History of plate glass manufacture

Information on the history of plate glass manufacture is sought.
Evidence to look for in attempting to assess the date of manufacture
of plate glass sheets is also sought. Thanks for any assistance,

Thea Burns
Assistant Professor and Paper Conservator
Art Conservation Program
Queen's University

                                  ***
                  Conservation DistList Instance 10:53
                Distributed: Thursday, December 5, 1996
                       Message Id: cdl-10-53-007
                                  ***