4 TALKING ABOUT THE WEATHER The weather is one of the most common topics of conversation Most people make casual remarks about the weather and that is enough for most of us However meteorologists scientists who study the weather want to know precisely how hot it is how much it is raining and from what direction the wind is blowing Is it really freezing or is it just very cold Meteorologists use many instruments to Feeling a drop is enough to know that it is raining But to find out how much rain there is you will need to use weather instruments
5 answer these questions After learning about weather instruments you can describe the weather just like a meteorologist This meteorologist uses a weather instrument called an anemometer to measure the speed of the wind Meteorology is the study of daily changes in weather in a particular place Climatology is the study of the average weather conditions over long periods of time all over Earth How are weather and climate similar How are they different COMPARE AND CONTRAST
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
7 and fall Markings on the outside of the tube show the degrees on a temperature scale There are several different scales that measure temperature The two most common are Fahrenheit and Celsius The Fahrenheit scale is used in the United States for everyday measurements On this scale the freezing point of water is 32 degrees and the boiling point is 212 degrees The Celsius scale is used for scientific work and everyday weather measurements in much of the rest of the world On this scale the freezing point of water is 0 degrees and the boiling point is 100 degrees Mercury is a metal that is liquid at ordinary temperatures Cold You can use a thermometer to tell when it is literally freezing
