of the bird opposite. Thus, if the point of view of the drawing is that of another bird, there are four birds and three horns, with one of them being shared between two birds with the same vertical orientation. In order to portray three mutually orthogonal verticalities from the point of view of a third bird, the bird opposite that would have to be rotated 90 degrees, and the window adjacent to the viewer show the naturally oriented landscape behind the hanging horn. The previous month (December 1946), Escher created a mezzotint called Another World (Other World Gallery). The image in that print is the same as this one except that the arches continue on as an infinite corridor. The bird/human sculpture is a real sculpture which was given to Escher by his father-in-law. This sculpture first appears in Escher's 1934 lithograph Still Life with Spherical Mirror. The picture is featured in the cover of the 1965 edition of Italo Calvino's Cosmicomics. Sources External links Other versions of Another World Works by M. C. Escher 1947 paintings Woodcuts