The Textbook of Architecture

Regulae

The Atlas of Rules

672 rules of building, each with the book or building it comes from and a model to turn.

The Derand–Blondel rule for abutments

To find how thick the pier of an arch must be, divide the intrados into three equal parts; draw a line from the springing through the first division, and produce it beyond the springing by its own length. A vertical through the end of that line marks the outer face of the pier.

pier ≈ ¼ span (semicircle) · ≈ 0.23 span (equilateral) · less for a lancet

The pendentive: a sphere cut by a square

To set a round dome on a square bay, imagine a sphere passing through the four corners of the square; cut it by the four vertical planes of the sides and by the horizontal plane of their crowns. The four spherical triangles left in the corners are the pendentives; the circle at their top carries the dome.

sphere radius R = S⁄√2; arches = sphere ∩ side planes (radius S⁄2); ring at h₀ + S⁄2 with radius S⁄2

The line of thrust must stay inside the arch

A masonry arch stands if a line of thrust (the path of the compressive force through it) can be drawn entirely within its thickness; the catenary arch contains its own line of thrust exactly, the semicircle only if it is thick enough.

catenary: thrust line = centre line · semicircle: needs t ⁄ R ≳ 0.11 (Milanković 1907; Heyman)

The architrave a sixth of the light

Make the architrave round a door or window as wide as a sixth part of the opening’s breadth, and dress the openings of the principal floor more richly than those of the storeys above and below, with a frieze and cornice, and on the grandest a pediment.

architrave = ⅙ × width of the light

Acroteria

On the angles of a pediment set acroteria as high as half the tympanum, and on its apex one an eighth higher.

side acroteria = ½ tympanum height; middle = side × 9⁄8

The furniture made with the room

Design the furniture of a principal room with the room: the chairs, settees and stools covered in the stuff of the walls or the bed, the tables and glasses drawn to the architecture of the piers and the chimneypiece, so that the room and its furniture are of one manner and one date.

The formal room: the furniture against the walls

In the formal room, stand the furniture against the walls and leave the middle of the room clear: a pier table (with its glass above) between each pair of windows, the sofa facing the fire, a chair either side of the chimneypiece, the chairs ranged round the walls in a line with the dado, to be brought out when wanted and put back after; and keep each wall symmetrical about its middle, its chimneypiece or its windows.

The Regency room: the furniture in groups

In the room of the Regency and after, bring the furniture out into the room in groups for the occupations of the company: a sofa by the fire with a sofa table before it, a round table in the middle with chairs round it, the pianoforte, a work table, a couch; leave the walls for the pier tables, the cabinets and the bookcases.

The size of a chair

Make a chair about 20 inches wide in front, the seat about 17 inches deep and the seat frame 17 inches high, the whole back about 3 feet 1 inch high; a sofa 6 to 7 feet long, about 30 inches deep and its seat 14 inches high.

chair: 20 in wide × 17 in deep, seat 17 in high, back 3 ft 1 in; sofa: 6–7 ft long × 30 in, seat 14 in

Each room its own furniture

Furnish the dining parlour with solid, substantial mahogany, without trifling ornament, and the drawing room with the lightest and most elegant furniture in the house, in satinwood and painted work, in keeping with its decoration; the library with bookcases and a library table, the bedchamber with what serves sleep and dressing.

The Greek furniture revived

Make the furniture after the antique: the chair as the Greek klismos, its broad back curved to the sitter and its legs swept out like sabres; the couch with one scrolled end; tables on a central pillar and claws or on lion monopodia; and give each piece the plain, broad surfaces and the ornament of the vases and reliefs it is drawn from.

The parterre longer than it is wide

Make the parterre oblong rather than square, since figures somewhat oblong look better on the ground than square ones; later practice made it as broad as the front of the house and about twice as long.

parterre oblong; later practice: width ≈ house front, length ≈ 2 × width

Lawn to the door, clumps on the rises, a belt round the edge

Bring grass up to the walls of the house and keep the cattle off it with a ha-ha; plant trees in clumps on the rising ground and as single specimens on the lawn; and enclose the park with a belt of woodland, with a drive inside it from which the park is seen.

The Crystal Palace grid of 24 feet

Build on a single grid of 24 feet, set by the 8-foot spacing of the roof ridges and the size of the largest pane of glass, so that every column, girder, sash bar and pane is one of a few standard parts that can be made by machine, delivered and bolted together in any number.

pane 49 × 10 in · ridge 8 ft · bay 24 ft · spans 24, 48, 72 ft · 1,848 × 408 ft · tiers 24, 44, 64 ft

The border planted by colour

Arrange a long border in a sequence of colours: at the ends, cool blues, whites, pale yellows and pinks with grey foliage; towards the middle, stronger yellows and oranges rising to the deepest reds at the centre; then back again. Plant in long, thin, overlapping drifts rather than blocks.

