This project is to construct a convection tank filled with a fluid such as corn syrup whose viscosity is very sensitive to temperature variations. It is to be bounded below by a flat glass surface at constant temperature and bounded above by a thin layer of relatively low viscosity immiscible fluid such as silicon oil or kerosine. Above that layer is a flat glass surface at a constant colder temperature than below. The breadth of the tank is to be at least five times the depth so that many cells with large aspect ratio are possible. It is desired to attain as high a Rayleigh number as possible within the physical limitations of the fluids and tank. With this one can attain up to 20 cm depth of test fluid that will lead to a Rayleigh number in excess of a million. We anticipate that the above configuration will exhibit convection closer to that believed to exist in the mantle, with columnar thermals of hot fluid rising from the bottom boundary layer and with more sheetlike cold thermals descending from the top.
