"This is a selected bibliography of books, journal articles and reports published on creep and relaxation in metals and ceramics from 1950 to March 1959. Particular attention has been paid to studies on or applicable to the consideration of creep and relaxation in beryllium oxide. Emphasis has alro been placed on studies of phenomenological materials behavior and high temperature studies."

A method is presented for measuring the average energy of the neutrons from a source. The attenuation of the neutrons by polyethylene is measured by the use of a long counter in good geometry. The attenuation length is a sensitive function of the neutron energy. The average neutron energies from several (o, n) sources have been measured and agree well with values obtained by other techniques.

With the increasing availability of accelerators capable of producing beams of heavy ions it has become useful to know the cross section for a heavy ion to form a compound nucleus by interaction with a target nucleus. The results of calculations based on two simple models are presented here in order to give some idea of the magnitude of this cross section as a function of the energy of the bombarding particle.

This report was prepared at the request of the Subcommittee on Radiochemistry of the Committee on Nuclear Science of the National Research Council as a contribution to a proposed master file on the radiochemistry of all the elements. All known material on the radiochemistry of thorium is included in this report.

Since 1940 ten transuranium elements have been discovered. This lecture describes the history of these elements and the methods used in their discovery.