On 15 September 2004, Paul Melchior passed away. He was 78 years old. Melchior contributed immensely to the development of geophysics and geodesy, in particular in the field of Earth tides. During his long and fruitful scientific career, Melchior had been director of the International Center for Earth Tides (1958-1995), president of the Commission of Earth Rotation (1958-1995) of the International Astronomical Union (1967-1970), and president of the International Council for Science's Committee on Data for Science and Technology (CODATA) (1974-1978). He began measuring Earth tides in 1957 with the Verbaandert-Melchior Quartz tiltmeters. In 1973, his skillful and accurate interpretation of Earth tide gravity observations led the U.S. Air Force to entrust his team to carry out Trans World Tidal Gravity Profiles. A total of 127 stations were observed worldwide for tidal stations at least six months. This exceptional data set was used to assess the precision of the oceanic tidal models derived from TOPEX-Poseidon (the TOPography EXperiment for ocean circulation Joint U.S.-French orbital mission), launched in 1992 to track changes in sea- level height with radar altimeters ago. Always seeking more precise observations in gravimetry, Melchior succeeded in raising funds to install the first superconducting gravimeter in Europe, in Brussels in 1981.