The geometry of 18th C. furniture design explored by Steve Brown and Will Neptune

 Steve Brown and Will Neptune, are cabinet markers who also teach. 
They wrote  Classic Proportion in Eighteenth Century Furniture Design.*  It is a fascinating exploration of the use of geometry in the design of 18th c. cabinet makers. The illustrations are beautiful.

I first read the article around 2020. Unfortunately, I knew very little about 18th C. cabinetmaking. Visually, the circles overwhelmed me. I just didn't get it. I put the article aside, hoping that maybe later I would understand. 

Last winter  I tried again. The article references James Gibbs' Rules for Drawing the Several Parts of Architecture**, first published in 1722. a book I hadn't read.  I bought a copy. It was a poor reproduction, difficult to read. Then I found a clean, legible copy online. I could enlarge the words and images to easily study them.  This drawing is part of Plate XXXVII.

Gibbs wrote clear and thorough explanations. 

 As I learned, I remembered the tic marks and notations  running up the borders of other pattern books: Wm Pain, A. Benjamin, Owen Biddle.  Now those segmented lines made sense. They are units of measure, a length which determines the other lengths in a specific design, a dimension that can be set with dividers, a compass. Palladio used m for 'module', Gibbs used dia for 'diameter'. Both are names for the same thing, a dimension, a building unit.    

I found that Gibbs' rules for frontispieces were used on this side of the Atlantic. ***  

 

Here is a partial view of Pain's Frontispiece in the Ionic Order, c. 1774.***

The dimensions of the door are noted in diameters as well as in feet and inches. 

 

Asher Benjamin's engraving of a Doric entrance, 1797, lays out the dimensions along the left side, but simply lists them along the bottom. He writes that "the height of the column is 10 parts, one of which is the diameter of the column..."  He uses one diameter for the sub-plinth, two for the entablature.

Yes, Asher Benjamin's first book has poor quality prints.***  

  

 

 

A partial view of an Owen Biddle frontispiece showing  a scale at the bottom, the door width divided into 9 parts, and the height shown as 10 diameters. ***

Finally, I could begin to read 'Classical Proportions'. To encourage you to read the essay, here are 2 diagrams from the article. 

Figure 12, Line drawing of a Chapin high chest of drawers with a modular overlay.

 

 

 

 

 

 

Figure 49 is a detail of the foot and ankle of a leg.

 

 

 

 

 

Figure 50 shows the diagrams for the geometry used to lay out the sizes and curves of the foot, showing, to quote the authors,"the stages of development." As this is quite similar to my understanding of how designs develop I thoroughly enjoyed thinking through the details. 

 

  

  

 

  

  

 

 

 

 

 

 *Classic Proportion in Eighteenth Century Furniture Design is available on line. https://chipstone.org/article.php/787/American-Furniture-2017/Classical-Proportioning-in Eighteenth Century Furniture Design.  

** James Gibbs, Rules for Drawing the Several Parts of Architecture, London, 1722.

*** William Pain, The Practical Builder, published in London, 1774. partial view of PlateXVI.

      Asher Benjamin, The Country Builder's Assistant, published in Greenfield, MA, 1797. partial view of Plate X.

     Owen Biddle, Biddle's Young Carpenter's Assistant, Philadelphia and New York, 1805, partial view of Plate 17. 

My blog posts which explore the use of Gibbs' Rules in the States.  

https://www.jgrarchitect.com/2024/12/james-gibbs-rules-for-drawing-several.html

https://www.jgrarchitect.com/2025/01/james-gibbs-and-rockingham-meeting-house.html 

 

James Gibbs and the Rockingham Meeting House

This blog post assumes you, the reader, are familiar with James Gibbs' architecture. If you need an introduction or a review, check the end of this blog. You will see links to what I wrote about him and his work. See also Wikipedia.

 

Did anyone in the States study James Gibbs' books?

Yes. Gibbs' On Architecture*, published in 1723, was imported to the Colonies. We know the steeple designs were studied and copied**. 

His book, RULES for DRAWING the several PARTS of ARCHITECTURE*, was also in the Colonies. 

Both books were in bookstores and private libraries. 

 

Were the rules Gibbs drew standard knowledge? Or was he simply the first to write them down? 

