Time-O-Stat, 8 Day Jeweled Thermostat

This Time-O-Stat 8-Day Thermostat was manufactured by the Time-O-Stat Controls Corporation of Elkhart, Indiana around 1932. The home owner could program thermostat to keep different temperatures during the day or night, and the clock switched between these temperatures for 8 days before it needed to be wound. The thermostat’s temperature could be set between 60 and 80, and the thermometer on the front displays the temperature from 30 to 100 degrees. This thermostat contained a mercury switch on a helical bi-metal coil, the mercury served to slow the opening and closing of the circuit that controlled the furnace, preventing “short-cycling.” Time-O-Stat was a large company that specialized in control systems that had applications in a variety of industrial, commercial, and domestic applications. Time-O-Stat was purchased by the Minneapolis-Honeywell Regulator Company in 1934, who continued to sell a Time-O-Stat brand thermostat in the years following the acquisition and used Time-O-Stat control patents in future devices.
The ubiquity of thermostats in 21st century homes shrouds the decades of innovation, industrial design, and engineering that went into making them an everyday object in almost every home. In the early 20th century, a majority of American households still heated their homes with manually operated furnaces that required a trip down to the basement and stoking the coal fired furnace. Albert Butz’s “damper-flapper” system was patented in 1886 and allowed user to set the thermostat to a certain temperature which would open a damper to the furnace, increasing the fire and heating the house. Progressive innovations allowed for the thermostats to use gas lines, incorporate electricity, turn on at a set time, include heating and cooling in one mechanism, and even connect to the internet.
overall: 6 7/8 in x 3 1/4 in x 3 1/8 in; 17.4625 cm x 8.255 cm x 7.9375 cm
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Work and Industry: Mechanical and Civil Engineering
Domestic Furnishings
Engineering, Building, and Architecture
Object Project
Exhibition Location
National Museum of American History
Data Source
National Museum of American History


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