Hieronymus Cock’s Baths of Emperor Diocletian (1558) and the Diascopic Architectural Print

At the Royal Academy in London there is an extraordinary architectural publication of overwhelming dimensions.^[1] Composed of twenty-seven large etchings, five smaller cut-out prints, and two letterpress sheets mounted on six pieces of linen, it measures over sixteen metres when placed end to end (figs 3.0–3.6). These individual prints are impossible to take in with a single glance and difficult to comprehend at a distance. Rather, once unrolled, one slowly pans across each composite etching, which are titled in large classical lettering THERMÆ DIOCLETIANÆ, ‘The Baths of Diocletian’, the largest bathing complex of the ancient world.

Printed in Antwerp in 1558 they together form a complex visual scheme. Take one of the largest prints of the series, measuring over three metres in length (fig. 3.6). The immensity of the structure is immediately striking. Lofty vaulted rooms and vast open areas dwarf small groups of figures. An accompanying scale and measurements in feet (down to the minute) reiterate the imposing size of the building, and attest as well to this representation’s veracity. Above the scale, a short label clarifies that the viewer is looking across the middle of the bath complex, longitudinally from east to west. This interior side view reveals a series of spaces that unfold horizontally. As one surveys this continuous architectural progression, its splayed one-point perspective pulls the viewer inward. Heavy shadows additionally give the structure depth, which seems to otherwise float in the abstract space of the page without a background or horizon line. The representation draws the eyes across the expansive structure as well as into its constituent spaces. It even propels the viewer’s gaze through the walls of the ancient complex, which have been sliced vertically, straight through its masonry and concrete core. In one etching, which depicts the building laterally, this cut even extends underground to expose a system of water pipes (fig. 3.4). It also continues rearward, peeling away part of the main structure to expose a quadrant of a domed bathing room labelled balneum, complete with spiral staircase and octagonal coffering.

More than merely unusual images combining cross-section and perspective, this essay argues that these horizontal views constitute what I am terming a diascopic way of depicting architecture. Derived from the Greek prefix dia- (through and across) and verb skopein (to see, view, look, examine, behold, and consider), the term encompasses both a method of representation and a mode of viewing. As a technique, it emerged from the experimental drawing practices of early modern architectural culture and the study of antiquity. It relied on surveying technology refined by military engineers and cartographers, and it was partially inspired by panoramic city views. At the same time, unlike later circular painted panoramas that proliferated in the nineteenth century, the prints of the Baths of Diocletian do not attempt to represent the totality of a view or to create an immersive environment. They instead force the viewer to pan each of their images, looking across and through the ancient structure at a variety of different points. The building is thus progressively revealed in scroll-like fashion as a series of exceedingly long, vertical planes that stretch the field of vision and expand the realm of the visible. Diascopic representation in this manner acted as a tool of dissection that clarified the complex ancient structure for the observer. It was also an instrument of resurrection, augmenting traditional methods of reconstruction to breathe new life into the heavily ruined edifice. By mobilising this new means of envisioning and experiencing antiquity, the makers of these prints also created an architectural monograph that broke with the traditional codex format and explicitly sought to preserve a work of architecture through the modern medium of print. These etchings of the Baths of Diocletian therefore herald the emergence of a new form of architectural publication and mode of visualisation, one which harnessed the potential of the near-continuous page.

Reconstructing the Baths and Enlivening Antiquity

Entitled Thermae Diocletiani Imp. (‘Baths of Emperor Diocletian’), the publication consists of five views of the baths: a section from south to north through the middle of the structure (fig. 3.5) and another from east to west (fig. 3.6), as well as a southern exterior elevation of the central block (fig. 3.2), one from the western side (fig. 3.3), and a third from the east (fig. 3.4).^[2] There is also a plan of the complex and two etchings of architectural elements labelled with letters that key them to details in the other prints (fig. 3.1). In the Royal Academy copy, these sheets are pasted alongside two pages of letterpress text, but in other examples, this bifolium serves as an introduction to the publication. At least twenty-one complete or partial sets survive today.^[3] Most of these are folded up and bound into books, often in different arrangements, while a few are preserved as rolled-up scrolls.^[4] Some may have originally been mounted on walls, like many other large-scale prints, but little physical evidence of this practice survives today. Only examples at the Royal Academy, Herzogin Anna Amalia Bibliothek, Bibliothèque de l’Arsenal, Kungliga Biblioteket, and Kunsthistorisches Museum feature five additional etchings that were cut out, mounted on paper, and connected by a hand-drawn, measured line. This augmentation may have been limited to only deluxe editions, or perhaps, after proving too laborious, it was simply abandoned for the sake of economy.

This monumental publication was a collaborative effort. Printed by Hieronymus Cock, whose Aux Quatre Vents (‘At the Sign of the Four Winds’) press became one of the largest print publishing houses in Europe, it was financially supported by Antoine Perrenot de Granvelle, the wealthy Bishop of Arras. Granvelle commissioned the architect Sebastiaan van Noyen to produce drawings of the Baths of Diocletian, which the brothers Johannes and Lucas van Doetecum transformed into etchings, and Cock enlisted the poet and humanist Cornelis de Schrijver (also known as Cornelius Grapheus and Scribonius) to write a short Latin introduction describing the baths and their history, as well as a laudatory dedication in verse to the bishop. As Edward Wouk has shown, Granvelle played a critical role in Hieronymus Cock’s early success as a publisher.^[5] He not only helped bring Mantuan engraver Giorgio Ghisi to Antwerp, whose technical skill and knowledge of Italian art Cock quickly exploited, but he also provided funding for the publisher’s first major work, a set of etchings printed in 1551 and entitled Praecipua aliquot Romanae antiquitatis ruinarum monimenta… (‘Some particular monuments among the ancient Roman ruins’, also known as the Large Book of Ruins).

