Drawing on evidence found in the Survey of English Dialects (SED), in Joseph Wright’s English Dialect Grammar (1905) and elsewhere, J. Lawrence Mitchell (1979) suggests that the development of Middle English [x] into [θ], [f], [s] and ø in such terms as trough, plough and sigh is the result of a systematic phonological process which he terms ‘sliding.’ This sliding, he maintains, takes place along a consonantal strength scale which determines the order of change as [x] → [θ] → [f] → [s]. The purpose of the present paper is to bring forward some evidence for. [f] → [θ], which runs counter to his theory.

In the Merriam-Webster file of transcriptions, which now numbers over 272,000 slips, attention was first drawn to the substitution of [θ] for [f] in 1955 by a citation for aphis consistently pronounced [eθis] by a resident of western Massachusetts. We also have the testimony of a college-educated native English speaker from eastern New England (Waltham, Mass.) that he grew up saying Philadel[θ]ia and epita[θ]. He reports, in addition, that this pronunciation of the Pennsylvania city was used by a college friend from northeastern New England, a usage which was the butt of remarks by other classmates.