Knowledge bank

The old people are living encyclopedia. My Dad was telling about the Bus which use to run on Coal.

It was the time before  second world war may be in 1940's,  petrol, diesel was acute shortage and during those days, the buses use to ply on Coal gas. The coal was burnt and the gas was used to run the bus.

I have tried to search about the same on  Internet  and  i  found this site.