Abstract
Vertical heat transport by single row convection cells in silicone oil is studied experimentally. Lateral walls of the convection chamber are made transparent so that the number of convection cells is observable by means of alminium powder contaminated in the working fluid. Although various number of cells may develop for each Rayleigh number, the rate of upward heat transport remains the same. There is a definite tendency, however, for the most frequent number of cells to increase with the Rayleigh number. This is in a great contrast to other experimental results (Deardorff and Willis, 1965; Koschmieder, 1966), which remains to be explained.