Sponsorship of such projects was essential. While the market for antiquarian publications in the Low Countries had grown substantially by the mid-sixteenth century, in 1546 Pieter Coecke van Aelst still lamented that because ‘lovers of ancient architecture are very limited’, it would be difficult for him to recoup the substantial production costs of his Flemish translation of Sebastiano Serlio’s book on antiquities.^[6] Granvelle was a natural patron for such work. Active in Roman antiquarian circles, he sought out antiquities and amassed a substantial art collection, which he displayed in a classicising gallery added to his Brussels palace. He was also a collector and connoisseur of prints, who used his sizable fortune to assemble a large library including many architectural books.^[7] Like other ambitious politicians and prelates, Granvelle’s patronage of the arts and promotion of antiquity was at the same time a means of self-aggrandisement. The 1558 Baths of Emperor Diocletian indeed proudly proclaims in its introduction that Granvelle had brought the structure ‘to light, at his expense, and with passion for the study of venerable antiquity’.^[8]

The vision of antiquity that Cock propagated with Granvelle’s support was by no means uniform. The Large Book of Ruins, for example, contains twenty-four etchings of a variety of deteriorating ancient Roman monuments (fig. 3.7).^[9] Inspired by earlier drawings made in Rome by Netherlandish artists such as Maarten van Heemskerck, as well as contemporary landscape paintings—the type Cock likely produced before turning to printmaking—these views depict the ancient city as a decaying corpse, littered with partially collapsed monuments covered with vegetation.^[10] Sketchy, acid-etched lines executed by Cock himself amplify the sense of ruin and evoke the atmospheric effects of decomposition. The result is a series of prints that render once pristine architecture progressively incoherent, transforming it into what others have described as picturesque pure form suited for reuse and formless images that spurred creative engagement.^[11] Although the title page of the publication promises verisimilitude, and each print is identified topographically (albeit sometimes erroneously), the prints privilege effect over content.

The Baths of Diocletian (fig. 3.7), for instance, are shown in this earlier series through an impossible splayed perspective which removes still-extant vaulting to expose an empty ruinscape where the caldarium, tepidarium, and frigidarium once stood. This is in stark contrast to the 1558 etching of the same series of spaces (fig. 3.6). Here the individual parts of the ancient structure, down to the architectural sculpture, have instead been restored. The Van Doetecum brothers carefully incised the architecture into the waxy ground of the copper etching plate with compass and rule and finely rendered with horizontal, vertical, and diagonal hatching. Only the interior masonry, exposed by the sectional cut, is articulated with small irregular lines. These methods of delineation and shading, which at times appear almost like engraving with a burin, contrast with those of the earlier print, where no two etched lines are parallel and the crumbing masonry merges with the rugged terrain below.

In the 1551 print, Cock thus exaggerated the ruinous nature of the baths. He also accentuated its darkness, placing two men frantically fleeing another pair wielding swords. Ruins had long been seen as unhealthy, nefarious places that were products of violence and avarice.^[12] The Baths of Diocletian was even said to be inhabited by the devil until Filippo Neri expelled him in 1551.^[13] In Cock’s later publication, the structure is cleansed of this architectural and human disorder. Panning the sequence of spaces, the viewer instead encounters tidy groups of figures: a martial cavalcade, two men walking in conversation, and another pair gazing and gesturing upward (fig. 3.8). These figures mirror the surrounding architectural order, while also encouraging the viewer to mimic their actions and follow their movements to better understand the building around them.

This reconstructive aspect at work within the 1558 prints is in large part the product of Sebastiaan van Noyen, a military engineer and architect who served emperors Charles V and Phillip II before his death at the age of thirty-four in 1557.^[14] Originally from Utrecht, he worked alongside established Italian military architects Donato de Boni di Pellizuoli and Giovanni Maria Olgiati, before rising to the rank of architect-general of imperial fortifications. In this role, he supervised the construction and renovation of fortifications throughout the Low Countries.^[15] Krista de Jonge has suggested that Van Noyen likely travelled to Rome around 1550, and upon his return, possibly designed the garden gallery for Granvelle’s palace in Brussels (c.1551–54), which took inspiration from the courtyard of the Palazzo Farnese.^[16] The introduction to the 1558 publication tells us that Van Noyen, at the instruction of Granvelle, had ‘measured and drawn these ruins’ and ‘precisely recorded [them] from life (ad vivum) from the ground upward’.^[17] These written assertions of veracity and autoptic study were part of a growing trend in sixteenth-century print culture, one that sought to affirm the objectivity and indexicality of mechanically reproduced images, be they portraits, maps, or botanical illustrations.^[18] The etchings of the Baths of Emperor Diocletian reiterated these claims of accuracy throughout with measurements in palmi, digiti, and minuti. Each also features a scale in pes maior, despite the fact these images cannot yield accurate measurements due to their perspectival rendering.^[19] One of the etchings (fig. 3.3) even includes a larger ruler labelled ‘the genuine scale in feet (pedes) with twelve fingers (digiti) that Sebastiaan van Noyen measured the whole work’, which does not correspond to others provided.^[20] Measuring thirty-two and a half centimetres in length, it is instead exactly the same size as the French Royal foot. This metrical dissonance is perplexing. While the 1:1 scale ruler should enable the user to translate the prints into any unit of measure, making them universally comprehensible, the numerical figures provided in the etching appear to conform instead to the ancient palmus, as understood in the Renaissance, while those of the introductory text are equivalent to the Roman pes.^[21] The architect thus converted his survey into an ancient unit of measure, perhaps to render it historically authentic.

