The San Francisco call., 1896-10-04

In this exquisitely accurate and so to
speak microscopic measurement of feet
ing second there may be very slight
changes in the chronoscope, by reason of
temperature or other climatic conditions.
Even the electric current, which sets the
chronoscope in motion, may dellcately
vary, Notwithstanding the employment of
electro magnets, which are made as nearly
perfect as possible. To correct this there
has been invented what is known as the
control hammer.
The last-named device consists princi-
pally of heavy weight, which, attached
to lever, falls through varying arcs of
circle, accordingly as it is gauged or set.
The control hammer does not really con-
troll, but when IL is attached to the chrouo-
scope it records with unimpeachable accu-
racy. The weight or hammer is raised
through the prescribed arc, and is held up
by an electromagnetic.
When the current is shut off the ham,
mer falls and touches the springs and
here another electric current makes an in
stantaneous record. The exact time which
is required for the falling of the hammer
through definite distance is, of course,
absolutely known. So the central ham,
mer notes all variations in the chrono-
scope and makes that instrument as
nearly perfect for the measurement of in
finiteslmal periods of time as anything Of
human make can we'll be.
The friction of the point on the paper
affects the length of the marks caused by
the tuning fork, but does not change the
speed with which it records in the least.
Applying this scale can be prepared.
The waves of the tuning fork appear upon
the blackened paper like billows traced
out in white scratches. It may be added
that only one make of batteries is used
for starting the chronoscope, it having
is the most constant.
TIE apparatus for producing tones and
fine sub visions of tones is in several
parts. Outwardly it consists of an organ
bellows, operated by treadle, two boxes
of reeds and large funnel-shaped affair.
The treadle can operate all or singly.
The funnel emits the tone which is ordi.
narily described in musical notation as
great c. The two boxes of reeds are fitted
with series of small stops, and on the
front of each of these stops is painted the
number of vibrations per second which
the reeds with which they are connected
respectively make.
There are thirty-two stops to each OF the
boxes One box is known as the tonom-ter
and this subdivides the sounds usually in
cluded in the scope of an octave into
thirty-two sounds. These collectively
embrace all the harmonies included in an
octave. The other box is known as the
overtone apparatus, and gives the over
tones proceeding from the funnel or
trumpet. In addition to the vibrations
the harmonic relations of the tones are
indicated. It will be seen that these tone
making concerns possess startling posi-
bilities in an otherwise entirely quiet
room.
There is one other clockwork device
which merits description. This is the
kymograph. The use of this is to turn
around brass drum at a fixed rate OF
speed. To this brass drum is affixed a
roll of delicately smoked paper. This
paper can be used for holding an auto
matically made record of the beating of
the heart, or of the pulse, or the respira-
ton of the subject who is undergoing in
vestigation. The heart is recorded by the
aid of a pneumatic tube, the pulse by
pressure upon the artery. When the
paper is dipped in ixative like shellac,
the record of all those physical phenomena
which were induced by contrived mental
conditions becomes a permanent history
and can be filed away by itself or with
others as a memorial of this new advance
mept in the inc of physical inquiry into
the human mind.
The University Of California has not yet
provided the rooms necessary for the
laboratory OF experimental psychology in
Berkeley. Mr.. Stratton saws that at least
eight rooms should be provided. These
should be near together. 1t is not neces-
sary that all should be en- suite, but they
ought to be all electrically connected.