Athenian cultural dominance continued throughout the Roman period, and the buildings added to the Agora reflect the educational role of the city, a role that ended only with the closing of the pagan philosophical schools by the Christian emperor Justinian in A.D. 529.
Bearing, in machine construction, a connector (usually a support) that permits the connected members to rotate or to move in a straight line relative to one another. Often one of the members is fixed, and the bearing acts as a support for the moving member. Most bearings support rotating shafts against either transverse (radial) or thrust (axial) loads.
TYPES OF MECHANICAL MACHINE. A machine is a contrivance or mechanism by means of which a force, applied at one part of the machine, is transmitted to another part, in order to secure mechanical advantage for some particular purpose. - used for raising a load by means of a smaller applied force.