View this artwork by appointment, at Tate Britain's Prints and Drawings Rooms
Drawn with the sketchbook inverted. This very slight outline of the island on the horizon is taken from St Bees, which Turner visited in 1809. ‘White’ is presumably a reference to Whitehaven north of St Bees.
Turner’s inscription in ink reads:
Anaxagorus, A,,gar,tha,,chus | the sun 95 millions of miles distant | The Earth equal to 18 seconds of a degree | the 1200 seconds | the Moon nearly the apparent size of E.