http://www.engineering.com/DesignerEdge/DesignerEdgeArticles/ArticleID/12978/A-Low-Cost-Solution-for-Storing-Solar-Energy.aspx?e_src=relart
"The voyage of the best ship is a zigzag line of a hundred tacks. See the line from a sufficient distance, and it straightens itself to the average tendency."
Waldo Emerson
Scratches to Sketches