Translations
These corner frames were joined together from the bottom and tapered to meet at a single ring at the top—he made both corner frames this way.
They were paired from below, and together they were complete at the top at the single ring—so he made both, for the two corners.
And they were coupled beneath, and coupled together at the head thereof, to one ring: thus he did to both of them in both the corners.
coupled together from bottom to top and fitted into a single ring. He made both corners in this way.

