Glory Hole

In glassblowing, the glory hole is a small, separately heated furnace opening a glassblower uses to reheat a piece of glass in between steps of shaping it on the blowpipe or punty, since molten glass cools and stiffens quickly and must be brought back to working temperature again and again during a single piece's making. It sits alongside the main furnace, where glass is first gathered molten onto the blowpipe, and the marver, the flat slab a glassblower rolls the hot glass against to cool its outer skin and true its shape; the glory hole is what lets a glassblower keep working a piece through many steps rather than finishing it in one continuous heat.