Spurred by National Aeronautics and Space Administration (NASA) technological advances, a budding industry is manufacturing equipment and providing services toward better management of earth's resources. Topics discussed include image processing, multispectral photography, ground use sensor, and weather data receiver. (Author/JN)

Describes experiments on properties of leather performed by a science teacher, assisted by senior science students. Concludes that the finish layer contributes a major part of the resistance to air passage, reducing permeability of leather. Flexing increases permeability and may, in its action, discriminate between finishes. (Author/JN)

Describes: (1) an apparatus which provides a simple method for measuring Stefan's constant; (2) a simple phase shifting circuit; (3) a radioactive decay computer program (for ZX81); and (4) phase difference between transformer voltages. (Author/JN)

Describes a simple, student-oriented method of determining seiches and compares actual to theoretical results. Includes information about equipment needed, data gathering, and analysis of the data. (Author/DS)

Discusses and lists, in table form, the specifications and characteristics of 28 low-cost digital multimeters, including jacks, number of V ranges, max V, cost, approximate percent accuracy, current scales, display, battery life, volume, and manufacturers. Quality of construction, ease of repair, and similar characteristics not reported. (SK)

Describes an inexpensive, easy-to-construct manometric device that is a substitute for an expensive commercial transducer that is sensitive to slight pressure fluctuations. An activity for demonstrating the importance of CO-2 as a humoral regulator of respiration is described. (Author/SA)

Basic marine aquaria equipment, techniques for maintenance, specimens and food for the marine organisms are discussed. Several sources of specimens are included. (SA)

Presents background information on and instructions for constructing a Hero's water fountain. Includes photographs of the apparatus from old textbooks and one in the collection of the National Museum of History and Technology at the Smithsonian Institution. (SK)

Describes some scientific concepts illustrated by and sources of Sterling engines. Includes an elementary version of their theory. (JN)

Outlined are procedures for using satellites including the mechanics (plotting satellite positions and obtaining readable signals) and secondary and college activities (using Oscar 8 data telemetry, obtaining weather pictures, using a computer). (DC)

Discusses how TOPS devices can be improved. New chemistry-physics devices are offered in hopes of encouraging teachers to invent other small devices for projection on a TOPS projector-adaptor. (HM)

Gives instructions for simple meteorological instruments that students can make and then use to monitor temperature, humidity, dew point, rainfall, and wind speed. (SJL)

Describes a simple seismograph which can be built quite easily and is sufficiently sensitive to record earthquake waves at home. (HM)

Describes an advanced undergraduate physics experiment which permits the measurement of ultrasound velocity and absorption in liquid systems. A description of the tasks the student is expected to perform is also included. (HM)

Describes a demonstration in which the local inertial frame of reference can be obtained in the laboratory by allowing a cage to fall freely without rotation under the influence of gravity. (HM)