[gallery columns=“1” size=“full” ids=“17536”]
Frontispiece to Charles Howard Hinton’s The Fourth Dimension (1904), a book all about the “tesseract” – a four-dimensional analog of the cube, the tesseract being to the cube as the cube is to the square. Find out more in our latest essay “Notes on the Fourth Dimension” - [bit.ly/1Revr2B](http://bit.ly/1Revr2B)