Other in Taylor's immediate circle of followers were Carl Barth (1860-1939), Taylor's mathematician and developer of special-purpose slide rules for setting "feeds and speeds" for metal cutting; Morris Cook (1872-1960), who applied Taylor's ideas both in industry and as director of Public Works in Philadelphia; and Horace Hathaway (1874-1944), who personally directed the installation of scientific management at Tabor Manufacturing Company and wrote extensively on scientific management in the technical literature.