Over the centuries-old history of its development, mankind has come up with many useful and necessary things. The inventors have made a lot of efforts to facilitate the life and work of a person. But one invention was particularly important and very timely. This is a thermometer invented about four centuries ago.
How to measure temperature?
Modern thermometers seem to be something familiar and commonplace. And few people think that until relatively recently, the temperature of objects around a person, water and air had to be determined only by sensations. A person could only tell if it was warm or cold today, but there was nothing to accurately determine the temperature.
The Middle Ages was the era when interest in science and accurate measurements appeared and increased. Mathematics, with its methods of quantitative assessment of phenomena, has firmly taken the position of the "queen of sciences". People have learned to quite accurately measure the volume and weight of various objects. And only the temperature was not measurable for a long time. And this is not surprising, because it is impossible to see or evaluate objectively this characteristic of material objects in the usual way.
Galileo's thermoscope
Fortune at the very end of the 16th century smiled at one of the greatest minds of his time, the Italian Galileo Galilei. He is widely known for his discoveries in the field of astronomy, as well as for the development and implementation of a number of very useful instruments. Galileo is also considered one of the founders of modern mechanics.
In the scientist's manuscripts, researchers found images of a device called a thermoscope, as well as a description of experiments carried out using this outlandish instrument at that time.
The prototype of the modern thermometer performed by Galileo was a ball made of glass, to which a glass tube was soldered. Carrying out his experiments, Galileo warmed a glass sphere with his hands, and then turned it over, immersing the free end of the tube in a container with a colored liquid.
When the ball cooled down a little, the volume of air in it became smaller. The air was replaced by a liquid that rose through a glass tube. In Galileo's thermoscope, the working agent was not mercury, but water. This design of the first thermometer made it possible to judge how hot a particular body was compared to another object.
But the accuracy of measurements was at that time rather low, since Galileo's device depended on atmospheric pressure.
Half a century later, other researchers and inventors significantly improved the first thermoscope by adding a scale to the device. If earlier it was possible to say about an object whether it is colder or hotter than another object, now it is possible to find out the degree of differences in temperature. Of course, the first instruments for measuring temperature were very imperfect and very different from those convenient and accurate devices that are widely used by mankind today.
