ALBERT

Notes: This article deals in an axiomatic manner with problems of definition, classification, and measurement in the national accounts. It argues that the elementary units which must be classified in national accounting are economic objects (real and financial), rather than transactions. The article defines briefly a set of postulates, and shows that the structure of a simple system of national accounting can be derived from them. There are twenty postulates—certain of them establishing basic categories such as sector, time, economic object, value (price); others establishing relations between categories (for example the notion of ownership); and others describing operations in which economic objects can be involved, such as production, final consumption, change of ownership, and change of debtor and creditor (in the case of financial objects). It is shown that the system of postulates makes it possible to consider a large number of accounting concepts (flows or stocks) as classes (baskets) of real objects (e.g., exports, real capital) or financial objects (e.g., payments, total debt of a sector). These concepts can be defined without reference to prices, although prices are necessary to measure them. Other concepts cannot be defined in this way in this system of postulates, for example value added, foreign balance, saving, net worth. However, it is possible to define magnitudes of the latter type and measure them in terms of value: for example, value added can be defined as the difference between the value of receipts and the value of outlays of a sector. In this way it is possible to establish algebraic relations among the national accounting concepts. (This article is a summary of certain parts of the doctoral thesis of the author, published in Norwegian in 1955.)

Notes: It is only within the last two years that the published United Kingdom accounts have been extended to include sector financial accounts; their use for market analysis is, therefore, still in its infancy.The sectors and sub-sectors distinguished in the financial accounts agree very closely with those recommended by the Working Group on Financial Statistics of the Conference of European Statisticians. A major difference is that in the United Kingdom accounts particular emphasis is placed on the distinction between the public sector and the private sector. For this purpose the public sector consists not only of general government but also includes public corporations (that is, public non-financial corporate enterprises). The classification of assets and liabilities is based on a general list which is also similar to that developed by the Conference of European Statisticians.Because of the large capital formation of public corporations and local authorities, the public sector is normally a substantial borrower from the pirvate sector, although its borrowing requirements fluctuate considerably from quarter to quarter because of the uneven incidence of tax receipts. The personal sector provides about one-third of the total saving of the economy, much of which is in the form of contractual saving—through life assurance and superannuation funds and the repayment of house purchase loans. No direct information is available about transactions in stocks and shares by the personal sector, but it is estimated that the sector is a very large seller of securities and in recent years its sales have amounted to £700 million a year.One factor which is important in the analysis of financial accounts and which is not shown specifically as part of the system is the rate of interest. The proportion of personal saving going into the different forms of short term assets has tended to vary according to the relative rate of interest received. The rate of interest also affects the pattern of borrowing by public authorities.The United Kingdom prepares short term forecasts of national income and of the balance of payments, and also forecasts of the borrowing requirement of the public sector and of the central government in particular. For internal purposes, forecasts are made of the various ways in which the government is expected to finance its borrowing requirement. These forecasts provide a useful framework for considering monetary prospects and are particularly important for showing the relation between the forecasts of the balance of payments and of government borrowing from domestic sources, especially from the banks.

Notes: After a short introduction, the first part of this paper (section 3 through 9) provides an outline of the revisions proposed to the System of National Accounts (SNA) of the United Nations which are now under discussion. These proposals were considered by an expert group at the end of 1964 and were accepted by the Statistical Commission of the United Nations in 1965 as the basis for further work on the extension and revision of the SNA. The aim of the revision is to provide a fully integrated system of accounts and balance sheets in which input-output, flows-of-funds and sector balance sheets are incorporated in a generalised accounting framework. Whereas the real side of the economy has been studied analytically in many countries (input-output analysis, demand analysis and so on) much less experience is available on modelling the financial side of the economy, apart from econometric work on saving behaviour, which is fairly widespread. Accordingly, the second part of the paper (sections 10 through 14) contains a discussion of financial model-building in which a number of possibilities are explored. The final topic discussed (section 15) is demographic accounting, by which is meant a framework for recording and analysing human, as opposed to economic, flows and stocks. The development of such a system arose out of the emphasis placed by the expert group on the integration of demographic and economic information.

Notes: This paper is essentially a summary of the book Measuring the Nation's Wealth (Volume 29, Studies in Income and Wealth, New York: National Bureau of Economic Research, 1964), which is the report of study directed by the author. The purpose o f the study was to assess the problems and possibilities of conducting a national census of real wealth as a basis for continuing wealth and balance sheet estimates for the U.S. economy, by major sector.It is stressed that the balance sheets and wealth estimates should be designed as a consistent part of an integrated system of national income accounts. Thus, valuation (at market prices and/or depreciated replacement costs), sectoring, and type-of-asset detail in the basic data and derived estimates should be compatible with the flow estimates contained in the economic accounts. Consistency of stock and flow estimates facilitates analysis of inter-relationships, and is helpful in the estimation process.It is recommended that in the U.S. asset data by broad categories be collected as part of the recurring economic censuses and other reporting systems, but that detail on fixed reproducible assets (construction and equipment) at cost, by year or period of acquisition, be obtained from a small sample of respondents in each industry. The detail would be useful in its own right, and also permit revaluation of the assets by use of price indexes and depreciation rates to a current depreciated replacement cost basis. Where feasible, respondent estimates of market values would also be obtained.The proposal is thus a compromise between the Japanese 1955 sample survey of assets, and the detailed wealth inventory of the U.S.S.R. which was begun in 1959. Preliminary work is now underway in the U.S. federal statistical agencies to expand collection of asset data, and to prepare comprehensive wealth estimates in the framework of the national income accounts.

Notes: Ľutilisation du SCN actuel pour les besoins de la coopération économique internationale est considérée ci-après à la lumière des expériences accumulées au sein de la Communauté Economique Européenne.Ľexpérience des années récentes prouve que si, dans une première étape, le SCN a pu servir de cadre général ďanalyse économique, ce cadre s'est rapidement révélé insuffisant lorsqu'il s'est agi de confronter des structures et des politiques nationales ou de définir des politiques coordonnées dans les domaines économique, social ou financier. Les travaux menés dans différents domaines ont montré la nécessitéďétendre, de détailler, de modifier et de préciser le système actuel de comptabilité nationale.Une question importante concerne ľintérêt de faire apparaître ou ďéliminer du système comptable les différences institutionnelles existant entre pays. Bien qu'à cet égard ľavis des utilisateurs ne soit pas toujours unanime, ľexpérience plaide en faveur ďun système reflétant pleinement les différences réelles de structure entre pays, mais suffisamment détaillé afin de permettre les regroupements fonctionnels nécessaires à certaines analyses.Ľarticle se termine par un bref rappel des principales critiques adressées au SCN actuel par ceux qui, dans le cadre de la Communauté Economique Européenne, se servent de la comptabilité nationale, critiques auxquelles la révision du SCN apportera, espérons-le, une réponse satisfaisante.

Notes: The author believes that the theoretical controversies relating to the two concepts of production have reached a dead end, and that the answer to these questions must be sought in the results of empirical research. It is to this end that he presents the results which he has arrived at in his computation of Yugoslav national income according to the Yugoslav methodology, which shares the material product concept, and the methodology of the United Nations, which is typical of the enlarged concept of production.In comparing the results of the computations according to the two methodologies, the author concludes that in spite of conceptual differences the deviation of the Yugoslav estimates from the values calculated following the system of the UN is relatively modest (4.2%) if domestic product at factor cost is used. The difference relative to aggregates calculated at market price rises to 13.6%. The author explains these differences by the fact that all the Yugoslav aggregates are computed at market prices, and that services financed by budgetary contributions, which amount to 80% of all services, have found their place in the market prices of material production. He finds that the choice of prices used for calculation has a greater weight for the computation of production than conceptual differences in the methodology of the computations.

