John Rognes has communicated these details about Abel's time in Switzerland:

Dear Rahul, The map was drawn by me, based on the place-names mentioned in the biography by Stubhaug (and perhaps also on an older one by Øystein Ore), so it may not show the precise route. Chapter 41 in Stubhaug's biography starts in the Dolomites in June 1826. He traveled with four other Norwegian students: B.M. Keilhau studied geology, C.P.B. Boeck was to become a veterinarian, N.J. Møller and N.O. Tank studied engineering/mining. On June 27th Abel and Tank left the other three behind in Bolzano, and traveled to Innsbruck and west toward the Bodensee/Lake Constance, but when they got to Bodensee they thought it would be interesting to go by Zurich to see more of Switzerland. Abel sent a letter from Zurich on July 5th. They planned to continue through Zug, along the Zugersee/Lake Zug, and toward Mont Rigi, where there should be a good view towards the Alps and over the Vierwaldstätter Lake in the direction of Luzern. They climbed Mont Rigi, perhaps to Kulm, and then journeyed to Luzern and Basel. There Tank learned of a great fire in his home town Fredrikshald, so he returned home, while Abel traveled directly to Paris, arriving on July 10th. - John