The Two-Chamber Flower Pot: A Reservoir Below a Perforated Floor

"This invention consists of a vessel or other arrangement having two chambers, one above the other, separated by a perforated plate, through which passes a tube or tubes perforated below the plate." "The plant being placed in the earth in the chamber A and the water or other fluid being placed in the chamber B, the sides of both chambers A and B and the bottom of B being glazed and impervious to water or other fluid, the water or fluid evaporating passes up through the perforated plate C by evaporation, and supplies the roots of the plant in the chamber A with water or fertilized fluid". "The orifices F and G are kept tightly corked up in dry weather and left open in very rainy weather, so that when too much rain falls into the chamber A it drains through the perforated plate C into the chamber B, and out of chamber B at the opening G, thus preventing the plant drowning out."

Make two reservoir pots from pairs of nested flower pots: the inner one with holes in its floor held a couple of centimetres above water in the outer one. In the first, leave the gap. In the second, thread a cotton cord from the water up through a hole into the soil as a wick. Fill both with the same moist potting soil and the same seedlings. Weigh each pot on the kitchen scale every day at the same time and note the water lost from the reservoir and how the seedlings look. After two weeks compare the two with the notebook.

**William H. Pugh** of Chicago received US 132,178, dated 15 October 1872. He notes the idea can be applied to "large boxes, hot-beds, and gardens". **Honest limits.** In the notebook, vapour brings only a few percent of a plant's daily water while the soil air is moist; the flow grows only as the soil dries out, when the plant is already short. Liquid water carried up by a wick, or by soil touching the reservoir, is not modelled; the experiment compares it. Gap, area, humidity and plant use are examples. Your daily weights are the measurement.