Peruzzi Chapel

In Giotto’s Peruzzi Chapel, a palace opens towards the spectator, a funeral procession stops outside a walled city, and an old man rises out of his grave towards Christ. These events occupy walls that face one another across a narrow space in Santa Croce, Florence. The paintings are badly worn, yet their large gestures and projecting buildings still hold together. A hand extended over a bier, a woman carrying a child, or a column standing before a banquet can give a whole scene its direction.

The chapel brings together two saints called John: the Baptist, who announced Christ’s coming, and the Evangelist, associated in medieval tradition with the fourth Gospel and the Apocalypse. Each receives three principal scenes. Their stories move between birth and death, prophecy and fulfilment, the violence of earthly power and the hope of resurrection. Looking across the chapel makes those differences visible. The Baptist’s head passes through Herod’s palace on one wall; opposite, the Evangelist’s body escapes the grave.

The paintings belong to Giotto and his workshop. Their date remains disputed: Santa Croce’s current catalogue labels them about 1310–11, whereas Michael Viktor Schwarz has argued for 1334–36. That substantial disagreement matters when placing the chapel within Giotto’s career. It need not prevent a close encounter with what survives: six carefully selected narratives whose figures, buildings and relationships to the room deserve attention in their own right. ^{[1] [2]}

A painted room beside the high altar

The Peruzzi Chapel stands in Santa Croce’s right transept, second from the high altar, beside the Bardi Chapel. Its patrons were a wealthy local banking family. The neighbouring chapels have distinct programmes: the Bardi paintings tell the life of Francis, while the Peruzzi walls belong to the two Johns. ^[3] The narrow interval between them makes their different narrative choices easy to compare.

Entering beneath the arch, the Baptist’s stories are on the left and the Evangelist’s on the right. On each side a curved upper field sits above two rectangular scenes. The sequence descends from the Annunciation to Zacharias, through the Baptist’s Birth and Naming, to the Feast of Herod; opposite it descends from the Vision on Patmos, through the Raising of Drusiana, to the Evangelist’s Death and Ascension. Painted architectural members, ornamental bands and imitation marble establish an enclosing order around these changing settings. ^[1]

The division into three levels gives each saint’s life a legible downward movement. Yet the facing walls encourage a second movement, across the room. The two upper scenes concern revelations granted to solitary recipients. The middle pictures place miraculous life within households and communities. At the lowest level, elaborate interiors frame two radically different endings. These connections emerge from the selection and arrangement; they do not require the scenes to be exact visual doubles.

Above them, Evangelist symbols occupy the vault and eight prophets appear in the entrance arch. A fragment of the Mystic Lamb remains on the rear wall. ^[1] The decoration therefore extends beyond the six famous pictures. Sacred history, prophecy and the altar’s liturgical setting surround the narratives, giving the little room a larger theological horizon.

The Peruzzi family and the chapel’s purpose

A document discussed by Schwarz takes the chapel’s history back before the paintings. On 21 November 1292, Donato di Arnaldo Peruzzi made a conditional bequest of 200 lire towards building a chapel if the Florentine Franciscans enlarged or rebuilt their church within ten years of his death. His brothers were to administer the provision. This is evidence for the foundation’s beginnings, rather than a dated commission for Giotto’s murals. One brother named among the witnesses was Giotto Peruzzi, a member of the banking family who must be distinguished from the painter. ^[23]

Founding and decorating the chapel involved successive decisions. A family could establish an enduring place within a church, then equip it over time with paintings, glass and an altarpiece. The saints’ stories would enter a setting already bound to family memory, prayer and commemoration. Schwarz reads the Evangelist’s three scenes especially in relation to these interests: visions of the world to come, a woman raised from death, and the saint’s own exceptional passage into heaven offered powerful material for a funerary chapel. ^[23]

Identifying one individual as the certain commissioner of the paintings is harder. Schwarz questions the traditional selection of Giovanni di Riniero Peruzzi, which rests on a much later family history without an identified supporting source. He instead considers responsibility across the family and its senior members. His reconstruction usefully keeps the undertaking collective, although it does not supply a surviving contract naming who chose every subject or paid every instalment. ^[23]

Charity also belongs to the chapel’s history. Schwarz discusses records of Peruzzi provision for feeding the poor at Santa Croce on the Evangelist’s feast in 1335–38. These practices connect family remembrance with a public religious obligation. They do not prove that the paintings were completed for the first recorded distribution, or that every early distribution took place inside the chapel. The distinction matters: an act of charity can illuminate the setting without becoming a missing painting contract. ^[24]

Why two Johns?