Did builders follow his layout instructions?  

I don't know yet. I'm studying historic doors, leaving surrounds and architraves for later research.

 

HABS has measured drawings of the Rockingham Meetinghouse in Rockingham, Vermont. It was  built from 1787 to 1797.  The Master Builder was John Fuller. The Master Joiner - who would have built the doors - is not recorded. He could have been John Fuller.

I know the Meetinghouse well. I've studied it, given tours, taught and written about the geometry of its construction as well as how the door paneling fits by the Rule of Thirds.**

 

The main door

 

 

 

 

 

 

 

 

 The HABS drawing of this door

 

 

 

 

 

 

 

 

That drawing with the dimensions inked out in order to make James Gibbs' geometry easier to read.

2 squares.

The width divided into 6 parts, 3 noted. Then one part (1/6 the width of the door) determining the width of the surround.  

I have used the arcs and lines that Gibbs used for his door layouts. The radius of the arc is the width and height of the square. This is a builder's 'shorthand'.

This layout matches the door on the left in Gibbs' drawing shown above.

 

A line can be divided into 6 parts using the Rule of Thirds. See Part II of my post on James Gibbs and the Rockingham Meetinghouse. The link is at the bottom of this post.**

 

 The door for the right stair wing at the Rockingham Meetinghouse

 

 

 

 

 

 

 

 

 

 

The HABS drawing for the right stair wing door

 

 

 

 

 

 

 

 

 The geometry: 

2 squares and 1/6 added to the height ( the red rectangle at the top)

This geometry matches the layout of the middle door in Gibbs' drawing of 3 doors shown above.

 

 

 

 

Then, I tried using the 1/6 part of the door width  as a radius.
I placed 3 circles on the width, the red line across the middle of the door. The dimension of the circles is the radius x 2: simple geometry.

 Beginning at the bottom of the door I stepped off 8 semi-circles up  the right hand side. They are the same width as those across the width of the door. Those semi-circles lay out the height of the door surround, the beginning of the architrave and its height.

Finally, I saw that the width of the pilasters on each side of the door was the same width as the circles. See the circle on the left pilaster.

The HABS drawings are small. The dimensions were made to record the building, not to record the geometry. Either the recorder or I may have missed nuance. This year, when the Meeting House is accessible, I will measure the doors to see how close what I've drawn is to the actual doors.

 

*James Gibbs,  On Architecture, 1728, London, Dover Press reprint

                         Rules for Drawing the several Parts of Architecture, 1753 edition through the University of Notre Dame  https://www3.nd.edu › Gibbs-Park-folio-18

**   https://www.jgrarchitect.com/2021/12/james-gibbs-book-of-architecture.html

       http://www.jgrarchitect.com/2022/02/james-gibbs-steeples.html

       https://www.jgrarchitect.com/2014/04/rockingham-meetiinghouse-rockingham-vt.html 

      https://www.jgrarchitect.com/2024/05/how-to-layout-pediment-350-years-of.html

James Gibbs' Rules for Drawing the several Parts of Architecture

My previous post looked at Palladio Londinensis' instructions for the use of geometry to design of entrances.* I found that essential information necessary to the layouts was left out/ not understood/missing.  Given that background, reading and writing about this book by James Gibbs has been a pleasure.

 

RULES for DRAWING the several PARTS of ARCHITECTURE

IN A More exact and easy manner that has been heretofore practiced by which all FRACTIONS, in dividing the principal MEMBERS and their Parts, are avoided.

 
By JAMES GIBBS

The Third Edition, 

London      1753**

This is a small book, 28 pages of text, 64 engravings. Gibbs is simplifying the design of columns. He discusses the complexity of dividing a module (the diameter of given circle) into minutes and seconds; that it's difficult to "divide the small parts with a compasses" and may "occasion mistakes".

He starts, "Of Columns and their Measures". The heights of columns are listed:  "The Tuscan - 7 diameters. The Doric - 8 Diameters. The Ionic - 9 diameters. The Corinthian - 10 diameters. The Roman or Composite - 10 Diameters." Next he discusses Entablatures, then his 64 Plates.

PART I

I am curious about how did masons and carpenters working on ordinary vernacular buildings use Practical Geometry. Can Gibbs' engravings tell me about vernacular design c.1730-50? 

