This Proceedings is a collection of papers presented at the Third Annual Conference on Superconductivity and Applications organized by the New York State Institute on Superconductivity. This year the Conference was held at the Buffalo Hilton Hotel on September 19- 21, 1989, with previous meetings on September 28-29,1987, and April 18-20, 1988. As in previous years, this meeting was highly successful, with an attendance of over three hundred researchers participating in lively scientific exchanges and discussions. The high quality of the talks is evident in this Proceedings. The field of high...