Adrodd fel Amhriodol
Testun Gwreiddiol (Anodiad: EAW044750 / 1369919)
'
These look like gas holders. In the earliest days of the Met, the carriages were lit by coal gas, which was stored (somewhat hazardously one supposes) in large rubberised bags located in the roof area of the carriages.
However, this method of lighting would have been abandoned in about 1905 when the Met was mostly electrified. Coal gas might well have been a by-product of the coal-fired electrical generation that took place at Neasden, but I am not clear what it would have been used for at this date. '