In Small Astronomical Observatories, Patrick Moore has collected descriptions of amateur and small professional observatories currently in use in Europe and America, showing how many astronomers have built their own observatory, often with effective and sometimes extraordinary improvisations to reduce the cost. There is a photograph of each, along with details of its construction and a foreword written by Patrick Moore. In addition to providing a fascinating study for its own sake, Small Astronomical Observatories offers a unique fund of ideas and practical details for anyone who wants to build an amateur or small professional observatory.

Magnetism is one of the basic properties of matter. Mankind has trav­ elled a long road in discovering and utilizing magnetism, and in this respect the ancient Chinese people have made outstanding contribu­ tions. In the book 'Lu's Spring and Autumn', written near the end of the Warring States Period, i. e. in the third century B. C. , there is a statement on the "attraction of iron by lodestones". So at that time it was known that magnets can attract ferromagnetic material. At the be­ ginning ofthe first century A. D. , viz. in the early years ofthe East Hang Dynasty, the famous scholar Wang Chong wrote in his masterpiece 'Len Hen' that the handle of a magnetic dipper pointed to the south. It was thus discovered at the time that magnets can point to the poles of the geomagnetic field. At the beginning of the twelfth century, during the reign of Emperor Hui of the Sung Dynasty, in the two books written by Zhu Yo and Xu Jin, respectively, there are descriptions of the com­ pass used in navigation. This tells us that the application of compasses was rather widespread at that time. The distinguished scientist Sen Go (1031-1085) discovered the declination of the terrestrial magnetic field. This is four hundred and more years earlier than its discovery by Christopher Columbus in 1492 during his voyage across the Atlantic Ocean. Such facts as these manifest the important contributions of ancient China to global civilization.

Solar flares are very complex electromagnetic phenomena of a cataclysmic nature. Particles are accelerated to very high velocities and a variety of physical processes happen inside and outside flares. These processes can be studied by a large number of techniques from Earth and from space. The aim is to discover the physics behind solar flares. This goal is complicated because information about the flare mechanism can be obtained only in an indirect way by studying the secondary effects.

One of the most spectacular discoveries of molecular astronomy has been the detection of maser emission. The same radiation that is generated in the laboratory only with elaborate, special equipment occurs naturally in interstellar space. This intense radiation probes the smallest structures that can be studied with radio telescopes. By a fortunate coincidence maser radiation is generated in both star forming regions and the envelopes of late-type stars. The early and late stages in the life of a star are considered to be the most interesting phases of stellar evolution. Maser emission has also been detected in external galaxies.

It is the customary practice to report the major events of a General Assembly -the Invited Discourses, Joint Discussions and Joint Commission Meetings in Highlights of Astronomy. Vol. 8 reports the highlights of the XXth General Assembly of the International Astronomical Union, 1988 August 2-11, Baltimore, USA. The present volume contains the 3 Invited Discourses and papers presented at 7 Joint Discussion Meetings and 6 Joint Commission Meetings. Two Joint Commission Meetings will be reported elsewhere -JCM5 Spectroscopy of Individual Stars in Globular Clusters and the Early Chemical Evolution of our Galaxy (in summary only here, published by the Imprimerie de l'Observatoire de Paris) and JCM7 Star Clusters in the Magellanic Clouds (see Transactions of the IAU, Vol.XXB, report of Commission 37). I am most grateful to the authors of the invited discourses R.M. West and V.I. Moroz, M. Schmidt and M. Rees for sending me the manuscripts so promptly. I am also indebted to the Chairmen of the Joint Discussion and Joint Commission Meetings for their organisation of the meetings and for the assembly of their material for publication. Unfortunately the deadline for receipt of manuscripts coincided with an extended postal strike in France which seriously hindered the preparation of the volume for publication.

