From Nicholas Carr’s “(re)framed” (Rough Type: 3 June 2011):
I’m reminded of an interesting passage in the book Glass: A World History:
As we have seen, one of the rapid developments in glass technology was the making of panes of window glass, plain and coloured, which was particularly noticeable in the northern half of Europe [after the twelfth century]. One very practical effect of this was on working conditions. In the cold and dark northern half of Europe people could now work for longer hours and with more precision because they were shielded from the elements. The light poured in, yet the cold was kept out. Prior to glass only thin slivers of horn or parchment were used and the window spaces were of necessity much smaller and the light admitted, dimmer.