After Henri Pieper's death in 1898 sources give that the firm exclusively used Siemens Martin steel, so I wonder if they were sourced for tubes. PeteM can correct me, but it appears about this time that the Belgians were churning out about 1.5 million barrels a year.
Peter, you may be correct in your interpretation and as you say the info is a snap-shot into the sourcing at a specific point in time. Economics, War, etc., changes sourcing lines as well as advances in technology.
Raimey,
I have exact numbers buried somewhere in my research. But I would say you are in the ball park, perhaps even a little low.
It is important to know that at this slice in time Pieper was dealing with them. It certainly gives us a picture of how big they really were then. It is also interesting to note that about this time the Germans were complaining about the Liege proof house. Through the Brussels Convention they forced higher proof pressures to be used. Because of the war, it did not happen in Belgium until much later.
Pete