In recent years there have been many attempts to use simple energy balance models to simulate the climatic changes that occurred during the Pleistocene by altering the earth's energy budget through sma 11 orb ita 1 element changes. Attempts with mean annual models which resolved latitudinal variation in tem- perature failed to produce large ice sheets when the obliquity was changed a few degrees (1,2) although these early models were generally more sensitive than today's parameterizations would suggest. Attention then turned to seasona 1 energy balance models, since the primary insolation anomaly is seasonal. Sel- lers (3), Thompson and Schneider (4) and North and Coakley (5) developed simple models which were either effectively zonally averaged or included a separate land and ocean surface tempera- ture at each latitude. Suarez and Held (6) added some vertical resolution in their model. All included the ice-albedo feedback mechanism and horizontal transport which was essentially diffu- sive. The models shared one interesting property : they remai- ned rather insensitive to the sizes of orbital changes which were thought to have occurred in the Pleistocene. There were minor differences in the results and some pointed toward possi- ble ways out of the puzzle but curiously the mechanisms of ice- -albedo feedback in the insolation and water vapor feedback in the infrared terms ·seemed too weak to account for the ice ages (for a review of these models see (7) and more recently (8)).

"Meteoric phenomena" is the accepted term for the complex of physi­ cal phenomena that accompany the entry of meteoric bodies into the at­ mosphere of the earth (or of any planet). "Meteoric bodies" are usually defined as cosmic bodies observed by optical or radar techniques, when they enter the atmosphere. The limiting sensitivity of present-day radar equipment makes it possible to record meteors of up to stellar magnitude +14, while the most brilliant bolides may reach magnitude -19. On a mass 7 7 scale this corresponds approximately to a range of 10- to 10 g. How­ ever, met~or astronomy is also concerned with larger objects, namely crater-forming meteorites, or objects that cause large-scale destruction when they arrive through the atmosphere (an example is the Tunguska River meteorite). Consideration of the interaction of such objects with 12 the terrestrial atmosphere extends the mass range to 10 g. On the other hand, scientists studying fragmentation processes in meteoric bod­ 7 ies have to consider particles with masses less than 10- g, and the use of data from meteoric-particle counters on rockets and artificial satel­ lites, from microcraters on the lunar surface, and from noctilucent clouds 12 lowers the minimum mass to 10- g. Therefore, the mass range of meteoric bodies, or meteoroids, encompasses 24 orders of magnitude. Although recent years have witnessed considerable development in meteor research, both in the Soviet Union and elsewhere, the main mono­ graphs on meteor physics were published twenty or more years ago.

IAU Symposium Number 52 on Interstellar Dust and Related Topics was held at Albany, N.Y., on the campus of the State University of New York at Albany from May 29 to June 2, 1972. The members of the Organizing Committee were: Dr A. D. Code, University of Wisconsin, Madison, Wis., U.S.A. Dr B. D. Donn, Goddard Space Flight Center, Greenbelt, Md., U.S.A. Dr A. Elvius, Stockholm Observatory, Saltsjobaden, Sweden. Dr T. Gehrels, Lunar and Planetary Laboratory, University of Arizona, Tucson, Ariz., U.S.A. Dr J. M. Greenberg (Chairman), State University of New York at Albany, Albany, N.Y., U.S.A. Dr H. C. van de Hulst, Sterrewacht, Leiden, Holland. Dr S. B. Pikel'ner, Sternberg Astronomical Institute, Moscow, U.S.S.R. Dr E. E. Sal peter, Cornell University, Ithaca, N.Y., U.S.A. Dr B. E. Turner, National Radio Astronomy Observatory, Charlottesville, Va., U.S.A. The suggestion was first made in 1971 that a symposium on interstellar grains would be timely. The response to the first preliminary announcement, which was sent out on November 29, 1971, was well beyond our expectations. The meeting was locally sponsored by the State University and by Dudley Observatory. The National Aeronautics and Space Administration and the National Science Foundation con­ tributed along with the JAU. There were 158 participants of whom 49 were from 15 countries outside the United States. A total of 92 papers were presented.

