ON THIS DAY IN UNITED STATES HISTORY
March 25, 1902
The Sheet Glass Drawing Machine is Patented
On this day in 1902, Irving W. Colburn patented the Sheet Glass Drawing Machine, paving the way for the mass
production of window glass.
In the early 1800's before the Sheet Glass Drawing Machine, window glass which was in high demand was made by a
variety of different methods. One method was to start out by blowing a "bubble" of glass then spinning it
until it was flat. This method left a glass bump or "crown" in the center so it was called Crown Glass.
Another method was to start by blowing a cylinder. After it cooled, it was sliced down one side and
re-heated and spread out. By the mid 1800's a higher quality glass was produced by
pouring molten glass onto a plate. Once it cooled, it was polished on both sides.