ALBERT

Notes: The Ordnance Survey makes extensive use of air survey in its mapping programmes at scales of 1 : 1250, 1 : 2500 and 1 : 10 000. A short history of the development of air survey within the Ordnance Survey leads into a description of current methods including the flying, processing and aerial triangulation tasks as well as the plotting of the maps by instrumental or graphical means.

Notes: A number of proposals have been put forward for the extraction of three dimensional data from a pair of electron microscope photographs taken from different angles. The methods used have, in general, been either point by point analyses or rather inconvenient. This paper shows that an existing photogrammetric plotter of topographic accuracy can, with very simple modification, be converted to give continuous plotting facilities from certain such micrographs.

Notes: The author reminisces upon a career of almost 40 years as a practising surveyor photogrammetrist, both as a Royal Engineer officer and as a director of a commercial survey organisation. The reminiscences include service with the Survey of India, war time operations in the Middle East and South East Asia Command, and commercial surveys of all types in developing countries. Professional service with international surveying and photogrammetric organisations is also mentioned, with particular reference to the fraternal aspects of international photogrammetry.

Notes: An increasing number of applications of photogrammetry are concerned with the analysis of models, constructed to simulate proposed or existing conditions in architecture and engineering. The paper draws attention to some of these projects and reports one example in detail.

Notes: The author describes the photogrammetric equipment in use by the Royal Commission on Historical Monuments (England), the methods used and the work that is being done in architectural recording. The difficulties and the possibilities of future architectural work in the United Kingdom are discussed and the achievements of some other countries in this field are reviewed.

Notes: The article discusses a general classification system applicable to digital ground models (D.G.M.) as used in highway design. Examples of the various categories are given, together with details of some advantages and disadvantages. The place of the D.G.M. in the highway design system is described in conjunction with traditional methods. The relationship between accuracy, density and economy of D.G.M. systems is examined. Finally an experiment is described which investigates the accuracy of various D.G.M. systems; it is being conducted by the Transport and Road Research Laboratory.

Notes: Book reviews in this article:OPTIMIZATION TECHNIQUES IN LENS DESIGN. By T. H. Jamieson.ADJUSTMENT BY LEAST SQUARES IN GEODESY AND PHOTOGRAM-METRY. By R. A. Hirvonen.AERIAL PHOTO-ECOLOGY. By J. A. Howard.PROCEEDINGS OF THE ISP COMMISSION IV SYMPOSIUM 1970. Editor J. Kure.

Notes: The use of aerial photography for hydrographic requirements is discussed, with particular reference to current circulation in an all water area. The paper examines the criteria and limitations imposed by an environment which is alien to normal topographic photogrammetry.

Notes: This paper proposes that salary structures and the development of salaries over time be considered within the framework of the distribution of income over time. In particular, it examines certain salary scales in the U.S. and the progressions of typical individuals’ salaries during the period 1948–1969, in comparison with the percentile distributions of household income in the same period, as reflected by the Current Population Survey of the Bureau of the Census.

Notes: This paper assesses the role of inventive and innovational activity in the growth process of Canada, a country which relies overwhelmingly, some 90 per cent, on the importation of technological advances and operational know-how from abroad. Canada has prospered under this arrangement but at a price. With technology came foreign capital, foreign management and substantial foreign control. To lessen Canada's dependence on foreign know-how, this country has embarked on an expanded R & D programme. But the pay-off from these efforts has been less than expected. To throw a light on the subject, the results of two new surveys are presented: one a sample survey of patents granted, the other an interview survey of large corporations. Questions examined include sources of know-how and technological advances, utilization of inventions and abandonment of innovations, R & D and innovations, domestic and foreign innovations, and the profitability of innovations. Aggregative assessment is supplemented by disaggregative analysis using cross-section and industry data.

Notes: The paper presents forecasting models for (1) the share of competitive imports in the total demand for a commodity group and (2) the level of demand for competitive imports of a commodity group. The two forecasting models are used, respectively, with (1) input-output models which incorporate market share parameters as one vector of coefficients and (2) input-output models which assume imports have been determined autonomously. It is shown that these two types of input-output models can be made workable by prefixing one or other of the import forecasting models to the input-output model. Tests are made of the forecasting ability of the combined models.

Notes: This article is an extension of an earlier article dealing with gains and losses from changes in the terms of trade. The object of the present article is to show how gains and losses in foreign trade are distributed among the branches of domestic industry. To this end, price changes for gross domestic product at factor cost in each of 25 branches of industry over the period 1949–1965, computed where possible by the double deflation method, are compared with the change over the same period in final demand—i.e., consumption plus gross investment.

Notes: This paper develops a method for estimating long-run trends in income growth from the data available on a country's currency stock. The method is applied to nineteenth-centry Brazil. The results indicate that contrary to earlier beliefs, the country as a whole probably experienced only moderate growth in per-capita income during the nineteenth century. The approach may also be useful for other countries where data shortages preclude estimates of national income by conventional methods.

Notes: This paper discusses the relevance of the conventional national accounts systems to the traditional African economy and concludes that they contribute little because they omit certain economic activities and fail to recognise the reciprocity between social and economic activities. Social accounting is thus more relevant. Lack of statistical data may make it necessary to conduct special surveys and in some cases a tribe or village or economic region may be a more useful accounting unit than a nation. A modified system of accounts is suggested, based on the frame work of the four consolidated accounts of the SNA. It provides linkages to many more nonmonetised activities. Other linkages would be provided through supporting tables emphasising social activities and transfers. A system of transactor accounts in matrix form is also suggested. In the case of communities smaller than the nation several external transactor sectors could be included. It is recognised that the problem of evaluation of social activities and a number of economic activities remains to be solved and it is concluded that “time spent” may be the only common unit or value to equate such activities.The final section deals with investment in human resources and proposes a balance sheet approach to indicative planning. This exercise would be related to demographic projections in several variants. Other factors to be analysed dynamically would be education and health status, public finance and, ultimately, distribution of income and wealth since it is noted that the process of monetisation is having an impact which may have important welfare implications.

Notes: In this paper the author adds some further empirical tests of his theory of income distribution. This theory (cf. this Review, Series 16, Number 3, September 1970, p. 221 ff) sees income distribution as the distribution of prices of production factors, especially labour, of different quality and prices as the effect of demand and supply factors. The quality of labour is represented only by the number of years of schooling. Its supply is described by the actual numbers of people having each of the possible years of schooling; this frequency distribution can be characterized by its average and by some measure of its dispersion or by one of its deciles (in particular the highest) expressed in terms of its median. The demand for the various qualities of labour can be supposed to be reflected by (i) total demand for commodities, but (ii) more accurately by the percentage of third-level educated people used in and weighted by the size of the four main sectors of production: agriculture, manufacturing, trade and transport, and other services. Extensive material collected and reworked by Professors B. R. Chiswick for the U.S.A. and Canada and T. P. Schultz and L. S. Burns with H. E. Frech III for the Netherlands is used in cross-section tests to explain variations in income distribution in the states of the U.S.A. and the provinces of Canada and the Netherlands. The results can be found in the tables. While further increase and smaller dispersion in years of schooling, according to some of the findings presented, would only moderately reduce the degree of inequality in the U.S.A. and Canada, more result seems to be possible according to other findings, including those for the Netherlands. In the latter category the second demand index mentioned above has been used. This paper is one of several devoted in various ways to the testing of the same theory.

