The author, a well-known astronomer himself, describes the evolution of astronomical ideas, touching only lightly on most of the instrumental developments. Richly illustrated, the book starts with the astronomical ideas of the Egyptian and Mesopotamian philosophers, moves on to the Greek period and then on to the golden age of astronomy, that of Copernicus, Galileo, Kepler and Newton. Finally, Pecker concludes with modern theories of cosmology. Written with astronomy undergraduates in mind, this is a fascinating survey of astronomical thinking.

Edith Alicia M ller (1918-1995) was the IAU General Secretary from 1976 to 1979, the first woman to have this responsibility. Many friends, students and colleagues, and others who have met Edith at different occasions, give in this book their memories of her. Her fundamental work in solar physics concerned the chemical composition of the Sun, the time variation of its infra-red spectrum, and its thermal structure. Her interests were, however, far broader than that. She was heavily involved in international work for the teaching of astronomy and for the exchange program of young astronomers.

This is the latest effort in a sequence of presentations begun in 1949 with a series of lectures on long-focus photographic astrometry given by the author as Fulbright professor in Paris at the invitation by the late H. Mineur, at that time Director of the Institut d' Astrophysique. These earlier lectures were published as a series of review articles in Popular Astronomy (1951) and appeared both as Contributions de l'Institut d'Astrophysique, Serie A, No. 81 and as reprint No. 75 of Sproul Observatory. A more elaborate presenta tion was given in 1963 in Stars and Stellar Systems, which was followed by Principles of Astrometry (1967, W. H. Freeman & Co.). During the second half of 1974, again under Fulbright auspices, at the invitation of Pik Sin The, I lectured at the Astronomical Institute in Amster dam, followed by a short course in May-June 1978 at the invitation of E. P. J. van den Heuvel. I gave a more extensive course at the Institut d' As trophysique at the invitation of J. C. Pecker of the College de France and of J. Audouze, Director of the LA.P. Both in Amsterdam and in Paris I had presented occasional astrometric topics at various times. The opportunity to lecture in France and in Holland has facilitated, influenced and improved the organization and contents of the presentations on the subject of long-focus photographic astrometry."

Le ciel est, par-dessus le toit, The sky is, up above the roof, Si bleu, si calme So blue, so calm Un arbre, par-dessus Je toit, A tree there, up above the roof, Berce sa palme. Waves leaves of palm. La cloche, dans le ciel qu'on voit, A church bell, in the sky I see, Doucement tinte. Softly tolls. Un oiseau, sur l'arbre qu'on voit, A bird, upon the tree I see, Chante sa plainte. Sadly calls. PAUL VERLAINE Like Verlaine, we are in prison. The prison is our Earth, "which is so pretty"; our atmosphere and its clouds, its "marvellous clouds." (You would think that Verlaine, Prevert and Baudelaire had been comparing notes ) The sky is up above the roof... A tree there, up above the roof... Stars in the sky, like birds ... their rays, like bells (and here we are with Apollinaire ) What we see opens the way to what we guess at; what we observe Ieads us towards the unobservable. A poem releases images, and the invisible grows big with reality. Astronomcrs are a little like poets (indirectly from the Greek 7tostco, make): they make the universe by interpreting messages, extrapolating spectra, and inventing 'models' of the cosmos or of stars - fictional constructions whose observable part constitutes only a small fraction of the whole, and which only the inductive logic of the theoretician allows us to consider as representing unique physical reality.

Edith Alicia Muller (1918-1995) was the IAU General Secretary from 1976 to 1979, the first woman to have this responsibility. Many friends, students and colleagues, and others who have met Edith at different occasions, give in this book their memories of her. Her fundamental work in solar physics concerned the chemical composition of the Sun, the time variation of its infra-red spectrum, and its thermal structure. Her interests were, however, far broader than that. She was heavily involved in international work for the teaching of astronomy and for the exchange program of young astronomers.

Socrates knew all that was known by his contemporaries. But already in the Middle Ages it was becoming difficult for a single man to have a truly encyclopedic view of all human knowledge. It is true that Pico della Mirandola, Pius II, Leonardo da Vinci, and several other great minds were thoroughly in possession of considerable know ledge, and knew all that one could know, except no doubt for some techniques. The encyclopedists of the 18th century had to be content with an admirable survey: they could not go into details, and their work is a collective one, the specialized science of each collaborator compensating for the insufficiencies of the others. We know very well that our science of today is a science of specialists. Not only is it impossible for anyone person to assimilate the totality of human knowledge, it is impossible even to know ones own discipline perfectly thoroughly. Each year the presses of science pro duce a frightening quantity of printed paper. Even in very limited fields, new journals are created every day, devoted to extremely specialized, often very narrowly defined subjects. It is indeed evident that in a field whose scope extends well beyond astronomical or astrophysical research, it is materially impossible to be informed of everything, even with the richest of libraries at hand.

This is the latest effort in a sequence of presentations begun in 1949 with a series of lectures on long-focus photographic astrometry given by the author as Fulbright professor in Paris at the invitation by the late H. Mineur, at that time Director of the Institut d' Astrophysique. These earlier lectures were published as a series of review articles in Popular Astronomy (1951) and appeared both as Contributions de l'Institut d'Astrophysique, Serie A, No. 81 and as reprint No. 75 of Sproul Observatory. A more elaborate presenta tion was given in 1963 in Stars and Stellar Systems, which was followed by Principles of Astrometry (1967, W. H. Freeman & Co.). During the second half of 1974, again under Fulbright auspices, at the invitation of Pik Sin The, I lectured at the Astronomical Institute in Amster dam, followed by a short course in May-June 1978 at the invitation of E. P. J. van den Heuvel. I gave a more extensive course at the Institut d' As trophysique at the invitation of J. C. Pecker of the College de France and of J. Audouze, Director of the LA.P. Both in Amsterdam and in Paris I had presented occasional astrometric topics at various times. The opportunity to lecture in France and in Holland has facilitated, influenced and improved the organization and contents of the presentations on the subject of long-focus photographic astrometry."

The author, a well-known astronomer himself, describes the evolution of astronomical ideas, touching only lightly on most of the instrumental developments. Richly illustrated, the book starts with the astronomical ideas of the Egyptian and Mesopotamian philosophers, moves on to the Greek period and then on to the golden age of astronomy, that of Copernicus, Galileo, Kepler and Newton. Finally, Pecker concludes with modern theories of cosmology. Written with astronomy undergraduates in mind, this is a fascinating survey of astronomical thinking.

What are the current ideas describing the large-scale structure of the Universe? How do they relate to the observed facts? This book looks at both the strengths and weaknesses of the current big-bang model in explaining certain puzzling data. It arises from an international conference that brought together many of the world's leading players in cosmology. In addition to presenting individual talks, the proceedings of the resulting discussions are also recorded. Giving a comprehensive coverage of the expanding field of cosmology, this text will be valuable for graduate students and researchers in cosmology and theoretical astrophysics.

What are the current ideas describing the large-scale structure of the Universe? How do they relate to the observed facts? This book looks at both the strengths and weaknesses of the current big-bang model in explaining certain puzzling data. It arises from an international conference that brought together many of the world's leading players in cosmology. In addition to presenting individual talks, the proceedings of the resulting discussions are also recorded. Giving a comprehensive coverage of the expanding field of cosmology, this text will be valuable for graduate students and researchers in cosmology and theoretical astrophysics.