Map of the United States and surrounding areas with time zones marked and labeled in red. Bodies of water are marked, with depth marked by hatchures, as well as state lines and major cities..

Report of the annual conference on weights and measures, hosted by the U.S. National Bureau of Standards in Washington D.C. It includes conference proceedings, a list of attendees, information about committees and officers, and other reports or commentaries discussed at the meetings.

A report containing a table and Mollier chart for ammonia below -60° F.

Report examining the problems of handling liquefied gases and discusses the feasibility of transporting them through piping systems.

Mollier chart of properties of ammonia.

Diagrams and tolerances in inches for different size terminals.

Fundamental principles and techniques used for voltage measurements primarily for frequencies in the upper audio- and radio-frequency ranges and including part of the ultrahigh frequency range.

Report issued by the Bureau of Standards over chemicals used for tanning leather hides. As stated in the introduction: "an investigation was conducted to determine the suitability of sulfite cellulose extracts, derived from the waste liquors discharged from paper pulp mills, for use in tanning hides for the manufacture of leather" (p. 309). This report includes tables, and photographs.

Report issued by the Bureau of Standards over new developments of electrical resistivity in manganin wire coils. The results of the developments are discussed. This report includes tables, illustrations, and photographs.

Report discussing a search conducted for stable, oil-soluble, organic compounds of metals (and other elements) for use in the spectrographic analysis of petroleum products. Compounds having suitable physical properties have been selected as standards. Methods are given for preparation of the compounds and for the spectrographic and chemical analysis of the chosen standards. Procedures are described for the preparation of stable solutions thereof in petroleum oils.

Report discussing the transient magnetic behavior of a paramagnetic substance, after an initial disturbance, considered theoretically for a variety of situations in which the lattice temperature rises as a result of energy flow from the magnetic (electron spin) system. Next, the opposite extreme is considered - that in which the resonant and remaining modes are totally uncoupled. Finally, there is a consideration of the case of spins coupled only to the resonant phonons, which in turn are coupled to a constant temperature bath, whether this be the helium or the remaining modes.

Report reviewing the theoretical methods of optical pyrometry and the application of these methods at the National Bureau of Standards in realizing, maintaining and distributing the International Practical Temperature Scale above 1063 ºC is presented. In the theoretical presentation, the concepts of effective and mean effective wavelengths are introduced, and various equations relating these parameters to each other and other physical quantities are derived. The methods presentation discusses important features of precision visual optical pyrometers, experimental procedures, and results of primary and secondary calibrations of optical pyrometers.

Report presenting a bibliography on atomic transition probabilities. The papers are arranged according to elements and stages of ionization, and the method employed and class of transitions are indicated behind each reference. Only articles on discrete transitions, both permitted and forbidden, are listed. Also included is a supplementary list of papers dealing with transition probabilities from a general point of view, a table showing the availability of numerical material on the individual atoms and ions, and a table of conversion factors.

Report describing a gravimetric hygrometer that serves as the NBS standard instrument for the measurement of the moisture content of gases on an absolute basis in terms of mixing ratio (mass water vapor/ unit mass of dry gas). The National Bureau of Standards and other laboratory reference and working instruments are compared and calibrated with this instrument. The measuring operation involves the absorption of the water vapor from a water vapor-gas mixture by a solid desiccant and the determination of the mass of this water vapor by precision weighing; it also involves the determination of the volume of the associated gas of known density by counting the fillings of two calibrated stainless steel cylinders. The construction and operation of the instrument is described. Discussions of the tests and calibrations of component parts, and of the sources of errors also are included. There is also an analysis of the random and systematic errors effecting the overall accuracy in the determination of mixing ratio.

Report discussing the VLF, ELF propagation in the earth-ionosphere waveguide emphasizing the total field found by summing all modes which contribute appreciably. Solutions are given and calculations are made for a homogeneous isotropic ionosphere, a homogeneous ionosphere with a constant radial magnetic field imposed, and an ionosphere with a magnetic field of arbitrary dip angle.

Report compiling the work done in radio meteorology over the past ten years at the National Bureau of Standards' Central Radio Propagation Laboratory (CRPL). There is an emphasis upon the effects of the lower atmosphere on the propagation of radio waves. The CRPL group has concentrated upon the refraction of radio waves as well as the refractive index structure of the lower atmosphere on both synoptic and climatic scales. Additional chapters on radio-meteorological parameters and the absorption of radio waves by the various constituents of the lower atmosphere.

From Introduction: "The purpose of this report is to present an analysis of time variations in: (1) the phase (relative to a stable phase reference) if a 9414 Mc/s signal transmitted over this path, referred to hereafter as single-path phase data; (2) the phase observed at one receiving antenna relative to that observed at an adjacent antenna, referred to as phase difference data; (3) atmospheric refractivity as recorded by a microwave refractometer located at the Haleakala terminal; (4) the wind velocity at both ends of the path, and (5) surface atmospheric refractivity measured at 5 stations located on or near the path."

From Object and Scope of This Paper: "This paper describes the apparatus and procedures used at the National Bureau of Standards for the measurement of d-c resistance when an accuracy of a few parts in a million is required. The object will be to explain procedures in detail and as simply as possible, with a minimum reference to theory."

From Preface: "A brief description of the method used in compiling these tables and the limitation of coverage are given in the preface to Supplement 1 of the NBS Circular 510. The present volume contains information pertaining to substitution, exchange, and elimination reaction types and extends the material on these types found in NBS Monograph 34, Volume 1. The date on each page gives the year and month to which the literature had been surveyed."

From Introduction: "The data are presented with the idea that an engineer who is making initial calculations on equipment for operation at cryogenic temperatures is more interested in obtaining quickly a definite figure that he in evaluating the experimental data given in several detailed reports on the same material. The graphs and tables presented here, consequently, represent an attempt by the authors to perform evaluation of data which have appeared in the literature and to present the design engineer with the result."

From Preface: "The purpose of this book is to replace, in part, a previous publication of the National Bureau of Standards (Circular 462) with the same title. The scope of the present work has therefore been broadened to include aspects of ionospheric radio propagation which were not treated in earlier publication."

From Introduction: "The present paper contains detailed descriptions of the methods used in calculating both the elastic constants and the statistical parameters. These detailed descriptions have been included for two reasons: (1) To leave no doubt as to the exact procedure, and (2) to act as a guide to other workers who might wish to make similar determinations."

From Purpose: "The specifications and tolerances contained in this Monograph should be of assistance to purchasers of metal capacity standards. The information on methods of calibration and use of these measures should prove valuable to weights and measures officials and those persons in industry who are concerned with measurements of volumes of fluids."

From Abstract: "For about 1500 spectral lines of diatomic molecules observed by coherent radiation techniques, measured frequencies, assigned quantum numbers, and newly computed intensities are given."