Notes: Statistics for developing countries often are misunderstood and misinterpreted because the published data do not distinguish between the economically modern and the traditional sectors. The purpose of economic development is to move a nation from the traditional, or largely non-monetary, subsistence agriculture type of life, to the modern or money oriented and technologically developed type. Statistics of national accounts, the economically active (the working force), and other topics often fail to be useful for economic development purposes because they are presented for the totality of the country and do not show the modern-traditional sectors separately.In addition, data are often misinterpreted and used incorrectly because the development economists do not understand the nature of the data—how they were collected and what they really signify. This point is illustrated with the economically active statistics. Finally, a plea is made for more statistics and information about families.

Notes: This paper deals with some results of an extended investigation which was carried out by the German Institute of Economic Research, Berlin, and the Ifo-Institute, Munich, and financed by the Stiftung Volkswagenwerk. For 29 sectors of manufacturing Cobb-Douglas production functions have been calculated, based on quarterly figures 1958–1968 of value added, input of hours worked, input of utilized capital stock (net of scrappage), and of potential value added, potential labor input and total capital stock. The income distribution is used as production elasticities. For each of the 29 sectors 12 time series of quarterly indices of total factor input and technical change have been computed, using utilized data (variation 1-6) and capacity data (variation 7-12). Two different time series of α are used, taking quarterly interpolated data (variation 1, 3, 5, 7, 9, 11) and the geometric mean 1958–1968 (variation 2, 4, 6, 8, 10, 12). Moreover three different parameters of homogeneity are introduced, taking r= 1 (variation 1, 2, 7, 8), r= 1.1 (variation 3, 4, 9, 10) and r= 1.25 (variation 5, 6, 11, 12). Seven of the 29 sectors show a very high sensitivity of the rate of technical change due to the assumed r, six sectors a rather high sensitivity. Ten of the 29 sectors show a rather small sensitivity of technical change due to the assumed r, six sectors a very small or even negative sensitivity, i.e. an increasing r creates an increasing technical change. These results can be explained by taking account of the fact that total factor input in many branches increased very slowly or even decreased (labor input alone decreased in nearly all branches). A hierarchy of technical change has been calculated; this hierarchy is difficult to explain, because fast growing industries as well as industries with a small or a negative growth rate of output rank in both the leading and the last group of technical change. Very high rates of output result in high rates of technical change (chemicals, mineral oil refining, plastics manufactures), but some industries with a rather small growth of output (shipbuilding, fine ceramics, steel drawing, and cold rolling mills) show a high rate of technical change too.

Notes: An underlying theme in this paper is that the differences in approach in this area arise partly from the complexity of the phenomena in the real world being studied, the implications of this interrelated complexity for unbiassed and efficient estimates of the structural relations, and the problems of getting an adequate number of observations of the required form.Two distinct approaches have been used in the study of marginal and total factor productivity. One approach is to use the factor shares in national income as weights to combine the individual factor inputs to make an index of total factor input, and to use a factor's relative share to measure its marginal contribution. The second approach is to estimate the production relation from the data being used, and derive the marginal contribution of the productive factors to output from the estimated relation. The longest parts of the paper review the procedures followed to cope with the main problems in the real world, and the strengths and limitations in the two approaches. The discussion emphasizes the issues for the economy as a whole, and touches only briefly on the issues in disaggregation.Three major themes are emphasized in the conclusions to the paper. One is that many of the problems, the differences in view, and the controversies grow out of the range of interrelated issues in practical applications. A second major theme is that most of the attempts to solve particular issues by those using the factor shares approach are rather similar to those followed by researchers estimating the production relations directly. A third theme is to encourage more studies that will look at the interconnections between production relations and income distribution, from the points of view of both economic theory (and its predictions about the relevance to concrete applications) and statistical estimation.

Notes: This paper summarizes the results of several studies on total factor productivity of twenty-five countries over the period 1950–1965. Some methodological issues which underlie the derivation and calculation of the familiar partial and total factor productivity indices are discussed. Though evidence on labor productivity for a large number of countries is presented and discussed, the main thrust of the discussion is in terms of the determinants of total factor productivity. The quantitative and qualitative contributions of labor and capital to growth of income are assessed with special attention to the contrasting patterns of these contributions among developed and developing economies. The problems of acceleration and retardation of the growth rate of some economies are considered and possible explanations are offered. Variations in the magnitude and sectoral distribution of the growth rates in several countries over this period are examined. Finally, areas for further research in comparative economic growth are suggested.

Notes: This paper discusses the estimation of the CES Production Function with Hicks-neutral technical change, and gives the results of an empirical study based on time series data (quarterly values) for sixteen industrial sectors in the Federal Republic of Germany (including West-Berlin), 1958–1968. The validity of the basic assumptions of the production model used in this investigation—neutrality of technical change and perfect competition—is tested by estimation of alternative specifications of the equations of this model. For this purpose two different methods of estimation were used.

Notes: Developing countries which typically have import surpluses and inflationary pressures because of insufficient savings are prone to use indirect taxes on imports (Tm) and subsidization of exports (Sx) in order to prevent deterioration of the balance of trade. If these substitutes for devaluation are included in the net indirect tax component of product at current market prices (Ym) the import surplus is likely to be understated, and Ym upward biased. This distortion will be avoided if imports and exports are measured at effective exchange rates (ER), that is, at official rates (OR) plus Tm and Sx respectively, and if (Tm - Sx) is deducted from the net indirect tax component of Ym. Only in this manner become imports and exports consistent with the other uses and resources at market prices and can be articulated with them. At base-year prices the volume index of product at OR diverges from that of ER to the degree that the composition of imports and exports in regard to tax and subsidy rates computed ad valorem significantly changes.Such a case is similar to that of the price indexes of imports and exports moving in diverging proportions: the trade balance at base-year prices will differ from that at current prices. The resulting discrepancies in national accounts have led to proposals of deflating, for example, exports by the price index of imports. Suchlike approaches are incompatible with the principle of national accounting that prices are supposed already to measure substitution values. Deflating exports by import prices means reintroducing substitution values, as does, for example, deflation of incomes by a consumer price index. Correspondingly, since the trade balance at ER conceptually expresses the value of imports at domestic market prices as compared to the corresponding domestic market value of exports, and if at ER the trade balance diverges from that at OR, the former balance has an important meaning (as has the trade balance at base-year prices as compared to that at current prices) and the resulting discrepancy between the two measures should not be removed merely for the sake of accounting smoothness.In contrast to the market price approach, the measurement of product at base-year factor cost is indifferent to the measurement of the trade balance at ER and at OR.It is, therefore, proposed in countries in which part of import taxation and export subsidization substitutes for devaluation, to record imports and exports in the national accounts at effective exchange rates, and to correct the net indirect tax component of product correspondingly. Imports and exports at official exchange rates should be shown within the balance of payments, and the latter separately as a memorandum item.

Notes: Changes in many output determinants contribute to growth. An analysis of the sources of growth is an allocation of changes in output among these determinants. Total factor input and output per unit of input condense all determinants into two groupings. Misinterpretation of results is common because authors presenting either detailed or summary results often provide no complete or precise description of their classification of determinants, and readers ignore even the information provided. The classification suggested in this paper is detailed enough to bring out points at which description is required but often overlooked. Some effects of alternative estimating procedures on classification are described.The relative usefulness and practicality of possible alternative classifications also need consideration and discussion. This paper is concerned with general purpose classifications, appropriate for analysis of actual series measuring a country's total output, that are suitable for present use but will also accommodate useful detail that may later become feasible. A desirable classification will so specify determinants that (1) they both unite cause with effect and correspond to the economist's method of analysis so that his set of tools can be brought to bear; (2) they do not contribute to growth if they do not change; and (3) they conform as well as possible to practical possibility of estimation. Among several points considered fundamental are that the complete contributions of advances in knowledge and of resource reallocation each appear as an entity. They should not be dispersed among inputs or other determinants. It is less clear whether economies of scale should be a separate determinant or their contribution be dispersed.

