJb"e.- Garrett
l.. Serviss in New York journal.
Carrfctiuo tbs .Iudna