Munstead Wood main border: 200 × 14 ft · cool → warm → hot → warm → cool

Ever taller, ever narrower

Within a generation the nave vaults of the French cathedrals rose from about 37 m to 48 m while their spans stayed near 15 m: the ratio of height to width climbed from about 2.3 to over 3, until at Beauvais part of the choir vault fell.

Chartres ≈ 37 m · Reims ≈ 38 m · Amiens ≈ 42 m · Beauvais ≈ 48 m

The Doric corner conflict

A Doric frieze cannot obey all three of its rules at a corner: triglyphs over the column axes, a triglyph turning the corner, and metopes as broad as they are high. One of them must give way.

displacement of the corner triglyph = e − t⁄2 (e = half-depth of the architrave, t = triglyph width)

The door from the height of the room

Divide the height from floor to ceiling into three and a half parts and give two and a half to the opening; make a Doric door five and a half twelfths as wide as it is high (an Ionic one two-fifths), and narrow it slightly at the top.

h = 2½⁄3½ H; Doric w = 5½⁄12 h, Ionic w = h ÷ 2½; top narrowed by ⅓, ¼ or ⅛ of the jamb as h ≤ 16, ≤ 25, ≤ 30 ft

The hall, its screens passage and its two ends

Put the hall at the heart of the house and enter it at one end, by a passage running through the house from front door to back door, screened from the hall. Open the buttery, the pantry and, between them, the way to the kitchen off that passage, at the hall’s lower end; put the family’s parlour, and the great chamber over it, beyond the hall’s upper end, where the high table stands.

The family’s rooms and the servants’, kept apart

Plan the house in two departments, the family’s and the servants’, with their own rooms and passages (and, as the house grows larger, their own stairs), so that neither sees nor hears the other in the ordinary course of the day: the kitchen and its offices to one side or behind, reached by their own corridor, and nothing of the work of the house carried through the family’s rooms.

Every room to its aspect

Give each room the aspect that suits the hours it is used: the drawing room to the south-east, the morning room to the east, the library a little east of south-east, the dining room to the north or north-east, cool and out of the evening sun, and the kitchen and offices to the north; the best aspect of all is south-east, the worst south-west.

The room as an order without its columns

Treat the walls of a room as an order whose columns are left out: the dado, with its base and its rail, stands for the pedestal, the plain wall for the column, and the cornice for the entablature; proportion them as that order is proportioned, so that the cornice of a lofty room is deeper than that of a low one.

height = pedestal (dado) + column (wall) + entablature (cornice); by Vignola’s rule, dado ≈ 4/19 and entablature ≈ 3/19 of the height

The chimneypiece sized and ornamented for its room

Size the opening of the fireplace to the room it warms, small in a closet or bedroom and broad in a hall or saloon, the opening of a small chimney nearly as high as it is wide and of a large one lower in proportion; and make the chimneypiece as rich as the room: an architectural piece with its overmantel in a state room, a plain moulded surround and shelf in a bedroom.

Fireplaces on walls that carry their flues

Set each fireplace against a wall that can carry its flue up through the floors above to the roof: an inner wall that rises through the house or an end wall without windows; put the fireplaces of two rooms back to back on the wall between them, and those of the upper floors over those below, so that the flues gather into a few stacks.

Rooms panelled from floor to cornice

In the panelled room, divide the wainscot as the order divides the wall: low panels below the dado rail, tall panels above it to the cornice, set out evenly between the doors, windows and chimneypiece; in the late seventeenth century frame them with bold bolection mouldings, in the early eighteenth make them raised and fielded.

Floors of each period and room

Pave the hall and the saloon in stone, or in black and white marble laid in squares with a border; floor the living rooms with boards, of oak in the best rooms and deal elsewhere, or with parquet laid in squares; flag the offices with stone; and lay a carpet in the middle of the principal rooms, leaving a margin of floor round it.

The colours and hangings of each period

Finish the walls in the colours of the period: drab, olive and stone colour on the panelling of the early eighteenth century; stone colour and white, with crimson or green damask in the state rooms, under the Palladians; silks and papers with white and gilt woodwork in the Rococo; pale green, pink, lilac and blue under Adam; stripes and strong reds, yellows and greens in the Regency; stone colours with grained woodwork in the Greek Revival.

Windows seen from within: shutters, seats and curtains

Line the reveals of the windows with panelled boxes into which the shutters fold back by day; panel the wall under the sill, and where the sill is low make a seat of it; dress the window with an architrave like the doors’; and hang curtains in the manner of the period, drawn up in festoons in the eighteenth century, in pairs under a pelmet or draped valance in the Regency.

