Mass production (of sorts) was lost. The Romans had some fairly standardized weaponry during the early and middle Empires, though this changed later on.
Lost in Europe you mean. China retained it; their crossbows had interchangable parts.
Mass production (of sorts) was lost. The Romans had some fairly standardized weaponry during the early and middle Empires, though this changed later on.
No, Not really and somewhat.
The trade uses changed involving bigger loads (at the point where Gaul merchant used camels) with less dense flux. I council everyone to read Henri Pirenne works about high-medieval trade.
The commerce, including international one, was still going and not at all loss. Even the Muslim closure of Mediterranea never severed totally the western-easter trade (more the western-byzantine trade, and only for a moment).
And for Northern Europe, actually these regions were opened for the first time to a more dense international travel : Saxe, Frisia, Bavaria, etc became connected to Mediterranean trade like never they were before.
So not only trade significantly lowered during the high middle ages after Roman Empire fall, but region benefited of it for their trade dynamics.
For the urban civilisation...Yes and no. Yes, the cities knew a real decline during the first centuries in some lands that were often the less romanized anyway. (But in mediterranean Gaul, in Italy and Hispania, city kept a major role).
The saracenic, norman and hungrese raid helped paradoxally to separe the viable cities from the ones they're not (mainly created by roman for their own purposes). But the remaining knew a flourishing era since the XI.
And actually, the city role never really disappered. In southern France, it was not really about the demographical importance, but its political : you have towns of 2000 inhabitants that were considered as cities with their own leaders.
A city like Tolosa was considered as a republic by the contemporaries.
I was referring to soon after the collapse , not the High Middle Ages.
The medieval Northwestern European tradition of the bathhouse (heated water in tubs, commercial operations, medical and/or personal services on offer) is a very different thing from the roman baths, and separated from them in most of the areas it existed by at the very least 500 years. That is about as far back as the Aztec Empire. I find it very diffilut to argue continuity, especially since that's obviously not necessary (we have continiuty in the Mediterranean, even with some bath complexes remaining in use).
For western Europe, both Andalucian baths and Christian etuves (i don't know the word in english)