Context: going back through the Epistles, vol. 1 to find points I overlooked the first time through.
Horace, Epistles, 1.1, ln 4
non eadem est aetas, non mens. Veianius armis
How I scanned it: DSSSDS
non ea/dem est ae/tas, non/mens Ve/ianius armis
eadem: at first I wanted to read eadem as the adverb, but Lewis and Short show this adverb to be pronounced eādem, and I couldn’t make this fit the meter. So I went back to the grammar tables, which reminded me that the nom. sing. fem. adjective eadem has no long a. So if I read eadem as adjective, nom. fem. sing., then I find an orthodox dactyl in the first syllable.
/dem est ae/: I elilded dem est to produce a single long syllable. I pronounce this d’mest, as if there were a consonant that started like d and then gave a light flick of the lips before pronouncing the vowel sound.