The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1895-04-21

versity, whose psychological subjects
are now given special attention, has
been doing some valuable work with
the new apparatus called the pendu-
lum chronoscope, or the pendulum
timer, designed for recording the time oc-
cupied by the various operations of the
mind. Some of the tests of this instru-
ment. made at recent demonstration by
Professor Scripture, were most interest
ing. Skilled pianoforte players know that
one of the main essentials to a smooth
and artistic performance is the ability to
press any required number of keys exactly
at the same instant. This is much more
difficult than is generally believed, but the
timer will bring the musician nearer to it
than any instrument yet devised. A we'll
known pianist was asked by Professor
Scripture to preside at the piano. He was
told to move both hands at the same time
in pressing the keys. He was quite sure
that he had done so until the reading of
the timer was taken. This showed that
his left hand was fifteen-thousandths OF a
second behind the right. To obtain
this record a telegraph key was put
under each of the performers hands. Con-
nected to these was an apparatus, includ-
ing a large spark coil and two metal re-
cording points which rested on revolving
drum. The drum was covered with
smoked paper. The moment each key
was pressed a spark was made from its
pointer, and the distance between the
sparks was told off in thousandths of
second by a tuning fork adjustment. In a
similar manner the psychologist can ascer-
tain the time occupied by any given effort
throughout the whole domain of mental
life. The operation of the pendulum
ICY Dfo ,n1 fr,C
elaborate series of tests is being made
by Professor Scripture for the purpose
of determining many hitherto unknown
phenomena connected with sight, touch,
etc. The pendulum timer was made under
the supervision of Professor Scripture for
Professor C. B. Bliss, who proposes to pub
lish the results of large number of meas
urements on mental time he is now taking
THE EFFECT OF CoLoRED LIGHT ON
PLANTs.-Although the store of human
knowledge on the subject of the attributes
of colors is gradually growing, and we
have even gone so far as to differentiate
the sounds caused by the falling of ray
of sunshine on cloths of various tints,
comparatively little is yet known of
the physiological effect of color on
human beings. The votaries of the
''blue glass craze" which came into vogue
some years ago, may possibly have been
wiser in their generation than those vino
derided them. Whatever the effect of the
colored light on individuals may finally be
determined to be, its influence on plants
is now unquestionably proved. The use of
glass of green tint has for half century
been one of the peculiar charac-
teristics of the plant houses at Kew
Gardens, near London. In 1889 the
experiment was made of substituting white
glass for green in the east wing
of the tropical Penthouse. The i'm
provement in the growth of the
plants was remarkable. In 1892 portion
of the west wing was also reglazed, and
the new temperate fern house was wholly
glazed with white glass. The result has
been so remarkably beneficial that it has
now been determined to abandon entirely
the future use of green glass.
CoTToNsEED MEAL FOR HUMAN BEINGs.-A
South Carolina physician has discovered q
new use for cottonseed meal. He says that
it is valuable article of human food, and
it is not by any means bad eating. His