|Title page to the 1859 A Manual of the Steam Engine and Other Prime Movers by Irish engineer William Rankine.|
In this work, Ranking introduces terms such as adiabatic and isothermal and stated one of the first definitions, after William Thomson (1854), of thermodynamics: 
“It is a matter of ordinary observation, that heat, by expanding bodies, is a source of mechanical energy; and conversely, that mechanical energy, being expended either in compressing bodies, or in friction, is a source of heat. The reduction of the laws according to which such phenomena take place, to a physical theory, or connected system of principles, constitutes what is called the science of thermodynamics.”
Rankine also gave the following definition of the second law: 
“If the absolute temperature of any uniformly hot substance be divided into any number of equal parts, the effects of those parts in causing work to be performed are equal.”
The first chapter on the subject of "thermodynamics", according to Scottish physicist James Maxwell, is found in Rankine’s Manual, titled “Principles of Thermodynamics”. 
1. Cengel, Yunus A. and Boles, Michael A. (2002). Thermodynamics: an Engineering Approach (pg. 2). New York: McGraw-Hill.
2. (a) Rankine, William. (1859). Manual of the Steam Engine and Other Prime Movers (adiabatic, pgs. 302) (chapter III: “Principles of Thermodynamics”, pgs. 299-478). London: Charles Griffin and Co.
(b) 1888, 12th Edition.
3. Ewing, James A. (1902). The Steam-Engine and other Heat-Engines (Section 73: Rankine’s statement of the Second Law, pgs. 89-90). University Press.
4. (a) Tait, Peter G. (1868). Sketch of Thermodynamics. Kessinger Publisher (reprint).
(b) Maxwell, James C. (1878). “Tait’s ‘Thermodynamics’ (I)”, (pgs. 257-59). Nature, Jan. 31.
(c) Maxwell, James C. (1878). “Tait’s ‘Thermodynamics’ (II)”, (pgs. 278-81). Nature, Feb. 07.
● Manual of the Steam Engine and Other Prime Movers – Encyclopedia Britannica.