# Dictionary of National Biography, 1885-1900/De Caus, Salomon

Died 1626 according to later editions.
​DE CAUS, CAULS, or CAUX, SALOMON (1576–1630), engineer and architect, a native of Normandy, probably of the town of Caux, was born in 1576. He applied himself at an early age to the study of the mathematical sciences, his favourite writers being Archimedes, Euclid, and Vitruvius. After a visit to Italy he came to England as mathematical tutor to Henry, prince of Wales, and in 1612 published a work entitled ‘La Perspective avec la raison des ombres et Miroirs;’ in the dedication of this work to that prince, dated at Richmond, 1 Oct. 1611, he states that he has been two or three years in the service of his royal highness. He seems also to have been employed as drawing-master to the Princess Elizabeth. After the death of the young Prince of Wales De Caus was, in 1613, employed by the elector palatine, Frederick V, then recently married to the Princess Elizabeth, to lay out the gardens at the castle of Heidelberg. This work occupied De Caus some years, and was not completed when the assumption by the elector palatine of the throne of Bohemia and the outbreak of the thirty years' war put an end to further operations. De Caus, however, published in 1620 his complete designs in a work entitled ‘Hortus Palatinus a Friderico Rege Boemiæ Electore Palatino Heidelbergæ exstructus.’ De Caus is also stated to have been the architect of the ‘Englische Bau’ and other portions of the castle of Heidelberg, erected at that time by Frederick V, but this seems doubtful. While at Heidelberg De Caus published in 1615 ‘Institution Harmonique, divisée en deux parties; en la première sont monstrées les proportions des Intervalles harmoniques et en la deuxiesme les compositions d'icelles.’ In the dedication of this work to Anne, queen of Great Britain, dated 15 Sept. 1614, he says that his experiments in the mechanical powers of water were commenced while in the service of the late Prince of Wales. In the same year, 1615, he published his most important work, ‘Les Raisons des Forces Mouvantes avec diverses Machines tant utilles que plaisantes Ausquelles sont adjoints plusieurs desseings de grotes et fontaines.’ This work is divided into three parts, all copiously illustrated: I. ‘Les Théorèmes et Problèmes des Forces Mouvantes;’ II. ‘Des Grotes et Fontaines pour l'ornement des Maisons de Plaisance et Jardins;’ III. ‘De la Fabrique des Orgues.’ The second part contains, as he himself says in the dedication to Princess Elizabeth, many designs formerly made at Richmond for the adornment of the palace, or the entertainment of his master, the Prince of Wales. In the first part occur his enunciations of the theorems of the expansion and condensation of steam, and of the elevation of water by the application of heat, which have gained for him in some quarters the honour of being the first inventor of the steam engine, though De Caus seems only to have utilised them for fountains and other waterworks and claims no originality. It is almost certain that Edward Somerset, second marquis of Worcester [q. v.], to whom this honour has also been ascribed, and later engineers, knew and developed the principles enunciated by De Caus. There is an apocryphal story that De Caus lost his reason from chagrin at being unable to convince Cardinal Richelieu of the importance of his discoveries, and while at Bicêtre in confinement was accidentally discovered by the Marquis of Worcester, who extracted from him the secret of his inventions, and then brought them out as his own. De Caus's work was translated into German under his own supervision. In 1623 he quitted the service of the elector palatine and returned to France; there in 1624 he published a work on sun-dials, ‘La Pratique et Demonstration des Horloges Solaires,’ which he dedicated to Cardinal Richelieu; in the preface to this work he states that he was preparing a translation of Vitruvius, but this does not appear to have been completed. He seems to have died in Paris on 6 June 1626. While in England in 1611–13 De Caus built a gallery at Richmond Palace, subsequently completed as a picture gallery by Charles I; and he erected the south front of Wilton House, which was destroyed by fire in 1647, and rebuilt from the designs of Inigo Jones. He was largely employed on the gardens at Greenwich Palace and Somerset House, and numerous payments are recorded to the ‘Frenche gardiner’ for these services (Brit. Mus. Lansd. MS. 164), and for those at Richmond (Archæologia, xv. 17). His contributions to musical science are also worthy of note. He left a son, or nephew, Isaac De Caus, a native of Dieppe, as he calls himself, who was employed in the external decorations at Gorhambury and Campden House, Kensington, and laid out the gardens at Wilton House, of which he published a series of etchings. In 1644 he published a work entitled ‘Nouvelle Invention de lever l'eau plus hault ​que sa source, avec quelques Machines mouvantes par le moyen de l'eau et un discours de la conduite d'icelle;’ this work seems to be a mere restatement of the theorems of Salomon De Caus, but was thought worthy of being translated into English by John Leak in 1659. In this translation he is alluded to as ‘a late famous engenier.’ There is a portrait of Salomon De Caus in the castle museum at Heidelberg, which was engraved in the ‘Magasin Pittoresque’ (xviii. 193).
L. C.