Photographed elsewhere on the site, this image represents the Ffestiniog Railway as it was in its early days.
The Ffestiniog Railway Company was founded by an Act of Parliament as long ago as 1832 but, the Railway itself wasn't completed until four years later in 1836, as a gravity-worked line carrying slate from the mines at Blaenau Ffestiniog to the harbour, at Porthmadog. The horses which, would each ride on a specially-built dandy wagon on the way down, at the back of each train one by one would pull the empty wagons all the way back. This was before locomotives were introduced to the Railway in 1863.
I hope the Ffestiniog & Welsh Highland Railways don't mind me uploading this.