Simple Autoscroll for Chrome
More About Simple Autoscroll
With Simple Autoscroll, you simply set how many pixels to scroll at set intervals, press "Go", and start reading! To stop the scrolling, simply click on the extension icon and the scrolling will cease.
Simple as that!
For a smooth scrolling experience, simple input lower values for both pixels and milliseconds. For example scrolling 1 pixel every 30 milliseconds provides a nice, smooth scrolling experience. increasing the millisecond count makes it slower.
Note: Doesn't work on all websites.