Already, both in Silesia and in Europe, good progress had been made. No Austrian armies disputed Frederick’s advance, for Charles VI’s grandiose projects had denuded his home provinces of troops. The natural defences of Silesia, too, were all on the wrong side. Mountains formidable though by no means impassable screened it from loyal Bohemia and loyal Moravia, and thus blocked the direct paths to Vienna. Only a few hills and streams barred an attack from the side of Saxony and no natural obstacle intervened between Breslau and Berlin. The strong portal looking towards Prussia was Glogau, which closed the Oder, the great natural highway of Silesia. Breslau, the capital, a city which Frederick could praise as the finest in Germany, was too big to be a fortress by nature and too independent to be made one by art. In the main Protestant, and therefore ill-disposed towards Austrian rule, it stood firmly upon its right to provide for its own defence and refused to receive a garrison. Glogau was therefore the only formidable fortress in Lower Silesia, the half of Silesia where Protestant feeling was strongest and which was most exposed to the Prussian invasion. The south-eastern half, Upper Silesia, contained two other strong places of high importance—Brieg, which commanded the upper Oder, and Neisse, which secured the backdoor of the province towards Austria. But Glogau, Brieg, and Neisse were all ill-supplied and undermanned. Without a field army to use them as bases and supports they could not oppose a serious obstacle to the army of the King. [Illustration: THE BOARD OF FINANCES AT NEISSE. FROM A STEEL ENGRAVING.] Frederick’s worst foe, indeed, was the weather, which tested the endurance of the Prussians and found it great. Torrents of rain fell from the eighteenth of December to the twentieth. “Waters all out,” says Carlyle of the latter day, “bridges down, the country one wild lake of eddying mud. Up to the knee for many miles together; up to the middle for long spaces; sometimes even up to the chin or deeper, where your bridge was washed away. The Prussians marched through it, as if they had been slate or iron.... Ten hours some of them were out, their march being twenty or twenty-five miles; ten to fifteen was the average distance come.”