Impossible

Have I - surely impossible - discovered a flaw in the scansion of, of all people, Hilaire Belloc?

That Night a Fire did break out--
You should have heard Matilda Shout!
You should have heard her Scream and Bawl,
And throw the window up and call
To People passing in the Street--
(The rapidly increasing Heat
Encouraging her to obtain
Their confidence) -- but all in vain!

The line "Encouraging her to obtain" only scans if 'Encouraging' is given its full four syllables, which is very difficult indeed to do; if you say it as the word is pronounced today there's an unpleasant dissonance.

It must have been sayable once, but I'm finding it hard to reconstruct just how.