Notes: This paper is concerned with the influence of different estimation procedures on the data for real output by industry group of a number of O.E.C.D. countries. The authors have examined the methods and indicators used in preparing sector real output data and have tried to assess the effect of the different methods on the recorded changes of sector real output. The data for real output, employment and productivity are compared for the different sectors and countries. The comparison between sectors lays particular emphasis on the dichotomy between the services and non-service sectors of the economy. In this comparison as well as in inter-country comparison it is seen that the data are influenced to a considerable extent by different methods. The survey of estimation methods also shows the incidence of use of double deflation techniques and other methods in the different countries, and the extent to which quality change, output specification and valuation problems are reflected in the different methods.

Notes: This paper examines differentials in output, employment and productivity across seventeen service industries in the United States from 1939 to 1963. Included are 9 retail trades and 8 services mostly from the personal service group. The industries chosen were those for which it was possible to obtain from available data reasonably comparable measures of output and input for selected years since 1939. Also, they are industries for which it is possible to calculate a measure of real output that is not based on labor input.Sixteen of the industries show positive rates of change of real output per man. Thus there appears to be no basis for assuming that productivity cannot or does not increase in industries providing services. However, the rate of increase for the group as a whole was not as rapid as in manufacturing or in goods production as a whole.The data for the seventeen industries give strong support to the hypothesis of a positive correlation between industry rates of growth and rates of change of productivity. The correlations are of the same order of magnitude as those found by other investigators in studies of manufacturing industries.The coefficient of correlation between growth of output per man and growth of output is .93; between growth of output per man and growth of employment it is .54 for 1939–1963. The comparable coefficients for the 1948–1963 period are .70 and .13.The results also parallel those reported for manufacturing in one other respect, namely, the absence of any correlation between changes in output per man and changes in compensation per man.The paper concludes with a discussion of the problems encountered in measuring changes in real output in these industries and presents some alternative estimates based on different concepts and different sources.

Notes: After an introduction setting out the general state of work on the national accounts in the Middle East the author considers the principal uses of national accounts statistics in less developed countries. The first group of uses discussed is in connexion with the measurement of growth and the making of international comparisons. The author is of the opinion that in many cases the primary statistical series are so weak that the fact they they are combined together into a series called national income or gross domestic product lends to them a significance which they do not really possess. The real problem is to improve the quality of the primary series.A second use of national accounts statistics is in connexion with fiscal and budgetary policy. In the statistically advanced countries this is one of the most important uses but in the less developed countries budgetary policy has not yet reached a level of sophistication which would call for the use of national accounts data. Moreover, the time factor involved in assembling accurate national accounts estimates militates against their effective use for short term forecasting.The author considers that the most important use for national accounts statistics is to provide a framework for development planning. The United Nations system is not altogether appropriate for this purpose. It grew up primarily as a system for recording income flows but in development planning one is concerned equally with commodity flows with a great deal of attention being focussed upon intermediate products. The proposals of the working group of African Statisticians for an adaptation of the S.N.A. to African countries represents a most important advance in this respect.In the final section of the paper the author advocates a broader definition of capital formation to include developmental expenditure which is not properly defined as fixed capital formation. Education expenditure is cited as an example. It is suggested that in the national accounts it would be desirable to operate with gross concepts. However, the growth of the capital stock is obviously important in less developed countries and it is suggested that statistical techniques be devised to measure it directly wherever possible. Finally, attention is drawn to the ambiguities and weaknesses in the concept of residence as used at present in the S.N.A.

Notes: Cet article examine comment les calculateurs modernes servent ou pourraient servir en comptabilité nationale, soit pour ľutilisation des comptes, soit pour leur préparation.Du premier point de vue ľauteur insiste ďabord sur la complexité croissante des comptes nationaux qui rend difficile leur usage à partir de la forme classique de tableaux imprimés et tend à rendre nécessaire leur transcription sous forme de cartes perforées, cequi permettra de faire à la machine un certain nombre de travaux élémentaires sur les comptes.On peut également penser que les calculateurs permettraient des sondages rapides sur certains éléments des comptes en cours de préparation.Enfin, les utilisations des calculateurs électroniques pour ľanalyse des comptes, ľétude des modèles de projection et leur résolution sont bien connues.En ce qui concerne ľutilisation des calculateurs pour la préparation des comptes ľauteur montre que, étant donné le caractère imparfait du système statistique dans de nombreux pays, les comptes économiques des années passées sont en partie préparés àľaide de véritables modèles qui permettent de passer des données de base aux comptes et qui peuvent dans certains cas être résolus àľaide de calculateurs électroniques.Là oùľinformation statistique est meilleure, des éléments des comptes peuvent être calculés directement par agrégation des données élémentaires. On peut donc penser qu'une époque viendra où la plus grande partie des comptes nationaux sera préparée àľaide de machines électroniques à partir des données de base.On peut alors imaginer un monde où les transactions élémentaires seraient enregistrées au moment où elles seraient réalisées, rendant ainsi entièrement automatique la préparation des comptes nationaux. Mais alors les machines pourraient réunir les modèles de préparation et les modèles ďutilisation des comptes. Ľétape intermédiaire que constitue la préparation et la publication des comptes sous la forme actuelle deviendrait alors inutile.

Notes: The paper discusses national balance sheets in the light of the proposals for their inclusion in the revised SNA. The author uses his own estimated national balance sheet of the United Kingdom as a basis for discussing the problems encountered in the compilation of national balance sheets, and the greater part of the paper is concerned with questions of valuation, classification and statistical source material. The concluding section deals briefly with the structure of the national balance sheet of the United Kingdom and compares its structure with that of the national balance sheet of the United States. Provisional national balance sheets of the United Kingdom for each of the five years 1957 to 1961 are presented.

Notes: Both the yearly and the quarterly national accounts of Norway are derived with intensive use of electronic computers, punchcards and magnetic tapes.The introduction of the paper gives a short description of the Norwegian national accounting system. Four aspects are stressed. First, the accounts are built up by the production approach with the main purpose of, on the one hand, showing the domestic product at market prices by industry of origin and, on the other hand, showing a detailed breakdown by categories of expenditure. Second, the main part of the system consists of an input/output matrix of about 1700 commodities, 130 industries, and 150 final demand sectors. The input/output table is thus not made separately but is the main body of the national accounts. Third, this annual input/output table is used as a basis for estimating quarterly accounts. Fourth, an econometric model for analysing and forecasting developed by the Norwegian Central Bureau of Statistics is closely linked to the national accounts.The paper concentrates on how the computers and punchcards are used. It describes how all available information on the supply and use of commodities, prices, etc., is brought together. As far as possible punchcards from the basic statistics are taken over for further processing. As the end result each flow in the national accounts is represented by a punchcard.The paper discusses what has been gained by switching from worksheets to punchcards. There are advantages during the work and there are advantages of having the final results on punchcards.The final sections describe how the punched cards for the yearly accounts data are used as basis for preliminary estimates of quarterly accounts and also in a model for forecasting.

