James Gibbs' Of Architecture, Draughts for a Menagery, Part 2 of 2

 

The  second menagery in James Gibbs' On Architecture* was never built.  In Part 1 of 2,  I wrote about the first one which was built at Hackwood Park, an estate near London. It is still standing.

Here is Gibbs' portrait with his compass, the mark of his profession. 

Gibbs' expected "any Workman who understands Lines" to be able to execute his designs. What would a workman have seen in Gibbs' drawings? What could I see? Did I understand Lines?

The first option was so simple. I was looking for an equally direct layout for this second design. I could find only complex solutions. They worked, but they were not direct. For 3 months the obvious design  was right there and I couldn't see it. I put the puzzle aside several times.  

This 'menagery' was to be a welcome destination for those strolling through the Hackwood Park estate grounds. Built of stone, the menagery would not have been as dark as this image.The 'draught' elevation accentuates the quoins and articulated arches, to give the workmen the necessary information. 

Like the design which was built, the pavilion required a gracious porch with a room on each side: one for serving and drinking tea, one for the quiet perusal of books about nature, especially birds. The living quarters for the staff who took care of the estate's pheasants were around the back. 

Today a plan usually lays out the exterior dimensions. Here the exterior is to be stone, perhaps ashlar or split, with rusticated, oversized  arches and  quoins (the corner blocks). Using inside dimensions to layout the plan allowed the exterior dimensions to vary.  

Note that Gibbs' drawing of the exterior stone facade is structural. The blocks interlock on the corners; the arches and key stones interlock with the wall. 

 

The floor plan begins with the central form: the porch and caretaker's quarters. Its size is determined by 2  3/4/5 rectangles overlapped at their mid-points. 

Gibbs assumes the workmen who might copy his 'draught' know how to build walls; he is not providing a construction document.

The wall between the porch and the living quarters is set beside the center of the rectangle found by drawing the diagonals of the main pavilion. This makes the porch large and gracious. It is also the way a mason sets lines today, building beside his lines. 

 

A workman could true his rectangle to center the doors on the walls.  Note the red line.

 

 

 

 The lines from the corners to the center locate the center lines for the arched columns. 

I have left out many lines here for clarity. They could be added to check the work.

 I call this 'The rule of Thirds' because artists who use these lines as a design tool call it by that name.  It's the 3x3 pattern that appears when we edit cellphone pictures. **

 

The wings of the menagery are set back 1/4 of the depth of the main block in the front and the back - note the red line with arrows As the geometry here is the 3/4/5 rcctangle it is fitting that the wings' length is proportional to the main pavilion's length: 6/8 or 3/4. 

 The wings are themselves both 3/4/5 rectangles.

 

The 3/4/5 rectangIe was a common way to add a wing to an existing building. If the mason set his length against the central form at 4 units and his width at 3 units, his wing would be square against the main block. His stone work would be true.  I have drawn the 3 x 4 units here. I have also left my pencil marks for further information (enlarge the drawing!) 

 While this menagery design is more complex to write about than Gibbs' other design*, it is quite easy to lay out with a compass and straight edge. A trained workman would have known the steps. The 3/4/5 rectangle and the Pythagoras Theorem are used today.

 The elevation? It's 4 squares and the same pediment layout that  Gibbs used on the menagery design which was built. The inside dimensions govern. The red arcs drawn show the floor width of the rooms are also the height of the elevations.    

A note: the windows are centered on the rooms' inside wall, but not on the exterior width of the wing.  The quoins are such a strong visual vertical that they appear as an anchor. The windows were centered on the rest of the wall.

The pediment is drawn  following the rules described by Serlio. For step by step instructions, refer to Part 1 of 2 of this post of the draughts for the Menagery.*

 * Gibbs' book On Architecture, published in 1728, includes 150 plates: plans, elevations, sections and perspectives of buildings Gibbs had designed and built. The quote is from his introduction, page i. A reprint is available from Dover Publications.

Part 1 of 2, the post for Gibb's design of the Menagery which was built is here: https://www.jgrarchitect.com/2021/12/james-gibbs-book-of-architecture.html

** I've posted about The Rule of Thirds in more detail here: 

https://www.jgrarchitect.com/2020/08/lesson-6-rule-of-thirds-part-1_21.html

https://www.jgrarchitect.com/2020/08/lesson-6-rule-of-thirds-part-2-serlio.html 

James Gibbs' Book of Architecture, Draughts for a Menagery , Part 1 of 2

 

Here is the portrait of James Gibbs, British 'architect', though that title was not used. In 1722, the Commissioners of the new St. Martin in the Fields Church appointed him to be 'Surveyor of the Work'.

Note that he is holding the tool identifying his profession, a compass. His fingers hold it as if he is about to use it. *

 

His portfolio, On Architecture, published in 1728,  includes 150 plates: plans, elevations, sections and perspectives of buildings Gibbs had designed and built.  