Notes: Conventional measures of national product make no pretence of including everything that affects welfare. As increasing attention is being paid to environmental pollution, the problem of incorporating certain non-economic variables into the analysis of well-being becomes more relevant. The object of this note is to show how a difference in “needs” for, and hence expenditures on, anti-pollutants, which will show up in conventional national accounts comparisons as differences in “tastes”, should be converted into differences in real income.

Notes: The CMEA standard of statistical information provides a system of national wealth indicators. The paper deals with certain time series published in these countries and in the CMEA Statistical Yearbook as the components of that system. Special attention is paid to the USSR interbranch balance of 30 types of fixed assets cross-classified by 105 branches of economy. This balance is analogous to the input-output table technique in the western literature. On the basis of this balance the Soviet statisticians furnish coefficients of direct and total requirements in fixed assets for each branch. Such coefficients are usually called capital ratios or capital coefficients. In the USSR they are calculated together with the coefficients of direct and total requirements of labour for the same industries, and they supplement input-output tables. The scheme of the fixed assets balance and the matrix for the calculation of these coefficients are described in the paper together with some numerical illustrations of actual coefficients reached in the calculations.

Notes: The purpose of this paper is to investigate the sources of economic growth in Japan and to compare the results with those in the U.S. and Europe as studied by E. F. Denison. The method used by Denison is followed as far as possible. The character of this paper is of fact finding, and the interpretation of results or the originality of methodology is not dealt with here. The results may be summarized as follows.(1) Japan's growth rate is two times that of Europe and three times that of the United States.(2) The contributions of labor, capital, and the residual to economic growth are all higher for Japan than for the U.S. or Europe.(3) Factors which account for the higher contribution of labor to economic growth are (a) the higher rate of increase in employment, (b) less shortening of working hours, and (c) improved age and sex composition.(4) Factors which account for the higher contribution of capital to economic growth are a higher rate of increase in capital input and the high elasticity of production with respect to capital.(5) Other notable points include: (a) the contribution of education is lower for Japan; (b) the capital-labor ratio in Japan increased remarkably; (c) capital's share of national income is higher; and (d) 60% of Japan's economic growth is accounted for by the residual.

Notes: This paper analyses productivity growth in the Hungarian economy over the two decades between 1950 and 1970 with the aim of establishing what help can be provided in such analyses by the use of total factor productivity index numbers. After the introductory sections the paper deals first with the rates and factors of Hungarian productivity growth, and then with some methodological lessons of the investigation.

Notes: The paper discusses the relevance of input/output tables as a tool for economic analysis and planning in developing countries. It contends that this is so only to the extent that the input out-put tables enable consistency of production accounts to be verified while providing a suitable basis for macro projections at the same time. As a by-product, such input out put tables, the paper adds, also provide a convenient framework for estimating the needs for extensions and improvements in basic statistics.All these requirements, it is stated, can be fulfilled by a relatively aggregated format of an input/output table—which some of the developing countries are in a position to compile. However, the paper states, it is feared that the case for input/output analysis is not based on these requirements. The main force of arguments is in fact based on the uses of input/output tables for more detailed sectoral analysis and projections. The current state of basic statistics on some key sectors, it is stated, is not sufficiently sound to yield an end-product which is reliable. In the case of sectors where this is so the input/output analysis is not relevant either because of concentration of production in a relatively few establishments or because of limited amount of inter-sectoral interaction. It is further felt that if such arguments were to be accepted by developing countries the result would be a distorted disposition of statistical resources. Immediate needs of the developing countries require concentration of effort in development of more reliable and relevant series on basic statistics.

Notes: At present two systems of measurement of national product are in practice, one as defined in the UN System of National Accounts (SNA) and the other termed the Material Product System (MPS) or National Balances for the Economy. In the present paper, an expanded system of accounts integrating the national balances within the framework of a simplified SNA has been suggested. The accounts suggested are mainly the two sets of (i) Supply, Disposition and Domestic Production of goods and services and Consumption Expenditure of Budget and Mixed Organisations and the Population, and (ii) Income and Outlay and Capital Formation Accounts.The system is convenient not only for arriving at estimates by either of the two approaches, but is readily manageable. This set of accounts can, without any effort, be put in the form of a matrix leading to its ultimate integration with either the UN System of National Accounts or a modified system of national balances.The system gives not only the integrated system of SNA and national balances, but also a coded list of transactors and transactions within the economy. This coded list can be used as the first set of information for the creation of the economic data bank for the Integrated Statistical Information System.

Notes: An announced in the December 1971 issue of this Review, the Thirteenth General Conference of the International Association for Research in Income and Wealth will be held in Hungary in August of 1973. Persons interested in submitting papers to be considered for presentation in any of the sessions are reminded that they should communicate with the session organizer as soon as possible. A list of topics and session organizers will be found in the December 1971 issue of the Review.

Notes: The author describes the results of his current research designed to measure total investment, tangible and intangible, and the derived capital stocks for the U.S., 1929–1966. With respect to total investment, the estimates show a marked increase in its ratio to GNP. All of the increase occurs in the intangible component comprising R & D, education and training, health, and mobility. The increase was concentrated in the government sector, although households increased the proportion of disposable personal income devoted to total investment.Consistent with the relative investment trends, the stock of intangible capital grew considerably faster than the tangible stock. The growth of total capital stocks was somewhat less than that of GNP, however, in both current and constant prices. Thus, the rate of return on total capital rose somewhat over the period. Average rates of return on human and nonhuman capital were closely similar.In real terms, the growth of total capital stocks accounted for two-thirds of the growth in real GNP, 1929–1966. One-third of the growth is attributed to residual forces, chiefly economies of scale, changes in inherent quality of human and natural resources, changes in values and motivations, and changes in rates of utilization of capacity.The growth of the ratio of real intangible stocks to real tangible stocks accounted for less than half of the increase in total factor productivity 1929–1966. This is significantly less than the contribution of intangibles as estimated by Denison, and the author adduces several reasons why his estimates may understate the contribution. Nevertheless, it seems that the net effect of the residual forces enumerated above must also have made a substantial contribution to the growth of tangible factor productivity and real GNP over the 37-year period.

Notes: The interpretation of Turam data is treated by means of a development of the conventional approach to this type of data. The development consists of a curve matching technique based upon a line current approximation to the true induced current pattern.The technique requires computation facilities which are readily available in modern programmable calculators.Practical examples of the use of the method illustrate that it can reveal information concerning the geometry of a conducting body which would not be gained by the conventional approach.

Notes: “Remote sensing” techniques have been used for many years as an exploration tool; broadly speaking, any method using sensors not directly connected to the earth's surface falls into this group.It is preferable, however, to use the term solely with reference to a number of new sensors which have recently become available to earth scientists for the detection of various radiations of the electromagnetic spectrum in the wave length range from 0.1 micron (UV) to some centimeters including the visible and infrared regions.Radiations artificially induced in the earth (active sensing) or spontaneous radiations (passive sensing) can be detected. Some of the bands investigated seem promising for application to geological surveys, especially using sensors on aircraft and satellites, which allow synoptic and large scale investigations.A brief account is given of the results already achieved and of future developments such as the ERTS and manned satellite (post Apollo) “earth observation” programmes.The potential role of Europe in the field is discussed.Details are given of some applications of thermal I.R. imagery to geological and vulcanological problems, with special emphasis on the research carried out in Italy.

