Water rises in capillary tubes to a height which is inversely proportional to the inner diameter of the tube. The apparatus at the left below at Kenyon College is only six inches high. Some blue ink in the water helps to make the thin threads of water visible.

   The apparatus at Middlebury College on the right is conserably taller, and is missing one of its tubes. It may be designed to show that the height of a barometer depends on the bore of the tubing.