Abstract
A new approach to experimental investigation of thermal flow field produced along an isothermal plate of finite dimensions in free convection is presented. The experimental procedure is based upon a flow visualization technique developed earlier by author. The contribution of this paper apparently is that a physical grid placed in the light path of a photographic flow visualization system enhances the ability to discern growth of thermal flow field produced due to temperature difference between a body and its surroundings. The results obtained from flow visualization experiment are verified with a correlation predicted by earlier published work.