Notes: In mathematical statistical filtering the deconvolution problem can be solved by two different methods:〈list xml:id="l1" style="custom"〉1by inverse filtering2by calculating the prediction error.Both methods are well known in the theory of Wiener filters.If, however, the generating process of the signal is known and can be described by a set of linear first order differential equations, then the Kalman filter can also be used to solve the deconvolution problem. In the case of the inverse filtering method this was shown by Bayless and Brigham (1970). But, while their method can only be used if the original signal is a colored random process, this paper shows that in the case of a white process the prediction error filtering method is a more appropriate approach. The method is extremely efficient and simple. This can be demonstrated by an example which maybe of special interest for seismic exploration.

Notes: The use of the electrical image method in calculating the potential of a source in the presence of a buried conductive sphere proves to be difficult because of the great number of terms making up the potential formula. The disadvantages contained by this method are avoided here by resorting to the theory of graphs. In view of this aim the “propagation” of the electrical images due to the sphere has been represented by an infinite graph to which an infinite matrix has been attached.Taking this as a basis several FORTRAN IV programs for the computation of resistivity pseudo-sections for various electrode configurations have been coded, and a great deal of such pseudo-sections have already been calculated with an IBM-360 computer. Using these results, recommendations regarding both the methodology of the geoelectrical prospecting of spherical shaped conductors and the most suitable way of building resistivity pseudo-sections are developed.

Notes: An account is given of the use of the square array technique in investigating the surface effects of rotational anisotropy when the axes of anisotropy are inclined to the surface. It is shown that, as with other arrays, two anisotropy parameters 〈inlineGraphic alt="inline image" href="urn:x-wiley:00168025:GPR249:GPR_249_mu1" location="equation/GPR_249_mu1.gif"/〉 and n can be derived by varying the array orientation.On the basis of these considerations, the effects of such anisotropy on the values of the mean apparent resistivity and azimuthal inhomogeneity ratio normally obtained in square array measurements is reviewed.Particular attention is paid to the variation of resistivity with orientation and it is noted that, in areas of moderate anisotropy, this variation is lower for the square than for the Schlumberger array.In addition to this advantage, the azimuthal inhomogeneity ratio obtained from square array measurements may be used to indicate the severity of anisotropy in an area and two field examples of this use are given.Where anisotropy is severe, gross variations of apparent resistivity with orientation are obtained with either square or collinear arrays. In these circumstances, the use of crossed measurements is considered and the particular stability of the crossed square array demonstrated.

Notes: Electrical resistivity sounding was attempted with success in 1960 on the surface of the Nile water in Khor Kundi El-Bahari, the starting place for the construction of the offset channel of the High Dam. The method was applied to determine the depth to the upper surface of the granite below the alluvium and Nile water. The success of the method conducted at two stations in the Khor is attributed to the favourable geological conditions of the section which consists of nearly homogeneous layers besides the good earthing conditions of electrodes dipped in water. The high resistivity contrast between water and granite facilitates interpretation of sounding curves. Factors interfering with the results of interpretation are mentioned.

Notes: This paper presents a dot chart for calculating gravity effects from two-dimensional bodies with the addition of a supplementary set of curves which can be used to determine the “end corrections” to modify the calculated effects when the length of the body is not relatively long with respect to the horizontal dimensions of the cross-section. The use of the chart is demonstrated by different examples. The results of theoretical cases amenable to mathematical treatment and computer results both compare favorably to those computed using the present chart.A fundamental incentive of constructing this chart, in a final form ready to use, is to make it available to gravity interpreters for utilization. Future effort in chart construction is thereby avoided.

Notes: By applying dynamic corrections a seismic trace recorded at a distance x from the energy source should be varied in such a way as to obtain a trace which would be recorded at zero-distance, i.e. at the source itself. Only such a zero-offset-trace contains the correct sequence of reflection coefficients (reflectivity function), whilst all other traces contain a distorted reflectivity function. In the simplest case, the reflectivity function is compressed over a shorter time whereas in more complicated cases a partial inversion of the reflectivity function results. This happens when some of the reflection hyperbolae intersect one another.The reconstruction of the true zero-offset reflectivity function by the application of dynamic corrections can only be an approximative process. In the first case mentioned we must expect a decrease in accuracy of the corrected trace in comparison with a zero-offset-trace. In the second case, where intersections of the hyperbolae occur, accurate reconstruction is clearly impossible.The problems are discussed with the help of theoretical and practical examples.

Notes: Fourier transform techniques have been used to calculate the theoretical filter (amplitude) response function of Nth order vertical derivative continuation operation. The amplitude response functions of the vertical gradient and its continuation follow from the same. These response functions are subsequently used to calculate the weighting coefficients suitable for two dimensional equispaced data. A shortening operator has been incorporated to limit the extent of the operator. For comparative study, some of the developed coefficient sets and the one presented in this paper are analysed in the frequency domain and their merits and demerits are discussed.

Notes: In this paper it is shown how one may obtain a generalized Ohm's law which relates the induced polarization electric field to the steady-state current density through the introduction of a fictitious resistivity defined as the product of the chargeability and the resistivity of a given medium.The potential generated by the induced polarization is calculated at any point in a layered earth by the same procedure as used for calculating the potential due to a point source of direct current.On the basis of the definition of the apparent chargeability ma, the expressions of ma for different stratigraphie situations are obtained, provided the IP measurements are carried out on surface with an appropriate AMNB array. These expressions may be used to plot master curves for IP vertical soundings.Finally some field experiments over sedimentary formations and the quantitative interpretation procedure are reported.

Notes: In the linear filter method of interpreting resistivity sounding data, as developed by Ghosh (1971), it appears that the filter function in the x-domain approaches an oscillating function for both large positive and large negative abscissa values. In the present note the reason for this oscillating behaviour is derived, and a possible practical application is indicated.

Notes: Amplitude spectra of input FM signals used in the vibratory source method of seismic exploration often show undesirable oscillations near the initial and terminal frequencies. These oscillations have an effect on the correlation background and distort the output signal. Considerable improvement in reducing the amplitude of these oscillations is obtained using a proper taper fuction. Attention is given to the relation between the tapering time and bandwidth of the spectrum.Analyses of the spectra of the received data from vibratory sources show considerable attenuation in comparison with the original field sweep. Since the matched filtering process will result in a series of waveforms which have the shape of the autocorrelation of the input signal, consideration is given to the autocorrelation function and its zero-lag coefficient of the FM signal in the presence of attenuation. A method has been developed which compensates for the attenuation and recovers the distortion of waveforms when the received data is correlated.The design of a waveform shaping filter for vibratory source data is given to reduce the influence of phase distortion on the received waveforms as well as to increase S/N ratio resolution. Parameters used for this filter are based on the properties of the FM signal and its autocorrelation function.Several examples from field data are presented to illustrate the methods. The results indicate that the use of the above techniques yields sections with good frequency resolution and improved S/N ratio.