It is also likely Van Noyen relied in part on the work of others. This was not uncommon. Hieronymus Cock, in fact, also published around 1558 an etching of the Mausoleum of Halicarnassus that is nearly identical to the reconstruction produced by an artist in the circle of Antonio da Sangallo the Younger.^[22] Even in Rome itself, artists and architects continually copied drawings of ancient Roman buildings throughout the sixteenth century.^[23] Documenting the entirety of the Baths of Diocletian—an immense structure so incomprehensible and difficult to measure in its ruined state that Sebastiano Serlio explicitly chose not to reconstruct its elevation in his book on antiquities—would have been a herculean task requiring a team of workmen.^[24] Just such an undertaking was afoot in Rome at the same time Van Noyen visited the city. From the 1540s onward, a group of mostly French-speaking draftsmen produced hundreds of minutely detailed surveys of Roman buildings, many preserved today in the so-called ‘Codex Destailleur D’ and other related albums.^[25] These include sketches of the Baths of Diocletian in section and elevation, copiously measured in French feet, keyed with letters to nearby architectural details, and drawn over three attached pieces of paper (fig. 3.9). Executed in pen atop faint black chalk outlines, these drawings closely recall the diascopic images of the Baths of Emperor Diocletian.^[26] In fact, they appear almost like preparatory studies for the later etchings. It is impossible to know if Sebastiaan van Noyen helped created these drawings; he certainly would have had contacts with the French-speaking community in Rome through Granvelle, who since 1540 had been the bishop of the Burgundian town of Arras. Yet Van Noyen did not simply reproduce these precise surveys. He instead transformed this raw material, adding ornament, sculpture, and perspective, while also omitting incongruous architectural details and superfluous measurements. The architect therefore created something distinctly new, which was grounded in archaeological study, but not purely antiquarian. At some point in the 1570s, Andrea Palladio followed a comparable procedure, using drawings he had assembled in Rome three decades earlier to create sectional views of the Baths (fig. 3.10). But in the case of these drawings, which Palladio intended for publication, the architect also looked to Cock’s monumental prints for inspiration, copying some of its details exactly. A few of the drawings even attempt to rival the scale of the etchings, stretching over a metre and a half in length.^[27]

Despite their similarities, the Destailleur drawings are also significantly different from the reconstructions of Van Noyen in their employment of a rigorously orthogonal method of representation. Scholars have often highlighted the use of orthography—the rendering of a structure’s exterior or interior as a two-dimensional vertical plane without perspectival distortion—as indicative of the rise of objectivity in Renaissance architecture.^[28] It has also been tied to the writings of Alberti and Raphael, who claimed architects should create orthogonal drawings with parallel and perpendicular lines, rather than painterly perspectives for purposes of clarity and mensuration. But as others have noted, architects rarely treated these modes of representation as oppositional.^[29] It is a modern teleology that drawing progressed from pictorial practice to mathematical science. Rather, artists and architects throughout the Renaissance simultaneously embraced a wide variety of methods of representation for different purposes, such as the rendering of interiors, where orthogonal projection most clearly met its limits.^[30]

In the case of the Baths of Diocletian, perspective served as an essential tool for the documentation and reconstruction.^[31] Already in the late fifteenth century, an unknown draftsman created a series of perspectival drawings dissecting the spaces of the ancient structure (fig. 3.11).^[32] Some of these take the form of horizontal views, somewhat akin to those produced by Van Noyen over a half century later. Others peel away the columns and walls of the baths, leaving a vestigial plan to elucidate the structure’s interior. In doing so, these drawings also implicitly reveal the procedure by which the building came into being from abstract plan to material edifice. Later architects elaborated on this process. For example, a member of Raphael’s circle (known as Master C of 1519), in an album of drawings now in Vienna, achieved this effect through a process of selective ruination (fig. 3.12).^[33] This technique of decortication, which had been pioneered by Giuliano da Sangallo, enabled the draftsman to render the complex spatial qualities of the different bathing halls. Each highly finished interior rendering, moreover, is labelled with a letter corresponding to a location on an accompanying ground plan. These topographic reference points transformed the cut-away views into a sequence of spaces, giving the ichnographic plan material presence and empowering the viewer to move virtually through the ancient structure. Drawings such as these thus anticipated the diascopic reconstructions of van Noyen, which similarly offered the viewer an active perceptual experience.

Like many ancient Roman monuments, the Baths of Diocletian fell into ruin over time.^[34] While in the 1440s Poggio Bracciolini still marvelled at its ‘numerous columns, many of great size, and various kinds of marbles’, by the sixteenth century the marble-clad brick and concrete structure stood mostly denuded and covered with vegetation.^[35] The Baths of Emperor Diocletian, in contrast, presents an image of antiquity reborn, seemingly brought back to the moment of its dedication in 306 CE, complete with elaborately adorned coffered vaults and a profusion of statuary. This regenerative effect, however, is not as simple as it first appears. As one looks closely across these etchings, the appearance of historical unity and aesthetic homogeneity is, in fact, disturbed. In the two north-south sections of the baths (figs 3.4 and 3.5), figural sculpture only turns up on the right-hand side of the building. The switch is striking. On the natatio wall, empty niches and aedicules suddenly are populated with a variety of gigantic protruding statues, evoking a theatrical scanenae frons, while in another print an Emperor in a quadriga participates in a triumphal procession (fig. 3.13). The creators of these etchings may have employed this representational technique to reveal different layers of information, with one side clarifying the architectural form and the other offering the decorative program, albeit one without a clear iconography. It may perhaps also illustrate alternative schemes for reconstruction. Either way, the visual dichotomy calls attention to the artificial nature of the image, exposing it as a work of interpretation.

Looking still closer at the largest etching (fig. 3.4), another possible reading emerges. Examining this image from left to right, one first encounters an aqueduct and cistern below. The accompanying text describes how water is first diverted to this reservoir and then flows through channels to the baths. Following this fresh water, one next comes upon a semicircular bathing hall with large basins emptying into waste water pipes. A schematic representation of the complex ancient hydraulic infrastructure then continues underground, drawing the eye across the entire print—some three metres—to a symmetrical bathing hall at the far end.^[36] Yet, whereas the basins of the first space stand empty, like the architectural niches above, here figures suddenly appear. At left, a younger and older woman bathe while engaging in conversation, and to the right, a boy holding a pouch of oil (known as a guttus) prepares to scrape the skin of an older man with a strigil as their tub fills with water from animal-head-shaped spouts (fig. 3.14). On the wall behind them, a towel is hung alongside other bathing instruments. As one visually traverses the etching, the reconstruction is thus progressively enlivened: first by simulating the progression through architectural space with the aid of perspective; then through the appearance of moving water and figural sculpture; and finally, with the emergence of human figures inhabiting the structure and caught in the ancient act of bathing. These partially nude men and women, in turn, activate the surrounding over-life-sized statuary, making the pagan likeness appear to come to life. The older woman, for instance, looks up and gestures to one of the statues, who returns her gaze and stretches out his hand. These stone or bronze sculptures in fact seem to move more than their miniature human analogues below. Even the architectural vault above appears to come to life with foliage sprouting from the heads of outstretched eagles.

