Portfolio comparison
Elias Howe vs William F. Semple
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 4750· 1846
How Elias Howe Invented the Modern Lockstitch Sewing Machine
Activity by Decade
1840s1
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.