Discusses the use of a modified electron spin resonance apparatus to demonstrate some features of the expression for the transition probability per second between two energy levels. Applications to the third year laboratory program are suggested. (CC)

Directions are given for the construction of mazes suitable for use in the classroom. The animal maze may be used to investigate small animal behavior, and the finger maze provides students with the opportunity to experience similar frustrations to those encountered by animals in the network of passages. (JR)

Discusses the principles, construction, and operation of an apparatus which serves to demonstrate the non-colinearity of the angular velocity and momentum vectors as well as the inertial tensors. Applications of the apparatus to teaching of advanced undergraduate mechanics courses are recommended. (CC)

Discusses the construction of a diffractometer table and four microwave models which are built of styrofoam balls with implanted metallic reflecting spheres and designed to simulate the structures of carbon (graphite structure), sodium chloride, tin oxide, and palladium oxide. Included are samples of Bragg patterns and computer-analysis results.…

In the transition from the traditional science teaching approach to an activity centered curriculum, useful pieces of scientific equipment are often no longer needed and stored. Suggests ways in which the resourceful teacher can use this equipment to supplement the new curriculum with additional student activities. (JR)

Presents ideas from readers on techniques and equipment that might be useful in teaching secondary school science. Suggests how to construct cheap wall charts, modify a vacuum cleaner into a blower, construct a stereo microscope lamp holder, and outlines simple physics laboratory experiments. (JR)

Discusses the theories, construction, operation, types, and advantages of fuel cells developed by the American space programs. Indicates that the cell is an ideal small-scale power source characterized by its compactness, high efficiency, reliability, and freedom from polluting fumes. (CC)

Describes the construction and operational procedures of a spark-timing apparatus which is designed to record the back and forth motion of one or two carts on linear air tracks. Applications to measurements of velocity, acceleration, simple harmonic motion, and collision problems are illustrated. (CC)

Describes an experiment suitable for high school physics classes in which students determine the wavelength of electromagnetic radiation of u.h.f. television transmissions. Elaborate equipment is not required, and details are given for the construction of a dipole. (JR)

Describes how to construct a bulletin board with a light that flashes when the correct answer is matched with a question. (JR)