Notes: Three groups of 8 Polled Dorset Iambs were weaned at 8 weeks of age and were fed dried grass, a 50–50 mixture of dried grass and protein-supplemented barley and protein-supplemented barley. All rations were completed. Digestibility trials were also conducted and the effect of level of feed intake on nutrient digestibility investigated.The dried grass resulted in rates of gain comparable to those produced by the pelleted barley ration. Feed conversion efficiency was lowest for the grass and highest for the barley ration. An interaction between the dried grass and barley was observed in nutrient digestibility. Increasing the level of feeding from approximately maintenance to appetite tended to result in slight depressions in the digestibility of energy and protein of all rations.The results suggest that dried grass can be used successfully for intensive feeding of early weaned lambs and little nutritional advantage appears to be gained from combining dried grass with barley.

Notes: For spaced plants of Lolium perenne cv. S24 at the Welsh Plant Breeding Station, Aberystwyth, and at the National Institute of Agricultural Botany, Cambridge, linear relationships were obtained between the recorded heading dates and (a) mean March earth temperatures at 30 cm depth and (b) mean March plus mean April earth temperatures at 30 cm depth. The residual standard deviations were ±2.97 days and ±2.65 days, respectively, A mean March earth temperature of 8°C predicted heading on 5 May, 6° C predicted heading on 12 May, and 4°C predicted heading on 20 May. For sites with an average April temperature significantly below 8.7°C a correction of +2 days per degree mean temperature difference in April had to be applied to these dates. These equations could be used to predict dates for 50% ear emergence in swards with a 50% confidence limit of ±22 days for sites in Central and Southern England and Wales. In certain years, cold, wet weather in May appeared to delay heading considerably at two Scottish sites.

Notes: Book reviewed in this article:BEST, K. F.; LOOMAN, J.; CAMPBELL, J. B. Prairie grasses identified and described by vegetative charactersSHLYK, A. A. Chlorophyll metabolism in green plantsDEVLIN, R. M.; BARKER, A. V. PhotosynthesisEVANS, L. T. (Editor). The induction of floweringMACHLIS, L.; BRIGGS, W. R.; PARK, R. B. (Editors). Annual review of plant physiology.

Notes: A grazing experiment using four stocking rates of sheep, equivalent to 34, 45, 57 and 68 sheep/ha on an assumed 200-day grazing season, was conducted using a portable grazing corral technique. Plots were subjected to fotir grazing periods between mid May and early September. The effect of stocking rate on herbage yield and quality and the influence of these factors and feed intake on liveweights of the sheep were recorded.The mean daily herbage organic matter available over the trial was 9.6, 5.8, 3.3 and 23% of the total liveweight of the sheep at each of the four stocking rates. The highest grazing pressure led to the production of high-quality herbage, but also led to reduced productivity, low feed intake and liveweight losses. The most lenient grazing pressure failed to provide adequate herbage utilization. Even at the most intensive stocking pressure, only 66% of the herbage available to ground level was utilized in grazings after July.Intake results suggested that sheep of 45 kg liveweight required 1000–1200 g digestible organic matter per day to maintain body weight. Despite the higher in vitro digestibility of herbage on offer at the higher stocking rates, intake was limited through lack of herbage; a high degree of correlation existed between herbage availability and herbage intake over the four stocking rates and at all grazings.It is concluded that the portable corral technique is well suited for grazing studies and the assessment of sward response to varying stocking rates and is particularly useful where facilities for more extensive studies are limited.

Notes: Groups of 8 steers weighing 300–400 kg (660–880 Ib) were rotationally grazed on a ryegrass-dominant pasture for 115 days. The systems compared were zero grazing (Z), field grazing conducted at the same stocking rate (FC), and field grazing conducted at a stocking rate varied with the intention of giving the same liveweight gain per uiimal as zero grazing (FV). Mean daily liveweight gains were: Z, 0.98; FC, 0.78; FV, 0.90 kg/animal (2.2, 1.7 and 20 Ib/animal), and liveweight gains/unit area were in the ratio 100:78:85. Organic-matter intake, measured on four occasions, was, on average, Z, 6.54; FC, 6.18; FV, 687 kg/head daily (14.4, 13.6 and 15.1Ib).From these results it appears that a comparison of zero grazing and field grazing made at the same stocking rate is likely to underestimate the potential of field grazing for beef production from grass.

Notes: An experiment was conducted in two successire years to measure the effect of two levels of fertilizer N, 50 and 300 kg/ha (45 and 270 Ib/ac) on the productivity of pastures grazed by young beef cattle. Two stocking rates were imposed at the lower N level and 4 at the higher level. The responses per kg fertilizer N were approximately 1 kg liveweight gain, 20–24 Meal ME and 8–9 kg DM. Maximal yields of about 1000 kg gain/ha (890 Ib/ac) and 19,000 Meal ME/ha (7700 Mcal ME/acre) were recorded.Animal performance was similar on the low and the high N pastures. There was evidence that the chemical quality of pasture was lower on the low N pasture in the first year, but there was no difference in the second year.The numbers of dung pats per ha and the refusal of herbage due to fouling were reduced by Increasing the stocking rate.

Notes: Ways of using nitrogen fertilizer and long growth periods to produce grass for summer milk production are described. To exploit the extra production obtained from long growth periods it is suggested that the grazing system should be flexible, integrating cutting with grazing.

Notes: Five substrates (high-quality brome grass, low-quality brome grass, lucerne pellets, lucerne cubes, and barley straw) were analyzed for DM disappearance in a two-stage in vitro system in nine consecutive runs. Samples for each run were inoculated in duplicate with four independent collections of rumen fluid from the same mature, non-lactating Holstein cow. Data repeatability was excellent for the two lucerne substrates, good for high-quality brome grass, and poor for low-quality brome grass and barley straw.

Notes: Winter (vernalized) and summer (non-vernalized) timothy tillers were grown to anthesis in day/night temperature regimes of 32/26°, 27/21°, 21/15°, and 15/10°C. Herbage and total plant yields, total leaf-blade number and area, and total plant growth-rate were highest, or very nearly so, in the 21/15°C regime for both the winter and summer plants. However, summer plants reached anthesis 13 to 14 days later than winter plants in each temperature regime. Even though virtually all primary shoots produced an infiorescence, summer plants had significantiy more leaves and leaf-blade area, produced significantiy higher yields of leaf blade, stem plus sheath, stubble, and root tissues and had a significantly higher total plant growth rate than winter plants in each temperature regime.

Notes: Fifteen out of 36 possible combinations of 3 cutting dates for hay, 3 rates of N application and 4 intervals between N application and cutting date were compared to study the effects of pre-harvest application of N on the N, P, K, Mg and Ca contents of the aftermath and the effectiveness of utilization of these elements.According to the method of calculation given by ARC (1), the control haycrop harvested on 16 June was deficient in N, Ca, P and Mg, and the aftermath which was given no further N after harvest was of low bulk, but adequate in mineral content. Earlier harvesting improved the quality of the hay, and increased the bulk and reduced the mineral content of the aftermaths. Applying 125.6 kg N/ha after harvest resulted in a satisfactory increase in bulk, plus an improved mineral content in the aftermath. Applying N before harvest resulted in increased uptake of N, K, Ca, P and Mg in the hay and in the increased percentage of N, K, and Ca in the DM of the hay. Very early application of pre-harvest N increased the percentage of Mg.The general effect of pre-harvest N on the aftermath was to reduce yield and uptake of N, K, Ca, P and Mg. Doubling the pre-harvest N raised the mineral uptake. Very early pre-harvest application resulted in low mineral uptake in the aftermath. The percentage of N, K and P in the aftermath was reduced by pre-harvest N applied at both levels and on both dates.Deferring the application of fertilizer N until 4 days after harvesting the hay crop produced the highest mineral contents in the aftermath, without reducing its bulk.Mineral uptake in the regrowths was linearly related to N uptake at 1.43 kg K, 0.34 kg Ca, 0.157 kg P, 0.006 kg Mg/kg N uptake.

