Sunday, October 20, 2019

" People with Compasses"

"People with Compasses" is really: "Portraits of Builders and Architects with Compasses".
I periodically check to see what the internet has to say about geometry. Under the query 'people with compasses' was a drawing of a person made with a compass.  That's all. 
I realized I could easily add to the dialog.

My presentations about Practical Geometry begin with portraits of men involved in construction; all of whom are holding a compass as the symbol of their profession.  Their contemporaries knew they were builders, master carpenters.
Sometimes they were called 'architects', a title synonymous with 'master builder'. Check out the OED..
Those pictures also belong in this blog.

Here are the portraits I have found:

Sabastiano Serlio, 1475-1554, with his compass
a posthumous portrait c. 1575 by Bastolomeo Passerotti  now in the Martin von Wagner Museum, University of Wurtzburg.

A post about him is here

Andrea Palladio, 1508-1580, an engraving probably copied from a painting, c. 1575, by his friend, Giovanni Battista Maganza.

My first post on Palladio is here:

James Gibbs, 1682-1754,  English architect who was responsible for the church, St. Martin's in the Field, 1722, in Trafalgar Square, London,  and many other buildings. Engravings of these buildings were collected in A Book of Architecture, 1728.
The book came to the Colonies and influenced many master builders, including Christ Church, Philadelphia; St. Mark's, NYC; and the Old First Church in Bennington, VT.

Andrea Soldi, Portrait of James Gibbs, ca. 1750 (Edinbrugh: National Galleries of Scotland, Scottish National Portrait Gallery).

This is James Watt, 1736-1819, Scottish engineer.  This sculpture was made soon after his death. He holds his compass.
I wrote about him here:

Credits for the  sculpture are given there.

William Buckland, 1734–1774.  His compass is on the table below his hand.

Artist: Charles Willson Peale,  painted in 1774, reworked, 1789, Yale University Art Gallery

I wrote how he transformed Gunston Hall here:

John Haviland, 1792-1852, was a architect in Philadelphia. I have written about Watt and Haviland here:

Credits for the painting are given there.

Edward Shaw wrote The Modern Architect, in 1854, published by Dayton and Wentworth, Boston.  The frontispiece of the original edition was black and white. This colorized version appears on the cover of the Dover Publications reprint published in 1996.

Here the architect used his compass as he confers with the builder. On the ground is a larger compass with a armature.

For more on Shaw:

le Pere Soubise, legendary founder of the Company of traveling Carpenters in France. a lithograph , 1882

Here is the credit in French:
Lithographie en couleurs représentant le Père Soubise, fondateur des Compagnons passants Charpentiers du Devoir, des Couvreurs et des Plâtriers, tenant un plan d'architecte et un compas.
une lithographie représentant le portrait de Salomon conservé au musée des Beaux-Arts de La Rochelle (MAH.1943.6.1)

I wrote about him here:

Here is God with a long compass, an illustration in a 13th century manuscript.  However, here God is measuring the world He has just created, not planning some remarkable construction.

Compasses have been found in Pompeii along with pens and ink wells, tools for layout and design. I don't have an image of them yet.

Thursday, October 10, 2019

Compasses as Symbols of Construction

Compasses are regularly portrayed in construction images, and are also regularly ignored.

In October, 2018, the Preservation Trades Network (PTN) met at the National Park Service Historic Preservation Training Center in Frederick, Maryland, for its annual workshops.

I gave 2 presentations on the use of compasses in historic layout and design. More than 30 participants practiced their geometry - with enthusiasm. They asked good questions.

PTN workshops were held in the shops, the yard and storage bays, and an office of the Training Center. Around us were the HPTC logos.
They all included a trowel, a plane, and a compass.

As posted here: 
top: on a brochure
middle: real tools mounted on a board hung on a wall
bottom: an image posted on a bulletin board

I asked the staff who came to my presentation what they knew about using a compass. They told me: not very much.

The image of  a compass is there, along with a trowel for plaster, masonry, and stone work and plane for wood working. The compass as an equally important tool for layout and design. The understanding of how and why to use one has been lost.

 In September, 2019,  PTN joined with Historic Environment Scotland to hold the International Preservation Trades Workshops (IPTW) at the Engine Shed, Stirling Scotland. I gave 3 presentations with slides and hands-on practice drawing layouts and elevations without numbers,  using only a compass, a straight edge, and a pencil.