Here are Gibbs' notes on 6 doors.

 

Plate XXVII shows 3 door frames: Tuscan, Dorick, and Ionick.

Each door has a segmented line on the left side. The divisions start at the top of the base of the columns. The Tuscan and Dorick lines both have 5 sections, one of which is the entablature's height.

The Ionick door has 6 sections, one of which is the entablature.

 

Those sections are the modules for all the parts of the door. The module is a length, a diameter of a circle drawn by a compass. So how does builder choose how big to make it? Where does he begin? 

Gibbs writes, "First find the Diameter of the Column, give 6 Diameters from middle to middle of the Columns..." 

From that diameter comes the sizes: the spacing of the columns, the width and height of the door opening. The door frame is a 'semidiameter', half a diameter, a radius.

 

Gibb's drawings are spare, clean.  His explanation, The Ionick Door, Plate XXXVII, second paragraph, for "The Geometric Rule to find the height of the Pediment..."  is easy to follow. ***

 

Vernacular buildings in the Colonies had doors with similar entablatures. Do the entrances for the Rockingham, VT, Meetinghouse follow Gibbs' instructions?  I will check.

 

 

 

PART II 

Gibbs' Plate XLII,  'Three Doors with Archtraves'. 

Gibbs focuses on the architraves. I am looking at the doors. I want to know if our American builders use these rules to layout doors.****

The doors begin with a square whose length is the width of the door. The diameter of the square is divided into 6 parts. One part is the width of the frame, the Architrave, which today we would specify as the molding or trim. The middle door is taller: it adds one more part (1/6) to the width and height of its trim. The diagonal of both squares "gives the bigness of the pilaster upon which the Scroll is fixed."

The geometry for dividing a diameter - or any line - into 6 equal parts

Using your line as the length of the sides, draw a square. 1) Add the diagonals . 2) Add the center lines. 3) Add the 4 lines from corner to opposite center point. Note the points where the  lines intersect.  4) Connect those points with lines.

You have divided the square into 3 long rectangles, and your line into 3 equal parts. See '1/3,1/3/1/3' above the square.

The distance between the center line of the square and the closest vertical line is 1/6 of your line . See "1/6" below the square, lower right. 

                                                                                                                  

 

*  https://www.jgrarchitect.com/2024/12/palladio-londiensis-frontispieces-c1755.html

**I am reading this through the University of Notre Dame  https://www3.nd.edu › Gibbs-Park-folio-18 

The first edition was published in 1732. It was available for purchase in the Colonies. I am always interested to see what words and phrases are capitalize in books printed in this era. 

***For  more information about pediments see my posts about Vignola's Rule for Pediments 

**** Today, a builder has a catalogue of doors to choose from. The doors may look different, but their widths and height are  similar: exterior doors are 3' x 6'8", 3'x7'. Other sizes must be special ordered or custom-made.  Before the Industrial Revolution there was no such uniformity.

 

How to Layout a Pediment: 350 years of instructions

A short history of classical pediments in the Western world,  c. 1540 to c.1903. 

Vignola's Rule was first laid out by Giacomo (Jacopo) Barozzi da Vignola in his Cannon, published in 1562.

This image was  published in 1903 in William Ware's The American Vignola.* 

 

Was it Vignola's  rule or did he just record it? 

It's possible that the Rule itself was already widely known.  

 

In 1540 Sebastiano Serlio drew this sketch in Book IV of his On Architecture.* 

He wrote, "...
having drawn the cornice, divide the upper line from one side to the other in the middle, between A and B; drop half of this plumb from the middle to make C; then placing one compass point on C and the other on the side of the cornice A, arc to the side B; the highest point of the curved line will mark the required height for the pediment. A curved pediment can also be made with such a rule."*

The diagram shows the actual twine held tight at Points A and B. It is a Line with its ends dangling and curling.

 

Palladio doesn't describe this, but the roofs in his The Four Books of Architecture (1570) use the same pitch. 

 

Vignola's book on architecture was translated, of course.

This image, c. 1600, attributed to Vignola, comes from a book published in Spain.

