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This paper will serve to acquaint the reader with general descriptive information about the Bay Area Rapid Transit District's electrical power distribution facilities serving its transit system. The paper describes the systems supplying power to both the fixed facilities and the traction vehicles but concentrates on the latter. Emphasis is placed on features that provide reliability and continuity of service.

The material-energy balance developed in this study has been used successfully to match performance and to forecast production for the Wairakei geothermal field of New Zealand. The equations should be applicable to other geothermal fluid reservoirs, provided the assumptions used are realistic. Introduction The basic study from which this paper was prepared was started as the result of the growing need throughout the world for increasing quantities of energy in all forms. Quite obviously, natural forms of energy that are readily available at low development cost are those in greatest demand. The underdeveloped countries - and particularly those having little or no petroleum resources - are the countries in which the most interest is being shown in the newer energy sources. One of the least expensive energy sources is natural geothermal steam. Although this form of energy has been recognized for centuries, it has been only during the past 20 years that serious efforts have been made to harness it. Natural geothermal steam energy in Italy, New Zealand, Mexico, Japan, and California is now being produced through wells to drive turbines and generate electricity. Further, active exploration for natural geothermal steam is being conducted in Hawaii, Fiji, Taiwan, Chile, Russia, Greece, and Katanga. It is surprising to find that most geothermal steam exploration is in the "steam seep" stage. That is, surface studies are made and exploratory wells are drilled in the general area of steam seeps. However, in the larger geothermal steam areas, there have been efforts to apply the most modern geological and reservoir engineering principles in order to define the reservoir parameters, particularly those relating to estimates of reserves and future productivity. This paper is concerned with the development of appropriate equations and techniques to facilitate these estimates. Production of natural steam or hot water presents problems different from those experienced in the production of oil and gas. For example, steam or hot water systems may be essentially single-component systems, while hydrocarbon systems are most frequently multicomponent fluid systems. Heat effects are much larger for water than for hydrocarbon systems; and the natural steam production may or may not be isothermal, while production of petroleum reservoirs is considered normally to be isothermal. Petroleum reservoir engineering principles may be applied to natural steam or hot water reservoirs if the inherent differences in the systems are considered. The basic considerations involved in geothermal steam reservoir engineering are: thermodynamics, physical and thermal properties of water, materials and energy balances, fluid influx, and performance matching and predicting. Thermodynamics Fig. 1 is a pressure-temperature diagram for the liquid-vapor region for pure water, showing the critical point and five other points representing possible initial conditions for a geothermal steam reservoir. JPT P. 893ˆ

An all-electronic directional-comparison carrier relay system having a maximum over-all operating time of 1 cycle has been successfully tested both in the laboratory and by staged tests in the field. In order to obtain operating experience, this equipment was placed in temporary service by the Appalachian Electric Power Company to protect a 43-mile 132-kv transmission line between Roanoke and Lynchburg, VA, USA. Permanent installation is planned on the 330-kv system of the American Gas and Electric Company to protect the line between Muskingum and East Lima. This equipment is the result of several years' intensive study and tests to determine the best system of line relaying capable of operating under all conditions in 1 cycle. The expansion in system capacity and the trend to higher line loadings makes it desirable to provide protective relaying equipment which will materially reduce the fringe times of 3 to 4 cycles sometimes - encountered with carrier relaying presently available. Planning studies for higher voltage systems, such as the American Gas and Electric Company 330-kv system, indicated that this development should be completed in time to have such equipment available for these systems. While electronic relays have been used in limited applications in the past, the decision to develop an electronic system for line protection was made only after sufficient study and experience provided assurance that the degree of reliability required for such applications could be obtained. In this paper and three companion papers will be presented system considerations leading to the requirement for maximum relay times of 1 cycle, the reasons for the choice of electronic methods to obtain this performance, detailed description of the equipment, the circuitry, and the results of laboratory and field tests.

The purpose of the paper is to describe a method of analysis for taking into account the effect of insulation variability in the determination of breakdown voltages and allowable operating stresses. The method is applicable to systems containing large areas of insulation, or large numbers of units of insulation in parallel. General equations are derived, giving the breakdown voltage and number of failures to be expected, in terms of two parameters; the mean breakdown voltage and the variability of the insulation, both of which are determined from tests made on samples. It is shown how the results may be applied to the special case of electric power cables, for comparing the relative merits of different cables, and for determining the safety factor required to take account of the inherent variability and consequent unreliability of the insulation. The necessity of considering the variability as well as the so-called strength of insulation is emphasized, and its importance brought out in terms of allowable operating stresses and failures. A graphical method of analysis is described, which makes use of probability paper, changing the probability scale from ``per cent'' to ``failures per hundred miles per year'' in the case of cables. Predictions of theory are compared with the results of practise, using results from experiments made to determine the effect of electrode area on breakdown voltage. Good agreement is shown between the two.

