Author(s) Caus, Salomon de
Title La perspective, avec la raison des ombres et miroirs...
Imprint London, R. Barker, 1611
Localisation Paris, Ensba, Gonse 537
Subject Perspective
Transcribed version of the text


     Salomon de Caus was born in Dieppe in 1576 to a Protestant family. A part from a trip to Italy at the age of about twenty, nothing is known about the training or experiences which led to his being employed as an architect and engineer, specialising in hydraulics, in several European courts. His first office was at the court of Brussels, where, on the 21st January 1605, he was named as Engineer of the Archduke Albert and the Archduchess Isabella. In 1610 he arrived at the court of Prince Henry of Wales, where he worked until the prince’s death in 1612. While there, he taught perspective to the prince (the son of the future James I) and it is probable that he drew from this experience the basis of his first book La perspective, published in 1611 and again in 1612. Caus is sometimes credited with the design of the gardens at Greenwich and Somerset House, for James I (1566-1625). He was certainly employed, between 1612 and 1619, by Frederick V, Elector Palatine (1596-1632), for whom he designed and oversaw the creation of the garden of Heidelberg castle. In 1614 was appointed Engineer of the Buildings and Gardens of the Prince Elector, but was obliged to relinquish this post in 1620 when Frederick V was deprived of his titles by imperial decree and forced into exile at Sedan. Salomon de Caus had just time to publish his Hortus Palatinus before settling in France that same year. In spite of the protection of Richelieu and the proclamation of the Edict of Nantes (1598), it seems that Louis XIII’s court did not offer him the work opportunities he was used to. He did receive, on the 30th of March 1621, the title of King's Architect and Engineer and, according to one document, his duties included improving the sanitation of the streets of Paris, notably by removing accumulated waste and transporting water from the Seine. However, as far as we know, no record exists of his having actually carried out any works. Very little is known about his life after 1624, date of the publication of his last book, a treatise on gnomonics. Salomon de Caus died in Paris on the 28th of February 1626 and was buried in a Protestant cemetery.
La perspective was first published in London in 1611 by the royal printer Robert Barker, who also published that same year the famous “King James Bible”. There successively followed Les Raisons des forces mouvantes (Frankfurt, 1615), one of the first treatises on mechanics applied essentially to hydraulics; Institution harmonique (Frankfurt, 1615); Hortus Palatinus (Frankfurt, 1620) and La Pratique et la démonstration des horloges solaires (Paris, 1624). These publications, which cover perspective, hydraulics, architecture, gnomonics and musical theory, reveal Salomon de Caus as having common interests with numerous engineers and architects of his time: Simon Stevin from Bruges (1548-1620), Albert Girard (1595-1632) and Girard Desargues (1591-1661), to cite but a few. It is noteworthy that Salomon de Caus planned to provide the public with a translation of all or a part of the Vitruvius' Architecture and that he was interested in other problems of practical geometry, as proves the existence of a 37 page manuscript, currently conserved at the library at Valenciennes (ms. 339 (327)), which he dedicated to the king. The first part of this manuscript deals with the use of an instrument for sighting and measuring angles in surveying and topography which he called a “goniometer” (gonomètre): a proportional compass endowed with a trigonometrical scale. This is followed by a French translation of the first book of Vitruvius' Architecture, divided into eight chapters and illustrated by various views of a town house.
The treatise on perspective contains four parts and is illustrated by numerous diagrams and several full page engravings. The first section is concerned with preliminary generalities; it contains a plate of elementary geometric figures, eleven illustrated definitions of figures and ten theorems, equally illustrated by diagrams and one full page engraving. The second and longest part (31 chapters), enters into the heart of the matter, dealing successively with the following subjects: the rendering in perspective of progressively complex solid and void forms (capital, fountain, etc.); trompe-l’œil (the prolongation of a real garden by a painted one); anamorphosis (the principle, then two examples: the portrait and the full-length figure); finally, various cases of non frontal perspective rendering. The third section deals with the rendering in perspective of shadows cast by objects themselves rendered in perspective; it takes into account the nature (sunlight, torchlight) and position of the light source in relation to the other elements involved (the viewer's position, the picture's surface, the plane on which the shadow is cast). This third section (the second major section: it is entitled “Des Ombres, Livre deuxiesme”), includes a preamble containing a lengthy quotation from a poem by Partas on the subject of eclipses, followed by specifications concerning types of light and shadow (“Des diverses sortes de clairitez et des diverses sortes d’ombres ”). The fourth section (“Des Choses qui apparoissent aux Miroirs planes, & de la raison de telles apparitions ”) is concerned with the rendering in perspective of the reflections of objects in plane mirrors: it consists of six theorems. The treatise ends with a drawing, in perspective, of a hollow dodecahedron, whose pentagonal sides are replaced by five-point stars: a similar dodecahedron figures as a detail of the treatise's title page.
The originality of Salomon de Caus’ treatise on perspective stems from several factors which need to be underlined in order to fully understand the singularity and interest of the work. Firstly, it should be pointed out that this was the first treatise on perspective (in the new sense that this had acquired since Brunelleschi's innovatory experiments) to be printed in Great Britain – then a century behind France and northern Europe, and further still behind Italy, in matters of perspective theory. A second factor of originality is the use Salomon de Caus makes of the method he termed “by double projection” (par double projection): this method was not new in itself, but Salomon's almost exclusive use of it is truly exceptional – especially when compared with the scarce use of it made in both earlier and later perspective treatises. In point of fact, with the exception of the “chapitre vingt-septiesme” which presents “another way of foreshortening a square” (autre facon pour mettre un quarre en racourcissement), the “double projection” method is systematically used throughout the treatise. The “other way” presented in the “chapitre vingt-septiesme” suggests that Caus understood Alberti’s method, directly linked to the “double projection” method, but that he didn’t understand or else didn't appreciate the simplifying and expeditious consequences of the Albertian method. Though he misjudged Alberti's method – also known as the “third point” (tiers-points) or “distance-point” (point de distance) method –, which prevailed in his native country, the fact that he mentions it nevertheless offers insight into the nature and reasons of Salomon de Caus’ choices and his level of expertise. Another first in the history of perspective is the importance Caus accorded to subsidiary or connected aspects of this science, such as mirror reflections, anamorphosis, trompe-l’œil and shadows. Both the full title of Caus' treatise – “La perspective avec la raison des ombres