The flow rate of water through the sand varies between the two cylinders, even though it is the same material, a medium sand. It is a time lapse video, sped up by 10X. In fact, the flow rate varies as the water level changes in each cylinder. This demonstrates Darcy's law, which states that the volume flow rate depends on hydraulic head gradient, hydraulic conductivity of the substrate, and the cross section area of the cylinder. Note that hydraulic conductivity doesn't change in this experiment, just the hydraulic head. These experiments were created for Earth science course at SUNY Oneonta, 2022 by L. Hasbargen.