Hidden Initials and Camel Constitutionals

As members of the congregation will have seen, scaffolding continues to rise. Eagle Scaffolding, our fabulous riggers, have spent many days lifting pipes and planks to the roof from the garden, one or two at a time, and walking them from the west end down the length of the building. They build the outside towers first, then pass pipes through the window openings we made several month ago to erect a narrow scaffold on the clerestory walkway inside. The walkway is only 2’ wide, and so is the scaffolding. But it is as sturdy and comfortable as can be, thanks to our architect, Robert Bates (Walter Melvin Architects), and construction managers, Dan Wrzesinski and Lloyd Westerman of Westerman Construction.

In preparation for scaffolding the chancel windows behind the reredos, my assistant Bill Patriquin and I removed sections from the three windows. There is no access to them from the inside of the church – there’s no way to get behind the reredos, which was built years after the windows were first installed. Before removing the glass, I made a rubbing by taping paper over the panel and rubbing it with a crayon to record the pattern of the lead cames. This serves as a map of the window so that we know where pieces of glass belong after the window is removed. For all of the other windows, the rubbings will be done in the studios after the windows are taken out.




Here is the section I rubbed resting on the floor awaiting crating. Although it’s only about 2’ square, that one section weighs almost 30 pounds. There are 8 sections like this in each of the three lancets (the tall, thin vertical openings) of the center chancel window – 24 square panels in all, or 720 lbs. From the spring line up (the spring line is where the arch starts), there are an additional 36 sections in the tracery (the oddly spaced openings at the top). The stained glass panels are supported by bronze bars. The square bars that span the window on the inside are called saddle bars. The taller flat bars have an H profile. The sections of stained glass are held between the parallel legs of the H. There are 36 saddle bars and 12 H-bars in the center chancel window, totaling about 170 pounds. The entire center chancel window weighs, therefore, over half a ton.

Once the window sections came out,

we had a nice view of the back of the reredos. Some of the carving goes completely around to the back. One mason left his initials in the mortar. It looks like “J L G” or “J C G.”

On December 5, arriving via the 53rd Street Subway stop, I was

greeted by three camels out for their daily constitutional down

W. 53rd Street past the church. They were getting a break from their work at Radio City Music Hall, taking in the shopping on Fifth Avenue and munching a few trees along the way.

That same day we had a visit from the craftspeople who will actually be restoring our windows . The conservation studios for Phase I (the north side) visited the church for the first time. They’ve had to wait until the scaffolding was far enough along to allow them to get up close to the windows.

My assistant took the protective glazing (the plastic coverings) off one window so that we could all see the conditions on the outside of the glass. On the left you see the protective glazing still in place, looking yellowed and milky. On the right, it has been removed. The green arrow points to the aluminum mullion that held the plastic in place, and the pink arrow shows where it hit the stone frame. This is about 3” away from the surface of the stained glass.

Underneath the protective glazing, the lead came and solder holding the windows together is corroding. When lead corrodes, it becomes white. You can see the white spots all over the came. The center photo shows repair caulking in one of the tracery kites (we call them kites because of their shape, which is loosely like that of a child’s kite). This piece of glass is about 4” x 6”, but the caulking reveals only about 1” by 1”. The left photo shows the protective glazing that came off a section like this. For some reason, the contractor put 3 pieces of plastic over the glass – the rest of the window has only one layer.

The scaffolding construction is moving ahead at a good pace. The 60’ tower in the garden is almost complete.

It contains the stairs by which the craftspeople will get to the roof from the first floor of the Parish House.

The wall of the Museum of Modern Art is behind it on the left.

There will be a hoist in the scaffolded area between the stairs and MoMA to lower the windows down from the roof.

From the top level of the stairs, the craftspeople will walk to the right to the north-aisle roof.



On the north-aisle roof, the window scaffolding is going up.

This is the exterior tower on the western-most window.

The window itself is just visible through the pipes in the lower left corner.

The scaffolding tower for each window sits between the buttresses that support the walls and roof .

These scaffolding towers will be enclosed with plywood sheds before removals start in January.



We have also removed a section from the chancel windows behind the reredos in order to see how we can get to them for removal. There is no access to them behind the reredos, which is attached to the west wall of the church.






The removed section being crated. All of the windows come out in sections about this size.






