the name "Babylonia" has generally been replaced by the more accurate term Sumer or Sumero-Akkadian in more recent writing, referring to the pre-Assyro-Babylonian Mesopotamian civilization. Babylonian culture Art and architecture In Babylonia, an abundance of clay, and lack of stone, led to greater use of mudbrick; Babylonian, Sumerian and Assyrian temples were massive structures of crude brick which were supported by buttresses, the rain being carried off by drains. One such drain at Ur was made of lead. The use of brick led to the early development of the pilaster and column, and of frescoes and enameled tiles. The walls were brilliantly coloured, and sometimes plated with zinc or gold, as well as with tiles. Painted terracotta cones for torches were also embedded in the plaster. In Babylonia, in place of the relief, there was greater use of three-dimensional figures—the earliest examples being the Statues of Gudea, that are realistic if somewhat clumsy. The paucity of stone in Babylonia made every pebble precious, and led to a high perfection in the art of gem-cutting. Astronomy Tablets dating back to the Old Babylonian period document the application of mathematics to the variation in the length of daylight over a solar year. Centuries of Babylonian observations of celestial phenomena are recorded in the series of cuneiform script tablets known as the 'Enūma Anu Enlil'. The oldest significant astronomical text that we possess is Tablet 63 of 'Enūma Anu Enlil', the Venus tablet of Ammi-Saduqa, which lists the first and last visible risings of Venus over a period of about 21 years and is the earliest evidence that the phenomena of a planet were recognized as periodic. The oldest rectangular astrolabe dates back to Babylonia c. 1100 BC. The MUL.APIN, contains catalogues of stars and constellations as well as schemes for predicting heliacal risings and the settings of the planets, lengths of daylight measured by a water clock, gnomon, shadows, and intercalations. The Babylonian GU text arranges stars in 'strings' that lie along declination circles and thus measure right-ascensions or time-intervals, and also employs the stars of the zenith, which are also separated by given right-ascensional differences. Medicine Medical diagnosis and prognosis The oldest Babylonian (i.e., Akkadian) texts on medicine date back to the First Babylonian dynasty in the first half of the 2nd millennium BC although the earliest medical prescriptions appear in Sumerian during the Third Dynasty of Ur period. The most