Notes: (1) The primary contribution from the computer's application to the national accounts may well be to erode the line between micro and macro analysis. Key macro totals in the accounts sum individual company reports. The computer permits us to develop distributions of these reports. Such distributions, regularly presented, would permit discovery of the first forerunners of change, would help distinguish, e.g., widespread strength in an export drive or a profits surge, from participation by a few major concerns that dominate the aggregate.(2) The strikingly different parameters in cross section and time series studies (e.g., price elasticity of housing) will in some measure reflect incomparability between the micro data that enter into each. The computer makes possible the use of the wide array of micro data that really underly the accounts to develop consistent analyses of time series (of both aggregates and distributions) and cross section analyses.(3) The inconsistencies now imbedded in the accounts but gilded over by the abilities of the estimators are well-known. Discussions of wage price policy rest on data for wages that have no necessary compatibility with data on profits, etc. But since 1,500 corporations account for at least half of U.S. net income, sales, and investment, the computer can test the consistency of reports made by different units in these firms to different agencies—a process totally out of the question before the computer.(4) The potential that the computer offers for prompt revisions in the accounts; for revisions by systematic rule; for tests of sensitivity of the entire set of accounts to particular tailor-made adjustments, is clear.(5) Company purchase orders and accounts are increasingly recorded on cards or tapes. From these we may derive input-output detail and process detail that are light years better than those now feasible from intermittent survey aggregates.

Notes: It is argued that the conventions of an accounting system, such as the S.N.A., are a matter of convenience. The treatment of education as a current expenditure, instead of as a form of capital formation, derives from the Keynesian system, and is not appropriate for dynamic problems of developing countries, where weaknesses in education are often the main “bottleneck” in the process of development. In such countries, expenditure on education clearly yields its benefits mainly in the longer run. To treat this as a consumption item biases policy in the direction of using financial resources for fixed capital rather than human investment, and may cause aid agencies to penalize countries which expand their educational systems. A similar problem arises on other expenditures such as health, but the case for treating them as investment is not so strong.To treat educational expenditure as part of capital formation logically requires two major changes. First education needs to be removed from private and public consumption, and for this purpose a fairly broad definition of what is education should be used. Secondly, the stock of educational capital should be valued. The valuation problems are, however, severe. Variations in cost components make historic cost of little value as a yardstick, and calculations of future returns are fraught with difficulties. Using replacement costs, which seems the best method, involves the construction of education profiles in physical terms which can then be valued by present or by standardised costs. The depreciation of human capital through mortality and retirement can be allowed for by applying national average rates to these physical profiles.Switching educational expenditure from current to capital accounts involves no serious practical problem. However, although there should logically be an allowance for depreciation on human capital, this is not recommended; single monetary measures of educational stock are not very meaningful, and this would involve changing the definition of “net” aggregates. Development of statistics of educational stocks and flows in physical terms—the beginnings of “demographic accounting” fully integrated with the rest of national accounting—is strongly advocated.

Notes: The now urgent problem in the field is to translate into practice the theoretical agreement, slowly reached over the past two decades, on the need for and feasibility of sectorized national balance sheets.The paper discusses the five main uses of national balance sheets, viz. (1) the study of the relations among assets and liabilities at one point of time in one country, particularly the position of financial institutions; (2) the analysis of changes in one country's financial structure between several balance sheet dates; (3) the comparison of balance sheet structure at one date among two or more countries; (4) the comparison of the financial development of several countries for at least two but usually more numerous balance sheet dates; and (5) the use of selected balance sheet items, e.g., reproducible tangible assets or liquid financial assets, in econometric models.Examples are presented of the first three uses, viz. for (1) an eleven sector balance sheet matrix for the U.S. as of the end of 1962; for (2) an unsectored national balance sheet of the U.S. in 1900, 1912, 1929, 1939, 1945 and 1958; and for (3) a comparison of condensed unsectored national balance sheets for a dozen countries (USA, UK, France, Germany, Belgium, Norway, Italy, Japan, Israel, Mexico, India and the USSR) for a date in the neighborhood of 1960.

Notes: Spurious reflections showing a residual move-out are generally present on both corrected seismic cross-sections and common depth point composites.We propose to determine a space-time filter satisfying the following conditions: to attenuate as much as possible reflections presenting a given move-out, to retain intact reflections whose time gradient is zero (or has a predetermined value), to be applicable efficiently even to a small number of traces, not to amplify random noise unduly.After briefly indicating the design principle of these filters, we shall give the results of their application to the theoretical examples, in order to bring out: the influence of sampling interval and filter length (possibility of achieving efficient filtering using an apparatus with a small number of terms), the effect of filtering on dipping reflections (reduction in amplitude and distortion increasing with the time gradient), the range of reflection move-out that can effectively be filtered with the same apparatus, the disturbing influence of random noise.〈section xml:id="abs1-2"〉〈title type="main"〉RESUMEOn constate généralement, tant sur les films sismiques corrigés que sur les résultats de couverture multiple, la présence de réflexions parasites présentant une courbure résiduelle d'indicatrice.Nous nous sommes proposé de déterminer un opérateur de filtrage spatio-temporel satisfaisant aux conditions suivantes: filtrer le plus possible les réflexions présentant une courbure donnée, conserver intégralement les réflexions dont le gradient temps est nul (ou a une valeur déterminée), pourvoir être appliqué efficacement à un petit nombre de traces, ne pas amplifier outre mesure les bruits inorganicés.Après avoir indiqué brièvement le principe du calcul de ces filtres, nous présenterons les résultats de leur application à des exemples théoriques, afin de mettre en évidence:ľ'influence du pas d'échantillonnage et de la longueur du filtre (possibilityé d'obtenir un filtrage efficace avec un opérateur comportant un petit nombre de termes),ľ'effet du filtrage sur les réflexions pentées (réduction d'amplitude et distorsion croissant avec le gradient temps),ľ'ouverture de ľ'éventail des réflexions courbes que ľ'on peut filtrer efficacement avec un même opérateur,ľ'influence perturbatrice de bruits inorganicés.

Notes: The auto-correlation function of a seismic trace contains information on all the multiple reflection activity present in the trace.The interpretation of this information is facilitated by the arrangement of autocorrelation functions in cross-sectional form, in the manner of a normal record section. This is the concept of the Sectional Auto-Correlogram.Specifically, the Sectional Auto-Correlogram will…Show if the record section does not include significant multiples, thus allowing confident picking of the primary reflections.Show if the record section does include significant multiples, giving their travel times and inclinations (and, under certain circumstances, their reflection coefficients).Indicate by what process the multiples should be treated.Yield an authoritative measure of the success of a multiple-attenuating treatment.Delineate shallow horizons, even those whose primary reflections are too early to be recorded satisfactorily.Give the true travel time of a primary reflector, and the sign of its reflection coefficient.The Sectional Auto-Correlogram allows the study of primary reflectors by consideration of the multiples generated by them, and in this sense may be said to turn multiple reflections to advantage. Thus a primary reflection at a certain time is defined if we find that every reflection on the record is followed by a multiple after this certain time. Alternatively, a primary reflection at a certain time is defined if, after that certain time, we can find a repetition of the entire record.The Sectional Auto-Correlogram also has secondary uses in fault identification, crustal studies and weathering problems.

Notes: The development of optically pumped and monitored “atomic” magnetometers has allowed the application of greater resolution in geomagnetic measurements for exploration purposes. This paper presents a survey of instrumentation in use, the variety of exploration techniques that are being used in practice, and an estimate of their state of development.Alkali metals (rubidium and cesium) and helium have been used as active elements to obtain the magnetic-field dependent Larmor frequency. Each of these instruments is capable of obtaining high resolution data (data with sensitivity numerically smaller than one-tenth gamma). They have been adapted for airborne, land, and marine usage.Such sensitivity has enabled the rapid development of geomagnetic gradiometers, high sensitivity aeromagnetics, diurnally reduced ground surveys, broad-band magneto-telluric surveys, susceptibility measurements, and convenient magnetic search and location techniques. Outlines of each procedure and an example of its application are given.