et miroirs” – and its table of contents make immediately clear Salomon de Caus' intention to deal first with perspective rendering, then shadows and finally mirrors. As far as shadows are concerned – the subject of the second major part of the treatise –, Salomon de Caus, takes into account the work of his predecessors, in particular Albrecht Dürer, who had dealt with the subject in his Underweysung des Messung. It seems clear to Caus that the shadows cast by torchlight and central perspective itself share a single model. Thus, when a solid object is placed in the cone or pyramid of light emitted from a local light source (such as a torch), the form of the resulting shadow can be compared to the perspective image were the eye to take the place of the light source. This being, the shadow, once established by the light source, must be put into perspective from the draughtsman's point of view, similarly to the other objects observed. It is possible that Salomon de Caus' study of shadows was also influenced by Simon Stevin, who, in the 1605 Latin version of his treatise on perspective (printed at the same time in Low German), uses the term “skiagraphy” (shadow drawing) to designate perspective rendering: Jean Tuning and Albert Girard, in 1605 and 1634 respectively, translated the term into French as “ombragement” (shadowing). In any case, although Salomon de Caus mentions shadows cast by the sun (whose almost infinite distance, and thus almost parallel rays, create cylinders and prisms instead of cones and pyramids), all the detailed cases he exposes involve light sources situated close at hand and thus emitting a cone of light. To return to the point, if the section of shadows is not entirely original, that consecrated to the perspective rendering of mirror reflections is truly innovative. Here again, the draughtsman, having established the mirror image of the physical object in relation to the mirror's surface by way of symmetry, is encouraged to treat the image as a direct prolongation, beyond the mirror's surface, of the physical world. The connection between catoptrics and perspective is not however taken as far as it would be later in the century, with the development of mirror anamorphosis – rudimentary traces of which can incidentally be found in Vignola's work on mirrors (1507-1573). As for the two remaining subsidiary aspects – trompe l’œil and plane anamorphosis –, these do not form the objects of specific sections and are thus treated somewhat randomly. Not that this lessens the novelty of Caus' approach to these questions, as may be observed in chapter 25 of book I, wherein he exposes a method « for painting on a garden wall the image of garden, either similar or different to the one enclosed by the wall, such that when the wall be viewed from a window situated at a hundred feet from the wall and at height of thirty feet, the painted garden would seem as natural as the real garden and thus appear as a direct prolongation of the latter” (pour peindre contre la muraille d’un jardin un semblable jardin comme celuy qui est ou un autre que quand l’on sera esloigné de cent pieds de ladicte muraille en une fenestre de trente cinc pieds de haut, il semblera que ledict jardin peint soit naturel et contigent a celuy qui est naturel). Clearly, in this part of the treatise, Salomon de Caus draws directly on his experience in garden planning; anamorphosis, in the strict sense of the word (exclusively plane in Caus' case and referred to as “ an extraordinary way of foreshortening” (en racourcissement d’une façon extraordinaire), only appears in book I. Finally, Caus' Perspective is one of the first scientific treatises and, to our knowledge, the second on perspective, to make use of “volvelles” – detachable strips of paper added to full page drawings in theoretical and practical treatises, and serving an instrumental, explanatory and/or demonstrative purpose. These volvelles were either inserted by the bookbinder to be subsequently unfolded by the reader, or else furnished aside as supplementary pages, in which case it was up to the reader to cut them out and distribute them throughout the treatise. Their places in the Ensba edition probably correspond to the original composition.
A last remark on Salomon de Caus’ reflections on perspective: in 1624, he came back to the subject in La pratique et demonstration des horloges solaires... Proposition du premier livre d’Euclide. In the “Discours sur les proportions”, derived fromthe “35th Proposition” contained in the first book of Euclid's Elements, Caus demonstrates that “all volumes placed parallel to the plan that cuts the visual rays are themselves cut proportionally” (toutes les grandeurs qui sont paralleles au plan qui coupe les rays visuels sont coupées proportionnellement) – a fact which, according to him, constitutes “the principal theorem of perspective” (le principal Theoresme de ladite Perspective). He concludes by remarking on the consequences of this theorem: “one can then see that this proposition that Nature has inserted into the 35th proposition of the first book [of Euclid's Elements] concerns the proportionality of all foreshortening that perspective involves, as well as the proportionality of all the numbers, lines, surfaces and volumes – a reflection which leads to the comparison between, on one hand, geometry and, on the other, arithmetic and perspective” (L’on peut doncques voir que ceste Proposition que la Nature a inserée à ladite 35. Proposition du premier, est la semblable proportion des racourcissemens qui sont en la Perspective, & aussi de toutes les proportions des nombres, des lignes, des superficies, & des corps solides, réflexion qui introduit une Comparaison de la Geometrie avec l’Arithmetique & Perspective). Without going into these speculations in detail, it is interesting to note that this passage manifests the desire of this engineer nearing the end of his career to unify mathematics and the sciences related to it with a regulating principle, the theory of proportions, which, from perspective to gnomonics, underlies his work from first to last.
Salomon de Caus’ sources for La Perspective are various and their influence can be observed in several aspects of the book already evoked. Caus was obviously proficient in classical geometrical theory: he certainly read Euclid (probably in the 1570 edition prefaced by John Dee), he claimed to have read Vitruvius and Hero of Alexandria and he probably read Archimedes. Both the latter and Vitruve are mentioned in the poem by Jacques Le Maire which serves as an epigraphe for La Perspectiveand, in the case of Archimedes, this is an implicit reference to his work in statics and hydraulics. As for perspective, strictly speaking, it is probable that Caus learnt a fair amount during his trip to Italy, where he could have become acquainted with the theoretical and practical aspects either by word of mouths when mixing with scholars, or through the works of Serlio, Barbaro, Vignola, maybe even Alberti and almost certainly Piero della Francesca, whose treatise in manuscript form was frequently copied and – more or less exactly – quoted: extracts appear for example in the treatise by Daniele Barbaro, who also borrowed elements from Dürer. Salomon de Caus himself cites several authors, mostly to point out their mistakes, rectifiable by following his own method: Euclid in the 8th theorem on optics, Vitruvius in the definitions, du Bartas in the introduction; Cousin in chapter 12, Dürer in the 10th proposition on optics and in chapter 30, Serlio in chapter 12 and Sirigatti in chapter 18.
Following the first publication of La Perspectivein 1611,a second edition was brought out in 1612, also in London and with the publishing privilege, by Jan Norton.

