chronoscope

The clock used for exact work is likely to be the Hipp chronoscope, which gives on its dials indications of time intervals in thousandths of a second.

IC, interrupted circuits; CC, chronoscope circuit; X, key for making stimulus circuit and breaking chronoscope circuit; B, stimulus battery; S, string from reaction key to animal.

Besides, I had read articles about the chronoscope, the plethysmograph, the sphygmograph, and others of the new psychological instruments.

As soon as the point touched the animal the chronoscope circuit was broken by the raising of the upper arm of the key.

The stimulus key, X, was a simple device by which the chronoscope circuit, c, c, was broken at the instant the stimulus circuit, s, c, was made.