Roman blue glass fragment

[Russ]

Hi Folks,

     Attached is a photo of a millifiori glass fragment of opaque white and yellow glass in a translucent to clear blue glass matrix. What I find interesting, even amazing, is the fact that the inside does not look like the outside. It seems as if they made two objects, an inner one and an outer one and fused them together... the object might have been a bowl, cup or vase of some kind.
     As it appears, it measures 34 mm long x 25 mm wide x 3.5 mm thick, and weighs 5.84 g.
     This fragment is curved. I measured the length of the outside arc 30 mm; placed a straight edge from end to end, and measured the height of the arc 2.5 mm. Do we have a math whiz who can determine the approximate diameter of the item from these measurements? It would be interesting to find out.
     Thanks.
Russ

[mauseus]

Hi,

If the height (h) is 2.5 mm and the flat distance between the ends (w) is 30 mm then the radius (r) is 46.25 mm so the circumference is 296.6 mm.

r= (h/2)+((WxW)/8h)

Then circumference (c) = 2 x pi x r

Regards,

Mauseus

[benito]

Hi,

If the height (h) is 2.5 mm and the flat distance between the ends (w) is 30 mm then the radius (r) is 46.25 mm so the circumference is 296.6 mm.

r= (h/2)+((WxW)/8h)

Then circumference (c) = 2 x pi x r

Regards,

Mauseus

This individual would have done better.

[mauseus]

Hi,

Are you suggesting I'm wrong?

Mauseus

[benito]

Not me. Pythagoras.
c= 2  x pi x r
c= 6.28 x 46.25
c=  290.45

[mauseus]

Hi Benito,

I see where YOUR error is, you've used an approximation of pi.

3.14 is a very shabby approximation but is ok, I guess, for this estimation.

Mauseus

[benito]

Would this approximation be OK
31415926535 8979323846 2643383279 5028841971 6939937510
5820974944 5923078164 0628620899 8628034825 3421170679
8214808651 3282306647 0938446095 5058223172 5359408128
4811174502 8410270193 8521105559 6446229489 5493038196
4428810975 6659334461 2847564823 3786783165 2712019091
4564856692 3460348610 4543266482 1339360726 0249141273
7245870066 0631558817 4881520920 9628292540 9171536436
7892590360 0113305305 4882046652 1384146951 9415116094
3305727036 5759591953 0921861173 8193261179 3105118548
0744623799 6274956735 1885752724 8912279381 8301194912

[Russ]

Hi Mauseus and Benito,

     Thank you very much for your expertise. It is greatly appreciated! That would make it a good size bowl.
     Thanks again.
Russ

[*Alex]

Hi Russ,

Here is an old thread on Roman glass which you might find a bit more interesting than benito's off-topic obvious troll posts.  

https://www.forumancientcoins.com/board/index.php?topic=37448.0

Alex

[benito]

Absolutely on-topic comments. The owner of the fragment asked for the possible size of the artifact . I only corrected some mathematical errors.

[Russ]

Hi Friends,

     Since the inside is different than the outside, I am assuming two glass bowls were were formed, then one was fitted into the other while still molten. I always thought this technique was invented in Germany/Prussia for the invention of Fredrick the Great's double wand glass/es which were given as souvenirs after his hunting parties.
     Any comments on this manufacturing technique?
Thanks.
Russ

[stlnats]

Sounds like cased glass.  Can be very elaborate or just different layers of solid color (or clear), or both.  The ovens, etc are different, but many of the techinques are the same as in classical times.  I've talked with artisans at local art fairs and its amazing how they plan and build up the indvidual layers to form the final look.  Ancient glass workers were no less creative. 

Here's a basic explanation:

http://www.ehow.com/about_5037912_cased-glass.html

 

[Heliodromus]

I'm not dead yet.

[mauseus]

Hi,

Absolutely on-topic comments. The owner of the fragment asked for the possible size of the artifact . I only corrected some mathematical errors.

What errors? The errors were in you using an approximation of pi Benito.

Regards,

Mauseus

[Russ]

Hi Folks,
     Thanks for all your input. It is fascinating and appreciated.
Russ

[carthago]

My math skills are easily eclipsed by my 5th grader and I always thought Pi was best served with ice cream, but I do think those pieces of glass are beautiful. 

[Joe Sermarini]

Absolutely on-topic comments. The owner of the fragment asked for the possible size of the artifact. I only corrected some mathematical errors.

On topic or not, I know it was supposed to be humorous, but many of our members don't get your humor and they complain to me.   

[Russ]

Hi Folks,

     There certainly is a lot of passion and dedication here. I didn't detect any open hostility or animosity, just eagerness to provide information.
     Thank you all and I'm sorry if my post created conflict of any kind.

Russ