The names of the letters of the Latin alphabet
Two books and several articles have been written on this subject, and it is briefly discussed in some more general handbooks. The books are:
L. Strzelecki, De litterarum Romanarum nominibus: Bratislava, 1948;
A. E. Gordon, The Letter Names of the Latin Alphabet (U. Cal. Pubns: Classical Studies, vol. 9): Berkeley, 1973.
The latter is the fuller and more accessible work. I find myself in agreement with most of its findings, and here present only a summary of the arguments and most probable conclusions, in which I have drawn largely on Gordon's sources.
No particular problems are presented by the vowels. From the earliest sources onwards their names appear with the simple phonetic value of the letter, in its long form, i.e. ā, ē, ī, ō, ū. This is clear from their use in verse in Lucilius, e.g.
A primum est, hinc incipiam, et quae nomina ab hoc sunt,
where the hexameter requires that the first syllable be heavy, therefore ā Similarly in the sotadic lines of the grammarian Terentianus Maurus, e.g.
E quae sequitur vocula dissona est priori
and
nitamur ut U dicere, sic citetur artus.
The long vowel is also specified by the grammarian Pompeius in his Commentum Artis Donati (Keil, v, 101): ‘quando solae proferuntur, longae sunt semper’.
This practice is the opposite of what we find in India, where the short vowel was used to refer to each pair of short and long vowels: cf. Allen, Phonetics in Ancient India (O.U.P., 1953), p. 14.