Theo's Rain Gauge

The scissors caught on the plastic, then skidded. Theo cut the top off the bottle and turned it upside down. He set the cut-off piece inside the bottom half, like a funnel.

The kitchen table was covered with newspaper. Mom had insisted, because there was still a glue stain on the table from last month's homework. The bottle was a two-liter water bottle with a flat bottom. Theo had peeled off its label that afternoon. The sticky patch left behind clung to his fingers and kept lifting the corners of the newspaper.

The homework was simple: keep a weather log for one week. Ms. Hart had written it on the board today in big letters. Every pair would build its own station, write down what it measured each day, and tell the class about it next Friday. Theo didn't know yet who his partner would be. Ms. Hart was going to announce the pairs tomorrow.

The whole class had started talking at once. Somebody said they would make a weather vane, somebody else that they would bring a thermometer. Ms. Hart had put a photo of a real weather station up on the board. There were white posts, little spinning cups, and a metal bucket standing high above the ground. Theo had looked at that bucket most of all. It was called a rain gauge. All the way home, he had kept thinking about it.

Theo pressed the funnel down a little harder. The plastic crackled, then settled into place. The cut edge was sharp, and it lightly scratched the tip of his thumb. Mom turned the kettle down and came over. Together they wound paper tape around the cut edge, round and round.

"Now it looks less dangerous," said Mom.

"It looks less cool, too," said Theo.

Mom laughed and didn't say anything. In the kitchen, the smell of tea mixed with the sharp smell of plastic. Theo held the bottle in both hands and turned it around. The funnel wobbled a little, but it didn't fall out.

But Theo had one number in his head, much more than the homework. The weather app on the phone showed the coming week day by day. Monday had a little sun, Tuesday a cloud, Wednesday another cloud. But over Thursday sat a fat purple cloud. Under the cloud were three lightning bolts and, in big letters, "90%".

Theo pulled the screen down to refresh it. The number stayed the same. He refreshed it again, and again. On the third try it still hadn't changed.

"Ninety percent," he said out loud. "That's almost certain."

Dad called from the living room. "What's almost certain?"

"There's a storm on Thursday. My bottle is going to fill right up to the top."

Dad came to the kitchen door and pushed his glasses up onto his forehead. "That's a forecast for a whole week ahead. A lot of clouds will come and go before Thursday."

"But it says ninety percent."

"Ninety percent is a forecast," said Dad. "The sky doesn't read the app."

Theo shrugged. In his head, the presentation had already started. He was standing in front of the board, holding a bottle filled to the brim. The class had gone quiet. Someone in the back row was asking, "All that rain fell?" And Theo was nodding, like a serious scientist.

He lifted the bottle up to the kitchen light. The light passed through the plastic and threw a crumpled shadow onto the newspaper. The bottle was completely empty. That was fine. On Thursday it would fill.

But what if the storm knocked the bottle over? Theo thought about that too. He would put something heavy at the bottom. A stone, maybe, or a little bag of sand. He decided to solve that problem later.

He tapped Thursday in the app. An hour-by-hour list opened. The rain started at three in the afternoon and stopped at six in the evening. Next to the wind was a tiny arrow pointing east. Theo didn't look at the arrow. His eyes went back to the ninety percent.

There was a drawing on the back of the homework sheet. A cut bottle, an upside-down funnel, and a ruler standing straight beside them. Underneath, in Ms. Hart's round handwriting, were two lines.

"The top of the funnel should be the same width as the body of the bottle. Then the height of the water in the bottle will match the height of the rain that falls on the ground."

Theo read it twice. The first time, he didn't understand a thing. The second time, he put the sheet next to the bottle and studied the drawing.

He wondered what would happen if they weren't the same width. A wide funnel on a narrow bottle would catch a lot more drops. The water in the bottle would rise fast, even if the same rain was falling from the sky. Then the number would be lying. Theo laughed a little at the thought. Surely nobody would ever think of a trick like that. The funnel didn't make more water. It only gathered the falling drops inside and kept them from escaping. As long as the top and the body stayed the same width, one millimeter of rain would make one millimeter of water in the bottle. He looked at his own bottle. The funnel was the bottle's own top. The width matched.

He took the clear tape and his thirty-centimeter plastic ruler out of the drawer. There was an old ink stain on the ruler, right next to the fifteen. He stood the ruler up beside the bottle.

