Turner used this sketchbook on his last trip to Switzerland. He began the book twice, at first making a group of three sky studies, including this one, most probably as he crossed the Channel. Then, once he had reached Lucerne, he painted his sketches of Mount Rigi at the other end of the book. The use of a simple combination of yellow and grey washes effectively recreates the light of dawn, at the moment before sunrise.
Gallery label, September 1995