Short answers, pulled from the story.
Cylinder blown sheet glass is a type of hand-blown window glass made by blowing molten glass into a cylindrical shape, cutting off the ends, slicing down the side, and placing the cylinder in an oven where it unrolls into a flat sheet. It is similar to broad sheet but uses larger cylinders.
Blenko Glass Company used a process patented by William Blenko that employed molds around the cylinder to ensure consistent sizing. Unlike the standard method, Blenko intentionally preserved slight imperfections in the finished glass to give it the appearance of antique glass.
In 1839, the Chance Brothers invented the patent plate process. It involved placing a glass plate on a wet piece of leather, then grinding and polishing the surface to remove the damage caused by flattening and moving the cylinder during production.
Cylinder blown sheet glass was manufactured in the UK from the mid 19th century. Before domestic production began, Britain imported it from France and Germany, where it had been made since the 18th century.
In the early 20th century, hand-blown methods including cylinder blown sheet were replaced by machine manufacturing. Alternatives included rolled plate, machine drawn cylinder sheet, the Fourcault process, single and twin ground polished plate, and most commonly, float glass.
Broad sheet, blown plate, crown glass, and polished plate were all methods of producing hand-blown window glass that existed alongside cylinder blown sheet. These methods of manufacture lasted at least until the end of the 19th century.