The paper records the development of the generation of d.c. power in aircraft by windmill- and engine-driven generators, from its inception to the present day. The developments prior to the last decade are covered only very briefly. Features of generator design which have called for special consideration, or have been the subject of failure, are discussed. Sections are devoted to the choice of speed range, brush wear at high altitude, systems of ventilation, design of end-frames, and bearing failure. Some mention is made of generators designed for power supply to radio equipment, as distinct from general power services. These generators, which include high-voltage d.c. machines and high-frequency a.c. machines, have been combined with low-voltage d.c. machines, both in tandem and with a common magnet system. The latter part of the paper deals with voltage regulation, which is inseparable from the preceding part, in so far as generator design is influenced by the system adopted; self-regulating generators of various types have been used from time to time in the past. The scope does not permit more than brief mention of the design of the several types of regulator which have been used, including Tirrill and carbon-pile types. The paper shows how the control of the system voltage has been conditioned by the inclusion of an accumulator, and how it has not been possible to devise a system which gives the constant line voltage required for current-using devices, and, at the same time, permits of adequate control of accumulator charging current. Systems of paralleling, and their effect on line voltage, are also described. The electrical equipment of lighter-than-air craft is not included in this paper.

This paper discusses superconductivity and the related Meissner effect in relation to electric power generators. Both effects have been suggested for use in improving electrical devices through reduction of friction and other losses, weight, and/or volume. The study described in this paper is analytic and preliminary in nature and without test data, but indicates that large superconductive power generators offer a good potential for future application.

the past decade there has been a decided trend toward municipal ownership of public utilities, including water works as well as electric power plants. The reasons for the trend are not within the province of this paper, but they are probably centered around the control of rates and the service provided, along with the popularity and pride of municipal ownership. But is it not true that there is now an accelerating tendency to discredit municipal ownership because of business policies of municipalities, especially with reference to the prevalent inability of those in charge of the administration of water works to fix or maintain water rates and service charges adequate to maintain and operate their plants on a business basis? The purpose of this paper is to point out some of the elements of this situation and to raise a few questions in the hope that it will lead to a wholesome discussion of the problem, leaning toward legislation wThich will be to the interest of the public and the water works profession.

This paper develops an approach to the selection of an electric power system and the prime internal power source for a short range missile. Every conference has many papers on the subject of power sources for missiles. They cover such items as batteries, ram air turbines, hot gas driven turbines, and such possible power sources as thermionic, thermoelectric, solar cells. Each of the different sources has a particular field of appropriate application and many of the fields overlap. Papers on the choice of application of these items to power systems are very few. It is primarily the function of the engineer to apply the knowledge and the devices available in order to create an efficient overall operating system.

It is the purpose of this paper to deal especially with the employment of electric power, derived from hydroelectric systems of distribution, for the operation of textile mills. It is impossible in a paper of this kind to go very fully into detail, and no attempt will be made to discuss the forms of drives, kind of motors or, in fact, any other technical details, since any one of the more important ones would require a special paper to do it justice.

This paper presents a brief outline of the various solid-state energy conversion concepts currently under development by the Air Force. Much of the paper will be on the developments in solar cells and thermoelectrics with only a brief look at piezoelectrics, pyroelectrics, ferroelectrics, the Nernst effect and nuclear photon conversion. These conversion concepts are discussed from the stand-point of present capabilities to satisfy aerospace vehicle electrical power needs together with the author's estimates of possible performance if the concepts are completely developed. The energy sources considered are solar, nuclear, chemical and acoustic with emphasis on solar and nuclear. Research and development is being accomplished in the areas of solid-state energy conversion today because these materials and conversion mechanisms are most nearly ideal for unattended operation in space. That is: they are relatively static (no moving parts); are non-volatile exceptat high temperatures; are reasonably resistant to the space environment; and generally have long lifetime possibilities. The long range objective of the applied research programs in these areas is to acquire the technology for obtaining reliable, highly efficient, long lifetime, light weight, and low cost energy conversion systems for aerospace vehicles. The lifetime requirements are for essentially unattended operation for two years by 1965 and for five to ten years by 1970. Generally high watts/lb, reliability, and long lifetime are the primary objectives, and efficiency and cost are of lesser importance.

