Evening star., 1932-04-24
Two HeadIights Need.

Two Headlights Need.
Why motor vehicles are required
to have two headlights is ex-
planned in an interesting manner
by Harold G.. Hoffman, commits
sioner of motor vehicles of New
Jersey.
The question is one to which
every motor car owner, or opera
tor, should know the answer, but
the number of "one-eyed" auto
mobiles that can be counted upon
the highways of the Nation any
night would indicate that many
never have considered the reason
for this requirement.
This query might prof1tably be
made part of mental examina-
ton given applicants for drivers
permits. 1t almost certainly will
be in the future if such tests are
designed to cover more than the
mere letter of the motor vehicle
and traffic laws.
There is an excellent reason for
two lights on the front of motor
cars. And, it is not that two
lights are essential to give ade-
Quate illumination. The single
light of the railroad locomotive
is vastly more powerful than the
strongest motor vehicle head
lamps.
But, unlike the locomotive, the
highway vehicle does not travel a
fixed path. It's lighting equip
ment must serve the function OF
outlining the form and width OF
the vehicle. That is the reason
for the requirement; if it did not
exist so imperatively, the automo-
bile manufacturer could produce
a single light of sufficient power.
However, it does not follow that
because the purpose OF two lights
is to outline the form Of the au-
tomobile, one lamp will give ade-
uuate illumination. 1t might be
done, but it is not. Because he
must equip his car with two
lamps, the manufacturer divides
the burden of adequate illumina-
ton between them.
Proper Perspective.
The motor car owners of the
Nation really need to get a pro-
per perspective on the whole
question of headlighting.
1t is very easy for any motorist
to see his own headlights and to
tell whether or not they glare
dangerously. ALI that he needs
to do is to walk out IS feet ahead
of his car and glance at the lamps,
This Is not the most precise meth
cd of checking the adjustment,
but it is the quickest way for the
average automobile owner to tell
whether or not his lights are
seriously out of aim and focus.
N, standing erect, he is blinded
by the lights at this distance, it is
a Bure sign that approaching
drivers are similarly afflicted by
their maladjusted beam. In max
ing this kind of test, the motorist
should have the lights set bright"
in the older cars and on the upper
beam in those with dual beam
lamps.
AS little effort as is involved in
an experiment of this character,
there Is a still simpler one that
will indicate with fair accuracy
whether ones headlights need
adjustment. The motorist does
not even need to leave the drivers
seat to make this test. All that
is necessary is to note where the
beam of his cars lights strikes
the machine travelling just in
front of him.
Height of Rays.
At a distance of 25 feet, the
rays should be no higher on the
rear of the other machine than
the distance from the road sur
face to the center of ones lamps.
Lights that reflect from the rear
window of the car ahead obvious
ly are out of adjustment.
There still Is another simple
way OF noting the effect of ones
own headlights. In passing a
vehicle coming from the opposite
direction, your lights are incor-
rectly adjusted if they shine in
such a way as to make the other
driver visible at a distance of so
feet.
Headlights should be checked
periodically by the most precise
method available, but the atten-
tive, thoughtful driver can make
simple and comparatively effec-