Stellar astrophysics still provides the basic framework for deciphering the imprints left over by the evolving universe on all scales. Advances or shortcomings in the former field have direct consequences in our ability to understand the global properties of the latter.

This volume contains the most recent updates on a variety of topics that, though independent by themselves, are inevitably connected on a cosmological scale. These include comprehensive articles by leaders in fields extending from stellar atmospheres through properties of the stellar component in the Milky Way up to the stellar environment in high redshift galaxies.

The wide coverage of astrophysical themes makes this volume very valuable for researchers and Ph.D. students in astrophysics.

The aim of the IV International Symposium on Hamiltonian Systems and Celestial Mechanics, HAMSYS-2001 was to join top researchers in the area of Celestial Mechanics, Hamiltonian systems and related topics in order to communicate new results and look forward for join research projects. For PhD students, this meeting offered also the opportunity of personal contact to help themselves in their own research, to call as well and promote the attention of young researchers and graduated students from our scientific community to the above topics, which are nowadays of interest and relevance in Celestial Mechanics and Hamiltonian dynamics. A glance to the achievements in the area in the last century came as a consequence of joint discussions in the workshop sessions, new problems were presented and lines of future research were delineated. Specific discussion topics included: New periodic orbits and choreographies in the n-body problem, singularities in few body problems, central configurations, restricted three body problem, geometrical mechanics, dynamics of charged problems, area preserving maps and Arnold diffusion.

A revolution similar to that brought by CCDs to visible astronomy is still ahead in IR and submillimeter astronomy. There is certainly no wavelength range which has, over the past several years, seen such impressive advances in technology: large-scale detector arrays, new designs for cooling in space, lightweight mirror technologies. Scientific cases for observing the cold universe are outstanding. Observations in the FIR/Submm range will provide answers to such fundamental questions as: What is the spectrum of the primordial fluctuations? How do primeval galaxies look? What are the first stages of star formation? Most of the international space missions that have been triggered by these questions are presented in detail here. Technological issues raised by these missions are reviewed, as are the most recent achievements in cooling and detector technologies.

The area of diffuse astrophysical media is enormous and ranges over circum stellar to extragalactic scales. The physical conditions can vary from cool dusty gases to collections of relativistic particles. Flows in such media are set up by en ergy and momentum injection from winds, jets and explosions. The study of these phenomena involves physics, chemistry and, inevitably, hydrodynamics. One of the most important aspects of this study is the ever increasing overlap between theory and observation. Indeed, it can be argued that the only way to really understand these complex flows which can never be duplicated under terrestrial conditions, is to encourage this overlap, and this was one major aim of this Conference. Because of the long theoretical and observational association of the Manchester Group with this general area, Manchester seemed an appropriate venue for this Con ference. But in fact this long association and the actual year of the Conference are connected. In 1951 Franz Kahn joined the Astronomy Department at Manchester University and immediately the study of diffuse media, particularly the hydrody namic aspects, commenced and has flourished ever since. Franz became Head of the Astronomy Department in 1981 following the retirement of Professor Z. Kopal, who founded the Department and was instrumental in attracting Franz to it. In 1993, Franz retired from this position and a most serendipidous coincidence was his election to the Royal Society announced shortly before the Conference.

The mystery of the diffuse interstellar bands has been variously a curiosity, a co nundrum, and a nuisance for astronomers in the seven decades since the features were first noticed, but recently they have become a forefront issue in astrophysics. Ever since Paul Merrill, in a series of papers starting in 1934, pointed out the interstellar and unidentified nature of the bands, a Who's Who of twentieth century astronomers have tried their hands at solving the problem of identifying the carriers. Henry Norris Russell, Pol Swings, Otto Struve, Paul Ledoux, W. W. Morgan, Walter Adams, Jesse Greenstein, Lawrence Aller, and Gerhard Herzberg all briefly entered the stage, only to move on quickly to other problems where the chances for progress appeared more realistic. In more recent times a number of equally prominent scientists have pursued the bands, but generally only as a sideline to their real astronomical research. But in the past decade, and particularly in the past three years, the view of the search for the diffuse band absorbers as an interesting but perhaps quixotic quest has changed. Today there are several astronomers, as well as laboratory chemists, who are devoting substantial research time and resources to the problem and, as perhaps the most reliable indicator of the newly elevated status of research in this field, some research grants have now been awarded for the study of the bands.