This paper outlines the development of superconducting d.c. machines at I.R.D. where most of the work to date has been undertaken. Particular emphasis will be placed upon the industrial applications for these machines and the paper contains illustrations of the superconducting marine propulsion systems now under construction. The object of the presentation is to demonstrate that superconducting d.c. machines are now available for industrial application after a relatively short period of development. The paper also indicates the substantial advantages to be gained from the successful development of superconducting a.c. generators. The work which is necessary before these machines may be put into production will be discussed by consideration of the principal problem areas. Finally, conclusions are drawn on the present status of superconducting machines and the changing attitudes in industry towards this new technology.

Since the treatment of the general field concept seems to be missing in the literature, and since methods of field ex ploration and of simulation are scattered in a great number of domestic as well as foreign papers, this paper presents, first, a brief survey on fields and on methods of their analy sis and simulation, and then reports on the state of the art in the area of simulation of electrostatic fields by means of a conductive-sheet analog or electrolytic tank.Although the paper has been written primarily with the needs of electric power engineering in mind, the treatment of the subject has been held as interdiscipli nary as possible. The paper will thus be useful also to those working in aerodynamics, elastic stress analysis, heat transfer, astronomy, acoustics, atomic physics, and ma terial sciences. Furthermore, for the electrical engineer, it may be helpful to know that electrical problems sometimes may be solved more easily or more conveniently by the use of nonelectrical methods.In the specialized section on the application of the electrolytic tank and the conductive-sheet analog to the solution of electrostatic field problems, little-known as well as new techniques are discussed, such as (1) plotting of infinite fields on a double analog, (2) determining of force lines or surfaces by means of the dual analog, (3) simulation of areas of different dielectric constants and of continuously variable dielectric constants by means of jellified dielectrics, (4) plotting of areas of low current density by the use of consecutive field mapping, (5) the possibility of plotting fields with rotational symmetry on isotropically conducting sheets and graphically transpos ing the map so obtained, and (6) solution of distributed source problems.A comparison of advantages, disadvantages, and limita tions of the electrolytic tank method and the conductive sheet analog is also presented.Finally, an appeal is made for teaching and use of field analog methods for future developments.

A station having several unique features, including an outdoor oil-filled metal-clad 22-kv switchgear for main generator bus is referred to in this paper. The station forms an important link in a large and intricate transmission and distribution system. This paper is part of a symposium on electric power switching at modern large steam-electric generating plants.

Discussion of a paper by C. M. Gilt published in the December 1933 issue, p. 868–75, and presented for oral discussion at the electric power switching discussion of the winter convention, New York, N. Y., Jan. 23, 1934. Other discussions of this paper were published in the March 1934 issue, p. 456–61.

The electrical power control and conditioning subsystem developed under NASA* Contract NASl-4479 represents an integrated, operational design for the Manned Orbital Research Laboratory (MORL) to support 6 men in space for 5 years. The power conditioning systems discussed in recent engineering papers have generally been planned for unmanned craft or were for optimizations of specific electrical loads of modest demand levels, and used conventional battery, solar cell/battery, or fuel cell energy sources. Therefore, an advanced design to supply a greater (by an order-of-magnitude) electrical demand from a radioisotope-dynamic generator drive system, and which meets manned spacecraft design criteria, represents a significant and unique contribution to aerospace electrical design. This paper identifies and discusses (1) the unique electrical design criteria and constraints associated with the radioisotope Brayton cycle drive system, (2) the tradeoff considerations which were necessary to optimize the total system with respect to speed, frequency, and efficiency, (3) the rationale for the selection of the alternator and the frequency converters, and (4) the distribution system design criteria which were established to assure flexibility, efficiency, maintainability, and safe emergency operations. The control system concept and its integration with the energy storage subsystems will also be discussed.