Notes: This paper describes experiments carried out with different depths of topsoil and methods of cultivation on an ash lagoon at Besthorpe, near Newark. Good yields of grass were obtained even on bare ash with suitable rates of fertilizer application. In the conditions existing at Besthorpe, the optimum depth of soil appeared to be three in. (7.62 cm), but the depth of cultivation (three in. (7.62 cm) or twelve in. (30.48 cm), die latter resulting in mixtures of soil and ash, had no significant effect.B uptake by the growing plants was markedly lower in the third year of the experiment but, apart from its possible effect on yield, it produced no ill effects.

Notes: The acid-detergent fibre (ADF) contents of 50 grass samples of known in vivo and in vitro digestibility were determined by hydrolysing with acid for 1, 2, 3,4, 5, and 6 h. The 50 samples used consisted of 6 Lolium perenne, 9 Cenchrus ciliaris, 15 Chloris gayana, 10 Digitaria spp., and 10 Setaria spp. Regression and residual standard deviations (RSD) were calculated for each hydrolysis time for each grass and for all 50 samples.Increasing the hydrolysis time decreased the RSD for Lolium perenne and Setaria, had no effect on Chloris gayana and Digitaria and increased the RSD for Cenchrus ciliaris regressions. For regressions based on all 50 samples die RSD varied between ±4.8 and 5.0 digestibility units with only minor differences between hydrolysis times. Correcting the ADF for contaminating ash generally increased the RSD.Changing the acid strength from the 10 N recommended by van Soest (8) did not lead to any major improvement in the RSD for regressions based on Cenchrus ciliaris, but with Setaria the RSD was reduced from ±2.8 to 1.7 digestibility units when 2N acid was used and hydrolysis was extended to 2 h.It was concluded that unless the optimum conditions for determining ADF for each grass are known then the in vitro technique provides digestibility estimates with a lower error.

Notes: A coring technique (6), that may be used for estimating the mean amount of herbage on closely grazed pastures, has been adapted to include visual scoring. Two methods are described, both of which use sets of pasture cores from the sward as reference standards. The observers score the herbage on view at random sites against the standards. In the first method the scores are converted to herbage yields directly by reference to the yields of the standards. In the second method a double sampling regression technique is used and the set of standards is used as a visual guide only.

Notes: Soil samples were taken at 0–1 in. (0–2.54 cm) and 1–3 in. (2.54–7.62 cm) depths on five occasions over a period of 55 days from under (3 in. (7.62 cm) radius from centre) and around (9 in. (22.86 cm), 12 in. (30.48cm) and 18 in. (45.72 cm) radius from centre) dung patches deposited on pasture. The samples were analysed for available N, K and P. There was a significant increase in the level of all three elements in the 0–1 in. samples beneath the dung patch. The increase persisted throughout the experiment. K exhibited the greatest increase, but was not detected beyond the edge of the dung patch. The increase in soil N was smaller but was detected up to 6 in. (15.24 cm) from the edge of the dung patch. P also increased, but was more variable than either N or K. Soil N, P and K did not increase in the 1–3 in. samples.The weight and fibre content of the dung patch was also measured throughout the experiment. After high initial losses (25%) the dung patch decayed only slowly.The loss of ammonia from dung patches was followed over 13 days in a separate experiment During the relatively hot weather over this period approximately 5 % of the N iu the dung was lost as ammonia, mainly in the first five days. During the experimental period of 13 days 60% of the original weight of the dung patch was lost through evaporation.The results are discussed in relation to the growth of herbage surrounding a dung patch reported in the previous paper (12).

Notes: The problem of a plane wave incident on a non-isotropic dipping layer lying over an isotropic conducting substratum has been studied and some numerical results are presented to show the effects of〈list xml:id="l1" style="custom"〉1) degree of anisotropy m,2) conductivity contrast between the substratum to the upper layer b,3) angle of inclination of the axis of anisotropy α,on the variation of amplitude and phase difference of the wave impedance with the normalized skin-depth (d/δ1).

Notes: Consideration of the spectral representation of gravity and magnetic fields shows the field to be the result of the convolution of factors depending on the parameters of the field. Wiener filters, calculated using model transformations, provide an optimum method for altering these factors and hence effecting field transformations.

Notes: A discussion is given of the requirements, the advantages and the methods to be considered in attempting the quantitative interpretation of gravity or magnetic fields from computed maps of the vertically derived field.The transform which is used here is the first vertical derivative (or vertical gradient) with or without downward continuation, but the computed maps are in fact obtained by a controllable Fourier method in which two kinds of operations can be simultaneously performed in complete independance: on one hand the separation of any part of the data by frequency cut-off, and on the other hand the transformation by vertical derivation or continuation of the part which is retained.Taking as raw data either actual surveys or artificially constructed maps, it is first shown how separated and transformed maps of this type can be efficiently obtained under quite flexible conditions, using a special computer program. It is further seen that for correctly controlled filterings the accuracy of the computed maps actually permits to take them as the basis for quantitative interpretation.To effect this, any one of the conventional methods which make use of equivalent model computations may in the first place be adapted to the interpretation of gradients, with the benefits, however, of an enhanced lateral separation of the anomalies and of a large attenuation of the regional effects.Particularly, the delineation of horizontal contours for even fairly complex models can often be made directly in a sufficiently safe way on the anomalies as they show on the vertical gradient maps. This greatly accelerates the process of determining equivalent model bodies.More special methods of interpretation can also be designed by taking into account first the fact that the vertical derivation of the field amounts to an operation of separation on the field's sources themselves, and in addition the availability of the frequency form of the information as a result of using a Fourier method of transform computation.Trial utilisations of various such interpretation processes of either the conventional or the less conventional type, are presented especially in connection with an interpretation study on transformed maps of parts of an offshore aeromagnetic survey (English Channel).

Notes: Generation of electrical power through the use of natural steam obtained from the Earth has the potential to be a significant source of pollution-free power. Successful future exploitation of geothermal power depends upon the development of cost-effective exploration techniques. A field experiment in the Imperial Valley of California indicates that there is a close empirical relationship between hot water deposits at depth and an anomalously high seismic background level at the surface. If this relationship proves to be a general one, it will serve as the basis of a simple and inexpensive method of geothermal exploration.

Notes: In massive rocks ground waters mainly flow in fracture zones whose permeability greatly changes depending on their filling. When studying ground-water flow in fissures, the results of observations of the electric fields of filtrational origin—which, in this case, considerably differ from those in porous media—can be used. Therefore the authors have made experiments on fissured media models. The measurements have been made in a special filtration tube with the fissured media simulated by a system of quartz glass plates. The spacings between plates were regarded as fissure widths. The observations have been made in fully open “fissures” and in those partially filled with sand or sandy-clay material.These experiments have resulted in establishing a dependence between the values of streaming potentials and pressure drops. The SP values have particularly been found to decrease with the opening of “fissures”. The most intensive electro-filtrational fields were observed at 40 per cent filling with medium grained sand. Additions of argillaceous material to the sand filler brought about sharp reductions in the intensity of electro-filtrational potentials.

