In early April 1879, Vincent descended into the Marcasse coal mine and was given a tour by a man who had worked in the mines for 33 years. The experience made a powerful impression, as is evident from his evocative account in a letter afterward. After the terrifying descent down the mine shaft in a basket, a new world opened before him 700 metres underground:
“This mine has 5 levels, 3 of which, the uppermost ones, are exhausted and abandoned, one no longer works in them because there’s no more coal. If anyone were to try and make a painting of the maintenages, that would be something new and something unheard-of or rather never-before-seen. Imagine a series of cells in a rather narrow and low passageway, supported by rough timber-work. In each of the cells is a worker in a coarse linen suit, dingy and soiled as a chimney-sweep, chipping away at the coal by the dim light of a small lamp. In some of the cells the worker stands upright, in others (‘seams worked lying down’) he lies flat on the ground.
The arrangement is more or less like the cells in a beehive, or like a dark, sombre passageway in an underground prison, or like a series of small looms, or actually they look like a row of ovens such as one sees among the peasants, or like the separate tombs in a vault. The passageways themselves are like the large chimneys of the Brabant farmsteads.”
As a lay preacher, Vincent considered it important to understand what life was like for the labourers and to see a mine for himself: