This post is being rewritten. When I finish I will change the date. Much of my revision is due to an excellent exploration of the attic and the trusses in early 2020. 7/21
The Rockingham Meetinghouse was begun in 1787, dedicated in 1798.
I had done some preliminary analysis of the design and frame and realized in 2014 that I needed to see it. I wondered if it would be as spare as the Rocky Hill and Sandown meetinghouses.
The site, on top of a hill with a view all around, emphasises the simplicity of the structure. One can only come to it from below, and like many 18th c. New England buildings it sits upright and confident. It is very impressive.
I returned in 2018 and early 2020, I updated the geometry as I learned more. I revised the drawings when I gave a Zoom presentation in spring, 2021. Each time the geometry became simpler. I realized that a 'simpler' design and frame equaled a 'easier' timber frame for a crew of local citizens to erect.
The Town Fathers specified a building 44 ft. by 56 ft. The HABS drawings read 44'-4" x 56'-6". The difference could easily be the addition of the sheathing and siding to the frame. The porches (the end staircases) are square: 12'-2" x 12'-2".
The difference could also be that the rule used then and the one we use today differ slightly.
General Fuller, the master builder, was also the architect, engineer, framer. He knew the meeting house required an open space in the middle so everyone on the floor and in the balcony could see the preacher in the pulpit - and be seen by him. The pulpit was centered high on one wall, a window behind,the balcony on 3 sides.
He laid out a 3/4/5 rectangle. noted here in red. Then he laid out a square in the middle which defined the open
space and divided that into thirds to set the
columns for the balcony and the posts for the frame. See the black square and columns.
He extended the column spacing - the dashed black lines - to place the posts on the front and rear walls.This made the balcony the same depth all the around.
The porches are squares set in the middle of the west and east walls. The exterior posts were set at the porch corners, not at the 1/3 points of the wall. This also allowed for 2 windows on each side of the porches.
The front elevation can be seen as the square divided into thirds. The arrows point to where the diagonals cross, the center lines of the windows.
The porches' widths are half the square. The only deviation is the center bay which is a 3-4-5 triangle.
The roof is 2 3-4-5 , shown in green. The drawing says a 9/12 pitch - the little triangle to the right of the roof. A 9/12 pitch is 37*. A 3-4-5 triangle is 36.5*. I assume the delineator was not aware of the use of geometry.
The side view shows squares begun from each corner, crossing, both divided into thirds. At the third of each is the wall for the porch.
Here is the main door. Its height and center line are the determining dimensions.
From that comes the circle, its 2 squares, and the next smaller circle and square that come from those. The crossing points determine the pilasters, the height and width of the door, the width of the architrave.
Last picture: Just as at the Rocky Hill Meeting House the eaves on the porches bump into the windows. Neither master builder had solved that problem.