Verifying plumb in Notre Dame

Master masons prized the rectilinear;

To reach for the sublime they verified plumb;

The plumb bobs are in the Lazarus window,

And in stain-glass panels of babel-building.

From a cornerstone, in vertical courses,

They mortared stone after shaped stone to meet

The imperative of mural rectitude:

No bulging rifts to deny consecration.

To build a wall straight was to live a straight life;

So the plummet sought pure planar perfection;

Raising the space aloft to heavenly heights,

They built a clerestory of coloured lights.

In the luminous, moral and mural order

Fused living no-longer-insensible stone;

Knowing how a stretching stone structure behaves,

They sought to stabilise by thickening walls:

Inside, by fixing responds and pilasters;

Outside, flying buttresses resist the thrust

Of the stone arches, the high strung ribbed vaults;

The inside and outside of the perfect walls,

They clothed in a mantle of badigeon.

The truth is there is no state of perfection;

The structure is not a simple mass at rest;

It is an interlacing of moving forces.

The cathedral wants to flip on its vaulted head;

To roll like the hailstones spilling down its roof;

Trying to fall out of the line of God’s gaze,

The piers and columns lean out in Notre Dame.