An unpublished letter in which a “despondent” Evelyn Waugh recounts how he burned his first attempt at a novel is to be auctioned this week.

Part of a set of 10 unpublished letters, mostly written to his friend Richard Plunket Greene, the missives date from a difficult period in Waugh’s life. The would-be author spent six months teaching at Welsh prep school Arnold House in 1925 and, while there, wrote to Plunket Greene about the lack of enjoyment he found in teaching the boys. “The older they are the more stupid I find them,” he wrote.

He sent the manuscript for his first novel, The Temple at Thatch, to the writer Harold Acton while he was teaching at Arnold House. Acton told him that the story was “too English for my exotic taste. Too much nid-nodding over port,” and recommended that Waugh print it “in a few elegant copies for the friends who love you such as myself”.

Facebook Twitter Pinterest Some of Waugh’s letters to Plunket Greene. Photograph: Sotheby's

In one of the letters, Waugh describes “feeling a little despondent” and reveals that he had burned the manuscript, adding: “It made so much smoke that the Headmaster [went] out of Chapel to see if his school was on fire.”

Not all is doom and gloom – at one point Waugh tells his friend that he won the masters’ egg-and-spoon race. But he also writes of how “five minutes ago I decided to accept the job at Pisa as secretary to Scott-Moncrieff … The only real regret I shall have will be leaving friends … for the most part England means only debt and drunkenness and disapproval.”

This job offer from Proust’s translator, however, would fall through, and together with the rejection of his writing, would plunge Waugh into despair. In his autobiography A Little Learning, Waugh writes of how it drove him to leave his clothes and a note from Euripides on the beach and swim out to sea. “As earnest of my intent I had brought no towel,” he writes in his memoir. “I cannot tell how much real despair and act of will, how much play-acting, prompted the excursion.” He was repeatedly stung by jellyfish, as it turned out, and returned to the shore.

According to Sotheby’s, which will auction the letters for an estimate of between £15,000 and £20,000, they provide “important clues about Waugh’s development as a writer, as well as revealing much detail about a key set of friendships, and his life in the school that was to provide the source of one of his most enduring fictions, Decline and Fall”.

In another letter, Waugh writes of his plans for a new novel after The Temple at Thatch was rejected. It would be, he writes, “a prose epic of Silenus … with all manner of roistering in public houses and brothels”. One character, he says, is “an unpleasing but accurate portrait of myself”, but he promises that no one else is taken from real life. In another, however, he refers to the teacher who would inspire Decline and Fall’s Captain Grimes: “Bathing has started to the intense excitement of the Sodomite master.”

The auction house said: “It is not a well-documented period in Waugh’s life, and the recipient of these revealing and often hilarious letters was, at the time, one of the author’s closest friends.”