Presentation 5: Inventions and Industry during the 18th Century

Daniel Gabriel Fahrenheit:

• He invented both the alcohol thermometer (1709) and the mercury thermometer (1714)
• The invention consisted of a glass tube with mercury inside, the temperature was able to be read by calibrated marks on the tube by the length of the mercury
• To increase the sensitivity of the thermometer, there is usually a "bulb" of mercury at the bottom of the tube, the top of the tube may be filled with nitrogen and is kept at a lower atmospheric pressure which is called the "vacuum"
• Mercury thermometers are still used today for meteorology purposes but have been banned in the medical feild and have been replaced by Galistan thermometers which is a liquid alloy of gallium, indium, and tin