crown-glass

crown glass

noun
1.
an optical glass of low dispersion and generally low index of refraction.
2.
an old form of window glass formed by blowing a globe and whirling it into a disk.

Origin:
1700–10

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To crown-glass
Collins
World English Dictionary
crown glass
 
n
1.  another name for optical crown
2.  an old form of window glass made by blowing a globe and spinning it until it formed a flat disc

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature