[time-nuts] Lifetime of glass containers
max at maxsmusicplace.com
Mon Jun 15 19:59:53 EDT 2009
I know that one way they used to make window glass was to blow a big glass
bubble and then roll it flat. Pressure prevented flattening of the last
little bubble. I have seen examples of this kind of glass at Saint
Max. K 4 O D S.
Email: max at maxsmusicplace.com
Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com
To subscribe to the fun with tubes group send an email to,
funwithtubes-subscribe at yahoogroups.com
----- Original Message -----
From: "J. Forster" <jfor at quik.com>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Monday, June 15, 2009 4:34 PM
Subject: Re: [time-nuts] Lifetime of glass containers
> Interestingly, I recently had dinner with an archeology professor,
> interested in the Etruscan period. She had just discovered a flatish piece
> of glass i9n a dig, thousands of years old, and believes it was made
> essentially like rolling out dough on a slab while red hot.
>>> -----Original Message-----
>>> From: time-nuts-bounces at febo.com
>>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Dave Carlson
>>> Sent: Monday, June 15, 2009 12:57 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Lifetime of glass containers
>>> Not to charge in, but I've looked at ordinary window pane
>>> glass in very old buildings and you can actually see the
>>> rippling effect that occurred over time, showing the "flow"
>>> of the glass toward the lower edge of the pane. One presumes
>>> that the panes were relatively uniform when installed 120
>>> years earlier. Sounds liquid to me.
>> Nope.. 120 years ago, I don't think they had modern float glass or even
>> continuous casting processes.
>> You blew a large cylinder, cut it open, and laid it flat in an oven, or
>> took molten glass, poured it onto a flat surface, rolled it flat, then
>> polished it (with a "plate" hence the name "plate glass")
>> Sometime early in the 1900's they started making glass in a sort of
>> continuous casting process with slots or rollers or some such scheme to
>> make sheets, but it wasn't very flat in an optical sense.
>> After WW II, they developed the float glass process, where the molten
>> glass is floated across liquid metal, giving you continuous production
>> flat surfaces.
>> So, what you're seeing in old buildings is the fact that flat glass was
>> really hard to make and expensive. You might use it in a mirror, for
>> instance, if you didn't use polished metal instead.
>> I'm sure wikipedia has more than anyone would want to know about sheet
>> glass manufacture..
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> and follow the instructions there.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> and follow the instructions there.
More information about the time-nuts