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)

A description is given in which a computer program can be used to illustrate principles of statistical mechanics. The concepts of ensembles, statistical averages, and responses are classified particularly with respect to the role of statistical fluctuations. (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)

Two problems are investigated: (1) the fact that statistics from pretests sometimes vary widely from those for the actual test; (2) whether or not a correction factor should be applied for guessing. (DF)

The potential of the computer usage in instruction is discussed. A project was initiated to identify areas where the computer might yield significant advances in teaching. (DF)