Firefox: Set Mouse Autoscroll, Linux

“AutoScroll” lets you middle-click on a empty area to pan-scroll in any direction by moving mouse.

In Firefox Linux, it's not turned on by default.

To turn on autoscroll:

1. In the URL bar, type about:config, press Enter.
2. In the search box, type “autoscroll”.
3. Double click to toggle general.autoScroll to true.