Portfolio comparison
LaMarcus A. Thompson vs Theophilus Van Kannel
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 310966· 1885
Early Roller Coaster Design for Thrill Rides
Activity by Decade
1880s1
Top Patents1 enriched
US 387571· 1888
How the Revolving Door Was Invented
Activity by Decade
1880s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.