During that exchange there was appeal to the Imperial Dictionary, ed Fairbairn, 1874, responded to by Mung, here.
Accordingly, courtesy Web Archive, I clip the entire relevant section of the article on the cross, to clear the air:
I trust this (and this plus this) will suffice for any fair minded person to see much of the reason why many informed people are willing to accept the traditional understanding that Jesus was crucified on a t-shaped cross . . . or, a bit less likely a T with the placard bearing the accusation nailed on at the top. END
PS: One may ask, why bother. In reply, first Christianity is a faith that rests on history so we must have a high regard for historical accuracy. However, there is more. It is evident that the Watchtower society, since the 1930's, has made an argument that the typical cross shape that we see is a pagan import and a sign of apostasy, linking it to Tammuz and whatnot, citing a few scholars in attempts to support the claims, and the additional one that stauros, the Greek word used, specifically means and demands that it be understood as only an I-shaped stake on which our Saviour would have been nailed up with his hands pinned together over his head. When it is pointed out on evidence [cf the above links and the clip] that meaning is driven by usage at the relevant time and place, and that this in C1 Palestine etc under Roman rule implied crosses of forms T, t, X, Y (a forked tree as an expedient), or I, and the further textual evidence narrows us down to T and t, especially on Jesus being compelled to carry the cross-beam . . . patibulum, all sorts of dismissive arguments are employed. Thus, we see a well-poisoning, polarising, truth-clouding tactic at work, which creates an improper alienation and a contemptuous attitude to Christians who may have Bibles with Crosses on their cover, or attend services at churches that use crosses as symbols, or who may wear a cross as a symbol of the Faith, or whose family members may be buried under Tomb stones with crosses or in the shape of crosses. Indeed, if one seeks to correct persistently on the evidence of history and language, one may be accused of being hateful. In response, let us simply clarify that the issue is the historic usage in C1, which favours t or possibly T. And Christians who use the cross as a symbol, are not thereby announcing their apostasy and paganism. Enough is enough.
PPS: For a general response to Jehovah's Witnesses and their many claims, I suggest here at CARM and onwards. For a quick overview, try here. For what I think serious Christians need to know in this day and age of severe and mounting pressure and attacks, try here on and onwards. Here, is a Biblical point by point justification of the classic 325 and 381 Nicene Creed which is based on 1 Cor 15:1 - 11 with an introduction and a follow up to the parousia.
