Question 1

What is the Peirce quincuncial projection?

Accepted Answer

It is a conformal world map projection devised by Charles Sanders Peirce in 1879 that arranges most of the globe inside a square.

Question 2

Why does this world map form a square?

Accepted Answer

The projection transforms the sphere through a mathematical construction that places one pole at the centre and divides the other across the four corners.

Question 3

What does the projection preserve?

Accepted Answer

It preserves local angles except at a small number of singular points, while area and distance distortion increase in other parts of the map.