The Introduction - 25 pages long - describes each plate, but first Gibbs writes, "... such a work as this would be useful for... Gentlemen as might be concerned with building, especially in the remote parts of the Country, where little or no assistance for Designs can be procured." These "Draughts of useful and convenient buildings... may be executed by any Workman who understands Lines, either as here Designed, or by some Alternation..."** 

 

I wondered if I, like those Workmen, understand his Lines. 

Could I 'read' how Gibbs used Practical Geometry? 

Could I see how his manipulation of geometry could be copied by others in layout and design? Yes, somewhat. I started with a very simple design, his proposal for a building to house pheasants and their caretaker, Plate LXXXIV. ,

But first: what he is best known for:  St, Martin in the Fields, in Trafalgar Square, London. This is the front elevation. Gibbs included floor plans, sections, the other elevation as well as a perspective, 7 plates in all. 

 

The book came here, to the Colonies. Plates 29 and 30 with  images of steeples, especially, inspired our church builders.

I am learning to understand the Lines of these.

 

 

 

A Building for the Menagery

Plate LXXXIV

"Two Draughts of a Building for the Menagery at Hackwood. The Portico of the one is with Arches, and the other with Columns; having a room at each end, and two rooms behind for the person that looks after the Pheasants. That with the Columns is built."**

 

I looked at that building, the one with the columns.

Its plan is composed of squares, all the same size. The wall thickness makes them appear to be different. 

The layout is simple: 6 squares. 4 in the front with 2 crossed at their half points. Center 2 behind the front ones. Center the windows and fireplaces. Add a door, a stair, a nice front stoop.

The proportions of the center Portico is 3/2: the depth 2, the width 3. Or, one square and half of the next one. The Lines of the crossed squares locate the columns. The columns divide the portico into thirds. 

See below for a step by step explanation. #

This plan is practical: the fireplaces are located so that 4 flues can be joined into 2 chimneys. The stair is offset to allow a wall to be easily set beside the centered window - if the stair had been centered on the back wing the left wall of the stair would have had to jog to miss the window. Living quarters often had a Hall - here on the right - sightly larger than the Chamber - on the left.

 

The height of the walls in the Elevation is based on the width of the square used to layout the plan.  The squares are crossed at the portico just as they are in the floor plan.

 

The pediment is laid out  by dividing the upper line of the cornice A-B in half, dropping this length plumb in the middle C-D, placing your compass with one point at D, the other at B, and drawing an arc B to A. " 

 

Sebastiano Serlio wrote in Complete Works on Architecture and Perspective, c.1555: "The highest point on the curved line will mark the required height of the cornice."  This sketch, almost an after thought, is at the end of a discussion about Doric proportions  in Book IV, On the Five  Styles of Buildings.

Gibbs might be copying Sebastiano Serlio. Or perhaps this way of sizing a pediment was standard knowledge, part of what Gibbs means when he writes of a 'Workman who understand Lines'.  This way of determining a cornice is  used by Wm. Salmon in Palladio Londinenses, explained in Asher Benjamin's pattern books, and seen over doors in Georgian New England.

This Draught with Arches, is Gibbs' second design, the one which the owner chose not to build. 

 

Hackwood Park is in Hampshire, UK, about an hour southwest of London. It appears to be private property and has been owned by several families since 1728.
For a picture of the menagerie in 2001 see: https://historicengland.org.uk/images-books/photos/item/IOE01/07844/01

# For a refresher on how Lines can divide a square, try this: Upper row, left square divided into 2 halves: your goal.

Begin with a line and its perpendicular. Lay off your dimension: here, 4 squares, A-B. Swing your compass and mark C.  With your compass point at B, swing an arc. Then with your compass point at C, swing another arc. The arcs will cross at D. Now you have a square, all side of equal length. 

With your compass point at C and then D, swing arcs to cross at E and F. Now you have 2 points that allow you to divide your square into halves - the dashed line.  Place one side of your second square (darker black outline: E-F-G-H). 

Note that the compass width, its setting,  is the same for the whole layout.

The last diagram, lower right corner: When I drew it I used 'geometric shorthand'. 2 crossed squares with diagonals to show how they related to each other.

This shorthand is very much like the notations we find when we uncover geometry on old frames and sheathing. They knew what they said. We've forgotten the language.

Note: I have found out that, of course, the design had nothing to do with the size of the pen required to house the pheasants.  The pheasants lived in a  wooden lattice work enclosure. 

The menagery had a room for making and drinking tea and another for a library on flora and fauna. It would have been a destination for strollers, perambulating the gardens and grounds of the estate. So the requirements were 2 rooms, both with windows for light and fireplaces for heat and cooking,  a sheltered space for viewing the garden in sun or rain. And, yes, living quarters for staff, but invisible, ticked around the back.

With such simple requirements the menagery could be an abstract architectural ideal, a sculpture to show off the owner's erudition as well as a place where guests were welcome to dally. 

*For James Gibbs and his compass in context   https://www.jgrarchitect.com/2019/10/people-with-compasses.html.

**For the books, including Gibbs' On Architecture : https://www.jgrarchitect.com/2019/06/bibliography-including-websites.html.