Edmund Scientific sells superconducting ceramic discs for educational laboratory demonstrations. The kit includes a disk of YBa_2Cu_3O_7, holder, instructions and bibliography. Contact Edmund Scientific, 101 East Gloucester Pike, Barrington,New Jersey 08007; telephone (609) 573-6250.

Sargent-Welch Scientific sells a superconductivity demonstration kit, which includes experiments demonstrating the Meissner effect, zero-resistance and quantum mechanical effects, and the variables of T_c, J_c, and H_c. Contact Sargent-Welch Scientific Company, 7300 N Linden Ave., Skokie Illinois 67007; telephone (800) SARGENT.

Colorado Superconductor, Inc. sells several superconducting kits which demonstrate the Meissner effect, as well as measurement of T_c, H_c, and current density. Contact Colorado Superconductors Inc. at P.O. Box 8223, Fort Collins, Colorado 80526; telephone (303) 491-9106.

Futurescience, Inc. sells a variety of superconducting kits for classroom demonstration and student use. Kits fit nicely on your bookcase and hold the necessary items. One kit has a videotape with extensive safety content, simple cryogenic demonstrations, and examples of activities that can be performed with other kits. Contact Futurescience, P. O. Box 17179, Colorado Springs, CO, 80935, 303-797-2933, 719-634-0185, Fax 719-633-3438

CeraNova Corporation produces helical coils of YBCO. These coils are useful in laboratory superconductivity demonstrations, especially where high resistances above liquid nitrogen temperatures are needed. Contact CeraNova at 14 Menfi Way, Hopedale, MA 01747; phone or fax (508) 473-3200

Date posted 04/01/96 (ktb)