The loss of iron-ore in respect of Upper Silesia is insignificant.

The exclusion of the iron and steel of Luxemburg from the German Customs Union is, however, important, especially when this loss is added to that of Alsace-Lorraine.

It may be added in passing that Upper Silesia includes 75 per cent of the zinc production of Germany.
[54] In April, 1919, the British Ministry of Munitions despatched an expert Commission to examine the conditions of the iron and steel works in Lorraine and the occupied areas of Germany.

The Report states that the iron and steel works in Lorraine, and to a lesser extent in the Saar Valley, are dependent on supplies of coal and coke from Westphalia.

It is necessary to mix Westphalian coal with Saar coal to obtain a good furnace coke.