The line Bialystok-Brest-Litovsk was the main field selected, because of its central location between the Austro-German frontiers, and more particularly because it was well covered from attack by the intrenched fortress and camp of Warsaw. The troops and reserves from Little Russia, especially from the Kiev district, were readily available on lines converging to the Austrian city of Lemberg in Galicia, and, it was estimated, could take the front in ten days. From this district five army corps are raised. From the Odessa district to the south two more army corps could be counted upon, and these could reach the scene of operations in twelve or thirteen days. In actual speed of mobilization the Austrian army was ready first, but the Russian army protected and covered the slow mobilization and concentration of its forces by a dense curtain of cavalry masses, for which task the rapidly mobilized Cossack cavalry was especially well fitted. These cavalry engagements--for the Russians were met by the Hungarian cavalry--effectually screened the actual gathering of the armies, and led Austria into the error of supposing Russia to be quite unready. But, although Austria had been the first to begin actual mobilization, her strategic railways on the frontier were so poor that it was not until August 10, 1914, that she was ready to advance, and even then that single line of railroad running from the Bug to the Vistula was deficient in rolling stock. Austrian military organization was excellent, Hungarian railroad organization was utterly inadequate to cope with the sudden requirements of modern warfare.