In many parts of the country, days alternate being mild or freezing with no regard to the dates on the calendar. Polar vortex or balmy seems to depend on Mother Nature’s Mood. Before the days of the weather channel and 24/7 radar reports of fronts, thermometers helped people plan their days and their wardrobes. Many were decorative. All were helpful.
At the very beginning of the 17th century, those interested in scientific inquiry were experimenting with air and water to invent a method of measuring hot and cold. A “thermoscope,” predecessor to the thermometer, was developed which involved air inside a thin tube with one of its ends in a container of colored water. In 1610, Galileo tried it with wine and was credited with the first early alcohol thermometer, even though it was basically a thermoscope and didn’t have a scale. The first sealed liquid-in-glass thermometer was designed in Florence in the 1650s by Ferdinand II de’ Medici, Grand Duke of Tuscany. It used distilled alcohol, was unaffected by air pressure and had enameled measurement markings even though there was not yet an accurate scale.
In 1664 Englishman Robert Hooke was credited with the idea of using the freezing point of water as the starting point of a scale, experimenting with spirits and mercury. Sir Isaac Newton tried using linseed oil. Meanwhile in Copenhagen, Danish astronomer Ole Roemer chose ice and the boiling point of water as lower and upper limits for a thermometer that he used to record the weather. Then in 1724, a German instrument maker named Gabriel Fahrenheit settled on mercury as the most suitable liquid for measuring temperature. He also devised the first standard scale for measurement.
Thermometers with advertising first appeared in the 1900s and by the 1920s, were common. The earliest were made of metals like tin, plus wood. Thermometers made of tin or porcelain and decorated with product images or company names were popular with traveling salesman. They are popular now in home décor.