Geothermal heating a total capacity of 15 GW extracted 88 PJ of heat energy for space heating. Global ground-source heat pump capacity is growing by 10% annually. Hot springs have been used for bathing at least since Paleolithic times. The oldest known spa is a stone pool on China's Mount Li built in the Qin dynasty in the 3rd century BC, at the same site where the Huaqing Chi palace was later built. Geothermal energy supplied channeled district heating for baths and houses in Pompeii around 0 AD. In the first century AD, Romans conquered Aquae Sulis in England and used the
Viridia (gens) that translates as "firm, strong, hardy", and "Tertulla", a diminutive of "Tertia", an old feminine praenomen, which was widely used as a surname throughout Roman history. Viridia (gens) The gens Viridia was an obscure plebeian family at ancient Rome. Members of this gens are known only from inscriptions, evidently dating to imperial times. The nomen "Viridius" seems to be derived from the Latin "viridis", green. Since one of the Viridii left a libationary inscription at Aquae Sulis in Britain, some connection with the obscure British deity Viridios has been suggested, but other Viridii are known from different parts of the