A reply to Mrs Clarkson’s report of criticism of The Excursion by Patty Smith, daughter of William Smith, M.P. for Norwich, to whom Mrs Clarkson had lent her copy of the poem (MY, ii. 184). The letter serves as a gloss on some of the more difficult ideas in the Essay, Supplementary to the Preface, written at about the same time. The manuscript of this letter is in Cornell University Library; my text is from MY, ii. 187–92.