New-York tribune., 1902-01-13
ENGINEERS AND SIGNALS.
DIR. HALLOCK, OF COLUMBIA. GIVES
SOME REASONS WHY THEY
DISREGARD THEM.

Dr. William Hallock OF the department Of
physics in Columbia University. was seen by a
Tribune reporter yesterday afternoon in his
lecture room at Havemeyer Hall about the case
Of Wisker. the engineer OF the White Plains
local, which telescored the rear car OF the South
Norwalk special. He said:
There are a number of possible explanations
OF the engineers conduct. some OF which belong
10 the province Of psychology and others TO that
or physics. II has been suggested that engineers
class subject color blindness. which
prevents the correct reading OF signals. re-
suit Of the constant strain OF watching and the
smoke and cinders. But statistics go TO show
that color blindness is something that is born
with man rather than anything that develops
from abnormal conditions. But in another
sense, color blindness might we'll be the cause
of such accident.
I would explain what I in some such
way as this: AT midday the sun is pure white
TO the eye, loosely speaking. but sunset IL
changes to blood red Now. the sun has not
altered in the twelve hours. The apparent
change of color is due to the fact that NE see
1t at sunset through a medium OF smoke and
dust and atmospheric impurity. Now in the
matter Of signals the ordinary white light would
always have a ruddy glow when seen through
tunnel smoke and foul air, and IL becomes the
problem for the engineer 10 decide whether the
signal is red enough to spell danger and indicate
immediate stop, or whether ii is only the
normal white of safety. which appears red be-
cause Of the clouds of tunnel smoke. The same
optical illusion is possible with a green light 1t.
too, can assume other colors through the haze
So il would be quite possible for both signals 10
indicate normal conditions to the engineer when
in reality they were showing the warning lights
of green and red. The duty. rather, the
qurement of engineer in the tunnel is TO
pick up the message of the lanterns while going
at a clip Of twenty miles an hour.
So much for explanation Of the accident
which belongs to the realm of physics. But II
we grant the hypothesis that the signals could
be clearly seen, the engineers conduct can be
explained in a different way. 1t is possible for
a man TO see physically without seeing psyche
logically. Mental abstraction will cause man
10 see without perceiVing Where one is day
after day doing the same mechanical routine,
any novelty utterly fails to reach the brain
centres and register impression. A man who
walks over the path daily will stumble
over an unexpected obstacle. In manner we
see what we expect 70 Then there is an
other consideration. The engineer might have
seen the signals without being able TO pull the
throttle temporary paralysis results from
sudden intense situation. 1t is parallel or a
woman who stands the track Of an approach
ing car or II is the case of the sparrow charmed
by the snake. From the thing seen TO the re-
sultant action there number OF processes.
and a break in any results in paralysis First.
the impression Is made the rettna OF the
eve; then the optic nerve must communicate
With the brain; then the will sends commands
IN the motor activities. Any stoppage in such
n prOcess results in helpleSSneSS.