The balloon mentioned in Tunnard (pp. 46-47) is not further described - either as to size or composition (hot air or hydrogen). Where this came from is impossible to accertain.
There is absolutely no evidence of military use of balloons in this area. In fact, to the best of my knowledge there was only one use of a balloon for military observation west of the Appalachian mountains. That was during the shelling of Island No. 10 in the Mississippi River. Two ascensions were made under the auspices of the Navy to observe the effect of the mortar shelling.
As an aside, this action, on the Mississippi River under Naval control could be considered to be the first example of naval aviation!