WINDOWS, BATHS, AND SOLAR-ENERGY IN THE ROMAN-EMPIRE

Windows were a prominent feature of Roman architecture and were especi ally important in the magnificent bath buildings of the Roman Empire. A growing literature attests to the Romans' use of solar energy in hea ting these large buildings. Edwin Thatcher claimed in 1956 that the wi ndows in such baths did not require glazing. In this paper I refute th is claim, drawing on modern ideas about solar energy, heat transfer, h uman comfort, and the effect of glazed windows to analyze one room in the Forum Baths at Ostia This analysis is compared with that of Thatch er for the same room. In window size and solar orientation, this room is typical of Roman baths in many parts of the empire. The solar scien ce and technology of today is thus compared with that of the Romans an d with that of Thatcher's day.