Portfolio comparison
John L. Mason vs ELECTRO STRING INSTR CORP
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
Company B
ELECTRO STRING INSTR CORP
Patents indexed
1
Year range
1937
Most recent
1937
consumer_electronicsmechanical
Top Patents1 enriched
US 2089171· 1937
How the Frying Pan Guitar Created the Electric Guitar
Activity by Decade
1930s1
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