The painting in the Tate has been analysed to find that the bright yellow is due to the element sulphur whilst the ground for the painting is based on gypsum rather than chalk and that has led some to speculate that this was painted in Italy. It is not uncommon for Wright to arrange his compositions. The Tate painting does show the view to be between Sorrento and the Island of Capri, but from the walk up to Vesuvius you cannot see the two islands of Procida and Ischia which are included. Surprisingly it appears that Wright at the time Wright was in Italy Vesuvius was not erupting, but he may have seen something that was briefly as impressive.