Towards a Validated Analysis of Scientific Text Structure

A self-irrigating display rack is provided for potted plants, which comprises a tier of display dishes supported on a reservoir base. The display dishes are mounted in vertically spaced coaxial positions on an upright central tubular member which, in turn, is supported on the base. A pipeline extends upwardly through the interior of the tubular member from the lower end to the upper end thereof coaxially with the tubular member. A pump is mounted in the reservoir base for circulating irrigating water from the reservoir up through the pipeline to the top of the central tubular member. The water from the pipeline is returned to the reservoir through the tubular member. The tubular member is provided with a first set of openings located over each of the dishes, and with a second set of openings located at a predetermined level in each dish. An annular plug is provided in the tubular member coaxially with the pipeline and axially located between each set of openings to divert the water in the tubular member out through the first set of openings to the corresponding dish, the water being returned to the interior of the tubular member through a second set of openings after it has achieved a predetermined level in each of the dishes. A third set of openings is also provided in the tubular member at the bottom of each dish to serve as a drain for the dishes at the end of the irrigation cycle. The size of the third set of openings is small compared with the sizes of the first and second sets of openings.