The present volume, the fourth one in the "Space Sciences Series of ISSI" (Inter national Space Science Institute), contains the proceedings of a workshop on "Pri mordial Nuclei and Their Galactic Evolution", which was held at ISSI in Bern on 6-10 May 1997. This topic was chosen following some general enquiries with the scientific community concerning its desirability and timeliness. Five convenors, D. Duncan, C. Hogan, J. Linsky, N. Prantzos, and H. Reeves (chair) subsequently set up the workshop, nominated a list of invitees, structured the workshop into a series of introductory talks and into six topical working groups (early Universe extragalactic objects -low-Z stars - galactic disk and galactic evolution - solar nebula -local interstellar medium), and described the tasks of the working groups in a list of keywords. It is the main task of ISSI to bring together space scientists, ground-based observers, and theorists from different fields and to give them the opportunity to discuss and compare their results, thus contributing to the achievement of a deeper understanding, adding value to those results through multi-disciplinary research in an atmosphere of international co-operation. In that spirit the convenors selected participants working in fields ranging from Big Bang theory to observers oftoday's Solar System, thus spanning the widest possible range both in time and space.

Massive stars occupy an exceptional place in general astrophysics. They trigger many if not all of the important processes in galactic evolution whereas due to their intrinsic brightness, they offer the (only until now) possibility to study the stellar content and stellar behaviour in distant galaxies. The last, say, 25 years, massive stars have been the subject of numerous meetings discussing the influence of massive stars on population synthesis, the number distribution of different types of massive stars, the LBV phenomenon, WR stars, X-ray binaries, stellar winds in massive stars, chemical pecularities in massive stars, supernova explosions of massive stars and the important SN1987A event, the influence of massive stars and chemical evolution of galaxies. It is clear that without a theory of stellar evolution, the study of these topics loses a lot of its significance. Massive star evolution therefore got a chance in these meetings, but rarely as a prime subject. The state of the art, the physical processes and the uncertainties in stellar evolution were barely touched. Even more, the influence of close binaries in all these massive star meetings slowly disappeared the last, say, 13 years without any scientific justification, although a significant fraction of stars occurs in close binaries with periods small enough so that both components will interact during their evolution. Denying the binaries or not discussing their influence on results and conclusions, makes the latter very uncertain or even completely unreliable.

Living material contains about twenty different sorts of atom combined into a set of relatively simple molecules. Astrobiologists tend to believe that abiotic mater ial will give rise to life in any place where these molecules exist in appreciable abundances and where physical conditions approximate to those occurring here on Earth. We think this popular view is wrong, for it is not the existence of the building blocks of life that is crucial but the exceedingly complicated structures in which they are arranged in living forms. The probability of arriving at biologically significant arrangements is so very small that only by calling on the resources of the whole universe does there seem to be any possibility of life originating, a conclusion that requires life on the Earth to be a minute component of a universal system. Some think that the hugely improbable transition from non-living to living mat ter can be achieved by dividing the transition into many small steps, calling on a so-called 'evolutionary' process to bridge the small steps one by one. This claim turns on semantic arguments which seek to replace the probability for the whole chain by the sum of the individual probabilities of the many steps, instead of by their product. This is an error well known to those bookies who are accustomed to taking bets on the stacking of horse races. But we did not begin our investigation from this point of view.

The astronomer Jan Hendrik Oort (1900-1992) left behind an extensive collection of notes and correspondence, both on his research and on matters that concerned him in a variety of official functions. Upon Oort's death, the collection was augmented by more personal papers, letters, journals, and diaries. The resulting collection forms a rich source of information on many aspects of twentieth-century astronomy, in which Oort played such an important role. The scientific and personal material covers the entire span of time from Oort's early youth until his death. To make these papers accessible to a wide circle of users, the collection has now been catalogued and described; the result is presented in this volume. A name index and a subject index have been added to facilitate access. The inventory is accompanied by a short biographical sketch, and a number of photographs, mostly relating to Oort's career as a scientist. The original papers themselves are archived in the Leiden University Library.