Notes: The common depth point method of shooting in oil exploration provides a series of seismic traces which yield information about the substrata layers at one location. After normal moveout and static corrections have been applied, the traces are combined by horizontal stacking, or linear multichannel filtering, into a single record in which the primary reflections have been enhanced relative to the multiple reflections and random noise.The criterion used in optimum horizontal stacking is to maximize the signal to noise power ratio, where signal refers to the primary reflection sequence and noise includes the multiple reflections. It is shown when this criterion is equivalent to minimizing the mean square difference between the desired signal (primary reflection sequence) and the weighted horizontally stacked traces.If the seismic traces are combined by multichannel linear filtering, the primary reflection sequence will have undergone some phase and frequency distortion on the resulting record. The signal to noise power ratio then becomes less meaningful a criterion for designing the optimum linear multichannel filter, and the mean square criterion is adopted. In general, however, since more a priori information about the seismic traces is required to design the optimum linear multichannel filter than required for the optimum set of weights of the horizontal stacking process, the former will be an improvement over the latter. It becomes evident that optimum horizontal stacking is a restricted form of linear multichannel filtering.

Notes: Book review in this articleW. L. RUSSELL, Principles of Petroleum Geology, McGraw-Hill Publishing Company

Notes: Formulae of the energy spectrum and autocorrelation function have been derived for magnetic anomalies due to four classes of bodies which can be represented in turn by (a) poles, (b) line of poles, (c) dipoles and (d) line of dipoles. The effects of the depth and dimensions of the magnetized sources on the spectrum and the autocorrelation function have been studied. In the case of the dipole models, the orientation of the polarization vector casts a significant influence on the characteristics of the two functions. In all cases, however, the functions change in size and shape as the inclination and declination of the geomagnetic vector are varied.

Notes: The derivation and application of a new method of geomagnetic deep sounding, that is exploring for underground electrical conductivity anomalies by means of temporal variations of the earth's magnetic field, is presented.The problem is restricted to two dimensions (horizontal and vertical) and for the case of a nearly homogeneous horizontal component of the disturbance vector as compared with the vertical over the area in question.The basis of the method is a relationship between both components of the disturbance vector. The first step is a period analysis of the records and from this the construction of so called “characteristic functions”, one for each station, these functions being determined by the conductivity distribution of the earth's interior. The second step consists of a model interpretation of these functions.The method is applied to simultaneous records from five stations (U. Schmucker, 1959) within the region of the conductivity-anomaly of Northern Germany. A preliminary model of this anomaly is given.

Notes: The screening effect of thin, relatively shallow high-velocity layers often presents considerable problems in seismic exploration. Such layers prevent the greater part of the seismic energy from travelling to greater depths and introduce additional refraction arrivals, confusing the seismogram still further.In order to investigate both the screening and refractive properties of high-velocity layers, scale-model experiments have been made over a wide range of layer-thickness/ wavelength ratios (0.05 〈 d/λ 〈 2) for suitably chosen material contrasts. The results may be summarised as follows.Refraction arrivals from thin layers in the field may be recognised by their relatively rapid amplitude decay. Furthermore, the “echeloning”-effect observed for refraction first arrivals may be due to the presence of a (thin) layered structure. Since the apparent refraction velocity varies with d/λ when d/λ 〈 1, differences between vertical well-log velocities and velocities observed along the surface may be expected, making time/depth conversion using surface velocity data inaccurate.Transmission of elastic energy may be expected, if anywhere, only near the shotpoint, at small geophone offset, and for relatively thin screens (d/λ 〈 0.1). The transmitted signal shape is then independent of the layer thickness. This transmitted energy may be registered either in a reflection set-up with geophones near the shotpoint, or in long-distance refraction work.Three possibilities are offered for overcoming the screening effect of thin high-velocity layers: Use longer-wavelength signalsApply short-spread reflection shootingApply long-distance refraction shootingThe experimental results obtained in scale-model arrangements of such set-ups confirm the potentialities of these methods.

Notes: From travel time observations on a test profile ranging from o to 145 km four main events can be distinguished. They represent reflections and diving waves from various discontinuities within the earth crust. A low-velocity zone of a few kilometres thickness begins at a depth of about 10 km, another one probably at 25 km.For the MohoričIć discontinuity (=MD) a gradient zone with a large velocity gradient instead of a first order interface is postulated in order to explain some irregularities of the travel time curve. Comparisons between the to-time of the MD with the statistical data from Dohr and Liebscher show an excellent correlation.〈section xml:id="abs1-2"〉〈title type="main"〉ZusammenfassungAufgrund von Laufzeitbeobachtungen eines Weitwinkelprofils in der Bayrischen Molasse von o bis 145 km Länge können im wesentlichen vier verschiedene Einsätze unterschieden werden, die sich aus Reflexionen bzw. aus Tauchwellen zusammensetzen. Eine Zone geringerer Geschwindigkeit beginnt bei etwa 10 km Tiefe. eine weitere liegt wahr-scheinlich unterhalb 25 km Tiefe. Von den Unregelmäßigkeiten der Laufzeitkurve der MohorovičIć-Diskontinuität (=MD) wird eine Zone mit einem starken Geschwindigkeits-gradienten anstelle einer “scharfen” Grenzfläche abgeleitet. Vergleiche zwischen der to- Zeit der MD-Reflexionskurve mit den statistischen Untersuchungen von Dohr und Liebscher zeigen eine sehr gute Übereinstimmung.

Notes: This paper gives a report about experiments with the geomagnetic field-balance with ribbon suspension of the FANSELAU-type under extreme climatic conditions. These experiments were carried out by several institutions. The results show that the field balances “H” and “Z” give right records even under extreme conditions.

Notes: The design and construction of hydroelectric works, and more particularly of storage reservoirs and dams, in karst areas pose extremely varied and complex engineering, geological and hydrogeological problems, for the solution of which no widely applied techniques have yet been developed.In addition to conventional geological and hydrogeological methods for the study of karst phenomena, the application of more efficient methods of a primarily geophysical nature is called for. These methods, which provide the best means for solving the complex problems encountered in karst, are steadily gaining acceptance.The Miruše storage reservoir and the Grančarevo dam are the key structures in the Trebišnjica hydroelectric complex and are located in an area of typical Dinaric karst. Many of the engineering, geological and hydrogeological problems connected with their design and construction were solved with the aid of electrical geophysical prospecting methods (especially the resistivity method). The investigations provided data on the depth of karstification (the relief of the base level of karst erosion), the position of intensively karstified and tectonically broken zones, as well as on the general orientation of the process of karstification. All these data were helpful in providing a more accurate insight into the impermeability of the rocks that formed the storage reservoir (in relation to the proposed impounding level); they also enabled the consolidation structures (impervious curtains), aimed at preventing excessive losses due to seepage, to be designed more economically.

Notes: The auto-correlation function of a seismic trace contains information on all the multiple reflection activity present in the trace.The interpretation of this information is facilitated by the arrangement of autocorrelation functions in cross-sectional form, in the manner of a normal record section. This is the concept of the Sectional Auto-Correlogram.Specifically, the Sectional Auto-Correlogram will.Show if the record section does not include significant multiples, thus allowing confident picking of the primary reflections.Show if the record section does include significant multiples, giving their travel times and inclinations (and, under certain circumstances, their reflection coefficients).Indicate by what process the multiples should be treated.Yield an authoritative measure of the success of a multiple-attenuating treatment.Delineate shallow horizons, even those whose primary reflections are too early to be recorded satisfactorily.Give the true travel time of a primary reflector, and the sign of its reflection coefficient.The Sectional Auto-Correlogram allows the study of primary reflectors by consideration of the multiples generated by them, and in this sense may be said to turn multiple reflections to advantage. Thus a primary reflection at a certain time is defined if we find that every reflection on the record is followed by a multiple after this certain time. Alternatively, a primary reflection at a certain time is defined if, after that certain time, we can find a repetition of the entire record.The Sectional Auto-Correlogram also has secondary uses in fault identification, crustal studies and weathering problems.