A view of one of the reredos windows looking upward from the sill.

A detail of the reredos at the top of the window – notice all the little faces looking down at me!

In order to get the panel out of the chancel window, we had to remove some of the glass. The photos above show the contrast in thickness from one piece to the next. The glass in the right-hand photo is a hair less than 1/8” thick. This is the usual thickness of hand-made stained glass, which is called “antique” glass. (This term does not mean the glass is ancient – antique glass is still made today. It refers to it being hand-blown, which is an ancient process.) By contrast, the glass in the left-hand photo is almost 1/4” thick. This is called “Norman slab” glass. It was made by Powell’s of Whitefriars (the manufacturers of the window – they also made glass) by blowing the glass into square mold, then separating the square at the corners into small slabs that were about 6” x 8”. Slabs are very thick in center and thinner at the edges. Norman slab glass is made by only one or two companies today, and is very difficult to replace.

Scaffolding Tower Starts to Rise

The scaffolding has started going up. In order to reach the roof of the north aisle, which is where the window scaffolds will be, we started building access towers in the Parish House garden, between the Parish House and the Museum of Modern Art (whose glass wall you see in the photo). One of these towers is for people to reach the roof. The other will house an electric hoist that will be used to raise and lower equipment – and, more importantly, the windows – from the garden level to the roof.

We removed several panels from each window last week (September 24-27), to create an opening about five feet tall in one lancet.








The openings were filled with plywood, and the sections of stained glass were crated and stored, awaiting the studios that will restore the windows.



This is required to get the scaffolding inside. The scaffolding will be passed from the roof outside the windows through this opening to people in the catwalk, who will then assemble it in the narrow catwalk in front of each window. (There will also be scaffolding on the exterior.) Although it is very complicated to design and erect, by building the interior scaffolding this way, we will not interfere with activity in the nave and the church can remain open to the public.

The words associated with Gothic architecture (Saint Thomas is built in the Gothic style) and with stained glass are arcane and ancient, probably not terms that people are familiar with. The parts of the Gothic church are divided vertically (up the wall) and horizontally (along the floor). Vertically, the divisions are, from the floor to the ceiling, the “aisle,” the “triforium,” and the “clerestory.” In Saint Thomas, if you look at the north wall, the aisle extends from the floor to the first horizontal line at the lower ceiling. The triforium is above that. It is a row of short arches, where the lights are presently located – they have been temporarily moved from the clerestory for the duration of the project. The clerestory is above that, where the largest windows are.

The divisions of the floor plan are similarly regimented. At the west end of the church is the chancel, which is raised above the level of the pews. This is where the altar and altar rail are located. The next space toward the east on the raised area is the choir. Here the pews face each other so that the members of the choir can see each other and the organist. The organ console is also in the choir. Directly in front of the choir, from the steps eastward to the first set of doors, is the nave. From the first set of interior doors to the exterior front doors is the narthex. The wall of woodwork and glass between the nave and the narthex is the narthex screen.

Your Questions Answered

Q: Why do we need to undertake restoration of our windows?
A: Two main reasons: the lead used in windows during the early to middle twentieth century was very pure and soft. It deteriorates within about 70 years. Harder lead alloys, like those used in the Middle Ages that contained additional metals like tin and silver, typically endured for at least a century. But even medieval windows have been releaded numerous times. Second, the installation in the early 1980s of protective glazing— though common at that time— has accelerated the deterioration of the lead by trapping heat and moisture.

Q: OK, but why do we need to do it now?
A: As part of the Parish master building and maintenance plan, I’ve been monitoring the state of Saint Thomas Church’s windows for five years. Even during that time, the deterioration has been marked—sagging and bowing of the panels in some cases leading to cracking and breaking of glass. The longer you wait to begin the work, the greater the chance of substantial damage and the higher the cost of restoration.

Q: Some of these windows have been in place less than 40 years— how long will the repairs last? A: Today we understand more about the aging of materials, so we will be using a lead came of a stronger alloy than was originally used. This should last at least 100 years.

Q: How does this project’s scale compare to others you’ve worked on or studied? A: With 8,600 square feet of glass, almost 500,000 pieces of glass, and 12 conservation studios, this will be the largest complex stained glass window restoration project ever undertaken in the United States.