In May 1976, when one of us was temporarily associated with Stras bourg Observatory for lecturing on distance determination methods (Heck 1978), Pierre Lacroute - then in his last year as Director there - mod estly requested comments on a project he had been cherishing for quite a few years, and which he had been presenting to visitors and colleagues: an astrometric satellite. His persuasiveness and persistence won support from the scientific com munity, from the French space agency CNES and from the European Space Agency (ESA): the Hipparcos satellite was born. It was fitting that Lacroute lived long enough after his retirement to attend the launch of his brainchild in 1989 and to see it successfully operational. He knew however he would not enjoy the completion of this long and ambitious mission (he passed away on 14 January 1993, a few days before reaching the age of 87). In May 1997, in the prestigious setting of San Giorgio :Maggiore in Venice, ESA organized a symposium celebrating the presentation of the Hipparcos and Tycho catalogues. That conference signalled also the re lease of the first scientific results based at least partially on Hipparcos data. An impressive proceedings volume (Battrick 1997) of more than nine hundred pages, gathering together almost two hundred contributions, gave evidence of numerous studies in progress, in addition to papers starting to appear in the classical journals. The well-maintained ESA Hipparcos web site (http://astro. estec. esa.

This book reveals the remarkable revolution which has occurred in infrared astronomy in recent years as the result of technology breakthroughs in the development and availability of tiny imaging devices known as arrays'. The book contains the proceedings of a conference at the University of California, Los Angeles in July 1993 at which about 300 participants from all over the world met to discuss the progress and astronomical applications of infrared array detectors. A key feature of the book is the mix of papers describing the detector technology, astronomical instruments or observational methods, with those describing the latest, exciting astrophysical conclusions based on measurements made with the new arrays. In many cases, the images and spectra shown were spectacular, and it was difficult to appreciate that the results were for infrared rather than optical wavelengths. Astronomers, instrument designers and representatives of the infrared detector industry were all present. Reviews of the state-of-the-art in near infrared imaging and spectroscopy and mid-to-far infrared imaging and spectroscopy from ground-based observatories are mixed with reviews of planned space missions such as HST-second generation instruments, ISO, and SIRTF. Prospects for IR astronomy from Antarctica are also described. Finally, the first infrared astronomical science from the 10-m W.M. Keck Telescope is described. Also, numerous astronomical results and new instrumentation ideas are summarized in over 100 poster papers. This book provides an invaluable reference work and an excellent introduction for all astronomers to the rapidly growing field of infrared astronomy. Scientific topics range from studies of solar system objects to galaxies at very high redshifts, and include almost everything in between e.g., star forming regions, the Galactic Center, globular clusters, starburst galaxies and cosmology. Only a few years ago none of these studies would have been possible.

th The 4 ESO CCO Workshop, Optical Detectors for Astronomy, was held during September 13-16, 1999 at its usual location, the headquarters of the European Southern Observatory in Garching, Germany. We prefer to remember this workshop as a "meeting of friends", who came to Garching to visit ESO and to present their work, rather than a formal meeting. Based on our experience with the 1996 ESO CCO workshop, we deliberately put emphasis on creating an environment that encouraged the participants to stay together and informally exchange ideas. These informal events began with a tour of the BWM auto factory and continued with a reception at "SchloB Beletic", the conference dinner at a real SchloB of the Bavarian International School (where the participants enjoyed basket, baseball, table soccer, rock climbing and eventually dancing) and concluded with a tour of the Paulaner Brewery and dinner at the Seehaus in the Englisher Garten. The lunch "Biergarten", adjacent to the poster session area, was a daily meeting point. The result was a good mixture of excellent presentations and posters, collected in these Proceedings, and many occasions for people to get in touch and to have fun together, as witnessed by the selection of workshop pictures that we randomly placed between papers. This book contains a special contribution.

In recent years aperture synthesis and interferometry have become very powerful tools in radioastronomy. Investigation of distant galaxies, for example, have revealed structures with sizes of less than a kiloparsec. In general, the study of galaxies has benefited from the great power of these techniques. Radar applications have also dramatically increased their quality by using the interferometry principle. Tracking and airborne radar can now determine position and velocity of objects with a much higher accuracy. This book describes in the first six, short chapters the basics of interferometry and aperture synthesis. The following two, long chapters treat the aspects of radioastronomical interferometers and radar applications of interferometry in great detail. The text offers readers a very good opportunity to familiarize themselves with the mathematical background of these very complex techniques. For researchers and students in radioastronomy and electrical engineering.