Notes: The development of optically pumped and monitored “atomic” magnetometers has allowed the application of greater resolution in geomagnetic measurements for exploration purposes. This paper presents a survey of instrumentation in use, the variety of exploration techniques that are being used in practice, and an estimate of their state of development.Alkali metals (rubidium and cesium) and helium have been used as active elements to obtain the magnetic-field dependent Larmor frequency. Each of these instruments is capable of obtaining high resolution data (data with sensitivity numerically smaller than one-tenth gamma). They have been adapted for airborne, land, and marine usage.Such sensitivity has enabled the rapid development of geomagnetic gradiometers, high sensitivity aeromagnetics, diurnally reduced ground surveys, broad-band magneto-telluric surveys, susceptibility measurements, and convenient magnetic search and location techniques. Outlines of each procedure and an example of its application are given.〈section xml:id="abs1-2"〉〈title type="main"〉ResumeEn détection des richesses du sol, “les magnétomètres atomiques” qui fonctionnent selon le principe ?un pompage optique ont permis ?obtenir des mesures plus sensibles. Sont décrits les appareillages actuellement utilisés, les méthodes de mesure différentes, ainsi que la situation technique récente.La génération de la fréquence Larmor qui dépend du champ magnétique s'obtient par les métaux alcalins (le rubidium, le césium) et par ľhélium. Chacun des instruments utilisés fournit des résultats de résolution fine, inférieure au dixième du gamma. Des équipements furent réalisés pour ľutilisation aéroportée, sur navire, ainsi que sur terre.De telles sensibilités élevées ont été rendues possibles grâce aux nouveaux gradio-mètres, aux aéro-magnétomètres extra-sensibles, aux mesures des profils terrestres avec correction diurne, aux investigations magnéto-telluriques large bande, aux mesures de susceptibilityé et aux méthodes pratiques de recherche magnétique.Le sommaire explique les principes à la base et les applications de tous ces proédés.

Notes: Downward continuation of the field in the neighborhood of a singularity of a magnetic anomaly is used to render the anomaly more two-dimensional, to make the bottom of the causal body more remote, and to obtain an auxiliary function, φ (O, z), by means of which the anomaly may be interpreted in terms of an equivalent vertical contact or step model. The concept of “apparent depth” is introduced and used in studying depth extent and susceptibility. The methods are illustrated with theoretical and practical examples.

Notes: Refraction along thin high velocity layers and along basement is investigated in two cases.a) high velocity layer just on the basement.b) high velocity layer higher above.Period and attenuation of refracted waves are given as a function of the layer thickness H. Refracted arrivals along thin high velocity layers are visible at significant distances if the layer thickness is not smaller than A/6, where A is the longitudinal wavelength in high velocity medium. the pseudoperiod is proportional to the layer thickness H. The attenuation at large distance follows an x−n e−k1x law, where n is close to I and R1 is inversely proportional to H.Refracted arrivals along the basement are observable even in the case of thin high velocity layers situated in the overburden; their intensity is smaller and their pseudoperiod larger than when no layer exists in the overburden. The intensity of the basement arrival decreases and the pseudoperiod increases with increasing laer thickness.The pseudoperiod and the attenuation of refracted arrival along high velocity layers and along the basement are also highly dependent on acoustic contrasts.Both arrivals from a high velocity layer and from the basement can be recorded simultaneously, provided the frequency spectrum of the seismic cbain is sufficiently broad. IN all cases layer arrivals show a character very different from basement arrivals.〈section xml:id="abs1-2"〉〈title type="main"〉RESUMELa refraction le long des bancs minces rapides et du socle moins rapide sous-jacent, est etudiee sur modeles dans deux cas:a) banc rapide reposant directement sur le socle;b) banc rapide situe plus haut dans le recouvrement.La period et l'attenuation des ondes rerractees sont donnees en fonction den l'epaisseur H du banc rapide. Les arrivees refractees le long des bancs rapides ne sont pas visibles sur une distance importante si l'espaisseur de ces bancs est inferieure a A/6 A designant la longueur d'onde longitudinale dans le milieu rapide. La pseudoperiode est proportionnelle a l'epaisseur H du banc. L'attenuation a grande distance suit une loi eb x−n e−k1x avec n voisin de l et k1 inversement proportionnel a H.Les arrivees refractees le long du socle sont observables en presence de bancs minces rapides dans le recouvrement, mais avec des internsites plus faibles que dans le cas d'unrecouvrement homogene. La pseudoperiode des impulsions refractees du socle augmente avec l'epaisseur H du banc rapide. L'attenuation en fonction de la distance est superieure a l'attenuation observee pour un recouvrement homogene, et elle croit avec H.La pseudo-periode et l'attenuation des arrivees refractees le long des bancs rapides et des marqueurs sous-jacents sont largement fonction des impedances acoustiques des milieux en presence.Les arrivees d'un banc mince rapide et socle peuvent etre observees simultanement a condition que la chaine d'enregistrement ait un spectre en frequence suffisamment large. On constate dans tous les cas que le caractere des arrivees des bancs est tres different du caractere des arrivees du socle.

Notes: The term “structure”, as used here, includes synclinal and anticlinal folds and folding in general, faults, cross fractures and various conditions associated with intrusions. Structure, both regional and local, has a very important role in emplacement of mineralization. Under certain circumstances which occur fairly commonly, structural conditions are reflected significantly in the trends and intensities apparent on aeromagnetic maps. A number of documented illustrations based on Canadian Shield conditions are discussed. Illustrations are drawn from areas of known geology and from proven mining camps, as well as from loci of recent discoveries. Canadian examples are chosen because of existence and availability of extensive aeromagnetic cover, although it is logical to extend the argument to other shields and indeed to regions of other geological, but similar magnetic character.The importance of aeromagnetics in structural approach to exploration and the correctness of such approach seem to be fully substantiated by results discussed.

Notes: The paper describes a transistorised, portable proton precession magnetometer constructed for surface geophysical prospecting. Constructional and circuit details are furnished. The readout of the instrument is digital. The accuracy of measurement is ± 1 part in 20,000. The maximum gradient of the total field under which a satisfactory measurement can be made is about 1 gamma/cm. The sensing head uses a single coil system with distilled water as the proton sample.

Notes: Book review in this articleJ. L. Worzel, Pendulum Gravity Measurements at Sea, John Wiley & Sons, London and New York, 1965, Price 210 sh.D. S. Parasnis, Mining Geophysics, Elsevier Publishing Company, Amsterdam-London-New York, 1966, XVI + 356 pages, 11 tables, 128 illustr., Price N. fls. 50,–.K. Ya. Kondrat'yev, Radiative Heat Exchange in the Atmosphere, Leningrad, English edition, Pergamon Press.

Notes: A brief review of the existing methods of gravity reduction is given and a new method suitable for use on high speed digital computers is described. The method is based on the formula for the gravitational attraction of a frustum of a cone. The topographic contours are represented by polygons and the x and y coordinates of corners of the polygons constitute the input to the computer. The vertical component of the gravitational attraction is calculated by evaluating the cone formula for a number of vertical sections of the topography. Each vertical section is simplified by adopting a procedure of grouping and averaging for the distant points of the section. The effect of the earth's sphericity is taken into account by lowering the distant points of the sections by amounts determined by the curvature. The computations include the area close to the point at which the attraction is required and may be limited to an area defined by a circle centered at this point. The method is therefore compatible with the conventional zone chart methods.As an illustration of the method the gravitational attraction of Caryn Seamount in the Atlantic Ocean is computed. The total Bouguer correction and the Terrain correction are also computed for an area in northwestern South America and comparisons are made with hand computations by a zone chart method. As an example, for work at sea, the Bouguer corrections for an area near the Island of Mauritius in the Indian Ocean are computed and the effects of sphericity and three-dimensionality are calculated.The gravitational attraction of two-dimensional bodies can be computed in a very similar manner. The attraction of the Puerto Rico Trench model is computed and the results are compared with other methods. The effects of sphericity and assumptions involved in extending the models to infinity are discussed.

