Vapors for heat engines, including considerations relating to the use of fluids other than steam for power generation; a study of desirable vacuum limits in simple condensing engines: methods for computing efficiencies of vapor cycles with limited expansion and superheat; a volume-temperature equation for dry steam, and new temperature-entropy diagrams for various engineering vapors
A 1912 engineering monograph by William D. Ennis, published in New York by D. Van Nostrand, analyzing vapors other than steam as working fluids for heat engines, written for mechanical engineers and power-plant designers. The plates are line thermodynamic charts—pressure-volume and temperature-entropy axes with lettered points, dashed construction lines, saturation curves and inline temperature labels—usable as diagram vocabulary, technical line motifs, and italic-letter annotation styles.
