An account of Van't Hoff's change from theoretical chemistry to petrology provides data on the European intellectual climate of the early 1900's and shows how his work laid the foundation for experimental petrology of hard rocks." (AL)

Details of the landscape of the planet Venus as revealed by the Magellan spacecraft are discussed and illustrated. Advances beyond previous space probes are demonstrated. Details of the program are described. Additional work from this project is proposed. (CW)

Describes progress made in recent decades in predicting the track and landfall of hurricanes. Examines the problems of detecting, tracking, and describing tropical cyclones, and the difficulties which continue to complicate the matter of warning and evacuating coastal residents. (JR)

Discusses a model for explaining the spread of human population explosion on North American continent since its discovery 12,000 years ago. The model may help to map the spread of Homo sapiens throughout the New World by using the extinction chronology of the Pleistocene megafauna. (Author/PS)

Comments on the positive values of international congresses and applauds the organization of the International Geological Congress in Montreal. (AL)

Describes efforts by government and professional associations to actively encourage the recruitment of minority group students and employees for extended training in the earch sciences. (AL)

Discussed are past work and recent advances in the use of electron microscopes for viewing structures immersed in gas and liquid. Improved environmental chambers make it possible to examine wet specimens easily. (Author/RH)

Describes atmospheric data monitoring as part of total airpollution control effort. Summarizes types of gaseous, liquid and solid pollutants and their sources; contrast between urban and rural environmental air quality; instrumentation to identify pollutants; and anticipated new non-wet chemical physical and physiochemical techniques tor cetection…