On August 1, 1811, the brothers Johann Rudolf and Hieronymus Meyer from Aarau, accompanied by two chamois hunters from Valais and the mountain guides Joseph Bortis and Alois Volken, came over the Lötschenlücke on the Great Aletsch firn. They were equipped with food, wood, a collapsible ladder, poles and ropes. They reached the foot of the Kranzberg, where they established their camp for the night. Early in the morning they set out and climbed up the Jungfrau firn. Since the glacier was very rugged in some places, they had to use the ladder to get ahead. When they had the Jungfrau summit in front, a Föhn storm broke out and they had to return empty-handed. Towards evening they built the camp for the night at the Mittelfluh.
In the morning of August 3. four of them left again to climb the Jungfrau. The four crossed the Jungfrau firn and climbed the steep and icy slopes up to the Rotthalhorn. With the help of a rope, which they attached at a cane deeply pushed into the snow, they slid down the Eisgrat to the Rotthalsattel. With difficulty, half sitting, half climbing, they overcame the sharp ice ridge leading to the top, looking left and right into the abyss. After crossing a deep firn crack, they stood in the afternoon at two o'clock on the summit.