Leslie Geddes's book, somewhat misleadingly titled Watermarks, is a focused exploration of the dynamic between artistic representation and scientific inquiry in the Renaissance, which attempts to situate the art of Leonardo da Vinci in the context of the environmental knowledge of the time. The practice of drawing, according to Geddes, offers a key to understanding the complex interplay of aesthetic and practical motives that defined Leonardo's approach to nature; water is an active yet elusive agent that frames the discussion of the book's many interrelated themes, ranging from mechanics and engineering to cartography, optics, and the theory of painting.
A pioneering figure at the intersection of art and science, Leonardo has long been of interest to interdisciplinary scholarship. What sets Geddes's contribution apart from the foundational studies by Paolo Galuzzi, Martin Kemp, and Frank Fehrenbach is the centrality of landscape to her discussion, both as a physical setting for empirical inquiry and an expression of deeper natural processes that spurred Leonardo's intellectual curiosity and artistic imagination. This emphasis is sustained through close analysis of the artist's selected graphic and painted works that reveal the richness of environmental detail that he observed and recorded. For Geddes, Leonardo's drawings present a powerful epistemological tool, an experimental mode of gaining the knowledge of nature.
Water, according to Geddes, brings together different elements in Leonardo's conception of landscape by keeping them in constant flux, as it shapes the visible contours of the earth through the underlying processes of geological formation and erosion. An ability to understand its unpredictable behavior was essential for preventing natural disasters or gaining military and economic advantage. The first part of Geddes's book is concerned with different modes of negotiating this fluid environment explored in Leonardo's technical drawings, situating his method among the architectural and engineering traditions of the time. His sketches show devices for dredging canals and rivers, harnessing and traversing various bodies of water, and instruments to facilitate diving, swimming, and even walking on its surface. Rooted in the artisanal technology of the Renaissance, such designs—often repetitive and impractical, but invariably imaginative and inventive—no longer emerge as works of an isolated genius. They change the perception of Leonardo from a misunderstood visionary to an assured practitioner, ready to put his skills at the service of competing powers that dominated the late fifteenth-century Italian political scene.
The second part, which addresses the role of water as a reminder of the ongoing processes of landscape transformation, furthers the notion that the study of nature for Leonardo was less of a goal in itself than a prerequisite for carrying out concrete practical tasks. His approach to the natural world as a dynamic and historically layered environment had a direct bearing on various artistic practices, including mapping, that engaged him throughout his lifetime. Notable in this respect is the emphasis on the violence of nature that parallels the ferocity of warfare. In fact, the drawing of a collapsing mountain at Windsor, which Geddes interprets as a record of a landslide, may well depict a purposeful explosion, given the presence of a tunnel visible at the lower right with a stair leading to it. Equally interesting is a group of monochromatic sketches, also in the Royal Collection, which are analogous to fieldnotes with textual annotations to provide additional information—such as the subtle effects of atmosphere—that cannot be conveyed by graphic means. Paradoxically, this method shows Leonardo's awareness of the limitations of drawing as a medium for capturing sensory phenomena, which is particularly striking for a leading representative of the artistic culture of disegno.
What this attractive book lacks is an effort to situate Leonardo's real and imaginary geographies in terms of physical place. Typical in that regard is the analysis of the bird's-eye view of the Valdichiana—which, as the juxtaposition with the preliminary study suggests, was probably mapped from Monte Cetona—oblivious to the current appearance of this landscape, radically transformed by the aggressive land reclamation policies beginning in the seventeenth century. Geddes's argument also suffers from the lack of a consolidated discussion of Leonardo's philosophy of nature, scattered through different chapters. The omission of references to the pertinent work by Michel Jeanneret is particularly surprising in this respect. Despite these shortcomings, Geddes's study remains a timely invitation to a close reading of Leonardo's drawings, not as a purely artistic medium but also as a versatile means of engaging with nature.
