  The Brocard porism is a known 1d family of triangles inscribed in a circle
and circumscribed about an ellipse. Remarkably, the Brocard angle is invariant
and the Brocard points are stationary at the foci of the ellipse. In this paper
we show that a certain derived triangle spawns off a second, smaller, Brocard
porism so that repeating this calculation produces an infinite, converging
sequence of porisms. We also show that this sequence is embedded in a
continuous family of porisms.