Antiquity here is not just reconstructed, but reanimated. This process of vivification, moreover, is not just superficial artistic elaboration. The bathers are in fact an antiquarian quotation, modelled on a woodcut published in Fabio Calvo’s 1527 Antiquae urbis Romae (fig. 3.15), and later reprinted by Guillaume du Choul in his 1554 book on ancient bathing and exercise.^[37] The choice to label this structure balneum, a Greek term for modest private baths, similarly comes from this print. Cornelis de Schrijver additionally utilised Du Choul’s work when crafting his Latin introduction to the Baths. He also cites passages from Vitruvius and Alberti as well as Hubertus Goltzius’ 1557 book of imperial effigies: one of the prints (fig. 3.6) even contains a medal of Diocletian copied directly from this contemporary publication.^[38]

These different forms of erudite visual and textual quotation would have appealed to educated viewers skilled in intertextual study. For this audience, the text of the publication further emphasised the project of enlivening antiquity. In his dedicatory poem, De Schrijver chronicled how Granvelle, grieved at the fate of the Baths of Diocletian, which stood as a ‘collapsed ruin’ and ‘a sad rotting cadaver’, ‘partially buried’ in a ‘squalid tomb’, until he ‘discovered a remedy’ and ‘resurrected it from the grave’. These analogies, which draw on the established humanist tropes of building-as-body and Rome-as-corpse, emphasised the corporality of the ancient structure. Granvelle, according to the laudatio, ‘awakened alive again’ what had ‘gradually fallen from memory’, creating a restored building that would ‘remain standing through the ages’. What once had ‘fallen to the ground under its massive weight’, now again ‘equalled vast mountains…rising to the sky in renewed form’. Through this publication, the Baths of Diocletian, ‘built from the sacred sweat of Christians’, were literally reborn and would endure the ravages of time, never again falling to ruin. For this achievement, the author proclaims, Granvelle’s name, like the resurrected building, will resound for centuries.^[39]

The patron of this project is thus celebrated as the restorer of antiquity. Claiming it as his own, Granvelle promoted an image of cultural superiority, antiquarian erudition, and piety, perhaps as a means of ingratiating himself with the newly crowned Emperor Philip II with whom he had recently fallen out of favour.^[40] This triumphant appropriation of antiquity is reiterated in a pair of monumental inscriptions hovering above the baths (fig. 3.6). Both written in Latin and rendered in Roman square capitals, one commemorates the building’s ancient dedication, the other its modern recreation. Treated as equal laudatory acts, the latter inscription specifically celebrates the Bishop of Arras, for having had the Baths of Diocletian ‘measured and drawn’, ‘engraved on copper’, and ‘published’ to ‘protect them from inevitable destruction’.^[41] Granvelle therefore had not only breathed new life into this ancient edifice, but through mechanical reproduction also preserved it for posterity.

The diascopic etchings, produced by the Van Doetecum brothers after drawings by Van Noyen, ensured the baths would endure forever in reconstructed form. A detailed examination of these printed images, though, calls these celebratory claims into doubt, exposing the tensions of reconstruction and raising the question of whether antiquity had actually been revived. On the surface, the elaborate architecture of the baths appears pristine. The bathing figures, unlike the others depicted (fig. 3.8), are also clearly ancient, signifying that the passage of time itself has been erased. This semblance of a restored, revivified past, however, is not universal. The aqueduct that brings water to the baths is actually severed and vegetation sprouts from various walls (fig. 3.16). At the edges of three combined prints (figs 3.2, 3.3, and 3.5), small pasted etchings give the impression of an abandoned building falling into ruin. The boundaries here between real and imaginary are blurred. Is this the Baths of Diocletian as it was, as it is, or a dehistoricised hybrid that can only exist on paper? While at times this ruination reveals additional information, like the early Master C drawings (fig. 3.12), in other places it obscures the architecture. Looking across these etchings, the ancient structure seems rather to oscillate from present to past and back again, making visible the implicit process of reconstruction. It also foreshadows future decay, insinuating that underneath this resurrected building lies a derelict structure, the type Cock had already illustrated (fig. 3.7). This visual temporal dissonance seems to highlight Renaissance anxieties of enlivenment. While antiquity may appear reborn, the etchings suggest that Granvelle, even with a team of artists, architects, and humanists, could never fully bring the ancient baths back to life. It was always already a ruin.

Toward a Diascopic Architectural Print

The Baths of Emperor Diocletian was unlike any other architectural publication produced in the Renaissance. Its diascopic etchings, nevertheless, were grounded in a variety of intertwined traditions, developments, and viewing practices linked to various types of large-scale drawings and prints. Graphic representations of architecture, for example, had been produced on a grand scale across Europe since the late medieval period.^[42] Thirteenth-century drawings for the facade of Strasbourg Cathedral, some of the earliest that survive, already measure around three and a quarter metres.^[43] Some later examples, such as those for the north tower of St Stephen’s Cathedral in Vienna, stretch to five metres in length.^[44] These designs were typically rendered on multiple pieces of parchment assembled into scrolls, a format ideally suited for the depiction of vertiginous towers, belfries, and sacrament tabernacles.^[45] In the case of twin-towered Gothic facades, this procedure was simply duplicated. The draftsman of a huge drawing for Cologne Cathedral, made some time after 1290, joined two largely symmetrical drawings, executed on separate rolls, to produce a single elevation made of eleven large pieces of parchment.^[46]

Already in the late fifteenth century, Northern engravers such as Alart Duhameel, Wenzel von Olmütz, and Master W with the Housemark, began to create large prints in the tradition of these drawings. Depicting Gothic towers, tabernacles, baldachins, and micro-architectural monstrances, these engravings, which perhaps served as workshop models, were often printed with multiple plates on multiple pieces of paper (fig. 3.17).^[47] Printmakers in Italy, on the other hand, rarely produced similar multi-sheet architectural prints.^[48] This is despite the fact that Italian architects, like their Northern counterparts, continued to create enormous presentation drawings throughout the Renaissance.

