Salomon de Caus was a French Huguenot engineer, once (falsely) credited with the development of the steam engine.
He was the elder brother of Isaac de Caus. Being a Huguenot, Caus spent his life moving across Europe.
He worked as an hydraulic engineer and architect under Louis XIII. Caus also designed gardens in England, that of Somerset Houseamong them; also, the Hortus Palatinus, or Garden of the Palatinate, in Heidelberg, Germany.
In 1615, he published a book showing a steam-driven pump similar to one developed by Giovanni Battista della Porta fourteen years earlier. Nevertheless, François Arago called him the inventor of the steam engine as a result.
In this same book, Les Raisons des forces mouvantes, Caus presents a well-known just-intonation scale, now known as the Ellis Duodene, after Alexander John Ellis who reinvented it. It is to Caus that the term work is owed in the sense that it is used in the field of mechanics.