 

 

 

 

 

 

His 5 Orders of Architecture* were translated into English and published by John Leeke in 1669. Vignola's portrait (Plate I)  is surrounded by a decorative frame topped by an extravagant  pediment.  It does not quite follow Vignola's Rule. Follow the red lines.

 

 

 

 

 

 

John Leeke' book  included 3 pediments attributed to 'Michel Angelo'. This one, the simplest, does seem to use Vignola's formula. The angle is the proper 22.5*. Did Michael Angelo know of Vignola's work?

 

 

 

A complete English translation of Serlio's 5 Books on Architecture, including the sketch of the pediment's layout, was available in the UK about 1720. 

James Gibbs probably had read both Vignola and Serlio.  He uses the geometry in the pediment of a Menagery, in his book, On Architecture*. Perhaps Gibbs includes the knowledge of this diagram when he writes that his 'draughts ... may be executed by  any Workman who understands  Lines'. 

William Salmon's book, Palladio Londinensis*, published in the 1750's, was intended for the London builder. Pediments are included; their proportions are measured in parts. Perhaps Salmon considered the understanding of geometry by London's builders to be scant, or that it was not applicable to London's tightly set row houses.

 

 

The rule for laying out a pediment came to the States with craftsmen as well with their pattern books. The Rockingham Meetinghouse, finished by 1797, is a classic New England meeting house:  plain and unadorned...

 

 

until you look at its doors. The pediments of the classical frontispieces follow Serlio's layout. 

 

I began my diagram here on the lower edge of the pediment's frame. If the layout is moved to the upper edge of that plate, the arc marks the top of the ridge of the pediment roof, rather than at the underside.

 

 

At about the same time William Pain includes the same arcs (lightly dashed here) and describes how to draw them in The Practical House Carpenter,* a pattern book widely available in the States.

Here is Asher Benjamin's simplification of Pain's engraving in The Country Builder's Assistant*, published in 1797.

 

 

 

 

 

 

This door front in Springfield, VT, c. 1800, was probably inspired by Benjamin's illustration.

 

 

 

 

 

The Industrial Revolution brought new tools and materials. Galvanized metal allowed shallow roof pitches which didn't leak.

 

 

 

Here's an example of a shallow roof pitch from Samuel Sloan's pattern book, The Modern Architect*, published in 1852 .

 

 

 

 

Sloan's Plate XXXV shows the steeple structure. The frame spanning the building uses the traditional roof pitch of Serlio's pediment (22*). The pitch of the roof is much shallower (15*)

For the next 50 years architectural style was giddy with the designs made possible by the Industrial Revolution.

 

 By 1900, the design possibilities made possible by 60 years of industrialization were taken for granted. Architects looked to Europe, especially the Ecole des Beaux-Arts in Paris, for inspiration, and perhaps a re-grounding in tradition.

 

William Ware wrote The American Vignola in 1903 as a guide for his students at the Architectural School of Columbia University. 

Here's his Plate XVII with many pediments. The dotted lines compare measured/built pediments in Greece and Rome to Vignola's standard.

 

 

 

 

 

 

 

 The 2 small diagrams on the right side Plate XVII are his codification to Vignola's Rule. 

 

 

 As I compiled these illustrations I found 2 caveats:

Owen Biddle* published his pattern book in 1804. Instead of a general rule for 'a pitch pediment frontispieces', Biddle wrote that the roof angle was 2/9 of the span. He also wrote that for 'the townhouse with a narrow front... the true proportions of the Orders may be dispensed with..." p. 34

William Ware noted that "...if a building is high and narrow, the slope needs to be steeper, and if it is low and wide, flatter." p. 45

And finally, this advice from William Salmon: "...when you begin to draw the Lines,... omit drawing them in Ink, and only draw them with the Point of the Compasses, or Pencil, that they may not be discovered when your Draught is finished..." p. 103.

 

*The books from which I have copied illustrations and quotes for this blog are listed in alphabetical order by author.

Asher Benjamin, The Country Builder's Assistant, Greenfield, MA., 1797, Plate 10. 

Owen Biddle, The Young Carpenter's Assistant, Philadelphia, 1805, Plate 15. 

James Gibbs, On Architecture, London, 1728, introduction and Plate 84.

William Pain,The Practical House Carpenter, fifth edition, London, 1794,  Plate 38.

