In 1914, Van der Leck is commissioned by Müller & Co. to travel to the iron ore mines operated by the company in Spain and North Africa. In Algeria he makes a series of realistic sketches of the mining area, with rocks and a road or railway line on the left and right, and a bridge and crane in the middle.
After returning home, he makes four large studies in colour, in which he abstracts this landscape. In the last study, the bridge is reduced to a black horizontal bar and the road or railway line to two black diagonals that are aligned with each other. This drawing is the basis for the central panel of the triptych Composition 1916 no. 4.
The two side panels evoke an image of the pitch-black mine. With some effort, the summary, schematic representation of two mineworkers is discernible in these. The white block at the top might be the lamp in the mineshaft. He writes to Helene Kröller-Müller: ‘An enormous power prevails in the mines, there is something in them that is inescapable and that is the iron reality with no trace of romanticism’.