electrostatic Instruments before 1800 It is the fundamental premise of instrument-science that a device for detecting or measuring a physical quantity can be based on any phenomenon associated with that physical quantity.
"The Earliest Electromagnetic Instruments"
Robert A. Chipman
We have to be content, therefore, to disguise our present ignorance by the use of some descriptive term, such as electric strain, electrostatic strain or ether strain, to describe the directed condition of the space around a body in a state of electrification which is produced by electric force.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
This is equivalent to an electric force of about 500 electrostatic units.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming