Norman Savage Boulton (1899–1984): civil engineer and groundwater hydrologist
Norman S. Boulton (Fig. 1) was a civil engineer who achieved international recognition for his work on groundwater hydraulics. He recognized that in unconfined aquifers water is released from storage by drainage under gravity from the pore-spaces in the cone of depression as it expands. This ‘delayed yield’ gave a characteristic S-shape to the log-log, time-drawdown graph of water levels in an observation well near a pumping well. Boulton developed a mathematical solution that reproduced the three segments of the curve. Most of his career was spent in academia mainly at the University of Sheffield where he was Professor of Civil Engineering between 1955 and 1964. His work embraced studies of structural engineering and soil mechanics as well as groundwater flow.