Wednesday, July 27, 2016


 Toledo Ohio used to be a manufacturing center for glass. It's gone now, but like many things, there are people that remember and want to commemorate that history. To that end, they built a lovely museum.

All I bring myself to do is offer this quote from the website:
One of the distinguishing features of the pavilion is that all of the exterior and nearly all interior walls are large panels of curved glass, resulting in a transparent structure that blurs the boundaries between interior and exterior spaces...Toledo was once a major center of glass production; now most of its factories are closed and the glass workers gone. The enormous sheets of glass needed for the pavilion were manufactured in Germany and molded in China.

1 comment:

Will said...

I'm not surprised about Germany. They have been a high quality glass producer for at least a century. Cameras, microscopes, telescopes, periscopes, you name it, they made the best, or at least as good as anyone else could.

Neat fact: Optical cement originated in Canada, and the Germans didn't have access during ww2, so the high quality lenses in periscopes (and other items) were wrung together sans glue.

You get two glass surfaces that match each other near perfectly, and touch them together, you can watch the air evacuate between them. They may never come apart, especially if they are absolutely clean. Tends to require heat and/or force to move them, and I've had them break chunks off, rather than separate.

One of the ultra-high quality doublet lenses I used to work with originated in Germany. The glass was termed a "melt", and it took a year from ordering to get a formed, ground, and coated lens in the door. The same for the matching prisms. Then I had to measure them on a laser interferometer to ensure they met specs. Not easy, since the specs were right on the edge of what the laser system could do. Some days it couldn't do it. You know you are pushing the limits when the equipment has bad days!

That lens with two prisms would probably fit into a normal coffee mug, and cost $2k +$1k/prism, in the early 80's. It was used to replicate 1micron line width geometry on silicon wafers.