The very top sail is the moonsail
1, 2, and 3 are moonsails.
Moonsails (or moonrakers) were very small square sails set on some clipper ships. They were always set above the skysail on the main, mizzen and foremasts. But most often, it was set on only the mainmast of most ships that carried this sail. If the sail was triangular in shape, this sail was called the skyscraper. These sails were a commonly unusual sail and usually only used on ships built primarily for speed and speed alone.
Ships known to have set moonsails[]
Young America-Clipper Ship, set on mainmast
James Baines-Clipper Ship,set on all 3 masts
Lightning-Clipper Ship,set on all 3 masts