Experiments have been carried out to observe the motion of an initially station-ary circular bubble in a two-dimensional bed of spherical particles fluidized by air. Theoretical work is given in the preceding paper (part 1) by Murray (1967). The experimental problem is similar to that of Walters & Davidson (1962) who devised a technique for releasing a circular air bubble in a two-dimensional bed of water, but it is made more difficult by the requirement that the stationary void, and any boundary used to maintain it, should here be permeable to the fluidizing gas flow. Two different experimental techniques were used.