According to North-East History Tour, Nicholas expressed a wish to visit a coal mine:
Arriving at Wallsend on 16th December 1816, he was given a prolonged tour of the colliery site, before being invited to change out of his glittering finery and into a deputy-overman’s outfit, prior to being escorted to the gaping hole that was the pit-head.
The chosen mode of descent for The Grand Duke was considered the safest of its day. This involved the riding of a large iron hook at the end of a long rope, by which he was told to cling to firmly, whilst keeping himself clear of the black and dripping walls with a short stick during his long, slow drop.
At the time, Wallsend Colliery was one of the most profitable in the land and produced the very finest quality coal. The visit was meant to impress and enlighten, but ended up delivering a little too much in the way of information. For when Nicholas was brought to the very edge of the pit and looked down into the abyss, he stepped back hurriedly, holding up his hands in horror, exclaiming in French, “Ah! My God! It is the mouth of hell! None but a madman would venture into it!”While I was at Segedunum museum, which stands next to the site of the old Wallsend colliery, there was an exhibition that took its name from this incident. "Into the Mouth of Hell" marked four major mining disasters that took place on Tyneside between 1812 and 1862. In particular, it commemorated the 150th anniversary of the Hartley Colliery Disaster, in which 220 men and boys died.
The fullest description of this incident and the community in which it took place is to be found on the Northumberland and Durham Family History Society site:
No man knew the people of these single-storey rows better than the colliery viewer, Joseph Humble. The viewer's duties were those of a manager who would be responsible for the day-to-day running of the pit, hiring workers, and so on. It was fitting that he had been chosen as census enumerator for much of the area in 1861: he would have known many of the families personally and would have their confidence in recording their details. Incidentally we have been able to find a good number of the miners' families in the 1861 census, but by no means all. Many would have moved into the area at the annual spring hiring in May, and in particular there was a big influx of new families from Scotland up at Quarry Row.
Joseph Humble played a vital role during the anxious days following the closing of the shaft. He it was that kept communications going between the rescuers, led by the renowned 'sinker', William Coulson, and the anxious families at the pithead. He it was that was asked to go down once the way was open and see for himself the huddled rows of bodies with sons cradled for protection in their fathers' arms.
His words poignantly expressed the grief sensed by all around him: "Oh, my men, my canny men, they would have done ought for me and there they are all lying dead and cold".The exhibition has now closed, but at South Shields Art Gallery you may be able to see John Robson's 1930 painting "The Hartley Men", which makes the disaster look like an outing from a progressive school of the period gone horribly wrong.