When Winnie-the-Pooh was published in the fall of 1926, it was an instant smash hit, selling 150,000 copies in time for Christmas and soon airing regularly on BBC radio. But in the months leading up to publication, its illustrator, E. H. Shepard , was still mulling over details, working out the shape of Piglet and the exact size of Pooh ’s stomach. This sketch work is on show in a pair of previously unseen drawings that have been brought forward by Shepard’s family on the centenary of the children’s classic. The two pencil drawings depict scenes from the original A.A. Milne book that ultimately remained unpictured and are on display at Peter Harrington Rare Books on Dover Street in London. E.H. Shepard, Climbing Very Cautiously Up the Stream (1926). Photo: courtesy Peter Harrington Rare Books. The first drawing, titled “Climbing very cautiously up the stream”, shows an intrepid Christopher Robin leading the way followed by Pooh, Piglet, and Owl .…