A hands-on introduction to machine learning and its applications to the physical sciences As the size and complexity of data continue to grow exponentially across the physical sciences, machine learning is helping scientists to sift through and analyze this information while driving breathtaking advances in quantum physics, astronomy, cosmology, and beyond. This incisive textbook covers the basics of building, diagnosing, optimizing, and deploying machine learning methods to solve research problems in physics and astronomy, with an emphasis on critical thinking and the scientific method. Using a hands-on approach to learning, Machine Learning for Physics and Astronomy draws on real-world, publicly available data as well as examples taken directly from the frontiers of research, from identifying galaxy morphology from images to identifying the signature of standard model particles in simulations at the Large Hadron Collider. Introduces readers to best practices in data-driven problem-solving, from preliminary data exploration and cleaning to selecting the best method for a given task Each chapter is accompanied by Jupyter Notebook worksheets in Python that enable students to explore key concepts Includes a wealth of review questions and quizzes Ideal for advanced undergraduate and early graduate students in STEM disciplines such as physics, computer science, engineering, and applied mathematics Accessible to self-learners with a basic knowledge of linear algebra and calculus Slides and assessment questions (available only to instructors)

A wealth of material on practically every aspect of astronomy, beginning from the first principles. It is quite unique in providing a level of scientific accuracy and detail to be found in no other introductory book, including coverage of instruments, theory, observation, space exploration and cosmology. Encyclopaedic in its breadth, the book still contains in-depth explanations of the underlying theories. The illustrations - many of them colour photographs - animate the text, itself so clear and concise that it will fascinate readers of every discipline.
Winner of the Rapportryers Prize for "most meritorious popular science book."

An atmospheric phenomenon is considered as 'explained' when we have succeeded in deducing it on the basis of accepted principles of physics. (H. Ertel, Methods and problems of dynamical meteorolo gy,p. l) Until recently, noctilucent clouds were regarded merely as a curious atmos pheric phenomenon, the occurrence of which aroused only limited scientific attention. However, in the last two decades the interest they have been given has markedly increased. The clouds, usually pale blue in colour, may be seen on a clear night at high latitudes. Typical examples are illustrated in the book. Clouds looking like these in daytime would be classified as cirrostratus. What sets noctilucent clouds apart is their occurrence in the middle of the night, their very obvious pale blue colour, and their disappearance into the dawn close to the onset of civil twilight when the Sun is 6 Degrees below the horizon. as being set apart from ordinary Noctilucent clouds were first recognized clouds in 1884/1885 and in a series of sightings that followed their return in the summer of 1885. That year marked the beginning of observations and the interpretation of twilight phenomena. The impetus came from the extraordi nary Krakatoa eruption, which was not only one of the most spectacular volcanic eruptions in recorded history, but which also turned out to be a startling event in atmospheric science with repercussions even in our time.

Magnetic Fields play a key role in the physics of star formation on all scales: from the formation of the large complexes of molecular clouds to the formation of solar-like planetary systems. The plasma physics involved is non-linear and very complex, which requires the development of large numerical codes. An additional difficulty is that the detection and study of magnetic fields is not easy from an observational point of view, and therefore theoretical models cannot easily be constrained.

In the week from April 21st to 25th in 2003, a meeting was held on the Campus of the Universidad Complutense de Madrid (Spain) to join theoretical and observational efforts to address these issues. The objective was to define a set of relevant problems for the physics of star formation that can be properly addressed with the current or near-future instruments.

This book summarizes the results of this intensive week of work. The book is written in a comprehensive manner and reviews our current knowledge of the subject. It also represents an updated account of the ideas and thoughts of the scientists working in the field of Star Formation. The contributions are presented in six chapters which correspond to the six fundamental issues (sessions) on which the discussion was focused during the workshop: the physics of turbulence in the Interstellar Medium (ISM), the formation of structure in the ISM, the formation of stars within dense cores of molecular gas, the physics of accretion disks, the physics of outflows and their interaction with the ISM, and the interaction between the stellar magnetosphere and accretion disk.

Each chapter starts with a comprehensive summary written by one of the editors, which includes input from the contributions as well as the editor's own thoughts on the subject. For all these reasons the book is well-suited as a primer to introduce graduate students in the richness of this field of research.