Sebastiano Serlio, On Architecture, , c. 1545, Book IV, page xxviii.

Samuel Sloan, The Modern Architect, 1852,  Plates XXVII and XXXV.

WilliamWare, The American Vignola, W.W. Norton & Co., NYC, 1903, Plate XVII.

 

 

Stratford Hall, Part IV: Placing the Windows

Updated 8/26/2023

In the previous post* I wrote about all the construction details of Stratford Hall which William Walker, the Master Builder, had to work out before the masons could begin laying the walls.

They are all visible in this photograph: the brick pattern (Flemish Bond) and its variations, the brick headers over the windows in the ground floor and the main floor, the corner brick pattern and that around the windows, the cap at the shoulder, where the walls become thinner by one brick.

The Hall needed big windows on the main (family) floor above, smaller ones on the ground (service) floor below. As William Walker placed and sized the windows he would have considered all these constraints.

I wondered:

Was he drawing on paper, a board, a plaster wall, a framing floor? 

Drawings about framing can still be seen on cathedral walls and floors. So perhaps Walker did his layouts on the floor of the Hall.

He could have used the ground floor as a framing floor as soon as the foundation was set. The floor itself, his sketches and calculations, would become covered with pavers when the Hall was finished and ready for use.

It would also have been easier to lay out his ideas, check his dimensions for both floors from the inside, rather than working on scaffolding outside or in a shed nearby.

Walker used 5 equally sized squares to lay out Stratford Hall's floor plan. Perhaps he used a similar simplicity for the elevations. I drew squares.  

The red boxes show the interior of the wing. My tentative pencil marks are barely visible.

 

Simple squares (using the room height as the length) lay out the window locations for the Hall. Here is the main floor wall with 2 squares. They mark the edges of the center window for the main floor and the ground floor below.

 

 

They also locate the center of the window. The window frame is 2 squares tall - as noted by the diagonal line.

The size of the main floor windows and the width of the ground floor windows is set.

Squares of the same proportions, moved to the sides of the window, locate the outer edges of the windows on the left and right. Note: Square A-A and Square B-B.  

Those windows will be the same size as the center windows. There is plenty of room for the flat arches above the windows; the edging brick patterns are not crowded.

 

The only unknown is the vertical height of the ground floor windows and how far above the floor they will sit. Space must be given for the rowlock arches over the windows.

The Lines which located and sized the main floor windows extend to the ground floor. I've labeled them A-B, B-A, A-B to match what I drew earlier. 

Using the window width as a radius, and the floor of the lower level as the base, (the Line below 3) the center of the circle can be found, the circle and its daisy wheel drawn. It marks the brick arch over the window. It also intersects the Lines of the window widths  locating the height of the ground floor windows. 

The windows are 3/4/5 rectangles.

Walker trained as a joiner in Scotland at the time when James Gibbs, also a Scotsman, was there, and when Gibb's book, 'On Architecture', was published. Gibbs' book included plans for 2 'menageries'.** One was laid out with similar crossed squares, the other used the inside for its geometry as the exterior wall - shown here - was irregular, as is the exterior surface at Stratford Hall. Gibbs also used the 3/4/5 rectangle for layouts.

Copies of James Gibbs' book came to the Colonies. It is possible both William Walker and the Lee family had read the book in Virginia.

* Previous posts:

https://www.jgrarchitect.com/2023/06/stratford-hall-and-paul-buchanan.html

https://www.jgrarchitect.com/2023/07/stratford-hall-part-ii-geometry-of.html

https://www.jgrarchitect.com/2023/08/stratford-hall-part-iii-look-at.html

** My posts on Gibbs' geometry:

https://www.jgrarchitect.com/2021/12/james-gibbs-book-of-architecture.html

https://www.jgrarchitect.com/2022/01/james-gibbs-of-architecture-draughts.html

*  See previous posts:

https://www.jgrarchitect.com/2023/06/stratford-hall-and-paul-buchanan.html

https://www.jgrarchitect.com/2023/07/stratford-hall-part-ii-geometry-of.html 

**Personal note: I have been asked at workshops how I use practical geometry. Here is an example of how I would approach a design today. The geometry would tell me what size the windows would be and their spacing.