InfoSearch Read the passage. Ask two questions about the topic that answer from the information in the passage. Measuring Altitude A barometer called an al- timeter (al-TIM-uh-ter) can be used to measure altitude. At sea level, air pressure can hold up a 760-mm column of mercury. As you go higher, air pressure goes down. The mercury column drops. At 1000 meters above sea level, pressure will support a column of mercury only 710 mm high. At 5000 meters, the mercury column is about 420 mm high. Mount Everest is 8850 meters high. It is the highest point on the earth. Here the mercury column is only about 250 mm high SEARCH: Use library references to find answers to your questions.