Particle physics seems to be entering a new period of consoli- dation. In 1977 when the first summer institute on particles and fields was held at the Banff Center, the standard model of the electro-weak interaction was a promising model more or less con- firmed; today it seems quite well-confirmed. QCD was considered as probably the correct theory of strong interactions; today most theo- rists take it for granted. What seems to be lacking are computa- tional tools and strenuous experimental testing; the major ideas seem to exist. Thus, this is a particularly auspicious time for a review of the status of theoretical and experimental particle physics and field theory. The lectures collected in this volume were presented from August 16 to August 27, 1981 at the Banff Center in Banff, Canada. The unifying theme was gauge fields and the topics covered dealt with electro-weak interactions, Q.C.D., sub-quarks and unified theories. The format of the Institute was as follows: thirteen lecture series of two to four hours each given by S. Brodsky, D. Bryman, M. Chen, S. Coleman, M. Creutz, H. Harari, J. Iliopoulos, C.H. Llewellyn- Smith, P. Lepage, D. Perkins and L. Susskind. In addition there were nine seminars (one hour each) given by G. Bodwin, G. Bunce, M.

The Hipparcos satellite, developed and launched by the European Space Agency (ESA) in 1989, was the first space mission dedicated to astrometry - the accurate measurement of positions, distances, and proper motions of stars. Amongst the key achievements of its measurements are refining the cosmic distance scale, characterising the large-scale kinematic motions in the Solar neighbourhood, providing precise luminosities for stellar modelling, and confirming Einstein's prediction of the effect of gravity on starlight. This authoritative account of the Hipparcos contributions over the following decade is an outstanding reference for astronomers, astrophysicists and cosmologists. It reviews the applications of the data in different areas, describing the subject and the state-of-the-art before Hipparcos, and summarising all major contributions to the topic made by Hipparcos. It contains a detailed overview of the Hipparcos and Tycho Catalogues, their annexes and their updates. Each chapter ends with comprehensive references to relevant literature.

The Energetic Gamma-Ray Experiment Telescope (EGRET) instru ment on the Compton Gamma-Ray Observatory left as a legacy its Third Catalog of High Energy Gamma-Ray Sources, whose detections include a large number of blazars, some pulsars, the Large Magellanic Cloud and a solar flare. Most of the newly discovered objects - a majority of the catalog -are unidentified sources, with a clearly predominant Galactic population. Are all these radio-quiet pulsars, like Geminga, or is there a novel type of celestial object, awaiting identification? In spite of the limited angular resolution provided by EGRET and COMPTEL, there is still much to learn about unidentified ,-ray sources: correlation studies, multiwavelength observations and theoretical work can provide valuable clues, specially if these efforts are carried out in a coordinated manner. The aim of this workshop, held from October 9 to 11, 2000, at the Instituto N acional de Astrofisica, Optica y Electronica, at Tonantzintla, Mexico, was to gather experts on the subject, including observational as tronomers specialized in other regions of the electromagnetic spectrum, in an effort to address the question of the Nature of Galactic high-energy gamma-ray sources, both from the theoretical and observational perspec tive, and elaborate schemes for future identification studies which can make use of existing and forthcoming facilities.

TH. HENNING and B. STECKLUM University Observatory. Jena This workshop was organized by the University Observatory Jena and devoted to the physics and chemistry of dense regions of interstellar matter. It was especially dealing with the properties of interstellar dust grains and star formation in those regions. This field of research was opened in Jena already in the 1950s and an early fA U Colloquium on the topic of interstellar matter was held here in 1969. Since that time, the subject of interstellar matter has grown into a much more important part of astrophysics than it was in 1969. Now we are beginning to understand the process of star formation in a greater detail. The discovery of many interstellar molecules by radioastronomers opened the new field of interstellar chemistry. In addition, the application of the new techniques of infrared astronomy led to the discovery of several absorption bands, e. g. , the 3. 1 11m ice band, which pointed to the existence of grain mantles. More recently, the detection of infrared emission lines was the first hint to the existence of a new component of interstellar matter. All these things were discussed extensively during the workshop. The very successful IRAS mission, which was also a subject of this workshop, gave us many new insights and unexpected findings, e. g. , the detection of infrared cirrus clouds.