Beyond the realm of books, the production of discrete composite woodcuts and engravings of other subjects was in fact quite common in the Renaissance. Individual engravings and etchings were limited by the size of copperplates, width of rolling presses, and dimensions of available paper.^[49] While single-sheet woodcuts could be larger, even the most extraordinary examples, such those of Jacopo de’ Barbari’s enormous view of Venice (1500), rarely surpass a metre in length or width.^[50] Printmakers transcended these technical constraints through a process of assembly, creating works of immense size from multiple printed sheets typically affixed to cloth.^[51] The largest of these, the Triumphal Arch of Emperor Maximilian (1515–17), consists of 195 blocks printed on thirty-six pieces of paper, which measure, when all combined, approximately three and a half by three metres.^[52] Works of this scale were intended to be mounted on walls and became part of the architectural environment. Some, such as Dürer’s contemporary four-piece Great Column woodcut (1517), were even designed as a form of wallpaper, which could be painted and gilded (fig. 3.18).^[53] Rising to over one and half metres in height and rendered in perspective, this elaborate full-scale fictive column, supported by two putti and decorated with ram’s heads, winged female creatures, and a garland holding satyr, transformed print into an architectectonic medium, albeit an exceedingly ephemeral one.^[54]

Prints also were easily assembled into horizontal scrolls of seemingly unlimited length. In 1576, for example, Girolamo Muziano published a series of 130 etchings of the Column of Trajan, which when combined form a continuous fifty-six-metre-long frieze that could be bound and folded, rolled up, or even—according to the original copyright application—pasted onto a wooden model of the monument.^[55] Biblical, ancient, and contemporary processions and triumphs were ideally suited for this format.^[56] Already beginning in 1512, the Holy Roman Emperor Maximilian sought to promote his claim to authority by sponsoring the production of a spectacular fifty-four-metre Triumphal Procession.^[57] Robert Péril and Nicolas Hogenberg commemorated the 1530 Bologna coronation of Emperor Charles V in a set of similar processional woodcuts and etchings, and Jörg Breu the Elder even memorialised the emperor’s return to Augsburg the same year in a multipart woodcut frieze.

These prints, despite their lack of architecture, provided a clear template for the Baths of Emperor Diocletian, one with strong imperial connotations. In fact, the closest analogue to these etchings is a monumental print of the Brussels funeral procession of Charles V (fig. 3.19).^[58] Published by Hieronymus Cock with the assistance of Christophe Plantin in 1559, and executed by the Van Doetecum brothers, it is composed of thirty-four etched plates as well as letterpress text issued in six languages. The prints, which extend in total to some eleven and a half metres, depict dignitaries and courtiers solemnly parading towards an elaborate catafalque. These figures are labelled in Italic script and above them is a large Latin epigram rendered in classicising Roman letters, just like in the etchings of the Baths of Diocletian.^[59] These commonalities of format and style suggest not only a common artistic origin, but also a shared tradition of representation tied to regal displays of power. Processions were a fundamental means by which rulers demonstrated sovereignty and physically enacted their authority. Panning these prints, the viewer follows the movement of the retinue, virtually enacting the process of procession. This visual locomotion thus activates these images and actualises imperial ritual, much like similar contemporary painting, fresco, and tapestry cycles, as well as architectural friezes, such as the 150-metre-long Roman triumph executed in sgraffito on the Dresden Stallhof and Langer Gang (1586–1588).

The diascopic prints of the Baths of Emperor Diocletian engaged these established viewing practices and harnessed the associative meanings embedded in their horizontality. They were part of a network of prints that projected, through the act of scrolling, a triumphal image of imperium. As architectural representations, however, they differ fundamentally from contemporary processional prints due to their lack of narrative. Without a beginning or end, these etchings of the Baths of Diocletian have no clearly defined sequence. This absence of explicit directionality is compounded by their discontinuity. Rather than looking across a single, continuous, sweeping view of the structure, the publication instead provides as series of sequential cuts across the same structure. The viewer does not progress from start to finish, but rather gradually explores each image transversely. The etchings, in this way, look to other parallel traditions, such as panoramic maps.

Artists throughout the Renaissance created large composite topographic prints. Some of these depict contemporary events, most notably battles and sieges, but many others take the form of urban maps.^[60] Already in the late-fifteenth century, the engraver Francesco Rosselli produced a series of bird’s-eye views of Florence, Pisa, Rome, and Constantinople, the largest of which consisted of twelve sheets and measured over a metre and a half in length.^[61] Building on a tradition of painted cityscapes and a practice of measured surveying, these and similar later maps, such as Barbari’s Venice, created all-encompassing views rendered from an aerial perspective.^[62]

An alternative approach also developed in the 1480s. Rather than depicting cities from above, these images, such as Erhard Reuwich’s woodcut of Venice (fig. 3.20), present a horizontal panorama. Published along with other smaller city views as part of Bernhard von Breydenbach’s Peregrinatio in terram sanctam (1486), this long woodcut does not project a single cohesive urban image, one legible from afar. The city, bustling with human activity, instead unfolds gradually as if the viewer, standing atop the mast of a tall ship, sails across the Venetian lagoon. While Reuwich may have relied in part on Italian precedent, it was in Northern Europe that this mode of representation become pervasive.^[63] A view of Antwerp dated 1515, for example, depicts the city expanding across the Scheldt, and in 1531, Peter Quentell published a similar nine-block woodcut by Anton Woensam of Cologne spreading out along the banks of the Rhine.^[64] Numerous other examples followed, all of which depict jagged cityscapes, dotted with pointy Gothic towers, set against exceedingly flat terrain.^[65] Rather than gazing deeply into urban space, each city becomes a flattened profile seen from a low vantage point. These sweeping horizontal views, as Lucia Nuti has observed, were deeply rooted in a culture of seafaring, one that relied on knowledge of coastlines for purposes of navigation. Sailing from the shore, cities and geographical features alike are reduced to their most basic profiles, overtaken by the all-encompassing marine horizon. Artists even illustrated schematic topographic silhouettes in navigational manuals, known as rutters, such as the guide to Baltic Sea routes first published in 1544 by painter and mapmaker Cornelis Anthonisz (fig. 2.21).^[66] In the Low Countries especially, artistic and cartographic activities were integrally linked in the sixteenth century. Along with the omnipresent flatness of land and sea, they helped form a distinctive Netherlandish visual culture, one that viewed the world in profile and panoramic vista.^[67]

