Portfolio comparison
William F. Semple vs Hymen L. Lipman
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
Top Patents1 enriched
US 19783· 1858
How the Pencil and Eraser Became One Tool
Activity by Decade
1850s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.