Jean-Pierre Le Goff (IREM & RDLI-LASLAR,
Université de Caen Basse-Normandie) – 2010


Critical bibliography

J. Baltrusaitis, Anamorphoses ou magie artificielle des effets merveilleux, Paris, Perrin, 1969.

J. Baltrusaitis, Anamorphoses ou Thaumaturgus opticus, Perspectives dépravées, Paris, Flammarion, 1984, vol. 2.

D. Bessot, "Salomon de Caus (ca. 1576-1626) : archaïque ou précurseur ?", D. Bessot, Y. Hellegouarc’h & J.-P. Le Goff (eds.), Destin de l’Art, Desseins de la Science, Caen, ADERHEM/IREM de Basse-Normandie, 1991, pp. 293-316.

J.-P. Le Goff, "Tout ce que uous auez tousiours uoulu sçauoir sur la uie et l’œuure de Salomon de Caus (ca. 1576–1626), et entre autres choses : l’histoire d’un savant du premier XVIIème siècle aliéné au XIXème siècle et un manuscrit inédit (ca. 1625) de Salomon de Caus à la Bibliothèque de Valenciennes (ms. 339)", Circulation, transmission, héritage, Caen, IREM de Basse-Normadie, 2011, pp. 503-543.

C. S. Maks, Salomon de Caus, 1576-1626, Paris, Imprimerie Jouve & Cie, 1935.

A. Marr, "A Duche graver sent for : Cornelis Boel, Salomon de Caus, and the production of La perspective avec la raison des ombres et miroirs", T. Wilks (ed.), Prince Henry Reviv'd : Image and Exemplarity in Early Modern England, London, Paul Holberton Publishing, 2007, pp. 212-238.

L. Morgan, Nature as Model : Salomon de Caus and Early Seventeenth-Century Landscape Design, Philadelphia, Pennsylvania, University of Pennsylvania Press, 2007.

L. Vagnetti, De Naturali et Artificiali Perspectiva (bibliography on perspective). Studi e Documenti di Architettura, 9-10, Florence, Edizione della Cattedra di composizione architettonica IA di Firenze e della L.E.F., 1979 (in particuliar EIIIb7).