Notes: During the last few years the airpulser, or air gun, has become very common as an energy source for marine seismic surveys. This paper describes the physical processes which take place during the operation of the pulser and develops theoretical results concerning the energy and frequency of the radiated signal and the amplitude decay of the secondary bubble pulses. The theory takes into account the presence of the airpulser itself which is assumed to be a rigid sphere within the bubble of released air. The theoretical results are combined and compared with measurements made of the pressure within the airpulser, the acceleration of the body of the pulser, and the amplitude and frequency of the signal radiated into the surrounding water. A formula for calculating the bubble frequency is given and a diagram made of the energy partition between mechanical losses, radiated energy, etc. Finally, a comparison is made of the energy release from the airpulser with that from TNT.

Notes: An equivalent stratum model is used to provide an explanation for the power spectrum characteristics of potential fields.The power spectrum of observed magnetic fields is found to consist of effects due to sources which can be represented by apparent monopoles and dipoles. Similarly, the power spectrum of observed gravity fields is found to consist of two groups of effects. A matched filter is proposed whereby the effects due to the two components in the potential field can be separated. As a consequence of the established theoretical expressions a scheme is suggested whereby the aliasing power of sampled data can be estimated. Also, the concepts of downward continuation, reduction to the pole, and reduction to pseudo-gravity of magnetic fields are re-examined in light of the theoretical expressions due to the equivalent stratum model.

Notes: The oscillatory character of the solution obtained by Qureshi and Mula's method for the direct determination of two-dimensional mass distributions from gravity anomalies is examined.

Notes: A number of resistivity profiles over dolerite and metadolerite dykes have been taken using Wenner and Schlumberger configurations around Dhanbad in order to find the potential of these for water accumulation. These dykes give rise to both resistivity highs and lows as compared to the background. The results are discussed in the light of known theories. Some suitable sites for water accumulation have been delineated.

Notes: Differential and difference soundings of resistivity for real, imaginary and complex values of the newly introduced parameters ν and μ are considered. The transverse and longitudinal differential soundings, known up to the present, correspond with the values ν= 1 and ν=— 1.The point of departure is the generalization of the concept of Dar Zarrouk parameters and the dimensional analogy between D.Z. resistivity and transverse and longitudinal differential resistivities. Properties of generalized D.Z. curves as well as the method of their construction are given. The examples of differential and difference curves are presented and the properties of these curves are discussed; particulary the effective spacings are determined. The problems of the realization of differential and difference soundings are considered; the bisymmetrical and asymmetrical arrays are proposed as a practical ones.

Notes: The seasonal pattern of DM prodaction of Lolium perenne, Cynosurus cristatus. Anthoxanthum odoratum. Festuca ovina and Agrostis stolonifera. cnt to 3 cm at 6-week intervals was studied on five sites, ranging from 49 to 303 m above sea level, in north-west Lancashire. Total annual production declined from a mean of 704 g/m2 on the lowest site, to 553 g/m2 on the highest, largely as a result of a severe depression in the spring peak of production, i.e. from 6.7 to 2.5 g/m2 per day. Later in the year, the daily rate of DM production was similar on all sites. Species varied in their response to increased altitude; Lolium was worst affected by this and Festuca least. The significance of these results, and possible reasons for the decline in spring production are discussed.

Notes: Tillering is examined in relation to the morphology and habit of growth of the perennial herbage grasses; particular reference is made to the effects of cutting and grazing. The importance of tillering in establishment and regeneration or perennation of a grass sward is considered; greater importance is attached to the role of tillers in the regrowth of swards cut for conservation at the reproductive stage of growth. Amounts of regrowth are related to both the number and size of vegetative tillers present at the base of reproductive tillers at the time of cutting. The probable inhibition of the replacement tiller buds by the developing inflorescence is suggested as a reason for the poor growth of grass swards in the favourable environment of midsummer.The physiological mechanisms which control tillering during reproductive development are examined. Spring and winter wheat (Triticum aestivum), Lolium temulentum and Phalaris tuberosa are used as physiological tools to demonstrate that tillering is restricted during reproductive development, and that stem extension may be more important than changes at the stem apex in controlling this restriction of tillering at the base of the inflorescence-bearing stem. It appears from results of the application of a range of growth regulators that substances derived from the meri-stematic centres, in either the elongating stem or the terminal meristem, indirectly control the metabolic activity of the lateral buds from which new tillers are derived. The degree of apical dominance is shown to depend on the light intensity in which the plants are grown. Finally, the physiological results are used to suggest reasons for the commonly found apparent inability of heavily fertilized perennial ryegrass (Lolium perenne) swards to regrow after cutting at the inflorescence-emergence stage of growth.

Notes: A study of the relationship between some farm and grassland management factors and milk production at the Hannah Dairy Research Institute in the period 1951–70 is reported. During this period various aspects of farm management were altered, and total annual milk production was increased from 28,400 to 63,900 gal. The major factors influencing total milk production, in order of declining importance, were: the overall rate of stocking, milk yield per cow, the numher of milking cows as a percentage of all animals, and the acreage of grass as a percentage of the total farm acreage. Stocking rate and milk yield per cow together explained 85% of the total variation in annual milk production. No significant relationship was found between total milk production and weight of concentrates fed/gal, the amount of fertilizer N applied/aC, rainfall and sunshine data. It is suggested that the lack of a direct relationship between milk prodnction and the amount of fertilizer N applied resulted from the contribution of N from clover and from grazing animals.

Notes: The loss of water from small bulk samples of five grass species was studied under constant conditions of humidity, temperature and lighting. A logarithmic curve was fitted to the data and the different species compared on the basis of a loss coefficient derived from the fitted curve. The species varied significantly in this aspect; those with high surface-area to dry-weight ratios generally lost water fastest The presence of stem material appeared to increase the rate of water loss considerably. High humidity during drying caused the grasses to lose water more slowly and to retain much more water at equilibrium with the surrounding air. Chemical treatments to speed water loss, using a solvent and a fungal toxin were tested. Both appear to have some promise. Selection for high water loss in grass breeding may also be possible.

Notes: Eighteen crossbred Aberdeen-Angus and six Shorthorn steers with an average liveweight of 382 kg were given silage (DM content 22.3%) ad lib., supplemented with 0, 1.2, 2.4 and 3.6 kg artificially dried grass, or 1.8 kg rolled barley, per day. A digestibility study carried out on the silage and dried grass showed that the concentration of the metabolizable energy was 52.7 and 45.6 kcal/100 kcal of food, respectively. Live-weight gain increased with each level of supplementation. Supplementation did not significantly affect the intake of silage DM, but differences in the intake of total DM were significant. The killing-out percentages of the steers were similar. The results suggest that dried grass pellets may be a usefid supplement for a silage diet. It was shown that 1.12 kg of dried grass was equivalent to 1.80 kg rolled barley as a supplement for silage.

Notes: Three groups of Hereford × Friesian steer calves, bom in early January 1969, were strip-grazed on eqoal areas of a sward of S321 perennial ryegrass from May to September inclusive, and received kibbled barley at the rate of nil, 3/4% or 1 1/2% of liveweight per day. Adjustments were made to the number of animals per group in order to maintain the same high grazing intensity (defined as 8 cm stubble height in grazed areas) on all treatments. The animals receiving supplementary barley gained weight at a rate 17–19% higher than the controls, but there was no significant difference in growth rate between the high and low levels of supplementation. The effficiency of conversion of barley was only 5–12 kg per animal liveweight gain/100 kg barley OM.The high level of supplementation resulted in an increase in stocking rate of 36 % over that of the control group, and an increase in liveweight gain per unit area of land grazed of 63%. The additional liveweight gain due to supplements, expressed per unit area of land grazed, was relatively constant at 21–24 kg liveweight gain/ 100 kg barley OM consumed.