Notes: A description of planning, organisation and field procedure of a test profile of 150 km length is given. This profile was laid out as an experiment for a detailed investigation of the velocity–depth–structure of the earth's crust in a selected area. The line was to be shot as a wide angle profile with a common reflection point.

Notes: The region of Graus (Central Spanish Pyrenees) has been surveyed by the conventional seismic reflection method in the years 1963–64.This region is strongly accidented and there are only a few roads of access. Thus a good grid of seismic lines could not be realised. Therefore a seismic survey with completely portable equipment was tried out. For that reason drilling was abandoned.The results seem to show that the method of the air-shots is completely comparable with that of buried shots.

Notes: An ill-defined seismic marker has been identified as the top of the sandstone lower Trias in the “Landes”– small area within the whole Aquitaine region for which the S. N. Repal obtained prospecting licences. Before any drilling was made, this marker was thought to belong to the early saliferous triassic series.The quantitative use of the residual gravity anomaly has made the seismic reflection interpretation easier. This interpretation was found to give excellent results along the coastline where all postulated hypothesis proved true in the bore holes of Contis and St Girons.As a first approximation, it appears that the substratum of the saliferous bed in sub-horizontal and has a fairly steady gravity. The Jurassic and the Cretaceous, both limestones, are prevailing (0,15) in comparison with the argillaceous-saliferous Trias and the early Tertiary which was revealed to us with accuracy through seismic surveys. The use of an approximative linear equation where the gravimetric residue is expressed as a function of the limestone thickness allows a better seismic interpretation.This makes possible a more reliable approach of the structural study of post-triassic deposits. The same holds good for the sandstone substratum which shows on an isochronous map strains due to thickness and velocity changes in the overburden. These facts help us to get a better insight into the origin and formation of salt accumulations in this particular area.

Notes: Book review in this articleBarsukov, Blinova, Vibornyky, Gulin, Pakhnov, Larionov and Kholin, Radioactive Investigations of Oil and Gas Wells, English Translation by Muhlhaus, Pergamon Press, 1965, 300 pp., 140 fig.Stuart R. Kaplan (editor), A Guide to Information Sources in Mining, Minerals and Geosciences, Vol. 2, Interscience Publishers, Division of John Wiley & Sons, New York, London, Sydney, 1965, price 95 s.F. J. Pettijohn and P. E. Potter, Atlas and Glossary of Primary Sedimentary Structures, in English, Spanish, French, German, Springer-Verlag, Berlin, Göttingen, Heidelberg, New York, 1964, 117 plates, XVI, 370 pp., cloth DM 59,–.J. Coulomb and G. Jobert, The Physical Constitution of the Earth, translated by A. E. M. Nairn, Publishers Oliver & Boyd, Edinburgh and London, price: 50 s.G. A. Gamburzew, Grundlagen seismischer Erkundung, German Edition, Leipzig, 1964, pp. 430, 271 fig., price MDN 51,–.

Notes: The common depth point method of shooting in oil exploration provides a series of seismic traces which yield information about the substrata layers at one location. After normal moveout and static corrections have been applied, the traces are combined by horizontal stacking, or linear multichannel filtering, into a single record in which the primary reflections have been enhanced relative to the multiple reflections and random noise.The criterion used in optimum horizontal stacking is to maximize the signal to noise power ratio, where signal refers to the primary reflection sequence and noise includes the multiple reflections. It is shown when this criterion is equivalent to minimizing the mean square difference between the desired signal (primary reflection sequence) and the weighted horizontally stacked traces.If the seismic traces are combined by multichannel linear filtering, the primary reflection sequence will have undergone some phase and frequency distortion on the resulting record. The signal to noise power ratio then becomes less meaningful a criterion for designing the optimum linear multichannel filter, and the mean square criterion is adopted. In general, however, since more a priori information about the seismic traces is required to design the optimum linear multichannel filter than required for the optimum set of weights of the horizontal stacking process, the former will be an improvement over the latter. It becomes evident that optimum horizontal stacking is a restricted form of linear multichannel filtering.

Notes: Downward continuation of the field in the neighborhood of a singularity of a magnetic anomaly is used to render the anomaly more two-dimensional, to make the bottom of the causal body more remote, and to obtain an auxiliary function, φ (O.z), by means of which the anomaly may be interpreted in terms of an equivalent vertical contact or step model. The concept of “apparent depth” is introduced and used in studying depth extent and susceptibility. The methods are illustrated with theoretical and practical examples.

Notes: Refraction along thin high velocity layers and along basement is investigated in two cases.a) high velocity layer just on the basement.b) high velocity layer higher above.Period and attenuation of refracted waves are givers as a function of the layer thickness H. Refracted arrivals along thin high velocity layers are visible at significant distances if the layer thickness is not smaller than A/6, where A is the longitudinal wavelength in high velocity medium. The pseudoperiod is proportional to the layer thickness H. The attenuation at large distance follows an x-ne-k1x law, where n is close to I and k1 is inversely proportional to H.Refracted arrivals along the basement are observable even in the case of thin high velocity layers situated in the overburden; their intensity is smaller and their pseudo-period larger than when no layer exists in the overburden. The intensity of the basement arrival decreases and the pseudoperiod increases with increasing layer thickness.The pseudoperiod and the attenuation of refracted arrivals along high velocity layers and along the basement are also highly dependent on acoustic contrasts.Both arrivals from a high velocity layer and from the basement can be recorded simultaneously, provided the frequency spectrum of the seismic chain is sufficiently broad. In all cases layer arrivals show a character very different from basement arrivals.

Notes: This report gives a description of Fortran II programs for filtering and spectral analysis. All programs are tested.

Notes: In the inductive method of prospecting, information on conductivity and size of conducting ore-bodies located in non-conducting host rocks, can be conveniently obtained by studying amplitude-frequency relation or amplitude-phase relation of their response with the help of suitable Master-curves. Experiments carried out in the laboratory on the scale-model method show these Master-curves to be different depending on the type of primary excitation and the shape of conductor. Cases of sphere, plate and disc in uniform field, field of line source and dipole field have been studied with an Amplitude-Phase Meter specially constructed in the laboratory for this purpose.

Notes: The occurrence of shingling in. long range refraction records often makes the task of the seismic interpreter heavier, especially when several refractors are encountered and the velocity contrasts are small.The explanation of the phenomenon given by the existing literature is examined and the theoretical results are compared with the observed data on field records.In field seismograms shingling must be separated from the effect of geological structures or lateral discontinuities.If an appropriate analysis of shingling is possible, this phenomenon can be related to the type of refracting layer, being a useful tool to a qualitative approach.On the other hand the implications of shingling are examined on the side of the geometrical interpretation

Notes: The knowledge of hydraulic and electric properties of porous media and the relations between them is essential for the quantitative evaluation of electric well logs and the solution of other reservoir engineering problems. The state of the art in this field is not yet satisfying. Theories still show considerable discrepancies with practice due to oversimplified model approaches. Empirical relations are either too coarse, not fully determined, or valid under specific geological and geographical conditions only. This article deals with the development of a general theory of the electric and hydraulic resistance behavior of porous media on the basis of a very general statistical network model. A general solution of the relations between formation factor, permeability, and porosity is presented by means of a rigorous mathematical treatment of two limiting cases of such a network. The solution shows that the product of the formation factor and the permeability can be expressed in the expectation values and the variation coefficients of pore channel cross section and shape factor and by a network factor, that depends on the mesh texture of the network. This network factor is in the range zero to one. It is further shown that the path length increase enters both the electric and the hydraulic tortuosity by its square.

