Water thermometer

Invented by : Galileo Galilei

Invented in year : 1593

A Water Thermometer is one which is filled with water instead of mercury, for ascertaining the precise temperature at which water attains its maximum density. This is about 39 (deg) Fahr., or 4(deg) Centigrade and from that point down to 32 (deg) Fahr., or 0(deg) Centigrade, or the freezing point, it expands. The most common use of a water thermometer today is testing the temperature of water in the home. One practical application is especially important for new parents as they use it to test the temperature of bath water to ensure that an infant is not accidentally subjected to a scalding bath. Along with checking the bath water, the thermometer can also be used to maintain a check on the temperature of the water in the household water heater.

History of the Invention

The first Water Thermometer was created during the 16th century. In the year 1593, Galileo Galilei made a better Thermometer which was basically a water thermometer. This newer version was the first type of thermometer to allow variations in temperature. Galileo found that, if he used liquid that was less dense than water, he could suspend those liquids in a vial of water, which would rise as the temperature increased. Galileo was able to take the information he discovered and developed a model of a thermoscope (earlier name of Thermometer) that used fine droplets of alcohol. These droplets maintained their cohesion in the water and would rise to the top as the temperature of the water slowly increased.

Development in the Invention of Water Thermometer

• Santorio Santorio who put a numerical scale on the instrument in 1612.

• Mercury was later substituted for the alcohol, and then Daniel Gabriel Fahrenheit (1686-1736), a German physicist, used mercury plus a chemical solution that kept the mercury from sticking to the tube of the thermometer in 1714.

• In 1724 Fahrenheit also expanded the thermometer's scale, on his scale, the temperature of boiling water is 212°F and the freezing point of water is 32°F.

Role of Water Thermometer in the development of Human Life

• Persons who enjoy fishing may also find a water thermometer useful. By checking on the temperature of the lake or river, it is possible to determine what type of fish could be biting. Since some fish are more active at different temperature levels, this information can be the difference between a successful trip and an empty cooler.

• Teachers often use a water thermometer to teach students about the process of water expansion versus mercury expansion, noting that the two substances tend to react differently upon reaching the point of 39.2 degrees Fahrenheit. As the students grasp the expansion process as it relates to different liquids, the teacher can then employ the principle in different scenarios. From this perspective, the water thermometer continues to be an important teaching tool.

• It lead to the invention of other types of thermometers which were used for various purposes.