Gothic architecture in miniature: arches, tracery and quatrefoils, and why those shapes read as gothic

A pointed arch on a pair of earrings is doing no structural work whatsoever, and yet everybody reads it instantly. That is a strange thing for a load-bearing solution to a vaulting problem to end up doing. The shapes that signal gothic were all engineering before they were style, and knowing what each one was for is the quickest way to tell a well-drawn gothic object from a vaguely spiky one.

Where it starts

Gothic architecture appears in northern France in the middle of the twelfth century. The usual starting point given is the rebuilt choir of the abbey church of Saint-Denis, just outside Paris, consecrated in 1144 under Abbot Suger, where the pointed arch, the rib vault and large windows come together in one building.

None of the individual elements were new. Pointed arches and ribbed vaults both existed earlier, in Islamic architecture and in Romanesque churches in parts of Europe. What was new was using them together, systematically, with the explicit aim of opening the wall up and getting more glass into it.

The three-part answer everybody learns is pointed arch, rib vault, flying buttress. The flying buttress is the one that does the heavy lifting in the story: it moves the resistance to the vault's outward thrust away from the wall and out into free-standing piers, which is what allows the wall itself to become mostly window.

What the pointed arch is actually for

The popular explanation is that a pointed arch carries thrust more steeply downward than a semicircular one, so it needs less buttressing. That is true and it matters.

The reason that mattered more to the people building these churches is geometric. A semicircular arch has only one possible height for a given span: half the span, always. That is a serious constraint when you are vaulting a rectangular bay, because the arch across the short side and the arch along the long side will rise to different heights, and the vault has to be distorted to reconcile them.

A pointed arch has no such constraint. By moving the two centres of its curves you can give any span any height you like. Suddenly a rectangular bay can be vaulted with every arch rising to the same crown, and bays no longer have to be square. That one freedom is why gothic buildings can be long, narrow and tall, and it is the real reason the shape took over.

Tracery, from plate to bar

Tracery is the stone framework that divides a window. The early form is plate tracery: a solid slab of wall with shapes pierced through it, so that what you see is holes in stone. It looks heavy because it is.

Bar tracery replaces the slab with slender moulded stone bars, assembled like a frame, with the glass filling the gaps between them. The usual credit for its development goes to the builders of Reims Cathedral in the earlier thirteenth century, and once it existed window design became a matter of drawing rather than of carving away.

What followed is a recognisable sequence of fashions. Geometric tracery builds its patterns from circles and parts of circles. Y tracery splits a mullion into a Y. Reticulated tracery repeats one net-like unit over and over. Flowing or curvilinear tracery, in the English Decorated period of the earlier fourteenth century, abandons the circle for continuous S curves. Perpendicular tracery, later in England, runs the mullions straight up to the arch and crosses them with horizontal transoms, producing the grid that English parish churches are full of.

Foils and cusps, and what a quatrefoil is

A foil is a lobe: one arc of a circle bulging inward into an opening. A cusp is the point where two foils meet, sticking inward like a tooth. Those two words cover most small gothic ornament.

Count the lobes and you have the name. Three is a trefoil, four a quatrefoil, five a cinquefoil, more than that a multifoil. A quatrefoil is very often set on the diagonal, so that the four lobes point to the corners and the cusps point up, down, left and right, which is the version you see punched through balustrades and carved into spandrels.

Two more shapes complete the vocabulary. A dagger is a long pointed oval with cusps, and a mouchette is the same idea bent into a curve, like a comma. Both belong to the flowing tracery of the fourteenth century, and both are what fills the awkward spaces between larger circles in a big window. If you can name those four shapes you can read almost any gothic window.

The word was originally an insult

Nobody involved called it gothic. The term comes from Italian Renaissance writers who regarded the architecture of the preceding centuries as barbarous, and who used the name of the Goths to say so. It was a term of abuse for the work of people presumed to have destroyed proper classical building.

The label stuck, lost its sting and eventually became a compliment, which is a useful reminder that these categories are applied afterwards by people with their own argument to make. The builders of Reims and Amiens thought they were building in the modern manner.

The Revival put the shapes on everything

The reason a pointed arch reads as gothic on a small object is the Gothic Revival, not the Middle Ages. From the middle of the eighteenth century, English builders and pattern-book writers began applying the shapes decoratively: Horace Walpole's house at Strawberry Hill, begun around 1749, is the famous early case, and it is gothic applied as surface, with vaulting imitated in papier mache.

In the nineteenth century the revival acquired a moral argument. Augustus Welby Northmore Pugin published Contrasts in 1836 and The True Principles of Pointed or Christian Architecture in 1841, insisting that gothic was not a style you could choose but the only honest way to build. Ruskin's The Stones of Venice followed in the early 1850s. Pugin then designed the interiors and detailing of the new Palace of Westminster with Charles Barry from 1840, which put the vocabulary at the centre of British public life.

The commercial consequence was that the shapes detached completely from structure. Quatrefoils and pointed arches went onto wallpaper, bookbindings, cast iron, furniture, clocks and jewellery, at sizes where they hold nothing up. That detachment is permanent, and it is why a pair of cathedral arch earrings communicates a whole building with no building present.

What makes a small object read as gothic

Proportion first. A gothic arch wants to be clearly taller than it is wide. Draw a pointed arch inside a square and it reads as a tent or a leaf; stretch the same arch to twice its width in height and it reads immediately as a window. If you are judging an object from a photograph, measure the opening: the ratio tells you more than the ornament does.

Then cusps, and the resolution problem. Cusps have to be sharp to read as cusps, and there is a size below which they fill in. A trefoil at ten millimetres usually works. A multifoil at ten millimetres turns into a scalloped circle and the pattern is gone. Fewer, crisper lobes beat more, softer ones at every small size, and that is the single most common failure in cast gothic jewellery.

Openwork is the third thing, and it is what the real architecture is about. Gothic is a structure of lines with light coming through the gaps, so an object that reads the shapes as solid silhouette loses most of the effect. A pierced metal fitting like an iron scroll sconce works because it is line and gap.

The other legitimate approach is to borrow a profile rather than a pattern, which is what a shaped piece of furniture such as a coffin wall shelf does. Mixing the two, so that an outline is gothic and the surface is busy with unrelated detail, is what produces the costume version.

Questions people actually ask

Why are gothic arches pointed?

Partly to direct thrust more steeply downward, but mainly for geometry: a semicircular arch's height is fixed by its span, while a pointed arch can be any height for any span. That let builders vault rectangular bays with all arches rising to the same level.

What is the difference between a trefoil and a quatrefoil?

The number of lobes. A trefoil has three, a quatrefoil has four. The points between the lobes are called cusps. Quatrefoils are frequently set on the diagonal so the lobes face the corners.

What is tracery in a gothic window?

The stone framework dividing the window. Early plate tracery is shapes pierced through a solid slab. Later bar tracery uses slender moulded stone bars, which allowed the elaborate geometric and flowing patterns.