How Galileo thermometer works?
A Galileo thermometer is a sealed glass tube containing a clear liquid and five floating glass balls, each containing a different coloured solution. Attached to each ball is a metal disc stamped with the temperature. The temperature can be measured by reading the metal tag attached to the lowest floating balls in the top half of the thermometer. Galileo thermometers work on the principle of buoyancy, which determines whether objects float or sink. As the temperature changes, the glass balls will either sink to the bottom (temperature rises) or float to the top (temperature falls). At higher temperatures (greater than 26°C), all the balls will sink to the bottom of the cylinder. If the temperature drops below 18°C, then all the glass balls will be floating at the top of the thermometer, so the thermometer can only really be used indoors.
How Storm glass works?
Observing the liquid in the storm glass was supposed to indicate changes in the weather. If the liquid in the glass was clear, the weather would be bright and clear. If the liquid was cloudy, the weather would be cloudy as well, perhaps with precipitation. If there were small dots in the liquid, humid or foggy weather could be expected. A cloudy glass with small stars indicated thunderstorms. If the liquid contained small stars on sunny winter days, then snow was coming. If there were large flakes throughout the liquid, it would be overcast in temperate seasons or snowy in the winter. Crystals at the bottom indicated frost. Threads near the top meant it would be windy.
How sand pendulnum works
A simple pendulum can be described as a device where its point mass is attached to a light inextensible string or metal rod and suspended from a fixed support. The vertical line passing through the fixed support is the mean position of a simple pendulum. The vertical distance between the point of suspension and the centre of mass of the suspended body, when it is in the mean position, is called the length of the simple pendulum, denoted by L. This form of the pendulum is based on the resonant system having a single resonant frequency.
With the swinging of the pendulnum, it tells you that our earth is rotating.