Is "transitu" an instance of a supine, in the ablative case, as ablative of separation??
I'd say not, hlawson. It may seem strange but it's just the ablative of the noun "transitus -ûs". You seldom find supine + verb. (A&G, §510, n.4)
Not strange at all, adrianus; I overlooked the noun transitus, -us in the dictionary, which led to my question. But it was a useful mistake, for it was the first time I'd really studied the supine. Next time, I'll look harder in the dictionary.