The automatic scrolling feature makes it easier to scan through long PDFs, especially reflowed documents. You can scroll through pages without using keystrokes or mouse actions.
To change the scrolling speed to a specific speed, press a number key (9 for fastest, 0 for slowest).
To increase or decrease the scrolling speed, press the Up Arrow or Down Arrow key, depending on the direction of scrolling.
To reverse the direction of scrolling, press the minus sign (-) key.
To jump to the next or previous page, press the Left Arrow or Right Arrow key.