What Are Weather Instruments?

What Are Weather Instruments? — page 3
The thermometer is one of the oldest weather instruments still in use today It measures temperature or how hot or cold it is The first thermometer was invented by an Italian scientist named Galileo in about 1592 Many different types of thermometers have been developed since then The most basic type consists of a glass tube with liquid called mercury in it Mercury expands when it heats up and shrinks when it cools down These changes make the mercury level in the tube rise WHAT IS THE TEMPERATURE Galileo did much more than invent the thermometer He also used a telescope to make discoveries about space 6