Vol 7 Iss. 1

As we resume the publication of the "Proceedings of the Mining Institute," we wish in these lines to commemorate the one who was their founder and permanent editor. The significance of the scientific works of E. S. Fedorov is immense. He worked in the following fields of knowledge: crystallography, mineralogy, geometry, petrography, and geology. He wrote over 400 works on various branches of these sciences. A fairly complete list of these works is placed in Volume III of the "Materials for a Biographical Dictionary of Full Members of the Academy of Sciences," Part 2, M-Ya, p. 205.

The article highlights the most significant among the constant errors and points out the importance of this distinction for correctly assessing the accuracy of baseline measurement using the Jäderin apparatus. The main constant error is the error in the given length of the wire. Other errors—those resulting from incorrect temperature correction, slope, or deviation of the wire from the baseline axis—are negligible. The available data show: 1) a decrease in the relative error with an increase in the baseline length for a single wire; 2) good agreement between the results of forward and backward measurements with the same wire, which provides grounds for not seeking any other systematic error beyond the errors in the calibration of the wires. The absence of systematic errors in the measurement process itself constitutes the main advantage of the method of measuring with invar wires of considerable length.

The content of the present article can be divided into two parts: the first is the derivation of a formula (first proposed by the author) for the mean error of the adjusted value of all measured quantities included in the adjustment; the second is a new derivation of the formula for the mean error of a single observation. Using this relationship (see the article), we provide a new, simple derivation of the aforementioned formula, which is important for the theory of least squares.

In the bilateral symmetry of Rugosa corals, what first catches the eye and prompts one to seek an explanation is the external form of the coral—a cone bent like a horn. Neumayr (Die Stämme des Thierreichs) already points to this form as characteristic of the entire Rugosa group. In the explanation I have given of the structure of Rugosa, I proceeded from the fact, which I established for the first time, of the lateral attachment of Rugosa corals, so that in this respect there is some similarity with Bernard's hypothesis. However, I proceeded from the fact of lateral attachment, which I have firmly established—this attachment being primary, and not secondary as in Bernard's view, according to whose hypothesis lateral attachment replaces an initial axial attachment, occurring as if by truncation of the pointed end.

Observations on the forms and character of cross-bedding led me to pose the question of whether they might serve as a criterion for recognizing the genesis of this stratum. The objectives of this work are: 1) to arouse interest and outline a program for detailed and thorough observations on the highly distinctive phenomena of cross-bedding; 2) to indicate an approach to their interpretation (given the current state of our knowledge); and 3) by applying these general considerations to observed specific cases, to raise the question of the possible elucidation of the genesis of the coal-bearing stratum of the Moscow Basin and of continental deposits in general, through the study of the character of stratification.

Based on its geological structure, the Southern Urals can be divided into three parts: western, central, and eastern, extending along the strike. The main objective of this essay is to raise a number of general issues—the division of the Southern Urals, the continental Devonian deposits, the stratigraphic scheme—and to provide a brief characterization of the main facies and horizons of the southwestern Urals. The essay serves as a preface, an introduction to a series of works associated with the five-verst survey of the Urals being conducted by the Geological Committee. These studies are to be broadly expanded over the next five years, and their results will undoubtedly modify and supplement the data presented in this essay.

The mapping of mineral deposits is one of the most important objective methods for their study. This work is devoted to the development of rational mapping methods, treating this issue in general terms. The first impetus for this work was the pressing need for a rationally constructed map of the Altai polymetallic deposits. The necessity of such a map became evident already in the early years of the Geological Committee's research in the Altai, and at that time work was undertaken by both of us in two directions: mapping methodology was developed, and literary, archival, and new unpublished material from the Altai workers of the Geological Committee — necessary for compiling a map of the Altai deposits —was collected. This article is the result of the work carried out in the first direction.

The article provides some theoretical foundations for the technical calculation and critical evaluation of jaw crushers. The general advantages of jaw crushers are high throughput, simplicity of design, low cost, and ease of repair; the disadvantages are the intermittent nature of operation and the presence of large oscillating masses, which generate strong noise during operation and cause vibrations in the factory building. Therefore, the issue of balancing a jaw crusher is very important for practice. Typically, one jaw is fixed, while the other receives oscillations from the drive mechanism. The author examines the design types of jaw crushers, the arrangement and shape of the jaws, and defines the optimal shaft speed, throughput, energy consumption, and other parameters (see the article).