Lighting, Heating, Air-conditioning
The earliest form of train lighting was provided by Colza oil lamps. The next stage was gas lighting, using compressed gas stored in cylinders under the coaches. Finally, electric lighting was introduced.
Early railway coaches had no heating but passengers could hire foot-warmers. These worked on the same principle a modern sodium acetate heating pads. Later, steam heating was introduced, using a steam supply from the steam locomotive. Steam heating continued into the diesel locomotive era, with steam supplied by a steam generator. Now, electric heating is almost universal and air-conditioning is often provided as well. In the case of diesel multiple units, the coaches may be heated by waste heat from the engines, as in an automobile.
Read more about this topic: Passenger Car (rail)