This drawing is from 'Fit the Fifth - The Beaver's Lesson.' In this chapter the Butcher identifies a scream as 'the voice of the Jubjub' and repeats himself three times thus proving it (it having been established by the Bellman that 'What I tell you three times is true'). The Beaver, though counting with scrupulous care, loses count after two, and the Butcher proceeds to give him a lesson:
'...Taking Three as the subject to reason about -
A convenient number to state -
We add Seven, and Ten, and then multiply out
By One Thousand diminished by Eight.
The result we proceed to divide, as you see,
By Nine Hundred and Ninety and Two:
Then subtract Seventeen, and the answer must be
Exactly and perfectly true...'
This then turns into a lesson on Natural History and the nature of the Jubjub bird, at the end of which the Beaver claims to have learned more in ten minutes than all books could have taught him in seventy years and the Butcher and Beaver become friends.
Peake studied the work of many artists looking for a suitable technique, including Hogarth, Cruickshank, Durer, Blake, Doré and Goya. His aim was to 'subordinate myself totally to the book, and slide into another man's soul'. His method with crosshatching often involved scraping back areas with a scalpel, which could cause problems when working on poor quality war-time paper.
PS. I've received an email telling me I've got my facts wrong about Peake's time in the war:
"Yes he started his military career at Dartford, but was moved to Blackpool in mid-October '40 and it was there that he received the contract for the Snark drawings, in Feb 1941.
Yes he was given work for six months in the Ministry of Information after his stay in the Southport hospital, but he was certainly not a "war artist" there. The work in the section he was in was essentially commercial in character and he was not suited to that. It was only after this that he was invalided out of the Army. And so forth."
Perhaps I should keep the biographical stuff to a minimum as there seems to be enough misinformation on the web already.