Why were the ingots mostly round?

[Jens Nordlunde]

B.I you are trying to pull my leg. Well anyway, the thing is like this, there were many forms of ingots, although most were likely to be of the round kind, and they were found in many weights. From what I have seen in the books, the weights were from a few hundred grams to several kg. It also seems as if the form had to do with, if the ingots were transported over land or by boat.