The first article of this series was published in issue N.° 162 of «Informes de la Construcción», under the title «Salto de Miranda». The present article deals with the work of excavating the gallery. Modern practice requires that to do this type of work successfully the auxiliary material should be most carefully studied beforehand. N.° 164 of the this magazine has included a paper entitled «Recent progress in the auxiliary material for underground gallery excavation», summarising the most recent type of machinery now available in the market. Since the Grand Coulee Dam was built by the Bureau of Reclamation, where essentially new techniques were introduced, including minimum times for maximum progress, these new procedures and equipment have been generally adopted throughout the world. To this must be added the urgent and increasing demands for electric power, and the vast amounts of money involved in these hydroelectric projects, which explain the rapid adoption of automatic procedures in this kind of work. In this paper the author explains how, using the means available to him, he sought to coordinate the various constructional tasks, to get as near as possible to the most economic working cycle. Underground ventilation is an acute problem, and involves the safety of those working inside the tunnel. The author explains, in simple terms, how the theory of fluids and air circulation can affect the rational and practical solution of providing adequate air supply for the health and comfort of the underground worker. To attain this end, however, a considerable mechanical and economic investment is necessary.En el número 163 de Informes de la Construcción se publicó el primer trabajo de esta serie, con el título de «Salto de Miranda». En éste se trata de la ejecución de la excavación en galería, para cuyo éxito las técnicas modernas exigen un depurado estudio del mater ial auxiliar. En el número 164 apareció también un artículo titulado «Progresos recientes del material auxiliar en la perforación de galerías», en el cual se resumen las máquinas más modernas que se hallan en el mercado. Desde la perforación del Grand Culé por el Bureau of Reclamation de Colorado (Estados Unidos), en la que se introdujo el jumbo por primera vez y los tiempos mínimos para avances máximos, los procedimientos y maquinaria se han generalizado en todo el mundo. Si a esto añadimos los intereses apremiantes de necesidades de energía, la importancia de las sumas invertidas y la influencia del tiempo, apreciaremos en mayor grado el automatismo de estos trabajos. El autor se esfuerza en detallar y resumir cómo, partiendo de los elementos a su disposición, trató de coordinar las distintas labores para aproximarse a un ciclo ideal rentable. La ventilación en subterráneos constituye un agudo problema de seguridad para cuantos trabajan en el subsuelo. Consciente el autor de esta responsabilidad, trata de exponer, vulgarizándola, la forma en que la teoría de fluidos y corrientes puede afectar a una aplicación racional y práctica de aquélla en la aportación del elemento clave: el aire para la respiración y confort del minero. Para asegurarlo se precisa un esfuerzo mecánico y económico importante.

In the application of various types of locomotives to switching service, it is at times quite desirable to have data concerning the energy requirements involved. A convenient figure for expressing such requirements in relation to work done is watt hours per ton-mile. The determination of such a figure involves certain difficulties peculiar to switching service, in that trailing loads and distances moved are continually varying. The electrified Oak Point Yard of the New York, New Haven & Hartford Railroad in New York City offered an excellent opportunity for determining figures of watt hours per ton-mile for different kinds of switching. Accordingly two electric locomotives were equipped with the necessary instruments, and a total of 391/6 hr. of operation was observed and recorded. The paper describes in some detail the entire procedure of the tests and lists in tabulated form the data obtained. Basic figures necessary for calculating watt hours per ton-mile, it was found, could be expanded to give a much broader scope to the results, so that many interesting data became available. Incidentally, the data will permit of even further expansion where certain special figures or factors are desired. Although electric locomotives of different types were used, the results set forth in the paper should be considered without regard to either type. It is hoped that data concerning switching operations on other railroads may become available.

