Hi John,
Yes, the rod goes all the way through and is attached with nuts to the base. The rod is a long piece of hollow all thread with a decorative textured piece of clear glass tube around it to mask it's appearance. It actually seems to take the stress off of the glass by simply holding the glass in place firmly, but transferring any real stress to the metal base, or to just above the cap assembly at the top. It actually appears that if the glass were broken away or missing on my lamp, it would still stand and be functional, and the glass is merely done in a way that it is a cosmetic addition and not a structurally functional part of the lamp. Another aspect of the design of my lamp is that the base has additional weight in it, to offset the weight at the top. Without the weight at the bottom the piece would be very top heavy and would topple quite easily.
Since my glass is transparent and not translucent , it is easy to see that the thickness of it is about the same at all points of the body and neck. In looking at yours, my guess is that they drilled the piece on the side for a wire, and then realized that without a hole at the bottom in the center it would be quite difficult to attach all of the necessary large hardware to make the lamp functional and also build a lamp that would appear to be in scale with a shade on it. It also appears that the internal dimensions of the neck on your glass may have prohibited the insertion of a reasonably thick rod to support it all, so they abandoned the project.....
I think Ivo may be able to attribute the glass.. at least that would be my gut feeling.... I do not think that many companies would have produced this shape and size of glass.....
Pretty vase though.....
Pieces that large seem quite uncommon from what I have been able to determine.....
My Emerald green version of the lamp has a glass body that is around 24" in height, with the same shape and about the same body size.... just a little shorter neck....
Craig