Summer marks the period of Hornel's close collaboration with the painter George Henry (1858 - 1943). The purpose of their collaboration was to move away from the concerns of the Glasgow Boys and to explore ways to unite colour, form and theme in paintings with an almost poetic and musical effect. In Summer the explosion of colour and motion conveys the spirit and mood of the season. The lack or realism and the sharp contrast of colour caused the outcry from the City Council when P.H. Rathbone decided to buy the picture for the Walker. Hornel was only 28 year old when Summer was bought and the painting was the first ever work by the Glasgow Boys (apart from portraits) to enter a public collection. Rathbone's decision was based on the belief that it is a public art gallery's task to buy art apart from that which was established and easily understood by artists.