Q. What is the origin of the term "glory hole"?

The origin of the term, in the context of glassblowing, remains unknown. Otto Hilbert, a Corning Glass Works historian, suggested that the term comes from the religious idea of “glory” – when you put glass into the glory hole you can imagine a halo effect. Our Hot Glass Demos FAQ on the subject provides a similar answer:

While there is no concrete answer, there are several plausible origins of this term. In an old factory, where smoke and dust were everywhere, a 2100° opening would have created an illusion not unlike that seen in paintings of saints and angels where 'The Glory' radiated from their heads. A break in the clouds where sunlight passes through is also called a glory hole.

At the same time, definition 9.c. of "glory" (noun) in the Oxford English Dictionary is simply

Any circle or ring of light; a halo, corona.

The term’s use is recorded in glassmaking texts by the mid-1800s. See, for instance, Apsley Pellatt, Curiosities of Glass Making: With Details of the Processes and Productions of Ancient and Modern Ornamental Glass Manufacture (London: David Bogue, 1849), p. 65:

The best arrangements for annealing may be foiled, should the Glassblower unnecessarily lose time after finishing the work; as the hotter the goods enter the arch, the better; on this account, the large goods receive a final reheating at the mouth of a pot heated by beech-wood, and called the Glory Hole. Successful annealing depends much upon the proper direction of the wind : the best aspect for this purpose is when it passes over the fuel of the lear toward the lear chimney, so that the hot air is always radiating in the downward current upon the goods.

The Oxford English Dictionary cites Pellatt's use of the term as well. We have been able to locate slightly earlier examples of the term's use in glassmaking. For instance, the New York Evening Post on October 22, 1835, advertised the sale of the New York Flint Glass Works, which included among other things, an "eight Pot Furnace, Glory Hole, Lear ... & c., all in excellent working order."

Comments? Suggestions?

Our staff will continue to look for the origins of this term and update you when we find anything new. We welcome comments that might point us toward a more precise answer!