Our final evening we dined in the Banquet Hall of Stirling Castle, historic home of Scottish kings, including Mary, Queen of Scots, and James VI who became James I of the United Kingdom.  (No, the roof trusses were not this pink! just what my camera saw!)

 Before dinner we toured the castle which is set high above the land and the river.

It is beautifully cared for; the rooms used by the royal family furnished with fascinating furniture and tapestries depicting the time when Mary Queen of Scots and James VI lived there. The signage is excellent: clear, colorful,  with historically accurate graphics and information.

 Even jokes were in period dress: These plaques were beside the  restroom doors; a medieval beast which might be a griffin was watching from the newel post.

This poster was in the courtyard. I liked the images:  the tools in use, the appropriate clothing, and surroundings. visually interesting and easy to understand.

The text explains the work. Except for that compass the master mason holds under his arm.  It is perhaps 24 inches long, with brass fittings and an armature to set the span. This is a serious instrument.
No explanation is given for its use.

I think people simply don't understand how a compass was used. No one  asks how the project was organized, how it was planned and set down so that all the craftsmen  could reference what was to be built.

How did they share their understanding of the scope and detail? The master craftsman laid out the design of the work.
He used his compass to accurately draw and explain his plan to  the other workmen.
 I looked on the internet for the proper name of the 'armature' on a compass used in construction. 'Hinge' is sometimes used but that refers to the part where the legs join.  In the 1920's the 'arm' had become a bar with an adjusting screw; the compass called a 'spring bow".  
Because there is so little written about compasses used in construction I may need to revise this post as I learn more. 

Bow compasses

Page 614, Audels Carpenters and Builders Guide #2, Theo. Audel & Co., Publishers, NY, NY, 1923

Tuesday, September 24, 2019

John Haviland and James Watt with their compasses

Portraits of master carpenters and architects with their compasses are part of my presentations: how I show people that we really did use geometry and compasses for design and layout.

I collect these images as someone else might collect old maps or historic recipes.

This is John Haviland, 1792-1852, an emigre to Philadelphia. He designed many Gothic inspired public works around Philadelphia.
The portrait is now in the NY Metropolitan Museum of Art. I have cropped it so his compass (which shines) can be clearly seen.

 Like Owen Biddle, Haviland taught 'carpenter's assistants' in Philadelphia. In 1833, 28 years after Biddle's death, he reprinted Biddle's pattern book.
He also wrote his own 3 volume pattern book, beginning in 1818. The Met has one copy; the other is in a library in Australia.I have not yet read it.

James Watt  (1736-1819) was a famous Scottish inventor and mechanical engineer.

Soon after he died Sir Francis Chantrey was asked to create this sculpture to honor him.
Watts is shown designing the double acting beam engine. a new and powerful steam engine which changed manufacturing. It drove machinery all over the world.
Note that he is designing with his compass.

This sculpture sits in the entry hall of the National Museum of Scotland in Edinburgh. It is on loan from the Heriot-Watt University in Edinburgh, named after him and George Heriot.
(Heriot (1563-1624) was a goldsmith who left his money to educate the orphaned sons of freemen in Edinburgh.)  

I had come to Edinburgh after presenting on Practical Geometry at the IPTW 2019 in Stirling, Scotland, September 5-7. I was enjoying the museum with friends, including a 3 yr old who needed to visit the sharks and dinosaurs, when I came upon James Watt.
What fun to share a 3 yr old's enthusiasm and come across one of mine in the process!

Friday, June 14, 2019

Corn Cribs for the Indiana Barn Foundation Workshop and Keynote

July 19-20, 2019, I will give a workshop and the keynote address on Practical Geometry for the Indiana Barn Foundation at the Oakwood Retreat Center in Selma, Indiana.
Their website is :

The picture they used for their announcement is the one I use on my website: It's a farm house north of Boston built about 1830 which was designed using a wonderful combination of circles and squares. I hadn't planned to include it in the talk but now think, of course, I will.

One post about this house is here:

I might have chosen this picture of my corn crib as it is a barn out-building - and because it is red!

My post about the corn crib here:

2 more corn cribs will be part of the lecture and probably the workshop.
They are from different construction traditions in different parts of the States. utilitarian buildings, built without frill, their forms easy to understand and read. They all use geometry differently.

The front of the Knight corn crib in Flatbrookville, Sussex County, NJ, shown here, is one of 3 HABS photographs of the crib. taken in 1969.

