Abstract: Due to the progresses of space technology, the manufacture of high quality materials such as the semi-conductors or metal (Pr<<1) in space is coming true. It is difficult to observe the flow structure and temperature distribution in the liquid bridge of opaque molten semi-conductor or metal. Therefore, in present time, the experiments of thermocapil-lary convection are mainly conducted in the liquid bridge with transparent medium (Pr>1) such as silicon oil. The purpose of this paper is to study whether the ...