Upright cylinders {churn}| can hold cream, and turning or raising and lowering a paddle makes butter or buttermilk.
A rough metal wheel scrapes against flint {cigarette lighter}|. The spark created lights lighter fluid or compressed butane. A glass fiber wick sucks lighter fluid. Compressed butane expands and vaporizes through tiny hole.
Draw curtains {curtain}| can use one string loop {drapery pull}. String lies in traverse rods. Loop attaches to right-hand curtain at top left and attaches to left-hand curtain at top right. Loop goes around pulley at curtain ends. Curtain hangs from holders in sliding rod. First holder pushes other holders back when curtain opens and spreads other holders out when curtain closes.
A forked stick {divining rod} can be for locating underground water sources.
Rulers {ferule} can strike children.
rocking horse {hobbyhorse}.
Braided necklaces {lanyard} can be for hanging a key or whistle.
Instruments {metronome}| can sound a frequency.
Babies can suck small rubber bulbs {pacifier}.
Razors {razor}| {straight razor} can have a blade with concave sides {hollow ground edge}. Leather straps {strop} can smooth edges. Razors {safety razor} can have plastic bars, which rest on face to prevent blade from gouging skin.
protective goggles {safety glasses}|.
Shoe-shaped inserts {shoetree} can stretch shoes.
Feathers {shoofly} can blow away flies.
A logarithmic scale on a moving piece can move past a logarithmic scale on a stationary piece {slide rule}|, to add exponents to perform multiplications or multiply exponents to raise numbers to power.
Metal cones {snuffer}| on rods can extinguish candles.
walking pole {staff, pole}.
Bottles {Thermos bottle}| can have two glass layers, with vacuum between. Glass layers have silvered surfaces facing each other, to reflect heat. Glass bottle attaches to container with rubber supports. Foam rubber, or plastic with many small compartments, is in ice buckets, refrigerators, and freezers.
Cylindrical cones {thimble}| can have textured tops and push needles through cloth.
Conveyor belts {treadmill}| can roll as people walk.
Metal forks {tuning fork}, with two long tines, can resonate at one frequency.
Devices {typewriter}| can print letters.
roller
A roller {platen} can rotate to move paper forward and back. Roller can slide back and forth, to allow typing anywhere on line.
process
When a key depresses, a lever moves type bar onto paper on platen. Shift key raises or lowers type bar to allow uppercase or lowercase letters to strike. Levers have angles so keys hit at same position. Depressing a key can rotate a wheel of raised letters into position for a hammer to strike from behind. Depressing a key can rotate a ball of raised letters into position for pressing against platen.
slide
When type bar, wheel, or ball returns to normal position, it hits a release lever that springs platen one space to right.
A movable plate can squeeze against a stationary plate {vise}|, to hold object.
Ridged boards {washboard}, can rub clothes when washing.
Slide fasteners {zipper}| [1890 to 1913] can have sliders that guide hooks into each other, at bottom. Slider top goes over zipper ribs, on hook outer edges, to line up hooks on inside.
Velcro uses two tapes {Velcro zipper}|. One tape has many small plastic hooks. The other tape has loops.
Anthracite coal subjected to high electric current makes soft carbon graphite. Graphite mixed with water and clay goes through holes in a steel plate. An oven dries and bakes the graphite rods. Machines apply wood covers {pencil, writing}|.
To sharpen pencils {pencil sharpener}|, hold pencil by hand or pincers in a tube. Handle goes to wheel with gear teeth inside and with tube to hold pencil. Two rollers are on opposite tube sides, in a V shape, with point at handle end. Rollers have gears that engage wheel. As handle turns, rollers and tube rotate. Helical edges on rollers peel off a thin wood layer.
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225