Artists from the Netherlands, such as Maarten van Heemskerck and Herman Posthumus⁠, also brought this way of seeing to Rome, creating sweeping city views already in the 1530s.^[68] Expanding onto multiple sheets of paper, these drawings attempted to encompass the whole of the urban landscape from a single elevated vantage point. In Posthumus’s view from the Capitoline Hill (fig. 3.22), the two-dimensional projection stretches the visual field almost a full 360 degrees, spanning from the Ponte Santa Maria (now the Ponte Rotto) on the left, to the Arch of Janus Quadrifons on the right. These types of topographic views, for which the Netherlandish artist Anton van den Wyngaerde would become internationally known in the 1560s, also shaped the depiction of architecture.^[69] Herman Posthumus, when recording the Baths of Diocletian, for example, stood at the eastern corner of the complex and began to draw what remained of the central block. But rather than stopping there, he continued to pan the structure, turning the sheet of paper over to record the outer perimeter wall (fig. 3.23). Like contemporary printed and drawn city views, the artist broadens the cone of vision in order to capture the ancient structure in its entirety from a single viewpoint.

The images of Sebastiaan van Noyen for the Baths of Emperor Diocletian are grounded in these traditions. Their elongated horizontal format, like contemporary panoramic city views, splays the architecture along an unending horizon, pushing their views beyond the limits of peripheral vision. The longest etchings are in fact so wide that there is no single, universal vanishing point. The external focal point from which the viewer could take in the entire image, moreover, is too far away to perceive perspectival accuracy. Geometrical construction instead gives way to pictorial description. These prints thus do not function like traditional images constructed with one-point perspective. They do not project an internal spatial unity, comprehensible from a single, fixed viewpoint, nor do they immobilise the eye of the viewer in space. Rather, just as in the panoramic cityscapes, the shallow, outspread perspective promotes horizontal movement across the diascopic image, thereby engaging an embodied gaze that operates in real space.

The Baths of Emperor Diocletian etchings also condensed other interlinked architectural and cartographic activities, most notably the spatial practices of surveying that had developed in the Renaissance. Using instruments of navigation, such as the magnetic compass and cross-staff, as well as geometrical systems of triangulation, draftsmen in the sixteenth century created topographic maps and highly detailed architectural surveys.^[70] For a military architect such as Van Noyen, these activities would have been common practice. The design and construction of fortifications typically began with precise topographical surveying. Urban cartography, in fact, was often the result of defensive works.^[71] Modern warfare also instrumentalised surveying for the purposes of tactical preparation and cannon bombardment.^[72] It may very well have been because of his measuring and surveying skills that Granvelle sent the young architect to document the remains of ancient Rome.

The representation of space was also integral to the creation of a diascopic mode of visualisation. As discussed, the etchings of the baths were part of a tradition of architectural rendering stretching back to the fifteenth century that combined section and perspective. The ancient author Vitruvius, in fact, had described a form of perspective (scaenographia) in his brief discussion of methods of architectural representation. Placed alongside plan (ichnographia) and elevation (orthographia), scaenographia consisted of ‘the shaded rendering of the front and receding sides, which converge to a point’.^[73] Since Vitruvius did not discuss sectional projection, some sixteenth-century writers recast scaenographia as sciographia, meaning rendered with shadows. Daniele Barbaro in his 1556 Italian edition of Vitruvius, argued that sciographia, specifically here the creation of shaded profiles, enabled ‘the architect, like the anatomist’, to understand ‘all exterior and interior parts’ and the spatial relationship of ‘every member’.^[74] While Barbaro sought to promote orthogonal section over perspective in architectural practice, the lexical ambiguity between scaenographia and sciographia supported the continual conflation of these two modes of representation throughout the Renaissance.

In the case of the Baths of Emperor Diocletian, Van Noyen cut the building with seemingly surgical precision along the median plane from front to back (fig. 3.6) and twice transversely (figs 3.4 and 3.5). Once divided, the resulting sections were then given spatial depth through shading and perspective. These visual effects transform the analytical into the experiential, simulating the unfolding of architectural space as the viewer’s gaze is slowly pulled inward. Bernardino Amico, who published similar sectional perspectives populated with small-scale figures (fig. 3.24) in his treatise on the Holy Land, first printed in 1610, believed this combination of representational techniques amplified the power of flat images since ‘things united have greater force’. He also urged the viewers of his perspectival engravings to look at them with one eye closed from different angles. This, he argued, would make the buildings materialise from the page, actualising these distant sacred sites and enabling virtual pilgrimage.^[75]

These representations also recall the three-dimensional wooden models of holy monuments that Amico and others produced for the faithful. Like the engravings, the small objects permitted the viewer to understand the structure from multiple angles, and walls could even be removed to reveal interior views. Such physical models were a common feature of Renaissance architectural culture. They aided architects in the process of design and patrons in the act of adjudication. Like the diascopic prints of the Baths, they enabled viewers to scrutinise a building’s architectural form and envision its spatial qualities. Some models, such as one built of brick in 1367 for the construction of Florence Cathedral, were even large enough to simulate the physical experience of an architectural interior. Antonio di Vicenzo’s one-twelfth scale brick and plaster model of San Petronio in Bologna, made in 1390, was itself almost the size of a small building, measuring over fifteen by eleven metres.^[76] Some wooden models also approached monumental dimensions: most famously, Antonio Labacco directed from 1539 to 1546, the creation of a gigantic model of new St Peter’s in Rome (measuring 7.36 x 6.02 x 4.68 m), after designs by Antonio da Sangallo the Younger.^[77] Executed at 1:30 scale, the model replicated the entire structure including its decorative scheme. It even simulated building materials with paint and approximated natural lighting effects, much to its detriment according to Michelangelo.^[78] This large model could also be split in half, producing an effect akin to the diascopic views of van Noyen but in three dimensions. Like scrolling the prints in real space, the wooden model enabled the viewer, as they physically moved across the interior, to see through the structure, gaining a deeper understanding of the building with each successive step.

