Source: Rockford Morning Star and Rockford Register Republic “Centennial Plus 10” Special Edition, March 1962
Flue Stopper
J. L. Clark Celebrates 100 Years – 2004
Source: Rockford Register Star Nov. 8, 2004
Clark, John L. – Patent, 1905, Flue Stopper
Source: www.uspto.gov
Clark, John L. – Patent, 1900, Flue Stopper
Source: www.uspto.gov