Greetings, ones skilled in dialling,
Until the advent of the British Sundial Society the word dialist would hardly have been used at all in recent years in the UK so there is no great body of modern usage to settle the spelling. The Shorter Oxford Dictionary, which is something of an authority, gives the spelling as dialist, first citation in 1652, defined as a maker of dials; one skilled in dialling (so spelt). It does not allow diallist at all. Until recently the Bulletin of the British Sundial Society seemed to have had no settled policy but I believe has now settled on dialist. Does it matter? I myself prefer dialist but can usually interpret diallist after a moment's pause and without having to consult a dictionary. -- Frank Evans
