Measuring the Speed of Light With a Toothed Wheel in Paris
Measuring the Speed of Light With a Toothed Wheel in Paris — a science story. 10 illustrated pages, narrated, on the kids shelf, free to read on Wonder Science.
Page 1
The wind came up off the river all at once, slapping through the vine rows and catching the telescope's tall wooden tripod broadside. Fizeau grabbed for it, but the gust was faster, and the legs buckled sideways into a row of vine stakes with a crack of splintering wood. The heavy glass lens popped free of its brass mount and dropped, bouncing once on the stony terrace before it began rolling, faster and faster, down toward the next low wall. Fizeau shouted and scrambled after it, boots slipping on loose earth, his scarlet cravat whipping behind him. Below, Colette heard the commotion and came pelting along the terrace, clogs clattering, flinging herself over a dry-stone wall just as the lens bounced toward the drop beyond it. She stretched her pinafore wide between both hands and skidded on her knees, catching the spinning glass with a soft thump against the yellow cloth. Lentille shot after it through the vines, skidding sideways in the dirt, and came to a stop pressed against Colette's side, tail lashing with the effort of the chase.
Page 2
Gustave Froment hunched over the spinning lathe, squinting through the brass loupe flipped down over one eye, filing teeth into the rim of a brass wheel no bigger than a dinner plate. Seven hundred and nineteen teeth already glinted along its edge. He drew the file across the last notch, blew away the brass dust, and lifted the wheel free with oily fingers. It slid against his leather apron, bounced off his round belly, and dropped. The wheel struck the floor on its rim and spun away, humming across the planks. "Catch it, catch it!" Froment bellowed, lunging with both arms and missing. Fizeau dove sideways past a hanging pendulum, scraping his sleeve on a gear-wheel, but the wheel ducked under his reaching hand. Colette scrambled off her stool, braids flying, and skidded on her clogs. Lentille shot after it, claws scrabbling on wood. The wheel struck the open doorframe and shot out into the street, still spinning, with all three chasing and the cat hot on its heels.
Page 3
The brass wheel shot out of the workshop door and found the slope of the Rue Mouffetard like it had been born for it. Down it hummed, past awnings and barrels, gathering speed on the wet cobbles. It clipped the side of an apple barrel standing hip-high by a stall, and the fruit burst free, bouncing and rolling in every direction across the market. Colette, who had been chasing a rolling apple of her own, spun round at the sound and flung herself after the wheel instead, clogs clattering on stone. She skidded sideways and slammed one wooden sole down just as the wheel veered under a cheese-stall table, its surface about waist-high to a grown man. Lentille pounced from a barrel top, all four white paws landing square on the rim to pin it fast. Fizeau arrived skidding to a stop, scarlet cravat flying. Behind them all, Froment came puffing downhill, his loupe still flipped down over one huge eye, waving his arms for them to hold it steady.
Page 4
The rutted lane up the Butte had swallowed carts before, but never one so heavily loaded. The handcart's wheel sank to its hub in mud, and before anyone could grab the handles the whole crate tipped sideways, the great mirror inside groaning in its wooden box. Colette shrieked and threw her small weight against the side, bracing with both clogs dug into the muck, while Lentille leapt clear onto a fence post, fur bristling. Froment heaved at the axle, puffing, his loupe swinging loose, but the wheel would not budge. Then a lanky boy in a soot-smudged cap came loping down from the windmills, swinging a long hooked pole. Without a word he jammed the brass hook under the axle and threw his whole long body against it, levering the cart up out of the mud with a wet sucking pop. Fizeau grabbed the crate before it could slide again, and together they shouldered it, step by step, up the wooden stairs cut into the hillside, goats bleating somewhere above them in the pasture.
Page 5
The attic lantern-room was barely tall enough for the big round mirror, its frame wider than a man's outstretched arms, and the four of them had to duck under the bare rafters just to reach the window. Froment braced the heavy glass against the sill while Fizeau turned the long brass screws, aiming it back across the rooftops toward distant Suresnes. Then the broken shutter banged open and a pigeon burst through in a clatter of wings, striking the mirror's edge and sending it tipping sideways. Colette flung herself forward, catching the great glass with both arms spread wide before it could slide from the frame. Tibo snatched his cap from his head and swatted the air, chasing the panicked bird in loops until it fled back out through the shutter gap. Lentille, startled off her perch, scrambled up a rafter and clung there, ears flat, tail puffed to twice its size, watching the chaos below with wide amber eyes.