Notes: A simple method of magnetotelluric interpretation is derived using the property that the earth currents flow in horizontal sheets. It is shown that when the depth is taken as two-thirds of the Cagniard's depth of penetration (Cagniard, 1953), the mean resistivity-over the depth is the same as the apparent resistivity of the medium. From a mean resistivity versus depth of penetration plot, resistivity can be easily computed at all depths of the sounding.This method gives satisfactory results in a short time and makes it possible to interpret the soundings over media of several layers. However, the results are inaccurate near maximum and minimum points of the plot as well as in the zone of thin layers.

Notes: The authors propose a method of determining the sedimentary composition of the sea-bottom by studying the variation of the frequency contents of the consecutive multiple reflections between bottom and surface of the sea.

Notes: In a previous paper by the present author a method was developed for direct interpretation of resistivity observations made with a Schlumberger electrode configuration. This method consisted of two steps. The first of these was to derive the kernel function in the integral expression for the apparent resistivity from the observed data; the second step was to derive the resistivity stratification from this kernel function.The first of these two steps depends on the electrode configuration that has been used. In the present paper the above mentioned method is modified so as to make it apply to a Wenner electrode configuration. The procedure is indicated by which the method may be adapted to any other electrode configuration in which the distances between the electrodes are finite.The second step in the interpretation, i.e. the derivation of the resistivity stratification from the kernel function, is independent of the electrode configuration used, and therefore needs no further discussion in the present context.

Notes: A derivation is presented of the variance-covariance matrix of endogenous variables in a linear dynamic system, given the variances and covariances of exogenous variables and disturbances. A general formulation of the stabilization problem for linear systems is proposed, using as a measure for stability a function variances and covariances of the endogenous variables.

Notes: The dominating characteristic of most economic time series is the trend and the basie problem in the theory of trend movements consist in discovering the basie causes of long-term changes in the series. The relevance for the theory of economic growth is the determination of economic growth and the extent to which it can be influenced by economic policy. It is commonly believed that, since national product is perhaps our best measure of economic achievement, we may best denne economic growth as a sustained inerease in aggregate national product or national income. Studies of economic growth almost invariably treat longterm change in the national product as the most basic index of national economic achievement and associate other variables with it as causes and effeets. Whereas the theory of trend movements helps to explain the rising movement of certain economic variables; it also determines the influence of such factors as population growth. Perhaps it also creates a better foundation for the analysis of economic dynamics. Abramovitz (1959) has emphasized the need for empirical studies that can give meaning to secular changes in the rate of growth of national product or national income.

Notes: In this paper, the expected return-variance of return hypothesis of investment behavior is applied to the problem ot the wealth-holder's choice of the maturity distributions of his assets and liabilities. It is assumed that the only asset forms available to the wealth-holder are bonds homogeneous in all respects except: the dates on which they promise with certainty to pay their face values plus interest in a single lump sum. Bonds are assumed to be available from a continuous spectrm of maturities in infinitely divisible denominations. The wealth-holder is assuined, in addition, to make risky forecasts of the future level of interest rates.Under these assumptions, the wealth-holder's networth is a random variable with given mean and variance. Expected net-worth and its variance are shown to be functions of a set of moments describing the distributions by maturity date of the wealth-holder assets and liabilities, i. e., the wealth-holder views the maturity distributions of his assets and liabilities as statistical frequency functions capable of being described by a set of statistical moments. These moments are then treated as the wealth-holder's decision variables to be adjusted to maximize a utility function over expected net-worth and its variance. Optima 1 values of these moments then describe the optimal maturity profile of the wealth-holder's balance sheet.

Notes: A two-dimensional, passive element electric analog model was used to determine the spatial distribution of natural ground-water recharge in the Santa Cruz River basin of southern Arizona. Existing records were used to draw a ground-water level contour map of the area in its undeveloped condition. The model was made to duplicate these contours by varying inputs from known locations of recharge. Recharge distribution as determined by the model was consistent with previous estimates, but no direct correlation was found with the contributing drainage area.

Notes: The tidal efficiencies of wells tapping the principal artesian aquifer in Glynn County, Georgia decrease with distance from the influencing tidal body and also decrease with well depth. Although the magnitude of water-level fluctuation of these wells is largely dependent upon the distance to a large tidal body, the time of a high or a low water level in the wells is mainly dependent upon the time of a high or a low tide in a small, nearby tidal body. A modified formula for computing tidal efficiency is developed:〈displayedItem type="mathematics" xml:id="mu1" numbered="no"〉〈mediaResource alt="image" href="urn:x-wiley:0017467X:GWAT24:GWAT_24_mu1"/〉 From this formula, tidal efficiency can be calculated rapidly and easily

Notes: The frequency distribution of dissolved-solids content of ground waters in geologically and climatologically homogeneous terrane units commonly approximates a log-normal distribution. A graphic logarithmic transformation is de-scribed which permits rapid calculation of approximate values for the mean, standard deviation, and coefficient of variation. Statistical parameters calculated by this method show good agreement with known physical conditions in the terranes studied and are precise enough for use as a mea-sure of variability of quality of ground waters for national planning purposes.

Notes: Photogeologic study has been useful in the location of ground-water sources in the state of Sao Paulo, Brazil, and could be important to the investigation of water resources in other areas.Until 1963, it was believed that large areas of the state were unsuited for the location of ground-water wells (as in pre-Devonian crystalline formations) and others weregenerally considered too hazardous (Paleozoic and Tertiary: sandstone lenses in shales). Since that time, when aerial photographs of the whole state became available, the authorhas verified an earlier hypothesis of his own that there are actually very few areas in the state which do not have suitable locations for water wells, and that photogeology is a most valuable method of prospecting.The water sources are parts of highly developed fault/ fracture systems which are identifiable on aerial photo-graphs, at least in this warm humid climate with dry season. Over the fractures the rocks are deeply decomposed, the debris are removed in the rainy season, and existence of water in the dry season promotes higher and denser vegeta-tion along aquiferous fractures, which usually are located in deep straight-line valleys. Even where competent beds are overlain by more than 100 m of unconsolidated strata, many discontinuous nets of parallel straight-line segments are detectable probably because all fractures are really faults with significant throw.To be most effective, the method requires stereoscopic study of areas having dimensions on the order of 10 × 10 km. The selection of locations for drilling should be sup-ported by analyses of the dip of fracture planes (hade) and by other geological-geophysical methods, especially by subsoil electrical resistivity surveying.

