The Distinction the South Had to Add

The Dravidian languages of the far south do contrast a short e with a long one, and Sanskrit and Prakrit do not, so the Brahmi received from the north was short of a sign the southern languages needed. Tamil-Brahmi handled the shortage in its own way, as it handled the sounds for which it added whole new letters at the end of the order, and the eventual southern solution was to mark the length distinction on the vowel rather than to leave it unwritten. That is a small adjustment beside the three additional consonant letters, but it is the same phenomenon: a writing system received for one language family being fitted to another.

The distinction matters for reading the inscriptions as well as for the history of the script. An orthography that does not mark a contrast the spoken language makes leaves a reader to supply it, and a reader who supplies it from Sanskrit will supply it wrongly. That is one of the standing difficulties of the earliest southern epigraphy, and it is part of why the Tamil-Brahmi material is treated as a distinct field with its own conventions rather than as a regional variant of the northern script. The mark for this vowel is written above the consonant sign, in the band the script keeps for the front vowels.