Uploaded February 2026 | Updated September 2026, 2 hours ago

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Let's delve into the (not at all) dark story behind the switch that once existed in every home in America.
I found some mercury switches that must have missed a few steps during the manufacturing process, which led me to research the history and lore of the mercury switch.

#companyhistory #tools #diy #vintageelectronics

Check out the full Tool Lore playlist here: youtube.com/playlist?list=PL-fhNrtmTAv286gDzTcav8FyxCagDTouy

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Sources:
1905 Clark patent: patents.google.com/patent/US783612A
1922 Phelan patent: patents.google.com/patent/US1598874A
1937 Olson Patent: patents.google.com/patent/US2232626A
1953 Kronmiller Patent: patents.google.com/patent/US2729719A

Chapters:
00:00 Intro
00:36 WTF is Mercury?
01:15 Percy Clark's Switch
02:35 Louis Phelan's Switch
03:10 "The Round" Thermostat
04:00 Harold Olson's Switch
04:29 Pondering my Switches
05:04 Mercury Today