The end of the tape curled over once and stuck to itself. Theo tried to pick it apart with his fingernail, tore it, and started again. The second time it curled too. The third time it lay flat. This time he held the ruler perfectly still and wound the tape three times around the bottle.

He was holding the bottle up in the air while he taped. The ruler slid down a little and rustled softly under the tape. Theo checked whether the tape was lying flat. It was flat, and there were no bubbles.

When he set the bottle on the table, it tipped slightly to one side. Theo decided it was because of the thick tape. He tucked a folded napkin underneath, and the bottle stood up straight.

Now the numbers on the ruler climbed up the side of the bottle. One, two, three centimeters. Between each centimeter were ten thin lines. Theo bent down close to the lowest ones. One millimeter was almost nothing. It wasn't even as tall as an ant. He wondered how many of these little lines would be underwater on Thursday.

Then he put the bottle in the middle of the table and stood across from it. He folded his arms and looked at it like an engineer. It was a bit crooked and a bit crumpled. The paper tape on the cut edge had puffed up in one place. But it would hold water.

Still, he wanted to be sure. He filled a glass at the tap and poured it slowly into the funnel. The water swirled once around the funnel and trickled down through the narrow end. It gathered at the bottom and sloshed gently. Theo ran his finger all the way around the bottle. It wasn't leaking anywhere. The newspaper underneath stayed bone dry.

"It's waterproof," he told Dad.

Dad picked up the bottle, held it to the light and turned it from side to side. "Solid work," he said, and handed it back.

Theo emptied the water into the sink. He dried the inside of the bottle with a cloth, pushing the corner of the cloth into the narrow end of the funnel and twisting it twice. Then he opened his notebook. At the very top of the first page he wrote "Weather Log." Underneath he wrote his own name, and next to it he drew a line. The space on the line stayed empty. Tomorrow his partner's name would go there.

The notebook pages were squared. Theo counted the squares, then stopped counting. He would decide how to divide up the page once the station was set up.

They cleaned up the table. They folded the newspaper and put it in the recycling bin. The plastic scraps, the curly bits of label and the torn ends of tape all went along with it. The kitchen table was empty and shiny again. Only the bottle stood in the middle.

Mom bent down beside the bottle and looked at the ruler. She tapped the bottom end of the ruler, level with the napkin. "Zero is here," she said.

"Rulers start at zero," said Theo, laughing. Mom laughed too, and went to gather up the tea glasses.

Theo turned the bottle around once more. From the back, the numbers on the ruler looked backward, like writing in a mirror. He liked that. During the presentation, he would always hold the bottle this way round, with the numbers facing the class.

Before bed, Theo carried the bottle to his room. He put it on the shelf by the window, next to his books. He tucked the napkin under it again.

He looked out of the window. The sky was clear. Two stars showed above the roof of the building across the street, and a little farther off, the blinking light of a plane. The streetlight had painted the sidewalk yellow. There was no wind at all. The leaves of the tree on the sidewalk didn't stir.

Theo opened the window a crack. Cool air touched his face. There was no smell of wet earth, only car exhaust and the leftover smell of bread from the bakery. He closed the window again.

Theo checked the phone one more time. Thursday was still purple, still ninety percent. He switched off the screen, plugged the phone in to charge and turned it face down.

The bottle on the shelf gleamed faintly in the light of the streetlight. The tape on the cut edge of the funnel threw a small shadow onto the windowpane. He couldn't read the numbers on the ruler in the dark. Only the white lines showed faintly, like the steps of a ladder.

Theo pulled his blanket up to his chin. The dishwasher hummed in the kitchen, and from the living room came the sound of Dad turning the pages of his book. A door closed upstairs, and then everything went quiet. Tomorrow at school he would find out who his partner was. On Monday he would start measuring. And on Thursday, the bottle would fill.

He thought about his own station. At real stations, the bucket stood high above the ground, with no walls anywhere near it. Theo's home had no yard. But it had a balcony. One corner of the balcony was more open than the other side of the building. On Sunday he would take a look out there.

The room was cool. The radiators weren't on yet, because October had only just begun. Theo rubbed his feet together under the blanket and waited until they warmed up.

For a moment he imagined the bottle filling up. The water rose slowly, covering the lines on the ruler one by one. Then that thought slowed down too. Theo turned onto his side, facing the window, and let his breathing slow as he watched the thin shadow of the bottle.