Danny Dunn and the Weather Machine by Jay Williams, Raymond Abrashkin

wouldn’t be so bad, Joe,” said Irene. “Everybody’s hoping that it will rain.”
    â€œSure. Me, too. But not when I’m stumbling around outside that weather station. Suppose Mr. Elswing is in a murderous mood today? I remember a movie in which, whenever the weather changes and a storm is coming up, this fellow turns into a bat—”
    â€œOh, shut up, Joe!” Irene snapped.
    Joe looked surprised, but he shut up. They walked on in a rather moody silence, thinking about Mr. Elswing and wondering whether they’d find the missing nozzle, and oppressed in spite of themselves by the gray sky after so many weeks of sunshine.
    They came, at last, to the weather station and went quietly around to the side. “Here’s the rock where we set IT up,” said Danny. “But there’s no sign of the nozzle.”
    â€œAre you sure we lost it here, and not on the way home?” Joe asked. “You’d think it would be shining in the grass.”
    â€œI’m not sure of anything,” Danny replied. “Vanderbilt may have carried it off somewhere.”
    â€œMaybe he thought it was a bone, and buried it,” said Joe.
    â€œTell you what, Joe,” Danny said. “You go round to the other side and search, and begin working your way to the back of the building. Irene and I will search here. We’ll meet you in the rear. If we can’t find it, we’ll just have to backtrack.”
    â€œAll right,” Joe agreed. “Only let’s keep quiet so Mr. Elswing doesn’t hear us.”
    He left them, and Danny and Irene began combing the ground, moving slowly with bent heads, kicking aside tufts of grass and turning over stones.
    â€œI don’t know,” Danny said, after five minutes of this. “It’s like looking for a needle in a haystack. It could be anywhere. It’s just as likely to be a dozen yards away as right here.”
    As he said this, he kicked his foot against a stone. There was a clink ! The stone rolled away, and there lay the nozzle, its gray metal gleaming dully in the daylight.
    â€œOh, for goodness’ sake,” Irene exclaimed, laughing. “Wouldn’t you know it?” She picked it up.
    â€œSh!” Danny warned, involuntarily glancing at the station.
    And there stood Mr. Elswing in the window, with his hands in his pockets.
    â€œHello, kids,” he said cheerfully.
    Danny was opening his mouth to reply. Suddenly, Joe raced into sight around the edge of the building. “Run!” he screamed. “He’s after me!”
    Danny and Irene had been tense all morning. This was enough to set them off. Panic descended on them and, without thinking or waiting to ask any questions, they turned and fled.
    Across Washington Avenue they tore, heedless of the traffic. They ran through the university grounds, dodging students, and galloped into the woods. They crashed through underbrush and brambles, and finally emerged breathless at the edge of the Professor’s property.
    Danny threw himself on the ground. “I— don’t—care,” he gasped. “Let him—catch us. I can’t—run—any—more.”
    The other two fell at his side. After a moment or two, when they could breathe again, Danny asked, “By the way, Joe, who was chasing us?”
    â€œWhy, Mr. Elswing,” Joe panted. “I saw him through the window over on my side of the building. He yelled something at me, and started to climb through the window. So I ran.”
    Danny’s jaw dropped. “But he couldn’t have,” he said. “He was standing on our side, and he smiled and said hello as sweet as pie.”
    Joe scratched his head. “The pie over on my side was nothing but crust,” he said. “I’m sure I saw him.”
    â€œYou just thought you did,” Irene said.
    â€œMaybe it was a double exposure?” Joe suggested.
    â€œNo, you were thinking