J DAVID COOPER graduated in Physics from Imperial College, London. He spent 23 years as a soil physicist with the UK Institute of Hydrology, later the Centre for Ecology & Hydrology (CEH), followed by 12 years as Head of the Hydrological Instruments Group at CEH. His work has focussed mainly on field measurement of soil water and solute fluxes and of soil hydraulic properties in a wide variety of lithologies and areas of the world, including at several sites in southern England, northern France, Kenya, Niger, Mauritius, India and China. He has contributed to advances in measurement of soil water content by neutron, capacitance and time domain reflectometry techniques, hydraulic properties measurement methods in situ in the field and soil water potential measurement using mercury manometer and pressure transducer tensiometers over extended periods at both shallow and deep depths, down to at least 60 m. He has six children and, at the time of writing, nine grandchildren.