Six's thermometer is used to measure

Six's thermometer is a type of thermometer that is commonly used to measure the minimum and maximum temperature of a particular location over a period of time. It consists of a U-shaped glass tube that is filled with a special liquid, usually mercury or alcohol, which expands and contracts as the temperature changes. The tube is attached to two separate scales, one on either side, which record the highest and lowest temperature reached during the period of observation. Thus, Six's thermometer provides a simple and reliable way to measure both the minimum and maximum temperature at a given location.