This thickening is due to the way pane glass was manufactured in the 19th century and earlier not due to its deformation as a super-cooled liquid. aa On Friday, January 30, 2004, at 09:55 AM, Bewley, Nigel wrote: > Okay...how do we account for window glass that has become thicker at > the > bottom of the pane than at the top? Apparently glass 'flows' over > time - > years not weeks - and window panes change shape! > > Nigel > British Library > > -----Original Message----- > From: Don Cox [mailto:[log in to unmask]] > Sent: 30 January 2004 15:00 > To: [log in to unmask] > Subject: Re: [ARSCLIST] stability of shellac disks > > On 30/01/04, Art Shifrin wrote: >> "I have shellac records over a century old which exhibit no >> deterioration other than wear! >> Steven C. Barr" >> >> How do you know that the disks have not in some way changed or >> deteriorated? >> >> Yes, they're playable but even glass changes shape over time. > > I saw an exhibition of Roman glass a few years ago. Those bottles etc > didn't show any signs of having changed shape over 2000 years. > > Regards > -- > Don Cox > [log in to unmask] > > > *********************************************************************** > *** > > Experience the British Library online at www.bl.uk > > Adopt a Book this season ! Help the British Library conserve the > world's > knowledge. www.bl.uk/adoptabook > > *********************************************************************** > ** > > The information contained in this e-mail is confidential and may be > legally > privileged. It is intended for the addressee(s) only. If you are not > the > intended recipient, please delete this e-mail and notify the > [log in to unmask] : The contents of this e-mail must not be disclosed or > copied without the sender's consent. > > The statements and opinions expressed in this message are those of the > author and do not necessarily reflect those of the British Library. The > British Library does not take any responsibility for the views of the > author. > > *********************************************************************** > ** >