James B. Francis
(1815 - 1892) played a vital role as an engineer
in the development of locks and canals
in Lowell, Massachusetts
. His two most prominent achievements were: the development of Uriah A. Boyden's turbine for harnessing water power and the research in hydraulics with use of the weir (a device that helps measure flow rate of rivers). His turbine was influential because it channeled water through the center, thereby making it much more efficient; his research was influential because it developed a way to easily tell how much water power each company in Lowell used.
Francis was very skeptical of theoretical science, and constantly relied on meticulous testing to achieve results.