Scales Of Temperature

There are three main scales of temperature:

1. Centigrade or Celsius Scale
2. Kelvin Scale
3. Fahrenheit Scale

Conversion

Caloric theory
Up to nineteenth century it was believed a weightless fluid called caloric which existed in every material body. Caloric is a hypothetical weightless fluid. Every object contains a specific amount of caloric. Hot bodies contains more caloric than the cold bodies.
If caloric is added to a body, its temperature increases. When a body is broken, a large amount of caloric is released.

Failure of caloric theory
Caloric Theory has discarded now because it was unable to explain a number of thermodynamics process including production of heat by friction.