1. A bell (old Saxon: bellan, to bawl or bellow) is a simple sound-making device. The bell is a percussion instrument and an idiophone. Its form is usually a hollow, cup-shaped acoustic resonator, which vibrates upon being struck. The striking implement can be a tongue suspended within the bell, known as a clapper, a separate mallet or hammer, or in small bells a small loose sphere enclosed within the body of the bell.
2. A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid (such as air or water) is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli’s principle and Newton’s third law. A propeller is often colloquially known as a screw.
3. A briquette (or briquet) is a block of flammable matter used as fuel to start and maintain a fire. Common types of briquettes are charcoal briquettes and biomass briquettes.
4. A fireplace is an architectural structure designed to contain a fire for heating, as well as for cooking. Fireplaces are also used for the relaxing ambiance they create. A fire is contained in a firebox or firepit; a chimney or other flue allows exhaust to escape.
Season 10 – Episode 10 – Bronze Bells, Wooden Air Propellers, Charcoal Briquettes, Log Fireplaces