Solarized glass and the change to selenium as a decolorizer.

     The switch to selenium as a decolorizer began before WWI.  Because the
Owens Automatic Bottle-Blowing Machine worked from a tank furnace, it
helped bring about the switch to selenium.  Manganese dioxide was not very
stable in a tank furnace because it is difficult to maintain an oxidizing
atmosphere in such a furnace.  Selenium was much more stable in that
environment.  One of the earliest publication of information on the used of
selenium as a decolorizer came out in 1911 (Angus-Butterworth 1948:68-69).
Keep in mind that the half of the bottles produced in the United States in
1917 was being made on the Owens Machine.  I have not seen very many
solarized Owens-made bottles.

Angus-Butterworth
     1948 The Manufacture of Glass.   Pitman Publishing Corp. New York

For a discussion of this transition, see "Impact of Mechanization in the
Glass Container Industry: The Dominion Glass Company of Montreal, a Case
Study."  Historical Archaeology 1983 volume 19, no. 1:38-50.

     Tony McNichol and I gave a paper at the SHA on dates for
suction-scarred bottoms and we have been gathering information on the
subject.  Opinions we do not need, however comments with citations would be
most appreciated.