Talk:19th Century glassmaking innovations in the United States

Lehr
A lehr is a long conveyer oven where glass is gradually cooled (annealed). The beginning of the lehr is hot, but the end is at room temperature. If glass is not annealed, it can easily break as portions of the glass cool at different rates. I have always been told that the term "lehr" comes from the German word for a teacher. An instructor/professor/teacher is called "der Lehrer". When the glass is placed on the conveyer, it is "taught" by the lehr to not easily break. Unfortunately, I have not been able to find a good source to cite this fact for the main article. TwoScars (talk) 15:26, 7 February 2024 (UTC)