West worked on the project for more than twenty years, producing eighteen completed paintings, nine oil sketches, and a number of drawings. The Ascension is a highly dramatic work, full of expression, emotion, and movement. West has tried to capture the spectacular, awe-inspiring sight of Christ rising to heaven upon a cloud. Beneath him, dumbfound figures watch the incredible scene in amazement. Because sketches such as this are not finished works, they are often characterized by a looser, more expressive handling of paint.
Many great artists do their best work in their sketches.
West himself may have been aware of this, for he submitted many of his own sketches for exhibition. He exhibited this particular work at the Royal Academy in 1801. The superiority of his sketches over his finished paintings was well-recognized at the time. I think he took too much pain with his sketches. The consequence was that the original spirit was lost long before the completion of the great painting, where his men and women too often look like wooden lay figures covered with drapery.