Varley made a number of these on-the-spot watercolours during his visits to Wales in 1803 and 1805. He had an overiding concern for accuracy in drawing landscapes; his use of optical devices and invention of the Graphic Telescope are well known. But he was also interested in capturing more ephemeral aspects of nature such as the effects of light and weather. These coloured sketches are his most poetic works, charged by the experience of the mountains. In 1803, Varley and Cristall remained on the summit of Cader Idris as night fell, surely set on testing the legend that those who slept on the grave of Idris descended from the mountain either a mad-man ... or a poet. It was Varley who sent Linnell a copy of Paley's Evidence of Christianity in 1811 (Cf. No.31).