Microscopy plays an integral role in the research and development of new medicines. Pharmaceutical Microscopy describes a wide variety of techniques together with numerous practical applications of importance in drug development. The first section presents general methods and applications with an emphasis on the physical science aspects. Techniques covered include optical crystallography, thermal microscopy, scanning electron microscopy, energy dispersive x-ray spectrometry, microspectroscopy (infrared and Raman), and particle size and shape by image analysis. The second section presents applications of these techniques to specific topics of pharmaceutical interest, including studies of polymorphism, particle size and shape analysis, and contaminant identification. Pharmaceutical Microscopy is designed for those scientists who must use these techniques to solve pharmaceutical problems but do not need to become expert microscopists. Consequently, eachsection has exercises designed to teach the reader how to use and apply the techniques in the book. Although the focus is on pharmaceutical development, workers in other fields such as food science and organic chemistry will also benefit from the discussion of techniques and the exercises.

Proceedings of Symposium No. 47 organized by the IAU held in Newcastle upon Tyne, England, March 22-26, 1971

THE MOON IX PREFACE TO THE SPRINGER EDITION When this collection of Babylonian astronomical purpose of column of the lunar ephemerides (by texts was published in 1955 (a date omitted by Aaboe) and the explanation of the method of computing the eclipse text ACT No. 6o (by Hamilton mistake from the title page), it contained all texts of this type that I could lay my hands on. As was to be and Aaboe). Some of these advances I have tried to incorporate into my History of Ancient Mathematical expected, the past 25 years provided more fragments, identified by A. Sachs and A. Aaboe in the British Astronomy (1975), which should be used as a guide to Museum and listed below. Also, some new joins the more recent literature. could be made and some errors of mine corrected. My sincerest thanks go to Springer-Verlag for Nevertheless, I think one still can consider the making this work again available to students of material of 1955 to be representative of what has been ancient astronomy. The Institute for Advanced preserved of the mathematical astronomy of the Study, which together with Brown University has Seleucid period. supported my work for more than four decades, has In the meantime, far more progress has been made graciously given its permission for this reprint. in our understanding of Babylonian astronomy, mainly by the publications of Aaboe, Hamilton, Maeyama, Sachs, van der Waerden, and others. As an Princeton 0.

MOHAMMAD ASADZADEH, PHD is Professor of Applied Mathematics at the Department of Mathematical Sciences, Chalmers University of Technology and University of Gothenburg. His primary research interests include the numerical analysis of hyperbolic pdes, as well as convection-diffusion and integro-differential equations.

lgebraic Identification and Estimation Methods in Feedback Control Systems presents a model-based algebraic approach to online parameter and state estimation in uncertain dynamic feedback control systems. This approach evades the mathematical intricacies of the traditional stochastic approach, proposing a direct model-based scheme with several easy-to-implement computational advantages. The approach can be used with continuous and discrete, linear and nonlinear, mono-variable and multi-variable systems. The estimators based on this approach are not of asymptotic nature, and do not require any statistical knowledge of the corrupting noises to achieve good performance in a noisy environment. These estimators are fast, robust to structured perturbations, and easy to combine with classical or sophisticated control laws.

Provides a smooth and pleasant transition from first-year calculus to upper-level mathematics courses in real analysis, abstract algebra and number theory Most universities require students majoring in mathematics to take a “transition to higher math” course that introduces mathematical proofs and more rigorous thinking. Such courses help students be prepared for higher-level mathematics course from their onset. Advanced Mathematics: A Transitional Reference provides a “crash course” in beginning pure mathematics, offering instruction on a blendof inductive and deductive reasoning. By avoiding outdated methods and countless pages of theorems and proofs, this innovative textbook prompts students to think about the ideas presented in an enjoyable, constructive setting.

An introduction to technical details related to the Physical Layer of the LTE standard with MATLAB®
The LTE (Long Term Evolution) and LTE-Advanced are among the latest mobile communications standards, designed to realize the dream of a truly global, fast, all-IP-based, secure broadband mobile access technology.