Discusses the atmospheric characteristics of the earth and their implications for the development of life on earth-like planets. Indicates that the chance of life developing on other planets is not as great as men might have thought. (CC)

Applications of wheels are shown to be an invaluable tool in teaching the processes and technology of science. (DF)

An experiment in which both Raman-Nath and Bragg diffraction of light by acoustic waves in water are observed in the sound frequency range from 5 to 45 MHz. The apparatus consists of a laser, light detector, rf power source, quartz transducer, and homemade water cell. (Author/DF)

Describes the operation principles, construction, and accessories of a land or survey gyrocompass. Indicates an agreement within O.1 degree in the direct comparison of the gyro-north with the astronomic north. (CC)

Presents the theoretical explanation of the observation that when a pen that is stuck in a hard rubber ball and dropped, the pen may bounce to several times the dropped height. Includes the procedure and models created to explain the observations. (DS)