Well, that’s a good point. Yet another question comes to mind…Someone could say to us: “Since you don’t make a distinction between shorts and longs, go ahead use them as you like when singing, and in poetry…use stress”.
But in ancients who are supposed to build their metrics on this distinction one could say: Since you do that (build your meter according to this distinction), stick to that…
What a naive thought i’ve just made…but still a thought…
It’s not clear to me what point you’re making.
Nevermind, it was naive one way or another…
So, the point is that even there is a difference between long vowels and diphthongs (in duration), in metrics they are treated and pronounced in exactly the same lenght, isn’t it?
I would say “treated as though pronounced in exactly the same length.” The 10000s of lines of poetry make that clear. It’s possible that in recited (not sung) versions, the small variation could be accomodated without the need to stretch, but I don’t know that anyone has a solid way to resolve that question.
Just wanted to let you know, William, that I got a used copy of the 1982 (unabridged?) edition of M. L. West’s Greek Metre and have been thoroughly enjoying it. I already found the quote lying behind what you said about metra and cola, on p. 6:
In two of the commonest types of verse, the dactylic hexameter and the iambic trimeter, the regular caesura falls within a metron – an indication that here the analysis by metra does not reflect the real structure.
Although I detect at least two non sequiturs in that sentence (more about that later), I can tell that this is going to be a very valuable book. Thanks for the tip! 
You got it?! You have your own copy?! How on earth did you manage that? I’ve been trying to get my own copy for years.
Amazon.com marketplace. Someone was selling a used copy. Only one person, though, so I gather it’s not easy to find. I presume you know about Bookfinder?
Wow. I just spent some time looking into Dutch phonology, and learned about spelling Dutch along the way. Such passion for spelling reform!
I have heard that Dutch is the closest related language to English.
What a passion for languages.
Can you elaborate? (Unless you think the moderator will object to having a discussion about Dutch on this board.)
I think Friesian is closer. Of course not every one will consider it a language but I do.
Friesan is an official language in the Netherlands, but I don’t understand it. Are you a Dutch Canadian, Bert?
Just this: http://en.wikipedia.org/wiki/Dutch_spelling
Ah, you’re a language-nerd after my own heart, Billy Boy .