Quilt Notes: For an illustration of this design outlined on a full grid, along with general instructions on how to draft your own patterns, see the QUILTING AND PATCHWORK DICTIONARY by Rhoda Ochser Goldberg, 1988. The extra squares at the end of the wheel blades might also be interpreted as drops of water spinning off as the water wheel turns and therefore colored blue or green to provide that effect. The use of water for power goes back to ancient times, typically used to drive a millstone -- read more at waterhistory.org.