Turner's 'Windmill and Lock' in the collection of Sir Frederick Cook at Richmond is clearly based on a close study of Rembrandt's 'Mill.' Pages 17 and 19 of the 'Greenwich' Sketch-Book contain the following 'halting in expression' notes:—
'... Rembrandt is a strong instance of caution as to reflected light and Correggio (?) to refracted light. Two instances of the strongest class may be found in the celebrated pictures of the Mill and La Notte. The Mill has but one light, that is to say, upon the mill, for the sky altho' a greater body or mass if reduced to black and white yet is not perceptible of sun's ray by any indication of form, but rather a glow of approaching light, but the sails of the mill are loaded with the ... ray, while all below is lost in ... gloom without the value of Reflected light which even the sky commands, and the ray upon the mill insists upon, while the 1/2 gleam upon the water admits the reflection of the sky. Ev ... twilight is all reflection but in Rembrandt it is all darkness and gleam of light, etc'.
I turn with relief from Turner on Perspective and Reflected Light to the thought of his pretty country retreat at West End, Upper Mall, Hammersmith, whither he went, it is said, to be near de Loutherbourg, 'whose imaginative genius he much admired.'
'A friend' communicated to Thornbury the following glimpse of the life at Hammersmith:—
'The garden, which ran down to the river, terminated in a summer-house; and here, out in the open air, were painted some of his best pictures. It was there that my father, who then resided at Kew, became first acquainted with him; and expressing his surprise that Turner could paint under such circumstances, he remarked that lights and room were absurdities, and that a picture could be painted anywhere. His eyes were remarkably strong. He would throw down his water-colour drawings on the floor of the summer-house, requesting my father not to touch them, as he could see them there, and they would be drying at the same time.'
In that happy mood no doubt he painted the seventeen 'beginnings' of pictures, exhibited for the first time in 1910 in Room XI. of the new Turner Gallery—large beginnings of riparian and rural scenes, free and decorative, that he no doubt exhibited in his own studio, inviting patrons to commission 'finished' pictures from these delightful suggestions.
He spent happy days making them, and in the garden at Hammersmith, but it is probable that the important event of 1808 to Turner, ever ambitious, ever reaching forward, ever clutching at fame, was the privilege of writing the letters P.P. after his name.