Drawings and prints could only ever approximate the spatial and experiential effects of a model. Sectional perspectival views nevertheless came close. Large examples, such as a parchment drawing by Juan Guas for the capilla mayor of San Juan de los Reyes in Toledo (c.1485–90), measuring almost two metres in height and perhaps created for Queen Isabella I of Castile, gave the viewer the impression of entering into a miniaturised fictive space. In this case, the effect was heightened by the low perspective, detailed sculptural program, and carefully delineated stonework.^[79] Baldassare Peruzzi, in an even larger drawing for San Petronio in Bologna (1522–23), elaborated on these representational techniques.^[80] Depicting his proposed addition to the basilica, this perspectival rendering selectively cuts away exterior walls and interior piers—at different points both vertically and horizontally—to reveal a massive, classicising, domed crossing and attached sacristy. Opened up for the viewer, the colossal interior space evokes the vaulted halls of Imperial Roman architecture that the architect had closely studied.

The vast scale of Peruzzi’s proposed structure, like the etchings in the Baths of Emperor Diocletian, is further emphasised by groups of diminutive figures seen from above. These human elements make the drawing more than just a graphic substitute for a physical model. They create the impression of an actualised building, just like Amico’s Holy Sepulchre or Van Noyen’s Baths. This is also true of Giovanni Caroto’s 1540 reconstruction of the Roman theatre of Verona (fig. 3.25). In this large, fold-out woodcut, the masonry of the imagined structure is peeled away to reveal the ancient monument. At the bottom, water gushing from drain spouts and a small man rowing a boat enliven the image.^[81] These examples attempt not just to expose structures through pictorial techniques, but to make them come alive through the insertion of human figures. They share, in this way, a deeper connection with the prints of the Baths. They also recall the densely populated urban views discussed earlier, some of which even claim to be ad vivium, meaning not just accurately taken ‘from life’, but made ‘lifelike’.^[82] All of these cases, as well as the processional prints examined earlier, sought to give the impression of lifelike reality, even while expanding the realm of the visible.

It was from this rich, interconnected network of graphic material that a diascopic mode of representation emerged. The product of contemporary print culture, cartographic activities, and architectural practice, as well as traditions of representation that developed north and south of the Alps, Cock’s prodigious publication pioneered a new manner of visualising architecture. It was a method of illustration that emphasised architectural corporality and propelled the embodied gaze of the viewer. Since it could only exist at a large scale, this diascopic method would never become commonplace, especially in the realm of print. The Baths of Emperor Diocletian etchings were by their nature exceptional.

The Life of the Baths of Emperor Diocletian

It is unknown how many copies Hieronymus Cock produced of the Baths of Emperor Diocletian, which like many contemporary printed works was protected by a royal privilege. Two states exist: one with and one without the publisher’s address at the bottom of the etchings.^[83] Volcxken Diericx, Cock’s partner and wife, appears to have continued to use the plates after the printer’s death in 1570, but by this point in time they were heavily oxidised.^[84] When the contents of the Quatre Vents press were eventually sold in 1601, the battered copper plates were dispersed and at least one of them became support for a painting.^[85]

Unlike Cock’s Large Book of Ruins, which Jacques Androuet du Cerceau, Battista Pittoni, and Vincenzo Scamozzi almost immediately plagiarised, only Sebastiaan van Noyen’s plan was copied by another engraver.^[86] Other prints of the bath complex, nevertheless, began to circulate in the sixteenth century. In fact, in the same year that the Baths of Emperor Diocletian appeared, Michele Tramezzino issued a print of the very same building (fig. 3.26).^[87] Engraved by the Netherlandish artist Jacob Bos after drawings by architect and antiquarian Pirro Ligorio, the print depicts an aerial perspective of the complex with its component parts labelled. The viewer therefore looks upon the reconstructed ancient structure from above, easily comprehending its complicated form in a single schematic image rather than experiencing its diverse spaces through horizontal interior views. Only Vincenzo Scamozzi sought to merge these two approaches (fig. 3.27). Entitled Chorographia omnium partium thermarum diocletiani (‘Chorography of all parts of the Baths of Diocletian’) and engraved by Mario Cataro in 1580, it consists of a birds-eye perspective cut away to reveal a transverse section and a plan seemingly measured with cartographic accuracy.^[88] As Scamozzi notes, he combined architectural and optical ways of seeing so the viewer could better visualise the structure’s overall design by synthesising the traditional Vitruvian methods of representation: ichnographia, orthographia and scaenographia.^[89] In this way, he fused Sebastiaan van Noyen’s plan and diascopic views (figs 3.1 and 3.6) to create a single chorographic image that could encapsulate the whole of the structure.^[90]

Compared to these Italian engravings, the Baths of Emperor Diocletian was also significantly more expensive. It also cost at least twice as much as contemporary Dutch illustrated books and sets of prints, which typically sold for a florin or less.^[91] By the end of the century, perhaps due to the publication’s scarcity, the Paduan doctor and bibliophile Gian Vincenzo Pinelli eagerly paid three and a half florins for a set from the cartographer and book trader Abraham Ortelius.^[92] In addition to Pinelli’s library, which contained around ten-thousand volumes, the Baths found its way into the collections of other learned intellectuals such as Joannes Rodenborch, a professor from the University of Wittenberg, and numerous illustrious princely kunstkammern, including those of Ferdinand, Archduke of Tyrol; Augustus, Elector of Saxony; Adolf, Count of Tecklenburg; and Albert V, Duke of Bavaria.^[93] In Albert’s famous Munich collection, the duke placed the prints, mounted on cloth, alongside numerous architectural books, drawings, prints, and maps, and right next to other mirabilia including coral sculptures, animal skulls, and even illustrations of conjoined twins, all of which sought to impart a sense of wonder to the viewer.^[94]

