Forces on sails to stay within the limitations of a craft's stability and power requirements, which are functions of hull (for boats) or chassis (for land craft) design. Sails derive power from wind that varies in time and with height above the surface. In order to do so, they are designed to adjust to the wind force for various points of sail. Both their design and method for control include means to match their lift and drag capabilities to the available apparent wind, by changing surface area, angle of attack, and curvature. Wind speed increases with height above the surface; at the same
Sixty Sails Handicap Sixty Sails Handicap The Sixty Sails Handicap is an American Thoroughbred horse race held annually during the third week of April at Hawthorne Race Course in Stickney/Cicero, Illinois. A Grade III event open to Fillies and Mares, age three and older, it is contested on dirt at a distance of one mile and one eighth (9 furlongs). Inaugurated in 1976 at Sportsman's Park, in 2004, the race was moved to Hawthorne Race Course. It was named for the racing filly Sixty Sails, owned by John Petre and Chris Vodanovich of New Orleans. Since inception, the Sixty Sails Handicap has been