Thermae would be heated by a log fire before being channelled into the hot bathing rooms. The design of baths is discussed by Vitruvius in "De Architectura". "Thermae, balneae, balineae, balneum" and "balineum" may all be translated as "bath" or "baths", though Latin sources distinguish among these terms. "Balneum" or "balineum", derived from the Greek signifies, in its primary sense, a bath or bathing-vessel, such as most persons of any consequence among the Romans possessed in their own houses, and hence the chamber which contained the bath, which is also the proper translation of the word "balnearium". The diminutive "balneolum" is
Roman Thermae (Varna) to the province of Moesia with a certain degree of local autonomy. The Roman baths of Varna were built towards the end of the 2nd century and remained in use for about a hundred years, till the late 3rd century. Coins of Roman emperor Septimius Severus (r. 193–211) have been discovered among the bath ruins. Much later, in the 14th century, the ruins of the Roman Thermae were the site of craftsmen's workshops. The ruins were first scientifically recognized as an ancient object in 1906 by the Austro-Hungarian researcher E. Kalinka. The site was further researched by Czech-Bulgarian archaeologist brothers