The mercury switch behaved kind of like the first hill of a roller coaster. It would linger at the edge of transition until it reached a breaking point then it

The mercury switch behaved kind of like the first hill of a roller coaster. It would linger at the edge of transition until it reached a breaking point then it would drop. Some modern thermostats try to emulate this behavior. The Honeywell T6 line of thermostats have technician settings for configuring this behavior though no technician takes the time to configure them for a home.