The year 1973 marked the first time that Atlanta, one of the cultural centers of the South, has hosted the Cryogenic Engineering Conference since its beginning in 1954. The Cryogenic Engineering Conference gratefully acknowledges the hospital ity of the Georgia Institute of Technology and the assistance of W. T. Ziegler and his staff in making the visit to Atlanta a pleasant and memorable one. Several significant changes were initiated at the 1973 Cryogenic Engineering Conference. These included a Conference theme on the subject of "Energy and the Environment," a new Conference format, and the beginning of a new Conference frequency of biennial meetings. While retaining the traditional topics of previous meetings, the 1973 Cryogenic Engineering Conference focused on the role of cryo genic engineering in the generation, distribution, and conversion of energy, and the related environmental effects. In these areas, much of the current interest stems from the environmental effects of LNG and liquid hydrogen as compared with other competing energy forms. These rapidly expanding areas may provide the impetus to cryogenic engineering in the 1970's that the space program provided in the 1960's. The Conference format was altered by the use of numerous invited papers highlighting the theme. These presentations were concentrated in plenary sessions initiating each day's activities, and in seminars designed to summarize the various aspects of the theme."

The Second International Cryogenic Materials Conference (ICMC) was held in Boulder, Colorado, in conjunction with the 1977 Cryogenic Engineering Con ference (CEC). Special thanks must be given to the University of Colorado for their skillful hosting of these two conferences. Collaboration between the two con ferences has been mutually beneficial, providing the materials special ist with insight into new applications and design concepts and the cryogenic engineer with exposure to modern materials accomplishments and potentials. The Proceedings of the 1977 Cryogenic Engineering Conference are published in Volume 23 of Advances in Cryogenic Engineering. Both conferences will be held again simul taneously in Madison, Wisconsin, in August 1979. The success and growth of the two International Cryogenic Materials Con ferences have led to the formation of an ICMC Board of Directors. The board members will serve a four-year term and include: Chairman, R. P. Reed (U.S.), R. W. Boom (U.S.), A. F. Clark (U.S.), G. Hartwig (W. Germany), J. W. Morris (U.S.), M. Suenaga (U.S.), K. Tachikawa (Japan), J. Tanaka (Japan), and K. A. Yushchenko (USSR)."

The First International Cryogenic Materials Conference (ICMC) provided a new forum for the presentation of low-temperature materials research. The confer ence, held in conjunction with the 1975 Cryogenic Engineering Conference, provided materials research personnel with excellent exposure to current develop ments in the cryogenics field and beneficial interactions with designers of cryogenic systems. Because of the large response to a late call for papers, the enthusiasm and encouragement at the meeting, and the wide spectrum and high quality of papers, the Second International Cryogenic Materials Conference is being planned along with the 1977 Cryogenic Engineering Conference for Boulder, Colorado, in the summer of 1977. The success of the First International Cryogenic Materials Conference was certainly in large measure due to the excellent hospitality of our Canadian hosts, the Royal Military College of Canada and Queen's University in Kingston, Ontario. In particular, the efforts of A. C. Leonard and his staff ensured an excellent conference and a pleasant and memorable visit to Canada. The Cryogenic Engineering Conference Board was both generous and skillful in helping to initiate this new conference and their guidance and acceptance is gratefully acknowledged. The Cryogenic Engineering Conference program chairman, M. J. Hiza, greatly facilitated the interaction for the two conferences and provided valuable assistance in generat ing a workable program. The proceedings of the 1975 Cryogenic Engineering Conference are published as Volume 21 of the Advances in Cryogenic Engineering and include many papers indicating innovative use of new cryogenic materials properties data."

With the 1975 Cryogenic Engineering Conference this se ries enters the third decade of presenting the latest advances in the field of cryogenic engineering. The 1975 Cryogenic Engineering Conference also marked the first time the meeting had been held outside the territorial limits of the United States. Based on the enthusiastic response of the attendees and the exemplary hospitality of the Canadian hosts, it certainly will not be the last meeting to convene beyond the confines of the fifty states. The Cryogenic Engineering Conference Board is extremely grateful to The Royal Military College of Canada and Queen's University for the invitation to hold this meeting in Kingston, Ontario, Canada. The assistance of A. C. Leonard and his staff added immeasurably in making this visit to Canada both a pie asant and a memorable one. The 1975 Cryogenic Engineering Conference was the first meeting of this group on the new biennial conference schedule. Since the last conference in 1973, the Western Hemisphere has experienced the impact of various energy shortages. Thus, it was appropriate that the theme "Cryogenics Applied to Natural Resource Management" for this Conference was not only timely but also an opportunity for the scientific community engaged in cryogenic activities to review the role of cryogenics in meeting these new challenges and problems facing the energy-deficient nations of the world. The Cryogenic Engineering Conference was also pleased to have the Interna tional Cryogenic Materials Conference join them in this meeting."

In late 1877, Louis Cailletete in France and Raoul Pictet in Switzerland independently succeeded in liquefying oxygen, thereby proving a hypothesis set forth by Antoine Lavoisier nearly 100 years earlier. The theme of the 1977 Cryogenic Engineering Conference "Cryogenics: A Century of Progress-A Chal lenge for the Future" properly commemorated this accomplishment by reviewing some of the noteworthy advances since that time and outlining many advances still to come. Both Volumes 23 and 24 of this series provide a good account of the many contributions that were presented at this conference. The 1977 Cryogenic Engineering Conference was appropriately again held in Boulder, Colorado where the first Cryogenic Engineering Conference was initiated 23 years ago by the late Russell B. Scott, then Chief of the Cryogenic Engineering Laboratory of the National Bureau of Standards. The Cryogenic Engineering Conference Board is extremely grateful to members of the National Bureau of Standards and the University of Colorado for serving as hosts for this meeting of cryogenic specialists from all over the world. The Cryogenic Engineering Conference is again pleased to have had the International Cryogenic Materials Conference co-host this biennial meeting for the second time in succession. This joint effort again has permitted an in-depth coverage of research on technical materials in areas currently receiving primary attention by the cryogenic engineering community. The Proceedings of the Inter national Cryogenic Materials Conference will be published as Volume 24 of the Advances in Cryogenic Engineering."