1.0 milliseconds -- cycle time for frequency 1 kHz
1 ms -- duration of light for typical photo flash strobe
2.27 ms -- cycle time for the A above middle C in music (440 Hz). If an electric tuning device for musical instruments generates just one tone, this is probably that tone.
... Portland Basin Museum[?]
Hampshire
Beaulieu Motor Museum[?]
Southsea Museum[?]
Hertfordshire
De Havilland Aircraft Heritage Centre[?], also known a ...