Charles Metcalf Allen
Charles Metcalf Allen ( 1871 in Walpole , Massachusetts – 1950 in Holden , Massachusetts ) was a hydraulic engineer known particularly for his inventions and development of the Allen Salt-Velocity Method for measuring water discharge in situations where other methods or instruments could not be easily used . 
<triplet> Charles Metcalf Allen <subj> hydraulic engineer <obj> field of work