Page 6
The handcart wheels screamed against wet stone as they rolled onto the Pont Neuf, the whole bridge slick with drizzle and the towers of Notre-Dame smudged grey behind them. Tibo hauled on the front rope while Colette braced her clogs on the slippery cobbles, pushing from the side so the crate would not slide sideways off the planks. Then the cart lurched, the crate shifted, and the tin can of lamp oil lashed to its corner toppled, glugging a dark slick straight down the stone steps toward the quai. Froment grabbed for it too late, his big hands skidding across the wet cobbles. Fizeau didn't hesitate — he tore his long scarlet cravat loose and dropped to his knees, mopping the oil in wide swipes before anyone could slip. Lentille hopped from step to step, sniffing the ruined silk with twitching whiskers. Together they lowered the crate down into the waiting rowing boat, ropes creaking, boots braced against the current tugging at the hull below.
Page 7
The rope ran from the turret beam, twice a person's height above the garden wall, down to the crate where the apparatus sat heavy as a loaded handcart. Gustave looped the pulley rope round his thick forearm and hauled, grunting, while Tibo braced his long legs against the espaliered pear trellis and pulled hand over hand. Colette scrambled up a stack of crates to guide the swinging crate with both arms, calling directions as it tilted. Suddenly the rope slipped a hand's breadth with a sharp squeal, the pulley shrieking against the beam, and the crate dropped a jolt before catching again. Lentille, who had been clinging to the rope for no sensible reason at all, scrabbled wildly with her white-socked paws to keep from sliding. Fizeau threw his whole weight onto the line beside Gustave, boots sliding on the damp grass, cravat whipping, and together all four of them hauled in one great heave until the crate thumped safely down onto the turret ledge, the stone sill barely wider than the crate itself.
Page 8
The toll bridge timbers knocked underfoot as Froment fed the iron surveyor's chain link by link along the railing, measuring the straight line toward distant Montmartre. Each link was the width of a man's palm, the whole chain longer than the bridge was wide, and it clanked like a dragged kettle. Fizeau called out the counted lengths while Colette marked tally strokes in chalk on a plank. Then a careless jerk sent one shining link sliding free over the mossy parapet, swinging toward the black water below. Froment lunged, whiskers flying, but his short arms missed. Tibo was already running, his hooked lamplighter's pole swinging up in both hands; he speared the dangling link clean and hauled it back over the rail with a grunt of triumph. Lentille, startled, scrambled up a mooring post as cold river fog rolled in, thick and grey, swallowing the barges first, then creeping up the slope until Montmartre's windmill vanished entirely into white. Everyone stood a moment, breath clouding, chain safe in hand, racing the fog before the distance was lost.
Page 9
The round cabinet was barely big enough for four bodies, but all four squeezed in anyway. Froment grabbed the falling weight and let it drop on its cord, and the brass toothed wheel screamed into a blur, its seven hundred teeth hissing like a kettle. Fizeau crouched at the eyepiece, hands steady, watching the tiny spark that had travelled all the way to Montmartre and back. At twelve and a half turns a second the spark vanished, snuffed out behind a tooth, swallowed clean. 'Gone!' Fizeau called, and Colette scrambled to the wall, chalk already scratching the number. Froment hauled the crank round harder, sweat shining on his bald head, muttonchops trembling, until the wheel doubled its speed to twenty-five turns. The spark blazed back through the next gap, bright as a struck match. Tibo whooped and slammed his lamplighter's pole against the floorboards in triumph. Lentille, perched on the limelight burner's crate, flattened her ears at the clatter but stayed put. The weight thumped down at last, cord spent, and Colette kept chalking numbers up the plaster as fast as her stubby fingers could move.
Page 10
Dawn broke pink over the river as the four of them climbed the wide stone steps of the Institut, each step as deep as Colette's whole leg, hauling the brass wheel between them wrapped in Fizeau's coat. Tibo set his lamp-pole down and grabbed one end of a long paper ribbon, running it flat down the steps while Froment pushed hard against the creaking spool twice the size of his arms, unrolling it further and further. Colette scrambled alongside on her knees, chalk squeaking, finishing the wobbly number she had begun in the night. A sudden gust snapped the ribbon up off the stone, scattering a flock of pigeons into the brightening sky, and Lentille leapt after the flapping paper, pinning its corner with both white paws just before it slid toward the water. Fizeau dropped to catch the other end, laughing, his scarlet cravat whipping sideways in the wind off the Seine, while Tibo ran down three steps to snatch the middle before it tore.
About this story
- Audience: kids (ages 6–12)
- Format: 10 illustrated pages, narrated, on the kids shelf, free to read on Wonder Science
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