"But why in the world should a hail-stone be made like an onion?" said Fred, with a puzzled stare. "Isn't hail just frozen rain?"
"No," answered the Forecaster, "frozen rain is sleet, which is never seen in summer. It is caused by the rain in the upper air falling through a cold layer of surface air and becoming frozen on the way. Sleet is ice, and transparent.
"Hail never falls in winter, only in summer, and almost always in connection with a thunderstorm. It is made by drops of moisture, like very fine rain, being carried by the strong upward currents of a thunderstorm to altitudes where the air is very cold, there becoming coated with a layer of snow, and becoming heavier, falling through the less active upward currents on the edge of a storm. As these snow-covered frozen raindrops fall through the clouds, they grow bigger, because on their cold snow surfaces the moisture condenses and is frozen to a skin of ice. At the base of the cloud, they are often sucked in by the upward current and carried up again for another layer of snow, falling again through the clouds and being covered with another skin of ice. This may happen a dozen or a hundred times, the hailstones growing in size with every successive layer of snow and ice, until at last they become so heavy that they can no longer be carried up by the ascending currents, and fall to the ground."
"No wonder hailstones sometimes get so big!" exclaimed Fred. "I've seen them as big as pigeon's eggs. I never could understand it."
"I've seen hailstones that weighed more than half a pound," the Forecaster answered. "Not so very long ago, two ranchers and six hundred head of cattle were killed by hail in one Texas storm. Not a single animal was left alive. The loss from hail in our Western states is so large that most of the progressive farmers pay heavy hail insurance. Jagged bits of hail the size of a child's fist are not at all uncommon. If I'm not mistaken," he continued, "we may have some hail this afternoon, but nothing like that. This county isn't in the regular hail-belt."
During the description of the storm, Tom had been reeling in his kite and after the week's observations had been duly made and recorded, the boys prepared to scatter. Before they left, the Forecaster turned to them, his hand on Anton's shoulder.
"I think you boys ought to know," he said, "that I received a letter the other day from the Chief of the Weather Bureau. He's going down to New Orleans next month, and has promised to drop off here and spend the night with me. We were chums at college. He ought to meet the Mississippi League of the Weather."
An excited cheer went up from the boys.
"And what's more," the Forecaster went on, "I can tell you this—that just as soon as Anton is old enough, there will be a place waiting for him in the Bureau. He knows almost enough now to pass the Civil Service Exam, and in a couple of years he'll be as well equipped to enter the Service as any of the boys that are going in. I miss my guess if we don't find out, some day, that Issaquena County has given to the United States one of the best meteorologists of the next generation."
"Three cheers for Anton!" shouted Fred.