active 19th century Harry Willson, The Use of a Box of Colours, in a Practical Demonstration on Composition…
“ Marking, with a stump and bit of black lead, when we are abroad, the principal points, in sketching from nature; and noticing in what manner those points refer to, and assist each other; tracing their effects, and ascertaining the laws that bring them harmoniously, or by contrast, together, is the best method to be pursued for the arrangement of our own ideas in composing. Sketches so obtained, should be preserved as models to exercise the invention by. ”
