In this medium we can at any place produce a state called electric displacement or ether strain as we can produce compression or rarefaction in air; and, just as the latter changes are said to be created by mechanical force, so the former is said to be due to electric force.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
Towards morning, the painful rarefaction of the air diminished.
"Plotting in Pirate Seas"
Francis Rolt-Wheeler
As the bar moves to the right it compresses the layer of air to its right and that compression is immediately communicated to the layer of air to the right; as the bar moves back and to the left, the pressure on the adjacent air is released and a rarefaction takes place.
"Manhood of Humanity."
Alfred Korzybski