The aim of this book is to bridge the gap between the pure instrumental physicist and the user of detectors and spectrometers. The essential parameters describing the performance of these devices are identified and the designs of a wide variety of practical instruments are illustrated working on topical problems. The author has spent 14 years designing and applying spectrometers in the visible and near infra-red domains predominantly to investigate gaseous nebulae. Most recently he has designed for instance a large (15 x IS-in.) Ha interference filter for the SRC, 48-in. Schmidt camera, insect-eye Fabry-Perot spectrographs, image tube filter cameras, a SISAM monochromator, a three-beam Fabry-Perot monochromator (collaboratively) for the ISO-in. Anglo-Australian telescope and a two-etalon PEPSIOS type monochromator. Consequently emphasis in this book is placed on devices useful from the ultra-violet to the infra-red. Likewise many of the illustrations are drawn from astronomy. However most of the ideas that are presented invariably have applications in other branches of science and wavelength domains.

A tutorial introduction to the field of dye lasers, Dye Laser Principles also serves as an up-to-date overview for those using dye lasers as research and industrial tools. A number of the issues discussed in this book are pertinent not only to dye lasers but also to lasers in general. Most of the chapters in the book contain problem sets that expand on the material covered in the chapter. - Dye lasers are among the most versatile and successful laser sources currently available in use Offering both pulsed and continuous-wave operation and tunable from the near ultraviolet to the near infrared, these lasers are used in such diverse areas as: industrial applications, medical applications, military applications, large-scale laser isotope separation, fundamental physics, spectroscopic techniques, laser radar

Written by a recognized expert in the field, this clearly presented, well-illustrated book provides both advanced level students and professionals with an authoritative, thorough presentation of the characteristics, including advantages and limitations, of telescopes and spectrographic instruments used by astronomers of today. - Written by a recognized expert in the field - Provides both advanced level students and professionals with an authoritative, thorough presentation of the characteristics, including advantages and limitations, of telescopes and spectrographic instruments used by astronomers of today

The 19th ESLAB Symposium on 'The Sun and the Heliosphere in Three Dimensions' was held in Les Diablerets (Switzerland) on 4-6 June 1985. Organised almost exactly ten years after the Goddard Space Fl i ght Center Sympos i um dea 1 i ng with the Sun and the i nterp 1 anetary medium in three dimensions, the aim of this Symposium was not only to review the progress made in understanding the three-dimensional structure and dynamics of the heliosphere, but also to look ahead to the scientific return to be expected from the Ulysses mission. Scheduled for launch in May 1986, the scientific instrumentation on board Ulysses will shed light on the conditions and processes occurring away from the ecliptic plane, thereby adding literally a new dimension to our understanding of the only stellar plasmasphere to which we have direct access. The scientific programme of the Symposium was built around a series of invited review papers dealing with aspects of the corona and its influence on the interplanetary medium via transient ejecta, the solar wind, energetic solar particles and galactic cosmic rays, interplanetary dust and neutral gas. These invited talks were supplemented by a number of contributed and poster papers. With the exception of three contributed talks and Wibberenz' review of coronal and acceleration of energetic particles, all papers propagation presented at the Symposium are included in this volume.

Problems associated with a general scarcity of observations of the southern sky have persisted since the present era of galactic research began some sixty years ago. In his 1930 Halley Lecture A. S. Eddington commented on the observational support given to J. H. Oort's theory of galactic rotation by the stellar radial velocities measured by Plaskett o 0 and Pearce: " . . . out of 250 stars only 4 were between 193 and 343 0 galactic longitude [=£1: 225

