While tossing about boxes in the household storage looking for something, a box of very old and unused Christmas stuff fell and out rolled a plastic tree bobble. I intended to quickly stuff it back in, when I was stuck by the shape and size. My wargamer brain kicked in immediately and I thought...hmmm....it may just work!
So later that evening I put everything else aside and tried to be inventive. What I had seen was a balloon, a 15mm-ish sized balloon from the 'ribbing' typical of the Christmas tree ornaments. Well, long story short, I finally came up with a facsimile of a period balloon. Certainly not historic by any means and certainly not even structurally feasible, probably not aerodynamic to be sure, but kinda looks the part.
Absolutely no mathematics was involved in the following! I merely started by eyeballing the height which I thought was high enough to look the business but as low as possible to not make it too top heavy. (ed. ~8") Needing to firmly anchor the, thankfully, light weight bobble/balloon I used a rod of aluminum which I twisted around a real twig/ scale tree. It was further anchored by using one of the 15mm OldGlory weird poses, in this case a soldier heaving a large rock over his head (!) and drilled a hole through what would have the rock and fed the rod through the now grasping hands and then up into another hole drilled in a solid cube of balsa wood forming the basket and thus finally into the hollow interior of the upside-down bobble.
"Engineeringly speaking" I have thus placed all this light weight directly over the anchor point for stability which is further helped by the tree "buttress". All this on a card stand with a surprising and welcomed, small table "footprint".
I gathered some 'green stuff' to to create the loose part of the balloon under the inflated part which further hides the wire. The wire, while very thick in scale (hey it was what I had at hand!) was painted to look like rope. While ideally I would have liked to have more soldiers holding the rope none were at hand, so I would hate to be that poor soldier who seems to be that close to being suspended himself, but he makes the use of the wire look like a guiding rope hanging from the basket and thus perhaps the illusion of a flying American Civil War observation balloon.
A few quick photos before I get on to other more pressing stuff.