Q: How do you get the glass into the furnace?
A:This particular furnace is filled by shoveling it in. Paper bags are filled with solid chunks of glass and then those bags are shoveled in one at a time. The furnace is over 2200 degrees so the paper bag instantly catches fire and burns away. The glass chunks melt into molten glass in a big pot inside the furnace.

Q: What kind of glass is it?
A: It is a glass that is specially formulated for glassblowing.