Spedding’s greatest challenge was how to get fresh air to the miners at the furthest coal faces.  Inland mines could dig ventilation shafts – clearly not an option for England’s first under-sea coal mine.

He used a combination of methods to get oxygen round Saltom.pit.  He called his methods “Air Coursing”.

Firstly he designed the mineshaft in an oval shape ten foot by eight foot . It was divided into two sections: One for 'drawing' the other for 'coursing' ventilation.   Fires were also lit at the base of the main shaft to speed up the flow of air.

As the workings extended Spedding installed a series of doors called traps.   By carefully controlling which doors were open and which were closed, he could force the air flow to reach the furthest coal faces.

The only problem was – when coal wagons went through the doors, someone had to close them again.  To an 18th Century businessman the answer was logical:   Small children, some as young as six, could be paid pennies a day to sit by the door and shut them behind the wagons.  These children were called “trappers”.

Today we would use automatic doors – but they didn’t exist then, and child labour was cheap and plentiful in towns like Whitehaven.