In the south, where the Federal strength was less, matters for a few days looked more promising for the Sonderbund. On November 17th a body of 2000 men, with four guns, crossed the St. Gotthard Pass in a storm of wind and snow, and fell upon Airolo. The Ticino troops, who were holding that place, 2700 strong, hardly expected a visit in such weather, and allowed themselves to be surprised. Before they knew what was happening, the village was surrounded by the riflemen of Uri, and cannon-balls were crashing through the snow-covered roofs. They fled in disorder to Bellinzona, with a loss of six killed and thirty wounded, leaving weapons, ammunition, baggage, even their colonel’s despatch-boxes and dressing-case, in the enemy’s hands. This was the nearest approach to success which the Sonderbund had. It was hoped that Ticino, being a Catholic canton, at least a portion of the population might welcome the invaders; but they received no encouragement, and in a few days the approach of the Federal army to Lucerne rendered their retreat necessary. For Dufour did not let the grass grow under his feet. Two days after the capitulation of Fribourg had been signed, his headquarters were at Aarau, the capital of Aargau, and all his dispositions made for striking the decisive blow. Lucerne is very well situated for defence against an enemy approaching from the north. The stream of the Reuss, flowing out of the lake towards the north-west, presently sweeps round to the north-east. Just at the angle the smaller River Emme joins it from the south-west, so that a continuous obstacle is offered to an attacking force. Between the Reuss and the Kussnacht arm of the lake (which washes the foot of the Rigi) is a range of lofty wooded hills called the Rooterberg, which continue almost to the Lake of Zug; and in the other direction, a similar line of hills, cut by deep gorges, runs parallel to the Emme. It was on this latter side that the ill-starred attempt of the Free Corps had been made in 1845. Dufour determined on this occasion to approach from the other direction, along the line of the Reuss, and between that river and the Rooterberg. It was a hazardous operation: in his own words, “taking the bull by the horns.” Gislikon, the point where the main road crosses the river, while that on the right bank comes close to it, was strongly fortified; and the Rooterberg afforded an admirable position for sharpshooters and artillery. But by advancing from this side he would, if successful, separate Lucerne and Schwyz, and would strike at the heart of the secession. Therefore, while ordering all the five divisions which he intended to employ, to converge by various roads on Lucerne, from east, north, and west, he resolved to make his main attack with the fourth and fifth, under Colonels Ziegler and Gmür. Of these, the former was at present quartered in Aarau, the latter between the Reuss and the Lake of Zürich. [Illustration: BATTLE OF GISLIKON.]