80

FLUIDITY AND PLASTICITY

raise or lower the mercury reservoirs. When the mercury passes
into the bulb P, contact is formed with a platinum point and an
electrical signal given. At this moment the chronometer is
started. After the elapse of sufficient time, the stop cock B is
closed and thus the current is broken between the two platinum
electrodes at either side of this stop cock, and a signal is given.
The mercury is now allowed to run out through the stop cock C
until the signal is given when the mercury loses connection with
the platinum point in the bulb P. From the weight of this
mercury, the volume of flow is calculated.

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