19th century in science Carnot captured some of the ideas of thermodynamics in his discussion of the efficiency of an idealized engine. Sadi Carnot's work provided a basis for the formulation of the first law of thermodynamics—a restatement of the law of conservation of energy—which was stated around 1850 by William Thomson, later known as Lord Kelvin, and Rudolf Clausius. Lord Kelvin, who had extended the concept of absolute zero from gases to all substances in 1848, drew upon the engineering theory of Lazare Carnot, Sadi Carnot, and Émile Clapeyron–as well as the experimentation of James Prescott Joule on the interchangeability of mechanical, chemical,
19th-century turnpikes in Massachusetts Massachusetts began in 1796, when the first act of incorporation for a turnpike was passed. By 1850, most turnpike corporations had either been dissolved or had stopped collecting tolls. In all, 118 acts of incorporation were passed (ten of these were in the territory that later became the state of Maine). Typical toll rates were twenty-five cents for every coach with additional charges of four cents for every man and horse. The following 19th century turnpikes were chartered and built in Massachusetts: 19th-century turnpikes in Massachusetts In the late 18th century and early 19th century, turnpikes, as opposed to ordinary