| This timer and impulse counter is in the collection of
the Virginia Military Institute. It was made by the firm of C.H. Stoelting
of Chicago, but is not in the 1912 catalogue in my possession. However,
a very similar device is shown in the 1929 Cenco catalogue.
The apparatus counts electrical impulses produced by an external source. This might be an electromagnetically- driven vibrating bar, the period of which is controlled by clamping a weight at various positions. If this is set to oscillate at a frequency of, say, 10 Hz, the device becomes a clock reading in tenths of seconds.
The Cenco impulse timer sold for $27.50.