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"As the speed increases, and the link is 'notched up', the lead is increased as the cut—off is shortened, and at high speed we have a large lead. With the Gooch link, the lead can be set for average running speed, and although a little too great for good work at slow speed." —Derr, 1911

Steam Engine Gooch Link and Valve Gear Arrangement

"As the speed increases, and the link is 'notched up', the lead is increased as the cut—off is…