The reader will find in this volume the Proceedings of the NATO Advanced Study Institute held in Cortina d'Ampezzo, Italy between August 6 and August 17, 1990 under the title "Predictability, Stability, and Chaos in N-Body Dynamical Systems". The Institute was the latest in a series held at three-yearly inter vals from 1972 to 1987 in dynamical astronomy, theoretical mechanics and celestial mechanics. These previous institutes, held in high esteem by the international community of research workers, have resulted in a series of well-received Proceedings. The 1990 Institute attracted 74 participants from 16 countries, six outside the NATO group. Fifteen series of lectures were given by invited speakers; additionally some 40 valuable presentations were made by the younger participants, most of which are included in these Proceedings. The last twenty years in particular has been a time of increasingly rapid progress in tackling long-standing and also newly-arising problems in dynamics of N-body systems, point-mass and non-point-mass, a rate of progress achieved because of correspondingly rapid developments of new computer hardware and software together with the advent of new analytical techniques. It was a time of exciting progress culminating in the ability to carry out research programmes into the evolution of the outer Solar 8 System over periods of more than 10 years and to study star cluster and galactic models in unprecedented detail.

In the course of editing this volume I discovered that I am temper amentally unsuited to the task, an impediment that in no small way accounts for the fact that its publication is later than I would have hoped or anticipated. I am, at heart, a pedant, particularly with respect to the use and abuse of the English language. Many of my scientific colleagues are a good deal less punctilious; they take the reasonable view that if the message is clear, the manner of expression is unimportant. Experience has taught me that what is clear to the author is often quite unclear to the reader unless the author takes the trouble to express himself with precision. I have also found that most scientists are unwilling to devote to the presentation of their results the care that they lavish on obtaining them. But I found myself slipping beyong this often justifiable complaint into a state of inexcusable self-righteousness. It began innocently enough. Conscious of the need for speed, I read the first two or three texts with murmurs of approval, and scribbled 'no changes needed' on the title page of the copy. Then I began to notice one or two grammatical mistakes, plural verbs with singular nouns, mixtures of tenses, and so on, which had to be corrected; not serious, I told myself, a matter only of changing a word here, retyping a line there. Quickly I sank deeper."

Long-term measurements of field strength have been performed over a 160 km path entirely over sea in the Baltic area. For short periods the radio measurements have been combined with meteorolo- gical measurements in order to describe the structure of the re- fractive index field. The heigth of layers was continously deter- mined by remote sensing techniques and their thickness and inten- sity by airborne and balloonborne instruments. From these data, field strengths have been calculated for scatter, reflection and duct propagation. It will be shown that reflection propagation dominates at the low frequency end. Whilst at higher frequencies, very sharp layers are required for reflection propagation. At these frequencies, high signals are generally caused by duct propagation. 1.1 Instruments and plan for the experiments. The radio measurements were performed with the following equipment. 5000 MHz: Transmitted power 500 kW (pulsed). Reflector antennas. Free space field strength over the path + 15 dBm. 460 MHz: Transmitted power 10 W (CW) 8 element Yagi antennas. Free space field strength over the path - 65 dBm. 170 MHz: Transmitted power 10, W(CW). 8 element Yagi antennas. Free space field strength over the path - 60 dBm. The antenna heights for the transmitters and receivers were 100 m above sea level. The field strengths were recorded on ink recorders and simul- taneously sampled, digitized and evaluated on line in a minicom- puter. For the meteorological measurements, the following equipment were used: Airborne microwave refractometer and thermistor, flown up to 2000 m.

This book gathers the proceedings of a symposium on Dynamics of satellites which took place in Prague in May 1969 during the twelfth COSPAR meeting. This symposium was sponsored by the International Astronomical Union, the International Association of Geodesy, the International Union of Theoretical and Applied Mechanics and COSPAR (Committee on Space Research). The organizing committee was composed of Dr. KOVALEVSKY chair man, Dr. Yu. V. BATRAKOV representing IAU, Dr. A. H. COOK for lAG, Dr. D. KING-HELE for COSPAR, Prof. M. Roy for IUTAM and Dr. ROSENBERG. I wish to take advantage of the opportunity to thank, on behalf of all the participants, the organizing committee members, Prof. BUCHAR, Dr. RAJSK: I and Dr. SEHNAL, for the kindness and efficiency of their welcome. The interpreters who translated with virtuosity during the whole symposium also deserve our gratitude. I am grateful also for the care and skill with which Springer-Verlag has printed this volume."