Tuesday, January 11, 2022

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

This post will be revised. There is a much simpler way to design this using the 3/4/5 rectangle. I will transferring my sketches to drawings.  3/28/22

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

James Gibbs' On Architecture included 2 options for a menagery. In Part 1 of 2,  I wrote about the 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 read in Gibbs' drawings? What could I read? Do I understand Lines?

 

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. 


The floor plan begins with the central form: the porch and caretaker's quarters.  Note that the red lines for the left and right sides of the rectangle are located at the back of the fireplaces. Perhaps this is information for the mason: he will start his work there.  

The depth of the building (the red line of the right side) is the radius for the arcs which cross at the wall on the left side. I have drawn the left line that completes the square that the arcs determine. The intersection locates the left wall noted by a red line with arrows.

The shape comes from the circle and its daisy wheel.  It is a rectangle created by the 6 points of the daisy wheel on the circumference.

In case the diagram is not clear I have added notes.

Begin with a circle and its daisy wheel. 

The radius of the circle always steps off around the circumference 6 times: 6 points on the circumference, 6 daisy petals made by the arcs of the circle.

 

 

Connect 2 points (solid black line). This will be the length (front to back) of the central form. Add the Lines ( dashed black lines ) perpendicular to the first Line.

                                                                         

 

If the central form were to be a square, where the dashed lines cross the daisy petals mark 2 more points. The dashed, black vertical line is the 4th side of the square: each side is the length of the radius.

 


 

This central form is not that wide.  James Gibbs choose to use the 2 vertical points of the daisy wheel to locate the Line for the left side of the porch and the caretaker's quarters. The black box is that rectangle.



The rest of the layout is based on the interior space. 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. This makes the porch a little more gracious. It is also the way a mason sets lines today, building beside his lines. 


To determine the location of the wings to the main body of the menagery Gibbs divides the rectangle into 8 parts.

Here is the diagram showing how to use Lines to divide a rectangle into 8 equal sections. 

I call this 'The rule of Thirds' because artists use this diagram as a design tool and that;s what they call it.  It's the 3x3 pattern that appears when we edit cellphone pictures. That pattern is 1/3. Here the division is into 1/2, 1/4, and 1/8. **


The wings of the menagery are set back 1/8  the depth of the main block in the front and the back.  I've drawn the open porch divided into 4 equal parts and extended the Lines to show the depth of the wings' setback. This offset is used on both wings, front and back.


 

 

The wings are themselves both 3/4/5 rectangles. They are square: a 3/4/5 triangle always has a 90* corner. The diagram shows how to layout a 'right triangle' using Lines.

 

 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!)  

 

The layout for the 3 arched openings on the pavilion's porch also uses the Rule of Thirds. 

Here is the diagram above turned 90*. Note where the red lines cross the
black lines above my red dashed line.  Those points divide the square into thirds. Drop a vertical there (see red lines above)  to mark the columns' center line.

 

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, some of which, for example the 3/4/5 rectangle, are used today.


 The elevation? It's 4 squares and the same pediment layout that  Gibbs used on the menagery design which was built.


 

 Gibbs began the elevation from the same inside dimensions he used for the floor plan.
A note: the windows are centered on the rooms' inside wall, but not on the exterior width of the wing.  The quions 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.

** 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