Abstract: Hydroxy-functionalized polyoxybutylene ether compositions having improved thermal and oxidative stability are prepared by the polymerization of a mixture of C.sub.4 epoxides in the presence of an organic initiator containing hydroxy groups.

Abstract: A microhardness tester comprises a turret capable of holding a plurality of load rod assemblies such that, when the optical objective elements mounted on the turret have been properly aligned with respect to the indenter of one load rod assembly desired to impinge upon a specimen to test for microhardness and it subsequently becomes desirable to use a second load rod assembly to change scales for the testing, it is only necessary to properly align the indenter of the second load rod assembly and not the objective elements with the test specimen. The load rod assembly of the microhardness tester free falls in its testing mode, and a spring is provided for retaining the load rod in a home position spaced away from the test specimen. Thus, the load weights applied to the load rod as carried to the test specimen are not affected by spring load tolerances such that weight calibration can be completed during the weight manufacturing process.