Measurements were made of the average Nusselt number at a small innerbody situated in an enclosed space, with the innerbody and the bounding wall of the enclosure maintained at different uniform temperatures. Natural convection occurred in the air which occupied the enclosed space. The position of the innerbody within the enclosure was varied parametrically, as was the orientation of the enclosure relative to the gravity field. Both the innerbody and the enclosure were cylinders with length-diameter ratios of unity, and the cylinder-cylinder diameter ratio was 0.2. At low Rayleigh numbers and for narrow gaps between the innerbody and the bounding wall of the enclosure, direct interwall conduction enhanced the innerbody Nusselt number. Aside from this, the Nusselt number was remarkably insensitive to both the position of the innerbody and the orientation of the enclosure. The results were correlated to within ± 6% by the relation Nui= 1.050 Rai0.178.