The first Volcano was discovered in 79 A.D and was called Mount Vesuvius. It demolished the Roman Town of Pompeii and killed about 16,000+ people, they were suffocated from the ash from the eruption. Volcanoes are openings in the Earth’s surface. When they get active they let ash, gas and hot magma escape in violent and eruptions.
The thermometer was invented in 1593 by Galileo Galilei. They were used also for seeing how hot and how cold things were. For example, he would use it for weather, medicine, and scientific research just like the volcano. But if tested on things too hot, for example, lava was too hot, and lava was about 2,120 Degrees, the glass would burst. But now, today his invention is used for decorations.
Around 1821, a guy named Thomas Seebeck was the first to invent the Thermocouple. The thermocouple was to see precisely measure temperature. For instance, used for hot lava that was coming from the volcano eruption without it breaking. It was discovered in the 1800's. It was made of 2 different types of metals and made into an electrical source, Known as the "The Seebeck Effect". When electric currents passes through them, its connected to an Milivoltmeter and is converted into temperature reading.