The dedication allows two different kinds of holy witness to share one room. The Baptist’s chosen scenes concentrate on his promised birth, the confirmation of his name, and the circumstances of his death. The Evangelist’s begin with visionary exile, then show his power to restore life and his reception into heaven. The resulting programme is highly selective. Neither wall attempts a complete biography.

For a Florentine audience, the Baptist also carried a civic association. He was the city’s patron, honoured at its Baptistery. Schwarz relates the Peruzzi narratives to that much larger field of imagery, including the Baptistery mosaics and Andrea Pisano’s bronze door. Within Santa Croce, he also considers Franciscan associations: the tradition that Francis had first been named John, and the understanding of his preaching through the Baptist’s example. These are possible interpretive connections within the institution, rather than instructions preserved from the chapel’s patrons. ^[25]

The surviving Lamb helps bind the saints together. In the Gospel of John, the Baptist identifies Christ as the Lamb of God; the Lamb is also central to the Apocalypse. Schwarz draws attention to the way that this shared image joins the two lives and connects them to the altar, where the Eucharist was celebrated. ^[23] The relationship is especially apt in a chapel concerned with death and salvation: individual stories open onto the sacrifice and promised life that give them their religious meaning.

The pairing remains effective at a simpler visual level. One wall ends in a court where a holy body is dismembered and its head displayed. The other ends in a church where a holy body rises beyond ordinary mortality. Between these endings lie two communities gathered around newly manifest life. The room lets viewers make such comparisons through the act of turning.

The Annunciation to Zacharias

The Baptist’s story begins high on the left wall. A columned sanctuary occupies the centre of the lunette, its triangular pediment and circular ornament fitting beneath the chapel’s arch. Inside, Zacharias confronts an angel across the altar. Groups to either side make the encounter part of a larger religious gathering, while the building rising behind the sanctuary adds depth on the right.

Luke’s Gospel provides the narrative. Zacharias, an elderly priest whose wife Elizabeth is also advanced in years, receives Gabriel’s announcement that they will have a son named John. He doubts the promise and loses the power of speech until its fulfilment. Outside, the people await him and recognise from his signs that he has seen a vision. ^[26]

Giotto gives the exchange a definite place without enclosing it beyond sight. The slender supports identify the sanctuary and leave its interior accessible to the spectator. Zacharias’s raised hand and the angel’s facing gesture carry the encounter across the altar. The architecture holds them apart while making their relationship unmistakable. Its measured uprights steady a moment whose consequences will unfold in the scene below.

There is also a striking difference between the building’s upper grandeur and the gathering along its base. The pediment, roof and adjoining block stretch into the lunette, whereas the people form a lower, closely spaced company. Their heads and hands create smaller exchanges around the principal meeting. At the left, a harp adds an unexpectedly specific object to the temple setting. Its curved outline contrasts with the straight supports and courses of masonry.

The worn surface now makes some figures almost transparent against the blue field. Even so, the division between sanctuary, company and rear building survives clearly. Rather than relying on tiny facial details, the scene can still be read through positions: the two central presences, the altar between them, and the witnesses distributed outside their immediate exchange. The promise begins in a public religious setting, although its fulfilment will take place within a household.

The Birth and Naming of the Baptist

The middle scene opens a house in section. At the right, Elizabeth lies in a bed attended by women; at the left, Zacharias sits writing as an attendant presents the infant. A vertical architectural division separates the two spaces, while their upper walls and projecting roofs bind them into one substantial dwelling. The picture makes successive events available in a single view.

In Luke, the naming occurs when relatives and neighbours gather for the child’s circumcision on the eighth day. Elizabeth insists upon John rather than his father’s name. Asked to confirm the choice, Zacharias writes the name, and his speech returns. ^[26] The painting joins childbirth to this decisive recognition. Its subject includes the establishment of the child’s identity, as well as the fact of his arrival.

Zacharias’s seated, forward-bending body makes writing a physical act. The tablet rests close to his lap; his attention is directed downwards while the people bringing the child approach from the centre. The infant’s small size sharpens the scale of the adults around him. Their large mantles, bent shoulders and overlapping bodies give the foreground a weight that the delicate child interrupts.

