Reaction Time Apparatus
This finely made timing device was powered by a heavy weight which hung down under the clockwork mechanism. The two dials indicated elapsed time and allowed measurements as fine as 1/1000 second. It used a small ''tuning fork'' escapement which regulated and controlled the speed of the mechanism. The mechanism was controlled by a pair of electromagnets which were mounted on the rear of the main clockwork timing gear box. The device was used to time short elapsed intervals in reation time experiments. It was manufactured by Royer Tavarger & Co., Neufchatel Suisse and carries number 20659.
Stanford White Swinging Reaction Time Apparatus
This reaction timer was "set" by swinging the lever to the far left where it was held in place by a catch. The experimenter released the catch which simultaneously presented a visual stimulus to the subject through the round hole and started the pendulum swinging. When the subject pressed the response key, electromagnets mounted on the swinging pendulum instantaneously clamped it to a curved metal plate and stopped it. The distance that it moved along the calibrated scale indicated the elapsed time. It was manufactured by Stanford White, 300 Broadway, New York., and carries serial number 142.
C. H. Stoelting Dual Pendulum "Vernier Chronoscop" Reaction Timer
This apparatus allowed the time elapsing between two key-pressing responses to be measured. Pressing either of the two black buttons released the corresponding metal disk and a count of the number of swings before they became sinchronized allowed calculation of the elapsed time difference. The pendulums were set to exactly equal lengths by running the metal rod through the holes in each pendulum and adjusting the strings to equal tension. It was manufactured by C. H. Stoelting Co., Chicago, Illinois.
Columbia University Fall Tachistoscope
This device used gravity to cause a metal aperture to fall down across a slit in the stationary plate and expose a visual stimulus. The speed of movement of the falling aperture and therefore the exposure time of the stimulus could be measured by timing the closing of the four electrical contacts which were mounted on the stationary portion of the apparatus. It was manufactured in the machine shop of the Columbia University Psychology Department and carries the engraved words "Columbia University" on its base.
This device used gravity with or without additional spring tension to move a metal aperture down across a slit in the stationary panel and expose a visual stimulus. The exposure was initiated electrically by passing a voltage through the coils of an electromagnet. The subject saw a plain black panel with a window in it and the stimulus was presented through the window.
Spindler and Hoyer Rotating Vertical Drum Kymograph
This clockwork spring driven kymograph rotated the vertical drum at a constant speed. Electrically operated, fluid operated or air operated pens traced physiological and/or behavioral changes on paper which was taped to the drum. It was manufactured by Spindler & Hoyer., Gottingen.
Stoelting Mercury-Dip Contact Metronome Pulse Generator
This metronome can be adjusted to swing back and forth at different rates by sliding the weight up and down the swinging arm. Each time it swings left or right, a contact dips into a pool of mercury and closes an electric circuit producing a string of pulses at variable repetition rates.
Spindler and Hoyer Mercury-Dip Contact Relay
This relay was activated by an external circuit during an experiment. Upon activation, the electromagnets pulled down the armiture which dipped a metal pin into a pool of mercury and closed an electrical circuit. The heavy weight on the far end of the armiture could be used to slow the operation of the relay and therefore introduce a delay into the circuit closure. It was manufactured by Spindler & Hoyer of Gottingen, and imported by Arthur H. Thomas., Philadelphia.
Mercury-Dip Contact Reversing Switch
This switch was used for reversing the polarity of DC voltage circuits in reaction timing setups.
Complex Electrical Switching Apparatus
This complex device has a number of electrical contacts and adjustable springs. It's exact function in the psychological laboratory is not known.