Salomon de Caus (1576 in Dieppe – 1626) was a French engineer and once (falsely) credited with the development of the steam engine.
Salomon was the elder brother of Isaac de Caus. Being a Huguenot, he spent his life moving across Europe.
De Caus worked as an hydraulic engineer and architect under Louis XIII. He also designed gardens in England, the one of Somerset House among them; also, the Hortus Palatinus, the 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, de Caus presents[1] a well-known just-intonation scale, now known as the Ellis Duodene, after Alexander John Ellis who reinvented it.