The general background of this monograph and the aim of it is described in detail in Chapter I. As stated in 1.7 it is written according to the principle that "when rigour appears to conflict with simplicity, simplicity is given preference", which means that it is intended for a rather broad public. Not only graduate students but also advanced undergraduates should be able to understand at least most of it. This monograph is the result of many years of inspiring discussions with a number of colleagues, for which I want to thank them very much. Especially I should mention the groups in Stockholm and La Jolla: in Stockholm, Dr Carl-Gunne Flilthammar and many of his collaborators, including Drs Lars Block, Per Carlqvist, Lennart lindberg, Michael Raadu, Staffan Torven, Miroslav Babic, and Itlgvar Axniis, and further, Drs Bo Lehnert and Bjorn Bonnevier, all at the Royal Institute of Technology. Of other col leagues in Sweden, I should mention Dr Bertel Laurent, Stockholm University, Dr Aina Elvius, The Stockholm Observatory, and Dr Bengt Hultqvist, Kiruna. In La Jolla my thanks go first of all to Dr Gustaf Arrhenius, who once invited me to La Jolla, which was the start of a most interesting collaboration; further, to Dr W.B.

The large-scale structure of the Universe and systems Clusters, and Groups of galaxies are topics like Superclusters, They fully justify the meeting on "Clusters of great interest. and Groups of Galaxies". The topics covered included the spatial distribution and the clustering of galaxies; the properties of Superclusters, Clusters and Groups of galaxies; radio and X-ray observations; the problem of unseen matter; theories concerning hierarchical clustering, pancakes, cluster and galaxy formation and evolution. The meeting was held at the International Center for Theoretical Physics in Trieste (Italy) from September 13 to September 16, 1983. It was attended by about 150 participants from 22 nations who presented 67 invited lectures (il) and contributed papers (cp), and 45 poster papers (pp). The Scientific Organizing Committee consisted of F. Bertola, P. Biermann, A. Cavaliere, N. Dallaporta, D. Gerba1, M. Hack, J . V . Peach, D. Sciama (Chairman), G. Setti, M. Tarenghi. We are particularly indebted to D. Sciama, A. Cavaliere and F. Bertola for their work of coordination. We were acting as the three members of the Local Organizing Committee. Moreover, we are pleased to thank the Chairmen of the Sessions (M. Hack, N. Da11aporta, G. Burbidge, B. Mills, M. Rees, P. Biermann, L.Z. Fang, L. Gouguenheim) for their valuable help.

Michael Friedjung Though known since antiquity, novae are still poorly under stood and present many problems. There has tended to be a lack of communication between theoreticians and observers and between different schools of thought, in spite of the advances of recent years in certain directions (observations of ordinary novae at minimum and of dwarf novae, theory of the causes of the explosion, etc ••• ). The meeting whose proceedings are contained in this volume was organized to stimulate a confron tation between the different ideas and results. The subject has changed a lot since 1963, when the previous international meeting was held. There were 61 participants at the conference from 17 countries, so very many groups ~oing research in the field of novae were represented. The reader will see that the subject has become more physical (we know for instance that the binary nature of novae is essential) but much work remains to be done. There is still a large gulf between theory and observation. May he find here many new ideas for future research! I would like to thank the French Centre National de la Recherche Scientifique for providing financial help. I must also thank the other members of the scientific committee (Profs and Drs Bath, Mustel, Payne-Gaposchkin, Sparks and Warner) and of the local committee (Audouze, Mrs Steinberg, Vauclair).

The progress of science during the past centuries has been in some measure energized by the development of new technologies. People are no more intelligent now than they were five centuries ago, or indeed five millenia ago. The differences are in the pool of past experience and the availability of means for manipulating the physical and mental environment. Until fairly recently, the development of new technologies in astronomy and geodesy has served primarily either to broaden the scope of phenomena that could be studied or to improve the precision with which one could examine already-studied phenomena. There seemed to be no likelihood that a situation could arise similar to that in particle physics, where the uncertainty principle indicates that the observation of the state of an object alters that state, affecting the observation. Indeed, we have not yet reached that point, but certain of the new techniques have introduced a degree of complication and inter dependence perhaps not previously encountered in the macro sciences. When observational capability is so fine that the data can be corrupted by the tidal motions of the instruments, for example, then there are a myriad of physical effects that must be considered in analyzing the data; the happy aspect of this is that the data can be used to study exactly these same effects. The complication does not, however, extend only to predictive computations against which the data are compared.

Proceedings of a Symposium organized within the XIXth URSI General Assembly held in Helsinki, Finland, July 31-August 8, 1978