This is the quote which accompanies the photographs and drawings.
"Within this farm group that developed between 1826 and 1910, two significant structures are the corn crib and hog barn. The corn crib is an excellent example of early corn cribs in the Delaware River Valley, featuring a frame that is hewn and pegged."
This corn crib in New Jersey is therefore about the same age as mine in Vermont; they are not the same.

Here are the HABS drawings.

 It is so different from  my Vermont corn crib that if the sides did not slant I would have thought it just a shed.

The layout is governed by its width. The posts are placed  by 2 red squares and the arc of the squares' diagonals.
The same sized  2 red squares and the arc of the diagonal determine the height of the crib and its roof.
A crew could lay out the plan on site with twine,
then layout the section of the crib on a framing floor with twine,  cut the frame and assemble it on site.

The slope of the walls is set by the square: the sills - noted in red - are located inside the lower corners of the square, the mid-plates - also red - are located on the outside of the upper corners. the slope continues up to the height of the upper square.  The red line on the right indicates that the height of the wall is divided in half by the center girt.
 The crib design could have begun with a line and its perpendicular. The line could be the width; the perpendicular could have been one wall. Then with twine the arcs - in red - could have located the posts - also in red.

The upper brace in the section falls on the point where the diagonals crosses the arcs of the side of the square - noted in red. 
I have seen this only once in New England. The center brace is on the line of the squares.
The lower brace is not located on the arcs. Instead it is centered between the floor and the mid-brace.

To see the HABS photographs and drawings, type the name and location "Knight corncrib... " into your browser.

Sunday, June 9, 2019


 June 9, 2019
subject to updating

This bibliography was first complied to accompany a lecture on Practical Geometry in 2016. It is now available whenever I present.

A list of books by and about builders and architects who used Practical Geometry; many are primary sources.
At the end are other sources, websites, and credits.
It does not include books I refer to in a specific post. For example: Audel's Carpenters and Builders Guide, Theo Audel & Co. Publisher, NYC, 1923, is footnoted at the end of that post:

A few are books on architectural history and technology which I reference regularly:  Bannister Fletcher's History and Knight's American Mechanical Dictionary.


Benjamin, Asher. The Country Builder’s Assistant, 1797, Dickman, printer, Greenfield, MA –
     reprint by Applewood Books, Bedford, MA.
                     *The American Builder’s Companion, 6th edition, RP &C Williams, Boston, 1827
Biddle, Owen. *Young Carpenter’s Assistant, published by Benjamin Johnson, Philadelphia,
Charles, FWB, The Great Barn of Bredon, Its Fire and Reconstruction, Oxbow Monograph 76,
     1997, Oxford Books, Oxford, UK.
Fletcher, Bannister, A History of Architecture on the Comparative Method, Charles Scribner’s
      Sons, NY, 17th Ed. 1967.
Gibbs, James. *Book on Architecture, London, 1728
                       Rules for Drawing the Several Parts of Architecture, printed by W. Bower for the
      author, London, 1732, ECCO print edition  
Green, Bryan Clark. In Jefferson’s Shadow, the Architecture of Thomas R. Blackburn, Princeton
       University Press, NY, 2006
Harris, Leslie. Robert Adam and Kedleston, The National Trust, London, 1987.
Knight, Edward H. American Mechanical Dictionary, Vol I, II, III; J.B. Ford & Co. NY, 1874.
Nicholson, Peter. The Carpenter’s New Guide, 1793, London; 10th ed., Philadelphia, 1830.
Palladio, Andreas. *The 4 Books of Architecture, 1570, translated and published by Isaac Ware,
      London, 1738.
Serlio, Sebastian. On Architecture, Lyon, France 1530, translated in1611, available on-line. 
       Translated by Vaughan Hart and Peter Hicks, 1996, Yale University Press, New Haven
Shaw, Edward. *The Modern Architect, Dayton & Wentworth, Boston, 1854
Smith, Laurie, The Geometrical Design of St. David’s Cathedral Nave Ceiling, A Geometer’s
      Perspective, The Geometrical Design Works, 2017, printed Exeter, UK.
Vitruvius, Marcus. *The Ten Books on Architecture, c. 10 BCE, translated by Morris Hicky
      Morgan, Harvard University Press, 1914.

*Reprinted by Dover Publications, Inc., Mineola, NY

     HABS drawings, Library of Congress, Washington, DC
     Denison Bingham Hull, Old First Church, Bennington, Vermont, c. 1935.
     James Platteter, barn frame for Green Mountain Timber Frames, 2014
     All others: Jane Griswold Radocchia
Web sites: (you are here!)  and
for Laurie Smith: and