Who is writing these four letters?

The author of the letters, Robert Walton, is a 28-year-old sea captain who is embarking on a journey to the North Pole region in order to find a passage from the Pacific to the Atlantic. He writes the letters to his sister, Mrs. Saville, in London, England. He has talked about making this expedition for six years‹it has been a favorite dream, and he is pleased that he finally has a chance to make good on his promise to himself. Other dreams, such as becoming a poet or a playwright, have not worked out. Therefore, this vision must succeed. The writer of letters is thrilled that he will satisfy an "ardent curiosity" by setting foot on a part of the world never visited by man.