Notes: Books review in this article:PERRING, F. [Ed.] The flora of a changing BritainWATER AND SOILS DIVISION, MINISTRY OF WORKS, NEW ZEALAND. Land use capability survey handbook. A New Zealand handbook for the classification of landNATIONAL ACADEMY OF SCIENCES, NATIONAL RESEARCH COUNCIL, COMMITTEE ON REMOTE SENSING FOR AGRICULTURAL PURPOSES. Remote sensing with special reference to agriculture and forestryHUGHES, D. E.; ROSE, A. H. [Eds] Microbes and biological productivity. Twenty-first symposium of the Society for General Microbiology held at University CoOege London April 1971

Notes: The effect of a conducting overburden on the electromagnetic response of sulphide ore-bodies has been studied with the help of quantitative electromagnetic model experiments. These experiments were conducted at a fixed, crystal controlled, frequency of 100 kHz using a number of transmitter-receiver configurations, though the results discussed here mostly pertain to a horizontal coplanar system. An analysis of the anomaly profiles—after accounting for the regional anomaly—indicates a general enhancement of the response. This is attributed (a) to the concentration of the current lines in the host-rock effected by the embedded target and (b) to the change in the phase and space orientation of the field vectors, brought about by the conducting overburden. The enhancement is most pronounced in the case of non-symmetrical bodies such as veins and ribbon-like structures represented by sheet models, but is also observed to a lesser degree for isometric structures. These results are expected to pave the way for a more accurate interpretation of the induction prospecting data.

Notes: Mit der vorliegenden Arbeit wird das Echo-Log als ein geophysikalisches Meßverfahren zur Bestimmung von Form und Volumensverteilung von Aussolungshohlräumen im Salzgebirge vorgestellt. Hierzu werden neue terminologische Begriffe wie Echo, Echostrahl, Echostrahler, Echozeit, Echogramm usw. erläutert. Weiter wird über die Meßausrüstung, Durchführung der Vermessung sowie die Ergebnisdarstellung berichtet.In einem letzten Abschnitt wird zwischen Echos, die auf einem direkten Weg von der Hohlraumfläche zurückgeworfen werden und anderen bei der Registrierung erfaßten Empfangssignalen unterschieden.In this paper the Echo-Log is presented as geophysical measuring method for determining form and volume spread of leached cavities in salt formations. Therefore, new terminological definitions like Echo, Echo Beam, Echo Transducer, Echo Time, Echogram etc. will be explained. Furthermore, also the measuring equipment, execution of a survey and the presentation of the results will be described.In the last paragraph the difference between Echo directly reflected from cavity walls and other in the cavities registered signals will be discussed.

Notes: The theory of potential field continuation is studied with a view of extending it to include continuation between non-linear surfaces. This theoretical extension is regarded as useful in reducing observed potential fields along one general surface to another general surface.It is demonstrated that the continuation operators considered in past geophysical literature are special cases of the generalized operators. In view of the tremendous growth in the art of high-speed computing it is possible to consider applications of the generalized operators. In worked examples upward continuation between a general surface and a datum is considered for the gravity field due to geometrically simple sources; this in order to test the accuracy of the digital applications. It is indicated that for observations on an undulating surface it is possible to account for considerable errors when, during interpretation, the observation locations are taken to be along a datum. For aids to profile interpretation in areas of considerable topographic relief some simple convolution operators for continuation between linear, non-parallel surfaces are proposed.

Notes: The ground follow-up of a magnetic and radiometric air survey had to cope with the usual dilemma to check a great number of anomalies within a short time. A limited aggregate of magnetic anomalies, expected to correspond to magnetite quartzites was statistically selected for ground identification by this method: the ratios length/width times amplitude were listed for all coherent contours and the calculation of the standard deviation per unit area resulted in different key-numbers for a new lithological “Salem Unit” and for the charnockitic or gneissic environment. The ground work thus directed and reduced by 85% yielded a substantial potential of iron ore. This was supported by by abundant determinations of the magnetic susceptibilities, confirming the sources of anomalies and revealing the amenabilities of iron ores for the magnetic separation process.The lines of truncation of anomalies were found to represent a system of local and regional faults and shear zones, which segregated the area into different tectonic blocks. These sutures have also provided the ways of intrusion for alkaline and basic magmae in the style of a “Rift” structure, housing several carbonatites and impregnations of metal sulphides.The airborne radiometrics obtained many uranium indications by gamma ray spectrometry. However, they led only to disseminated uranium-silicates, associated with syenites, granites and pegmatites, each emanating a characteristic photon energy spectrum. But in general the radiation of thorium prevails, marking northern Madras as a “Thorium Province”.

Notes: In the interpretation of magnetic anomalies and in paleomagnetism, the anisotropy of magnetic susceptibility is commonly neglected. Nevertheless, this property has basic significance, because, owing to susceptibility anisotropy, the directions of the vectors of induced and remanent magnetization are deflected from the direction of the Earth's magnetic field. Almost all rock types investigated possess higher or lower degree of the susceptibility anisotropy. Effusive and sedimentary rocks have the lowest degree of anisotropy. For the latter, the “masking effect” of the paramagnetic mineral components has some influence on the anisotropy degree due to the low mean susceptibility of sedimentary rocks. Metamorphic and plutonic rocks usually exhibit a considerable degree of anisotropy. The highest degree of anisotropy has been found in the rocks containing ferromagnetic minerals with mimetic fabric.The dependence of the degree of the susceptibility anisotropy on the degree of metamorphism proved to be very complicated; of the rock sequence from slates to gneisses, the transient rocks (roofing slates and mica-schist-gneisses) showed the highest degree of anisotropy. This result can be used in geology for reliable determination of these rock types.

Notes: A technique utilizing the convolution theorem is developed to obtain the time-domain electromagnetic response for a number of input pulses from the given step-function response. For illustration an idealized model of a homogeneously conducting non-permeable sphere placed in a uniform field is considered. The nature of the responses due to different types of pulses and their usefulness in estimating the constitution parameter of the sphere are discussed. To show the applicability of the suggested technique to generalized systems, calculations for a conducting permeable sphere are presented in the appendix.

Notes: De préférence, les sismographes seront disposés dans un lieu sans bruit, oú il n'y aurait pas besoin de patternes. Par contre, si les bruits sont tels qu'une patterne est nécessaire, l'objectif de la patterne est d'améliorer le rapport signal/bruit et donc de rendre le signal le plus utile possible. La patterne sera dessinée en fonction des charactéristiques du signal, des charactéristiques du bruit, et de la géologie du site.Il a été démontré que, dans le sens pratique, l'opération optimum sur les données d'une patterne est représentée par le proces “delai et somme”. L'augmentation du nombre N de senseurs sur une surface donnée diminue les espacements entre les senseurs et peut augmenter la coherence entre les bruits enrigistrés aux senseurs voisins, donnant donc moins d'amélioration au rapport signal/bruit que la √N anticipée. L'augmentation du nombre de senseurs par l'augmentation proportionnelle de la surface de la patterne peut resulter en la détérioration du signal, et peut également donner moins d'amélioration que la √N Ces deux effets, ainsi que l'élément économique, combinent à limiter le nombre de senseurs qui peuvent être employés.Bien que les données sur lesquelles l'on a basé ces conclusions soient tirées de la sismologie conventionnelle, ces principes sont également valables pour l'exploration sismique et pour d'autres mesures géophysiques qui emploient des dispositifs dans lesquelles plusieurs senseurs sont requis.