Danny Dunn on the Ocean Floor by
Call Number: Not available--request via Interlibrary Loan
Another accident in Professor Bulfinch's laboratory, instigated by Danny, results in the creation of a transparent, resilient material. The material proves useful in creating a bathysphere, and Professor Bulfinch, along with his friend Dr. Grimes, Danny, Joe, and Irene, descends into the Pacific Ocean on an experimental voyage. Unfortunately, the bathysphere's pilot is rendered unconscious, and the bathysphere becomes trapped in a cave.