Quote:
Originally Posted by Boater Sam
It is an urban myth, usually?
It came about due to folk finding very old window glass that was thicker at the bottom than the top.
However, you have to realise how this really old glass was produced.
"Flat" glass was made by spinning to produce a disc that was then cut up. The poor people could buy the center parts ie. the 'bullseye' where the pintle was, cheaper than the outer parts.
Later glass was drawn up from the melt on a circular former to produce cylinders which were then slit lengthways and opened out whilst still plastic.
This produced the inevitable distortions, ripples, where the glass was different thicknesses.
Mechanically rolled glass is made usually in obscure and wired patterns due to the surface not being perfect unless polished afterwards, hence can have thickness variations too.
Now, think of the glazier faced with a pane of glass thicker at one end, of course he would tend to put the thick bit at the bottom of the pane to reduce the squeezing out of the putty.
Molten tin lehr "Float" produced true flat glass has been around for a long time, I have taken out thousands of pieces and never found one thicker at the bottom.
But if you are convinced that the super cooled liquid continues to flow in a period of only 100 years, so be it, who am I to argue, I'm not that old, yet.
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Very good post, however in between the spinning a gob of glass on a metal rod to obtain a circle of glass, and the method of feeding it between rollers. There was another method, which was the one that gave the roller idea. a "gob" of molten glass was attached to a blowpipe and blown, it was then swung until it stretched, and the blowing continued, eventually you ended up with a cylinder about 3 feet long, chop off the ends, slit down the middle and place back in the lehr, to anneal and flatten.
It's funny but most of my family were involved with the local glassworks, my paternal grandmother polished glass for mirrors, her husband (my grandfather) worked in the packing warehouse. my father was a plumber in the same company, and my mother, well she delivered parts for a hydraulic company, quite often to the glassworks!
I became an apprentice electrician, in a steelworks instead of taking up the offer of a plumbing apprenticeship with the glass firm. I used to joke that I was the only one who had escaped the family tradition, however years later I'd grown fed up with the electrics, and for a while became a dog handler. Imagine my surprise when one day I answered an advert for someone to run the dog section at a local firm, I got the job, then found out who's dog section I'd be in charge of, yes you guessed it, the glassworks.
