Portfolio comparison
John L. Mason vs EMI Ltd
Side-by-side portfolio analysis — patents indexed, year ranges, and activity timeline.
Top Patents1 enriched
US 22186· 1858
John Mason's 1858 Patent for the Mason Jar Lid
Activity by Decade
1850s1
Top Patents1 enriched
US 3778614· 1973
How Early CT Scans Created Detailed Body Images
Activity by Decade
1970s1
How to use
Bookmark a comparison URL to save it. Format: /compare/companies?a=[slug]&b=[slug]. Also see patent-level comparison.