At the right, the bed extends across the room like a broad platform. A long reddish chest with visible fittings stands before it. The combination of chest, bedding, attendants and upper storey makes the house feel furnished and inhabited. These objects also establish the distance between the bed and the spectator. We look past something solid and useful into the space of care surrounding Elizabeth.

The direction of the story differs from a simple left-to-right reading. The birth takes place on the right, while its later consequence occupies the left. Architecture allows the moments to coexist without requiring the eye to confuse them. One can first recognise the bed, then follow the child into the adjacent gathering, or begin with the concentrated act of writing and look back towards its cause.

Schwarz reads the infant’s extended arm as an anticipation of his preaching, an unusually early declaration of the Baptist’s vocation. He connects it with the Franciscan associations of the saint’s name. ^[25] The gesture is visible; the full symbolic argument remains an interpretation. Either way, the child is already active within the composition. Held by an adult, he reaches into the exchange that will give his life its public name.

The Feast of Herod

The lowest Baptist scene brings a change of atmosphere. A richly articulated palace occupies almost the entire field. Its banquet hall stands open behind a column, an adjoining chamber is visible through an arch at the right, and a tower rises at the left. Small figures crown the roof. Within this elaborate setting, a musician plays, Salome performs, a soldier presents the Baptist’s head, and the head appears again as Salome offers it to Herodias.

Mark describes Herod’s imprisonment of John, the birthday feast, the daughter’s dance, her request prompted by her mother, and the execution ordered by the ruler. The soldier gives the head to the girl, who passes it to her mother. ^[27] Giotto’s arrangement brings several stages together. The actual act of beheading is absent from the principal action; its result enters the feast and then moves into the neighbouring room.

The same head therefore belongs to different moments within a shared architecture. In front of the banquet table it interrupts the company’s celebration. At the right, it becomes an offering placed before the seated Herodias. The arch does useful narrative work: it lets the second transaction remain visible while marking a different place. The palace is at once a convincing building and a means of connecting events that could not all occur simultaneously.

Salome’s dancing figure does relatively little with her feet. Her lifted hands and the space around them give the performance its delicate emphasis. Against that refinement, the dish bearing the head is brutally explicit. Both dance and murder take place within the ordered world of the court, among fabrics, a laid table and architectural ornaments. Their proximity is more unsettling than a separate execution scene would be.

The musician stands at the left edge of the hall, bow and instrument set across his body. His open mouth gives the performance a suggestion of sound as well as movement. That occupied figure helps distinguish the feast from the quieter household above. Here bodies entertain, watch, eat, carry and command. The picture distributes the consequences of power across a whole company.

Schwarz’s close reading goes further, interpreting particular guests, servants and the musician as commentators on the event. He also compares Herod’s hand above a bowl with Pilate’s gesture of disclaimed responsibility. These readings concern culpability and the difference between apparent regret and hypocrisy. They draw on a Tuscan John legend as well as Mark; the detour in which the head is brought before Herod is one important distinction from the Gospel’s sequence. ^[28]

The picture supports sustained attention to those gestures without allowing certainty about every person’s private thought. A guest’s lifted hand, a turned head or two figures leaning towards one another can suggest interruption, unease or discussion. Their ambiguity keeps the court from becoming a collection of simple emotional labels. The Baptist himself has been removed from conversation, yet the severed head makes his presence impossible to ignore.

At the far left, the tower’s dark grated opening raises a further question. Schwarz notes that copies of the painting show the Baptist’s decapitated body there, and considers the structure a possible prison. ^[29] That evidence belongs to the history of the image. The body should not be described as clearly visible in the worn painting today. The legible transfer of the head already establishes what has happened beyond the banquet’s open stage.

The Vision on Patmos

Across the chapel, the Evangelist’s cycle begins with a different kind of withdrawal. John sits on a rocky island surrounded by patterned water. The land is broad enough to hold him, yet small enough for the sea to enclose it visibly. Above, visionary figures and a dragon occupy the blue field beneath the arch. The image replaces the Baptist’s substantial temple with an exposed natural setting.

