The density & surface tension of two borate containing silicate melts were measured using the sessile drop & pendant drop arrangements under various atmospheres including reducing, partially oxidising & wet air atmospheres. The two main boron containing glasses measured during these experiments were E glass & soft borosilicate glass. Both the E glass & the soft borosilicate glass density decreased as a function of temperature. The temperature coefficient of surface tension for E glass was positive & increased with water content in the atmosphere whereas the overall surface tension as a function of water partial pressure decreased. The soft borosilicate temperature coefficient of surface tension was small & positive & changed little with increasing water in the atmosphere, whereas overall surface tension increased with increasing water content.
