I have just got hold of a copy of the book in the picture, thanks to JDL. It’s the only book I know which does more than mention the pronunciation of the odd Cornish place-name. I don’t know why the authors of the various other books that I have on the topic seem to think that the pronunciation of names in Cornwall is self-evident. It clearly ISN’T.
June Lander, who died fairly recently, wasn’t a professional linguist. She had a long career as a journalist working on various local newspapers. On her retirement she came down here to live in Cornwall and wrote about the county. Another book of hers deals with Cornish eccentrics. Although her little book is by no means academic in tone or in style, I think she did a very good job. It must have been a lot of hard work.
As you might expect, she uses re-spelling to indicate the pron. of the names she lists. It’s a shame she didn’t set out a consistent and well thought out scheme for doing this before she started. There are occasions when the pronunciation she gives is ambiguous unless you happen to know how she represented some of the sounds in other names. For example, the name Kelynack gets the re-spelling K’LINeck. Now does that mean ˈlaɪn or ˈlɪn for the second syllable? People around here say it with the diphthong, I think*. Also she frequently has to resort to explaining her re-spelling. For example, Crowlas is re-spelled CROW-luss, but she has to add the note: ow as in now
These minor annoyances aside, the book is very useful. I have yet to find a name whose pronunciation I know where June Lander gives something different. She is also canny enough to recognise that pronunciations change over time and that there will always be disagreements as to the “correct” pronunciations of some names.
So now I can answer Jack Windsor Lewis’s question about the pron. of the name Polyphant. June Lander says it’s pəˈlɪfənt.
* The BBC Pronouncing Dictionary of British Names (ed. Pointon, G., 2nd ed., 1983) gives keˈlaɪnək and ˈklaɪnək for this name. Unfortunately it doesn’t list Polyphant.