Several people have asked me if it is possible to use cascading ram pumps to reach higher than one pump can on its own. The way this would work is have a large ram pump that feeds a large amount of water into another smaller pump located uphill. The lower pump would have to supply enough water to keep the top pump working without running the supply tank dry.
I thought this was a good idea for some testing and that is exactly what I have done. Check out this video for the results of the cascading ram pump test.