The Carpenter’s New Guide - A Complete Book of Lines for Carpentry and Joinery, Treating Fully on Practical Geometry, Soffits, Groins, Niches, Roofs, and Domes, and Containing a Great Variety of Original Designs #227367

The next subject which regularly presents itself is Groins for the construction of which there will be found many methods entirely new; and besides the common figures, I have Shown many which are difficult of execution, and not to be found in any other author. I have displayed a variety of methods for constructing spherical niches, a form more frequently wanted than the elliptic, which only has yet been explained.