Notes: The purpose of this paper is to stimulate additional interest in the hydrogeologic aspects of the International Hydrological Decade (IHD) program and to urge the full cooperation and participation of hydrogeologists in the research and educational activities of the Decade. The IHD, 1965–74, will strengthen the scientific base for water use and conservation, stimulate education and training in hydrology, and improve the ability of developing and developed countries alike to cope with their water resources problems. UNESCO provides an international intergovernmental umbrella and the Secretariat for IHD. More than 90 Member States of UNESCO are participating in IHD and a majority of these have established National Committees for IHD.The UNESCO/IHD program will consist primarily of activities of participating countries themselves, catalyzed, coordinated, and supplemented by international intergovern-mental agencies and scientific associations. Activities of Member States of UNESCO include: collection of basic data through data analysis and applied hydrology; applied and basic research; continental and global water balances and the global hydrological cycle; establishment of hydrological networks and the development of technical competence; fundamental research; definition of principal hydrological features of countries such as precipitation, discharge of water, sediment and dissolved load, evapotranspiration, distribution of tritium in precipitation, surface and ground waters; experimental basin studies to provide insight on the interplay of environmental and hydrological parameters in a broad range of geological, climatic, and ecological conditions; distribution of water in the atmosphere, in lakes and rivers, underground, in permanent ice and snow and permafrost; studies of the rate at which water moves through the hydrologic cycle; use of orbiting satellites and remote sensing instruments for measuring phenomena in the atmosphere and at the Earth's surface and for relaying observational data; organization of egional advanced training and study courses and hydrological institutes; exchange of teams of experts, exchange of professors and research scientists; and organization of symposia and regional seminars.The US/IHD program focuses on the following five major objectives: (1) large-scale balances of water and water-borne material studies; (2) hydrological performance of river, lake, and ground-water basin systems studies; (3) studies of specific hydrological processes and their variations in time, and improvement of methods and techniques; (4) education and training; and (5) services providing coordination and administration support. These objectives provide a framework within which the scientific and engineering community can contribute to IHD. A provisional US/IHD program statement identified, among others, the following hydrogeologic activities: estimation of ground-water discharge to the sea, effects of variations in piezometric head on land subsidence, hydrology in limestone areas, radionuclide tracer studies, chemical behavior of ground water, and dispersion in moving ground water.Hydrogeologists are urged to submit proposals concerning activities for possible inclusion in the US/IHD program. The following seven criteria guide the formulation and inclusion of activities in the US/IHD program by the U. S. National Committee for IHD: (1) the activity is sufficiently fundamental or aimed at results so useful that it will interest all hydrologists; (2) the activity requires joint or coordinated work in two or more countries; (3) the activity concerns a problem whose solution and verification would be improved by work in two or more countries; (4) the activity concerns continental, hemispheric, or global phenomena or processes; (5) the activity requires action in international areas such as polar regions, international waters, and multi-national basins; (6) the activity involves the hydrologic use of earth-orbiting satellites; and (7) the activity involves intercountry exchange or visits of personnel (in some instances, the exchange or visit itself may be the main item of interest). Proposals may be of projects already in progress, for expansion or modification of on-going projects, or for new work. Proposals may be submitted as contributions, requiring no financial aid from or through the IHD; for endorsement by IHD as an aid in obtaining financial aid elsewhere; or, when funds become available, as IHD projects receiving financial assistance from the IHD. Further information may be obtained from: U. S. Na-tional Committee for the International Hydrological Decade, National Academy of Sciences, 2101 Constitution Avenue, N. W., Washington, D. C. 20418.

Notes: A type-curve method for determining anisotropy of unconfined aquifers, developed from electric analog simulation, is applied to drawdowns observed near, a well pumping from a glacial outwash aquifer at Piketon, Ohio. The coefficient of vertical permeability, P z'averaged 365 gpd per square foot. Computed drawdown for the pumped well, based on this value, differed by only a small amount from the observed drawdown. The coefficient of storage, determined from type curves for an image well system, averaged 0.20, typical of unconfined aquifers. Application of the method required a thorough knowledge of geohydrologic controls operating at the test site.

Notes: Criteria and factors are considered which affect the design of a Hele-Shaw viscous flow model for use in ground- water studies. Procedures and construction techniques for assembling such a model are outlined. Some of the advantages and drawbacks in using a viscous flow model are discussed, Three examples are used to demonstrate the use of the model

Notes: A nuclear (atomic) explosive, detonated at suitable depth below the land surface, appears to offer substantial advantages and economies as a tool in the development and management of water, under certain special hydrologic situations. It is appropriate, therefore, that we seek to understand not only the potentials, but also the limitations of such a detonation. This paper is a first, small step toward that end.Greatly over-simplified, what does an underground nuclear detonation do that it can become a tool of water development and management? Consider first a detonation at a depth sufficiently great that none of the products vent to the atmosphere. Minimum depth for such “containment,” in feet, is close to: 〈displayedItem type="mathematics" xml:id="m1"〉1〈mediaResource alt="image" href="urn:x-wiley:0017467X:GWAT13:GWAT_13_m1"/〉in which W = explosive energy, in kilotons.

Notes: In this short paper, selected water quality problems and the research efforts aimed at their solution supported under P. L. 88–379 (the Water Resources Research Act of 1964) at State Water Research Centers are presented. The water quality problems and associated research efforts presented are not necessarily of high priority with respect to the national needs for water quality knowledge; rather, the problems and research discussed are presented as typical of local or regional situations and as examples of the awareness of State Water Resources Research Centers to the local or regional needs for improving water quality management.Selected water quality problems associated with urban- ization, modern agriculture, industry, recreation, and natural environments are discussed with respect to the needs for new knowledge leading to improved management of water resources. Selected Water Resources Research Centers' projects with the objectives of discovering some of that new knowledge are discussed with respect to the research approach adopted by the investigators.

Notes: Maximum yields from minimum aquifers can be accomplished only by strict adherence to best known practice procedures while following the three necessary steps to well completion. These steps are well design, well construction and well development.In well design good practice begins with an accurate log and the obtaining and careful testing of formation samples. From such data, optimum depth, diameters, screen settings, and gravel pack gradations for expected yields can be selected.Well construction should incorporate equipment suited for the kind of formation, size of well, and depth to be drilled. It should be operated by competent and reliable personnel capable of faithfully maintaining all specifications and finishing in a reasonable time, with a well in which all measurements shown on the log are correct.Development techniques which are appropriate for the well, aquifer, and drilling equipment should be used, al-though it appears the high velocity horizontal jetting tool, used in conjunction with chemicals and regulated pumping, offers the most promise.

Notes: The nature and extent of movement of ABS (alkylben-zenesulfonate) and other sewage components through natural soils were studied in the laboratory and in the field north of Denver, Colorado. Small amounts of ABS and bacteria pass through soils and reach the zone of saturation, where they move laterally down-gradient several thousand feet. Total dissolved solids show little fluctuation during such movement, possibly because extracted solutes are replaced by other solutes leached from the soils during water infiltration.In laboratory studies Denver sewage-plant effluent was filtered through packed columns of 8 types of soils. ABS was not significantly removed by most of the soils; how-ever, muck, greensand marl, and residual basalt soil ini-tially removed up to 94 percent of the ABS. Some ABS was removed only after development of bacterial slime on the soils; subsequent infiltration caused leaching of the slime and its adsorbed ABS and other constituents. All soils initially removed about 90 percent of the bacteria within a few feet of travel, but a small percentage passed through the soil. Bacterial clogging occurred quickly in the fine soils but only in modest amounts in the coarse sand, even after three months of flow.Field studies included analyses of river and irrigation water contaminated from a sewage-plant effluent, and well water from selected sites down-gradient between unlined irrigation ditches and the river. Concentrations of ABS and bacteria were significantly reduced during infiltration of irrigation ditch water to the water table. As noted in the laboratory the concentrations of both of these contaminants can be reduced through soil filtering action. In addition there may be some dilution of the infiltrate by the ground water. Dissolved solids showed practically no change between the ditches and the wells.

Notes: The economic importance of the public enterprises has been established on the basis of the following criteria: Own capital, personnel employed, gross added value and various factors giving rise to appreciation.This survey is of a purely preliminary nature, since, in actual fact, given the present situation of the published data, it has not so far been possible to arrive at more precise figures, taking enterprise by enterprise according to a systematic plan.Moreover, it would have been desirable to fill out the above-mentioned criteria by data concerning turnover and investment, As the data collected in the course of this study are so extremely fragmentary, we have been obliged to exclude any statement concerning these two factors.