San Antonio daily light. [volume] (San Antonio, Tex.) 1886-1907, 1895-06-04
TO MEASURE REACTION TIME.
Wonderful Invention by Prof. e. W.
Scripture of Yale University.


Scripture of Yale University.
New Haven Cor. New York Times
One OF the busiest departments
OF Yale university is the psyche
logical department, over which
Prof. f. w. Scripture presides.
Some new invention or apparatus
is developed there every little
while, and the world wonders at
the ingenuity of the device. Prof.
Scripture has given a represent
alive OF the New York Times the
particulars OF an arrangement just
contrived for measuring runners
reaction time. 1t will be OF great
interest to the world OF sports. In
discussing the device, Prof. Scrip
ture said;
Everybody loses time. 1t takes
time to think and time to act. II
somebody touches you with a hot
poker or lighted cigarette a Ger.
tain period of time elapses before
you are able to jerk your hand
away. II some one touches your
hand, it takes time for the impress
sion OF heat TO pass up the sensory
nerve in the arm, through the
spinal cord, into the brain, 1t
takes still more time for the COM
plicated BARN processes to occur.
which finally results in nervous i'm
pulse, which passes down the
motor nerves of the arm through
the muscles and causes them 10
move the hand.
This time which is lost is called
the reaction time. So far we have
considered it only as a physio.
logical matter. Viewed from the
psychological or mental side, this
process consists in feeling an i'm
preston of heat and is willing to
draw the hand away. Let us con-
slider for moment il there We're
no reaction time. If you could
withdraw your hand the instant
anything touched it, hot coal
could be applied TO the skin and
you could feel, and yet there would
be no time for the coal to burn the
skin. The length of the reaction
portant factor. In the runner it
must be made very short. In the
whale it is very convenient that
the time is extremely long. The
sailor can drive his harpOon into
the whale. 1t takes so long for the
impulse to run up and back the
long nerves in the whale that the
sailor has time to get his boat out
Of the way before the whale strikes
with his tail.
ain running sprint races, it is
very important to save even the
fifth Of second. 1t proved by ex-
pertinent that the time which
elapes between the firing of the
starters pistol and the actual start
ing Of the runner is long enough to
Influence the winning OF race.
This the runners reaction time.
The sound strikes the ear, the
nervous impulse goes to the brain,
the brain processes NJ ust occur,and
then the impulse must 60 out to
his legs. The reaction time OF
runner may varyfrom one-sixth to
over ~0ne-third of "a second. The
stopwatches record in fifths of a |
second. So that the quick man
may gain enough from his reac-
ton time to just win the race.
San arrangement for measuring
a runners reaction time down to
the thousandth Of a second, has
been contrived in the Yale labora-
tory. The starters pistol is ar
ranged so that an electric contact
is broken when the pistol goes off. |
A thread is attached to the right |
foot Of the runner. This thread
breaks an electric contract the mo-
ment the runner starts. Each Of
these electric contacts makes a
spark on asmoked cylinder in such
a way that the time which has |
between the first contact |
and the second can be measured"