Describes an apparatus designed for demonstrating electron and ion-optical principles. The apparatus consists of (1) a high-vacuum system and (2) electron-optical components. The teaching techniques used and the experiments conducted are reported. The apparatus won second prize in Demonstration Lecture Apparatus in the A.A.P.T. Apparatus…

Describes an apparatus designed to study the properties of charged particles suspended in an electric field. The apparatus consists of a suspension chamber, an optical system and power supplies and controls. Experiments conducted include determination of particle size, charge-to-mass ratio and particle collisions and exchange. (LC)

Describes an apparatus designed for observing the motion of delicate mechanical systems. The apparatus consists of a light-spot follower attachment connected to a servo-recorder. The oscillations of a triple-torsion pendulum and of a Cavendish balance have been studied. (LC)

Describes an apparatus designed to demonstrate vortical flow of a fluid. The apparatus consists of a transparent acrylic cylinder, with a drain hole, and mounted so that it can be rotated about its axis at speeds up to 1000 rpm. Experimental observations with water as the fluid under study are reported. (LC)

Describes a novel and simple method of measuring the refractive index of transparent plates using a Michelson interferometer. Since it is necessary to use a computer program when determining the refractive index, undergraduates could be given the opportunity of writing their own programs. (Author/JN)

A remote, programed oven temperature controller unit was built for about $425.00. Specifications, circuit diagrams, design details, and operations are discussed. Detailed information including complete schematics, parts list, and detailed theory of operation may be obtained by contacting the author. (Author/SK)

Examines the controversy surrounding the validity and interpretation of electron microscope images. (DS)

Presents seven notes on new equipment, techniques, or materials of interest to teachers of physics. A circuit of a low-cost computer terminal to audiovisual device interface, and a demonstration of the buoyancy of air are among notes presented. (HM)

Describes methods for converting a large refrigerator or freezer into a microbiological incubator, in which a heater and temperature regulator are installed. (CS)

Describes a way to construct from aluminum foil and a tin can a detector of ionizing radiation in the environment. (Author/SA)