The following figures have been corrected:

Fig. 2

The bubble, shown (left) in the upright position and (right) on its side, prevents mixing between the two chambers and is stabilized by a balance of pressure, surface tension, gravity and buoyancy forces

Fig. 2

The bubble, shown (left) in the upright position and (right) on its side, prevents mixing between the two chambers and is stabilized by a balance of pressure, surface tension, gravity and buoyancy forces

Fig. 3

Cross section of small channel showing the bubble dimensions: R, radius; h, length; H, half length

Fig. 3

Cross section of small channel showing the bubble dimensions: R, radius; h, length; H, half length