Pier glasses, pictures and lights

Hang a tall glass on each pier between the windows, over a table, with branches for candles beside it; hang the pictures symmetrically about the middle of each wall, the largest over the chimneypiece and in the middle, pairs either side, and in a gallery close together in tiers; light the room from a chandelier in the middle and from the branches on the walls.

The stair’s balusters, handrail and newels by period

Give the stair the joinery of its period: heavy turned balusters on a closed string under a broad handrail in the late seventeenth century; slender turned and twisted balusters, three to a tread, on a cut string in the early eighteenth; plain sticks two to a tread, or wrought iron, under a mahogany handrail later; and in the great houses, steps of stone each built into the wall and resting on the one below, with an iron balustrade.

Roman walls, floors and vaults

Plaster the walls in several coats and paint them: a dark dado below, the middle zone in panels of red, black or yellow divided by painted bands and architecture, a light zone above; lay the floors with mosaic over a bedding of concrete; vault the best rooms; and keep the cornices of rooms used by firelight and lamplight slender and plain, since smoke spoils fine work.

The Doric module

Divide the front of a Doric temple into modules; the column’s thickness is two modules, its height with the capital fourteen, the capital one, the architrave one, and the triglyphs one and a half high and one wide.

M = ½ D; column = 14 M; capital = 1 M; architrave = 1 M; triglyph = 1 × 1½ M; metope = 1½ × 1½ M

The Corinthian capital

The Corinthian capital is as high as the column is thick; its abacus is one seventh of that height, and the rest is divided in three: the lower leaves, the upper leaves, and the stalks from which the volutes spring.

capital = 1 D; abacus = ⅐; leaves : leaves : volutes = 1 : 1 : 1; abacus diagonal = 2 D

A low horizon, one centre of vision, the sun above it

Set the horizon a little below the middle of the picture, about two-fifths of the way up; let the lines of the buildings and the quays run to one point on it near the middle; and put the sun, or its glare, low in the sky over that point, so that the light comes toward the viewer and every building stands against it.

horizon ≈ 0.6 of the height from the top; sun 1°–7° above it

Mauch’s volute: each turn half the one outside it

Draw the Ionic volute seven eye-diameters high and six wide, with the eye four diameters below the top; lay three turns about centres set out in the eye so that each winding is half as wide as the one outside it and the spiral runs into the top of the eye.

height = 7 e, width = 6 e; eye centre 4 e below the top; radii from the eye centre (e = 16 parts): 60, 52, 44, 36, 30, 26, 22, 18, 15, 13, 11, 9 → 8

The golden section

To divide a line in extreme and mean ratio, make the whole stand to the larger part as the larger part to the smaller; the ratio is φ = (1 + √5)/2 ≈ 1.618. Construct the golden rectangle by swinging the line from the midpoint of a square’s side to its far corner.

φ = (1 + √5)/2 ≈ 1.618; φ² = φ + 1; 1/φ = φ − 1 ≈ 0.618

The lower dome pulls apart

Expect a hemispherical dome to be in compression along its meridians everywhere but in tension round its horizontal rings below about 52° from the crown; restrain that lower zone with weight, thickness, rings or chains, or it will crack along the meridians.

thin hemisphere under its own weight: hoop force changes sign at ≈ 51.8° from the crown

The fall of an aqueduct

Lay the channel of an aqueduct with a steady fall of not less than a quarter of an inch in every hundred feet, cover it with a vault against the sun, and carry it through hills in tunnels and across valleys on arches.

minimum fall ≈ 1 : 4,800 (Morgan’s reading); Nîmes aqueduct: ≈ 12.6 m in ≈ 50 km ≈ 1 : 4,000

The Roman theatre: four triangles

Draw the orchestra circle and inscribe in it four equilateral triangles at equal intervals; the side nearest the scene fixes the front of the scaena, a parallel through the centre fixes the front of the stage, and the angles on the auditorium side give the directions of the stairways.

12 vertices at 30°: 7 fix the stairs of the lower cavea, 5 fix the doors and passages of the scene; stage depth = r⁄2

The scene: twice the orchestra

Make the scaena twice as long as the orchestra is wide; raise its podium a twelfth of the orchestra diameter, its lower columns a quarter, their entablature a fifth of the columns; above, a parapet half the podium and columns a quarter shorter than those below.

