In 1615, Caus, in his The Reason for Moving Forces, the title page shown adjacent, with Archimedes and Hero at bottom, shown contriving different things, gives a number of hydraulically-powered devices, such as a water-powered Neptune automaton, possibly similar to that seen and ruminated on by Rene Descartes.
Quotes | On
The following are quotes on Caus:
- “Both Cardan and Porta were concerned with the phenomena of steam, but though they made some progress their results were seriously qualified by misconceptions of the nature of steam, which they still identified with air. Cardan in one obscure passage (1550) points out that a vacuum may be created by the condensation of steam; this suggestion, cogent as it would have been if clearly conceived, can hardly have had the significance that we might naturally be inclined to attribute to it. Porta's work on steam was rather more deliberate, and some of his experimental apparatus was highly suggestive. The attempt to measure the volume of steam by the amount of water displaced by steam pressure led him close to a positive distinction between steam and air, but he drew no decisive conclusions him-self. A late contemporary, Salomon de Caus, with essentially similar apparatus, took this decisive step. He declared that steam is evaporated water, and that upon cooling the vapor returns to its original condition. A similar experiment with mercury showed the same phenomena of evaporation and subsequent return to the liquid condition. De Caus was thus able to set down (1615) a series of propositions that represented a great advance upon all previous achievements in the field of gases and their phenomena. Air and steam were thus specifically distinguished and the practical conclusion was drawn that there were potentialities in steam pressure of much greater magnitude than were to be found in air pressure.”
- — Abbott Usher (1929), A History of Mechanical Inventions (pg. 342) 
- Caus, Salomon. (1615). The Reasons for Moving Forces (Les Raisons des forces mouvantes) (Neptune, pg. 35). Publisher.
- Salomon de Caus – Hmolpedia 2020.