POPULAR SCIENCE 

 if we suppose it turned on its right side, or 



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if we suppose it turned on its left side, or 



if we assume it turned upside-down. 



The primary square thus assumes sixty-four guises, each of 

 which has in addition its corresponding reflected, or looking- 

 glass, form, thus raising the total to 128. 



We are not yet at an end of the juggling to which our 

 primary square so readily lends itself, for we can imagine its 

 corner sub-squares converted into successive horizontal lines 

 by supposing them unrolled in rotation (a, b, c, d) as shown 

 in diagram A, or we can imagine outer opposite half-sides 

 (a, b) and inner sub-squares (c, d) similarly unrolled as shown 

 in diagram B, thus producing two new primary squares : 



Primary Square. 