Several high-power communications satellites have been proposed which were based on the availability of an electric power supply which could provide 60 kW for one year (minimum) at the cost of 3000 lb. These were the initial specifications of the dual SNAP-8 nuclear powerplant. Since that time, however, it has become clear that the SNAP-8 will be unable to meet these specifications. The purpose of this paper is to present a conceptual design study for a steam-cycle power supply which provides the required specific weight (around 50 lb/kWe) together with reasonable expactation of obtaining the required one-year minimum lifetime. The proposed cycle is the conventional Rankine steam cycle utilizing superheated turbine-inlet steam at 1200 psi and 1200°F. After removal of residual superheat in a recuperator, the saturated vapor at the turbine exhaust is condensed in a radiator at approximately 400°F and returned by a pump to the energy source. At first glance, it does not appear possible to reject heat at such a low temperature without enormous radiator weights. Indeed, the radiator surface area is considerably larger than that required for the much higher temperature liquid metal or gas cycles. However, the unique combination of using steam at low temperatures permits the utilization of two design features which provide remarkably low radiator weight per unit area in the conventional flat fin-and-tube configuration. First, the high latent heat of the condensing steam allows only small volumetric through-put per kilowatt output, resulting in very small tuve diameters. Since the tubes and headers are the only major parts of the radiator which require meteoroid armor, the total tube and header weight does not become excessive. Second, because of the low temperature, it is permissible to use aluminum as the radiator material. Its high thermal conductivity therefore permits the use of quite thin, large-area fins between the tubes without suffering the conduction loss necessitated by the higher-temperature materials of other systems. Thus the fraction of radiator are occupied by the heavy, aluminum-armored tubes becomes quite small. In the sample design (30 kW) presented in this paper, the combination of small tubes and large fins results in a weight per unit radiating area of less then 0·25 lb/ft 2 of radiating area. The energy source may be either a nuclear reactor, the most favorable configuration of which would be a single-pass coiled-tube design (although more conventional boiler-superheater reactors may be used with little weight penalty), or a solar-powered boiler-superheater. Other cycle components are a conventional turbogenerator, recuperator and pump. The specific weight of the sample (30kW) design is 70lb/kW, but upon scaleup to higher powers, improved turbine efficiency, radiator segmentation, and reduced fractional weight of the energy source and turbine can provide estimated specific weights competitive with systems using other working fluids, with no sacrifice in reliability. With regard to reliability, the use of the conventional, long-operational steam provides not only the benefit of many years of experience, but also the capability of using conventional materials; i.e. stainless steels and aluminum, for all cycle components. In consequence, although development problems will undoubtedly arise, there appear to be no significant state-of-the-art improvements required. It therefore appears possible with the proposed steam cycle to provide broadcast satellite power requirements in time to phase in with anticipated communications-system availability.

This paper discusses future electrical power requirements for various possible space missions. Probable time frames are included wherever possible. Three categories of missions are considered: earth orbital operations including communication and weather satellites, manned orbiting laboratories, and scientific satellites; lunar operations in the post-Apollo era; and intrasolar system operations including manned and unmanned planetary missions, solar probes, and out of the ecliptic probes. Power levels necessary to support the missions vary widely; various levels from a fraction of a kilowatt to hundreds of kilowatts are discussed. This paper reaffirms the conclusion reached by a growing number of people that the availability of electrical power may pace future space explorations.

The difficulties and complication associated with the transmission of large blocks of electric power over considerable distances have led, during recent years, to a growing interest in the possible application of direct current at high voltage for this purpose. In spite of the fact that alternating current lends itself readily to generation and potential transformation in bulk, it cannot compete with direct current where transmission on a similar scale is concerned. For this reason direct current can, under certain circumstances, form an economic link between the source of energy supply and the consumer. The paper presents a broad survey of the basic problems involved in generating, transmitting, and transforming electrical energy in the form of super-tension direct current as they appear at the present time, without attempting to add new matter to a subject which is of necessity highly specialized and the province of the transmission engineer. After a brief historical review of the subject has been given in the Introduction, the manifold advantages of high-voltage direct current as a means of power transmission are discussed and the factors limiting its direct generation are investigated. Of the several methods available for converting alternating current to direct current at high voltages, relatively few are at once technically and commercially feasible. A general account is given of those current-converting systems which seem to offer the most promising solution of the transmission problem. The general trend of opinion in favour of the super-tension direct-curent system as reflected in modern transmission projects is explained, and an outline is given of three such schemes of major importance which have been put forward during the last few years. Finally, the paper indicates the course of a rational future development and suggests how the super-tension direct current system of power transmission might with advantage be introduced and further technical data obtained. References to recent literature dealing with the transmission problem are given in a Bibliography.

Static optimization techniques have been used by the electric power industry for several years to solve the problem of economic load allocation. Experience has shown that difficulties frequently arise when these solutions are incorporated in the feedback control of dynamic electric power networks. In a recent paper, economic load allocation was formulated as a dynamic optimal control problem in an effort to overcome the disadvantages of controllers currently used. At the heart of that problem is the area control problem that is treated in detail in this paper. An unusual feature of the area control problem is that it contains kinks. The maximal principle is modified for this situation. Necessary conditions for an optimal controller are obtained for the general case of n generators. The optimal feedback controller is synthesized for the case of two-generator load sharing.

