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.
Surface Grinders are machines that can make a surface of a part very flat, very smooth and very parallel to the face of the part that is mounted to the machine. Surface grinders usually have a spinning grinding wheel suspended over a moving bed. The bed moves the part back and forth under the grinding wheel removing an extremely small amount of material at a time, sometimes down to just a ten-thousandth of an inch (o.0001â³) in order to make a precision part.