Local heat-transfer coefficients in forced convection, downflow boiling, and nonboiling were measured by use of an electrically heated type-304 stainless steel tube (0.7194 in. i.d. x 0.7502 in. o.d. x 68.0 in. long). Average forcedconvection heat-transfer coefficients in turbulent onephase flow and local total pressure gradients in two-phase flow were also determined. Data were obtained for the boiling of distilled water with mass fluxes of 51 to 165 lb/sec sq ft, heat fluxes from 13.8 x 10/sup 3/ to 49.8 x 10/sup 3/ BTU/hr sq ft, pressures at 15.8 to 30.9 psia, and qualities up to 14%. The boiling heat transfer data were compared with the correlations proposed by Mumm, Dengler, Rohsenow, and Grossman and Schrock. No attempt was made to formulate a new correlation because of the limited range of conditions investigated. The nonboiling heat transfer data were compared to the Dittus-Poelter and SiederTate correlations. The local total pressure gradients in two-phase flow were correlated by the Martinelli parameter, X/sub tt/, for turbulent two-phase flow. (auth)