"‘In the Primitive Church there was a godly discipline, that, at the beginning of Lent, such persons as stood convicted of notorious sin were put to open penance . . . until the said discipline may be restored again, which is much to be wished.’ – Introduction to the Commination.
Yet Church Discipline was, even throughout the eighteenth century, a much greater reality than at the present day. Excommunications and presentments were still in force, and the commutation of penance was a matter of grave and careful consideration even by so strong a Protestant as William III.
Wordsworth has told us that one of his earliest recollections (about 1777) was seeing a woman doing penance in a white sheet: this was called ‘solemn penance’" (Percy Dearmer's Parson's Handbook, emphasis mine).
Note: The Commination is a penetential service appointed for Ash Wednesday, to be found in the 1662 Book of Common Prayer.