From facing lines: Ends "double circulate" and move ahead to Star Thru with the next one they meet. Simultaneously, the centers Star Thru and California Twirl. Finishes in different formations depending upon the arrangement of sexes in the original lines.
COMMENT: Another movement called Percolate was adopted as one of Challenge Dancing's Basic Calls.
George Hinkel 1971
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.