Crown Glass

Glass in America was used for creating space and conquering the weather.  Glass went from prized artistic decoration - colorful, reflective and brilliant - to becoming a basic building material.  Most of the techniques came from the Old World, England and France.  These techniques, along with the American glassmakers' genius, made glass into a necessity for large numbers of people  and large purposes.  But economics came first.

The common way to make glass until the 19th century was a process called "crown glass" or "bulls eye glass" (antique window on right). The process was quite elaborate and required a team of 10 men and boys.  A globe of glass was blown by pipe, then rolled onto an iron table until it became a cone.  Then an iron rod was attached to the cone end opposite the pipe and the pipe was removed, leaving the hot glass open at one end.

Skill was required to then spin the cone and reheat it until it flatten out into a disk with the iron rod still attached at the center, or the "crown."   The spinning continued as the disk cooled and became stiff.  The disk was cut free from the iron rod and taken to the kiln for finishing.

These circular sheets were small and became even smaller when cut square.  The "crown" mark in the center was always there to tell how the pane was made.  The thickness was uneven due to it being blown glass - so the edges varied from thick to thin.  This process was prominent in America until 1830. 

Next time...1830 and beyond
_________________________
Today in Pioneer History:  On January 9, 1493, Christopher Columbus mistakes manatees for mermaids while sailing near the Dominican Republic.  He describes them as "not half as beautiful as they are painted."