Both of the examples you cited are borrowed words. Because this sound
did not occur naturally in the intermedial position in Greek, the
"average" Greek would have probably had problems doing much more than a
glottal stop between vowels. If one *really* tried, he would have been
able to make a breathy fricative, an 'h'. It is not really strange that
this would be the case. I am sure you have heard the English of people
who grew up speaking another language. They "sound" foreign, and the
reason why they are identifiable is because the sounds they make follow
the patterns of those sounds in their native language. As far as being
enigmatic, would you also consider it enigmatic that English does *not*
have the "ng" sound at the beginning of words or the breathless
voiceless stop (like the 't' in stop) in a word initial position? These
are found regularly in other languages (Thai even makes a difference
between the breathy and non-breathy word initial voiceless stops [Thai
is pronounced like the English 'tie', Tai is pronounced like a Spanish
speaker would pronounce 'tie]), yet American English speakers have to
practice by the hour to develop the ability to quickly produce these
sounds in these situations.
> Does anyone have any light to shed on this?
> While I am at it, does anyone have any insight on the rationale behind the
> development of smooth breathing marks?
My guess is that they used a accent type mark because they considered it
to be part of the vowel characteristic, as opposed to a consonantal
characteristic as in English. They marked it because, in some cases, it
made the difference between two words which are otherwise spelled (and
sounded) exactly the same. These would be called "minimal pairs" in
Part of the joy of learning another language is recognizing the sound
structure of that language. We use our native language (I would guess
English, in your case) as a jumping off place, but we have to be willing
to greatly modify the "rules" that we learned to fit the cases found in
the other language.
Hope this helps,
Southern Methodist Missions