The opening chapter of Revelation places John on Patmos and describes the command to record what he sees. The Peruzzi programme follows the medieval identification of this visionary John with the Evangelist. ^[30] Its upper scene gathers an apocalyptic world around the seated saint rather than presenting the writing of a Gospel inside a study.

John’s pose is remarkably compact. One hand supports his head; the mantle gathers around his bent body. He occupies the middle of the island while the visions spread above and around him. The physical concentration of the saint provides a quiet centre against the animated creatures and appearances. Isolation becomes a visible condition of revelation.

The sea is important to that effect. Its repeated curling lines wrap around the irregular shore and separate the island from the lower edges of the painting. Seen from above, the land can be grasped as a whole. Yet John remains a large, weighty figure rather than a tiny inhabitant lost in a map. The image combines a surveying view of the setting with an intimate view of its principal occupant.

A dragon stretches through the upper blue, while another visionary figure reclines at the right. Their positions belong to a different order from the shoreline below. Giotto does not need a single continuous terrain to make the encounter intelligible. John’s stillness, the enclosing water and the charged upper space establish the difference between bodily location and visionary experience. The chapel’s curving arch gathers these otherwise dispersed presences into one field.

The Raising of Drusiana

The middle Evangelist scene returns to a populated world. John stands at the left, extending his right arm towards Drusiana, who has risen on her bier. Figures kneel near him; the funeral company gathers on the right. Behind them stretches a city wall, with a towered gate at one side and a large domed church at the other. The architecture continues across the full scene and makes the miracle feel like an event occurring before a city.

This is a story from the Evangelist’s later legend. In the Golden Legend, John returns from exile to Ephesus and encounters the funeral of Drusiana, a devoted follower who had longed to see him again. He orders the bier set down and the body unbound, then calls upon Christ to raise her. She returns to life and goes home to prepare food for him. ^[31] The medieval account supplies the story’s religious framework; it is distinct from the Gospel narratives of Jesus raising the dead.

The painting chooses the moment of restored encounter. Drusiana’s upright torso and lifted hands answer John’s extended arm across a narrow interval. Around them the company forms two uneven masses. The kneeling figures bring the saint’s gesture close to the foreground, while those behind the bier form a standing screen of heads and draped bodies. The space separating John and Drusiana becomes the scene’s most active passage.

It is also where the city wall changes direction. The bend behind the miracle interrupts a long horizontal run and brings architectural movement into relation with the figures’ exchange. At the left, the gate gives John’s arrival a setting. At the right, the church rises above the mourners. Buildings help organise the action without being reduced to small props placed immediately behind individual people.

The church’s domes, rounded openings, projecting apse and bands of ornament make it exceptionally specific. Its upper parts appear over the wall, while the crowd conceals much of its lower structure. The result resembles a view into a larger city whose buildings continue beyond the immediate ceremony. The wide blue sky between gate and church keeps the architecture from closing into a solid backdrop.

Schwarz argues that this setting draws on the church and topography of medieval Ephesus, adapting features familiar from Italian architecture. He discusses the resemblance to the Santo in Padua but resists treating that building as a sufficient explanation of the whole. His proposal is an interpretation of the painted architecture, not proof that Giotto travelled to Ephesus. He considers information reaching Florence through Peruzzi commercial contacts more plausible than an otherwise undocumented personal journey; Franciscan connections offer another possibility. ^[32]

The picture remains compelling without settling the source of every dome. Its panorama gives the sacred event a substantial urban world. There is enough specificity to invite recognition, and enough continuity to suggest that life carries on beyond the painted frame. Drusiana’s return to her household, described in the legend, can be imagined within such a city. The miracle concerns both a body restored to life and a person restored to a community.

The Death and Ascension of the Evangelist

Below Drusiana, another church opens before us. Columns, upper walls and exposed roofless spaces arrange the witnesses around a central opening. John rises diagonally towards Christ, his hands lifted to meet those extending down to him. At the left, men bend towards the grave; at the right, a taller company looks towards the event. A crumpled red garment near the opening makes a low, earthly counterweight to the ascending body.

The Golden Legend describes Christ announcing John’s approaching death. After celebrating Mass, the saint enters a grave prepared before the altar and prays. A brilliant light prevents the people from seeing him, and afterwards the grave contains manna. The text reports the belief that he was carried bodily into heaven while reserving certainty to God. ^[31] Giotto gives that belief a direct pictorial form: the saint rises bodily towards a heavenly welcome.

