California Powder Works, Colorado Agency. Blue & flesh color design on 1904 cover showing "Hercules" with Club & Lion's Head, franked with 1903 2¢ tied by Denver machine cancel, Extremely Fine, a rare design (which is not to be confused with the Hercules Powder Co.), not included in the Biddle or Beals collections. Estimate  $150 - 200. $0 (Image)