The maximum scrolling speed in image pixels to pan or scroll per second during autoscroll.

A Long value.  

object.AutoScrollSpeed [= value]

The AutoScrollSpeed Property syntax has these parts:

If the AutoScrollMethod is enabled for automatic pan and scroll and the image to display is larger than the display window, then when the mouse is moved near the display window border will cause the image to be panned or scrolled at a rate based how close the mouse is to the border and on the AutoScrollSpeed.

This facility is independent of the EnableScrollBar property. Valid values are between 20 and 500. The default is 180.

This property sets the maximum speed of scrolling. Scrolling speed is slower initially and slower as the mouse gets away from the border (so long as it is still within the AutoScrollThreshold). Also, at higher values of Magnification the maximum pan/scroll speed is reduced, so that the image does not whip by too fast.