The objective of this project was to study the effect of small artificial cavities on natural convection from a horizontal surface. Tests were run with Feron 113. Data for heat flux as a function of bulk temperature difference were carefully obtained. These data yielded Nusselt number as a function of Grashof number or Rayleigh number. All of these were then compared with the data obtained by Hiep [Ref. 2]. Experimental results are presented for the heat transfer from horizontal circular disks, with and without artificial cavities. The artificial cavities were found to affect the natural convection heat transfer from a horizontal surface: the heat transfer coefficients increased with the number of cavities.