What is the function of Caroline Bingley's letter to Jane? Why has Austen utilized a letter to convey such info? What do its style, tone and contents reveal about the writer?

By informing the reader of Bingley's departure only through the letter of Caroline Bingley, Austen leaves many details up to the speculation of the reader. The description of Jane and Bingley at the Netherfield Ball leaves little room for doubt as to their mutual regard. It seems clear, therefore, that without outside persuasion he would not simply leave Netherfield with no intention of returning in the near future. According to the letter, Mr. Bingley himself had only planned to be away from Netherfield for a few days to attend to someone business. It seems that Caroline and her sister, and perhaps Mr. Darcy as well, plan to follow him and to persuade him not to return at all. This scheme seems particularly likely considering that Mr. Darcy had overheard Mrs. Bennet's jubilant conversation at dinner regarding what she considered to be the imminent engagement of Jane and Bingley. Knowing how much Mr. Darcy is concerned with social status, it is not unlikely that he would try to persuade Mr. Bingley not to propose to Jane.