Portfolio comparison
Marvin C. Stone vs John Harvey Kellogg
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 375962· 1888
How the Modern Paper Drinking Straw Was Invented
Activity by Decade
1880s1
Top Patents1 enriched
US 558393· 1896
How John Harvey Kellogg Invented Flaked Breakfast Cereals
Activity by Decade
1890s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.