A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Gary LaPook
Date: 2017 Jan 1, 23:30 -0800
From: Robin Stuart
Date: 2016 Dec 31, 12:43 -0800
The relevant text can be found here. Probably the key phrase is "this sphaerical superficies iIncreasing successively from the towards either pole, until it come to be of aequal diameter with the cylinder". I'll leave to you to decide whether this description is consistent with my interpretation.
I am attaching Edward Wright's own explanation, it starts at page 18 of the attached PDF.