Mandy and Natasha have been itching to try out our new U-tube manometer - or more appropriately, womanometer. This is the device that a few lucky folks may remember from their school science labs, which measures pressure directly in fluid-inches, as the difference in height between the fluid levels in the two sides of the U-shaped tube. In our case, we have chosen water, with red food coloring added. We simultaneously measure psi with our usual computer-based pressure sensor, and are aware that one psi = 27.68 inches of water. Our device has a capacity of 98 inches of water, or 3.5 psi.

To begin with, Natasha is elected to climb the ladder and add a few drops of water to calibrate the unit to the zero mark. Then, the two ladies take turns blowing as hard as they can, to see how far they can push down the left column, and raise the right column.