Whatever he knew he had learned

from nature, how even things

that seem at first fragile derive

strength from structure –

an insect’s wing, or a leaf,

its membrane stretched across

a framework of ribs and veins.

 

The simplest grasses, barely

noticed, assume their burdens

like trees. A small shell’s

convolution implies a flight of stairs.

You can roll out a roof like waves.

The world’s the laboratory

of stresses and strains.

 

Unwilling to trust designs on paper,

– if he could re-construct

what’s already there – he measured

loops of chain which, inverted,

revealed perfect arches;

or balanced tiny bags of shot

like vaulted tons of stone.