The Washington herald., 1916-06-18
MOTOR SPEEDS
DEPEND ON TIRE
Act as Check on Faster En-
gines-Power transmits
sion a Problem.

Efficiency. about which We hear so much
these days, is nothing more than speed
! 1t is doing OF something better than IL
has ever been done before. This hustling
up of the very-day things of the busi-
ness world is a necessity, II we are TO
keep up with the procession In our
pleasures. The idea of speed has be-
/ come a part OF most every form of sport.
There is hardly any limit to which man
will not go to either do something or
witness his fellow man do something in
short space of time. Public favor is
bestowed upon speed and from the earli-
est days IL has been the cusum to
DDS of locomotion.
Today the automobile is the head OF the
list in earthly methods of fast locomo-
ton. There is but one thing that has
it beat and that is the aeroplane, but
( contests Of this nature are of slight in
terest to the average run of individuals
( because they cannot see for themselves
just what is going on.
In twenty years the rate Of travel for
motor cars has increased from twenty
miles an hour TO more than hundred
miles for sustained speed and to better
than one hundred and forty on short
spurts. These rates OF travel have been
shown only in the last two years and
limit of speed for a motor car?
I,sOO Miles Per Hour Limit.
Theoretically It is 1900 miles per hour,
at which rate according to Lord Kelvin
the authority on this question, the fric-
ton OF the atmosphere will ignite the
speeding body But this question OF burn
ing up the car will not cause the de-
signers much worry. Speedway courses
today are fast enough to care for any
rate Of speed that a car may be driven.
and when they become too slow, it is
an easy matter to make the change t.
something that is suitable.
What will be the ultimate motor for
excessive high speed? The aeronautical
motor seems to loom up strongest today.
II Is Just as dependable as the automo-
lbile motor. in fact. more so. Then there
is the possibility of the internal COM
bustion turbine which is somewhat re-
mote. though still within the realm Of
possibilities.
1t would be a very poor compliment tc
the engineers of the future II they could
not find some way to conserve at least q
portion Of the IS per cent of heat that is
wasted through the exhaust and water
jacket.
Accidents due to the failure OF partf
are becoming annually more rare-they
are decreasing as speed increases. Los;
Of control at enormous speeds, due tc
sudden dersngement OF the human mech
anism controlling the car. conceivably
can be counterscted by the employment
of automatic brakes and steering mechan-
ism which would keep the car on IT.
course until it came to standstill. In
closing the driver will remove him Who'll
!, ly from the effects Of air pressure anc
permit him to concentrate upon the con
| troll of his car
The internal resistance Of the car-ir
other words, friction-is not In itself
serious obstacle to ultimate speed. 1t II
readily calculable and its elimination q!
factor is dependent merely upon th'
provision OF sufficient power to overcome
it and still have the additional energ!
] needed to drive the car.
Air Remittance Problem
, More serious than any Of the problems
referred to is that OF air resistance. Ever
this. however. is not as bad as It Nigh
be. despite the fact that It increases a!
the cube OF the speed In the first place
the pilng up of resistance means simply
the augmcntinS Of the power of the motto
, sufficiently to overcome that resistance
In the second place, It seems that It il
. possible to considerably reduce the pro
: jected area OF a racing car and SO brin!
4 down the air resistance. That part o
the car which establishes contact will
- the ground-which receives all the powe
and transmits all the resistance-the tire
is seemingly a more critical factor wher
2 enormous speeds are concerned than any
other of which we are at present cog
infant.
1t has been ascertaned by means o
carefully conducted investigations thai
: the best tire that can be built. carrying
a perfectly balanced car. running on az
= ideally favorable surface. subjected to M
side sway and no added load due to tn.
centrifugal force of the car as 1t woulC
he called upon to resist in running OF
n steep banking. will stand a speed OF fou
: miles a minute for a distance OF half
mile. That Is to say, it would run TO
/ T.5 seconds at the rate OF 24O miles al
hour.
Tire Limit Low.
n 1t is perfectly obvious. however. tina
such conditions are neither more nor les
o than impossible TO present comprehen
e sion and that the practical limit OF tn
T best tires we know how to build is very
r considerably less-so much less. in fact
S that the speeds of today are often quit
e as close to the limit as is permissible
taking into consideration the possibilitie
of failure due to causes which cannot b.
foreseen. or If foreseen. cannot be fore
: stalled.
The responsibility which rests upon tn,
tire is enormous. 1t must carry tn
T weight of the car, and this is a continu
: ally varying quantity because Of periodi
I spring surging induced by inequalities
however slight, OF the track surface, an
because of the stresses, having the efrec
of weight, piled up by centrifugal fore
e when the car swings up on the tracl
S banking. 1t must resist the terrific lat
l. eral stresses that are incidental to sud
8 den changes of direction and to sid
y sway. 1t must stand the tremendous fric
ton due to slipping when the Traction