Michael Mason (1941-2003) was a British literary scholar who taught English at University College London and later held a professorship there. His field was the long nineteenth century, from the Romantic poets to the Victorian novel. Plenty of people share his name, so it helps to know that this is the UCL academic and not a novelist or journalist.
He wrote as a cultural historian and editor. His best-known work is a two-part study published by Oxford University Press in 1994, The Making of Victorian Sexuality and The Making of Victorian Sexual Attitudes. Mason argued that the Victorians were less uniformly prudish than the stereotype suggests, and he built the case from medical texts, fiction, evangelical writing and radical thinkers. Not every reviewer was persuaded. Kirkus found the first volume dull and unconvincing, while Publishers Weekly described it as a dense, heavily footnoted treatise.
As an editor he produced the Longman edition of Wordsworth and Coleridge's Lyrical Ballads (1992), which gives the 1805 text of the collection and was reissued in 2007 with a new preface by John Mullan. For Penguin Classics he edited Charlotte Brontë's Jane Eyre (1996), adding an introduction that surveys how critics have read the novel, plus notes. He also reviewed for the London Review of Books.
Where to start? If you came here from Jane Eyre, the novel is Brontë's, and Mason's part is the apparatus around it: read the introduction after the story, once you have your own opinion of Rochester. To meet Mason in his own voice, begin with The Making of Victorian Sexuality, the volume on what people actually did and said, and keep the Attitudes book for later.