The scientific expedition of H.M.S. Challenger in the 1870s marks the starting point of physical oceanography. This ship traveled the seas of the globe pursuing a dual objective to conduct an indepth study of animal life and to observe the physical properties of ocean waters. Volume 1 richly illustrated relates the expedition of the Challenger and addresses the problems of measuring the great depths. A theoretical approach to the immersion velocity of a probe is also proposed as well as a prese