Reaction tests with the group of University students were conducted in
essentially the same way as were the reaction tests with the soldiers.
Details in regard to the method and apparatus employed need not be
repeated. They can be found on pages 274 to 276.
Two new tests were added to the regular reaction determinations. One of
these consisted in taking a record of the number of taps which could be
executed in ten seconds. The reactor was seated before a table on which
was fastened a telegraph key. He held the key between his thumb and first
two fingers, and at a given signal began tapping as rapidly as possible
until told to stop. Each time he tapped he closed an electric circuit.
The current thus made was carried through a marker which indicated on
a smoked paper each make and break at the key. A time line from a rod
vibrating at the rate of once every twentieth of a second was traced on
the smoked paper parallel with the marker record. By a comparison of the
time line with the marker record, it was easy to determine the number of
taps made in ten seconds. At first, the number of taps per second were
counted, but the results showed such uniformity from second to second on
a given day that only the net results for the whole ten seconds are given
in the tables.
[Illustration: W. L. ANDERSON