Evening star. [volume] (Washington, D.C.) 1854-1972, 1927-03-15
BY MAJ. III. o. ID. SEGRAVE.

Imagine a full-groWn whale, roaring
like four airplanes hurting across the
1andS Of Florida at more than twice
The maximum speed of the Twentieth
Century Limited, and you have some
conception of what it will look like
when l open up the two engines of
the colossal projectile of concentrated
dynamic energy which we cali a car
for want of a more adequate descrip-
ton. What can describe an automo-
bile, built at cost of 100000, capable
of developing 1000 horsepower at
2,200 revolutions per minute from two
12-cylinder engines?
This monster-for monster it is
among it's kinds to take part in the
greatest motoring experiment the
world ever has seen, to be held on a
25-mile stretch of sand at Daytona
Beach, Fla, this month. At that time
shall drive this car in an attempt to
find out once and for all the fastest
speed at which it is possible to travel
on land.
All the experience of two decades of
motoring, all the knowledge and skill
of the finest mechanical and theoreti-
cal brains of three countries are con-
centrated in that car. The most ia
nous men of the automobile world
have summoned all their energies and
cunning to wrest from nature the
great secret that she holds from them.
1t is their last word.
Nature Sets Speed Limit.
Speed, more speed, still more speed
for 20 years racing motorists have
fought for it and have not been salts
fed. Record has succeeded record,
triumph has followed triumph, but
now mans precarious ventures in ter
rife speed are nearing the point
where the laws of nature will say
finally, Thus far and no farther"
For there is limit to the speed at
which man can travel on land. And
the time has come to explore and
chart these farthest boundaries of the
realms of speed. Great mathemati-
clans and theorists tell US these boun-
daries must exist, just as they told us
of the existence of the North and
South Poles before explorers went to
find them. 1t it for the racing motor
list to go out and discover the poles of
speed When he has found them he
will be satisfied.
That is the problem that l have to
face, but before say how l propose to
tackle it let me explain simply how 1t
is that we know that there must be a
limit to the speed which can be trav'
eled on land.
1t is not a question Of mechanical
engineering; it is a question of the ele'
ments and of the laws of nature. The
higher the speed of moving body
travelling over land, the less attention
il PAYS to the laws of gravity and the
more it becomes obedient to the laws
of aerostatics. When you are rush
ing through the air at very high
speeds of, say, 200 miles per hour, you
are putting yourself in practically the
same position as if you were sitting
quite still in a -mile-an-hour hurri
cane-and every one knows what thai
means.
Terrific Forces Exerted.
There is not only the difficulty Of
head-on wind resistance, which, OF
course, becomes more like a brick
| wall the faster you go. There is also
| the difficulty that the wind presses
down on the nose of the car with tire
mendous force, tending to drive the
| front wheels harder and harder into
| the ground, # not actually to turn the
car head over heels over its front
axle. To make this worse, the vino
rushing over the tail Of the car creates
a vacuum which tends to lift the tai
off the ground Apart from assisting
| the car to turn head over heels, this
has the additional effect of reducing
the tractive adhesion of the wheels tc
| the ground, and so of making 1t i'm
possible to go any faster
| Naturally, to overcome these diff
| culties the designer has TO compro
mise. To balance the downward pusf
on the nose and the upward pull or
the tail he has to put more weight II
tie tail. We have found in practice
that the only way of doing this is t
so shape the tail that the wind canno
rush over it so easily. But, of course
we have to pay for this compromis'
by having increased wind resistance
and in consequence less speed.
And we should have TO pay in los
of speed for any other conceivable
wav of overcoming this difficulty.
IT is hard for those who have no
travelled at high speeds to imagine thi
difficulty, so let me give few figures
Wind Tunnel Tests Made.
For months we have been expert
menting 10 find the best compromis
I'm body shapes. This has been don
nv means OF models. In the grea
| aeronautical laboratories of Vickers
at Weybridge, England, little mode
bodies have been placed in wind tun
nels, through which high speed cul
rents Of air, laden with chalk pan
ticles, have been passed. Photograph
have been taken Of the currents O
air and chalk particles, and 1t ha
been possible to reproduce exactl
what would happen to each model
4 200 miles an hour. What has bee
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