Hobbies And Interests
Mercury Barometer
Invented in 1643 by Torricelli, the mercury barometer functions using an upright glass tube that contains a column of mercury. The top end of this tube stays sealed, and the other end sits in a small bowl of mercury known as the cistern. When a storm approaches, the atmospheric pressure drops. This causes the mercury column in the glass tube to fall as well. Once the storm begins to pass, the atmospheric pressure rises along with the mercury. When using a mercury barometer, be aware that mercury is toxic. In the event that the barometer breaks, don't touch the mercury. Children should be supervised with handling a mercury barometer.
Water-Based Barometer
Like the mercury barometer, the water-based barometer employs fluid to record the changes in atmospheric pressure. This barometer consists of closed glass column. Water fills half the column. Below the water level, a thin spout connects to the glass container on an angle so the top of the spouts rests above the water level in the column. The water in the spout gradually rises above the water level of the glass column when the atmospheric pressure drops, signaling an incoming storm. When the atmospheric pressure rises and the storm moves away, the liquid in the spout falls.
Aneroid Barometer
The aneroid barometer relies on mechanics instead of fluid to measure the changes in atmospheric pressure. This barometer consists of two main components: an aneroid capsule and a face. Usually made out of beryllium and copper alloy, the aneroid capsule is a small, pliant metal box. Manufactures suck the air out of the box and carefully seal it. This allows the box to respond to variations in the atmospheric pressure by expanding or contracting. Levers and other devices translate the expansions and contractions of the aneroid capsule into readings on the face of the barometer.