Whether these prints also served as architectural models for new construction is a matter of conjecture, but artists and architects certainly copied and collected them.^[95] A seventeenth-century draftsman, for example, redrew several of the architectural elements onto a sheet of paper now in the Nationalmuseum in Stockholm, and later, another created several finely rendered copies, which came to be collected by Baron Philipp von Stosch in the mid-eighteenth century.^[96] Giovanni Antonio Rusconi, the mid-sixteenth century Venetian architect and illustrator of Vitruvius, owned some of the prints, as did Sir Christopher Wren and Nicodemus Tessin the Younger over a century later, and perhaps even Giorgio Vasari.^[97] A posthumous 1597 inventory of Juan de Herrera’s collection also records a copy bound with other designs for buildings.^[98] It may have indeed been these prints that inspired the Spanish architect to enlist Pedro Perret in 1589 to produce engravings of his vast monastic complex at El Escorial, including four transverse sections and elevations keyed to a pair of plans.^[99] Rather than gazing backwards to the past, these prints project to an increasingly global audience a forward-looking image of the recently completed construction that few had seen with their own eyes.

Herrera’s prints subsequently served as a model for the images of the Temple of Solomon that his student, the Jesuit priest Juan Bautista Villalpando, produced for the second volume of his monumental Ezechielem Explanationes (1604).^[100] These visionary, scroll-like images (fig. 3.28) not only provided compelling divine precedent for El Escorial, but also, according to Villalpando, reconstituted the very architectural images that had been drawn by the hand of God in plan, elevation and perspective, given to Solomon, executed by builders, and described in the prophecies of Ezekiel.^[101] The foldout engravings, therefore, enabled viewers to see like God in sections, which Villalpando described in optical terms as being ‘cut through the cone of vision’. Like the reconstructed views in the Baths of Emperor Diocletian, the engravings of the Temple of Solomon revealed through graphic architectural conventions things that the eye cannot see. Print thereby had the power to provide superhuman ways of looking through buildings, making visible the lost architecture of the past, be it for architectural education, antiquarian erudition, or religious contemplation.

Cock’s prints of the baths continued to be actively collected well into the eighteenth century, but as Johann Joachim Winkelmann lamented, they became increasingly scare over time.^[102] The famous print dealer and collector Pierre-Jean Mariette, in fact, wrote on his copy, now in the Institut de France: ‘few books are as rare as this one. I do not hesitate to add that there are few so curious and so interesting’.^[103] Mariette so valued this work that he had a specially engraved title page made for it. While Palladio’s drawings of the baths became available in the 1730s through a deluxe printed facsimile sponsored by their owner, Richard Boyle, third Earl of Burlington, nothing until the next century came close to approaching the overwhelming scale and effect of Cock’s publication. It was in the nineteenth century that French architects, having won the Prix de Rome, created impressive reconstructions of a variety of ancient Roman complexes as envois to be sent back to Paris for official review.^[104] Similar to the huge drawings for modern structures that they made at the École des Beaux-Arts, these renderings of antiquity—such as those of the Baths of Diocletian by Florimond Boulanger (1842) and Edmond Paulin (1880)—feature expansive elevations and sections, some stretching over three metres (fig. 3.29).^[105] They were also accompanied by complimentary documentary illustrations of the still-standing, heavily ruined structure, which along with related plans make explicit the process of reconstruction that had only been obliquely implied in the earlier 1558 etchings. Yet despite this graphic display of archaeological objectivity, just like Sebastiaan van Noyen’s reconstructions, these later renderings—all finely executed in coloured wash and complete with meticulously delineated wall decoration and sculpture—pull the viewer in with their detail and illusionistic depth; and then push them across to take in the enormity of the structure and the array of unfolding spaces. This horizontal panning impulse, along with the carefully constructed lighting effects and heightened atmospheric perspective, enlivens even the most rigidly symmetrical of examples.

The Baths of Emperor Diocletian—the longest architectural publication produced in early modern Europe, and the only one that was ever mounted on cloth and rolled up as a scroll—represents an important milestone in architectural print culture. Realised through the financial support of a wealthy patron, the technical skill of a prolific publisher, the artistic acumen of his innovative etchers, and the ingenuity of a young architect, this exceptional work—which addressed through text and image a diverse audience of artists, architects, intellectuals, collectors, and rulers—mobilised a new diascopic mode of representation and means of experiencing antiquity. In doing so, it built on over a half-century of antiquarian study, harnessed novel techniques of visualisation, and employed newly developed technologies of documentation. The Baths of Emperor Diocletian also exploited the potential of mechanical reproduction as a medium of preservation and agent of enlivenment, and in its artistic brilliance and technical virtuosity, conferred prestige upon printer and patron alike. While only about a dozen complete sets survive today, this extraordinary Netherlandish work of antiquarian erudition and graphic bravura remains a monumental testament to the power of print and its ability to reconstitute and reanimate the architecture of antiquity.

Michael J. Waters is an assistant professor in the Department of Art History and Archaeology at Columbia University. He earned his PhD from the Institute of Fine Arts, New York University, and was previously the Scott Opler Research Fellow in Architectural History at Worcester College, University of Oxford. He has also held fellowships at the Villa I Tatti, American Academy in Rome, Scuola Normal Superiore di Pisa, and Sir John Soane’s Museum. His work focuses on issues of materiality and objects of architectural transmission, and he has published on range of subjects including spolia in Renaissance Rome, the graphic reconstruction of antiquity, and the creation, use, and dissemination of early modern architectural prints. In 2011, he co-curated the exhibit Variety, Archeology, and Ornament: Renaissance Architectural Prints from Column to Cornice at the University of Virginia Art Museum.