This is the very beginning of the under-drawing of a typical Dutch piece, a windmill viewed from a low angle in stormy weather. In fact the ground was put on largely with a typical burnt sienna wash thinned to transparency with solvent and which left the canvas quite orange. On top of that went some slightly less diluted paint just to mark out the space occupied by the mill and the deepest darks of the clouds.
At this stage it doesn’t look like a painting, just a set of splodgy marks. But it’s got the job done for today.