Portfolio comparison
William F. Semple vs Denka Co
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 98304· 1869
William Semple's 1869 Patent for Improved Chewing Gum
Activity by Decade
1860s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.