The building is designed around the act of looking. Its columns make the interior accessible; its upper walls step aside around the route of ascent. An uninterrupted diagonal joins the grave, John and Christ. The architecture establishes weight and enclosure, then allows the saint’s body to pass through them. Compared with the broad city behind Drusiana, this is a closely organised interior built for a particular revelation.

The witnesses do not all look in the same direction. Bent bodies at the left attend to the grave, bringing absence into the story. Upright figures at the right face the ascending saint. Their different orientations divide the event into things that can be discovered and things that can be seen happening. The spectator has a more comprehensive view, able to connect the opening below with the reception above.

The heavenly company is now very faint in ordinary light. This loss can make the scene appear dominated by an isolated rising figure, although its action depends on a meeting. Modern ultraviolet photography has helped clarify the receiving group, including Christ and the apostles. ^[33] The visible remains still preserve the essential link of raised and extended arms. Across from the court where hands pass a severed head, these hands draw a whole body upwards.

Architecture and the spectator

The six settings ask for different kinds of attention. Zacharias’s sanctuary presents a central exchange; the birth scene opens adjoining rooms; Herod’s palace connects successive acts; Patmos encloses a solitary figure in water; Drusiana’s city spreads behind a public miracle; the final church arranges itself around a passage into heaven. Buildings and landscape give each story a different relationship with the spectator.

Their relationship with the real room is equally important. A reproduction normally places a rectangular scene directly before the viewer. In the chapel, the facing walls stand too close together for that detached view to explain the whole experience. From the entrance, the pictures are approached obliquely. Their architectural edges, projecting roofs and columns can therefore answer the depth of the chapel itself.

Schwarz examines this effect particularly on the Baptist wall. Seen from outside the chapel, the corner column of Herod’s hall can appear to stand towards the spectator, while the building beside Zacharias’s sanctuary leads backwards with the real space. In the Birth and Naming, the projecting wall beside the seated father can seem to join the chapel wall. These are arguments about a picture’s adjustment to a particular viewing position. ^[29] They need not be turned into a claim that every painted orthogonal belongs to one mathematically unified perspective system.

The shifting spaces also govern access. We are shown interiors whose occupants can be seen without the obstacles that a real façade would impose. Yet columns, chests, tables and standing bodies preserve a sense of things lying between us and the action. The pictures offer entry while retaining intervals and thresholds. Their drama depends partly on seeing across those intervals: an altar, the distance from father to child, the width between John’s blessing hand and Drusiana’s answering palms.

Paint, damage and rediscovery

The present surface requires patience. Some passages preserve strongly modelled folds and substantial colour, while nearby faces have become pale or incomplete. The unevenness can make a single figure seem less solid than its outline promises. Schwarz’s discussion of surviving drapery and furnishings stresses how much material richness has been lost. His account is a reconstruction from remnants, not a description of an intact decorative surface. ^[29]

The chapel’s technique helps explain its vulnerability. The narrative scenes were painted on dry plaster. Cecilia Frosinini’s technical account also identifies fresco work in parts of the vault, preparatory areas and imitation marble, distinguishing these from the stories themselves. ^[33] Calling the whole ensemble simply a cycle of frescoes can obscure this variation. Pigment applied with a binding medium to a dry surface has a different relationship with the wall from colour incorporated into fresh lime plaster.

The condition also reflects later intervention. Eighteenth-century whitewashing concealed the paintings. Antonio Marini’s work in 1841–48 and the Pezzati campaign of 1861–63 exposed and repainted them, with cleaning causing irreversible damage. Leonetto Tintori removed later additions in 1958. The Opificio delle Pietre Dure worked on the paintings in 1983–85 and undertook diagnostics in 2009–10. ^[3] This history explains why rediscovery and loss can belong to the same episode: uncovering a medieval painting can damage the very surface being recovered.

Nineteenth-century repainting also changed how the pictures were understood. Schwarz compares the musician’s head before and after removal of overpaint, arguing that the added expression softened the more difficult original conception. ^[29] The issue extends beyond whether a restored face looked attractive. An altered glance or mouth can change a figure’s role in the story, and therefore the moral relationships among the people at the feast.

