I have not found the word "linkage" used earlier than Sylvester.
In carrying on a stock of a lethal, advantage can be taken of linkage.
Evidently, by exercising this linkage of stimulus and response.
When she was finished Rynason nodded for her to activate the linkage.
There is more than metaphor in such a comparison; there is the linkage of the immanent idea.
By kinematic ...