The Hipp Chronoscope - continued...

The Hipp Chronoscope, 'model 75'

In 1860, Hipp left the Federal Telegraph Workshop in Bern and founded his own telegraph factory in Neuchâtel. The Fabrique des Télégraphes et Appareils électriques produced telegraphic apparatus, electric clocks, scientific instruments, and accessories of all kinds. Section B of the 1869 trade catalogue from Hipp's factory gives a brief description of the chronoscope listed as item "75." For more extensive information, the catalogue refers to an article published by Adolphe Hirsch (1830 - 1901) director of the Neuchâtel State observatory, in the physiological journal Untersuchungen zur Naturlehre des Menschen und der Thiere in 1865.

In his paper, Adolphe Hirsch reports on chronoscopic experiments concerning the speed of various sense impressions and nervous conduction. Hirsch had conducted these experiments in 1861 with regard to the so-called personal equation, i.e. the problem of individual errors in astronomical observers. To measure the "physiological time" of various test subjects (among them Hipp), he used the chronoscope. In the paper for the Untersuchungen, he gave a detailed description of the Hipp chronoscope.

One main component of the instrument was an escapement ("Fig. I") consisting of a steel lamella f fixed at one side and an escape wheel s with 20 teeth. The lamella made 1000 vibrations per second and controlled the functioning of the clockwork. The characteristic noise of the working instrument could thus be checked against a tuning fork. The train for the hands was separated from the clockwork and had two dials, divided into 100 parts (fig.s III and V). The hand of the lower dial made one turn in ten seconds and indicates 1/10 sec. The hand of the upper dial needed 1/10 sec for one turn, thus indicating 1/1000 sec. An electromagnet at the back of the chronoscope pulled the dials into the running clockwork. A spring threw them out of the clockwork again when the measurement was stopped.

Today, six chronoscopes of model "75" still exist. All these instruments are of the same type and bear the signature "M. Hipp, Neuchâtel, Suisse" and a serial number. Without any visible modification, this version of the Hipp chronoscope was produced from 1860 to 1875.