. > ...
the history of Leyton and Leytonstone
from . dot to … dots – with plenty of spaces
The Clean Air Act made smokeless fuel compulsory, but the real improvement to air quality came from replacement of coal fires, previously almost universal, with gas-fired central heating. Diesel trains replaced steam trains, though the conversion of the line to Liverpool Street into a branch of the electric underground had already occurred in 1947 1.
1 How the Railway Came to Leytonstone by Alan Simpson