can't find name of 17th century style glass inserts

[lintek44]

I am happy to have found your web site  and hope that someone has an answer to my very vague question
 I am frustrated from googling and can not for the life of me find the name of a particular type of glass that was used in cabinetry, (Upper cabs) during the 17th century time period. It could be an earlier period or later. I work for a family run custom cabinetry dealership and we have a display that we just had put in. the upper cab doors have an oblong opening in them so we can insert hand crafted glass.
the cabinets are shaker style and somewhere in my memory banks I can see there being a particular glass that was used maybe in England? the glass inserts have circles blown into the glass like bottoms of coke bottles but their actually not soda bottles. the glass also would probably consist of little tiny air bubbles strewn through the glass and you would not beable to see through the glass clearly.
anyone have the answer?
I would be very very grateful so I could rest peacefully not being tortured trying to search on the internet for this type of glass.  No one has it.
thank you,

Lintek

[Della]

Hi Lintek,

Welcome to the board.
This is the extent of my knowledge I'm afraid.

Flat glass for windows was still rare during much of the 17th and 18th centuries. Small panes were made by blowing a large glob of glass, removing it from the blowing iron and then rotating the glass quickly so it would spread and flatten. Such glass had a dimple in its center, many air bubbles and a pattern of concentric circles

As far as I am aware, this is known as bulls-eye glass, but maybe other members will know better.

[Ivo]

These are called Bullions or Bull's eyes - I would not think you'd have trouble sourcing these.

[Adam]

Yes, the earlist window glass was made in the way described, spinning it out to form a disc.  This would be cut into rectangles with the most blemish free used for quality windows.  The "bull's eye" in the middle was regarded more or less as a second and used for low-grade jobs.

Nowadays, of course, they keep the middle bit for trendy purposes and throw away the rest.  That's progress!

Adam D.

[lintek44]

If only they could see how far progress has come along.
I'm constantly  amazed at the speed of it.
 It seems like every day there's something new on the market in technology. Suprised they haven't made flying cars yet that can fly above traffic when stuck in it. How far can we go?
many thanks to all of your answers,
I find this very helpful indeed,
Sincerely,
Linda

[Urchin]

The "Bullseye" glass mentioned above would've been produced using the "Crown sheet" method,the glass being blown and rotated to form a large disc that was then cut up into the required sizes ; it was thin,uneven and easily broken. The "bullseye" was in fact the centre of this piece of spun sheet,being the Pontil iron shear mark such as you would find on any early  mouth blown article of the same period.
Another type of glass sheet used for glazing of furniture and windows is "Broad sheet" which was introduced c.1618 from Venice ; this was blown glass formed into a cylinder,slit down the middle and heated until it opened up into a flat sheet. It was thicker,more even and smoother than Crown glass,but restricted in size.It can be recognized by  slight  irregularities in the glass surface ie ripples and bubbles etc.
"Plate glass" is another type of manufacturing process and is far superior to both previous types ; it can be made into much larger,smoother and thicker sized "panes".

Extracted from Glass- M&G Payton  1976. Hope this helps! Best wishes-Urchin.

[Glassyone]

Now the glass is identified----
According to my son they have made a motor bike which can fly for two hours. Still a prototype. Looks like a cross between a helicopter and a plane, ridden like a bike.  :shock: