This painting is one of a series of works that were partly inspired by Lanyon's experience of gliding. Lanyon began gliding in 1959 and the sensation of flight added new dimensions to his landscape painting. He gained a much stronger feeling for the elements. He later explained: 'The air is a very definite world of activity as complex and demanding as the sea.. The thermal itself is a current of hot air rising and eventually condensing into cloud. It is invisible and can only be apprehended by an instrument such as a glider.. The basic source of all soaring flight is the thermal'.