The Prussian army, if assembled in Upper Silesia, would be at the point of Prussia nearest to the Austrian capital; if assembled at Görlitz,[7] it would interpose between Berlin or Breslau and an Austrian army approaching from Bohemia. These were, therefore, the most favourable points of assembly, the one for attack and the other for defence. But the position in Silesia would lose much of its value unless it were intended, as soon as the army should be ready, to march on Vienna; and this course in the middle of May was, to the king's mind, inadmissible. There was, however, a second quite unanswerable argument against assembling the whole army at either place. The movement could not be carried out in a reasonable time. To march to either district from the distant provinces would have been an affair of many weeks, and the concentration would run the risk of being too late. The difficulty could not be overcome by the use of the railways. To move a whole army corps by a single railway required, according to the nature of the line, irrespective of the distance, from nine to twelve days. But for the transport to Upper Silesia only one, and for that to Görlitz only two, through railways were available, so that a very long time would be required to move the whole army by rail to either point. Moreover, neither of the districts in question is so fertile as to be able to feed a large army for more than a few days. As the king was determined not to fight, if fighting could be avoided, it might become necessary to keep the army waiting for some weeks after its concentration. This would be to starve it before a shot had been fired. Thus it was impracticable in the political circumstances to collect all the nine corps into one army, either for offence or defence. Separate armies had to be formed, and considerations of defence to prevail. The principal centres of concentration were fixed in the neighbourhood of Görlitz and of Schweidnitz, points on the lines of an Austrian advance towards Berlin and Breslau respectively from Northern Bohemia, where at this time (the middle of May) the Austrian army was believed to be assembling.