Descriptions of the principal changes in the calorimeter and bolometer unit from the WR28 models of a microwave serving as National Bureau of Standards standard for power measurements in the frequency range 50 to 75 GHz.

Conversion card issued by the United States National Bureau of Standards containing conversion information for length, area, mass (weight), volume, and temperature (exact). The front lists "Approximate Conversions to Metric Measures" and includes a continuum of temperatures at the bottom and a centimeter ruler along the right side (to 8 cm.). The back of the card lists "Approximate Conversions from Metric Measures" and includes an inch ruler along the right side (to 3 in.).

Report discussing the case of upper and lower state interaction introduced by a unified theory using a more compact tetradic notation. The general result is then applied to the Stark broadening of hydrogen. The thermal average of the time development operator for upper and lower state interaction is presented. A simple technique for evaluating the Fourier transform of the thermal average has been developed. The final calculations based on the unified theory and on the one-electron theory are compared with measurements in the high and low electron density regime.

From Abstract: "Comparisons with other other intensity measurements in individual spectra indicate that the National Bureau of Standards spectral-line intensities may have average errors of 20 percent, but first of all they provide uniform quantitative values for the seventy chemical elements commonly determined by spectrochemists. These data are presented by element in part I, and all 39000 observed lines are given in order of wavelength in part II."

From Preface: "This new edition of the NBS Tables of Spectral-Line Intensities incorporates three improvements on the original edition of 1961. In the original edition only about 25 000 of the 39 000 lines in the tables had been classified. In the ensuing thirteen years, about 8500 more lines (chiefly rare-earths) have been classified and the new classifications are here incorporated."

From Abstract: "The lattice complex is to the space group what the site is to the point group - an assemblage of symmetry-related equivalent points. The Tables list site sets and lattice complexes in standard and alternate representation. The higher the symmetry of the crystal structures is, the more useful the lattice-complex approach should be on the road to the ultimate goal their classification."

From Abstract: "This is a tutorial Monograph describing various aspects of time and frequency (T/F). Included are chapters relating to elemental concepts of precise time and frequency; basic principles of quartz oscillators and atomic frequency standards; historical review, recent progress, and current status of atomic frequency standards; promising areas for developing future primary frequency standards; relevance of frequency standards to other areas of metrology including a unified standard concept; statistics of T/F data analysis coupled with the theory and construction of the NBS atomic time scale; an overview of T/F dissemination techniques; and the standards of T/F in the USA. The Monograph addresses both the specialist in the field as well as those desiring basic information about time and frequency."

From Introduction: "This is the second in a series of reports concerned with research and development requirements and areas of continuing concern in the computer and information sciences and technologies."