Keith Koontz, age 10, of Richmond, Virginia, for his question:

How much water does Old Faithful erupt?

Each time Old Faithful erupts, it shoots about 10,000 gallons of water as high as 120 to 170 feet. The temperature of the water is around 200 degrees Fahrenheit and it rises in a steamy white fountain. The famous geyser is not the largest one in Yellowstone National Park. Several others spurt more water in higher fountains. But they erupt now and then, usually when nobody expects them.

Old Faithful earned its name because it erupts on schedule, though it may be a few little minutes early or late. Since 1870, when explorers first discovered it, the famous old geyser has been putting on its frothy display on an average of once in every 65 minutes. This goes on day and night, through spring and summer, fall and winter. Old Faithful is just about the most dependable geyser in the whole world.