'A New Augustus'

Here's the Coleridge Notebook entry Coburn numbers as 1:413:

Fluctibus extollens novum salutat Augustum
from the Album in the Brocken, a dante Hexameter—

It's something of a puzzle. The Latin means ‘Rising from the waves, he salutes the new Augustus’, and the rest of the entry can really only mean one thing: somebody had written the line down in a visitor's album in the inn at the Brocken, where Coleridge was staying in May 1799, as a curiosity, and Coleridge copied it into his notebook—the curiosity being that though this phrase occurs in a piece of Dantean prose it happens to be a Latin hexameter. It's the kind of thing that happens. Robert Graves used to go through the Times leaders underlining all the occasions when the prose slipped into iambic pentameter; he said sometimes the incidence was as high as 30%.

The problem is I can't find out where it originally came from. If it is an authentic piece of Dantean Latin, it must be about Henry VII of Luxembourg, whom Dante several times hailed as the new Augustus come to reunite Italy under a new holy Empire (he discusses Henry in these terms in the Monarchia, and wrote many letters on the topic: in Epistola 2.7.5 he even addresses Henry as ‘tu, Cesaris et Augusti successor’).

Henry crossed the Alps with his army in 1310, subdued most of Northern Italy, had himself crowned Emperor (the image at the head of this blogpost) and then, inconveniently for Dante's hopes, promptly died of malaria in 1313 at the age of forty. Several times in Purgatorio Henry is praised as the saviour come to redeem Italy and end secular control of the church, and in Paradiso 30:137 Dante sees the high seat of honour waiting for Henry in heaven: one who ‘came to reform Italy before she was ready for it’. So it's very possible that, at some point in his Latin prose, Dante imagines (let's say) Tiber rising from his bed to hail the new Augustus. But if he does so then I can't find it: it's not in the De Monarchia, and not in the Epistolae either. Maybe it's somewhere else? Or perhaps somebody wrote the phrase in the Brocken Album for some other reason and Coleridge jumped to conclusions. Hmm.