Frosinini’s report describes ultraviolet fluorescence photography revealing faint modelling, drapery and figures. It records a complete photographic campaign in November 2012. She leaves the unusually strong fluorescence’s cause unresolved, considering interactions among original materials and later treatments. ^[33] These images expand the evidence available for understanding Giotto’s forms. They do not mean that lost colour has been physically returned to the walls, or that the paintings now appear in ordinary light as they did when new.

The distinction encourages a double attention. The surviving paintings remain the works encountered in the chapel, with their interruptions and areas of silence. Technical photographs help establish that some apparent flatness belongs to damage rather than design. The solid shoulders, hanging fabric and carefully furnished rooms were originally more fully articulated. Their present incompleteness should neither erase that ambition nor invite an imaginary restoration of every missing detail.

A disputed place in Giotto’s career

The dating problem is unusually large. Santa Croce’s catalogue gives about 1310–11, while its discussion acknowledges competing placements before and after the Bardi murals. ^[1] Schwarz’s much later proposal, 1334–36, depends especially on relationships with Andrea Pisano’s Baptist narratives for the Florentine Baptistery. The bronze door’s documented production provides a chronological framework; the direction in which the two artists exchanged ideas remains contested. ^[2]

Shared poses alone cannot settle the matter. Schwarz notes that the seated, writing Zacharias has an earlier precedent in the Baptistery mosaics, and that the related musicians do not establish which artist supplied the other’s model. His stronger argument concerns narrative construction: he considers Giotto’s compressed Feast of Herod dependent upon the fuller sequence Andrea had developed. Accepting that argument moves the murals into Giotto’s final years; rejecting its direction leaves other chronologies open. ^[2]

The charity records do not independently close the gap. Schwarz conditionally narrows his proposal to 1334–35 if the distributions began in 1335 and already belonged to the chapel. Those assumptions are not secured merely by the existence of the accounts. ^[24] The foundation bequest of 1292, meanwhile, dates an intention to build, not the wall paintings. The family’s records and the paintings’ visual relationships cannot supply the same kind of date.

For the viewer, the unresolved chronology changes the larger career narrative rather than the identity of the scenes. Under an early dating, their spatial complexity follows relatively soon after Padua; under Schwarz’s reconstruction, it becomes part of a late phase of renewed experimentation and exchange with other painters. Schwarz’s larger account allows for stylistic variety within a late period: changed demands and exchange with Sienese painters could produce different solutions rather than a uniform final manner. ^[34] That interpretation challenges a simple progression from youthful discovery to settled old age. Its explanatory force remains connected to his disputed chronology. What the chapel itself establishes is a sustained willingness to change the scale of buildings, the handling of time and the relation between a painted scene and its spectator.

The chapel’s changing ensemble

The room has also changed through the movement of its furnishings. Santa Croce associates its original altarpiece with the painting now in the North Carolina Museum of Art, Raleigh. The museum presents the Peruzzi destination more cautiously, as a proposal supported by the saints depicted. The panel gathers Christ, Mary, the two Johns and Francis beneath pointed arches. ^[35] Its association is persuasive without being equivalent to a surviving commission document. The Peruzzi Altarpiece deserves to be considered alongside the murals as a distinct object with its own history.

The Raleigh Peruzzi Altarpiece, proposed as the chapel’s original altarpiece.

Today the replacement panel is by an anonymous painter close to Bernardo Daddi, and the window came from the Giugni Chapel and is attributed to Pacino di Bonaguida. The monument to Vincenzo Peruzzi on the right wall is nineteenth-century work by Odoardo Fantachiotti. ^[3] These furnishings belong to different moments in the room’s history. They should not all be mentally assembled into the setting Giotto knew.

The painted borders, too, deserve a glance beyond their framing function. Santa Croce cautiously suggests that small heads within the ornamental bands may represent members of the Peruzzi family. ^[1] The proposal leaves their identities open. What can be seen is the insertion of particular faces into an ordered decorative scheme, on a scale different from the saints’ monumental narratives.

Returning to the facing walls restores the chapel’s strongest unity. A child reaches towards a father who writes his name; Drusiana raises her hands towards the man who calls her back to life. Herod’s hall exposes the consequences of a ruler’s commands; the opposite church opens around an ascent that earthly architecture cannot contain. Despite the losses, Giotto’s painted room still makes these relationships legible through bodies, objects, openings and distances. Its stories gather their force across the small space that separates them.