Read the excerpt from "An Image of Africa: Racism in Conrad’s Heart of Darkness. ” But more important by far is the abundant testimony about Conrad's savages which we could gather if we were so inclined from other sources and which might lead us to think that these people must have had other occupations besides merging into the evil forest or materializing out of it simply to plague Marlow and his dispirited band. For as it happened, soon after Conrad had written his book an event of far greater consequence was taking place in the art world of Europe. This is how Frank Willett, a British art historian, describes it: Gauguin had gone to Tahiti, the most extravagant individual act of turning to a non-European culture in the decades immediately before and after 1900, when European artists were avid for new artistic experiences, but it was only about 1904–5 that African art began to make its distinctive impact. One piece is still identifiable; it is a mask that had been given to Maurice Vlaminck in 1905. He records that Derain was "speechless" and "stunned" when he saw it, bought it from Vlaminck and in turn showed it to Picasso and Matisse, who were also greatly affected by it. Ambroise Vollard then borrowed it and had it cast in bronze . . . The revolution of twentieth century art was under way! What type of evidence does Achebe use to contrast Conrad’s point of view with that of other renowned people of his era?