There would remain, therefore, on the basis of the 1913 output, 130,700,000 tons, or, deducting consumption at the mines themselves, (say) 118,000,000 tons. For some years there must be sent out of this supply upwards of 20,000,000 tons to France as compensation for damage done to French mines, and 25,000,000 tons to France, Belgium, Italy, and Luxemburg;[43] as the former figure is a maximum, and the latter figure is to be slightly less in the earliest years, we may take the total export to Allied countries which Germany has undertaken to provide as 40,000,000 tons, leaving, on the above basis, 78,000,000 tons for her own use as against a pre-war consumption of 139,000,000 tons. This comparison, however, requires substantial modification to make it accurate. On the one hand, it is certain that the figures of pre-war output cannot be relied on as a basis of present output. During 1918 the production was 161,500,000 tons as compared with 191,500,000 tons in 1913; and during the first half of 1919 it was less than 50,000,000 tons, exclusive of Alsace-Lorraine and the Saar but including Upper Silesia, corresponding to an annual production of about 100,000,000 tons.[44] The causes of so low an output were in part temporary and exceptional but the German authorities agree, and have not been confuted, that some of them are bound to persist for some time to come. In part they are the same as elsewhere; the daily shift has been shortened from 8-1/2 to 7 hours, and it is improbable that the powers of the Central Government will be adequate to restore them to their former figure. But in addition, the mining plant is in bad condition (due to the lack of certain essential materials during the blockade), the physical efficiency of the men is greatly impaired by malnutrition (which cannot be cured if a tithe of the reparation demands are to be satisfied,--the standard of life will have rather to be lowered), and the casualties of the war have diminished the numbers of efficient miners. The analogy of English conditions is sufficient by itself to tell us that a pre-war level of output cannot be expected in Germany. German authorities put the loss of output at somewhat above 30 per cent, divided about equally between the shortening of the shift and the other economic influences. This figure appears on general grounds to be plausible, but I have not the knowledge to endorse or to criticize it.