The first sketch in charcoal was probably done with the aid of a perspective frame which he mentioned in an early letter Arles, justifying its use by maintaining that earlier masters had employed it. This device had very important for Van Gogh from the beginning of his career.
I think you can imagine how delightful it is, he wrote enthusiastically to his brother in 1882 about the first perspective frame he owned.
To turn this spy-hole frame on the sea, on the green meadows, or on the snowy fields in winter, or on the fantastic network of thin and thick branches and trunks in autumn or on stormy day.
Long and continuous practice with it enables one to draw quick as lightning - and, once the drawing is done firmly, to paint quick as lightning too.
One of the most fascinating aspects of the The Real Van Gogh - the Artist and his Letters is the letter which illustrates the perspective tool which Van Gogh used and a sketch of him using it!
> Read more ... A sketch by Van Gogh using the perspective frame (Letter 253)
> Read more ... A little scratch of that perspective frame (Letter 254)