Describes: the chemical history of a pencil; a simple solar camera for measuring the sun's diameter; the experimental comparison of the thermal stability of metal carbonates; and the introduction of the concept of weight as a force to young children. A computer program listing on color mixing is also provided. (JN)

Discusses various types of transducers and explains the use of a photoresistor in sensing light. Describes various hardware and software combinations which can be used with photoresistors in science laboratory experiments. Presents general applications of this instrument in light-meter, solarimeter, and colorimeter experiments. (TW)