L = 2D; podium D⁄12; columns D⁄4; entablature ⅕ col.; upper parapet ½ podium; upper columns ¾ lower

Alae, tablinum and fauces from the atrium

Proportion the rooms round the atrium from it: the alae from its length (a third for atria of 30–40 feet, a quarter for 50–60), the tablinum from its width (two-thirds for a 20-foot atrium, half for 30–40 feet, two-fifths for 40–60), and the entrance passage from the tablinum.

alae = L⁄3 … L⁄5; tablinum = ⅔ W (20 ft), ½ W (30–40 ft), ⅖ W (40–60 ft); fauces = ⅔ or ½ tablinum

The peristyle garden

Make the peristyle a third longer across than it is deep, its columns as high as the colonnades are wide, and the spaces between them not less than three nor more than four diameters.

width = 4⁄3 depth; column height = colonnade width; intercolumniation 3–4 D

The forum basilica

Make a basilica between a third and a half as broad as it is long; make each aisle a third of the width of the central space, and the columns as high as the aisles are broad.

W = ⅓ to ½ L; aisle = ⅓ nave; column height = aisle width; upper columns ¼ smaller

The triumphal arch

Pierce a massive rectangular pier with one arch, or with a tall central arch between two lower ones; frame the openings with columns on pedestals carrying an entablature, and crown the whole with a high attic for the dedicatory inscription.

Arch of Titus: 13.5 × 15.4 m, one opening 5.4 × 8.3 m; Arch of Constantine: 25.9 × 21 m, openings 6.5 × 11.5 m and 3.4 × 7.4 m

Each covering has its lowest pitch

Pitch a roof no lower than its covering allows (roughly 45° for thatch, 35° for plain tiles, 20–25° for slate, 15–20° for interlocking tiles, a few degrees for sheet metal) and steeper where snow lies long or rain is heavy.

thatch ≥ 45° · plain tile ≥ 35° · slate ≥ 22½° · pantile ≥ 17½° · metal ≥ 5° · membrane ≈ 1–2°

The jōbō grid: blocks of forty jō

Divide the capital into blocks (machi) forty jō square; gather sixteen blocks into a ward (bō) and the wards into rows (jō); separate the blocks by lanes of four jō and the wards by avenues of eight to twelve, and make Suzaku-ōji, the central avenue, twenty-eight.

machi = 40 jō (c. 120 m) · kōji 4 jō · ōji 8–12 jō · Nijō 17 jō · Suzaku-ōji 28 jō (c. 84 m) · city 1,508 × 1,753 jō

Land in the capital by rank

Grant residential land in whole blocks and fractions of blocks according to rank: several blocks to the highest ministers, one or two to officials of high rank, and to ordinary households a half, a quarter or less, according to their size.

Minister of the Right 4 machi · high ranks 2 · middle ranks 1 · households 1, ½ or ¼ (691); in Heian-kyō, ordinary lots of 1/32 machi (c. 15 × 30 m)

Mountains behind, water before: the geomantic site

Seat the capital in a basin closed by mountains: a guardian mountain behind (north), a lower range on the left (east) as the Azure Dragon and on the right (west) as the White Tiger, a facing hill in front (south); let a stream cross the basin and a great river flow beyond.

Bugaksan (behind) · Naksan (left, Azure Dragon) · Inwangsan (right, White Tiger) · Namsan (in front) · Cheonggyecheon within, the Han River without

Twelve feet between houses

Leave at least twelve feet between a new house and its neighbour; build no balcony lower than fifteen feet from the ground or nearer than ten feet to the house opposite; do not block a neighbour’s view of the sea within a hundred feet; and keep the shops between the columns of the great porticoes small and faced with marble.

gap ≥ 12 ft (≈ 3.7 m) · balcony ≥ 15 ft up, ≥ 10 ft apart · sea view protected within 100 ft

The monastery arranged round the church

Put the church in the centre with its altar to the east; the cloister against its south side, ringed by dormitory, refectory and cellar; the abbot, the school and the guests to the north; the novices, the sick and the gardens to the east; the kitchens, workshops, mills, barns and animals to the south and west; the hospice for the poor by the entrance.

One grid for the whole island

Lay the whole island out in a single rectangular grid regardless of the ground: avenues 100 ft wide running its length, cross streets 60 ft wide across it, and blocks 200 ft deep between them, the houses to be straight-sided and right-angled because such houses are cheapest to build and most convenient to live in.

avenue 100 ft (30 m) · street 60 ft (18 m) · block 200 ft (61 m) deep, 600–900 ft long

The college quadrangle

Build a college as one closed court: ranges of chambers on its sides, entered by staircases from the court, each staircase serving a few sets of rooms on every floor; set the chapel, the hall with its kitchen and buttery, and the library into the ranges, and enter the whole by a single gate under a tower, where the porter keeps it.