With the advent of gas turbine prime movers for both propulsion and electric power generation, new methods of optimizing thermal efficiency are needed if weight and cost limits are to be achieved by new ship designs without sacrificing operational capability. The balance of primary power generation from fuel and secondary power generation utilizing other energy media must be reviewed. Where once the basic shipboard energy conversion was Bunker C fuel into steam within a large boiler, using steam as the energy medium for all power and heating use, we now have machinery systems that convert fuel into energy at several subsystem levels, i.e. propulsion, electric power, auxiliary steam and so forth. The design challenge for today's machinery system engineer is to optimize thermal recovery from fuel much the same as economizers, etc. that were used in previous steam plant designs. This can be done by making one system dependent upon another for its source of energy. However the design constraint demanded by NAVY combatant ships is that operational flexibility, vulnerability protection and reliability/maintainability/availability goals for each dependent system must be maintained should the primary energy source system fail. This paper presents an engineering approach to generating and evaluating alternative machinery designs within the structure of a set of ship design criteria categories. These categories are defined and examples of machinery system design objectives given. A design process is then proposed which includes determination of energy requirements, identification of alternate energy generation/conversion hardware and verification of adequate energy supply under all operating modes. Discussion is given to the importance of selecting the proper energy medium (fuel, electricity, steam, etc.) for each functional service if energy generation and energy absorption are to be efficiently matched. An evaluation approach is then presented which compares total performance of candidate designs on a system-level basis. Finally, the paper describes two recent ship designs where integration of machinery systems has taken place: the Canadian DDH-280 Class Destroyer and the U.S. Navy DD-963 Class Destroyer. Elements in the “trade-off” studies for these ships are reviewed and design advantages discussed.

This paper discusses the audio frequency noise induced in telephone lines by nearby electric power circuits, particularly when the power and telephone companies employ joint buried construction methods. The electrical protection considerations of this type of construction are not included in this paper. Comparisons are made with the usual aerial type of joint construction. The factors controlling the amount of interference produced by inductive influence are described and evaluated. Recommendations are suggested for limiting this interference to acceptable levels for satisfactory telephone service.

This paper covers an electric ice removal system as applied to a recent experimental airplane. The system is described in detail from the power generators to the ice removal blankets and includes such items as extent of ice protection coverage, construction and installation of ice removal blankets, system electric power requirements, and system control. The paper does not treat the subject of ice protection in any of its theoretical aspects. The complete ice protection system installation is believed to be the first of its kind in this country.

The generation of gaseous effluents as a result of corona activity on EHV transmission lines has been raised as an environmental issue. This paper discusses analytical, laboratory and field measurement work performed by and for the American Electric Power Service Corporation that clearly shows that no environmental problem exists. A companion paper discusses the field measurement program in greater detail.

This paper is not intended to present a case either for or against industrial generation of electric power. It is intended only as a guide to objectivity in determining the true merits of any such proposal. An attempt has been made to point out some of those factors which are too often neglected or insufficiently weighed in economic evaluations of by-product electric power generation projects, and to indicate a method which will, if properly used, automatically avoid any such inaccuracies. The conclusions drawn in this paper are those of the author and not necessarily a statement of the views of his company.

The paper discusses the mode of propagation of energy under steady current conditions, and advances the view that it is only a special case of radio transmission. The electromagnetic theory governs all electrical processes, but, while the high-frequency disturbances of light, or radio-telephony, move in waves which are known to retain their individuality when superposed, the principle of independence does not seem to be applied when the disturbances are of very low frequency so as to approach steady current conditions. In the last case the electromagnetic fluxes are, even nowadays, often regarded as static, and when such fluxes are superposed it is generally assumed that they merge into a single flux. Poynting's theorem of energy flow suggested that the fluxes due to steady currents are moving through the dielectric, but tacitly assumed that the fluxes form a single stream, and that nothing of the nature of reflection occurs when this stream reaches a material surface. It would seem only to harmonize with Maxwell's theory, and with the properties of light, if such streams when incident on matter were to give rise to reflected ones, and therefore to a system of superposed streams. The aim of the paper is to show that such a view is quite consistent with the known distribution of energy to the various parts of the conducting circuit. The mathematical problem is discussed in Part 2 of the paper. The analysis is an example of Heaviside's vector methods. It is necessarily based on assumptions. The physical aspects and the justification of these assumptions are dealt with in Part 1.

Marking a new milestone in the history of the transmission of electric power, the 275 kv system that will transmit power from Boulder Dam to Los Angeles, Calif., embodies many novel engineering features. These features are discussed in this paper. The paper includes not only a description of the line and the terminal equipment and facilities, but also a discussion of the effects of the characteristics of each portion of the system on the performance of the system as a whole. The engineering studies and laboratory research on system stability, corona, high voltage impulses, lightning, conductor vibration, tower stresses, footing uplifts, and other factors are described, and the use of such data in the selection of line voltage conductors, insulation, clamps, lightning protection, towers, and appropriate generating, transforming, and receiving end equipment is shown.