Milestones

DIED. William S. Halstead, 84, prolific inventor whose more than 80 patents include the technology for adding stereo sound in motion pictures; of pneumonia; in Los Angeles. Halstead, born in Mount Kisco, N.Y., in 1950 developed a system that allowed FM stations to use sidebands of their main frequencies for stereo transmission. After World War II, Halstead helped create the first commercial TV network in Japan.