Chapter CXXIII: Section 44: INDICATING SPEEDS, &c

(_See also p. 100._)

=Indicators= are employed--

To register the entry and exit of workmen to or from a factory;

To register speeds and variation of load, steam pressure, &c., on an
engine;

To register wind pressure, barometric variations--rainfall, sunshine,
&c.;

To register periodical visits of a watchman or other official, and the
hours of such visits;

To register visits to a bank safe.

=2211. Indicator to register the flow of water= by its speed and pressure against a floating ball, which actuates a pencil moving vertically against a paper cylinder which is kept revolving slowly by clockwork.