A maximum-minimum thermometer works by registering the maximum and minimum temperatures over a certain time period by using two scales set in liquid mercury. Two bulbs filled with alcohol or oil regulate the movement of the mercury. Maximum-minimum thermometers are typically U-shaped parallel tubes of glass. One side registers the minimum temperature, while the other registers the maximum temperature since its last reading. The bend at the bottom of the thermometer contains the liquid mercury, which moves up and down based on contractions of the oil or alcohol located in the two bulbs at the top of the thermometer. The contractions of the alcohol or oil are the result of thermal changes in the environment causing it to expand or contract.

·  Celluloid Graduated Magnet

·  Mercury

A maximum-minimum thermometer works by registering the maximum and minimum temperatures over a certain time period by using two scales set in liquid mercury. Two bulbs filled with alcohol or oil regulate the movement of the mercury. Maximum-minimum thermometers are typically U-shaped parallel tubes of glass. One side registers the minimum temperature, while the other registers the maximum temperature since its last reading. The bend at the bottom of the thermometer contains the liquid mercury, which moves up and down based on contractions of the oil or alcohol located in the two bulbs at the top of the thermometer. The contractions of the alcohol or oil are the result of thermal changes in the environment causing it to expand or contract.

·  Celluloid Graduated Magnet

·  Mercury