Describes a micromanipulator that is inexpensive, simple to build, rugged, and capable of several modes of operation beyond those of other types. It can, for example, be used with its controls quite remote from the tool holder and microscope or be controlled by computer. (JN)

A homemade device for testing particle scattering is described. Also described are experiments in zero gravity conducted in free fall in the cargo space of an airplane belonging to the National Aeronautics and Space Administration. (JN)

The preparation and performance of a graphite (silver/copper sulfide) electrode is described. This rod, extracted from a used dry cell, is an acceptable substitute for ion-selective electrodes after it has been cleaned by abrasion followed by an overnight treatment with hydrochloric acid. (JN)

Short articles describe the use of a lever to transfer energy between pucks on a frictionless surface, a demonstration of the principle of conservation of linear momentum, the construction of an inexpensive joulemeter, the design and construction of a simple logic demonstration board using integrated circuits, mounting of Geiger-counters to…